Thursday, October 13, 2011

Kiểm tra chính tả bằng phần mềm check spell

Download here or here
Đây là phần mềm kiểm tra chính tả rất hay, đối với office 2007 hay 2010 sau khi cài thì sẽ xuất hiện mục addin, vào đấy lựa chọn những thứ cần thiết


Chú ý những bảng mục lục hay bảng biểu không nên dùng phần mềm này để check

Monday, October 10, 2011

Wednesday, October 5, 2011

Explain results of Stochastic production frontier model

The output from frontier includes estimates of the standard deviations of the two error components,sigma (v) and sigma(u), which are labeled sigma v and sigma u, respectively. In the log likelihood, they are parameterized as ln2v and ln2u, and these estimates are labeled /lnsig2v and /lnsig2u in the output. frontier also reports two other useful parameterizations. The estimate of the total error variance, 2S = 2v + 2u, is labeled sigma2, and the estimate of the ratio of the standard deviation of the inefficiency component to the standard deviation of the idiosyncratic component,  = u=v, is labeled lambda.

At the bottom of the output, frontier reports the results of a test that there is no technical inefficiency component in the model. This is a test of the null hypothesis H0 : 2u = 0 against the alternative hypotheses H1 : 2u
> 0. If the null hypothesis is true, the stochastic frontier model reduces to an OLS model with normal errors. However, because the test lies on the boundary of the parameter space of 2u, the standard likelihood-ratio test is not valid, and a one-sided generalized likelihood-ratio test must be constructed; see Gutierrez, Carter, and Drukker (2001). For this example, the output shows LR = 0.43 with a p-value of 0.256 for the half-normal model and LR = 1.21 with a p-value of 0.135 for the exponential model. There are several possible reasons for the failure to reject the null hypothesis, but the fact that the test is based on an asymptotic distribution and the
sample size was 25 is certainly a leading candidate among those possibilities.
more detail 
Run stata11/help frontier

Tuesday, October 4, 2011

32-bit and 64-bit Windows: frequently asked questions

32-bit and 64-bit Windows: frequently asked questions
Here are answers to some common questions about the 32-bit and 64-bit versions of Windows.
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What is the difference between 32-bit and 64-bit versions of Windows?

The terms 32-bit and 64-bit refer to the way a computer's processor (also called a CPU), handles information. The 64-bit version of Windows handles large amounts of random access memory (RAM) more effectively than a 32-bit system.

How can I tell if my computer is running a 32-bit or a 64-bit version of Windows?

To find out if your computer is running a 32-bit or 64-bit version of Windows in Windows 7 or Windows Vista, do the following:
  1. Open System by clicking the Start button Picture of the Start button, right-clicking Computer, and then clicking Properties.
  2. Under System, you can view the system type.
If your computer is running Windows XP, do the following:
  1. Click Start.
  2. Right-click My Computer, and then click Properties.
    • If you don't see "x64 Edition" listed, then you're running the 32-bit version of Windows XP.
    • If "x64 Edition" is listed under System, you're running the 64-bit version of Windows XP.

Which version of Windows 7 should I install: the 32-bit version or the 64-bit version?

To install a 64-bit version of Windows 7, you need a CPU that's capable of running a 64-bit version of Windows. The benefits of using a 64-bit operating system are most apparent when you have a large amount of random access memory (RAM) installed on your computer, typically 4 GB of RAM or more. In such cases, because a 64-bit operating system can handle large amounts of memory more efficiently than a 32-bit operating system, a 64-bit system can be more responsive when running several programs at the same time and switching between them frequently. For more information, see Installing and reinstalling Windows 7‍.

How do I tell if my computer can run a 64-bit version of Windows?

To run a 64-bit version of Windows, your computer must have a 64-bit-capable processor. To find out if your processor is 64-bit-capable in Windows 7 or Windows Vista, do the following:
  1. Open Performance Information and Tools by clicking the Start button Picture of the Start button, and then clicking Control Panel. In the search box, type Performance Information and Tools, and then, in the list of results, click Performance Information and Tools.
  2. Do one of the following:
    • In Windows 7, click View and print detailed performance and system information.
    • In Windows Vista, click View and print details.
  3. In the System section, you can see what type of operating system you're currently running under System type, and whether or not you can run a 64-bit version of Windows under 64-bit capable. (If your computer is already running a 64-bit version of Windows, you won't see the 64-bit capable listing.)
To see whether a computer running Windows XP is capable of running a 64-bit version of Windows, do the following:
  1. Click Start.
  2. Right-click My Computer, and then click Properties.
    • If "x64 Edition" is listed under System, your processor is capable of running a 64-bit version of Windows.
    • If you don't see "x64 Edition" listed, your processor still might be capable of running a 64-bit version of Windows. To find out for sure, download and run the free Windows 7 Upgrade Advisor from the Windows 7 Upgrade Advisor webpage.

Can I upgrade from a 32-bit version of Windows to a 64-bit version of Windows 7 or from a 64-bit version of Windows 7 to a 32-bit version of Windows?

You can use the Upgrade option during Windows 7 installation, which preserves your files, settings, and programs, only if you're currently running a 32-bit version of Windows Vista and you want to upgrade to the 32-bit version of Windows 7. Similarly, if you are running a 64-bit version of Windows Vista, you can only perform an upgrade to a 64-bit version of Windows 7. For more information, go to Upgrading to Windows 7: frequently asked questions on the Windows website.
If you want to move from a 32-bit version of Windows to a 64-bit version of Windows 7 or vice versa, you'll need to back up your files and choose the Custom option during Windows 7 installation. Then, you'll need to restore your files and reinstall your programs. For more information about performing a custom installation, see Installing and reinstalling Windows 7‍.
Notes

Notes

  • To install a 64-bit version of Windows 7 on a computer running a 32-bit version of Windows, you'll need to start, or boot, your computer using a 64-bit Windows 7 installation disc or files.
  • If you start your computer using a 64-bit Windows 7 installation disc or files, but your computer isn't capable of running a 64-bit version of Windows, you'll see a Windows Boot Manager error. You'll need to use a 32-bit Windows 7 installation disc or files instead.
  • Windows Easy Transfer can't transfer files from a 64-bit version of Windows to a 32-bit version of Windows. If you're running a 64-bit version of Windows Vista but you plan to install a 32-bit version of Windows 7, you can move your files to an external location manually or use Backup and Restore in Windows Vista. For more information, go to Back up your files and Restore a backup created on a previous version of Windows on the Windows website. (If you're running a 64-bit version of Windows XP, you'll need to move your files to an external location manually.)

Can I run 32-bit programs on a 64-bit computer?

Most programs designed for the 32-bit version of Windows will work on the 64-bit version of Windows. Notable exceptions are many antivirus programs.
Device drivers designed for the 32-bit version of Windows don't work on computers running a 64-bit version of Windows. If you're trying to install a printer or other device that only has 32-bit drivers available, it won't work correctly on a 64-bit version of Windows. To learn how to check for drivers, see Update a driver for hardware that isn't working properly or go to the device manufacturer's website. You can also get information about drivers by going to the Windows 7 Upgrade Advisor webpage.

Can I run 64-bit programs on a 32-bit computer?

If the program is specifically designed for the 64-bit version of Windows, it won't work on the 32-bit version of Windows. (However, most programs designed for the 32-bit version of Windows do work on the 64-bit version of Windows.)
Device drivers designed for the 64-bit version of Windows don't work on computers running a 32-bit version of Windows. To learn how to check for drivers, see Update a driver for hardware that isn't working properly or go to the device manufacturer's website. You can also get information about drivers by going to the Windows 7 Upgrade Advisor webpage.

How can I find programs and devices that work with the 64-bit version of Windows 7?

To find programs and devices that work with Windows 7, look for products that display the "Compatible with Windows 7" logo. They've been tested to be compatible with both the 32-bit and 64-bit versions of Windows 7.
You can also go online to the Windows 7 Compatibility Center and check to see whether the program or device is compatible with the 64-bit version of Windows 7. Hardware and software manufacturers continue to update this information, so check back often.

If I'm running a 64-bit version of Windows, do I need 64-bit drivers for my devices?

Yes. All hardware devices need 64-bit drivers to work on a 64-bit version of Windows. Drivers designed for 32-bit versions of Windows don't work on computers running 64-bit versions of Windows.
To learn how to check for drivers, see Update a driver for hardware that isn't working properly or go to the device manufacturer's website. You can also get information about drivers by going to the Windows 7 Upgrade Advisor webpage.