MySQL tricks

 Produce terminal-friendly output Occasionally you may be using the command line and find yourself limited by the size of either the table you’re getting results from or by the size of the terminal window you’re using. (I find the DPS window particularly resistant to resizing. You can get results in this format column1_name: data column2_name: data instead of the default tabular layout by using the \G flag at the end of your select statement: select * from my_table where id = “132″\G … Continue reading

Configure wamp to send emails

Install hMailServer (http://www.hmailserver.com/index.php?page=download). After that, configure the program: When you first open hMailServer Administrator, you need to add a new domain. Click on the “Add Domain …” button at the Welcome page. Under the domain text field, enter your computer’s IP, in this case it should be 127.0.0.1. Click on the Save button. Go to Settings>Protocols>SMTP and select “Delivery of Email” tab Enter “localhost” in the localhost name field. Click on the Save button. If you need to send mail … Continue reading

Android 9 Patch Image

What is 9 patch? 9 patch is technique used to scale the image in such a way that the 4 corners remain unscaled, but the four edges are scaled in one axis and the middle is scaled in both axis. So the graphical representation of this scenario will be something like this: Image will be divided into 9 patches                    Simple Icon file The image at left side when divided into 9 patch will look like … Continue reading

Android Volley Library

Volley is a library that makes networking for Android apps easier and most importantly, faster. Thousands of apps are written with the help of Apache’s HttpClient or HttpURLConnection. Android Volley is the new way to make network requests. It has a lot of advantages : configurable thread pool, request priority, caching, request cancel. AsyncTask is no more needed and this is a good new as AsyncTask is known for its memory leak issues. The good thing about Volley is that … Continue reading

Android – Google Cloud Messaging

Google Cloud Messaging for Android (GCM) is a service that allows you to send data from your server to your users’ Android-powered device, and also to receive messages from devices on the same connection. The GCM service handles all aspects of queueing of messages and delivery to the target Android application running on the target device. GCM is completely free no matter how big your messaging needs are, and there are no quotas. The following diagram is illustrating the overview … Continue reading

How Global Positioning System (GPS) Work

Image

GPS Services

GPS satellites provide service to civilian and military users. The civilian service is freely available to all users on a continuous, worldwide basis. The military service is available to U.S. and allied armed forces as well as approved Government agencies.

The Global Positioning System is a U.S.-owned utility that provides users with positioning, navigation, and timing services. When people talk about “a GPS,” they usually mean a GPS receiver. The U.S. military developed and implemented this satellite network as a military navigation system, but soon opened it up to everybody else. They develops, maintains, and operates the space and control segments.

This system consists of three segments: the space segment, the control segment, and the user segment.

Space Segment :

The Global Positioning System (GPS) is actually a constellation of 27 Earth-orbiting satellite (24 in operation and three extras in case one fails).  Active satellite transmit one way signal that give the current satellite position and time. Each of these 3,000- to 4,000-pound solar-powered satellites circles the globe at about 12,000 miles (19,300 km), making two complete rotations every day.

The satellites in the GPS constellation are arranged into six equally-spaced orbital planes surrounding the Earth. Each plane contains four “slots” occupied by baseline satellites. This 24-slot arrangement ensures there are at least four satellites in view from virtually any point on the planet.

satellite_orbits

Control Segment :

The control segment consists of worldwide monitor and control stations that maintain the satellites in their proper orbit through occasional command and adjust the satellite clocks, It tracks the GPS satellites, upload updated navigational data and maintains health and status of the satellite.

User Segment :

The user segment consists of the GPS receiver equipment, which receives the signals from the GPS satellites and uses the transmitted information to calculate the user’s three dimensional position and time.

A GPS receiver’s job is to locate four or more of these satellites, figure out the distanc­e to each, and use this information to deduce its own location. This operation is based on a simple mathematical principle called trilateration.

In order to make this simple calculation, then, the GPS receiver has to know two things:

  • The location of at least three satellites above you
  • The distance between you and each of those satellites

The GPS receiver figures both of these things out by analyzing high-frequency, low-power radio signals from the GPS satellites. Better units have multiple receivers, so they can pick up signals from several satellites simultaneously.

Here is a visualization how a GPS receiver find out his location.

http://www.youtube.com/watch?v=0n0T992ccik

With 2 satellite :

gps_posb_1

With 3 Satellite.

gps_posb_3

 

Question for test your knowledge :

GPS satellites continuously track and record the movements of every GPS user.

True or false?

Selenium IDE – parameterization

For parameterization you need to create a JS file. For eg. Js file contains   var username=new Array(“parameterization1@mail.com”,”parameterization2@mail.com”); var password=new Array(“parameterization1″,”parameterization2″); Now open Selenium IDE and provide the path of this JS file in Selenium Core Extensions in Options of Selenium IDE. Restart Selenium IDE after providing the above path, there should not be any error on next launch of Selenium IDE. Now copy and paste the below code in Source Window of IDE. <tr> <td>store</td> <td>0</td> <td>looptimes</td> </tr> <tr> … Continue reading

Curl does not work on Window Vista 64-bit

Scenario – You have enabled curl in your php.ini file of your wamp server, still you are getting mesaages to enable curl or an curl exception. Solution: get curl.dll from this url http://www.anindya.com/php-5-4-3-and-php-5-3-13-x64-64-bit-for-windows/  under Fixed curl extensions: and replace it with old one.

Why estimation is important

Though it is best to size the tasks instead of estimating them, it requires some getting used to before one shifts to sizing. So let us keep it aside for the moment. The first impulse when an idea is conceived or a project requirement received is to start coding. Unfortunately there are no rewards for starting early the rewards are in providing Clients a valuable solution at the earliest.With the finish / “Done” depending on collaboration with other team members … Continue reading

Security Testing – Test Cases.

These are some of the test cases which should be taken care of while doing Security testing for an Windows based project”: Bookmarked web page should not be accessible without login to the system. Verify that system should restrict you to download the file without sign in on the system. Verify that previous accessed pages should not be accessible after log out i.e. Sign out and then press the Back button to access the page accessed before. Check for valid … Continue reading