IBM Worklight

IBM Worklight V5 provides an open, comprehensive, advanced platform for developing mobile enterprise applications for smartphones and tablets. As a complete, open standards-based platform that leverages technologies such as HTML5, CSS3, and Apache Cordova, Worklight helps organizations of all sizes efficiently develop, connect, run, and manage HTML5, hybrid, and native mobile applications. 

Worklight supports all stages of the mobile development lifecycle, including application building, deployment, execution, and management, and provides tools to help at each step along the way.

Leveraging standards-based technologies and tools, Worklight ships with a comprehensive development environment, mobile-optimized middleware, and an integrated management and analytics console, supported by a variety of security mechanisms. Worklight enables the creation of rich, cross-platform applications without the use of code translation, proprietary interpreters, or unpopular scripting languages. It also reduces time to market, development cost, and overall complexity, enabling you to provide a better user experience across a broad array of mobile devices.

Types of Server

Server

A server is the machine that runs data management software that has been designed for server functionality. A server has operating system software, data management software and a portion of the network software.

File server

File servers manage a work group’s applications and data files, so that they may be shared by the group. File servers are very I/O oriented. They pull large amounts of data off their storage subsystems and pass the data over the network. When the data from the file is requested, a file server transmit all records from the file.

Web server

A web server is a computer system that delivers web pages. Every web server has an IP address and possibly a domain name.  

Group Server

A Groupware server is a software designed to enable users to collaborate, regardless of location through the internet or a corporate intranet and to work together in a virtual atmosphere.

Application server

Application server, which provides specific application services to an application. Application servers are the type of middleware, which occupy a large chunk of computing territory between database servers and end users.

Database servers

Database servers, which provide database storage and data sharing with other computers in the network. Database servers more and store data records or databases over corporate networks and across the internet.

Examples of famous algorithms

·         Constructions of Euclid

·         Newton's root finding

·         Fast Fourier Transform

·         Compression (Huffman, Lempel-Ziv, GIF, MPEG)

·         DES, RSA encryption

·         Simplex algorithm for linear programming

·         Shortest Path Algorithms (Dijkstra, Bellman-Ford)

·         Error correcting codes (CDs, DVDs)

·         TCP congestion control, IP routing

·         Pattern matching (Genomics)

·         Search Engines

Categories of E-Commerce

1. Business-to-consumer (B2C) occurs when businesses sell finished products or services to individual consumers.
2. Business-to-business (B2B) occurs when businesses sell unfinished materials, products, or services to other businesses.
3. Consumer-to-consumer (C2C) occurs when individuals buy and sell items among themselves.  Online auctions such as eBay would be perfect examples.
4. Business-to-government (B2G) includes business transactions with government agencies.  Businesses pay taxes, file reports, or sell goods and services to government agencies.
5. government-to-government (G2G).  This includes transactions between one government agency and another.

Disadvantages of C

1. C is designed for professional users.
2. C was not able to automatic checking compare other languages.
3. C does not support modern concept like OOP’s and multithreading.

Advantages of C

1. C is a small , efficient ,powerful and flexible language
2. C is close to computer H/W (architecture).
3. C is standardized, making it more portable compare to other languages.
4. It contains libraries.
5. Many other languages borrow from Csyntax for ex: Java, java script, perl.
6. UNIX was written in C.

Features of C Language

1. C language is the structured programming language because it has some standards.
2. Code reusability means we can use the code from environment to other environment.
3. Built in type float, int etc expressions, operators.
4. Syntax for decision control.
5. It has some libraries which pre is defined.(preprocessors).
6. File organization (.c, .cpp etc)

UNDERSTANDING HTML

A web page is a plain text file encoded using Hypertext Markup Language (HTML).

HTML means word by word:

v     Hypertext – Text that helps to jump from document to document.

v     Markup – Tags that apply layout and formatting conventions to plain text

v     Language – A reference to the fact that HTML is considered as a programming language.

Pyramid Program in JAVA

public class Pyramid {

       public static void main(String[] args) {

      

              int n=3;

              for (int i = 1; i <= n; i++)

        {

              for (int j = 0; j < (n - i); j++)

                    System.out.print(" ");

              for (int j = 1; j <= i; j++)

                    System.out.print("*");

              for (int k = 1; k < i; k++)

                    System.out.print("*");

              System.out.println();

        }

        for (int i = n - 1; i >= 1; i--)

        {

              for (int j = 0; j < (n - i); j++)

                    System.out.print(" ");

              for (int j = 1; j <= i; j++)

                    System.out.print("*");

              for (int k = 1; k < i; k++)

                  System.out.print("*");

              System.out.println();

        }

        System.out.println();

       }

}

Output:

  *

 ***

*****

 ***

  *

Differences between ASP.NET and Client-Side Technologies

Client-side refers to the browser and the machine running the browser. Server-side on the other hand refers to a Web server.

Client-Side Scripting

Javascript and VBScript and generally used for Client-side scripting. Client-side scripting executes in the browser after the page is loaded. Using client-side scripting you can add some cool features to your page. Both, HTML and the script are together in the same file and the script is download as part of the page which anyone can view. A client-side script runs only on a browser that supports scripting and specifically the scripting language that is used. Since the script is in the same file as the HTML and as it executes on the machine you use, the page may take longer time to download.

Server-Side Scripting

ASP.NET is purely server-side technology. ASP.NET code executes on the server before it is sent to the browser. The code that is sent back to the browser is pure HTML and not ASP.NET code. Like client-side scripting, ASP.NET code is similar in a way that it allows you to write your code alongside HTML. Unlike client-side scripting, ASP.NET code is executed on the server and not in the browser. The script that you write alongside your HTML is not sent back to the browser and that prevents others from stealing the code you developed. 

Computer Science General Knowledge - Part III

GSM

• Short for Global System for Mobile Communications, one of the leading digital cellular systems. GSM uses narrowband TDMA, which allows eight simultaneous calls on the same radio frequency.
• GSM was first introduced in 1991. As of the end of 1997, GSM service was available in more than 100 countries and has become the de facto standard in Europe and Asia.

E-Mail Spoofing

• Forging an e-mail header to make it appear as if it came from somewhere or someone other than the actual source. The main protocol that is used when sending e-mail -- SMTP -- does not include a way to authenticate.
• There is an SMTP service extension (RFC 2554) that allows an SMTP client to negotiate a security level with a mail server.
• But if this precaution is not taken anyone with the know-how can connect to the server and use it to send spoofed messages by altering the header information.

BLOB

• Short for binary large object, a collection of binary data stored as a single entity in a database management systems (DBMS).
•  BLOBs are used primarily to hold multimedia objects such as images, videos, and sound, though they can also be used to store programs or even fragments of code. Not all DBMSs support BLOBs.

AODV

• Short for Ad Hoc On-Demand Distance Vector, a routing protocol for ad hoc mobile networks with large numbers of mobile nodes.
• The protocol's algorithm creates routes between nodes only when the routes are requested by the source nodes, giving the network the flexibility to allow nodes to enter and leave the network at will.
• Routes remain active only as long as data packets are traveling along the paths from the source to the destination. When the source stops sending packets, the path will time out and close.

4G

• Short for fourth generation, 4G is an ITU specification that is currently being developed for broadband mobile capabilities. 4G technologies would enable IP-based voice, data and streaming multimedia at higher speeds and offer at least 100 Mbit/s with high mobility and up to 1GBit/s with low mobility (nomadic).
• 4G is an IP-based and packet-switched evolution of 3G technologies (such as WCDMA, HSDPA, CDMA2000 and EVDO) that uses voice communications. A number of technologies considered to be 4G standards include Long Term Evolution (LTE), Ultra Mobile Broadband (UMB) and the IEEE 802.16 (WiMax) standard.
• While 3G is defined by ITU as IMT-2000, IMT-Advanced is being studied by ITU as 4G. IMT is now used as the generic name for 3G and 4G.

Data Warehouse

• Abbreviated DW, a collection of data designed to support management decision making. Data warehouses contain a wide variety of data that present a coherent picture of business conditions at a single point in time.
• Development of a data warehouse includes development of systems to extract data from operating systems plus installation of a warehouse database system that provides managers flexible access to the data.
• The term data warehousing generally refers to the combination of many different databases across an entire enterprise. Contrast with data mart.

iHTML

• Short for inline HTML, an advanced server-side scripting/programming language that functions as an extension to HTML, allowing the customization of dynamic Web sites that depend on interaction with databases.
•  iHTML eliminates the need for Javascript or CGI programs as it provides the same functionality.

Dual-Core

• Dual-core refers to a CPU that includes two complete execution cores per physical processor. It has combined two processors and their caches and cache controllers onto a single integrated circuit (silicon chip).
• Dual-core processors are well-suited for multitasking environments because there are two complete execution cores instead of one, each with an independent interface to the frontside bus. Since each core has its own cache, the operating system has sufficient resources to handle most compute intensive tasks in parallel.
• Multi-core is similar to dual-core in that it is an expansion to the dual-core technology which allows for more than two separate processors.

Windows CE

• A version of the Windows operating system designed for small devices such as personal digital assistants (PDAs) (or Handheld PCs in the Microsoft vernacular).
• The Windows CE graphical user interface (GUI) is very similar to Windows 95 so devices running Windows CE should be easy to operate for anyone familiar with Windows 95.

Pervasive Computing

• The idea that technology is moving beyond the personal computer to everyday devices with embedded technology and connectivity as computing devices become progressively smaller and more powerful. Also called ubiquitous computing, pervasive computing is the result of computer technology advancing at exponential speeds -- a trend toward all man-made and some natural products having hardware and software.
• Pervasive computing goes beyond the realm of personal computers: it is the idea that almost any device, from clothing to tools to appliances to cars to homes to the human body to your coffee mug, can be imbedded with chips to connect the device to an infinite network of other devices.
• The goal of pervasive computing, which combines current network technologies with wireless computing, voice recognition, Internet capability and artificial intelligence, is to create an environment where the connectivity of devices is embedded in such a way that the connectivity is unobtrusive and always available.

Tablet Pc

• A type of notebook computer that has an LCD screen on which the user can write using a special-purpose pen, or stylus. The handwriting is digitized and can be converted to standard text through handwriting recognition, or it can remain as handwritten text.
• The tablet PC relies on digital ink technology, where a digitizer is laid under or over an LCD screen to create an electromagnetic field that can capture the movement of the special-purpose pen and record the movement on the LCD screen. The effect is like writing on paper with liquid ink.
• The Microsoft Windows operating system designed for tablet PC technology.

MPEG-4

• A graphics and video lossy compression algorithm standard that is based on MPEG-1 and MPEG-2 and Apple QuickTime technology.
• Wavelet-based MPEG-4 files are smaller than JPEG or QuickTime files, so they are designed to transmit video and images over a narrower bandwidth and can mix video with text, graphics and 2-D and 3-D animation layers.
• Wavelet technology can compress color images at rates of 20:1 up to 300:1 and grayscale images at 20:1 to 50:1. MPEG-4 was standardized in October 1998 in the ISO/IEC document 14496.

Smart Card

• A small electronic device about the size of a credit card that contains electronic memory, and possibly an embedded integrated circuit (IC). Smart cards containing an IC are sometimes called Integrated Circuit Cards (ICCs).
• Smart cards are used for a variety of purposes, including:

o          Storing a patient's medical records

o          Storing digital cash

o          Generating network IDs (similar to a token)

• To use a smart card, either to pull information from it or add data to it, you need a smart card reader, a small device into which you insert the smart card.

GPS

• Short for Global Positioning System, a worldwide MEO satellite navigational system formed by 24 satellites orbiting the earth and their corresponding receivers on the earth. The satellites orbit the earth at approximately 12,000 miles above the surface and make two complete orbits every 24 hours.
• GPS was developed and is operated by the U.S. Department of Defense. It was originally called NAVSTAR (Navigation System with Timing and Ranging).
• GPS has applications beyond navigation and location determination. GPS can be used for cartography, forestry, mineral exploration, wildlife habitation management, monitoring the movement of people and things and bringing precise timing to the world.

JAR

• Short for Java Archive, a file format used to bundle all components required by a Java applet. JAR files simplify the downloading of applets since all the components (.class files, images, sounds, etc.) can be packaged into a single file.
•  In addition, JAR supports data compression, which further decreases download times.
• By convention, JAR files end with a .jar extension.

Data Migration

• The process of translating data from one format to another. Data migration is necessary when an organization decides to use a new computing systems or database management system that is incompatible with the current system.
• Typically, data migration is performed by a set of customized programs or scripts that automatically transfer the data.
• The process of moving data from one storage device to another. In this context, data migration is the same as Hierarchical Storage Management (HSM).

T-SQL

• Short for Transaction-SQL, an extended form of SQL that adds declared variables, transaction control, error and exception handling and row processing to SQL??s existing functions.
• Microsoft SQL and Sybase both support T-SQL statements. Up until version 4.2, the Microsoft SQL Server and Sybase relational database were developed together to work together.
• It should be noted that Sybase refers to its statements as T-SQL while Microsoft refers to its statements as Transaction-SQL.

DSN

• Short for Data Source Name. Data Source Name provides connectivity to a database through an ODBC driver. The DSN contains database name, directory, database driver, UserID, password, and other information. Once you create a DSN for a particular database, you can use the DSN in an application to call information from the database.
• DSN is often used by Active Server Pages (ASP) and Visual Basic programs when a query to a database is necessary to retrieve information.
• There is also what is known as a "DSN-less connection." Instead of using a DSN to connect to a database, the developer specifies the necessary information right in the application. With a DSN-less connection the developer is free to use connection standards other than ODBC, such as OLE DB. 

What is PHP?

• PHP stands for PHP: Hypertext Preprocessor
• PHP is a server-side scripting language, like ASP
• PHP scripts are executed on the server
• PHP supports many databases (MySQL, Informix, Oracle, Sybase, Solid, PostgreSQL, Generic ODBC, etc.)
• PHP is an open source software
• PHP is free to download and use

Why PHP?

• PHP runs on different platforms (Windows, Linux, Unix, etc.)
• PHP is compatible with almost all servers used today (Apache, IIS, etc.)
• PHP is FREE to download from the official PHP resource: www.php.net
• PHP is easy to learn and runs efficiently on the server side 

Advantage of ASP.NET

• ASP.NET drastically reduces the amount of code required to build large applications
• ASP.NET makes development simpler and easier to maintain with an event-driven, server-side programming model
• ASP.NET pages are easy to write and maintain because the source code and HTML are together
• The source code is executed on the server. The pages have lots of power and flexibility by this approach
• The source code is compiled the first time the page is requested. Execution is fast as the Web Server compiles the page the first time it is requested. The server saves the compiled version of the page for use next time the page is requested
• The HTML produced by the ASP.NET page is sent back to the browser. The application source code you write is not sent and is not easily stolen
• ASP.NET makes for easy deployment. There is no need to register components because the configuration information is built-in
• The Web server continuously monitors the pages, components and applications running on it. If it notices memory leaks, infinite loops, other illegal software or activities, it seamlessly kills those activities and restarts itself
• ASP.NET validates information (validation controls) entered by the user without writing a single line of code
• ASP.NET easily works with ADO .NET using data-binding and page formatting features
• ASP.NET applications run faster and counters large volumes of users without performance problems 

OpenStack: The Open Source Cloud Operating System

OpenStack is a cloud operating system that controls large pools of compute, storage, and networking resources throughout a datacenter, all managed through a dashboard that gives administrators control while empowering their users to provision resources through a web interface.

 

 

 

Computer Science General Knowledge - Part II

NANO COMPUTING

• Nanotechnology is a group of sciences dealing with nanometre-scale devices and particles ➢One nanometre is 0.000000001 of a metre.
• Nanometre-scale usually indicates measurements up to a few hundred nanometers.
• Nanocomputing deals with nanometre-scale computers.

BETA TEST

• A test for a computer product prior to commercial release.
• Beta testing is the last stage of testing, and normally can involve sending the product to beta test sites outside the company for real-world exposure or offering the product for a free trial download over the Internet.
•  Beta testing is often preceded by a round of testing called alpha testing.

AJAX

• Short for Asynchronous JavaScript and XML, it is a term that describes a new approach to using a number of existing technologies together, including the following: HTML or XHTML, Cascading Style Sheets, JavaScript, the Document Object Model, XML, XSLT, and the XMLHttpRequest object.
• When these technologies are combined in the Ajax model, Web applications are able to make quick, incremental updates to the user interface without reloading the entire browser page.

 3G

• 3G is an ITU specification for the third generation (analog cellular was the first generation, digital PCS the second) of mobile communications technology.
• 3G promises increased bandwidth, up to 384 Kbps when a device is stationary or moving at pedestrian speed, 128 Kbps in a car, and 2 Mbps in fixed applications.
• 3G will work over wireless air interfaces such as GSM, TDMA, and CDMA. The new EDGE air interface has been developed specifically to meet the bandwidth needs of 3G.

 CAD/CAM

• Acronym for computer-aided design/computer-aided manufacturing, computer systems used to design and manufacture products.
• The term CAD/CAM implies that an engineer can use the system both for designing a product and for controlling manufacturing processes.
• For example, once a design has been produced with the CAD component, the design itself can control the machines that construct the part.

Data Mining

• A class of database applications that look for hidden patterns in a group of data that can be used to predict future behavior. For example, data mining software can help retail companies find customers with common interests.
• The term is commonly misused to describe software that presents data in new ways. True data mining software doesn't just change the presentation, but actually discovers previously unknown relationships among the data.
• Data mining is popular in the science and mathematical fields but also is utilized increasingly by marketers trying to distill useful consumer data from Web sites.
• Visit eCRM Guide to learn more about data mining and enterprise applications.

GPRS

• Short for General Packet Radio Service, a standard for wireless communications which runs at speeds up to 115 kilobits per second, compared with current GSM (Global System for Mobile Communications) systems' 9.6 kilobits.
• GPRS, which supports a wide range of bandwidths, is an efficient use of limited bandwidth and is particularly suited for sending and receiving small bursts of data, such as e-mail and Web browsing, as well as large volumes of data.

SPYWARE

• Spyware applications are typically bundled as a hidden component of freeware or shareware programs that can be downloaded from the Internet. Spyware can also gather information about e-mail addresses and even passwords and credit card numbers.
• Spyware is similar to a Trojan horse in that users unwittingly install the product when they install something else.
•  A common way to become a victim of spyware is to download certain peer-to-peer file swapping products that are available today.
• Licensing agreements that accompany software downloads sometimes warn the user that a spyware program will be installed along with the requested software, but the licensing agreements may not always be read completely because the notice of a spyware installation is often couched in obtuse, hard-to-read legal disclaimers.

ERP

• Short for enterprise resource planning, a business management system that integrates all facets of the business, including planning, manufacturing, sales, and marketing..
• As the ERP methodology has become more popular, software applications have emerged to help business managers implement ERP in business activities such as inventory control, order tracking, customer service, finance and human resources.

Wi-Fi

• The Wi-Fi Alliance, the organization that owns the Wi-Fi (registered trademark) term specifically defines Wi-Fi as any "wireless local area network (WLAN) products that are based on the Institute of Electrical and Electronics Engineers' (IEEE) 802.11 standards."
• Wi-Fi works with no physical wired connection between sender and receiver by using radio frequency (RF) technology.
• A common misconception is that the term Wi-Fi is short for "wireless fidelity," however this is not the case. Wi-Fi is simply a trademarked term meaning IEEE 802.11x.

IVR

• Short for interactive voice response, a telephony technology in which someone uses a touch-tone telephone to interact with a database to acquire information from or enter data into the database.
• IVR technology does not require human interaction over the telephone as the user's interaction with the database is predetermined by what the IVR system will allow the user access to.
• IVR technology is also used to gather information, as in the case of telephone surveys in which the user is prompted to answer questions by pushing the numbers on a touch-tone telephone.

 Image Map

• A single graphic image containing more than one hot spot. For example, imagine a graphic of a bowl of fruit. When you click on a banana, the system displays the number of calories in a banana and when you click on an apple, it displays the number of calories in an apple.
• Image maps are used extensively on the World Wide Web. Each hot spot in a Web image map takes you to a different Web page.
• Image map is sometimes spelled as one word: imagemap.

 GML

• Short for Geography Markup Language, an XML-based language for encoding geographic information in order to be stored and transported over the Internet.
• Developed by the OpenGIS Consortium, GML defines both the geometry and properties of objects that comprise geographic information.
• GML is a practical application for transferring cartographic information over the Web. Instead of transmitting a GIF or JPG map, GML allows the data to be controlled on the browser end by the user who receives geometries and geographic features and customizes how the data is to be displayed. Geographic data in GML can be sent to any device with an XML interface.

HyperCard

• A hypertext programming environment for the Macintosh introduced by Apple in 1987. The HyperCard model consists of cards, and collections of cards, called stacks
• Each object in a HyperCard system -- stack, card, text field, button, or background -- can have a script associated with it. A script is a set of instructions that specify what actions should take place when a user selects an object with the mouse or when some other event occurs.
• Writing HyperCard applications is known as authoring.

 E-Cycle

• A term used to describe the practice of recycling computers, computer components and other electronics through reusing or donating them until the end of their lifecycle.
• E-cycling encourages people to reduce, reuse and recycle rather than dispose of these items prematurely when upgrading to newer products.
• At the end of the electronics' life, people are then encouraged to dispose of the item at an electronics recycler to keep the electronics out of landfills and reduce the amount of electronic waste. May also be written as eCycle or ecycle.

FIREWALL

• A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both.
•  Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets.
• All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.