Using Firewalls To Prevent Unauthorized Access The method, by which you can physically secure the network, is through the usage of firewalls. While firewalls provide some level of physical security, you should bear in mind that firewalls are just barriers which make it difficult for intruders to attack the network. Firewalls are categorized as follows: Network firewalls: These firewalls monitor traffic entering and exiting the network, in an attempt to protect the perimeter network. Software based Microsoft Internet Security and Acceleration (ISA) Server and the hardware based Nortel Networks Alteon Read More

Status Messages Overview All SMS 2.0 components and services generate status messages as they perform their various functions. These status messages illustrate the movement of processing activity of the SMS site systems and clients. The status messages are automatically summarized for viewing through status summarizers and filtered through status filters. A status message can have one of the following severity levels: Informational status messages: These messages merely inform on events such as a component starting, and a task completing. Warning status messages: These messages point out potential problems that can Read More

X.509 is an ITU-T (ITU Telecommunication Standardization Sector) standard for PKI (Public Key Infrastructure) in cryptography, which, amongst many other things, defines specific formats for PKC (Public Key Certificates) and the algorithm that verifies a given certificate path is valid under a give PKI (called the certification path validation algorithm). X.509 History X.509 began in association with the X.500 standard in 1988 (Version 1) and it assumed a hierarchical system of certification authorities for issuing of certificates, quite contrary to the then existing web trust models – such as PGP Read More

Holograms are three-dimensional images produced through photographic projection. Unlike 3-D graphics or Virtual Reality or Augmented reality displays where the image is projected in a two-dimensional surface and where the illusion of depth is applied, holograms are truly three-dimensional images that do not need special viewing equipments. The first hologram was created in 1947 by Dennis Gabor while doing research on improving the resolution of electron microscopes. The lasers needed for displaying and creating these holograms, however, did not exist until 1960. Categories of Holograms Holograms can be categorized into Read More

PROM stands for Programmable Read-Only Memory. It was invented by Wen Tsing Chow in 1956. Unlike a ROM chip, a PROM chip comes from the manufacturers devoid of any programming. Programming is done by the end user or the makers of electronic devices which require a permanent data storage device. Since it is cheaper than a ROM chip, it is also useful for making experimental programming test runs. Successful programming can later on be applied to a ROM chip at manufacture. A PROM chip can only be programmed with the Read More

It is quite important to know which version of Java is presently installed on your computer. This might specially come handy to those who are developing applications and software on the Java platform. Using an outdated version of Java may hinder your Java development or even render web pages inappropriately in your browser. Mentioned below are few straightforward ways to check which version of Java is installed on your computer. Command Line Open Command Prompt and type in the following command: java -version Upon successful execution, the command will output Read More

Flops are a special acronym that describes a unit of measurement known as "FLoating point Operations Per Second". This measurement is extremely important in determining the amount of operations which could be handled by computer technologies. In today's computing, gigaflops of data can be handled by different hardware options. A gigaflop is a measurement in terms of one billion floating point operations per second. This is useful for modern day computers because they tend to process so many operations in a given second. The fastest modern supercomputers are capable of performing at the petaflop level, Read More

For the past two decades, lasers have been used to measure distance without having to physically touch the area or things being measured. Laser measurement is capable of very precise and quick distance measurements. Lasers have been used in military targeting, criminal investigations, and sports. As research has progressed, the size of laser measuring devices has decreased, while computer power capable of interpreting and using measurement data has increased. What Techniques Do Lasers Use to Measure Distance? A laser uses several techniques to measure distance. They include: Time of Flight Read More

On-line books On-line books are a type of eBook that can be accessed and read via the Internet. Online books are available as free and paid versions. They are different from traditional e-books as they can be read online. Before the advent of the Internet, e-books were in CD format which had to be inserted  into the computer to be accessed and read. Apart from web sites, there are hardware devices known as eBook readers, which work with software services to provide online e-book access. E-books can now be read Read More

The Types of Commands used to Manage IIS from the Command Line The types of commands that manage IIS from the command line are: IISReset, Windows Management Instrumentation (WMI) scripts, Active Directory Services Interface (ADSI), and the standard Windows commands and Support Tools utilities. IISReset Command-line Utility IISReset is a command-line utility that has been in existence from IIS 5 that can be used to stop IIS, restart IIS, and reboot the IIS server. Typical reasons for restarting IIS are: When problematic ASP.NET and ASP applications exist and resource leaks Read More