An M4A file (MPEG-4 Part 14) is an audio file developed for QuickTime and other MP4 players. Essentially, an M4A file is the same as an MP4 or MOV file, but specifically defines MPEG features and stores audio rather than video. M4A files contain file compression algorithms that allow them to be much smaller than other audio formats, such as MP3 and WAV, while maintaining high quality. They are specifically designed to be used with QuickTime and other Apple products, but a wide variety of media players can also use Read More

Groups are containers that contain user and computer objects within them as members. When security permissions are set for a group in the Access Control List on a resource, all members of that group receive those permissions. Domain Groups enable centralized administration in a domain. All domain groups are created on a domain controller. In a domain, Active Directory provides support for different types of groups and group scopes. The group type determines the type of task managed with the group. The group scope determines whether the group can have Read More

Facebook is a great way to connect with others. Although Facebook users enjoy connecting with others, they may not want some of their contacts to see the friends they have made or the contacts on their account. In order to make friends invisible on a Facebook profile page, privacy settings must be adjusted. This can be achieved by the following process: Log on to Facebook. Select the “Account” tab from the upper right corner of the page. Select “Privacy Settings” from the drop down list. This leads to the ‘Choose Read More

YouTube is one of the most popular video-sharing websites on the Internet. The company was founded in 2005 and acquired by Google in 2007. YouTube is focused on hosting user-generated content such as video blogs, video and movie clips and original content. YouTube also hosts material from major media companies such as BBC, CBS, and VEVO. File Formats Supported by YouTube YouTube states they can accept most video file formats. However, some formats are preferred. The following are a few of their most popular file types: WebM Files .MPEG4, 3GPP, Read More

Angular acceleration is the rate of change of a body’s angular velocity compared to time. It is considered a vector quantity since it has a direction and magnitude. Angular acceleration is similar to linear acceleration except that it travels on an arc. Scientifically, it is equal to (final angular velocity – initial angular velocity) / time. A body’s angular velocity is the rate of change of angular distance with respect to time and acceleration is the rate of this change over the same time frame. How is Angular Acceleration Measured? Read More

DVB-RCS stands for Digital Video Broadcast – Return Channel Satellite. DVB-RCS is part of the DVB standards for satellite communication, DVB-S and DVB-S2. The purpose of DVB-RCS is to provide a return channel to enable Internet and other data services over satellite. ViaSat’s LinkStar system is one of the VSAT satellite broadband implementations which support DVB-RCS. The DVB standards are maintained by the DVB Project, which is an industry-led consortium of over 260 broadcasters, manufacturers, network operators, software developers, regulatory bodies and others in over 35 countries. DVB-RCS is officially Read More

Management Tools for Administering Exchange Server 2003 The Active Directory Users and Computers Management Console The Active Directory Users and Computers snap-in is extended to support the management of mailbox configurations and settings. The Active Directory Users and Computers management console is the central tool used for creating and managing user account and computer account objects and configuration settings in Windows domains. Users can apply different permissions to different Exchange server objects. Permissions can be assigned at the Exchange organization level and at the Administrative Group level: Exchange Full Administrator Read More

A MAC address is an address that exists on Layer 2 of the OSI Model. Layer 2 of the OSI model is the Data Link Layer. The Data Link Layer consists of two sublayers, the Media Access Control (MAC) layer and the Logical Link Control (LLC) layer. The MAC sublayer controls how a network node gains access to the data and permission to transmit it. MAC addresses are globally unique and are written into hardware when manufactured. For this reason, MAC addresses are sometimes called Burned In Addresses (BIA). After Read More

Mondex is a specific smart card which was developed by England’s National Westminster Bank in 1990. Its design was intended to serve as electronic cash or a virtual electronic wallet. Any amount of money can be transferred to the Mondex smart card. MasterCard international bought controlling interest in the resulting firm, Mondex International, in 1997 joining such companies as AT&T and Wells Fargo in the pursuit of this advanced technology. The design of a Mondex smart card allows end users to transfer funds electronically onto the card and then utilize Read More

The term driver refers to files that permit hardware and software programs to interface with the Windows Operating System (OS). All hardware components require a driver file in order to work properly with the Windows XP OS unless they are compatible with one of the generic driver files included with the OS. These files are normally stored on the computer’s hard drive. However, a prudent computer owner will make a backup copy of the drivers on the Windows XP OS, to make recovery from malware infection or other catastrophic computer Read More