Not Provided vs. Not Set in Google Analytics

What is the difference between Not Provided and Not Set under the keywords section in Google Analytics?

Answer:

Not Provided occurs when a user is browsing on an encrypted URL at Google.com. If you are logged in to your Google+ account, you will automatically be on https://. This means the more users that use Google+, the more you will not be able to see what keywords brought them to your website.

Not Set is simply a referral or direct visit with no keywords that are allowed to be passed. Sometimes a user can search from their browser and end up on the site and this may propagate (Not Set).

Tip:

You can click (not provided) and view the landing pages as a secondary dimension to at least figure out what pages are being viewed the most. You could also compare this to the known organic keyword traffic and attribute a estimated percentage in distribution to each known organic keyword.

Click to Enlarge - You could also do unique page views for increased accuracy to attribute to other relateed keywords for each individual content page.

ACL Definition, What is ACL

The Access Control list is the list is a data structure, usually a table, containing entries that specify individual user or group rights to specific system objects, such as a program, a process, or a file. These entries are known as access control entries (ACE) in the Microsoft Windows and OpenVMS operating systems. Each accessible object contains an identifier to its ACL. The privileges or permissions determine specific access rights, such as whether a user can read from, write to or execute an object. In some implementations an ACE can control whether or not a user, or group of users, may alter the ACL on an object.

The ACL is a concept with several different implementations in various operating systems, although there is a POSIX "standard" (the POSIX security drafts, .1e and .2c, were withdrawn when it became clear their scope was too wide and the work would not complete, but the well-developed parts defining ACLs have been widely implemented and are known as "POSIX ACLs").

ACL implementations can be quite complex. ACLs can apply to objects, directories and other containers, and for the objects and the containers created within this container. ACLs cannot implement all of the security measures that one might wish to have on all systems, and a fine-grained capability-based access control system may be a better approach, with the authority transferred from the objects being accessed to the objects seeking access — allowing for much finer-grained control.

In networking, the term Access Control List (ACL) refers to a list of service ports or (network) daemon names that are available on a host, each with a list of hosts and/or networks permitted to use the service. Both individual servers as well as routers can have network ACLs. Access control lists can generally be configured to control both inbound and outbound traffic, and in this context they are similar to firewalls.

ADP Definition, What is ADP

ADP or Automatic Data Processing, Inc. (NYSE: ADP) is the largest provider of computerized transaction processing and information-based solutions serving more than 570,000 clients worldwide. ADP Employer Services provides human resources, payroll and benefits administration solutions for companies of all sizes throughout the U.S. and in major markets around the world. ADP Dealer Services provides integrated dealer management system (DMS) solutions to automotive, heavy truck, motorcycle, marine and RV dealers and manufacturers in North America.

History of Automatic Data Processing

ADP was founded in 1949 by Henry Taub in Paterson, New Jersey as Automatic Payrolls, Inc. The first ADP office, above Grinker's Ice Cream shop, processed payroll manually with a bookkeeping machine, addressograph equipment, calculators and comptometers. The company's first account was New Era Dye and Finishing in Fair Lawn, New Jersey. With the introduction of punch card machines, mainframe computers and check printing machines, Automatic Payrolls became Automatic Data Processing in 1958.

ADP became a public company in 1961, with an initial stock price of $3. In the next year, Brokerage Services division was developed to serve the high volume transaction needs of major stock brokerages on Wall Street. The company proceeded to offer Dealer Services to automotive dealers to handle inventory and accounting transactions. In 1974, ADP extended into the international market with an office in The Netherlands, and later in the decade added Claims Services.

Today ADP employs more than 42,000 associates globally providing business solutions for more than 570,000 companies of all sizes � small, mid-market and enterprise.
Business Units

ADP Employer Services

The Employer Services business unit is the oldest, largest and most profitable of ADP's divisions. It includes payroll processing, HR outsourcing, 401(k)/Retirement Services, Professional Employer Organization (PEO), Time and Labor Management, Tax and Compliance Management, Benefits Administration, Screening and Selection Services, and Administrative Service Offerings (ASO). ADP's payroll services are so widespread that one in six Americans have their paychecks processed by the company.

ADP Dealer Services

In 1972, Dealer Services was created for automobile dealer front end management, business office, parts and service departments.

ADP Claims Services

ADP's Claims Services was created to assist insurance companies with property and casualty claims, automotive recycling, and collision repair in 1979. This division was sold off because its growth potential was far less than the other divisions of the company.

ADP Brokerage Services

This division of ADP was created in 1962 to service stock brokerages. Oppenheimer & Co. became the first client, averaging 300 trades per day. By 1999, ADP was processing over a million trades in a day. This business was spun off in 2007 into a company called Broadridge Financial Solutions (NYSE: BR), removing about $2 billion from ADP's total yearly revenue.

ADP References

ADP Directors and Corporate Officers
Jeffrey R. Yost (2005). The Computer Industry. Greenwood Press. ISBN 0313328447.
Edward J. Kanarkowski (1999). ADP 50th Anniversary Book. ADP.
College Savings Boosted by ADP's 529 Payroll Deduction Program
ADP Completes Spin-off of Brokerage Services Group Business

Access Privileges Definition, What is Access Privileges

Access Privileges is the extent to which a user may operate a system resource on a network or a file server.In many cases, permission to access a server, view its contents and modify or create files is limited by the network's system administrator in order to maintain security.

Privileges in Computer Science

A privilege in a computer system is a permission to perform an action. Examples of various privileges include the ability to create a file in a directory, or to read or delete a file, access a device, or have read or write permission to a socket for communicating over the Internet.

Privileges can either be automatic, granted, or applied for.

An automatic privilege exists when there is no requirement to have permission to perform an action. For example, on systems where people are required to log into a system to use it, logging out will not require a privilege. Systems that do not implement file protection - such as MSDOS - essentially give unlimited privilege to perform any action on a file.

A granted privilege exists as a result of presenting some credential to the privilege granting authority. This is usually accomplished by logging on to a system with a username and password, and if the username and password supplied are correct, the user is granted additional privileges.

A privilege is applied for by either an executed program issuing a request for advanced privileges, or by running some program to apply for the additional privileges. An example of a user applying for additional privileges is provided by the sudo command to run a command as the root user, or by the Kerberos authentication system.

Modern processor architectures have CPU modes that allows the OS to run at different privilege levels. Some processors have two levels (such as user and supervisor); i386+ processors have four levels (#0 with the most, #3 with the least privileges). Tasks are tagged with a privilege level. Resources (segments, pages, ports, etc.) and the privileged instructions are tagged with a demanded privilege level. When a task tries to use a resource, or execute a privileged instruction, the processor determines whether it has the permission (if not, a "protection fault" interrupt is generated). This prevents user tasks from damaging the OS or each other.

Actuator Definition, What is Actuator

An actuator is the mechanism by which an agent acts upon an environment. The agent can be either an artificial intelligent agent or any other autonomous being (human, other animal, etc).

Examples and Applications of Actuators

• Human - Arms, hands, fingers, legs
• Part picking robot - Grasping mechanism, moving parts. Examples include solenoids and voice coil actuators.
• Mail transfer agent - Update software
• In engineering, actuators are a subdivision of transducers. They are devices which transform an input signal (mainly an electrical signal) into motion. Electrical motors, pneumatic actuators, hydraulic pistons, relays, comb drive, piezoelectric actuators, thermal bimorphs, Digital Micromirror Devices and electroactive polymers are some examples of such actuators.
• Motors are mostly used when circular motions are needed, but can also be used for linear applications by transforming circular to linear motion with a bolt and screw transducer. On the other hand, some actuators are intrinsically linear, such as piezoelectric actuators.
• In virtual instrumentation actuators and sensors are the hardware complements of virtual instruments. Computer programs of virtual instruments use actuators to act upon real world objects.

Action Statement Definition, What is Action Statement

A action statement is a command used in various programming languages that performs an action such as opening a file, saving a file, etc...

A+ Definition, What is A+

The Comptia A+ is a certification and administrated by Drake Parametric covering both hardware and software for the IBM compatible and Macintosh platforms. The Comptia A+ certification is a nice certification for most computer technical jobs.

CompTIA A+ certification validates the latest skills needed by today's computer support professionals. The CompTIA A+ certification is an certification recognized by major hardware and software distributors, vendors, and resellers. CompTIA A+ confirms a technician's ability to perform tasks such as installation, configuration, diagnosing, preventive maintenance and basic networking. The Comptia A+ exams also cover area domains such as safety, security, and environmental issues and communication and professionalism. Some commonly known A+ certifications are Comptia A+ Essentials, Comptia A+ 220-602, Comptia A+ 220-603, and Comptia A+ 220-604.

Adder Definition, What is an Adder

An adder is a component of a computer processor that adds two numbers sent from the processing instructions. It is also a circuit that sums the amplitudes of two input signals. A half adder is a group of logic gates that are connected to create a logic circuit, incapable of handling addition for two numbers.  A full adder is a circuit that adds two binary numbers.

ADC Definition, What is ADC

ADC is short for Analog Digital Converter, Sometimes called a A-D. An ADC is a device that converts a continuous analog signal to a multi-level digital signal without altering its content. The signals that are monitored are sounds, movement, and temperature into binary code for the PC. There are four commonly used ADC used today; the parallel converter, the successive approximation ADC, voltage-to-frequency ADC and the integrating ADC. The ADC converter may be contained on a single chip or can be one circuit within a chip.

Every camcoder, digital camera, or scanner uses A/D converters to transform the variable charges in CCD and CMOS chips into the binary data that represent pixels. Every cellphone and digital desk phone has an ADC converter that converts the pressure of sound waves into PCM code.

AC Definition, What is AC

An alternating current (AC) is an electrical current whose magnitude and direction vary cyclically, as opposed to direct current, whose direction remains constant. The usual waveform of an AC power circuit is a sine wave, as this results in the most efficient transmission of energy. However in certain applications different waveforms are used, such as triangular or square waves.

Used generically, AC refers to the form in which electricity is delivered to businesses and residences. However, audio and radio signals carried on electrical wire are also examples of alternating current. In these applications, an important goal is often the recovery of information encoded (or modulated) onto the AC signal.

History of AC (Alternating Current)

William Stanley designed one of the first practical devices to transfer AC power efficiently between isolated circuits. Using pairs of coils wound on a common iron core, his design, called an induction coil, was an early precursor of the modern transformer. The system used today was devised by many contributors including Nikola Tesla, George Westinghouse, Lucien Gaulard, John Gibbs, and Oliver Shallenger from 1881 to 1889. AC systems overcame the limitations of direct current systems, such as that which Thomas Edison first used to distribute electricity commercially.

The first long-distance transmission of alternating current took place in 1891 near Telluride, Colorado, followed a few months later in Germany. Thomas Edison strongly advocated the use of direct current (DC), having many patents in that technology, but eventually alternating current came into general use (see War of Currents).

The first modern commercial power plant using three-phase alternating current was at the Mill Creek hydroelectric plant near Redlands, California in 1893. Its designer was Almirian Decker, a brilliant young engineer. Decker's innovative design incorporated 10,000 volt three phase transmission and established the standards for the complete system of generation, transmission and motors used today. And through the use of alternating current, Charles Proteus Steinmetz of General Electric was able to solve many of the problems associated with electricity generation and transmission.

Transmission, distribution, and domestic power supply of AC (Alternating Current)

AC voltage can be stepped up or down by a transformer to a different voltage. Modern High-voltage, direct current electric power transmission systems contrast with the more common alternating-current systems as a means for the bulk transmission of electrical power over long distances. However, these tend to be more expensive and less efficient than transformers, and did not exist when Edison, Westinghouse and Tesla were designing their power systems.

Use of a higher voltage leads to more efficient transmission of power. The power losses in a conductor are a product of the square of the current and the resistance of the conductor, described by the formula P = I2R. This means that when transmitting a fixed power on a given wire, if the current is doubled, the power loss will be four times greater. Since the power transmitted is equal to the product of the current, the voltage and the cosine of the phase difference f (P = IVcosf), the same amount of power can be transmitted with a lower current by increasing the voltage. Therefore it is advantageous when transmitting large amounts of power to distribute the power with high voltages (often hundreds of kilovolts). However, high voltages also have disadvantages, the main ones being the increased insulation required, and generally increased difficulty in their safe handling. In a power plant, power is generated at a convenient voltage for the design of a generator, and then stepped up to a high voltage for transmission. Near the loads, the transmission voltage is stepped down to the voltages used by equipment. Consumer voltages vary depending on the country and size of load, but generally motors and lighting are built to use up to a few hundred volts between phases.

Three-phase electrical generation is very common. Three separate coils in the generator stator are physically offset by an angle of 120 degrees to each other. Three current waveforms are produced that are equal in magnitude and 120 degrees out of phase to each other.

If the load on a three-phase system is balanced equally between the phases, no current flows through the neutral point. Even in the worst-case unbalanced (linear) load, the neutral current will not exceed the highest of the phase currents. For three-phase at low (normal mains) voltages a four-wire system is normally used. When stepping down three-phase, a transformer with a Delta primary and a Star secondary is often used so there is no need for a neutral on the supply side.

For smaller customers (just how small varies by country and age of the installation) only a single phase and the neutral or two phases and the neutral are taken to the property. For larger installations all three phases and the neutral are taken to the main distribution panel. From the three-phase main panel, both single and three-phase circuits may lead off.

Three-wire single phase systems, with a single centre-tapped transformer giving two live conductors, is a common distribution scheme for residential and small commercial buildings in North America. A similar method is used for a different reason on construction sites in the UK. Small power tools and lighting are supposed to be supplied by a local center-tapped transformer with a voltage of 55V between each power conductor and the earth. This significantly reduces the risk of electric shock in the event that one of the live conductors becomes exposed through an equipment fault whilst still allowing a reasonable voltage for running the tools.

A third wire is often connected between non-current carrying metal enclosures and earth ground. This conductor provides protection from electrical shock due to accidental contact of circuit conductors with the case of portable appliances and tools.

(Alternating Current) AC Power Supply Frequencies

The frequency of the electrical system varies by country; most electric power is generated at either 50 or 60 Hz. See List of countries with mains power plugs, voltages and frequencies. Some countries have a mixture of 50 Hz and 60 Hz supplies, notably Japan.

A low frequency eases the design of low speed electric motors, particularly for hoisting, crushing and rolling applications, and commutator-type traction motors for applications such as railways, but also causes a noticeable flicker in incandescent lighting and objectionable flicker of fluorescent lamps. 16.7 Hz power (approx. ? of the mains frequency) is still used in some European rail systems, such as in Austria, Germany, Norway, Sweden and Switzerland.

Off-shore, textile industry, marine, computer mainframe, aircraft, and spacecraft applications sometimes use 400 Hz, for benefits of reduced weight of apparatus or higher motor speeds.

No matter if you need to know "what is a Abstract Syntax Notation One", the definition of a "Abstract Syntax Notation One", or the meaning of a "Abstract Syntax Notation One", you can find it here at Network Liquidators. There's quite a bit of information out there to learn, and it all starts by you having the initiative to seek out that information.

Effects at High Frequencies

A direct, constant, current flows uniformly throughout the cross-section of the (uniform) wire that carries it. With alternating current of any frequency, the current is forced towards the outer surface of the wire, and away from the center. This is due to the fact that an electric charge which accelerates (as is the case of an alternating current) radiates electromagnetic waves, and materials of high conductivity (the metal which makes up the wire) do not allow propagation of electromagnetic waves. This phenomenon is called skin effect.

At very high frequencies the current no longer flows in the wire, but effectively flows on the surface of the wire, within a thickness of a few skin depths. The skin depth is the thickness at which the current density is reduced by 63%. Even at relatively low frequencies used for high power transmission (50-60 Hz), non-uniform distribution of current still occurs in sufficiently thick conductors. For example, the skin depth of a copper conductor is approximately 8.57mm at 60 Hz, so high current conductors are usually hollow to reduce their mass and cost.

Since the current tends to flow in the periphery of conductors, the effective cross-section of the conductor is reduced. This increases the effective AC resistance of the conductor, since resistance is inversely proportional to the cross-sectional area in which the current actually flows. The AC resistance often is many times higher than the DC resistance, causing a much higher energy loss due to skin effectohmic heating (also called I2R loss).

Techniques for Reducing AC (Alternating Current) Resistance

For low to medium frequencies, conductors can be divided into stranded wires, each insulated from one other, and the individual strands specially arranged to change their relative position within the conductor bundle. Wire constructed using this technique is called Litz wire. This measure helps to partially mitigate skin effect by forcing more equal current flow throughout the total cross section of the stranded conductors. Litz wire is used for making high Q inductors, reducing losses in flexible conductors carrying very high currents at power frequencies, and in the windings of devices carrying higher radio frequency current (up to hundreds of kilohertz), such as switch-mode power supplies and radio frequency transformers.
Techniques for reducing radiation loss

As written above, an alternating current is made of electric charge under periodic acceleration, which causes radiation of electromagnetic waves. Energy that is radiated represents a loss. Depending on the frequency, different techniques are used to minimize the loss due to radiation

Twisted pairs
At frequencies up to about 1 GHz, wires are paired together in cabling to form a twisted pair in order to reduce losses due to electromagnetic radiation and inductive coupling. A twisted pair must be used with a balanced signalling system, where the two wires carry equal but opposite currents. The result is that each wire in the twisted pair radiates a signal that is effectively cancelled by the other wire, resulting in almost no electromagnetic radiation.

Coax cables
At frequencies above 1 GHz, unshielded wires of practical dimensions lose too much energy to radiation, so coaxial cables are used instead. A coaxial cable has a conductive wire inside a conductive tube. The current flowing on the inner conductor is equal and opposite to the current flowing on the inner surface of the outer tube. This causes the electromagnetic field to be completely contained within the tube, and (ideally) no energy is radiated or coupled outside the tube. Coaxial cables have acceptably small losses for frequencies up to about 20 GHz. For microwave frequencies greater than 20 GHz, the dielectric losses (due mainly to the dissipation factor of the dielectric layer which separates the inner wire from the outer tube) become too large, making waveguides a more efficient medium for transmitting energy.

Waveguides
Waveguides are similar to coax cables, as both consist of tubes, with the biggest difference being that the waveguide has no inner conductor. Waveguides can have any arbitrary cross section, but rectangular cross section are the most common. With waveguides, the energy is no longer carried by an electric current, but by a guided electromagnetic field. Waveguides have dimensions comparable to the wavelength of the alternating current to be transmitted, so are only feasible at microwave frequencies.

Fiber optics
At frequencies greater than 200 GHz, waveguide dimensions become impractically too small, and the ohmic losses in the waveguide walls become large. Instead, fiber optics, which are a form of dielectric waveguides, can be used. For such frequencies, the concepts of voltages and currents are no longer used.


References

• "AC/DC: What's the Difference?". Edison's Miracle of Light, American Experience. (PBS)
• "AC-DC: Inside the AC Generator". Edison's Miracle of Light, American Experience. (PBS)
• Kuphaldt, Tony R., "Lessons In Electric Circuits : Volume II - AC". March 8, 2003. (Design Science License)
• Nave, C. R., "Alternating Current Circuits Concepts". HyperPhysics.
• "Alternating Current (AC)". Magnetic Particle Inspection, Nondestructive Testing Encyclopedia.
• "Alternating current". Analog Process Control Services.
• Hiob, Eric, "An Application of Trigonometry and Vectors to Alternating Current". British Columbia Institute of Technology, 2004.
• "Introduction to alternating current and transformers". Integrated Publishing.
• "Wind Energy Reference Manual Part 4: Electricity". Danish Wind Industry Association, 2003.
• Chan. Keelin, "Alternating current Tools". JC Physics, 2002.
• "Measurement -> ac". Analog Process Control Services.
• Williams, Trip "Kingpin", "Understanding Alternating Current, Some more power concepts".
• "Table of Voltage, Frequency, TV Broadcasting system, Radio Broadcasting, by Country".
• Professor Mark Csele's tour of the 25 Hz Rankine generating station
• 50/60 hertz information
• AC circuits Animations and explanations of vector (phasor) representation of RLC circuits
• Blalock, Thomas J., "The Frequency Changer Era: Interconnecting Systems of Varying Cycles". The history of various frequencies and interconversion schemes in the US at the beginning of the 20th century

Acknowledgement Definition, What is Acknowledgement

In computing, an Acknowledgement is a signal passed between communicating processes or computers to signify acknowledgement, or receipt of response, as part of a communications protocol. For instance, Acknowledgement packets are used in the Transmission Control Protocol during establishment and termination of connections.

Short for acknowledgement, ACK is a response given by another computer or network device indicating to another computer that it acknowledged the SYN/ACK or other request sent to it.

Access Denied Definition, What is Access Denied

Access Denied is a message displayed when unable to obtain access to a location that you have not been granted the proper access rights or do not have permission to access.

If you are attempting to access a network share or resource on a network, Intranet, or the Internet and are receiving this error, you must contact the administrator or individual responsible for that network to obtain rights to that resource.

Although this error is commonly caused by a user accessing something he or she may not have rights to access, this error can also be caused by a hardware error. If you are attempting to access a hardware device on your computer (not a network) and are receiving this error, it is possible you may have a problem with that device. We recommend you review the support page in our hardware database for additional help or information with the hardware device.

Accelerator Definition, What is Accelerator

Accelerator is usually a device or program designed to improve the speed of a hardware peripheral or software program.

A good example of an accelerator would be a graphics or 3D accelerator. A graphics accelerator is a hardware peripheral that contains its own processor and RAM enabling the card to perform at accelerated speeds without decreasing the performance of the computer.

Other examples of accelerators are various utilities used to increase the performance of hardware devices. For example, a download accelerator is used to help increase the speed of download times on computer modems.

Hardware Accelerator

In computing, hardware acceleration is the use of hardware to perform some function faster than is possible in software running on the normal (general purpose) CPU. Examples of hardware acceleration include blitting acceleration functionality in graphics processing units (GPUs) and instructions for complex operations in CPUs.

The hardware that performs the acceleration, when in a separate unit from the CPU, is referred to as a hardware accelerator, or often more specifically as graphics accelerator or floating-point accelerator, etc. Those terms, however, are outdated and have been replaced with more descriptive terms like video card or graphics card.

Web Accelerator

A web accelerator is a proxy server that reduces web site access times. Web accelerators may use several techniques to achieve this reduction:

• They may cache recently or frequently accessed documents so they may be sent to the client with less latency or at a faster transfer rate than the remote server could.
• They may freshen objects in the cache ensuring that frequently accessed content is readily available for display.
• They may prefetch documents that are likely to be accessed in the near future.
• They may compress documents to a smaller size, for example by reducing the quality of images or by sending only what's changed since the document was last requested.
• They may filter out ads and other undesirable objects so they are not sent to the client at all.
• They may maintain persistent TCP connections between the client and the proxy server.

Web accelerators may be installed on the client (browsing) computer / mobile device or on ISP hosted servers or both. Accelerating delivery through compression requires some type of host based server to collect, compress and then deliver content to a client computer.

As of July 2006, these applications generally serve to improve dial-up, broadband and other connections that users may not be getting the best speed from. Many users can achieve a 2 to 10 times speed increase in average browsing experience, while some report a 5 to 20 times speed increases for specific web sites and pages. Many ISPs offer web accelerators as a part of their dial up and broadband services. Web accelerators are typically designed for web browsing and, sometimes, for e-mailing and can not improve speeds of streaming, gaming, P2P downloads or many other Internet applications.

Other web accelerators are targeted at the web site or web application owners. This type of web accelerator is installed in front of web servers and application servers and use a variety of the above techniques to improve performance to all users accessing the accelerated web sites or web applications.

Active Components Definition, What are Active Components

In electronics, active components are components that can be used to provide power gain in an electronic circuit. This means that the power of their output signal may be more than that of their input signal. This added power is provided by another power source. The most common active components are transistors. One of the basic uses of transistors is in making amplifiers. In a simple transistor amplifier, there's an AC input signal (a current, a voltage or both i.e. a power) that needs to be amplified. A DC power supply is used to provide the additional power needed. This DC supply is said to bias the transistor.

Examples of Active Components

• Transistors >> Bipolar Juction Trasistors >> MOSFETS
• Transistors >> Bipolar Juction Trasistors >> JFETS
• Operational Amplifiers
• Vaccuum Tubes >> Triodes
• Vaccuum Tubes >> Tetrodes
• Vaccuum Tubes >> Pentodes
• Vaccuum Tubes >> Heptodes
• Tunnel Diodes (depending on their bias)

Nonlinear Passive Components

The following devices do not fit the definition generally ascribed to active components, but because of their nonlinear responses, designs, histories, and uses in circuits, are sometimes presented alongside active components in textbooks and educational materials.

• Junction Diodes
• Step recovery Diodes
• Thermionic Diodes
• Thyristors
• Varactor Diodes
• Tunnel Diodes

Adobe Illustrator Definition, What is Adobe Illustrator

Adobe Illustrator is a vector-based drawing program developed and marketed by Adobe Systems.

History of Adobe Illustrator

Adobe Illustrator was first developed for the Apple Macintosh in 1986 (shipping in January 1987) as a logical commercialization of Adobe's in-house font development software and PostScript file format.

Initial Release of Adobe Illustrator

In many ways Illustrator's release was a gamble: the Macintosh did not have high market share, the only printer that could output Illustrator documents was Apple's own LaserWriter (also very new and expensive), and the drawing paradigm of Bezier curves was novel to the mainstream user. Not only did the Macintosh show only monochrome graphics, but display options were basically limited to its built-in 9" monitor. Illustrator helped drive the development of larger monitors for the Macintosh.

Illustrator was a reliable, capable product, however, and its relatively shallow learning curve let users quickly appreciate that the new paradigm was not only better, but finally solved the problem of imprecision from existing programs like MacDraw. It also provided a tool for people who could neither afford nor learn high-end (and perhaps overkill) software such as AutoCAD. Illustrator successfully filled a niche between painting and CAD programs.

Illustrator's power and simplicity derive from the choice of Bezier curves as the primary document element. A degenerate curve provides a line, and circles and arcs (trigonometric shapes) can be emulated closely enough. In a novel twist, Adobe also made Illustrator documents true PostScript files -- if one wanted to print them, one could send them directly to a PostScript printer instead of printing them from Illustrator. Since PostScript is a readable text format, third-party developers also found it easy to write programs that generated Illustrator documents.

Adobe was willing to take risks with Illustrator's user interface. Instead of following Apple's UI guidelines to the letter or imitating other popular Macintosh programs, they made it possible to switch between the various navigation tools (i.e, Zoom and Pan) using various keyboard key combinations.

Adobe Illustrator Versions 2 - 5

Although Adobe developed Illustrator primarily for the Macintosh during its first decade, it sporadically supported other platforms. In the early 1990s, Adobe released versions of Illustrator for NeXT, Silicon Graphics IRIX, and Sun Solaris platforms, but they were discontinued due to poor market acceptance. The first version of Illustrator for Microsoft Windows, version 2.0, was released in early 1989, but it was a flop. The next Windows version, version 4.0, was widely criticized as being too similar to Illustrator 1.1 instead of the Macintosh 3.0 version, and certainly not the equal of Windows' most popular illustration package CorelDraw. (Note that there were no versions 2.0 or 4.0 for the Macintosh.) Version 4 was, however the first version of Illustrator to support editing in preview mode, which did not appear in a Macintosh version until 5.0 in 1993.

Adobe Illustrator Versions 6 - 10

With the introduction of Illustrator 6 in 1996, Adobe made critical changes in the user interface with regards to path editing (and also to converge on the same user interface as Adobe Photoshop), and many users opted not to upgrade. To this day, many users find the changes questionable. Illustrator also began to support TrueType, making the "font wars" between PostScript Type 1 and TrueType largely moot. Like Photoshop, Illustrator also began supporting plug-ins, greatly and quickly extending its abilities.

With true ports of the Macintosh versions to Windows starting with version 7 in 1997, designers could finally standardize on Illustrator. Corel did port CorelDRAW 6.0 to the Macintosh in late 1996, but it was received as too little, too late. Aldus ported FreeHand to Windows but it was not the equal of Illustrator. Adobe bought Aldus in 1994 for PageMaker, and as part of the transaction it sold FreeHand to Macromedia.

With the rise of the Internet, Illustrator was enhanced to support Web publishing, rasterization previewing, PDF, and SVG.

Adobe Illustrator Versions CS (11) & CS2 (12)

Adobe Illustrator is currently (as of March 2007) in version 12 (called CS2 to reflect its integration with Adobe's Creative Suite) and is available for both the Mac OS X and Microsoft Windows operating systems. Illustrator CS was the first version to include 3-dimensional capabilities allowing you extrude or revolve shapes to create simple 3-d objects.

Among the new features included in Illustrator CS2 are Live Trace, Live Paint, a control palette and custom workspaces. Live Trace allows for the conversion of bitmap imagery into vector art. Live Paint allows users more flexibility in applying color to objects, specifically those that overlap.

Adobe Illustrator Versions CS (13)

This version of Adobe Illustrator was announced on March 27, 2007, and shipped on April 16. The Mac version is a universal binary. New features include Live Color, which provides tools for creating color harmonies based on color theory, and the ability to dynamically apply colors to selected objects and shift the tone of an entire illustration at one time. Remapping controls are also provided for reducing the numbers of colors in an artwork. Also new are better integration with Flash, with named symbol instances and dynamic/static text; improved drawing tools and controls; faster runtime performance; an Eraser tool that works on vector objects; a Crop Area tool; and an improved Isolation Mode for groups and symbol definitions.

Adobe Illustrator Branding

Starting with version 1.0, Adobe chose to license Sandro Botticelli's "The Birth of Venus" from the Bettmann Archive and use the portion containing Venus' face as Illustrator's branding image. Warnock desired a Renaissance image to evoke his vision of Postscript as a new Renaissance in publishing, and Adobe employee Luanne Seymour Cohen, who was responsible for the early marketing material, found Venus' flowing tresses a perfect vehicle for demonstrating Illustrator's strength in tracing smooth curves over bitmap source images. Over the years the rendition of this image on Illustrator's splash screen and packaging became more stylized to reflect features added in each version.

The image of Venus was replaced in Illustrator CS (11.0) and CS2 (12.0) by a stylized flower to conform to the Creative Suite's nature imagery. In CS3, Adobe changed the suite branding once again, to simple colored blocks with two-letter abbreviations, resembling a periodic table of elements. Illustrator was represented by the letters Ai against an orange background.

Abacus Definition, What is Abacus

An abacus is a mechanical device used to aid an individual in performing mathematical calculations.

The Origin of the Abacus

The origins of the abacus are disputed, as many different cultures have been known to have used similar tools. It is known to have existed in Babylonia and in China, with invention to have taken place between 1000 BCE and 500 BCE. The first abacus was almost certainly based on a flat stone covered with sand or dust. Lines were drawn in the sand and pebbles used to aid calculations. From this, a variety of abaci were developed; the most popular were based on the bi-quinary system, using a combination of two bases (base-2 and base-5) to represent decimal numbers.

The use of the word abacus dates back to before 1387 when a Middle English work borrowed the word from Latin to describe a sandboard abacus. The Latin word came from abakos, the Greek genitive form of abax ("calculating-table"). Because abax also had the sense of "table sprinkled with sand or dust, used for drawing geometric figures," it is speculated by some linguists that the Greek word may be derived from a Semitic root, ābāq, the Hebrew word for "dust." Though details of the transmission are obscure, it may also be derived from the Phoenician word abak, meaning "sand". The plural of abacus is abaci.

Babylonian Abacus

A tablet found on the island of Salamis (near Greece) in 1846 dates back to the Babylonians of 300 BCE making it the oldest counting board discovered so far. It was originally thought to be a gaming board.

Its construction is a slab of white marble measuring 149 cm in length, 75 cm in width and 4.5 cm thick, on which are 5 groups of markings. In the center of the tablet are a set of 5 parallel lines equally divided by a vertical line, capped with a semi-circle at the intersection of the bottom-most horizontal line and the single vertical line. Below these lines is a wide space with a horizontal crack dividing it. Below this crack is another group of eleven parallel lines, again divided into two sections by a line perpendicular to them but with the semi-circle at the top of the intersection; the third, sixth and ninth of these lines are marked with a cross where they intersect with the vertical line.

Roman Abacus

The Late Empire Roman abacus shown here in reconstruction contains eight long grooves containing up to five beads in each and eight shorter grooves having either one or no beads in each.

The groove marked I indicates units, X tens, and so on up to millions. The beads in the shorter grooves denote fives—five units, five tens, etc., essentially in a bi-quinary coded decimal system, obviously related to the Roman numerals. The short grooves on the right may have been used for marking Roman ounces.

Computations are made by means of beads which would probably have been slid up and down the grooves to indicate the value of each column.

Chinese Abacus

The suanpan (Simplified Chinese: 算盘, Traditional Chinese: 算盤; pinyin: suànpán) of the Chinese is similar to the Roman abacus in principle, though has a different construction, and it was designed to do both decimal and hexadecimal arithmetics.

The Chinese abacus is typically around 20 cm (8 inches) tall and it comes in various widths depending on the application. It usually has more than seven rods. There are two beads on each rod in the upper deck and five beads each in the bottom for both decimal and hexadecimal computation. The beads are usually rounded and made of a hard wood. The beads are counted by moving them up or down towards the beam. The abacus can be reset to the starting position instantly by a quick jerk along the horizontal axis to spin all the beads away from the horizontal beam at the center.

Chinese abaci can be used for functions other than counting. Unlike the simple counting board used in elementary schools, very efficient suanpan techniques have been developed to do multiplication, division, addition, subtraction, square root and cube root operations at high speed.

Bead arithmetic is the calculating technique used with various types of abaci, in particular the Chinese abacus. The similarity of the Roman abacus to the Chinese one suggests that one could have inspired the other, as there is some evidence of a trade relationship between the Roman Empire and China. However, no direct connection can be demonstrated, and the similarity of the abaci may be coincidental, both ultimately arising from counting with five fingers per hand. Where the Roman model (like most modern Japanese) has 4 plus 1 bead per decimal place, the standard Chinese abacus has 5 plus 2, allowing less challenging arithmetic algorithms, and also allowing use with a hexadecimal numeral system. Instead of running on wires as in the Chinese and Japanese models, the beads of Roman model runs in groves, presumably making arithmetic calculations much slower. Possibly the Roman abacus was used primarily for simple counting.

Japanese Abacus

Traditional Chinese weighing units used a hexadecimal system which necessitated two beads on the upper deck. The Japanese first eliminated one bead from the upper deck and later another bead from the lower deck in each column of the Chinese abacus, making the Japanese abacus purely for the decimal system. The Japanese also eliminated the use of the Qiuchu (Chinese division table). However, the Chinese division table was still used when there were 5 lower beads. There came the debate of the multiplication table versus the division table, with the school of multiplication table prevailing in the 1920s. The rods (number of digits) usually increase to 21, 23, 27 or even 31, thus allowing calculation for more digits or representations of several different numbers at the same time.

Soroban is taught in primary schools as a part of lessons in mathematics because the decimal numerical system can be demonstrated visually. When teaching the soroban, a song-like instruction is given by the teacher. The soroban is about 8 cm (3 inches) tall. The beads on a soroban are usually shaped as a double cone (bi-cone) to facilitate ease of movement. Often, primary school students may bring along with them two sorobans, one with 1 upper bead and 5 lower beads, the other with 1 upper bead with 4 lower beads. Despite the advent of handheld calculators, some parents send their children to private tutors to learn soroban because proficiency in soroban calculation can be easily converted to mental arithmetic at a highly advanced level.

Russian Abacus

The Russian abacus, the schoty (счёты), usually has a single slanted deck, with ten beads on each wire (except one wire which has four beads, for quarter-ruble fractions). This wire is usually near the user. (Older models have another 4-bead wire for quarter-kopeks, which were minted until 1916.) The Russian abacus is often used vertically, with wires from left to right in the manner of a book. The wires are usually bowed to bulge upward in the center, in order to keep the beads pinned to either of the two sides. It is cleared when all the beads are moved to the right. During manipulation, beads are moved to the left. For easy viewing, the middle 2 beads on each wire (the 5th and 6th bead) usually have a colour different to the other 8 beads. Likewise, the left bead of the thousands wire (and the million wire, if present) may have a different color.

The Russian abacus is still in use today in shops and markets throughout the former Soviet Union, although it is no longer taught in most schools.

School Abacus

Around the world, abaci have been used in pre-schools and elementary schools as an aid in teaching the numeral system and arithmetic. In Western countries, a bead frame similar to the Russian abacus but with straight wires has been common (see image). It is still often seen as a plastic or wooden toy.

The type of abacus shown here is often used to represent numbers without the use of place value. Each bead and each wire has the same value and used in this way it can represent numbers up to 100.

The most significant educational advantage of using an abacus, rather than loose beads or counters, when practicing counting and simple addition is that it gives the student an awareness of the groupings of 10 which are the foundation of our number system. Although adults take this base 10 structure for granted, it is actually difficult to learn. Many 6 year olds can count to 100 by rote with only a slight awareness of the patterns involved.

Native American Abacus

Some sources mention the use of an abacus called a Nepohualtzintzin in ancient Aztec culture. This Mesoamerican abacus uses the 5-digit base-20 system.

The khipu of the Incas was a system of knotted cords used to record numerical data - like advanced tally sticks—but was not used to perform calculations. Calculations were carried out using a yupana (quechua for "counting tool"; see figure) which was still in use after the conquest of Peru. The working principle of a yupana was unknown up to very recent years (2001) when an explanation of the mathematical basis of these instruments has been proposed: comparing the form of several yupanas, it appears that calculations were based using the Fibonacci sequence 1,1,2,3,5 and powers of 10, 20 and 40 as place values for the different fields in the instrument. The Fibonacci sequence is useful to keep the number of grains within any one field at minimum.

Drive Definition, What is a Drive

The A: Drive is a physical drive located on IBM or PC compatible computers. The A: drive is a drive letter that is almost always used for the 3.5-inch floppy disk drive today, but an older computer may be the 5.25-inch drive.

The A: drive is usually the first boot-able drive on IBM compatible computers that helps enable users to use boot-able floppy diskettes to fix and repair their computer.

B: Drive is also another commonly known disk drive just like the A: drive. I know this information is a bit archaic, but never-less, you should at least now about the old school parts of a PC.

System Account Definition, What is a System Account

A system account is a membership with a multi-user network, online service, computer or other device or service that keeps track of various personal information such as rights or privileges, user personal information, access information and various other information about the user or his / her account.

ACPI Definition, What is ACPI

The Advanced Configuration and Power Interface (ACPI) specification is an open industry standard first released in December 1996 developed by HP, Intel, Microsoft, Phoenix and Toshiba that defines common interfaces for hardware recognition, motherboard and device configuration and power management. According to its specification[1], "ACPI is the key element in Operating System-directed configuration and Power Management (OSPM)".

The most widely recognized element of the standard is power management, of which there have been two major improvements. First, it puts the operating system (OS) in control of power management. Conversely, the previously existing APM model assigns power management control to the BIOS, with limited intervention from the OS. In ACPI, the BIOS provides the OS with methods for directly controlling the dirty details of the hardware so it has nearly complete control over the power savings.

The other important feature of ACPI is in bringing power management features previously only available in portable computers to desktop computers and servers. Extremely low consumption states, i.e. in which only memory, or not even memory is powered, but from which ordinary interrupts (real time clock, keyboard, modem, etc.) can quickly wake the system. These modes were previously only available in portable computers.

The standard supports keys on a normal keyboard for suspending or powering off the computer. Some vendors (e.g. ASUS and Compaq) have extended this feature and use it for other keys, especially so-called Power management keys.

ACPI cannot be applied to older hardware; for it to work, the operating system, the motherboard chip-set  and for some functions even the CPU need to be designed for it.

ACPI uses its own ACPI Machine Language (or AML) for implementing power event handlers, rather than the native assembly language of the host system.

The first version of Microsoft Windows to support ACPI was Windows 98. Linux, FreeBSD, NetBSD and OpenBSD all have at least some support for ACPI, though problems tend to arise from buggy implementations, especially those which Microsoft platforms and the Microsoft compiler support (though the implementation is not standards-compliant). Some people misinterpret this as the Microsoft tools being able to work around the bugs, when in fact the Microsoft tools simply allow the bugs to go unchecked and handle them in a non-standards-conforming way.


ACPI Global States

The ACPI specification defines the following seven states (so-called global states) an ACPI-compliant computer system can be in:

G0 Working is the normal working state of the computer, meaning that the operating system and whatever applications run. The CPU(s) execute instructions. Within this state (i.e., without entering G1 Sleeping), it is possible for CPU(s) and devices like hard drives, DVD drives, etc. to be repeatedly put into and come back from low-energy states, called C0–Cn and D0–D3. (Laptops, for example, routinely power down all currently unused devices when running on battery; some computers do this to reduce noise.)

G1 Sleeping subdivides into the four states S1 through S4. The time needed to bring the system from here back into G0 Working (wake-latency time) is shortest for S1, short for S2 and S3, and not so short for S4.

• S1 is the most power-hungry of sleep modes. All processor caches are flushed, and the CPU(s) stop executing instructions. Power to the CPU(s) and RAM is maintained; devices that do not indicate they must remain on may be powered down. Some newer machines do not support S1; older machines are more likely to support S1 than S3.
• S2 is a deeper sleep state than S1, where the CPU is powered off; however, it is not commonly implemented.
• S3 is called Standby in Windows, Sleep in Mac OS X, and sometimes also Suspend to RAM (STR), although the ACPI specification mentions only the term Sleep. In this state, main memory (RAM) is still powered, although it is almost the only component that is. Since the state of the operating system and all applications, open documents, etc. lies all in main memory, the user can resume work exactly where he/she left off—the main memory content when the computer comes back from S3 is the same as when it was put into S3. (The specification mentions that S3 is rather similar to S2, only that some more components are powered down in S3.)
• (Main article: Hibernate (OS feature)). S4 is called Hibernation in Windows, Safe Sleep in Mac OS X, and sometimes also Suspend to disk, although the ACPI specification mentions none of these terms. In this state, all content of main memory is saved to a hard drive, preserving the state of the operating system, all applications, open documents etc. That means that after coming back from S4, the user can resume work where it was left off in much the same way as with S3. The difference between S4 and S3, apart from the added time of moving the main memory content to disk and back, is that a power loss of a computer in S3 makes it lose all data in main memory, including all unsaved documents, while a computer in S4 is unaffected. (S4 is quite different from the other S states and actually resembles G2 Soft Off and G3 Mechanical Off more than it resembles S1–S3.)

G2 Soft Off (also known as S5) is almost the same as G3 Mechanical Off, which means among other things that the boot procedure must be run to bring the system from G2 to G0 Working. A key difference is that G3 Mechanical Off is entered only when a power loss occurs, whereas G2 is initiated by the operating system (typically because the user issued a shutdown command in some way). Additionally, for functionality like starting the system when the space bar on the keyboard is pressed, some components remain powered in G2, which means the computer is not safe for dis-assembly in this state.

G3 Mechanical Off: The computer's power consumption is very close to zero, to the point that the power cord can be removed and the system is safe for dis-assembly (typically, only the real-time clock is running off its own small battery). The computer falls into this state when a power loss occurs, e.g. in case of a power outage. Once power is restored, a full boot procedure is necessary to bring the system from G3 to G0 Working.

Furthermore, a state Legacy is defined as the state when an operating system runs which does not support ACPI. In this state, the hardware and power is not managed via ACPI, effectively disabling ACPI.


ACPI Device States

The device states D0-D3 are device-dependent:

• D0 Fully-On is the operating state.
• D1 and D2 are intermediate power states whose definition varies by device.
• D3 Off has the device powered off and unresponsive to its bus.

ACPI Processor States

The CPU power states C0-C3 are defined as follows:

• C0 is the operating state.
• C1 (often known as Halt) is a state where the processor is not executing instructions, but can return to an executing state essentially instantaneously.
• C2 (often known as Stop-Clock) is a state where the processor maintains all software-visible state, but may take longer to wake up.
• C3 (often known as Sleep) is a state where the processor does not need to keep its cache coherent, but maintains other state. Some processors have variations on the C3 state (Deep Sleep, Deeper Sleep, etc.) that differ in how long it takes to wake the processor.

ACPI Performance States

While a device or processor is operating (D0 and C0, respectively), it can be in one of several power-performance states. These states are implementation-dependent, but P0 is always the highest-performance state, with P1 to Pn being successively lower-performance states, up to an implementation-specific limit of n no greater than 16.

P-states in Intel processors are called SpeedStep, and in AMD processors, Cool'n'Quiet.


ACPI Critique

ACPI is a complex specification (over 500 pages long) that contains multiple components, including declarative tables, an imperative byte-code, and specific hardware components. Concerns have been repeatedly raised that an implementation of ACPI has to run complex, untrusted and potentially buggy bytecode with full privileges, thus potentially making any system that implements ACPI unstable and/or insecure.

Where hardware is non-conforming to ACPI, but claims to be, the software interoperating with that hardware is faced with a dilemma: Either it can be written to be ACPI-compliant, thus risking problems with the not-entirely-compliant hardware, or it can deviate from the ACPI standard to accommodate the hardware quirks. That, however, is generally seen as undesirable from a software-engineering point of view, since the software would potentially have to be adapted for and tested with arbitrarily large numbers of hardware devices, which is precisely what standards such as ACPI are intended to avoid. This is a constant debate between "standards purists" (mainly in the Linux community) and advocates of software that "simply works" with as much hardware as possible.

Access Definition, What is Access

Microsoft Access (current full name Microsoft Office Access) is a relational database management system from Microsoft, packaged with Microsoft Office Professional which combines the relational Microsoft Jet Database Engine with a graphical user interface.

Microsoft Access can use data stored in Access/Jet, Microsoft SQL Server, Oracle, or any ODBC-compliant data container. Skilled software developers and data architects use it to develop powerful, complex application software. Relatively unskilled programmers and non-programmer "power users" can use it to build simple applications without having to deal with features they don't understand. It supports substantial object-oriented (OO) techniques but falls short of being a fully OO development tool.

Microsoft Access was also the name of a communications program from Microsoft, meant to compete with ProComm and other programs. This Microsoft Access proved a failure and was dropped. Years later Microsoft reused the name for its database software.


Microsoft Access History

Microsoft Access version 1.0 was released in November 1992.

Microsoft specified the minimum operating system for Version 1.1 as Microsoft Windows v3.0 with 4 MB of RAM. 6 MB RAM was recommended along with a minimum of 8 MB of available hard disk space (14 MB hard disk space recommended). The product was shipped on seven 1.44 MB diskettes. The manual shows a 1993 copyright date.

The software worked well with very large records sets but testing showed some circumstances caused data corruption. For example, file sizes over 700 MB were problematic. (Note that most hard disks were smaller than 700 MB at the time this was in wide use). The Getting Started manual warns about a number of circumstances where obsolete device drivers or incorrect configurations can cause data loss.

MS-Access's initial codename was Cirrus. This was developed before Visual Basic and the forms engine was called Ruby.

Bill Gates saw the protoypes and decided that the Basic language component should be co-developed as a separate expandable application. This project was called Thunder.

The two projects were developed separately as the underlying forms engines were incompatible with each other; however, these were merged together again after VBA.


Microsoft Access Usage

Access is widely used by small businesses, within departments of large corporations, and hobby programmers to create ad hoc customized systems for handling the creation and manipulation of data. Its ease of use and powerful design tools give the non-professional programmer a lot of power for little effort. However, this ease of use can be misleading. This sort of developer is often an office worker with little or no training in application or data design. Because Access makes it possible even for such developers to create usable systems, many are misled into thinking that the tool itself is limited to such applications.

Some professional application developers use Access for rapid application development, especially for the creation of prototypes and standalone applications that serve as tools for on-the-road salesmen. Access does not scale well if data access is via a network, so applications that are used by more than a handful of people tend to rely on a Client-Server based solution such as Oracle, DB2, Microsoft SQL Server, PostgreSQL, MySQL, MaxDB, or FileMaker. However, an Access "front end" (the forms, reports, queries and VB code) can be used against a host of database backends, including Access itself, Microsoft SQL Server, Oracle, and any other ODBC-compliant product. This approach allows the developer to move a matured application's data to a more powerful server without sacrificing the development already in place.

Many developers who use Microsoft Access use the Leszynski naming convention, though this is not universal; it is a programming convention, not a DBMS-enforced rule.


Microsoft Access Features

One of the benefits of Access from a programmer's perspective is its relative compatibility with SQL – queries may be viewed and edited as SQL statements, and SQL statements can be used directly in Macros and VBA Modules to manipulate Access tables. Users may mix and use both VBA and "Macros" for programming forms and logic and offers object-oriented possibilities.

The report writer in Access is capable and up to the task of sophisticated report creation. MSDE (Microsoft SQL Server Desktop Engine) 2000, a mini-version of MS SQL Server 2000, is included with the developer edition of Office XP and may be used with Access as an alternative to the Jet Database Engine.

The Access cut-and-paste functionality can make it a useful tool for connecting between other databases (for example, Oracle and Microsoft SQL Server during data or database conversions). Access comes with various import and export features that allow integration with Windows and other platform applications, several of which can be executed on demand from within applications or manually by the user. For example the very compact SNP format for sharing perfectly formatted reports with people who don't have the full Access software. It can also easily be upgraded to Microsoft SQL Server.

Unlike a complete RDBMS, the Jet Engine lacks database triggers and stored procedures. Starting in MS Access 2000 (Jet 4.0), there is a syntax that allows creating queries with parameters, in a way that looks like creating stored procedures, but these procedures are limited to one statement per procedure.[1] Microsoft Access does allow forms to contain code that is triggered as changes are made to the underlying table (as long as the modifications are done only with that form), and it is common to use pass-through queries and other techniques in Access to run stored procedures in RDBMSs that support these.

In ADP files (supported in MS Access 2000 and later), the database-related features are entirely different, because this type of file connects to a MSDE or Microsoft SQL Server, instead of using the Jet Engine. Thus, it supports the creation of nearly all objects in the underlying server (tables with constraints and triggers, views, stored procedures and UDF-s). However, only forms, reports, macros and modules are stored in the ADP file (the other objects are stored in the back-end database).


Microsoft Access Development

The programming language available in Access is, as in other products of the Microsoft Office suite, Microsoft Visual Basic for Applications. Two database access libraries of COM components are provided: the legacy Data Access Objects (DAO), only available with Access, and the new ActiveX Data Objects (ADO).

Microsoft Access is easily applied to small projects but scales poorly to large projects owing to weak security and database locking features.

All database queries, forms, and reports are stored in the database, and in keeping with the ideals of the relational model, there is no possibility of making a physically structured hierarchy with them.

One design technique is to divide an Access application between data and programs. One database should contain only tables and relationships, while another would have all programs, forms, reports and queries, and links to the first database tables. Unfortunately, Access allows no relative paths when linking, so the development environment should have the same path as the production environment (Although you can write your own "dynamic-linker" routine in VBA that can search out a certain back-end file by searching through the directory tree, if it can't find it in the current path).

This technique also allows the developer to divide the application among different files, so some structure is possible.

ACCESS Co., Ltd.

ACCESS Co., Ltd. (ACCESS Kabushiki-gaisha Akusesu) (TYO: 4813 ), founded in 1984 in Tokyo, Japan, is a company providing embedded software for connected devices, such as mobile phones, PDAs, video game consoles and set top boxes.

The company gained wide recognition for its NetFront browser product, which has been deployed in over 200 Million devices as of November 2005 (See: http://www.access-us-inc.com/news_releases/20051122a.html), and has been used as a principal element of the widely successful i-mode data service of NTT DoCoMo in Japan. It is also in use by the Sony PSP as the web browser for versions 2.0 and above.

In September 2005, ACCESS has acquired PalmSource, the owners of the Palm OS and BeOS.

ACCESS.bus

ACCESS.bus (or A.b) is a peripheral-interconnect computer bus developed by Philips in the early 1990s. It is similar in purpose to USB, in that it allows low-speed devices to be added or removed from a computer on the fly. While it was in use earlier than USB, it never became popular, largely due to considerably less corporate backing in the industry.

A.b is a physical layer definition that describes the physical cabling and connectors used in the network. The higher layers, namely the signaling and protocol issues, are already defined to be the same as Philips' I²C bus.

Compared to I²C, A.b:

adds two additional pins to provide power to the devices (+5 V and GND)
allows for only 125 devices out of I²C's 1024
supports only the 100 kbit/s "standard mode" and 10 kbit/s "low-speed mode"
The idea was to define a single standard that could be used both inside and outside a computer. A single I²C/A.b controller chip would be used inside the machine, connected on the motherboard to internal devices like the clock and battery power monitor. An A.b connector on the outside would then allow additional devices to be plugged into the bus. This way all of the low- and medium-speed devices on the machine would be driven by a single controller and protocol stack.

A.b also defined a small set of standardized device classes. These included monitors, keyboards, "locators" (pointing devices like mice and joysticks), battery monitors, and "text devices" (modems, etc.). Depending on how much intelligence the device needed, the interface in the device could leave almost all of the work to the driver. This allows A.b to scale down to price points low enough for devices like mice.

Although A.b mice and keyboards have been available (in limited fashion) for some time, the only serious attempt to use the system was by the VESA group. They needed a standardized bus for communicating device abilities between monitors and computers, and selected I²C because it required only two pins. Re-using existing "reserved" pins in the standard VGA connector allows for a complete A.b implementation (including power). A number of monitors with A.b connectors started appearing in the mid-1990s, but this was at about the same time USB was being created. So while many still use the system to communicate to the graphics card, few (if any) include the A.b connector.

Compared to USB, A.b has several advantages. One is that any device on the bus can be a master or a slave, and a protocol is defined for selecting which one a device should use under any particular circumstance. This allows devices to be plugged together with A.b without any computer. For instance, a digital camera could be plugged directly into a printer and become the master. Under USB the computer is always the master and the devices are always slaves. In order to support the same sort of device-to-device connection, USB requires additional support in the dual role OTG devices, to emulate a host and provide similar functionality (although higher data rates). Another advantage of A.b is that devices can be strung together into a single daisy-chain—A.b can support, but does not require, the use of hubs. This can reduce cable-clutter significantly.

On the downside, A.b is much slower than USB. Had IEEE 1394 (also known as FireWire) been widely available at the time, a computer with both A.b and FireWire would have been an attractive solution for all speed ranges. As it was, USB fit neatly into the niche between the two. With USB soon included in the standard motherboard control chips from Intel, A.b was pushed out onto the low-end and quickly disappeared.