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Database CONCEPTS

A database is a structured collection of data. The data are typically organized to model relevant aspects of reality (for example, the availability of rooms in hotels), in a way that supports processes requiring this information (for example, finding a hotel with vacancies).

The term database is correctly applied to the data and their supporting data structures, and not to the database management system (DBMS). The database data collection with DBMS is called a database system.

The term database system implies that the data are managed to some level of quality (measured in terms of accuracy, availability, usability, and resilience) and this in turn often implies the use of a general-purpose database management system (DBMS). A general-purpose DBMS is typically a complex software system that meets many usage requirements to properly maintain its databases which are often large and complex.

Online checking system

1. Today i will show u how to use online checking system and today i will book a chair on the cinema. 

biometrics system

Biometrics (or biometric authentication)refers to the identification of humans by their characteristics or traits. Biometrics is used in computer science as a form of identification and access control. It is also used to identify individuals in groups that are under surveillance.

Biometric identifiers are the distinctive, measurable characteristics used to label and describe individuals.Biometric identifiers are often categorized as physiological versus behavioral characteristics.A physiological biometric would identify by one's voice, DNA, hand print or behavior. Behavioral biometrics are related to the behavior of a person, including but not limited to: typing rhythm, gait, and voice. Some researchers have coined the term behaviometrics to describe the latter class of biometrics.

More traditional means of access control include token-based identification systems, such as a driver's license or passport, and knowledge-based identification systems, such as a password or personal identification number. Since biometric identifiers are unique to individuals, they are more reliable in verifying identity than token and knowledge-based methods; however, the collection of biometric identifiers raises privacy concerns about the ultimate use of this information.

A fingerprint in its narrow sense is an impression left by the friction ridges of a human finger.In a wider use of the term, fingerprints are the traces of an impression from the friction ridges of any part of a human or other primate hand. A print from the foot can also leave an impression of friction ridges. A friction ridge is a raised portion of the epidermis on the digits (fingers and toes), the palm of the hand or the sole of the foot, consisting of one or more connected ridge units of friction ridge skin. These are sometimes known as "epidermal ridges" which are caused by the underlying interface between the dermal papillae of the dermis and the interpapillary (rete) pegs of the epidermis. These epidermal ridges serve to amplify vibrationstriggered, for example, when fingertips brush across an uneven surface, better transmitting the signals to sensory nerves involved in fine texture perception. These ridges also assist in gripping rough surfaces, as well as smooth wet surfaces.

wireless and Bluetooth

Wireless

Wireless telecommunications refers to the transfer of information between two or more points that are not physically connected. Distances can be short, such as a few metres for television remote control, or as far as thousands or even millions of kilometres for deep-space radio communications. It encompasses various types of fixed, mobile, and portable applications, including two-way radios, cellular telephones, personal digital assistants (PDAs), and wireless networking. Other examples of wireless technology include GPS units, garage door openers, wireless computer mice, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones.

Advantages of Wireless 

a. Wireless routers are equipped with modem, network switch (a device that has multiple connection ports for connecting computers and other network devices), wireless access points.

b. Wireless Router can be connected to / from anywhere in your immediate environment or house. That means you can log on and surf the Internet from anywhere around your surrounding.

c.Some of the wireless routers are equipped with a built in firewall to ward of intruders. The configuration options of the firewall are an important consideration when buying a router. Virtually everyone buys and sell online oneway or the other, buying a wireless router with good firewall configuration options can be helpful for security and privacy.

Disadvantages.

a.The wireless connection will be slightly slower than the wired connection. Simply put, wireless or WI-FI transmits through the air and can be blocked interfered with by other waves from the surrounding.

b.Security is one of the main concern when it comes to networking generally, wired network provides for more regid security to wireless. This means that all of your private data stored in your laptop or PDA could be exposed to anyone in the same vicinity. It's possible that an unscrupulous person could obtain passwords and important personal information easily from wireless networks if not properly configured.

c.There is over congestion of WI-FI, especially in the cities where you have a large population of stores and big organisations that transmits over the same channel, causing much interference.

Other devices can be a problem too. Blue tooth devices, cordless telephones and microwaves ovens do cause interference sometimes.

Bluetooth

Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances (using short-wavelength radio transmissions in the Ism band from 2400–2480 MHz) from fixed and mobile devices, creating personal area networks (PANs) with high levels of security. Created by telecoms vendor Ericsson in 1994, it was originally conceived as a wireless alternative to RS-232 data cables. It can connect several devices, overcoming problems of synchronization.

Bluetooth is managed by the Bluetooth Special Interest Group, which has more than 16,000 member companies in the areas of telecommunication, computing, networking, and consumer electronics. The SIG oversees the development of the specification, manages the qualification program, and protects the trademarks. To be marketed as a Bluetooth device, it must be qualified to standards defined by the SIG. A network of patents is required to implement the technology and are licensed only for those qualifying devices; thus the protocol, whilst open, may be regarded as proprietary

Advantages: its wirless theres a whole host of devices that use bluetooth, such as mobile phones, pda's, headsets, also printers, and stereo headphones you plug into your hifi. I use a bluetooth dongle to transfer music from my laptop to my n73. Disadvantages: bluejacking phones with bluetooth can be hacked into this is called bluejacking, its has a limited range usually between 10-100 meters depending on handset, also it can can be a pain to configure and pair up. Bluetooth cant be added on later your phone either has to be built in or you will have to buy a handset with bluetooth on it. Bluetooth is a big drain on batteries.

difference between gps and satellite navigation system

difference between gps and satellite navigation system

he Global Positioning System (GPS) is a space-based satellite navigation system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites. It is maintained by the United States government and is freely accessible to anyone with a GPS receiver.

The GPS program provides critical capabilities to military, civil and commercial users around the world. In addition, GPS is the backbone for modernizing the global air traffic system.

A satellite navigation or SAT NAV system is a system of satellites that provide autonomous geo-spatial positioning with global coverage. It allows small electronic receivers to determine their location (longitude, latitude, and altitude) to within a few metres using time signals transmitted along aline-of-sight by radio from satellites. Receivers calculate the precise time as well as position, which can be used as a reference for scientific experiments. A satellite navigation system with global coverage may be termed a global navigation satellite system or GNSS.

satellite Navigation is just to help you navigate and it probably uses a GPS to help with that 
and GPS is Global Positioning System which tells you where you are not how to get there

and the road map is much cheaper but kind of a hassle when your trying to get somewhere and you don't have a copilot

Write your opinion disadvantage and advantage of portable entertainment devices

Disadvantages 

1-it will effect your eyes because you r concentrated on small area

2-The quality will be poor

3-It is small so its not suitable to watch it as a group

Advantages

1-You can use it in the car while going to long journey

2-It is small so you can use it anywhere and everywhere you go 

3- storage capacity is 1TB (terabyte) so u can insert what you like in the device   

mobile phones

Mobile phone

A mobile phone (also known as a cellular phone, cell phone and a hand phone) is a device that can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile phone operator, allowing access to the public telephone network. By contrast, a cordless telephone is used only within the short range of a single, private base station.

In addition to telephony, modern mobile phones also support a wide variety of other services such as text messaging, MMS, email, Internet access, short-range wireless communications (infrared, Bluetooth), business applications, gaming and photography. Mobile phones that offer these and more general computing capabilities are referred to as smartphones.

Mobile phone features 

 

SIM card

Text messaging

Multi-card hybrid phones

smart phones

SIM card

GSM feature phones require a small microchip called a Subscriber Identity Module or SIM Card, to function. The SIM card is approximately the size of a small postage stamp and is usually placed underneath the battery in the rear of the unit. The SIM securely stores the service-subscriber key (SIM) and the K_i used to identify and authenticate the user of the mobile phone. The SIM card allows users to change phones by simply removing the SIM card from one mobile phone and inserting it into another mobile phone or broadband telephony device.

HI GUYS

 

im mahmood al qubtan high class student im gona post some of my works hope it will be use full for you guys