Wednesday, 28 September 2011

expension card

The expansion card (also expansion board, adapter card or accessory card) in computing is a printed circuit board that can be inserted into an expansion slot of a computer motherboard or backplane to add functionality to a computer system via the expansion bus.
One edge of the expansion card holds the contacts (the edge connector) that fit exactly into the slot. They establish the electrical contact between the electronics (mostly integrated circuits) on the card and on the motherboard.

Connectors mounted on the bracket allow the connection of external devices to the card. Depending on the form factor of the motherboard and case, around one to seven expansion cards can be added to a computer system. 19 or more expansion cards can be installed in backplane systems. There are also other factors involved in expansion card capacity. For example, most graphics cards on the market as of 2010 are dual slot graphics cards, using the second slot as a place to put an active heat sink with a fan.

Some cards are "low-profile" cards, meaning that they are shorter than standard cards and will fit in a lower height computer chassis. (There is a "low profile PCI card" standard[1] that specifies a much smaller bracket and board area). The group of expansion cards that are used for external connectivity, such as network, SAN or modem cards, are commonly referred to as input/output cards (or I/O cards).

The primary purpose of an expansion card is to provide or expand on features not offered by the motherboard. For example, the original IBM PC did not provide graphics or hard drive capability. In that case, a graphics card and an ST-506 hard disk controller card provided graphics capability and hard drive interface respectively.

In the case of expansion of on-board capability, a motherboard may provide a single serial RS232 port or Ethernet port. An expansion card can be installed to offer multiple RS232 ports or multiple and higher bandwidth Ethernet ports. In this case, the motherboard provides basic functionality but the expansion card offers additional or enhanced ports.

Tuesday, 27 September 2011

my favorite musical instrument

The guitar is a plucked string instrument, usually played with fingers or a pick. The guitar consists of a body with a rigid neck to which the strings, generally six in number, are attached. Guitars are traditionally constructed of various woods and strung with animal gut or, more recently, with either nylon or steel strings. Some modern guitars are made of polycarbonate materials. Guitars are made and repaired by luthiers. There are two primary families of guitars: acoustic and electric.

Acoustic guitars (and similar instruments) with hollow bodies have been in use for over a thousand years. There are three main types of modern acoustic guitar: the classical guitar (nylon-string guitar), the steel-string acoustic guitar, and the archtop guitar. The tone of an acoustic guitar is produced by the vibration of the strings, which is amplified by the body of the guitar, which acts as a resonating chamber. The classical guitar is often played as a solo instrument using a comprehensive fingerpicking technique.

Electric guitars, introduced in the 1930s, rely on an amplifier that can electronically manipulate tone. Early amplified guitars employed a hollow body, but a solid body was found more suitable. Electric guitars have had a continuing profound influence on popular culture. Guitars are recognized as a primary instrument in genres such as blues, bluegrass, country, flamenco, jazz, jota, mariachi, metal, reggae, rock, soul, and many forms of pop.

As you know, I have my own guitar. I really love because somebody give it to me as a my birthday present last year. Until now, I still care the guitar properly. But I'm not too good in playing guitar because it very complicated to learn. It will takes a long time to be expert in playing this kind of musical instrument. The first song that I have learn is Kau Ilhamku from the singer Man Bai. It is a very centimental song for me.

Monday, 26 September 2011

autism

Autism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old.  Autism affects information processing in the brain by altering how nerve cells and their synapses connect and organize; how this occurs is not well understood. It is one of three recognized disorders in the autism spectrum (ASDs), the other two being Asperger syndrome, which lacks delays in cognitive development and language, and Pervasive Developmental Disorder-Not Otherwise Specified (commonly abbreviated as PDD-NOS), which is diagnosed when the full set of criteria for autism or Asperger syndrome are not met.

Autism has a strong genetic basis, although the genetics of autism are complex and it is unclear whether ASD is explained more by rare mutations, or by rare combinations of common genetic variants. In rare cases, autism is strongly associated with agents that cause birth defects. Controversies surround other proposed environmental causes, such as heavy metals, pesticides or childhood vaccines;  the vaccine hypotheses are biologically implausible and lack convincing scientific evidence. The prevalence of autism is about 1–2 per 1,000 people worldwide; however, the Centers for Disease Control and Prevention (CDC) reports approximately 9 per 1,000 children in the United States are diagnosed with ASD. The number of people diagnosed with autism has increased dramatically since the 1980s, partly due to changes in diagnostic practice; the question of whether actual prevalence has increased is unresolved.


Parents usually notice signs in the first two years of their child's life. The signs usually develop gradually, but some autistic children first develop more normally and then regress. Early behavioral or cognitive intervention can help autistic children gain self-care, social, and communication skills. Although there is no known cure, there have been reported cases of children who recovered. Not many children with autism live independently after reaching adulthood, though some become successful. An autistic culture has developed, with some individuals seeking a cure and others believing autism should be accepted as a difference and not treated as a disorder.


Martial art


Martial Arts are extensive systems of codified practices and traditions of combat, practiced for a variety of reasons, including self-defense, competition, physical health and fitness, as well as mental and spiritual development.The term Martial Arts today has become heavily associated with the fighting arts of eastern Asia, but was originally used in regard to the combat systems of Europe as early as the 1550s and an English fencing manual of 1639 used it in reference specifically to the "Science and Art" of swordplay. The term is ultimately derived from Latin, martial arts being the "Arts of Mars," the Roman god of war.
Some Martial Arts are considered "traditional" and tied to an ethnic, cultural or religious background, while others are modern systems developed either by a founder, or by an association.


Taekwondo
Taekwondo (Tae-Kwon-Do, Fist-Foot-Way) is a martial art from Korea (sometimes also spelled Taegwondo). It is a blend of Shotokan Karate with other Chinese and Korean martial arts. Taekwondo places great emphasis on fast, spectacular kicking techniques with very few hand strikes. Competition rules in Taekwondo prohibit the use of throws, holding or grappling. Protective gear is usually worn to allow contact with the body.
Taekwondo tends to place more emphasis on the sport aspect of martial arts. Taekwondo is more of a long range fighting style, due to its use of more kicking than striking. Board breaking is used in belt grading in Taekwondo, to show the power of the techniques being taught (Kyokushin Kai is another martial art that also adheres to this practice).
Taekwondo is popular the world over and is probably the most widely practiced of the martial arts. Taekwondo is now recognised as an Olympic sport, which is sure to popularise it even more.


** Taekwondo is my first martial art that I have learn in secondary school. After enter this college, I choose to learn the other martial art that is Silat Cekak Malaysia. Until now i still learn and just left one stage to finish.  So, I will be graduate later in this kind of martial art! :)