Cache Memory

A CPU cache is a cache used by the central processing unit of a computer to decrease the average time to access memory. The cache is a smaller, faster memory which stores copies of the data from the most often used main memory locations. As long as most memory accesses are to cached memory locations, the average latency of memory accesses will be closer to the cache latency than to the latency of main memory.

When the processor needs to read or write a location in main memory, it first checks whether that memory location is in the cache. This is accomplished by comparing the address of the memory location to all tags in the cache that may contain that address. If the processor finds that the memory location is in the cache, we say that a cache hit has occurred; otherwise we talk of a cache miss. In the case of a cache hit, the processor immediately reads or writes the information in the cache line. The proportion of accesses that result in a cache hit is known as the hit rate, and is a measure of the effectiveness of the cache.

In the case of a cache miss, most caches assign a new entry, which comprises the tag just missed and a copy of the data from memory. The reference can then be applied to the new entry just as in the case of a hit. Misses are relatively slow because they require the data to be transferred from main memory. This transfer incurs a delay since main memory is much slower than cache memory, and also incurs the overhead for recording the new data in the cache before it is delivered to the processor.

Biotechnology

Biological technology is technology based on biology, particularly when used in agriculture, food science, and medicine. Biotechnology means any technological application that uses biological systems, living organisms, or derivatives thereof, to construct or change products or processes for specific use.

Biotechnology combines disciplines like genetics, molecular biology, biochemistry, embryology and cell biology, which are in turn allied to practical disciplines like chemical engineering, information technology, and robotics.Biotechnology can also be defined as the exploitation of organisms to do practical things and to provide useful products.

One characteristic of biotechnology is the directed use of organisms for the manufacture of organic products (examples include beer and milk products). For another example, naturally present bacteria are utilized by the mining industry in bioleaching. Biotechnology is also used to recycle, treat waste, clean up sites infected by industrial activities (bioremediation), and produce biological weapons.

Uniqueness of Functional illiteracy

When uneducated, one cannot study or engrave at all. In contrast, one who is functionally uneducated has a basic clutch of, but with a variable extent of grammatical precision, and method. In short, when tackled with printed objects, functionally untaught adults cannot function efficiently in current society, and cannot adequately execute fundamental assignments such as filling out an employ application; accepting a legally-binding agreement; following written information; reading a daily article; reading traffic warnings; consulting a glossary; or understanding a bus calendar. Practical illiteracy also strictly limits interaction with information and communication technology.

Aberrations

A lens is a device for either concentrating or diverging light, usually produced from a piece of shaped glass. Lenses do not form perfect images, and there is always some degree of distortion or aberration introduced by the lens which causes the image to be an defective replica of the object. Careful design of the lens system for a exacting application ensures that the aberration is minimized. There are several different types of aberration which can influence image quality.