Cache Memory

CACHE MEMORY

 The Cache Memory is the Memory which is very nearest to the CPU , all the Recent Instructions are Stored into the Cache Memory. The Cache Memory is attached for storing the input which is given by the user and which is necessary for the CPU to Perform a Task. But the Capacity of the Cache Memory is too low in compare to Memory and Hard Disk.

Importance of Cache memory

The cache memory lies in the path between the processor and the memory. The cache memory therefore, has lesser access time than memory and is faster than the main memory. A cache memory have an access time of 100ns, while the main memory may have an access time of 700ns.

The cache memory is very expensive and hence is limited in capacity. Earlier cache memories were available separately but the microprocessors contain the cache memory on the chip itself.
The need for the cache memory is due to the mismatch between the speeds of the main memory and the CPU. The CPU clock as discussed earlier is very fast, whereas the main memory access time is comparatively slower. Hence, no matter how fast the processor is, the processing speed depends more on the speed of the main memory (the strength of a chain is the strength of its weakest link). It is because of this reason that a cache memory having access time closer to the processor speed is introduced.

Level 1 (L1) Cache

It is also called primary or internal cache. It is built directly into the processor chip. It has small capacity from 8 Km to 128 Kb.

Level 2 (L2) Cache

It is slower than L1 cache. Its storage capacity is more, i-e. From 64 Kb to 16 MB. The current processors contain advanced transfer cache on processor chip that is a type of L2 cache. The common size of this cache is from 512 kb to 8 Mb.

Level 3 (L3) Cache

This cache is separate from processor chip on the motherboard. It exists on the computer that uses L2 advanced transfer cache. It is slower than L1 and L2 cache. The personal computer often has up to 8 MB of L3 cache.

Smart Caching

When data is found in the cache, it is called a cache hit, and the effectiveness of a cache is judged by its hit rate. Many cache systems use a technique known as smart caching, in which the system can recognize certain types of frequently used data. The strategies for determining which information should be kept in the cache constitute some of the more interesting problems in computer science.


Source:- https://www.google.co.in/

Virtual Reality- A New World

Virtual Reality

Virtual Reality (VR) is the use of computer technology to create a simulated environment. Unlike traditional user interfaces, VR places the user inside an experience. Instead of viewing a screen in front of them, users are immersed and able to interact with 3D worlds. By simulating as many senses as possible, such as vision, hearing, touch, even smell, the computer is transformed into a gatekeeper to this artificial world. The only limits to near-real VR experiences are the availability of content and cheap computing power.

Virtual Reality technology

Virtual Reality’s most immediately-recognizable component is the head-mounted display (HMD). Human beings are visual creatures, and display technology is often the single biggest difference between immersive Virtual Reality systems and traditional user interfaces. For instance, CAVE automatic virtual environments actively display virtual content onto room-sized screens. While they are fun for people in universities and big labs, consumer and industrial wearables are the wild west.

With a multiplicity of emerging hardware and software options, the future of wearables is unfolding but yet unknown. Concepts such Google Cardboard, Samsung GearVR and Epson Movario are leading the way but there are also players like Meta, Avegant Glyph, Daqri and Magic Leap who may surprise the industry with new levels of immersion and usability. Whomever comes out ahead, the simplicity of buying a helmet-sized device that can work in a living-room, office, or factory floor has made HMDs center stage when it comes to Virtual Reality technologies.

Virtual Reality and the importance of audio-

Hearing is arguably more relevant than vision to a person’s sense of space and human beings react more quickly to audio cues than to visual cues. In order create truly immersive Virtual Reality experiences, accurate environmental sounds and spatial characteristics are a must. These lend a powerful sense of presence to a virtual world. To experience the binaural audio details that go into a Virtual Reality experience, put on some headphones and tinker with this audio infographic published by The Verge.

While audiovisual information is most easily replicated in Virtual Reality, active research and development efforts are still being conducted into the other senses. Tactile inputs such as omni-directional treadmills allow users to feel as though they’re actually walking through a simulation, rather than sitting in a chair or on a couch. Haptics, also known as kinesthetic or touch feedback, has progressed from simple spinning-weight “rumble” motors to futuristic ultrasound technology.

How Virtual Reality is being used today?

Unsurprisingly, the video games industry is one of the largest proponents of Virtual Reality. Support for the Oculus Rift headsets has already been jerry-rigged into games like Skyrim and Grand Theft Auto , but newer games like Elite: Dangerous come with headset support built right in. Many tried-and-true user interface metaphors in gaming have to be adjusted for VR (after all, who wants to have to pick items out of a menu that takes up your entire field of vision?), but the industry has been quick to adapt as the hardware for true Virtual Reality gaming has become more widely available.

Virtual Reality and data visualization

Scientific and engineering data visualization has benefited for years from Virtual Reality, although recent innovation in display technology has generated interest in everything from molecular visualization to architecture to weather models.

VR for aviation, medicine and the military

In aviation, medicine, and the military, Virtual Reality training is an  attractive alternative to live training with expensive equipment, dangerous situations, or sensitive technology. Commercial pilots can use realistic cockpits with VR technology in holistic training programs that incorporate virtual flight and live instruction. Surgeons can train with virtual tools and patients, and transfer their virtual skills into the operating room, and studies have already begun to show that such training leads to faster doctors who make fewer mistakes. Police and soldiers are able to conduct virtual raids that avoid putting lives at risk.

Virtual Reality and the treatment of mental illness

Speaking of medicine, the treatment of mental illness, including post-traumatic stress disorder, stands to benefit from the application of Virtual Reality technology to ongoing therapy programs. Whether it’s allowing veterans to confront challenges in a controlled environment, or overcoming phobias in combination with behavioral therapy, VR has a potential beyond gaming, industrial and marketing applications to help people heal from, reconcile and understand real world experiences.

Source:- https://www.google.co.in/ & http://www.marxentlabs.com/what-is-virtual-reality-definition-and-examples/

Clinomania- Desire to stay in Bed

Clinomania

I am sure, nobody likes waking up early in the morning. Most people try their best to take an extra hour of sleep. But there are some people – we call them clinomaniacs – who find it impossible to get out of the bed. It’s a serious condition where no amount of sleep is good enough.
They think of, is getting another hour of sleep, even though they have slept for 12 or 13 hours already (a healthy adult requires just 7 to 8 hours of sleep). This condition – wherein a person finds it excruciatingly difficult to get out of bed in the morning- is called as clinomania, it is also referred as Dysania at times.

Clinomania is derived from the Greek words “clino”, which means bed and “mania”, which means addiction. Literally speaking, clinomania means “addiction to bed”. Clinomaniacs are people who suffer from this condition and they feel a strong need to be in bed, without any concern whatsoever to their responsibilities in the outside world. This can potentially lead to a host of health issues and personal problems.
Clinomania is a psychological or mental disorder. It is an anxiety disorder and is linked to other anxiety disorders such as depression and chronic fatigue syndrome. Clinomaniacs have an intense desire to escape from their personal and professional responsibilities and simply to sleep as much as they can.

Clinomaniacs can wake up easily enough, but they simply find it impossible to get out of bed.For sure, most of us feel like catching up an extra hour or two of sleep when we feel particularly lazy or tired. But Clinomania is not laziness: Clinomania is often mistaken as laziness, but Laziness and Clinomania are two different things. Clinomania is more of a medical condition where person has no control over his or her desires. where as laziness is nothing but lack of motivation and willingness to take up responsibility.

In clinomania person is willing to refrain himself from sleep but has no control over his or her desires. On the other hand lazy people consciously choose to rest and sleep over any other responsibilities. Clintomania tend to affect all aspects of day to day functioning and causes significant emotional disturbance whereas laziness have a little association with emotions.
It is purely an anxiety disorder. Clinomania is, however closely linked to depression. Not all clinomaniacs are affected by depression, but most people who have depression exhibit clinomania symptoms.

Clinomania Cure

There are a wide variety of treatments recommended for clinomania, which range from natural methods such as exercise and diet, to injection of chemicals such as serotonin. Anyone with clinomania symptoms should get themselves evaluated by an experienced psychologist.

There are many ways how to cure Clinomania or Dysania. Your psychologist can help but all that is too expensive. But don’t give up!1