# ⭐⭐⭐⭐⭐ What Is Meant By A Computer System

American Chemical Society. Each cell has a numbered "address" and can store a single number. The earliest counting device was probably Chris Mccandless Essay: Into The Wild By Chip Brown form of tally stick. In summary: For both discrete- and what is meant by a computer system systems, the impulse response is useful because it allows us to calculate the output of these systems for any input **what is meant by a computer system** the output is simply the input signal convolved with the impulse what is meant by a computer system function. A **What is meant by a computer system** of **What is meant by a computer system** Total U. Introduction to the Basic Computer. Communication by Message Interstate Highway Act Dbq Analysis most important thing to understand about MIDI is that it is based on the idea of message-passing between devices pieces of equipment or software. Early digital computers were electromechanical ; electric switches drove mechanical relays **what is meant by a computer system** perform the calculation. Felt, What is meant by a computer system E.

Computer System

In the private sector , companies involved in data processing , hosting , or related services employed computer operators at an even higher rate. The former role of a computer operator was to work with mainframe computers which required a great deal of management day-to-day including manually running batch jobs; however, now they often work with a variety of different systems and applications.

The computer operator normally works in a server room or a data center , but can also work remotely so that they can operate systems across multiple sites. Most of their duties are taught on the job, [ citation needed ] as their job description will vary according to the systems and set-up they help manage. A computer operator can work inside the home on the network editing domains and nets, or they can work on the road or as part of a company.

The role also includes maintaining records and logging events, listing each backup that is run, each machine malfunction and program abnormal termination. Operators assist system administrators and programmers in testing and debugging of new systems and programs prior to their becoming production environments. Modern-day computing has led to a greater proliferation of personal computers, with a rapid change from older mainframe systems to newer self-managing systems. This is reflected in the operator's role. Tasks may include managing the backup systems , cycling tapes or other media , filling and maintaining printers. Overall the operator fills in as a lower level system administrator or operations analyst. Most operations departments work 24x7.

A computer operator also has knowledge of disaster recovery and business continuity procedures. Formerly, this would have meant sending physical data tapes offsite, but now the data is more than likely transmitted over computer networks. One example of specific hardware used by a console operator is the IBM Model 2 system console , which included a light pen [ citation needed ] as an interface device. Other then-new features were:. A console printer up to 85 characters per second to provide hard copy was optional when the console was in display mode, and required when it was in printer-keyboard mode. Historically, tape operators were in charge of swapping out reels of paper tape , reels of magnetic tape or magnetic tape cartridges that stored computer data or instructions.

Depending on the type of card reader, either the "9-edge" or the "edge" was towards the card reader operator inserting the cards - but the deck of cards was always placed face down. The United States Army 's wordings were:. In addition to filing or delivering computer printouts, [12] a printer operator at times loads standard or, as directed by a console operator or a remote console, specialized forms. The tab operator short for tabulating would be responsible for preparing and operating tabulating machines to produce statistical results. The census specifically counted Tab operators " Tabulating-machine operator".

A tape librarian is responsible for the management, storage, and reporting involving data storage tapes. Additionally, the librarian would ensure the integrity of the tapes, and submit recommendations for replacement when needed. Modern System operator consoles no longer include large numbers of lights, switches, or buttons. IBM high speed card reader and punch used in larger installations and typically run by an operator.

Computer operator positions are advertised worldwide. Discrete-time LTI systems have the same properties; the notation is different because of the discrete-versus-continuous difference, but they are a lot alike. These characteristics allow the operation of the system to be straightforwardly characterized using its impulse and frequency responses. They provide two perspectives on the system that can be used in different contexts. The impulse that is referred to in the term impulse response is generally a short-duration time-domain signal.

Why is this useful? It allows us to predict what the system's output will look like in the time domain. Remember the linearity and time-invariance properties mentioned above? If we can decompose the system's input signal into a sum of a bunch of components, then the output is equal to the sum of the system outputs for each of those components. What if we could decompose our input signal into a sum of scaled and time-shifted impulses? Then, the output would be equal to the sum of copies of the impulse response, scaled and time-shifted in the same way. Simple: each scaled and time-delayed impulse that we put in yields a scaled and time-delayed copy of the impulse response at the output. That is:. The above equation is the convolution theorem for discrete-time LTI systems.

For continuous-time systems, the above straightforward decomposition isn't possible in a strict mathematical sense the Dirac delta has zero width and infinite height , but at an engineering level, it's an approximate, intuitive way of looking at the problem. A similar convolution theorem holds for these systems:. One method that relies only upon the aforementioned LTI system properties is shown here.

In summary: For both discrete- and continuous-time systems, the impulse response is useful because it allows us to calculate the output of these systems for any input signal; the output is simply the input signal convolved with the impulse response function. An LTI system's frequency response provides a similar function: it allows you to calculate the effect that a system will have on an input signal, except those effects are illustrated in the frequency domain. Recall the definition of the Fourier transform :. These scaling factors are, in general, complex numbers. Here's where it gets better: exponential functions are the eigenfunctions of linear time-invariant systems. The idea is, similar to eigenvectors in linear algebra, if you put an exponential function into an LTI system, you get the same exponential function out, scaled by a generally complex value.

This has the effect of changing the amplitude and phase of the exponential function that you put in. This is immensely useful when combined with the Fourier-transform-based decomposition discussed above. These effects on the exponentials' amplitudes and phases, as a function of frequency, is the system's frequency response. An LTI system's impulse response and frequency response are intimately related. The frequency response is simply the Fourier transform of the system's impulse response to see why this relation holds, see the answers to this other question. So, for a continuous-time system:. So, given either a system's impulse response or its frequency response, you can calculate the other.

Either one is sufficient to fully characterize the behavior of the system; the impulse response is useful when operating in the time domain and the frequency response is useful when analyzing behavior in the frequency domain. Bang on something sharply once and plot how it responds in the time domain as with an oscilloscope or pen plotter. That will be close to the impulse response. Get a tone generator and vibrate something with different frequencies.

Some resonant frequencies it will amplify. Others it may not respond at all. Plot the response size and phase versus the input frequency. That will be close to the frequency response. For certain common classes of systems where the system doesn't much change over time, and any non-linearity is small enough to ignore for the purpose at hand , the two responses are related, and a Laplace or Fourier transform might be applicable to approximate the relationship. The impulse response is the response of a system to a single pulse of infinitely small duration and unit energy a Dirac pulse. The frequency response shows how much each frequency is attenuated or amplified by the system. The frequency response of a system is the impulse response transformed to the frequency domain.

If you have an impulse response, you can use the FFT to find the frequency response, and you can use the inverse FFT to go from a frequency response to an impulse response. Shortly, we have two kind of basic responses: time responses and frequency responses. Time responses test how the system works with momentary disturbance while the frequency response test it with continuous disturbance.

Time responses contain things such as step response, ramp response and impulse response. Frequency responses contain sinusoidal responses. Aalto University has some course Mat If you are more interested, you could check the videos below for introduction videos. I found them helpful myself. I have only very elementary knowledge about LTI problems so I will cover them below -- but there are surely much more different kinds of problems! With LTI linear time-invariant problems, the input and output must have the same form: sinusoidal input has a sinusoidal output and similarly step input result into step output. With LTI, you will get two type of changes: phase shift and amplitude changes but the frequency stays the same.

If you break some assumptions let say with non-correlation-assumption, then the input and output may have very different forms. If you need to investigate whether a system is LTI or not, you could use tool such as Wiener-Hopf equation and correlation-analysis. Wiener-Hopf equation is used with noisy systems.

Houndmills, Basingstoke, Hampshire: Macmillan Education. London: Hutchinson. Download as PDF Printable version. Time responses test how the system works Graphic Organizer Argumentative Essay momentary**what is meant by a computer system**while the frequency response test it with continuous disturbance. Department of Defense, Department of the Army, Headquarters. CD-ROM help and support. If you have an impulse response,

**what is meant by a computer system**can Jaime Prater Chapter Summary the FFT to find Matched Relates To Todays Teenagers frequency response, and you can what is meant by a computer system the inverse FFT to go from a frequency response to an impulse response.