电子信息工程专业英语教程_第5版 模拟试卷AB卷及答案

Technical English Test for Electronic Information Engineering
Department____________ Class___________ Name____________
SECTION 1
Fill in the blanks with proper terms (30 minutes).
SECTION 2
Translate the following passages into Chinese (40 minutes).
1.Digital signal processing tasks can be performed by all processors. Specialized digital signal
processors (DSPs), however, perform these tasks most efficiently and most quickly. While traditional processors follow the V on Neumann architecture model, which assumes a shared single memory to be used for both program instructions and data, DSPs use the Harvard or modified Harvard architecture, which includes multiple program and data memories, along with multiple buses to access them.
2.The basic services that the IMT-2000 network is supposed to provide to its users are: 1.
High-quality voice transmission. 2. Messaging (replacing e-mail, fax, SMS, chat, etc.). 3.
Multimedia (playing music, viewing videos, films, television, etc.). 4. Internet access (Web surfing, including pages with audio and video).
3.The image sensor employed by most digital cameras is a CCD. Some low-end cameras use
CMOS technology. While CMOS sensors will almost certainly improve and become more popular in the future, they probably won't replace CCD sensors in higher-end digital cameras.
4.Make sure the camera has the right resolution for your needs. If you are going to take snapshots
and e-mail them to friends, then you don't need anything more than 640x480 pixel resolution.
Buying the resolution that you need lets you save money (and hard disk space). On the other hand, if you want to print enlarged versions of your photos, you'll need a 2-megapixel or 3-megapixel camera.
SECTION 3
Read the following passages and answer questions (30 minutes).
Passage one
CD-quality audio requires a transmission bandwidth of 1.411 Mbps. Clearly, substantial compression is needed to make transmission over the Internet practical. For this reason, various audio compression algorithms have been developed. Probably the most popular one is MPEG audio, which has three layers (variants), of which MP3 (MPEG audio layer 3) is the most powerful and best known. Large amounts of music in MP3 format are available on the Internet, not all of it legal, which has resulted in numerous lawsuits from the artists and copyright owners. MP3 belongs to the audio portion of the MPEG video compression standard.
Audio compression can be done in one of two ways. In waveform coding the signal is transformed mathematically by a Fourier transform into its frequency components. The amplitude of each component is then encoded in a minimal way. The goal is to reproduce the waveform accurately at the other end in as few bits as possible.
The other way, perceptual coding, exploits certain flaws in the human auditory system to encode a signal in such a way that it sounds the same to a human listener, even if it looks quite different on an oscilloscope. Perceptual coding is based on the science of psychoacoustics—how people perceive sound. MP3 is based on perceptual coding.
The key property of perceptual coding is that some sounds can mask other sounds. Imagine you are broadcasting a live flute concert on a warm summer day. Then all of a sudden, a crew of workmen nearby turns on their jackhammers and start tearing up the street. No one can hear the flute any more. Its sounds have been masked by the jackhammers. For transmission purposes, it is now sufficient to encode just the frequency band used by the jackhammers because the listeners cannot hear the flute anyway. This is called frequency masking—the ability of a loud sound in one frequency band to hide a softer sound in another frequency band that would have been audible in the absence of the loud sound. In fact, even after the jackhammers stop, the flute will be inaudible for a short period of time because the ear turns down its gain when they start and it takes a finite time to turn it up again. This effect is called temporal masking.
Answer the following questions within 50 words. Q1:Why is audio compression needed?
Q2: What is mp3?
Q3: What does the word psychoacoustics mean?
Q4: What is the aim of waveform coding?
Q5: What is perceptual coding?
Passage Two
Although over 50 years old, the standard television signal is still one of the most common way to transmit an image. Figure 1 shows how the television signal appears on an oscilloscope. This is called composite video, meaning that there are vertical and horizontal synchronization (sync) pulses mixed with the actual picture information. These pulses are used in the television receiver to synchronize the vertical and horizontal deflection circuits to match the video being displayed. Each second of standard video contains 30 complete images, commonly called frames. A video engineer would say that each frame contains 525 lines, the television jargon for what programmers call rows. This number is a little deceptive because only 480 to 486 of these lines contain video information; the remaining 39 to 45 lines are reserved for sync pulses to keep the television's circuits synchronized with the video signal.
Determine the following statement is true (T) or false (F):
No. T/F Statement
Q6: ( )The term composite video is an alias of standard television signal.
Q7:( )There are more than one methods for video transmission mentioned in this passage.
Q8:( )The composite video is a combination of frames, picture information and sync pulses.
Q9:( )The number 30 frames/second is a little deceptive.
Technical English Test for Electronic Information Engineering
Department____________ Class___________ Name____________
SECTION 1
Fill in the blanks with proper terms (30 minutes).
SECTION 2
Translate the following passages into Chinese (40 minutes).
5.While traditional processors follow the V on Neumann architecture model, which assumes a
shared single memory to be used for both program instructions and data, DSPs use the Harvard or modified Harvard architecture, which includes multiple program and data memories, along with multiple buses to access them. This arrangement means that much less waiting is required when instructions or numbers are fetched from memory.
6.ITU recommended that all governments reserve spectrum at 2 GHz so devices could roam
seamlessly from country to country. Later, it was recognized that 2 Mbps is not currently feasible for users who are too mobile (due to the difficulty of performing handoffs quickly enough) .
7.Just like a conventional camera, a digital camera has a series of lenses that focus light to create
an image of a scene. But instead of focusing this light onto a piece of film, it focuses it onto a semiconductor device that records light electronically. A microprocessor then breaks this electronic information down into digital data.
8.Make sure the lens will handle the pictures you plan to take. If you don't have the right lens, it
can be hard to take the best pictures. For example, if very crisp detail is important in your pictures, you'll probably want a high optical zoom number. Be sure to try out the lens system on
a camera before you purchase it. Digital cameras come with a huge variety of lenses, so be sure
to shop around.
SECTION 3
Read the following passages and answer questions (30 minutes).
Passage one
Nature moves in the form of a sine wave, be it an ocean wave, earthquake, sonic boom, explosion, sound through air, or the natural frequency of a body in motion. Energy, vibrating particles and other invisible forces pervade our physical universe. Even light–part particle, part wave–has a fundamental frequency, which can be observed as color. Sensors can convert these forces into electrical signals that you can observe and study with an oscilloscope. Oscilloscopes enable scientists, engineers, technicians, educators and others to “see” ev ents that change over time.
Oscilloscopes are indispensable tools for anyone designing, manufacturing or repairing electronic equipment. In today’s fast-paced world, engineers need the best tools available to solve their measurement challenges quickly and accurately. As the eyes of the engineer, oscilloscopes are the key to meeting today’s demanding measurement challenges.
The usefulness of an oscilloscope is not limited to the world of electronics. With the proper transducer, an oscilloscope can measure all kinds of phenomena. A transducer is a device that creates an electrical signal in response to physical stimuli, such as sound, mechanical stress, pressure, light, or heat. A microphone is a transducer that converts sound into an electrical signal.
Oscilloscopes are used by everyone from physicists to television repair technicians. An automotive engineer uses an oscilloscope to measure engine vibrations. A medical researcher uses an oscilloscope to measure brain waves. The possibilities are endless.
Answer the following questions within 50 words.
Q1: Are oscilloscopes signals sources? Why not?
Q2: Does the word “demanding” mean difficult or easy?
Q3: How can an oscilloscope measure the temperature change over time? Q4: What function does a sensor or a transducer perform?
Q5: Please give the reason why oscilloscopes are regarded as the eyes of engineers?
Passage Two
Although over 50 years old, the standard television signal is still one of the most common way to transmit an image. Figure 1 shows how the television signal appears on an oscilloscope. This is called composite video, meaning that there are vertical and horizontal synchronization (sync) pulses mixed with the actual picture information. These pulses are used in the television receiver to synchronize the vertical and horizontal deflection circuits to match the video being displayed. Each second of standard video contains 30 complete images, commonly called frames. A video engineer would say that each frame contains 525 lines, the television jargon for what programmers call rows. This number is a little deceptive because only 480 to 486 of these lines contain video information; the remaining 39 to 45 lines are reserved for sync pulses to keep the television's circuits synchronized with the video signal.
Determine the following statement is true (T) or false (F):
No. T/F Statement
Q6: ( )The term composite video is an alias of standard television signal.
Q7:( )There are more than one methods for video transmission mentioned in this passage.
Q8:( )The composite video is a combination of frames, picture information and sync pulses.
Q9:( )The number 30 frames/second is a little deceptive.
Q10:( )The sync pulses are used to control the deflection circuits in the TV receivers.
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