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Файл:Materials Processing Technology Part 2. Coursebook
.pdf
The neural network is determined by the architecture of the network, the
magnitude of the weights and the mode of operation of the processing element.
7.2 Modeling of automatic welding of titanium components
in a controlled atmosphere
The process of arc welding of long seams in the products of reactive metals
(titanium, molybdenum, etc.) and sealing are characterized by a large number of
hard-identifiable parameters that affect quality and performance. The design of
fuzzy controllers is one of the largest application areas of fuzzy logic. This is
expressed as a set of linguistic rules. The objective of the controller was to
maintain a speed by controlling the surface quality of arc welding.
For the most effective management of this process, such methods and tools
of artificial intelligence as fuzzy logic and expert systems are used.
Fuzzy logic control replaces the role of the mathematical model with
another model built from a number of smaller rules that in general only describe a
small section of the whole system. The process of inference binds them together
to produce the desired outputs.
The purpose of control is to vary the behavior of a system by changing the
inputs of this system according to a rule, or a set of rules, that model how the
system operates. The controller requires the expert knowledge of the process
operation for the control parameter setting, and the controller can be only as good
as the expertise involved in the design. Controller with a fixed parameter is
inadequate in applications when the operating conditions change in a wide range,
and the available expert knowledge is not reliable.
To develop the fuzzy logic methodology, the diverse steps are crucial:
1) To define the control objectives and criteria (what are we trying to
control, what are we doing to control the system, what kind of response do we
need, what are the possible system failure modes, etc.);
2) To determine the input and output relationships and choose a minimum
number of variables for input into the logic engine;
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3) To use the rule-based structure of controller, break the control problem
down into a series of rules that define the desired system output response for the
given system input conditions. The number and complexity of rules depends on
the number of input parameters that are to be processed and the number of fuzzy
variables associated with each parameter;
4) To create Fuzzy Logic membership functions that define the meaning
(values) of Input/Output terms used in the rules;
5) To test the system, evaluate the results, tune the rules and membership
functions, and retest until satisfactory results are obtained.
7.3 Automation in manufacturing of the gas-dynamic bearings
Gas-dynamic bearings are applied in gyroscopic instruments for control,
orientation and stabilization of moving objects. Bearing consists of one radial and
two identical axial bearings. Gas-dynamic spiral groove with depth of 2-3
microns in both working faces of each bearing is formed to create the desired
axial load capacity. Radial bearing has spiral groove with depth of 20 microns.
Work axial clearance in the bearing is 1-2 microns.
The surface of the bearing is formed by plasma spraying of ceramics. Both
its accuracy and quality depend on the operational properties of the gas-dynamic
bearings. The plasma coating consists mainly of spherical structures.
Improvements of coatings are achieved by optimizing the technological
modes of materials spraying. The main source of information was represented by
the data collected in the study on the morphology of the surface with different
modes of plasma spraying. The microstructure analysis of the data showed that
coatings have structure consisting of particles with spherical shapes.
Developing the algorithms and software for automatic detection of
microparticles in digital images is of practical importance. With these tools
available, we are able to create the automatic evaluation system for specific
parameters of sprayed-on materials seen at the digital photos. We will be able to
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know the relative number of spheroidal particles and thereby forecast
technological and operational properties of a coating.
The spherical micro-particle detection task for the image of some surface
can be formulated as a classifying task for each of snapshot sections containing or
lacking microparticles. Besides, both halftone images and their gradient versions
generated by the Sobel operators were used to identify transitions between the
halftones. When the microparticle contours are similar, the gradient images supply
additional information that provides more reliable detection.
Three hundred negative and positive snapshots were used to train the
detector. This automated analysis of the surface was based on the Principal
Component Analysis method. This method was applied with the help of the
MATLAB software.
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Answer key
Unit 1
Task 1. STUDY SKILL: Noun Compounds
1. a
2. a
3. b
4. b
5. b
6. a
7. b
8. a
9. a
10. b
Task 3. STUDY SKILL: Noun Compounds
1. citrus (peel) oil
2. a human nerve-system map
3. an ethylene dibromide soil fumigant
4. the RNA binding site
5. formaldehyde insulation material
6. the concrete electric-power facility
7. its superconducting-computer research program
8. the background microwave radiation
9. a carbon-nitrogen-oxygen thermonuclear burning cycle
Task 4. STUDY SKILL: Noun Compounds
a noise reduction
blower fan assembly
a Model TL-1 blower
sound-proofing product
the automobile industry
the vinyl floor tiles
air-traffic control centers
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Unit 2
Task 1. DEVELOPING GRAMMAR AND WRITING SKILLS
1. is placed
2. is applied
3. is squeezed
4. melts; falls
5. is started; progresses
6. is shaped
7. leads
8. is stretched
9. is gripped
10. uses
11. has been developed; prevents
12. will be pressed
13. stretches
14. have been produced
Task 3. DEVELOPING GRAMMAR AND WRITING SKILLS
1. The El Niño current killed many fish.
2. Chlorophyll contains magnesium.
3. The “big bang” theory describes the origin of the universe.
4. The machine monitored the patient’s heart beat.
5. A gas pipeline connects the oil fields and the seaport.
6. A volt meter measures the voltage in a system.
7. The I-beam resists compression and tension.
8. The heat of the sun evaporates ocean water, forming clouds.
9. Figure 1 shows the chain reaction in a nuclear power plant.
Task 4. DEVELOPING GRAMMAR AND WRITING SKILLS
1. Glaciers changed many valleys from a V-shape to a U-shape.
2. Penicillin destroys dangerous bacteria.
3. A seismometer measures earthquakes.
4. Welding sometimes produces metallurgical changes in materials.
5. Nitrogen deficiency yellows leaves and stuns plant growth.
6. Fire polishing softens the sharp edges of a new glass tube.
7. A hypertonic solution shrinks blood cells.
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8. Force acting on a rigid body generates a reaction force in the opposite
direction.
Task 5. DEVELOPING GRAMMAR AND WRITING SKILLS
1. Silk is produced by silk worms.
2. {Not necessary.}
3. {Not necessary.}
4. Impossible (sentence is not passive)
5. Honey is made by bees to feed their young.
6. In plants water is absorbed by the roots.
7. {Not really necessary}.
8. {Not necessary}.
Unit 3
Task 1. VOCABULARY DEVELOPMENT
1) a continuous arc 7) molten
2) the nozzle 8) the plasma jet
3) ionized gas 9) ultra-violet light
4) the plasma torch 10) consumable metal wires
5) copper
6) argon
Task 3. VOCABULARY DEVELOPMENT
1) effective 6) efficient 11) effective
2) effective 7) effective 12) efficient
3) effective 8) effective
4) effective 9) effective
5) efficient 10) efficient
Task 4. VOCABULARY DEVELOPMENT
1) impact 6) impact 11) impact
2) influence 7) impact
3) influence 8) impact
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4) impact 9) impact
1) can, can
6) must
11) may
2) can
7) should contain, must
brush, must be, may be
12) must
3) may
8) should, must
13) may
4) can
9) should
14) can
5) may, may
10) may
15) can
5) impact 10) influence
Task 5. VOCABULARY DEVELOPMENT
1) should not 5) may
2) shall 6) may
3) must not 7) shall
4) shall
Task 6. VOCABULARY DEVELOPMENT
1) could/might 5) should
2) might have been 6) may not/might not
3) could/might
4) must
Task 7. VOCABULARY DEVELOPMENT
1) can 5) could
2) could 6) can
3) cannot 7) may not be able to
4) might be able to
Task 8. VOCABULARY DEVELOPMENT
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Unit 4
Task 1. VOCABULARY DEVELOPMENT
1. removes 7. vibrating mill 13. piezoelectric 19. magnetostrictive
2. vibrations 8. transducer 14. voltage cylinder
3. abrasive 9. Oscillator 15. electrodes 20. oscillation
4. slurry 10. Frequency 16. ferromagnetic
5. grain 11. Mechanical 17. magnetic field
6. brittle 12. Machining 18. current
Task 2. VOCABULARY DEVELOPMENT
1. I 7. h
2. c 8. l
3. j 9. b
4. e 10. f
5. a 11. g
6. k 12. d
Task 1. PREPOSITIONS
1. at 5. at 9. at
2. in 6. at 10. on
3. on 7. on; in 11. at
4. on 8. on 12. On
Task 2. PREPOSITIONS
1. from…to 6. from/ between … to /and
2. from…through 7. through
3. until 8. between/ from … and /to
4. from … until(to) 9. from/ between … to/and
5. between …and
Task 3. PREPOSITIONS
1. by /in
2. in
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3. by
4. By
5. by
6. by
7. in; in
Task 4. PREPOSITIONS
1. throughout 6. during 11. over
2. during 7. during (throughout) 12. during
3. over 8. over
4. during 9. throughout (during)
5. over 10. throughout
Task 1. STUDY SKILL: Using a dictionary
1. electrical, electric 10. Electric, electric
2. electrical 11. electrical
3. electrical 12. electrical
4. electric 13. electrical
5. electric 14. electrical
6. electrical 15. Electric, electric
7. electrical, electrical, electrical, electrical 16. Electric, electrical
8. electrical
9. electrical, electrical
Unit 5
Task 2. STUDY SKILL: Adjective Compounds
1. the 5,000-kilometer highway
2. a drug-induced reaction
3. the copper-ammonia complex
4. a thick-walled artery
5. this widely-used method
6. a three-sided figure
7. the oil-bearing sandstone
8. the five-ton truck
9. synthetic-chemical construction (synthetically-constructed chemicals)
10. smoke-free, low-particulate city air
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Task 3. STUDY SKILL: Adjective Compounds
1. Einstein described the space-time continuum.
2. Sutter Labs is an industrial chemistry laboratory (or industrial-chemistry
laboratory, i.e. that makes industrial chemicals) .
3. A 1-kilowatt power amplifier has been installed.
4. A trimaran is a three-hulled boat.
5. Chlorofluorocarbons disrupt the ozone-layer chemistry.
6. Only use a glass microscope slide. [no change]
7. The pulley has a V-shaped notch.
8. The device utilizes a constant-level speech processing system.
9. This circuit requires thin-film, metal-base transistors.
Unit 7
Task 5 A. VOCABULARY DEVELOPMENT
1. in 8. On 15. On, in, in
2. in 9. on 16. On, on
3. in 10. On 17. In
4. in 11. On, in
5. on 12. On
6. in 13. On
7. into, on 14. On, on
Task 5 B. VOCABULARY DEVELOPMENT
1. from…to 8. at
2. from…to 9. Between…and
3. between…and 10. At, at
4. between… and 11. At
5. at about
6. at, between…and
7. at
Task 5 C. VOCABULARY DEVELOPMENT
1. during
2. during
3. until 10. for
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