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Архитектура Аудит Военная наука Иностранные языки Медицина Металлургия Метрология Образование Политология Производство Психология Стандартизация Технологии |
Text 8 . The Feedback Loop
The feedback loop is a closed path connecting in sequence a decision that controls action, the level of the system, and information about the level of the system, the latter returning to the decision- making point. The term "level" is used to mean a state or condition of the system. The available information, as it exists at any moment, is the basis for the current decision that controls the action stream. The action alters the level of the system. The level (true level) of the system is the generator of information about the system, but the information itself may be late or erroneous. The information is the apparent level of the system which may differ from the true level. It is the information (apparent level), not the true level, that is the basis for the decision process. The single-loop structure of Figure 1a is the simplest form of feedback system. There may be additional delays and distortions appearing sequentially in the loop. There may be many loops that interconnect.
Figure 1a. The simplest form of feedback system
Ordering replacement goods to maintain an inventory in a warehouse illustrates the circular cause-and-effect structure of the feedback loop as in Figure 1b.
Figure 1b. Cause-and-effect structure of the feedback loop
Here the ordering decision generates a stream of orders to the supplier. The supplier, after a delay to ship or to manufacture, delivers the goods to the inventory. The inventory is the source of information about the inventory, but that information may contain errors and may be delayed so that it does not always reflect the true present level of the inventory. The information about inventory is the input on which the ordering decision is based. (In a more complete system there can, of course, be other inputs to the ordering decision.) The inventory-control loop is in continuous operation. Changes can be occurring at all times at each point around the loop. The present action stream corresponds to the present decision that in turn depends on the present information. However, the present level of the system does not depend on the present action but is instead an accumulation from all past actions. For example, consider a tank that is being filled with water. The height of the water is the system level. The level depends on the accumulation produced by the past flow of water but the level is not determined by how fast water is being added at the present instant. A large stream into an empty tank does not imply a full tank, an already filled tank is not affected if the flow ceases entirely. Information is itself one of the levels of the system (referred to earlier as apparent level). The information changes as it becomes evident that the information differs from the true variable that it is presumed to represent. Information is not determined by the present true condition, which is neither instantaneously nor exactly available, but instead by the past conditions that have been observed, transmitted, analyzed and digested. The discrepancy between a true system level and the information level that governs decisions always exists in principle. As a practical matter, the information is sometimes good enough that no distinction is necessary between true and apparent level.
Exercise 66. Answer the questions on text 8. 1. What is the feedback loop? 2. What does the term “level” mean? 3. What is the basis for current decisions? 4. What can alter the level of the system? 5. What is the difference between the true level and the apparent level of the system? 6. What is the single-loop structure? What may it include? 7. Can you give an example of a circular cause-and-effect structure. 8. What does the present level of the system depend on? 9. When does the information change? 10. What is the information determined by?
Exercise 67. Give Ukrainian equivalents. Available information, current decision, action stream, generator of information, additional delays and distortions, replacement goods, source, to maintain an inventory, warehouse, supplier, complete system, continuous operation, height of the water, empty tank, large stream of orders, true variable, flow.
Exercise 68. Make sure you can translate the noun clusters.
Action stream, feedback system, system level, decision process, true level, customer needs, system performance, lawn-care enterprise, management function, replacement goods.
Exercise 69 . Translate the sentences with Gerund and Participle. Mind the difference in translation. Use the models. Gerund
Participle
1. Ordering the goods in time is essential for any enterprise. 2. I don’t remember having ordered the goods before. 3. When ordering the goods we signed a mutual contract. 4. They insisted on the goods being ordered in time. 5. The goods being ordered by our manager were delivered to the warehouse. 6. The ordered goods were in good condition. 7. The agent informed the seller of the goods having already been ordered. 8. Having ordered the goods, manager was able to write a full report on his work. 9. Having been ordered and delivered the goods were placed in a warehouse. Exercise 7 0 . Compose a dialogue on “Feedback Loop”
Exercise 7 1 . Speak on the topics: 1. The Ubiquity of Systems. 2. Systems – Open and Feedback. 3. The Feedback Loop.
Exercise 72. Learn the following words and word combinations.
Exercise 7 3 . Read, translate and give the gist of text 9. Text 9 . World Dynamics A growing inclination to face the problems of growth has appeared among engineers, businessmen, social scientists, and politicians. Seminars, panel discussions, and debates have proliferated on the future of economic growth. But questioning the present trends of economic growth is much easier than finding answers to the questions of when, how, and for whom economic growth should stop. Before there can be any move away from present policies and practices, alternatives must be identified and explored. The alternatives will involve fundamental changes in laws, values, religious attitudes, and expectations. Years of debate lie ahead in synthesizing a new political rationale that is compatible with a finite world in which human problems can not much longer be solved by expansion. The challenge is to design a path for both industrial and underdeveloped nations through the transition from growth to a viable equilibrium. Only by discovering how the ethical, political, physical, technical, economic and social forces of society interact with one another, can we understand the alternative patterns of future development. As space becomes crowded, the different aspects of society have increasing impact on each other. System dynamics has been instrumental in showing how diverse sectors of society interact to create the problems of growth. What can be expected of system dynamics in finding the alternatives to growth? System dynamics could be the unifying framework and vehicle for interdisciplinary communication. Not only is system dynamics capable of accepting the descriptive knowledge from diverse fields, but it also shows how present policies lead to future consequences. Several years will be required to adequately clarify and argue the nature and merits of future alternatives. Time is short. We must move quickly if we are to keep future options open. Over the last several decades interest in economic development, population growth, and the world environment has expanded rapidly. As world-wide stresses have increased, many individuals and organizations have begun to study and to influence the changing aspects of the world situation. But it seems fair to observe that most of the activity has been addressed to separate facets of the world system. Little has yet been done to show how the many actions and forces are affecting one another to produce the total consequences that we observe. Now however, many persons are coming to believe that the interactions within the whole are more important than the sum of the separate parts. World Dynamics is one step toward showing how the behaviour of the world system results from mutual interplay between its demographic, industrial, and agricultural subsystems. The objective of the project is to understand the options available to mankind as societies enter the transition from growth to equilibrium. Man throughout history has focused on growth – growth in population, standard of living, and geographical boundaries. But in the fixed space of the world, growth must in time give way to equilibrium. Little is known about the social and economic forces that will accompany the entry into world equilibrium.
Exercise 74 . Answer the questions. 1. What inclination has appeared among engineers, businessman and others? 2. What has man focused on throughout history? 3. What must be identified and explored? 4. What will the alternatives to present polices and practices involve? 5. What path is to be designed for both industrial and underdeveloped nations? 6. In what way can we understand the alternative patterns of future development? 7. What are the benefits of system dynamics?
Exercise 75 . Translate the word-combinations from text 9. To lie ahead, a finite world, a political rationale, a challenge, to design a path, underdeveloped nations, the alternative pattern, an increasing impact, system dynamics, diverse sectors, a vehicle for interdisciplinary communication, future consequences, to clarify adequately, mutual interplay, to accompany the entry, to address, to separate facets. Exercise 76 . Complete the sentences according to text 9. 1. Interest in … has expanded rapidly. 2. Many individuals and organizations have begun … 3. It seems fair to observe … 4. Little has been done to show … 5. World Dynamics is one step toward … 6. The objective of World Dynamics is … 7. Man throughout history has focused on … 8. Little is known about …
Exercise 77 . Translate the definitions of the words “history” and “story”: History – all the things that happened in the past, especially the political, social, or economic development of a nation. Story – a description of how something happened, that is intended to entertain people and may be true or imaginary.
Exercise 78 . Insert the correct word: history or story. 1. Full … of what happened has never been reported. 2. “The Observer” ran … about the scandal. 3. Throughout … the achievements of women have been largely ignored. 4. A museum is devoted to Ukrainian … 5. The decision that changed the course of … was reasonable. 6. “Being young in Ukraine” is a cover … in this magazine. Exercise 79 . Translate the sentences taking into account the meaning of the dual conjunction “both… and…– як…, так і… ” . 1. The challenge is to design a path for both industrial and underdeveloped nations. 2. She can both speak and write English. 3. Both engineers and social scientists face the problems of growth. 4. System dynamics could be both the unifying framework and vehicle for interdisciplinary communication. 5. Both panel discussions and debates have proliferated on the future of economic growth.
Exercise 80 . Translate the emphatic sentences paying attention to the word order. Mind the rule.
1. Not only is system dynamics capable of accepting the descriptive knowledge, but it also shows how present policies lead to future consequences. 2. But only recently has mankind become aware of rising forces. 3. From such an examination can come improved understanding. 4. From these interactions appears the dynamics of change. 5. On the right is the Dynamics Scheme.
Exercise 8 1. Learn the following words and word combinations.
Exercise 82 . Read, translate and give the gist of text 10.
Text 10 . World System The world system is encountering new pressures. By "world system" we mean man, his social systems, his technology, and the natural environment. These interact to produce growth, change, and stress. It is not new to have great forces generated from within the socio-technical-natural system. But only recently has mankind become aware of rising forces that cannot be resolved by the historical solutions of migration, expansion, economic growth, and technology. The manifestations of stress in the world system are excessive population, rising pollution, and disparity in standards of living. The world system is becoming tightly interrelated. An action in one sector of the system can produce consequences in another sector. Often the consequences are unintended and undesirable. Our knowledge and assumptions about the components of a system, even systems as complex as our social systems, can now be interrelated and examined through special methods. Such is done by organizing the individual concepts into a "model" that reveals the consequences and internal inconsistencies of our assumptions and fragments of knowledge. From such an examination can come a much improved understanding of the world system within which we are enmeshed. A dynamic model of world scope is a model which interrelates population, capital investment, geographical space, natural resources, pollution, and food production. From these major sectors and their interactions appears the dynamics of change in the world system. Rising population creates pressures to increase industrialization, grow more food, and occupy more land. But more food, material goods, and land tend to encourage and permit larger populations. The growth in population, with its attendant industrialization and pollution, comes from circular processes in which each sector both enhances and feeds on other sectors. But in time, growth encounters limits set by nature. Land and natural resources become exhausted, and the pollution-dissipation capacity of the earth becomes overloaded. The battle between the forces of growth and the restraints of nature may be resolved in a number of ways. Man, if he understands well enough and acts wisely, can choose a path out of the conflict of world pressures that is more favourable than present actions, attitudes, and policies portend. Such a path must be toward a non-growing and balanced condition of the world system. The challenge is to choose the best available transition from the past dynamics of growth to a future condition of world equilibrium.
Exercise 83. Answer the questions on text 10. 1. What is meant by “world system”? 2. What are the manifestations of stress in the world? 3. How can our knowledge and assumptions be examined? 4. What is a dynamic model of world scope? 5. How do major sectors interact in the dynamic model? 6. How can the battle between the forces of growth and the restraints of nature be resolved?
Exercise 84. Find in text 10 twenty words that can function both as a noun and verb.
Exercise 85 . Put 5 types of questions to the sentence. In time, growth encounters limits set by nature.
Exercise 86 . Match the terms and their explanations:
1 Note: Verb – to restrain, to complain Noun – restraint, complaint.
Exercise 87 . Fill in the blanks with proper prepositions. 1. The world system is encountering … pressures. 2. There are forces that cannot be resolved … the historical solutions. 3. The manifestations … stress in the world system are excessive population etc. 4. An action … one sector can produce consequences … another sector. 5. Our assumptions … components can be examined … special methods. 6. In circular processes each sector enhances and feeds … other sectors. 7. Man can choose a path … the conflict … world pressures. 8. Such a path must be … a balanced condition of the world system. Exercise 88 . Fill in the blanks with the proper verb in the correct form. What is common between these verbs? (Encourage, enhance, enmesh, entail, entrust, enrich, enlarge, engrave). 1. We are … within the world system. 2. Their names are … on a stone tablet. 3. A 10 percent rise in cigarette prices is not enough to … smokers to stop. 4. A good way to … your vocabulary is to read a daily newspaper. 5. The publicity has … his reputation. 6. Some foreign travel is … in the job. 7. Education can greatly … your life. 8. She … her son’s education to a private tutor.
Exercise 89. Find English equivalents. Природне середовище; історичне рішення; небажані та непередбачені наслідки; рівень життя; більш глибоке розуміння; здатність розсіювати забруднення; збалансований стан; діяти мудро; найсприятливіші дії; світова рівновага; обмеження, що встановлені природою; найкращий наявний перехід до стану рівноваги.
Exercise 90. Compose a dialogue on “Word System Dynamics”.
Exercise 91 . Learn the following words and word combinations.
Exercise 92 . Read, translate and give the gist of text 11.
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