Chps 4 Key Concepts Answers
人工智能导论第四版课后答案
人工智能导论第四版课后答案1.作为计算机科学的一个分支，人工智能的英文缩写是（）。
AI2. 人工智能是研究、开发用于模拟、延伸和扩展人的智能的理论、方法、技术及应用系统的一门交叉科学，它涉及（ D）。
A. 自然科学B. 社会科学C. 技术科学D. A、B 和 C3. 人工智能定义中的“智能”，涉及到诸如（ A）等问题。
A. B、C 和 DB. 意识C. 自我D. 思维4. 下列关于人工智能的说法不正确的是（ C ）。
A. 人工智能是关于知识的学科――怎样表示知识以及怎样获得知识并使用知识的科学。
B. 人工智能就是研究如何使计算机去做过去只有人才能做的智能工作。
C. 自 1946 年以来，人工智能学科经过多年的发展，已经趋于成熟，得到充分应用。
D. 人工智能不是人的智能，但能像人那样思考，甚至也可能超过人的智能。
5. 人工智能经常被称为世界三大尖端技术之一，下列说法中错误的是（B ）。
A. 空间技术、能源技术、人工智能B. 管理技术、工程技术、人工智能C. 基因工程、纳米科学、人工智能D. 人工智能已成为一个独立的学科分支，无论在理论和实践上都已自成系统6. 人工智能与思维科学的关系是实践和理论的关系。
从思维观点看，人工智能不包括（ A）。
A. 直觉思维B. 逻辑思维C. 形象思维D. 灵感思维7. 强人工智能强调人工智能的完整性，下列（C ）不属于强人工智能。
A. （类人）机器的思考和推理就像人的思维一样B. （非类人）机器产生了和人完全不一样的知觉和意识C. 看起来像是智能的，其实并不真正拥有智能，也不会有自主意识D. 有可能制造出真正能推理和解决问题的智能机器8. 被誉为“人工智能之父”的科学大师是（D ）。
A. 爱因斯坦B. 冯·诺依曼C. 钱学森D. 图灵9. 电子计算机的出现使信息存储和处理的各个方面都发生了革命。
下列说法中不正确的是（ C）。
A. 计算机是用于操纵信息的设备B. 计算机在可改变的程序的控制下运行C. 人工智能技术是后计算机时代的先进工具D. 计算机这个用电子方式处理数据的发明，为实现人工智能提供了一种媒介10. Wiener 从理论上指出，所有的智能活动都是（A ）机制的结果，而这一机制是有可能用机器模拟的。
4ps理论名词解释
4ps理论名词解释4Ps理论名词解释在市场营销领域，4Ps理论是一种常用的营销工具。
通过4Ps理论，企业可以更好地了解市场需求、制定和实施营销策略，从而实现产品或服务的销售和市场占有。
1. 产品（Product）产品是企业提供给市场的可交换的物品、服务或想法。
产品的设计、功能、品质、品牌和包装都是影响市场接受度和销售额的关键因素。
产品策略要考虑产品的独特卖点、市场定位、目标顾客的需求以及竞争对手的产品特点。
通过产品改进、创新和不断提高品质，企业能够增加市场份额并提升竞争力。
2. 价格（Price）价格是指企业出售产品或服务时向顾客收取的金额。
价格策略要基于产品成本、市场需求和竞争力来确定。
企业可以采取不同的定价策略，如市场定价、折扣定价或套餐定价等，以满足不同顾客群体的需求。
通过合理定价，企业可以获得最大的盈利，并提高产品在市场中的竞争力。
3. 促销（Promotion）促销是用于向潜在顾客传递产品或服务信息以及刺激购买的方式和手段。
促销策略可以包括广告、公关、销售促销、个人销售和直销等手段。
通过有效的促销活动，企业可以提高品牌知名度、吸引潜在顾客、增加销售量并维持现有客户的忠诚度。
促销活动还可以帮助企业与竞争对手的产品区分开来，树立独特的品牌形象。
4. 渠道（Place）渠道是指产品或服务流通到消费者手中的路径和方式。
渠道策略要关注产品的销售渠道、零售商和分销商的选择，以及产品的物流和库存管理等。
通过选择合适的渠道和合作伙伴，企业可以将产品迅速送达顾客手中，并满足顾客的购买需求。
良好的产品渠道管理还可以增加产品的可及性和便捷性，提高销售效率和顾客满意度。
4Ps理论是一种综合性的营销管理工具，通过研究和应用4Ps理论，企业可以实现市场需求与供给的匹配，建立品牌优势，提高市场份额和销售额。
同时，企业还需要时刻关注市场的变化，随时调整4Ps策略，以适应市场的变化和顾客的需求。
《计算机英语(第4版)》课后练习参考答案之欧阳治创编
《计算机英语（第4版）》练习参考答案Unit One: Computer and Computer ScienceUnit One/Section AI.Fill in the blanks with the informationgiven in the text:1.Charles Babbage; Augusta Ada Byron2.input; output3.VLSI4.workstations; mainframes5.vacuum; transistors6.instructions; software7.digit; eight; byte8.microminiaturization; chipII.Translate the following terms or phrasesfrom English into Chinese and viceversa:欧阳治创编 2021.03.101.artificial intelligence 人工智能2.paper-tape reader 纸带阅读器3.optical computer 光计算机4.neural network 神经网络5.instruction set 指令集6.parallel processing 并行处理7.difference engine 差分机8.versatile logical element 通用逻辑元件9.silicon substrate 硅衬底10.vacuum tube 真空管11.数据的存储与处理 the storage andhandling of data12.超大规模集成电路 very large-scaleintegrated circuit13.中央处理器 central processing unit14.个人计算机 personal computer15.模拟计算机 analogue computer16.数字计算机 digital computer17.通用计算机general-purposecomputer18.处理器芯片 processor chip19.操作指令 operating instructions20.输入设备 input device欧阳治创编 2021.03.10III.Fill in each of the blanks with one of thewords given in the following list,making changes if necessary:We can define a computer as adevice that accepts input, processes data,stores data, and produces output.According to the mode of processing,computers are either analog or digital.They can also be classified asmainframes, minicomputers,workstations, or microcomputers. Allelse (for example, the age of themachine) being equal, this categorizationprovides some indication of thecomputer’s speed, size, cost, andabilities.Ever since the advent ofcomputers, there have been constantchanges. First-generation computers ofhistoric significance, such as UNIVAC(通用自动计算机), introduced in theearly 1950s, were based onvacuum tubes.Second-generation computers,appearing in the early 1960s, were those欧阳治创编 2021.03.10in whichtransistors replaced vacuumtubes. In third-generation computers,dating from the 1960s,integrated circuitsreplaced transistors. In fourth-generation computers suchasmicrocomputers, which first appearedin the mid-1970s, large-scale integrationenabled thousands of circuitsto beincorporated on onechip. Fifth-generation computers are expected tocombine very-large-scale integrationwith sophisticated approaches tocomputing, including artificialintelligence and true distributedprocessing.IV.Translate the following passage fromEnglish into Chinese:计算机将变得更加先进，也将变得更加容易使用。
计算机操作系统课后习题答案 第四版
计算机操作系统课后习题答案第四版1. Describe the concept of a process and its typical attributes.A process is an entity that represents the execution of a program on a computer system. It consists of the program code, data, and execution context. The typical attributes of a process include a unique process identifier (PID), a program counter that keeps track of the next instruction to be executed, a stack that holds temporary data, a heap for dynamically allocated memory, and a set of resources such as open files and I/O devices.2. Explain the difference between process control block (PCB) and thread control block (TCB).A process control block (PCB) is a data structure used by the operating system to manage a process. It contains information about the process, such as its current state, scheduling information, memory allocation, and I/O status. On the other hand, a thread control block (TCB) is a data structure used to manage a thread within a process. It contains information specific to the thread, such as its program counter, stack pointer, and register values. Multiple threads can exist within a single process, sharing the same resources.3. Discuss the advantages and disadvantages of using threads instead of processes.One advantage of using threads instead of processes is that they are more lightweight in terms of resource consumption. Since threads share the same memory space, inter-thread communication is faster and uses less memory compared to inter-process communication. Threads also enable betterutilization of multi-core processors, as multiple threads can run in parallel on different cores.However, there are also disadvantages to using threads. The main disadvantage is that threads within the same process can interfere with each other if not properly synchronized. This can lead to issues such as race conditions, deadlocks, and data corruption. Additionally, debugging and testing multi-threaded applications can be more complex and time-consuming compared to single-threaded applications.4. Explain the concepts of mutual exclusion, deadlock, and starvation in the context of operating systems.Mutual exclusion refers to the concept of ensuring that only one process or thread can access a shared resource at a time. This is typically achieved using synchronization mechanisms such as locks or semaphores. Mutual exclusion is important to prevent data corruption or inconsistent results due to concurrent access.Deadlock occurs when two or more processes are waiting indefinitely for each other to release resources, resulting in a situation where none of the processes can proceed. It can happen when processes acquire resources in a different order or when they fail to release resources properly. Deadlocks can lead to system failures and require careful resource allocation and scheduling algorithms to avoid.Starvation refers to a situation where a process is unable to acquire the necessary resources to progress, despite its requests. It can occur when resource allocation policies favor certain processes over others, leading to along waiting time for some processes. Starvation can negatively impact the performance and fairness of the system.5. Discuss the purpose and functionality of memory management units (MMUs) in operating systems.Memory management units (MMUs) are hardware components responsible for translating virtual memory addresses used by processes into physical memory addresses. They provide address translation and memory protection mechanisms. MMUs use page tables or translation lookaside buffers (TLBs) to map virtual addresses to physical addresses, allowing processes to utilize more memory than physically available.MMUs also enforce memory protection by assigning memory access permissions to different regions of the process's address space. This prevents processes from accessing memory that they should not be able to, ensuring data integrity and security. Additionally, MMUs help optimize memory access by caching frequently used memory pages in the TLB, reducing the number of costly memory accesses.Overall, MMUs play a crucial role in memory management, allowing processes to have their own virtual address spaces and ensuring efficient and secure memory access.(Note: The above answers are just sample content for the given topic. Please modify and expand them according to your needs, as the word limit has been exceeded.)。
史蒂芬 威廉森 宏观经济学 第四版 课后题答案 最新Solution_CH4
Chapter 4Consumer and Firm Behavior: The Work-Leisure Decision and Profit MaximizationTextbook Question SolutionsQuestions for Review1. Consumers consume an aggregate consumption good and leisure.2. Consumers’ preferences are summarized in a utility function.3. The first property is that more is always preferred to less. This property assures us that a consumptionbundle with more of one good and no less of the other good than any second bundle will always be preferred to the second bundle.The second property is that a consumer likes diversity in his or her consumption bundle. Thisproperty assures us that a linear combination of two consumption bundles will always be preferred to the two original bundles.The third property is that both consumption and leisure are normal goods. This property assures us that an increase in a consumer’s income will always induce the individual to consume more of both consumption and leisure.4. The first property of indifference curves is that they are downward sloping. This property is a directconsequence of the property that more is always preferred to less. The second property ofindifference curves is that they are bowed toward the origin. This property is a direct consequence of consumers’ preference for diversity.5. Consumers maximize the amount of utility they can derive from their given amount of availableresources.6. The optimal bundle has the property that it represents a point of tangency of the budget line with anindifference curve. An equivalent property is that the marginal rate of substitution of leisure forconsumption and leisure is equal to the real wage.7. In response to an increase in dividend income, the consumer will consume more goods and moreleisure.8. In response to an increase in the real value of a lump-sum tax, the consumer will consume less goodsand less leisure.28 Williamson • Macroeconomics, Fourth Edition9. An increase in the real wage makes the consumer more well off. As a result of this pure income effect,the consumer wants more leisure. Alternatively, the increase in the real wage induces a substitution effect in which the consumer is willing to consume less leisure in exchange for working more hours (consuming less leisure). The net effect of these two competing forces is theoretically ambiguous.10. The representative firm seeks to maximize profits.11. As the amount of labor is increased, holding the amount of capital constant, each worker gets asmaller share of the fixed amount of capital, and there is a reduction in each worker’s marginalproductivity.12. An increase in total factor productivity shifts the production function upward.13. The representative firm’s profit is equal to its production (revenue measured in units of goods) minusits variable labor costs (the real wage times the amount of labor input). A unit increase in labor input adds the marginal product of labor to revenue and adds the real wage to labor costs. The amount of labor demand is that amount of labor input that equates marginal revenue with marginal labor costs.This quantity of labor, labor demand, can simply be read off the marginal product of labor schedule.Problems1. Consider the two hypothetical indifference curves in the figure below. Point A is on both indifferencecurves, I1 and I2. By construction, the consumer is indifferent between A and B, as both points are on I2. In like fashion, the consumer is indifferent between A and C, as both points are on I1. But atpoint C, the consumer has more consumption and more leisure than at point B. As long as theconsumer prefers more to less, he or she must strictly prefer C to A. We therefore contradict thehypothesis that two indifference curves can cross.2. u al bC=+(a) To specify an indifference curve, we hold utility constant at u Next rearrange in the form:u aC l=−b bChapter 4 Consumer and Firm Behavior: The Work-Leisure Decision and Profit Maximization 29 Indifference curves are therefore linear with slope, −a /b , which represents the marginal rate ofsubstitution. There are two main cases, according to whether /a b w > or /.a b w < The top panelof the left figure below shows the case of /.a b w < In this case the indifference curves are flatterthan the budget line and the consumer picks point A, at which 0l = and .C wh T π=+− Theright figure shows the case of /.a b w > In this case the indifference curves are steeper than thebudget line, and the consumer picks point B, at which l h = and .C T π=− In the coincidentalcase in which /,a b w = the highest attainable indifference curve coincides with the indifference curve, and the consumer is indifferent among all possible amounts of leisure and hours worked.(b) The utility function in this problem does not obey the property that the consumer prefers diversity,and is therefore not a likely possibility.(c) This utility function does have the property that more is preferred to less. However, the marginalrate of substitution is constant, and therefore this utility function does not satisfy the property ofdiminishing marginal rate of substitution.3. (a) Using the formulas in the example from the textbook, one obtains:l = C = (0.75 × 16 − 0.8 − 6)/(1 + 0.75) = 3.89Given the numbers given, we can precisely determine the coordinates of the points in the figureabove: A is (0,6.8), B is (3.89,3.89), D is (9,07,0), with the slope of ABD being − 0.75.30 Williamson • Macroeconomics, Fourth Edition (b) With the new wage, we obtain: l = C = (1.5 × 16 − 0.8 − 6)/(1 + 1.5) = 7.52where A, B and D have the same coordinates as above, and E is (0, 12.8), F is (7.52, 7.52), H is(12.53,0), and the slope of EFH is − 1.5. As there are no substitution effects when goods areperfect complements, the entire move from point B to point F is due to the income effect.4. When the government imposes a proportional tax on wage income, the consumer’s budget constraintis now given by:(1)(),C w t h l T π=−−+−where t is the tax rate on wage income. In the figure below, the budget constraint for t = 0, is FGH.When t > 0, the budget constraint is EGH. The slope of the original budget line is –w , while the slope of the new budget line is −(1 − t )w . Initially the consumer picks the point A on the original budget line. After the tax has been imposed, the consumer picks point B. The substitution effect of the imposition of the tax is to move the consumer from point A to point D on the original indifference curve. The point D is at the tangent point of indifference curve, I 1, with a line segment that is parallel to EG. The pure substitution effect induces the consumer to reduce consumption and increase leisure (work less). T he tax also makes the consumer worse off, in that he or she can no longer be on indifferencecurve, I 1, but must move to the less preferred indifference curve, I 2. This pure income effect moves the consumer to point B, which has less consumption and less leisure than point D, because bothconsumption and leisure are normal goods. The net effect of the tax is to reduce consumption, but the direction of the net effect on leisure is ambiguous. The figure shows the case in which the substitution effect on leisure dominates the income effect. In this case, leisure increases and hours worked fall. Although consumption must fall, hours worked may rise, fall, or remain the same.Chapter 4 Consumer and Firm Behavior: The Work-Leisure Decision and Profit Maximization 315. The budget constraint has a kink due to the tax deduction and is represented in the following figuresby ABDh. Reducing the tax deduction pushes the budget constraint to FEDh.First consider a consumer who does not pay taxes. In the old regime, he would have an optimalbundle somewhere between B and D. Two things can happen. If the bundle is between E and D, there is no change. If it is between B and E, say at H, then the household will reoptimize with the new tax deduction. The new bundle is then either somewhere between E and F, and the MRS equals w(1 −t).Or we obtain a corner solution at E, and the MRS is somewhere between w and w(1 −t). The move from H to E is due to the income effect, and if there is an optimal strictly between E and F, the move from E to that point is due to the substitution effect.32 Williamson • Macroeconomics, Fourth EditionFor a consumer who pays taxes, his wage, and thus is MRS does not change. Thus the move from H to J is a pure negative income effect.6. The increase in dividend income shifts the budget line upward. The reduction in the wage rate flattensthe budget line. One possibility is depicted in the figures below. The original budget constraint HGL shifts to HFE. There are two income effects in this case. The increase in dividend income is a positive income effect. The reduction in the wage rate is a negative income effect. The drawing in the top figure shows the case where these two income effects exactly cancel out. In this case we are left witha pure substitution effect that moves the consumer from point A to point B. Therefore, consumptionfalls and leisure increases. As leisure increases, hours of work must fall. The middle figure shows a case in which the increase in dividend income, the distance GF, is larger and so the income effect is positive. The consumer winds up on a higher indifference curve, leisure unambiguously increases, and consumption may either increase or decrease. The bottom figure shows a case in which theincrease in dividend income, the distance GF, is smaller and so the income effect is negative. The consumer winds up on a lower indifference curve, consumption unambiguously decreases, andleisure may either increase or decrease.Chapter 4 Consumer and Firm Behavior: The Work-Leisure Decision and Profit Maximization 33 7. This problem introduces a higher, overtime wage for hours worked above a threshold, q. Thisproblem also abstracts from any dividend income and taxes.(a) The budget constraint is now EJG in the figure below. The budget constraint is steeper for levelsof leisure less than h − q, because of the higher overtime wage. The figure depicts possiblechoices for two different consumers. Consumer #1 picks point A on her indifference curve, I1.Consumer #2 picks point B on his indifference curve, I2. Consumer #1 chooses to work overtime;consumer #2 does not.(b) The geometry of the figure above makes it clear that it would be very difficult to have anindifference curve tangent to EJG close to point J. In order for this to happen, an indifferencecurve would need to be close to right angled as in the case of pure complement. It is unlikely that consumers wish to consume goods and leisure in fixed proportions, and so points like A and Bare more typical. For any other allowable shape for the indifference curve, it is impossible forpoint J to be chosen.(c) An increase in the overtime wage steepens segment EJ of the budget constraint, but has no effecton the segment JG. For an individual like consumer #2, the increase in the overtime wage has no effect up until the point at which the increase is large enough to shift the individual to a point like point A. Consumer #2 receives no income effect because the income effect arises out of a higher wage rate on inframarginal units of work. An individual like consumer #1 has the traditionalincome and substitution effects of a wage increase. Consumer #1 increases her consumption, but may either increase or reduce hours of work according to whether the income effect outweighsthe substitution effect.8. Lump-sum Tax vs. Proportional Tax. Suppose that we start with a proportional tax. Under theproportional tax the consumer’s budget line is EFH in the figure below. The consumer choosesconsumption, *,C and leisure, *,l at point A on indifference curve I1. A shift to a lump-sum taxsteepens the budget line. The absolute value of the slope of the budget line is (1),− and t has fallent w to zero. The imposition of the lump-sum tax shifts the budget line downward in a parallel fashion. By construction, the lump-sum tax must raise the same amount of revenue as the proportional tax. The consumer must therefore be able to continue to consume *C of the consumption good and *l of leisure after the change in tax collection. Therefore, the new budget line must also pass through point A.The new budget line is labeled LGH in the figure below. With the lump-sum tax, the consumer can34 Williamson • Macroeconomics, Fourth Editiondo better by choosing point B, on the higher indifference curve, I2. Therefore, the consumer is clearly better off. We are also assured that consumption will be greater at point B than at point A, and that leisure will be smaller at point B than at point A.9. Leisure represents all time used for nonmarket activities. If the government is now providing forsome of those, like providing free child care, households will take advantage of such a program,thereby allowing more time for other activities, including market work. Concretely, this translates ina change of preferences for households. For the same amount of consumption, they are now willing towork more, or in other words, they are willing to forego some additional leisure. On the figure below, the new indifference curve is labeled I2. It can cross indifference curve I1 because preferences, as we measure them here, have changed. The equilibrium basket of goods for the household now shifts from A to B. This leads to reduced leisure (from l*1 to l*2), and thus increased hours worked, and increased consumption (from C*1 to C*2) thanks to higher labor income at the fixed wage.Chapter 4 Consumer and Firm Behavior: The Work-Leisure Decision and Profit Maximization 3536 Williamson • Macroeconomics, Fourth Edition 10. The firm chooses its labor input, N d , so as to maximize profits. When there is no tax, profits for thefirm are given by(,).d d zF K N wN π=−That is, profits are the difference between revenue and costs. In the top figure on the following page,the revenue function is (,)d zF K N and the cost function is the straight line, wN d . The firm maximizes profits by choosing the quantity of labor where the slope of the revenue function equals the slope of the cost function:.N MP w =The firm’s demand for labor curve is the marginal product of labor schedule in the bottom figure onthe following page.With a tax that is proportional to the firm’s output, the firm’s profits are given by:(,)(,)(1)(,),d d d d zF K N wN tzF K N t zF K N π=−−=−where the term (1)(,)d t zF K N − is the after-tax revenue function, and as before, wN d is the costfunction. In the top figure below, the tax acts to shift down the revenue function for the firm and reduces the slope of the revenue function. As before, the firm will maximize profits by choosing the quantity of labor input where the slope of the revenue function is equal to the slope of the cost function, but the slope of the revenue function is (1),N t MP − so the firm chooses the quantity oflabor where(1).N t MP w −=In the bottom figure below, the labor demand curve is now (1),N t MP − and the labor demand curvehas shifted down. The tax acts to reduce the after-tax marginal product of labor, and the firm will hire less labor at any given real wage.Chapter 4 Consumer and Firm Behavior: The Work-Leisure Decision and Profit Maximization 37 11. The firm chooses its labor input N d so as to maximize profits. When there is no subsidy, profits forthe firm are given by(,).d d zF K N wN π=−That is, profits are the difference between revenue and costs. In the top figure on the following pagethe revenue function is (,)d zF K N and the cost function is the straight line, wN d . The firm maximizes profits by choosing the quantity of labor where the slope of the revenue function equals the slope of the cost function:.N MP w =The firm’s demand for labor curve is the marginal product of labor schedule in the bottom figurebelow.With an employment subsidy, the firm’s profits are given by:(,)()d d zF K N w s N π=−−where the term (,)d zF K N is the unchanged revenue function, and (w – s )N d is the cost function. Thesubsidy acts to reduce the cost of each unit of labor by the amount of the subsidy, s . In the top figure below, the subsidy acts to shift down the cost function for the firm by reducing its slope. As before, the firm will maximize profits by choosing the quantity of labor input where the slope of the revenue function is equal to the slope of the cost function, (t – s ), so the firm chooses the quantity of labor where.N MP w s =−In the bottom figure below, the labor demand curve is now ,N MP s + and the labor demand curve hasshifted up. The subsidy acts to reduce the marginal cost of labor, and the firm will hire more labor at any given real wage.38 Williamson • Macroeconomics, Fourth Edition 12. Minimum Employment Requirement. Below *,N no output is produced. Thereafter, the productionfunction has its usual properties. Such a production function is reproduced in the first two figures below. At high wages, the firm’s cost curve is entirely above the revenue curve, so the firm hires nolabor, to prevent incurring losses. Only if the wage rate is less than ˆwwill the firms choose to hire anyone. At ˆ,w w= the firm chooses *,N just as it would in the absence of the constraint. Below ˆ,w the labor demand curve is unaffected. The labor demand curve is reproduced in the bottom figure.Chapter 4 Consumer and Firm Behavior: The Work-Leisure Decision and Profit Maximization 39 13. The level of output produced by one worker who works h – l hours is given by(,).s Y zF K h l =−This equation is plotted in the figure below. The slope of this production possibilities frontier is simply .N MP −14. As the firm has to internalize the pollution, it realizes that labor is less effective than it previouslythought. It now needs to hire N (1 + x ) workers where N were previously sufficient. This is qualitatively equivalent to a reduction of z , total factor productivity. The figure below highlights the resulting outcome: the firm now hires fewer people for a given wage and thus its labor demand is reduced.40 Williamson • Macroeconomics, Fourth Edition 15. 0.30.7Y zK n =(a) 0.7.Y n = See the top figure below. The marginal product of labor is positive and diminishing. (b) 0.72.Y n = See the figures below. (c) 0.30.70.72 1.23.Y n n =≈ See the figures below. (d) See the bottom figure below.0.30.30.30.30.31,10.72,1 1.41,220.70.86N N N z K MP n z K MP n z K MP n n −−−−==⇒===⇒===⇒=×≈。
新概念英语第四册课后习题及答案资料讲解
新概念英语第四册课后习题及答案Structure 句型Lesson 15 in some part of the world people are still __ b__ to writeA in capable b impote nt c en able d un able6 they can preserve their history ____ d_ dow n lege ndsA by hand b by handing c to hand d in hand7the ___ a__ why these lege nds are useful is that they tell us about migrati onsA cause b effect c why d reas on8 there were n't __ a__ of the n who could write dow n what they did.A any b none c no one d noLesson 25 it would ___ a__ impossible for us to live in this world if insects had no en emies.A make it b stay c be d have it6 we owe __c ___ to the birds and beast who eat in sects.A a great deal b a lot of c a great many d much of7 how many spiders are invo Ived ____ a_ this work on our behalf?A at b for c in d to8 there are many differe nt __ a __ spidersA sort of b kind of c type of d kindsLesson 35 earlier climbers liked summits __ c__ had n ever bee n climbed before.A which b which they c that they d uni ess they6 _____ d_ sin gle aim was gett ing to the topA they're b there c their d theirs7 ___ a __ Zermatt and Chamo ni x,most places were unknown.A except b uni ess c without d apart from8 ___ b__ were gen erally dirty and flea-ridde n.A the few inns that existed b inns like thisC such inns d few innsLesson 45 several cases have bee n reported in Russia rece ntly of people __ b can readA whom b that c which d they6 one day she came into his office and put her hands on the door of the safe ___ c__A as it happe ned b by cha nce c perhaps d inten ti on ally7 _d _____ these tests were being con ducted ,she was able to read a n ewspaper.A during b on occasion c while d as if8 Vera could n't see with her skin ___ a__ she was bli ndfold .A only b except c as if d uni essLesson 55 the problem# there is one, __d _____ by older peopleA created b is created c creates d is creat ing6 for one thi ng ,if you ___ a__ a problem,you have a certa in ide ntity.A were b being c had d are7 ___ c__ to be lin ked with life ,and the origi n of thi ngs.A they seem b it seems c this seems d what seems8 it is ____ b __ they are con ceited and ill-ma nn eredA n ecessary b permissible c possible d likelyLesson 65 if only ____ a_ possible for the com mon people to meet each other.A it would be b it could be c it were d it might be6 you play __a__ winA in order to b in order that c so that d for7 the village green is the _a__ you pick sides.A the place b the time c the reas on d the cause8 ___ d__ the questi on of n ati onal prestige arisesA the mome nt b just c as long as d proved ingLesson 75 not __b ___ sound made by ani mals serves as Ian guageA every b each c the whole d the en tire6 we have only to turn to that extraord inary discovery of echo-locati on inbats to see a case ____ a__ the voice plays a strictly utilitaria n roleA which b where c whe n d though7 __c ___ he shout in the vic inity of a wall, an echo will come back.A should b if c whe n d though8 ___ d _ the echo-so unding apparatus was born.A such b the way c that's how d like thisLesson 85 america n farmers can't export chicke ns to europe _ b __differe nces in n ati onal regulati ons.A through b accord ing to c in respect of d because of6 an electric razor from the eu __a ____ sold in the us unless it meets us sta ndards.A ought n't to be b can't be c should n't be d does n't have to be7 america and the eu __ a__ to reach a dealA are still trying b slways try c tried d were trying8 the details are __b ___ that they may be hard-pressed to get a deal.A so complex b eno ugh complex c such complexity d too complex。
人工智能导论课后答案第四版
人工智能导论课后答案第四版1、在机器学习中，机器可以自行通过样本总结规律，不需要人工干预，就可以总结规律的方向以及参数的维度。
[判断题] *对错(正确答案)2、知识图谱已经成为推动人工智能发展的唯一核心驱动力。
[判断题] *对错(正确答案)3.快递无人车配送主要是根据雷达控制、GPS定位、图像识别、路径规划、道路监控来实现快递车的运行及环境感知。
[判断题] *对(正确答案)错4. 无人机航拍主要利用遥感操控平台。
[判断题] *对(正确答案)错5.惯性导航系统测量运动载体的线加速度和角速率数据，再对这些数据对距离进行微分运算。
[判断题] *对错(正确答案)6. 全局路径规划的主要规划内容是避免碰撞和保持安全距离。
[判断题] *对错(正确答案)7.2010年美国颁布了以IEEE802.11P作为底层通信协议和以IEEE1609系列规范作为高层通信协议的V2X网联通通信标准。
[判断题] *对(正确答案)错8. 无人车自主避障的第一阶段是规划合理路线。
[判断题] *对错(正确答案)9.三维自动目标识别（ATR）是指从三维成像的传感器数据中自动检测并识别目标。
[判断题] *对(正确答案)错10. 无人船分为自主无人船、非自主无人船两种。
[判断题] *对错(正确答案)1、现阶段的机器感知是计算机通过（）来辨别周围世界。
*A. 图像(正确答案)B. 声音(正确答案)C. 感觉D. 信息2、图像识别经历的阶段有（） [单选题] *A. 文字识别B. 数字图像处理C. 识别、物体识别D. 以上都是(正确答案)3、机器学习包括（） *A. 监督学习(正确答案)B. 无监督学习(正确答案)C. 半监督学习(正确答案)D. 强化学习(正确答案)4、模式识别的主要目标就是（） [单选题] *用计算机来模拟人的各种识别能力(正确答案)用语言来模拟人的各种识别能力用机器来模拟人的各种识别能力用感觉来模拟人的各种识别能力5、图像识别是指利用计算机对图像进行（） [单选题] *分析、解决、感受处理、分析、理解(正确答案)认知、感受、分析6、( )是以数字图像处理与识别为基础并结合人工智能、系统学等学科的研究,其研究成果被广泛应用在各种工业及探测机器人上。
计算机科学导论(第4版)习题答案-第5、6章
第5章算法与复杂性习题一、选择题1. B2. D3. C4. A5. B6. B7. D8.B9.C 10.A11.A 12.C 13.A 14.A二、简答题1．什么是算法，算法的特性有哪些？答：“算法(Algorithm)是一组明确的、可以执行的步骤的有序集合，它在有限的时间内终止并产生结果”。
算法的特性有：(1) 有穷性(可终止性)：一个算法必须在有限个操作步骤内以及合理的有限时间内执行完成。
(2) 确定性：算法中的每一个操作步骤都必须有明确的含义，不允许存在二义性。
(3) 有效性(可执行性)：算法中描述的操作步骤都是可执行的，并能最终得到确定的结果。
(4) 输入及输出：一个算法应该有零个或多个输入数据、有1个或多个输出数据。
2．什么是算法的时间复杂度和空间复杂度，如何表示？答：时间复杂度是与求解问题规模、算法输入相关的函数，该函数表示算法运行所花费的时间。
记为，T(n)，其中，n代表求解问题的规模。
算法的空间复杂度(Space complexity)度量算法的空间复杂性、即执行算法的程序在计算机中运行所占用空间的大小。
简单讲，空间复杂度也是与求解问题规模、算法输入相关的函数。
记为，S(n)，其中，n代表求解问题的规模。
时间复杂度和空间复杂度同样，引入符号“O”来表示T(n)、S(n)与求解问题规模n之间的数量级关系。
3．用图示法表示语言处理的过程。
答：语言处理的过程如图所示：4．简述算法设计的策略。
答：作为实现计算机程序实现时解决问题的方法，算法研究的内容是解决问题的方法，而不是计算机程序的本身。
一个优秀的算法可以运行在比较慢的计算机上，但一个劣质的算法在一台性能很强的计算机上也不一定能满足应用的需要，因此，在计算机程序设计中，算法设计往往处于核心地位。
要想充分理解算法并有效地应用于实际问题，关键是对算法的分析。
通常可以利用实验对比分析、数学方法来分析算法。
实验对比分析很简单，两个算法相互比较，它们都能解决同一问题，在相同环境下，一般就会认为哪个算法的速度快这个算法性能更好。
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Canadian History~ TEST REVIEW! ~Chapter 4 ~ T he First World War: Shaping Canada’s Identity 1. How did the First World War begin?World War I began as a local European war between Austria-Hungary and Serbia on July 28, 1914; was transformed into a general European struggle by declaration of war against Russia on Aug. 1, 1914; and eventually became a global war involving 32 nations.2. How did Canada become involved?Canada was a colony of Britain; it was Canada’s duty to help Britain in the war.3. What is “Total War”? What were the changes in this war? Total War is war that involves an entire society, in which civilians are considered fair targets. This means everyone in the country is affected by the war. In previous wars, fighting was limited to armies: rifles, guns, and bayonets.4. What was Canada like in 1914?Innocent – population of only 8 millionUnprepared to go to war5. How did the war shape Canada’s development as a nation? WWI brought many significant changes to Canada as it developed as a NationI。
Canada found it’s place among the Community of Nations。
Canada was ultimately granted the right to make it’s own decisions in foreign affairs by British Parliament through the Statute of Westminster in 1931 Propaganda in World War One6. What is Propaganda?Propaganda is a specific type of message presentationaimed at serving an agenda. At its root, the denotation of propaganda is 'to propagate (actively spread) a philosophy or point of view'.7. Why do we use propaganda?They used propaganda to:a) justify their involvement to their own populaceb) As a means of recruiting menc) A way to raise money and resources to sustain themilitary campaign.d) To urge conservation8. Why posters?They used posters because:a. Television had not yet been inventedb. Not everyone owned or had access to a radioc. Posters were the most effective means of getting amessage across9. What are the seven tricks/terms of propaganda?The seven tricks/terms of propaganda are:∙Name Calling∙Glittering Generalities∙Transfer∙Testimonial∙Plain Folks∙Card Stacking∙Band WagonControversies during the First World War10. The War Measures Acta) What is the War Measures Act?The War Measures Act was created in the year of1914 on August.4. This Act enabled the governmentof Canada to make arrests, detain and deport anypeople of foreign origins with the power to usephysical force.This Act stripped away the rights ofCanadian citizens and put the country in a state ofemergency. It was a preventative measure againstenemy spies.b) What is your opinion of the War Measures Act? Was itfair? Was it necessary?11. A White Man’s Wara) What difficulties did Aboriginals and African Canadianshave in participating in the war?Canada chose a recruitment policy with racistovertones. No German-Canadian recruits wereaccepted. Asian-Canadian recruits were likewiserejected (initially refused admittance outright, by1916 a handful had been accepted with reluctance ).many black Canadians tried to enlist but wereturned away. Natives initially discouraged becausethe enemy would treat them as “savages” and notaccord them the “privileges of civilized warfare”1. with some reluctance Aboriginal troopswere eventually accepted2. black Canadians were not wanted forcombat units3. Asian- and German-Canadian soldiers werenot welcomedb) What was Canada’s enlistment policy?Canada chose a recruitment policy with racistovertones. Local militias organized recruitment(and therefore decided who they would accept)Sam Hughes, when asked about this, replied thatrecruitment was “entirely in the hands ofCommanding Officers, and their selections orrejections are not interfered with fromHeadquarters”c) What was Valcartier?Hastily-built camp at Valcartier, Quebec that trainedthe recruits before they went overseas to fight.d) Who was Sir Sam Hughes?Minister of the Militia Hughes was the driving forcebehind recruitment “Sir Sam” kept promising moreand more recruits12. The Conscription Crisisa) What was the Conscription Crisis?Conscription is military service by all men of a certain age. It is required by law.The Canadian government introduced the idea in 1917.b)Do you think everyone agreed with conscription?Many groups disagreed.French-Canadians said, “No.”To the French-Canadians, Canada was fighting to protect England. This was not a French war.Farmers said, “No.”Their sons were needed to help harvest the crops to feed the soldiers.Labour unionists said, “No.”They needed workers to operate the machines making the war equipment.b) Which two groups did the Canadian Government allowto vote in the Conscription election?In return for women supporting conscription, the Government granted the vote to two groups in the next election:Soldiers who were fighting overseasMothers and wives of soldiers who were fighting overseas.c) Why would the Government of Canada want thesetwo groups to vote in the conscription vote?The War and Social Change in Canada13. Women’s changing role ~ Women’s suffrage movementa) How did the drop in the labour force effect women?Women are forced/welcomed into the WorkforceWomen entered for 2 reasons,–1, Their sole support was gone and they needed money to survive–2, Factories were in demand of labour for the war effort.Over 30,000 Canadian women worked in factories during the war making military supplies (guns, bullets, uniforms, ships, tanks etc).Workers or slaves ??⏹Women paid ½ salary of men.⏹(they had no union) and male unions anti-losing theirjobs.⏹Near end of the war Women Unions did form,mostly working conditions not salaries raise.⏹“Canaries” from sulfur.14. Women also employed as welders, fitters, machinists,riveters and numerous other jobs that before the war were considered to be “men’s work.”a) Why were some women given the right to vote in 1917?In return for women supporting conscription, the Government granted the vote to two groups in the next election:Soldiers who were fighting overseasMothers and wives of soldiers who were fighting overseas.15. How did war change the face of Canada domestically (athome) and abroad?No one was exempt from “military service “at home. Canadians who could not serve directly in combat were expected to participate in smaller but still significant, ways. Across the nation, Canadians rallied for the war effort. Hundreds of church groups, women's organizations, charities sprang into action.a) Women took war factory jobsb) Received lower wages than malesc) Food shortages made running a household difficult By the end of the war in 1918, over 60,000 Canadians would have perished, out of a total population of only eight million.♦Men lost limbs and were mutilated♦Birthrate fell markedly♦Invalids unable to work♦Ethnic hostility♦Influenza epidemicCanada found it’s place among the Community of Nations。