ch04
市场营销重点课程Ch04 消费者市场和购买行为分析
第四章第一部分消费者市场和购买行为分析（一）单项选择题（在下列每小题中，选择一个最合适的答案。
）1、_________是人类欲望行为最基本的决定因素。
A．文化B．性格C．国家D．社会2、消费者的购买单位是个人或_________。
A．集体B．家庭C．社会D．单位3、大多数消费者只能根据个人好恶和做出购买决策。
A．智慧B．经验C．感觉D．能力4、某种相关群体的有影响力的人物称为。
A．“意见领袖”B．“道德领袖”C．“精神领袖”D．“经济领导者”5、一个人的_________影响着消费需求和对市场营销因素的反应。
A．能力B．个性C．联系D．精神6、不同生活方式_________对产品和品牌有不同的需求。
A．群体B．社会C．模型D．艺术7、马斯洛认为需要按其重要程度分，最低层次需要是指_________。
A．生理需要B．社会需要C．尊敬需要D．安全需要8、_________在人格诸领域中最后形成，反映社会的各项准则，由理想、道德、良心等组成。
A．本我B．超我C．自我D．含我9、_________指存在于人体内驱使人们产生行为的内在刺激力，即内在需要。
A．刺激物B．诱因C．反应D．驱使力10、消费者购买过程是消费者购买动机转化为_________的过程。
A．购买心理B．购买意志C．购买行动D．购买意向11、体育明星和电影明星是其崇拜者的。
A．成员群体B．直接参照群体12、下列哪个因素不是影响消费者购买行为的主要因素_________。
A．文化因素B．社会因素C．自然因素D．个人因素13、对于减少失调感的购买行为，营销者要提供完善的_________，通过各种途径提供有利于本企业和产品的信息，使顾客确信自己购买决定的正确性。
A．售前服务B．售后服务C．售中服务D．无偿服务14、在复杂的购买行为中，消费者购买决策过程的第三个阶段是。
A．确认B．收集信息C．备选产品评估D．决定购买15、消费者对于有些产品品牌差异明显，但消费者不愿花长时间来选择和估价，而是不断变换所购产品的品牌，这种购买行为称为_________。
ch04决策支持系统(新)
Is
中国的陆地面积
960万平方公里
Is型语义网络
3 语义网络
基本的语义关系 (2)属性(类属)关系
Have ：表示一个结点具有另一个结点所描述的属性
Have
鸟
翅膀
Have属性关系语义网络
3 语义网络
基本的语义关系 (2)属性(类属)关系
A-Kind-of ：表示一个事物是另一个事物的一 种类型，表示隶属关系。
❖ 按此规则前提的判断得出结论的判断，由此回溯到上一 个规则的推理，一直回溯到目标的判断。
（2）逆向推理
V V
1、A B->G 2、C D->A 3、E->D
产生式规则库
推理过程：
G
A
B
B、C、E
事实库
D
E
C
3 语义网络
由J.R.Quilian于1968年在研究人类联想记忆时提出 的一种心理学模型。 基本思想： ❖ 用结点表示概念，用弧线表示概念之间的关系，将领
弧是有方向和标注的，方向体现了结点所代表的实体的 主次关系，即结点1为主，结点2为辅；
标注表示所连接的两个实体之间的语义联系。
3 语义网络
试用语义网络表示命题“某学校小学生坐车去春 游”。
某学校
属于 小学生 动作目的 春游
动作方式
坐车
3 语义网络
基本的语义关系
(1)Is-a和Part-of型关系 Is-a：表示一个事物是另一个事物的实例，表示 具体与抽象关系，此关系的一个最主要的特点是 属性的继承关系。
系统工程专业本科学员必修课
决策支持系统
第四章 智能决策支持系 统和智能技术的决策支持
本章内容
➢智能决策支持系统概述 ➢人工智能基本原理 ➢专家系统与智能决策支持系统 ➢神经网络的决策支持 ➢遗传算法的决策支持 ➢机器学习的决策支持
Ch04 一阶过程和二阶过程的动态特性
峰值时间 最大超调nput Signals
Ramp function
xi
a
a=1 称为单位斜坡函数
0
1
t
Sinusoidal function
§4-1 Typical Input Signals
究竟采用哪种典型信号？
取决于系统在正常工况下最常见的输入信号形式 斜坡信号 阶跃信号 脉冲信号 正弦信号 随时间逐渐变化的输入 突然的扰动量、突变的输入 冲击输入 随时间往复变化的输入
1 0
5
wnt
10
15
阻尼系数、特征根与二阶系统单位阶跃响应
阻尼系数 特征根
[s]
二阶系统单位阶跃响应
[s]
[s]
阻尼系数、特征根与二阶系统单位阶跃响应
阻尼系数 特征根
[s]
二阶系统单位阶跃响应
[s]
[s]
§5-4 Time-domain Performance Specifications
时域分析性能指标是以系统对单位阶跃输入的瞬态响应 形式给出的。
§4-3 Transient Response of Second-order Systems
二阶系统：
能够用二阶微分方程描述的系统。 它的典型形式是二阶振荡环节。
形式一：
形式二：
二阶系统的单位阶跃响应
单位阶跃输入
则：
根据二阶系统的 极点分布特点， 分五种情况进行 讨论。
欠阻尼 临界阻尼 过阻尼 零阻尼 负阻尼
t
瞬态响应
稳态响应
——动态性能描述
——稳态性能描述
标准过程输入 一阶系统的瞬态响应 二阶系统的瞬态响应
离散数学CH04_图论_根树
4.6 树
4.6 树
图中的三棵树T1，T2和T3都是带权2，2，3，3，5
的二叉树，它们的权分别是：
W(T1)=2×2＋2×2＋3×3＋5×3＋3×2=38 W(T2)=3×4＋5×4＋3×3＋2×2＋2×1=47 W(T3)=3×3＋3×3＋5×2＋2×2＋2×2=36 以上三棵树都是带权2,2,3,3,5的赋权二叉树，但不 是最优树。
【例】求图所示的二叉树产 生的前缀码。 解：在图(a)中，每一个 分枝点引出的左侧边标记0， 右侧边标记1。由根结点到 树叶的路经上各边的标记组 成的0、1序列作为对应树叶 的标记，如图 (b)所示。产 生的前缀码为： 01,11,000,0010,0011
4.6 树
定理 任意一个前缀码，都对应一个二叉树。 证明：
4.6 树
给定了一个前缀码，设h是其中最长序列的长度。画出一个高为 h的正则二叉树。按定理9.6.7中描述的办法给各边标记0或1。 每一个结点对应一个0、1序列，它是由根结点到该结点的路经 上各边的标记组成的。如果某个0、1序列是前缀码的元素，则 标记该结点。将已标记结点的所有后代和该结点的射出边全部删 除，得到了一个二叉树，再删除未加标记的树叶，就得到要求的 二叉树。
在通信中常用0、1字符串表示英文字母，即用二进制 数表示英文字母。最少用多少位二进制数就能表示26
个英文字母呢？1位二进数可以表示2=21个英文字母
，两位二进制数可以表示4=22个英文字母，……，n 位二进制数可以表示2n个英文字母。如果规定，可以 用1位二进制数表示英文字母，也可以用两位二进制数 表示英文字母。
4.6 树
定理 在完全m叉树中，其树叶数为t，分枝点数为i，则 (m1)*i=t-1。 证明：
ch04不定期船
13
航次估算(Voyage Estimate)，就是根据各待选航
次的货运量、运费率、航线及船舶本身的有关资料以
及港口使费和燃油价格，估算各航次的收入、成本、
每天净收益及其它经济指标。 通过航次估算，船东可以预知某个航次是否盈利； 而且经过各个航次之间的航次估算结果的对比，能够 使船舶经营人找出盈利最好、最合适的航次。
d d海 ( 海 淡 ) / 淡
(5)注意货物的积载因数。
17
5、航次费用的估算
航次费用是随航次的不同而不同的，它是可变 成本，主要包括：燃料费、港口使费、货物装卸费、 运河费、额外保险费以及其它费用。
18
6、盈利性分析
航次盈利指标的计算按下面公式进行： 航次总收入 航次净收入
解：
42
43
例3：一艘载重吨为44600吨的干散货船，预计年船舶 资本成本和经营费用的分摊额为1168000美元，全年营运 11.5个月。该船航速每小时14.5海里，及在此航速下主机 耗油量每天重油是42吨，辅机用轻柴油每天２吨，当时 市场油价是，重油每吨85美元，轻柴油每吨120美元。在 S港卸完货物时从经纪人处传来两个租船机会： 机会１：程租。见例1
前者以月计算，不问月大小，仅在租费期间不到一个
月时，才以30天作为一个月按比例计算，而后者仅按实际 天数计算。两种方法可以互相换算。
期租租船价可分为成本基价(Hire Base，H/B)和赢利
基价(charter Base，C/B)两种，用这两种基价，可以使
船舶所有人估算期租经营的盈亏，并将其作为选择期租的
= 9321 （美元）> 0
答：船东执行该合同是赢的。
32
第四章 不定期船运输
Ch04螺纹联接及螺纹传动-4
螺杆直径和长度、螺距、螺旋线头数、螺母高度。 5、螺纹公差的确定 6、螺旋副零件与滑板联接结构的确定
主要有刚性、弹性和活动联接结构。
三、滑动螺旋传动设计 1、滑动螺旋副的材料和结构
（1）滑动螺旋副的材料 （常用材料见表4-10） 1） 螺杆的材料应具有足够的强度和耐磨性，良好的可加工 性，对于精密传动螺旋，还要求在热处理后有较好的尺寸稳 定性。 2）螺母的材料除要求具有足够的强度外，还要求与螺杆配合 传动时摩擦因数小和耐磨性好，抗胶合能力强。 螺杆的材料：常用35、45号钢;需经热处理以达到高硬度的重 要螺杆，常用合金钢，如65Mn、40Cr、T12、20CrMnTi等。 螺母材料：常用材料有铸造青铜，如ZCuSn10Pb1, ZCuSn5Pb5Zn5；重载低速使用强度较高的铸造青铜ZCuAl10Fe3 或铸造黄铜ZCuZn25Al6Fe3Mn3 ；低速不重要的螺旋传动也可 用耐磨铸铁或灰铸铁。
螺 母
ZcuAl9Fe4Ni4 Mn2 ZCuZn25Al6Fe 3Mn3
注意：①要求强度耐磨性高，配对后f小，加工性好。 ②螺杆硬度高于螺母 （2）滑动螺旋副的结构
滑动螺旋副的结构主要是指螺杆、螺母的固定和支承的结构 形式。螺旋传动的工作刚度与精度等和支承结构有直接关系。
滑动螺旋传动采用梯形、矩形或锯齿形螺纹（多用梯形螺 纹,重载起重螺旋可用锯齿形螺纹, 对效率要求高时可用矩形 螺纹）。 螺母结构： 1）整体式——结构简单，但磨损后精度较差。 2）组合式——磨损后可补偿间隙、精度较高。 3）开合式——适合于双向传动，可提高传动精 度，消除空回误差。
螺距
F F FP p [ p] A d 2 h z d 2 h H
承载螺纹的圈数 一圈螺纹的承载面积
ch04 国际经济学课后答案与习题(萨尔瓦多)
*CHAPTER 4(Core Chapter)THE HECKSCHER-OHLIN AND OTHER TRADE THEORIESOUTLINE4.1 Introduction4.2 Factor Endowments and the Heckscher-Ohlin Theory4.3 The Formal Heckscher-Ohlin ModelCase Study 4-1 The Revealed Comparative Advantage of Various Countries and Regions4.4 Factor-Price Equalization and Income DistributionCase Study 4-2 Has International Trade Increased U.S. Wage Inequalities?4.5 Empirical Tests of the Heckscher-Ohlin Theory4.6 Economies of Scale and International TradeCase Study 4-3 The New International Economies of Scale4.7 Trade Based on Product DifferentiationCase Study 4-4 Growth of Intra-Industry Trade4.8 Technological Gap and Product Cycle ModelsCase Study 4-5: The United States as the Most Competitive Economy in the World4.9 Transportation Costs and International Trade4.10 Environmental Standards and International TradeAppendix The Specific-Factors Model and Intra-Industry Trade ModelsA4.1 The Specific-Factors ModelA4.2 A Model of Intra-Industry TradeKey TermsInternationalofscaleeconomies pricesRelativefactorproducts Heckscher–Ohlin (H–O) theory DifferentiatedtradeIntra-industryHeckscher–Ohlintheorem(H–O)Factor-proportions or factor-endowment theory Technological gap modelcyclemodelProductFactor–price equalization theoremcostsTransportationStolper-Samuelsontheoremmodel Nontraded goods and services Specific-factorsparadox Environmental standardsLeontiefMonopolisticcompetitionscalereturnsIncreasingtoLecture Guide1. This is one of the most important and difficult chapters in the book. It is also a long chapter andrequires four lectures to cover adequately.2. In the first lecture, I would cover sections 1-3. Section 3 is one of the most important sections inthe book because it presents the H-O model. I would proceed slowly and carefully in explaining Figure 4.1 and compare it to the standard trade model of Figure 3.4.3. In the second lecture, I would cover sections 4 and 5. Section 4 on the factor-price equalizationtheorem and income distribution is a difficult section. Case Study 4-2 should be of great interest to the students and give rise to a great deal of class discussion.4. In third lecture, I would cover sections sections 6-7, paying a great deal of attention to section 7on trade in differentiated products.5. In fourth lecture, I would cover the rest of the chapter.Answers to Review Questions and Problems1. a. The Heckscher–Ohlin (H-0) theorem postulates that a nation will export those commodi- ties whose production requires the intensive use of the nation’s relatively abundant and cheap factor and import the commodities whose production requires the intensive useof the nation’s relatively scarce and expensive factor. In short, the relatively labor-richnation exports relatively labor-intensive commodities and imports the relativelycapital-intensive commodities.b. Heckscher and Ohlin identify the relative difference in factor endowments amongnations as the basic determinant of comparative advantage and international trade.c. The H-O Theory represent an extension of the standard trade model because it explains the basis for comparative advantage (classical economists, such as Ricardo had assumed it) and examines the effect of international trade on factor prices and income distribution (which classical economists had left unanswered).2. See Figure 1 on the next page.3. a. The factor–price equalization theorem postulates that international trade will bring about the equalization of the returns to homogeneous or identical factors across nations.b. The Stopler-Samuelson theorem postulates that free international trade reduces the realincome of the nation’s relatively scarce factor and increases the real income of the nation’s relatively abundant factor.Fig 4.1Fig 4.2XXb. The specific-factors model postulates that the opening of trade (1) benefits the specific factorused in the production of the nation’s export commodity, (2) harms the specific factor used in the production of the nation’s import-competing industry, and (3) leads to an ambiguouseffect (i.e., it may benefit or harm) the mobile factor.c. Trade acts as a substitute for the international mobility of factors of production in itseffect on factor prices. With perfect mobility, labor would migrate from the low-wagenation to the high-wage nation until wages in the two nations are equalized. Similarly,capital would move from the low-interest to the high-interest nation until the rate ofinterest was equalized in the two nations.4. a. The Leontief paradox refers to the original Leontief’s finding that U.S. import substituteswere more K-intensive than U.S. exports. This was the opposite of what the H-O theorempostulated.b. The Leontief paradox was resolved by including human capital into the calculations andexcluding industries based on natural resources. Recent research using data on many sectors, for many countries, over many years, and considering that countries could specialize in aparticular subset or group of commodities that were best suited to their specific factorendowments, provides strong support for the H-O theorem.c. The Hecksher-Olhin theory remains the centerpiece of modern trade theory for explaininginternational trade today. To be sure, there are other forces (such as economies of scale,product differentiation, and technological differences across countries) that provide additional reasons and explanations for some international trade not explained by the basic H-O model.These other trade theories complement the basic H-O model in explaining the pattern ofinternational trade in the world today.5. International trade with developing economies, especially newly industrializing economies (NIEs), contributed in two ways to increased wage inequalities between skilled and unskilled workers in the United States during the past two decades. Directly, by reducing the demand for unskilledworkers as a result of increased U.S. imports of labor-intensive manufactures and, indirectly, byspeeding up the introduction of labor-saving innovations, which further reduced the U.S.demand for unskilled workers. International trade, however, was only a small cause of increased wage inequalities in the United States. The most important cause was technological change.6. a. Economies of scale refer to the production situation where output grows proportionatelymore than the increase in inputs or factors of production. For example, output may morethan double with a doubling of inputs.b. Even if two nations were identical in every respect, there is still a basis for mutually bene-ficial trade based on economies of scale. When each nation specializes in the production of one commodity, the combined total world output of both commodities will be greater thanthan without specialization when economies of scale are present. With trade, each nationthen shares in these gains.c. The new international economies of scale refers to the increase in productivity resultingfrom firms purchasing parts and components from nations where they are made cheaperand better, and by establishing production facilities abroad-26-7. a. Product differentiation refers to products that are similar, but not identical. Intra-industrytrade refers to trade in differentiated products, as opposed to inter-industry trade incompletely different products.b. Intra-industry trade arises in order to take advantage of important economies of scale inproduction. That is, with intra-industry trade each firm or plant in industrial countries canspecialize in the production of only one, or at most a few, varieties and styles of the sameproduct rather than many different varieties and styles of a product and achieve economies of scale.c. With few varieties and styles, more specialized and faster machinery can be developedfor a continuous operation and a longer production run. The nation then imports othervarieties and styles from other nations. Intra-industry trade benefits consumers because ofthe wider range of choices (i.e., the greater variety of differentiated products) available atthe lower prices made possible by economies of scale in production.8. a. According to the technological gap model, a firm exports a new product until imitators incountries take away its market. In the meantime, the innovating firm will have introduced a new product or process.b. The criticism of the technological gap model are that it does not explain the size of techno- logical gaps and does not explore the reason for technological gaps arising in the first place, or exactly how they are eliminated over time.c. The five stages of the product cycle model are: the introduction of the product, expansion of production for export, standardization and beginning of production abroad through imitation, foreign imitators underselling the nation in third markets, and foreigners underselling theinnovating firms in their home market as well.9. See Figure 2 on page 25.10. A nation with lower environmental standards can use the environment as a resource endow-ment or as a factor of production in attracting polluting firms from abroad and achieving acomparative advantage in the production of polluting goods and services. This can lead totrade disputes with nations with more stringent environmental standards.-27-Multiple-Choice Questions1. The H-O model extends the classical trade model by:a. explaining the basis for comparative advantageb. examining the effect of trade on factor prices*c. both a and bd. neither a nor b2. A nation is said to have a relative abundance of K if it has a:a. greater absolute amount of Kb. smaller absolute amount of Lc. higher L/K ratio*d. lower price of K in relation to the price of L3. A difference in relative commodity prices between nations can be based on a difference in:a. technologyb. factor endowmentsc. tastes*d. all of the above4. In the H-O model, international trade is based mostly on a difference in:a. technology*b. factor endowmentsc. economies of scaled. tastes5. According to the H-O theory, trade reduces international differences in:a. commodity pricesb. in factor prices*c. both commodity and factor pricesd. neither relative nor absolute factor prices6. According to the Stolper-Samuelson theorem, international trade leads toa. reduction in the real income of the nation’s relatively abundant factor*b. reduction in the real income of the nation’s relatively scarce factorc. increase in the real income of the nation’s relatively scarce factord. none of the above7. Which of the following is false with regard to the specific factors theorem, international trade *a. harms the immobile factors that are specific to the nation’s export commodities or sectorsb. harms the immobile factors that are specific to the nation’s import-competing commoditiesc. has an ambiguous effect on the nation’s mobile factorsd. may benefit or harm the nation’s mobile factors8. Perfect international mobility of factors of productiona. leads to a reduction in international differences in the returns to homogenous factorsb. acts as a substitute for international trade in its effects on factor pricesc. operates on the supply of factors in affecting factor prices*d. all of the above9. The Leontief paradox refers to the empirical finding that U.S.*a. import substitutes were more K-intensive than exportsb. exports were more L-intensive than importsc. exports were more K-intensive than import substitutesd. all of the above10. From empirical studies, we conclude that the H-O theory:a. must be rejectedb. must be accepted without reservations*c. can generally be acceptedd. explains all international trade11. International trade can be based on economies of scale even if both nations have identical:a. factor endowmentsb. tastesc. technology*d. all of the above12. A great deal of international trade:a. is intra-industry tradeb. involves differentiated productsc. is based on monopolistic competition*d. all of the above13. Intra-industry trade takes place:a. because products are homogeneous*b. in order to take advantage of economies of scalec. because perfect competition is the prevalent form of market organizationd. all of the above14. Which of the following statements is true with regard to the product-cycle theory?a. it depends on differences in technological changes over time among countriesb. it depends on the opening and the closing of technological gaps among countriesc. it postulates that industrial countries export more advanced products to lessadvanced countries*d. all of the above15. Transport costs:a. increase the price in the importing countryb. reduces the price in the exporting countryc. falls less heavily on the nation with the more elastic demand and supply curves of the traded commodity*d. all of the above-30-ADDITIONAL ESSAYS AND PROBLEMS FOR PART ONE1. Assume that both the United States and Germany produce beef and computer chips with the following costs:United States Germany(dollars) (marks)Unit cost of beef (B) 2 8Unit cost of computer chips (C) 1 2(a) What is the opportunity cost of beef (B) and computer chips (C) in each country?(b) In which commodity does the United States have a comparative cost advantage?What about Germany?(c) What is the range for mutually beneficial trade between the United States and Germanyfor each computer chip traded?(b) How much would the United States and Germany gain if 1 unit of beef is exchangedfor 3 chips?Answ. (a) In the United States:the opportunity cost of one unit of beef is 2 chips;the opportunity cost of one chip is 1/2 unit of beef.In Germany:the opportunity cost of one unit of beef is 4 chips;the opportunity cost of one chip is 1/4 unit of beef.(b) The United States has a comparative cost advantage in beef with respect to Germany,while Germany has a comparative cost advantage in computer chips.(c) The range for mutually beneficial trade between the United States and Germany foreach unit of beef that the United States exports is2C < 1B < 4C(d) Both the United States and Germany would gain 1 chip for each unit of beef traded.2. Given: (1) two nations (1 and 2) which have the same technology but different factor costs conditions, and (3) no transportation costs, tariffs, or other obstructions to trade.Prove geometrically that mutually advantageous trade between the two nations is possible.Note: Your answer should show the autarky (no-trade) and free-trade points of production and consumption for each nation, the gains from trade of each nation, and express the equilibrium condition that should prevail when trade stops expanding.)Ans.: See the figure below.Fig 4.3Fig 4.4Nations 1 and 2 have different production possibilities curves and different community indifference maps. With these, they will usually end up with different relative commodity prices in autarky, thus making mutually beneficial trade possible.In the figure, Nation 1 produces and consumes at point A and Px/Py=P A in autarky, while Nation 2 produces and consumes at point A' and Px/Py=P A'. Since P A < P A', Nation 1 has a comparative advantage in X and Nation 2 in Y. Specialization in production proceeds until point B in Nation 1 and point B' in Nation 2, at which P B =P B' and the quantity supplied for export of each commodity exactly equals the quantity demanded for import.Thus, Nation 1 starts at point A in production and consumption in autarky, moves to point B in production, and by exchanging BC of X for CE of Y reaches point E in consumption. E > A since it involves more of both X and Y and lies on a higher community indifference curve.Nation 2 starts at A' in production and consumption in autarky, moves to point B' in production, and by exchanging B'C' of Y for C'E' of X reaches point E'in consumption (which exceeds A').At Px/Py=P B =P B', Nation 1 wants to export BC of X for CE of Y, while Nation 2 wants to export B'C' (=CE) of Y for C'E' (=BC) of X. Thus, P B =P B' is the equilibrium relative commodity price because it clears both (the X and Y) markets.3. (a) Identify the conditions that may give rise to trade between two nations. (b) What aresome of the assumptions on which the Heckscher-Ohlin theory is based? (c) What does this theory say about the pattern of trade and effect of trade on factor prices?Ans. (a) Trade can be based on a difference in factor endowments, technology, or tastesbetween two nations. A difference either in factor endowments or technology results in a different production possibilities frontier for each nation, which, unlessneutralized by a difference in tastes, leads to a difference in relative commodity price and mutually beneficial trade. If two nations face increasing costs and have identical production possibilities frontiers but different tastes, there will also be a differencein relative commodity prices and the basis for mutually beneficial trade between the two nations. The difference in relative commodity prices is then translated into adifference in absolute commodity prices between the two nations, which is the immediate cause of trade.(b) The Heckscher-Ohlin theory (sometimes referred to as the modern theory – asopposed to the classical theory - of international trade) assumes that nations have the same tastes, use the same technology, face constant returns to scale (i.e., a givenpercentage increase in all inputs increases output by the same percentage) but differ widely in factor endowments. It also says that in the face of identical tastes or demand conditions, this difference in factor endowments will result in a difference in relative factor prices between nations, which in turn leads to a difference in relativecommodity prices and trade. Thus, in the Heckscher-Ohlin theory, the internationaldifference in supply conditions alone determines the pattern of trade. To be noted is that the two nations need not be identical in other respects in order for internationaltrade to be based primarily on the difference in their factor endowments.(c) The Heckscher-Ohlin theorem postulates that each nation will export the commodityintensive in its relatively abundant and cheap factor and import the commodityintensive in its relatively scarce and expensive factor. As an important corollary, itadds that under highly restrictive assumptions, trade will completely eliminate thepretrade relative and absolute differences in the price of homogeneous factors amongnations. Under less restrictive and more usual conditions, however, trade will reduce, but not eliminate, the pretrade differences in relative and absolute factor prices among nations. In any event, the Heckscher-Ohlin theory does say something very useful onhow trade affects factor prices and the distribution of income in each nation. Classical economists were practically silent on this point.-33-4. Suppose that tastes change in Nation 1 (the L-abundant and L-cheap nation) so that consumers demand more of commodity X (the L-intensive commodity) and less of commodity Y (the K- intensive commodity). Suppose that Nation 1 is India, commodity X is textiles, and commodi- ty Y is food. Starting from the no-trade equilibrium position and using the Heckscher-Ohlinmodel, trace the effect of this change in tastes on India's (a) relative commodity prices anddemand for food and textiles, (b) production of both commodities and factor prices, and(c) comparative advantage and volume of trade. (d) Do you expect international trade to leadto the complete equalization of relative commodity and factor prices between India and theUnited States? Why?Ans. (a) The change in tastes can be visualized by a shift toward the textile axis in India'sindifference map in such a way that an indifference curve is tangent to the steepersegment of India's production frontier (because of increasing opportunity costs) after the increase in demand for textiles. This will cause the pretrade relative commodity price of textiles to rise in India.(b) The increase in the relative price of textiles will lead domestic producers in India toshift labor and capital from the production of food to the production of textiles. Since textiles are L-intensive in relation to food, the demand for labor and therefore the wage rate will rise in India. At the same time, as the demand for food falls, thedemand for and thus the price of capital will fall. With labor becoming relative more expensive, producers in India will substitute capital for labor in the production of both textiles and food.(c) Even with the rise in relative wages and in the relative price of textiles, India stillremains the L-abundant and low-wage nation with respect to a nation such as theUnited States. However, the pretrade difference in the relative price of textilesbetween India and the United States is now somewhat smaller than before the change in tastes in India. As a result the volume of trade required to equalize relativecommodity prices and hence factor prices is smaller than before. That is, India need now export a smaller quantity of textiles and import less food than before for therelative price of textiles in India and the United States to be equalized. Similarly, the gap between real wages and between India and the United States is now smaller and can be more quickly and easily closed (i.e., with a smaller volume of trade).(d) Since many of the assumptions required for the complete equalization of relativecommodity and factor prices do not hold in the real world, great differences can be expected and do in fact remain between real wages in India and the United States.Nevertheless, trade would tend to reduce these differences, and the H-O model does identify the forces that must be considered to analyze the effect of trade on thedifferences in the relative and absolute commodity and factor prices between Indiaand the United States.-34-5. (a) Explain why the Heckscher-Ohlin trade model needs to be extended. (b) Indicate in what important ways the Heckscher-Ohlin trade model can be extended. (c) Explain what ismeant by differentiated products and intra-industry trade.Ans. (a) The Heckscher-Ohlin trade model needs to be extended because, while generallycorrect, it fails to explain a significant portion of international trade, particularly the trade in manufactured products among industrial nations.(b) The international trade left unexplained by the basic Heckscher-Ohlin trade model canbe explained by (1) economies of scale, (2) intra-industry trade, and (3) trade based on imitation gaps and product differentiation.(c) Differentiated products refer to similar, but not identical, products (such as cars,typewriters, cigarettes, soaps, and so on) produced by the same industry or broadproduct group. Intra-industry trade refers to the international trade in differentiated products.-35-。
ch04国际经济学课后答案与习题（萨尔瓦多）
ch04国际经济学课后答案与习题（萨尔⽡多）*CHAPTER 4(Core Chapter)THE HECKSCHER-OHLIN AND OTHER TRADE THEORIESOUTLINE4.1 Introduction4.2 Factor Endowments and the Heckscher-Ohlin Theory4.3 The Formal Heckscher-Ohlin ModelCase Study 4-1 The Revealed Comparative Advantage of Various Countries and Regions4.4 Factor-Price Equalization and Income DistributionCase Study 4-2 Has International Trade Increased U.S. Wage Inequalities?4.5 Empirical Tests of the Heckscher-Ohlin Theory4.6 Economies of Scale and International TradeCase Study 4-3 The New International Economies of Scale4.7 Trade Based on Product DifferentiationCase Study 4-4 Growth of Intra-Industry Trade4.8 Technological Gap and Product Cycle ModelsCase Study 4-5: The United States as the Most Competitive Economy in the World4.9 Transportation Costs and International Trade4.10 Environmental Standards and International TradeAppendix The Specific-Factors Model and Intra-Industry Trade ModelsA4.1 The Specific-Factors ModelA4.2 A Model of Intra-Industry TradeKey TermsInternationalofscaleeconomies pricesRelativefactorproducts Heckscher–Ohlin (H–O) theory DifferentiatedtradeIntra-industryHeckscher–Ohlintheorem(H–O)Factor-proportions or factor-endowment theory Technological gap modelcyclemodelProductFactor–price equalization theoremcostsTransportationStolper-Samuelsontheoremmodel Nontraded goods and services Specific-factorsparadox Environmental standardsLeontiefMonopolisticcompetitionscalereturnsIncreasingtoLecture Guide1. This is one of the most important and difficult chapters in the book. It is also a long chapter andrequires four lectures to cover adequately.2. In the first lecture, I would cover sections 1-3. Section 3 is one of the most important sections inthe book because it presents the H-O model. I would proceed slowly and carefully in explaining Figure 4.1 and compare it to the standard trade model of Figure 3.4.3. In the second lecture, I would cover sections 4 and 5. Section 4 on the factor-price equalizationtheorem and income distribution is a difficult section. Case Study 4-2 should be of great interest to the students and give rise to a great deal of class discussion.4. In third lecture, I would cover sections sections 6-7, paying a great deal of attention to section 7on trade in differentiated products.5. In fourth lecture, I would cover the rest of the chapter.Answers to Review Questions and Problems1. a. The Heckscher–Ohlin (H-0) theorem postulates that a nation will export those commodi- ties whose production requires the intensive use of the nation’s relatively abundant and cheap factor and import the commodities whose production requires the intensive useof the nation’s relatively scarce and expensive factor. In short, the relatively labor-richnation exports relatively labor-intensive commodities and imports the relativelycapital-intensive commodities.b. Heckscher and Ohlin identify the relative difference in factor endowments amongnations as the basic determinant of comparative advantage and international trade.c. The H-O Theory represent an extension of the standard trade model because it explains the basis for comparative advantage (classical economists, such as Ricardo had assumed it) and examines the effect of international trade on factor prices and income distribution (which classical economists had left unanswered).2. See Figure 1 on the next page.3. a. The factor–price equalization theorem postulates that international trade will bring about the equalization of the returns to homogeneous or identical factors across nations.b. The Stopler-Samuelson theorem postulates that free international trade reduces the realincome of the nation’s relatively scarce factor and increases the real income of the nation’s relatively abundant factor.Fig 4.1Fig 4.2XXb. The specific-factors model postulates that the opening of trade (1) benefits the specific factorused in the production of the nation’s export commodity, (2) harms the specific factor used in the production of the nation’s import-competing industry, and (3) leads to an ambiguouseffect (i.e., it may benefit or harm) the mobile factor.c. Trade acts as a substitute for the international mobility of factors of production in itseffect on factor prices. With perfect mobility, labor would migrate from the low-wagenation to the high-wage nation until wages in the two nations are equalized. Similarly,capital would move from the low-interest to the high-interest nation until the rate ofinterest was equalized in the two nations.4. a. The Leontief paradox refers to the original Leontief’s finding that U.S. import substituteswere more K-intensive than U.S. exports. This was the opposite of what the H-O theorempostulated.b. The Leontief paradox was resolved by including human capital into the calculations andexcluding industries based on natural resources. Recent research using data on many sectors, for many countries, over many years, and considering that countries could specialize in aparticular subset or group of commodities that were best suited to their specific factorendowments, provides strong support for the H-O theorem.c. The Hecksher-Olhin theory remains the centerpiece of modern trade theory for explaininginternational trade today. To be sure, there are other forces (such as economies of scale,product differentiation, and technological differences across countries) that provide additional reasons and explanations for some international trade not explained by the basic H-O model.These other trade theories complement the basic H-O model in explaining the pattern ofinternational trade in the world today.5. International trade with developing economies, especially newly industrializing economies (NIEs), contributed in two ways to increased wage inequalities between skilled and unskilled workers in the United States during the past two decades. Directly, by reducing the demand for unskilledworkers as a result of increased U.S. imports of labor-intensive manufactures and, indirectly, byspeeding up the introduction of labor-saving innovations, which further reduced the U.S.demand for unskilled workers. International trade, however, was only a small cause of increased wage inequalities in the United States. The most important cause was technological change.6. a. Economies of scale refer to the production situation where output grows proportionatelymore than the increase in inputs or factors of production. For example, output may morethan double with a doubling of inputs.b. Even if two nations were identical in every respect, there is still a basis for mutually bene-ficial trade based on economies of scale. When each nation specializes in the production of one commodity, the combined total world output of both commodities will be greater thanthan without specialization when economies of scale are present. With trade, each nationthen shares in these gains.c. The new international economies of scale refers to the increase in productivity resultingfrom firms purchasing parts and components from nations where they are made cheaperand better, and by establishing production facilities abroad-26-7. a. Product differentiation refers to products that are similar, but not identical. Intra-industrytrade refers to trade in differentiated products, as opposed to inter-industry trade incompletely different products.b. Intra-industry trade arises in order to take advantage of important economies of scale inproduction. That is, with intra-industry trade each firm or plant in industrial countries canspecialize in the production of only one, or at most a few, varieties and styles of the sameproduct rather than many different varieties and styles of a product and achieve economies of scale.c. With few varieties and styles, more specialized and faster machinery can be developedfor a continuous operation and a longer production run. The nation then imports othervarieties and styles from other nations. Intra-industry trade benefits consumers because ofthe wider range of choices (i.e., the greater variety of differentiated products) available atthe lower prices made possible by economies of scale in production.8. a. According to the technological gap model, a firm exports a new product until imitators incountries take away its market. In the meantime, the innovating firm will have introduced a new product or process. b. The criticism of the technological gap model are that it does not explain the size of techno- logical gaps and does not explore the reason for technological gaps arising in the first place, or exactly how they are eliminated over time.c. The five stages of the product cycle model are: the introduction of the product, expansion of production for export, standardization and beginning of production abroad through imitation, foreign imitators underselling the nation in third markets, and foreigners underselling theinnovating firms in their home market as well.9. See Figure 2 on page 25.10. A nation with lower environmental standards can use the environment as a resource endow-ment or as a factor of production in attracting polluting firms from abroad and achieving acomparative advantage in the production of polluting goods and services. This can lead totrade disputes with nations with more stringent environmental standards.-27-Multiple-Choice Questions1. The H-O model extends the classical trade model by:a. explaining the basis for comparative advantageb. examining the effect of trade on factor prices*c. both a and bd. neither a nor b2. A nation is said to have a relative abundance of K if it has a:a. greater absolute amount of Kb. smaller absolute amount of Lc. higher L/K ratio*d. lower price of K in relation to the price of L3. A difference in relative commodity prices between nations can be based on a difference in:a. technologyb. factor endowmentsc. tastes*d. all of the above4. In the H-O model, international trade is based mostly on a difference in:a. technology*b. factor endowmentsc. economies of scaled. tastes5. According to the H-O theory, trade reduces international differences in:a. commodity pricesb. in factor prices*c. both commodity and factor pricesd. neither relative nor absolute factor prices6. According to the Stolper-Samuelson theorem, international trade leads toa. reduction in the real income of the nation’s relatively abundant factor*b. reduction in the real income of the nation’s relatively scarce factorc. increase in the real income of the nation’s relatively scarce factord. none of the above7. Which of the following is false with regard to the specific factors theorem, international trade *a. harms the immobile factors that are specific to the nation’s export commodities or sectorsb. harms the immobile factors that are specific to the nation’s import-competing commoditiesc. has an ambiguous effect on the nation’s mobile factorsd. may benefit or harm the nation’s mobile factors8. Perfect international mobility of factors of productiona. leads to a reduction in international differences in the returns to homogenous factorsb. acts as a substitute for international trade in its effects on factor pricesc. operates on the supply of factors in affecting factor prices*d. all of the above9. The Leontief paradox refers to the empirical finding that U.S.*a. import substitutes were more K-intensive than exportsb. exports were more L-intensive than importsc. exports were more K-intensive than import substitutesd. all of the above10. From empirical studies, we conclude that the H-O theory:a. must be rejectedb. must be accepted without reservations*c. can generally be acceptedd. explains all international trade11. International trade can be based on economies of scale even if both nations have identical:a. factor endowmentsb. tastesc. technology*d. all of the above12. A great deal of international trade:a. is intra-industry tradeb. involves differentiated productsc. is based on monopolistic competition*d. all of the above13. Intra-industry trade takes place:a. because products are homogeneous*b. in order to take advantage of economies of scalec. because perfect competition is the prevalent form of market organizationd. all of the above14. Which of the following statements is true with regard to the product-cycle theory?a. it depends on differences in technological changes over time among countriesb. it depends on the opening and the closing of technological gaps among countriesc. it postulates that industrial countries export more advanced products to lessadvanced countries*d. all of the above15. Transport costs:a. increase the price in the importing countryb. reduces the price in the exporting countryc. falls less heavily on the nation with the more elastic demand and supply curves of the traded commodity*d. all of the above-30-ADDITIONAL ESSAYS AND PROBLEMS FOR PART ONE1. Assume that both the United States and Germany produce beef and computer chips with the following costs: United States Germany(dollars) (marks)Unit cost of beef (B) 2 8Unit cost of computer chips (C) 1 2(a) What is the opportunity cost of beef (B) and computer chips (C) in each country?(b) In which commodity does the United States have a comparative cost advantage?What about Germany?(c) What is the range for mutually beneficial trade between the United States and Germanyfor each computer chip traded?(b) How much would the United States and Germany gain if 1 unit of beef is exchangedfor 3 chips?Answ. (a) In the United States:the opportunity cost of one unit of beef is 2 chips;the opportunity cost of one chip is 1/2 unit of beef.In Germany:the opportunity cost of one unit of beef is 4 chips;the opportunity cost of one chip is 1/4 unit of beef.(b) The United States has a comparative cost advantage in beef with respect to Germany,while Germany has a comparative cost advantage in computer chips.(c) The range for mutually beneficial trade between the United States and Germany foreach unit of beef that the United States exports is2C < 1B < 4C(d) Both the United States and Germany would gain 1 chip for each unit of beef traded.2. Given: (1) two nations (1 and 2) which have the same technology but different factor costs conditions, and (3) no transportation costs, tariffs, or other obstructions to trade.Prove geometrically that mutually advantageous trade between the two nations is possible.Note: Your answer should show the autarky (no-trade) and free-trade points of production and consumption for each nation, the gains from trade of each nation, and express the equilibrium condition that should prevail when trade stops expanding.) Ans.: See the figure below.Fig 4.3Fig 4.4Nations 1 and 2 have different production possibilities curves and different community indifference maps. With these, they will usually end up with different relative commodity prices in autarky, thus making mutually beneficial trade possible.In the figure, Nation 1 produces and consumes at point A and Px/Py=P A in autarky, while Nation 2 produces and consumes at point A' and Px/Py=P A'. Since P A < P A', Nation 1 has a comparative advantage in X and Nation 2 in Y. Specialization in production proceeds until point B in Nation 1 and point B' in Nation 2, at which P B =P B' and the quantity supplied for export of each commodity exactly equals the quantity demanded for import.Thus, Nation 1 starts at point A in production and consumption in autarky, moves to point B in production, and by exchanging BC of X for CE of Y reaches point E in consumption. E > A since it involves more of both X and Y and lies on a higher community indifference curve.Nation 2 starts at A' in production and consumption in autarky, moves to point B' in production, and by exchanging B'C' of Y for C'E' of X reaches point E'in consumption (which exceeds A').At Px/Py=P B =P B', Nation 1 wants to export BC of X for CE of Y, while Nation 2 wants to export B'C' (=CE) of Y for C'E' (=BC) of X. Thus, P B =P B' is the equilibrium relative commodity price because it clears both (the X and Y) markets.3. (a) Identify the conditions that may give rise to trade between two nations. (b) What aresome of the assumptions on which the Heckscher-Ohlin theory is based? (c) What does this theory say about the pattern of trade and effect of trade on factor prices?Ans. (a) Trade can be based on a difference in factor endowments, technology, or tastesbetween two nations. A difference either in factor endowments or technology results in a different production possibilities frontier for each nation, which, unlessneutralized by a difference in tastes, leads to a difference in relative commodity price and mutually beneficial trade. If two nations face increasing costs and have identical production possibilities frontiers but different tastes, there will also be a differencein relative commodity prices and the basis for mutually beneficial trade between the two nations. The difference in relative commodity prices is then translated into adifference in absolute commodity prices between the two nations, which is the immediate cause of trade.(b) The Heckscher-Ohlin theory (sometimes referred to as the modern theory – asopposed to the classical theory - of international trade) assumes that nations have the same tastes, use the same technology, face constant returns to scale (i.e., a givenpercentage increase in all inputs increases output by the same percentage) but differ widely in factor endowments. It also says that in the face of identical tastes or demand conditions, this difference in factor endowments will result in a difference in relative factor prices between nations, which in turn leads to a difference in relativecommodity prices and trade. Thus, in the Heckscher-Ohlin theory, the internationaldifference in supply conditions alone determines the pattern of trade. To be noted is that the two nations need not be identical in other respects in order for internationaltrade to be based primarily on the difference in their factor endowments.(c) The Heckscher-Ohlin theorem postulates that each nation will export the commodityintensive in its relatively abundant and cheap factor and import the commodityintensive in its relatively scarce and expensive factor. As an important corollary, itadds that under highly restrictive assumptions, trade will completely eliminate thepretrade relative and absolute differences in the price of homogeneous factors amongnations. Under less restrictive and more usual conditions, however, trade will reduce, but not eliminate, the pretrade differences in relative and absolute factor prices among nations. In any event, the Heckscher-Ohlin theory does say something very useful onhow trade affects factor prices and the distribution of income in each nation. Classical economists were practically silent on this point.4. Suppose that tastes change in Nation 1 (the L-abundant and L-cheap nation) so that consumers demand more of commodity X (the L-intensive commodity) and less of commodity Y (the K- intensive commodity). Suppose that Nation 1 is India, commodity X is textiles, and commodi- ty Y is food. Starting from the no-trade equilibrium position and using the Heckscher-Ohlinmodel, trace the effect of this change in tastes on India's (a) relative commodity prices anddemand for food and textiles, (b) production of both commodities and factor prices, and(c) comparative advantage and volume of trade. (d) Do you expect international trade to leadto the complete equalization of relative commodity and factor prices between India and theUnited States? Why?Ans. (a) The change in tastes can be visualized by a shift toward the textile axis in India'sindifference map in such a way that an indifference curve is tangent to the steepersegment of India's production frontier (because of increasing opportunity costs) after the increase in demand for textiles. This will cause the pretrade relative commodity price of textiles to rise in India.(b) The increase in the relative price of textiles will lead domestic producers in India toshift labor and capital from the production of food to the production of textiles. Since textiles are L-intensive in relation to food, the demand for labor and therefore the wage rate will rise in India. At the same time, as the demand for food falls, thedemand for and thus the price of capital will fall. With labor becoming relative more expensive, producers in India will substitute capital for labor in the production of both textiles and food.(c) Even with the rise in relative wages and in the relative price of textiles, India stillremains the L-abundant and low-wage nation with respect to a nation such as theUnited States. However, the pretrade difference in the relative price of textilesbetween India and the United States is now somewhat smaller than before the change in tastes in India. As a result the volume of trade required to equalize relativecommodity prices and hence factor prices is smaller than before. That is, India need now export a smaller quantity of textiles and import less food than before for therelative price of textiles in India and the United States to be equalized. Similarly, the gap between real wages and between India and the United States is now smaller and can be more quickly and easily closed (i.e., with a smaller volume of trade).(d) Since many of the assumptions required for the complete equalization of relativecommodity and factor prices do not hold in the real world, great differences can be expected and do in fact remain between real wages in India and the United States.Nevertheless, trade would tend to reduce these differences, and the H-O model does identify the forces that must be considered to analyze the effect of trade on thedifferences in the relative and absolute commodity and factor prices between Indiaand the United States.5. (a) Explain why the Heckscher-Ohlin trade model needs to be extended. (b) Indicate in what important ways the Heckscher-Ohlin trade model can be extended. (c) Explain what ismeant by differentiated products and intra-industry trade.Ans. (a) The Heckscher-Ohlin trade model needs to be extended because, while generallycorrect, it fails to explain a significant portion of international trade, particularly the trade in manufactured products among industrial nations.(b) The international trade left unexplained by the basic Heckscher-Ohlin trade model canbe explained by (1) economies of scale, (2) intra-industry trade, and (3) trade based on imitation gaps and product differentiation.(c) Differentiated products refer to similar, but not identical, products (such as cars,typewriters, cigarettes, soaps, and so on) produced by the same industry or broadproduct group. Intra-industry trade refers to the international trade in differentiated products.。
Ch04罪犯劳动管理的特点及其岗位要求(精)
学习任务一 学习任务二 学习任务三
罪犯动管理对象的特点 罪犯劳动管理岗位的职责 罪犯劳动管理岗位的要求
主讲人：程玉敏
副教授
一、罪犯劳动管理对象的特点
（一）当前在押犯成分多元化 20世纪80、90年代罪犯构成特点： “三盲”（文盲、法盲、和 流氓）， “三多”（贫者多、青年多、短期多），“三化” （低文化、低龄化、农村化）。 现在罪犯构成特点： 从罪犯案情上看，暴力加剧，作案手段残暴；团伙罪犯、涉黑涉恶 突出；邪教组织漫延，毒品犯罪严重。 从罪犯的文化、年龄、住地、职业看，文化程度高，年龄大，智能 型犯罪和职业犯罪相对增多。 从罪犯刑期看，刑期长、二进宫以上累犯、团伙犯增多。 这些构成变化使改造对象自身的心态、思想、行为向畸形冲动恶 变，具有极强报复性、突发性、纠合性、欺骗性和两面性，改造 难度加大，安全隐患较多。
(五)劳动力队伍极不稳定
1．劳动力数量、质量不稳定。 2．劳动力熟练程度和操作技术上的不稳定性。
学习任务二 罪犯劳动管理岗位的职责
“把墙内的人改造好，让墙外的人生活好， 这就是我们的职责” ——梅州监狱警察
监狱人民警察职权的内容
1.执行刑罚权 2.管理监狱权
收监权。 警戒隔离带的设置权。 戒具使用权。 武器使用权。 罪犯来往信件检查权。 对罪犯的考核权。 对罪犯的行政奖惩权。
(四)劳动力结构不合理 社会普通企业是围绕生产配置劳动力的，随时可以根据 企业的生产经营需要对劳动力结构进行调整，以确保其 合理性。
监狱的生产劳动是围绕执行刑罚，惩罚与改造罪犯这个 职能组织的。监狱生产的劳动力来源完全由社会打击犯 罪情况决定。
劳动力结构由监狱收押的罪犯结构决定。监狱劳动力思 想行为结构、数量质量结构、文化技术结构，年龄结构， 性格气质结构不可能按一般生产劳动需要进行主动的科 学配置，因此呈现不合理状况。
机械制造基础ch04机床基本知识
5 . 按机床主要工作部件的数目可分为：
单轴（single axle） 多轴（multi spindle） 单刀（single-tool） 多刀机床（multi-cutter machine tool）
机床数控化引起机床传统分类方法发生变化， 主要表现在机床品种不是越分越细，而应是趋 向综合。
二、 机床型号编制方法: （regimentation method of machine tool’s model number）
其中：
1）有（ ）的代号或数字，当无内容时则不表示， 若有内容则不带括号；
2）有○符号者，为大写的汉语拼音字母；
3）有△符号者，为阿拉伯数字；
4）有 ○△ 符号者，为大写的汉语拼音字母或者为阿
拉伯数字、或两者兼有之。
通用机床型号辅助部分:
基本部分/ （ Δ ）（- Δ ）
其它特性代号 企业代号
例1： CA6140型卧式车床
2、
联系复合运动之内的各个分解部分，因而传动链所 联系的执行件相互之间的相对速度（相对位移量）有严 格的要求，以保证运动的轨迹。
在内联系传动链中，不应有摩擦传动或是瞬时传动 比变化的传动件（如链传动）。
注：
有几个简单运动就有几个外联系传动链，它们可以有 各自的运动源，也可共用一个运动源。 内联系传动链本身不能提供运动，需要有外联系传动 链将运动源传到内联系传动链上来。 如果外联系传动链与内联系传动链有公用段，内、外传动 链的换置器官（机构）不应布置在公共段。
三、传动原理图
定比机构：传动比固定的传动机构。 换置机构：变换传动比的传动机构。
用一些简明的符号把传动原理和传动路 线表示出来，就是传动原理图。
例：卧式车床的传动原理图
ch04(监测与诊断系统)解读
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B） 放大器和预处理器 放大器和预处理器用来调整由传感器输出的电信号的大小 和输出阻抗等。
C） A／D接口板 A／D接口板主要功能是将信号从连续量变为一个个的离 散数字量。A／D接口板可以同时完成对多路信号的转换(采 样 )。 D）开关量板 用于离散信号。 E）微型计算机 计算机是监测与诊断系统的心脏，负责完成信号的接收、储 存、转换和控制等工作。还可以将信号及分析处理结果显示和 打印出来。
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例2：风机在线监测系统
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《易》曰：天道亏盈而益谦，地道变盈而流谦。
风机一般有大直径的转子，以700一900r／m的转速支承在 结构钢或混凝土地基架座上的轴承中运转。一般，这类风机 的主要故障是由于不均匀的结垢或沉结材料跌落引起的不平 衡和不同轴。其全部特征是在运转频率附近的振动变化。在 这种系统中，为显示轴运动，在各个轴承上装了测振传感器。 用一台双通道电荷故大器对两个传惑器输出信号予以放大。 经滤波器滤波后将信号送入微机系统。 两个轴承的温度监测由铜电阻为敏感元件构成的传感器来 完成。并通过放大器将信号送入微机。微机通过振动信号和 温度信号的变化而识别风机的运转状态。
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F） 磁带记录仪 用磁带记录仪定期到现场记录信号，然后带回来重放并进 行分析。便于离线分析。
G） 示波器
H） 滤波器 由传感器输出的振动信号中包含的频率成分比较复杂，频 率范围也较宽，但有些频率成分是我们不感兴趣的，如高频 噪声干扰信号。因此要用滤波器对传感器输出的信号“过 滤”，除掉一些我们不感兴趣的频率成分，然后送入计算机 处理。
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（2） 数据采集系统的工作步骤 A） 组态 组态即选定被监测对象，选定测点，确定巡检的路线和周期， 确定测量参数，并把这些信息输入计算机。 B） 巡检准备 巡检之前把数据采集系统与计算机联接起来，使用相应的软 件使采集系统处于准备状态，使内存清零，把采集系统的时钟 与计算机时钟对准，标定准确的采祥时间。把巡检路线和测点 参数等组态信息输入采集系统。
ch04 收入效应与替代效应
转动和移动
X2 最初预算线 A D X’2 初始选择 最终选择 最终预算线 移动 转动后的预算线 转动 X’1 B E C X1
纯替代效应
纯替代效应是由相对价格变化而引起的 消费需求的变化 讨论纯替代效应的时候要控制实际收入 变化的影响， 变化的影响，即先将这个消费者的收入 调整， 调整，调整后的收入刚好能够按照新的 价格购买原来的消费组合。 价格购买原来的消费组合。
（用绝对量表示的Slutsky方程） 用绝对量表示的Slutsky方程） Slutsky方程
Slutsky方程的推导 方程的推导
∆p1 = −∆m / x1
将上式代入
∆x1 ∆x1 ∆x1 = + ∆p1 ∆p1 ∆p1
s
s m
n
得出Slutsky方程 ∆x1 = ∆x1 − ∆x1 x 方程 得出 1
中级微观经济学 Intermediate microeconomics
Lecture 4 替代效应与收入效应
替代效应与收入效应
价格效应 Hicks方法 方法 Slutsky方法 方法 几个例子 一般化的Slutsky方程 方程 一般化的
价格效应
一个商品的价格变化对需求带来的影 价格效应（ 响 —— 价格效应（price effect） ） 替代效应（ 替代效应（substitution effect） ） 收入效应（ 收入效应（income effect） ）
替代和收入效 应同方向作用 ，正常商品 替代效应>收入效应 替代效应 收入效应 低档商品 替代效应<收入效应 替代效应 收入效应 吉芬商品
Slutsky方法与正常商品
大多数商品是正常商品， 大多数商品是正常商品，替代效应与收 入效应作用方向一致。 入效应作用方向一致。 正常商品的需求曲线是向下倾斜的 （downward slopping）。 ）。 需求法则： 需求法则：如果一种商品的需求随着收 入的增加而增加， 入的增加而增加，那么这种商品的需求 一定随着价格的上升而下降。 一定随着价格的上升而下降。
Ch04.程序流程和异常处理
循环条件(condition)成立？ True 循环体
False
改变循环控制变量 (iterator)
for语句的后继语句
4.3.2 while循环
• • • • • •
False while(条件表达式) 条件表达式？ { True 循环体 循环体语句序列; } while语句的后继语句 说明1~4 【例4.12】利用while循环求1+2+…+100 ，以及1~100 中所有奇数的和、偶数的和 • 【例4.13】求1+2+……的和，直至和>3000为止 • 【例4.14】用近似公式求自然对数的底数e的值，直到 最后一项的绝对值小于10-6为止
4.2.2 switch语句
• switch语句是一个控制语句，它通过将控 制传递给其体内的一个case语句来处理多 个选择和枚举
控制表达式 取值1 语句块1 取值2 语句块2
…… ……
取值n 语句块n
其他 语句块n+1
• 说明1~9
4.3 循环结构
• C#提供了4种不同的循环机制
– – – – for while do...while foreach
4.5 异常处理
• C#中的异常用于处理系统级和应用程序级的错误状态，例如：零 除异常、下标越界、I/O错误等 • 通过使用try语句来定义代码块，实现尝试可能未成功的操作、处 理失败，以及在事后清理资源等 • try • { • // 可能引发异常的语句 • } • catch (异常类型 异常变量) • { • // 在异常发生时执行的代码 • } • finally • { • // 最终必须执行的代码（即使发生异常），如释放资源等 • }
ch04国际经济学课后答案与习题萨尔瓦多
ch04国际经济学课后答案与习题萨尔瓦多萨尔瓦多：国际经济学课后答案与习题第一章介绍国际经济学1. 概念与定义国际经济学是研究国际贸易、国际金融和国际投资等国际经济关系的学科。
它主要研究不同国家之间的贸易、资金流动和其他经济交往，探讨国际经济活动的原因、影响因素和政策措施。
2. 国际经济学的重要性国际经济学旨在帮助人们更好地理解国际经济交往的现象和规律，为国家、企业和个人提供参考依据。
它能揭示经济全球化的趋势、国际贸易的利益和风险，并提供决策者制定政策的理论支持。
第二章国际贸易1. 比较优势理论比较优势理论由大卫·里卡多提出，它认为国家应专注于生产自己具有比较优势的商品，然后通过国际贸易以获取其他商品。
这个理论说明了国际贸易的潜在益处。
2. 绝对优势与比较优势绝对优势是指某个国家在生产某种商品上的效率高于其他国家，而比较优势则是指某个国家在生产某种商品上的机会成本低于其他国家。
比较优势是基于机会成本而产生的。
第三章国际金融1. 汇率与汇率制度汇率是一种货币兑换为另一种货币的比率。
汇率制度是指国家对其货币与其他货币之间的兑换比率进行管理和调整的体系。
汇率制度根据不同的货币政策和国家经济状况而有所不同，如固定汇率制和浮动汇率制等。
2. 随机汇率与管理型汇率制度随机汇率是由市场力量决定的汇率，在市场上自由浮动。
管理型汇率制度是由政府或央行干预市场来控制或影响汇率的变动。
第四章国际投资1. 直接投资与证券投资直接投资是指投资者通过购买或建立企业、工厂或设施等方式，在境外进行经济活动。
证券投资则是指投资者通过购买股票、债券或其他金融资产来获得收益。
2. 外国企业与政府投资外国企业可以通过直接投资的方式，在其他国家建立子公司或扩大在其它国家的经营规模。
政府投资则是指政府通过直接投资的方式，参与国际投资活动，以增加国家的影响力和经济实力。
结语国际经济学是一门重要的学科，它帮助我们理解国际经济交往的规律，为决策者制定政策提供理论支持。
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ERP系统原理和实施 系统原理和实施
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ERP系统原理和实施 系统原理和实施
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4.2 MRP工作原理 工作原理
逐层计算原则 MRP的输入,处理和输出 的输入, 的输入 MRP中的基本数量概念 中的基本数量概念 MRP的运行方式 的运行方式 MRP的开环和闭环 的开环和闭环
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MRP中的基本数量概念 中的基本数量概念
在MRP运算中,经常用到的基本数量概念 运算中, 运算中 包括描述库存信息的数量概念和描述需求 信息的数量概念. 信息的数量概念. 描述库存信息的数量概念包括现有库存量, 描述库存信息的数量概念包括现有库存量, 计划收到量,已分配量,安全库存量, 计划收到量,已分配量,安全库存量,可 用库存量和预计库存量等. 用库存量和预计库存量等. 描述需求信息的数量概念包括总需求量, 描述需求信息的数量概念包括总需求量, 毛需求量,净需求量, 毛需求量,净需求量,计划产出量和计划 投入量等. 投入量等.
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ERP系统原理和实施 系统原理和实施
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ERP系统原理和实施 系统原理和实施
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MRP的输入,处理和输出 的输入, 的输入
MRP最主要的输入数据是 个,即MPS, 最主要的输入数据是3个 最主要的输入数据是 , BOM和库存状况. 和库存状况. 和库存状况 MRP的处理过程主要包括读取 MRP的处理过程主要包括读取MPS数据, 的处理过程主要包括读取MPS数据 数据, 分解BOM,计算物料毛需求,计算物料净 分解 ,计算物料毛需求, 需求和下达作业计划. 需求和下达作业计划. MRP的输出主要是可以用于管理和控制的 的输出主要是可以用于管理和控制的 各种计划和报告. 各种计划和报告.
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ERP系统原理和实施 系统原理和实施
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ERP系统原理和实施 系统原理和实施
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4.4 MRP的计算过程 的计算过程
MRP的计算过程与 的计算过程与MPS的计算过程非常类似,但 的计算过程非常类似, 的计算过程与 的计算过程非常类似 又有所不同.例如, 计算过程中, 又有所不同.例如,在MRP计算过程中,没有预 计算过程中 测量,订单量和可供销售量等数据,因为MRP的 测量,订单量和可供销售量等数据,因为 的 计算量都是相关需求, 计算量都是相关需求,不是可以销售的最终产品 项目;在计算MRP时需要考虑 时需要考虑BOM的分解和低层 项目;在计算 时需要考虑 的分解和低层 码等影响因素; 只涉及到最终产品项目, 码等影响因素;MPS只涉及到最终产品项目,但 只涉及到最终产品项目 是MRP涉及到组成最终产品项目的所有层次的物 涉及到组成最终产品项目的所有层次的物 的计算量和复杂程度远远大于MPS的计 料,MRP的计算量和复杂程度远远大于 的计算量和复杂程度远远大于 的计 算量和复杂程度. 算量和复杂程度.
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ERP系统原理和实施 系统原理和实施
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4.3 低层码的作用
低层码是指同一种物料项目由于位于同一个BOM 低层码是指同一种物料项目由于位于同一个 的不同阶层中或不同的BOM的不同层次中而有多 的不同阶层中或不同的 的不同层次中而有多 个阶层码时, 个阶层码时,取最低层码作为计算该项物料需求 量的一种方法. 量的一种方法.这种方法的目的是确保时间上最 先需求的物料在计划上最先得到库存量, 先需求的物料在计划上最先得到库存量,避免最 后需求的物料提前下达而在计划上占用有限的库 存量. 存量.低层码的引入是对逐层计算原则的一个补 低层码指定了对同一物料位于不同BOM阶层 充,低层码指定了对同一物料位于不同 阶层 时的处理方式. 时的处理方式. 合理安排作业计划,简化作业管理, 合理安排作业计划,简化作业管理,降低库存量 和减少企业流动资金积压
ERP系统原理和实施 系统原理和实施
清华大学出版社
第4章 物料需求计划 章
教学目标 教学重点 教学过程
2010年5月11日
第1页
ERP系统原理和实施 系统原理和实施
清华大学出版社
教学目标
理解和掌握物料需求计划的概念和特点 理解MRP的基本原理 理解 的基本原理 理解和掌握低层码的特点和作用 理解和掌握MRP的运算过程 理解和掌握 的运算过程
2010年5月11日
第6页
ERP系统原理和实施 系统原理和实施
清华大学出版社
MRP应该回答的问题 应该回答的问题
[A] 生产什么?生产多少?何时生产? 生产什么?生产多少?何时生产? [B] 要用到什么?用到多少?何时用到? 要用到什么?用到多少?何时用到? [C] 已经有了什么?有多少?何时使用? 已经有了什么?有多少?何时使用? [D] 还缺少什么?缺少多少?何时需要? 还缺少什么?缺少多少?何时需要? [E] 何时安排? 何时安排?
2010年5月11日
第2页
ERP系统原理和实施 系统原理和实施
清华大学出版社
教学重点
物料需求计划的概念和特点 MRP的基本原理 的基本原理 低层码的特点和作用 MRP的运算过程 的运算过程
2010年5月11日
第3页
ERP系统原理和实施 系统原理和实施
清华大学出版社
教学过程
案例研究: 案例研究:未来的计划 概述 MRP的工作原理 的工作原理 低层码的作用 MRP的计算过程 的计算过程
2010年5月11日 第12页
ERP系统原理和实施 系统原理和实施
清华大学出版社
MRP的运行方式 的运行方式
再生式MRP表示每次计算时,都会覆盖原 再生式 表示每次计算时, 表示每次计算时 来的MRP数据,生成全新的 数据, 来的 数据 生成全新的MRP.再生式 . MRP是周期性运算 是周期性运算MRP,通常的运算周期 是周期性运算 , 是1周. 周 净改变式MRP表示只会根据指定条件而变 净改变式 表示只会根据指定条件而变 例如MPS变化,BOM变化等,经过局 变化, 变化等, 化,例如 变化 变化等 部运算更新原来MRP的部分数据.净改变 的部分数据. 部运算更新原来 的部分数据 是一种连续性的操作, 式MRP是一种连续性的操作,当指定数据 是一种连续性的操作 改变时就需要立刻运行. 改变时就需要立刻运行.
2010年5月11日 第5页
ERP系统原理和实施 系统原理和实施
清华大学出版社
4.1 概述
MRP是一种物料管理和生产方式,是ERP 是一种物料管理和生产方式, 是一种物料管理和生产方式 系统的重要组件,它建立在MPS的基础上, 的基础上, 系统的重要组件,它建立在 的基础上 根据产品的BOM,工艺路线,批量政策和 根据产品的 ,工艺路线, 提前期等技术和管理特征,生成原材料, 提前期等技术和管理特征,生成原材料, 毛坯和外购件的采购作业计划和零部件生 产加工,装配的生产作业计划, 产加工,装配的生产作业计划,从而达到 有效管理和控制企业物料流动的微观计划. 有效管理和控制企业物料流动的微观计划.
2010年5月11日
第9页
ERP系统原理和实施 系统原理和实施
清华大学出版社
逐层计算原则
逐层计算原则是指MRP在计算物料需求时, 在计算物料需求时, 逐层计算原则是指 在计算物料需求时 应该采用自顶向下按照产品结构层次逐层 计算物料需求量的方式. 计算物料需求量的方式. 逐层计算原则是MRP工作原理的重要组成 逐层计算原则是 工作原理的重要组成 部分,它揭示了MRP计算物料需求量的基 部分,它揭示了 计算物料需求量的基 本过程形式,是理解MRP工作原理的基础. 工作原理的基础. 本过程形式,是理解 工作原理的基础
2010年5月11日
第4页
ERP系统原理和实施 系统原理和实施
清华大学出版社
案例研究: 案例研究:未来的计划
1. Oracle公司为什么收购 公司为什么收购PeopleSoft公司? 公司? 公司为什么收购 公司 2. Oracle公司完成收购 公司完成收购PeopleSoft公司之后,为什 公司之后, 公司完成收购 公司之后 么会对SAP公司造成威胁? 公司造成威胁? 么会对 公司造成威胁 3. Oracle公司的未来发展计划和 公司的未来发展计划和SAP公司的未来发 公司的未来发展计划和 公司的未来发 展计划分别是什么? 展计划分别是什么?你认为哪一个公司的发展计 划更可行? 划更可行? 4. Oracle公司和 公司和SAP公司,哪一个更强大一些?为 公司, 公司和 公司 哪一个更强大一些? 什么? 什么? 5. 目前,要想实现自己的发展计划,Oracle公司和 目前,要想实现自己的发展计划, 公司和 SAP公司最迫切需要做的事情是什么?需要什么 公司最迫切需要做的事情是什么? 公司最迫切需要做的事情是什么 资源?为什么?分组讨论. 资源?为什么?分组讨论.