青岛大学机械控制工程基础考研真题2015—2017年
青岛大学2015年硕士研究生入学考试(机械控制工程基础)试题
青岛大学 2015 年硕士研究生入学考试试题
科目代码：821科目名称：机械控制工程基础（共3页）请考生写明题号，将答案全部写在答题纸上，答在试卷上无效一．分析图示钢板厚度控制系统工作原理并绘制系统功能框图。
（20 分）
二．求图示机械系统的微分方程。
图中M为输入转矩,θ为输出转角，Cm为圆周阻尼,J为转动惯量(20 分)
三．基于方框图简化法则，求图示系统的闭环传递函数。
（15 分）
四．对图示系统，要使系统的最大超调量等于 0.2，峰值时间等于 1s ，试确定增益 K 和 Kh 的数值，并确定此时系统的上升时间 tr 和调整时间 ts 。
（15 分）
五．对图示控制系统，求输入 xi (t )=1(t )，扰动 n (t )=1(t )时，系统的总稳态误差。
（15 分）
六．
（15 分）
（15 分） 七．已知系统开环传递函数
G (s )H (s ) =
20 (s +1)(2s +1)(5s +1)
,应用 Nyquist 判 据判别闭环系统的稳定性。
若不稳定，闭环系统有几个正实部的根? (15 分)
八．设控制系统如下图所示 k=10，试
1）画出系统开环 BODE 图（10 分）；
2）求出系统的相位裕度和幅值裕度（10 分）。
九．已知某单位反馈系统，其G(s)和Gc(s)的对数幅频特性渐近线如下图所示。
1）在图中绘出校正后系统的开环对数幅频特性渐近线；（5 分）
2）写出已校正系统的开环传递函数；（5 分）
3）分析Gc(s)对系统的校正作用。
（5 分）。
青岛大学2015年硕士研究生入学考试初试试题考试科目：872运筹学
三、 （20 分）某公司根据年度生产计划安排，拟将某种高效率的五台设备， 分配给所属的甲乙丙三个工厂， 各子工厂若获得这种设备之后， 可以为总公 司带来的盈利如下表：
子工厂的盈利/ 万元 甲 设备台数 0 1 2 3 4 5
请用动态规划求解上述问题。
1
乙 0 5 10 11 11 11
丙 0 5 8 12 13 14
0 3 7 9 12 13
四、（20分）某公司下属有甲、乙、丙三个工厂，分别向A、B、C、D四个销 售地提供产品，产量、需求量及工厂到销售地的运价（单位：元/每吨）如 下表所示： 销地 工厂 甲 乙 丙 销量（吨） 16 A 8 9 14 15 B 6 12 12 7 C 10 13 16 17 D 9 7 5 产量（吨） 18 18 19 55
试求：（1）费用最小的最佳运输方案； （2） 若原问题中所有的运价都提高10元/吨， 最佳运输方案是否保持 不变了？ （3）若在最小费用不变的条件下，要求丙工厂运往B、C两地的数量 一样，可否调整？若可调整，写出调整后的解。 五、 （15 分）假设 A、B、C、D、E 五名游泳运动员的各项泳姿的 100 米游泳 成绩如表所示： （秒） 仰泳 A B C D E 80.4 69.8 72.6 79.0 75.8 蛙泳 91.8 71.2 89.4 74.4 88.6 蝶泳 71.6 62.0 82.8 65.8 72.2 自由泳 63.4 57.8 64.2 62.0 67.2
2
开工；
工序代号 工序名称
清理场地，准备开工 备料 车库地面施工 预制墙及房顶的架 车库混凝土地面养护 立墙架 立房顶架 装窗及边墙 装门 装天花板 油漆 引道混凝土施工 引道混凝土保养 清理、交工
【青岛大学2012年考研专业课真题】机械控制工程基础2012
ma x ，并计算当相位裕量为最大值 max 时，系统的开环截止频率 c 和增益
Kc 。 （20 分)
2
R( s )
K c (1 Βιβλιοθήκη 1 ) sKs 1 Ta s
1 Ti s
C ( s)
七．设系统的开环传递函数为 GK ( s)
K (T2 s 1) (其中K 0, T1 0, T2 0) s 2 (T1 s 1)
试画出 Nyquist 图， 并确定系统的稳定性。 （要求： 按 T1 T2 ，T1 T2 ，
T1 T2 三种情况分别讨论） 。 （30 分）
八．一单位反馈系统的开环传递函数为
G( s)
K s(1 0.2s)(1 0.05s)
求： （1） K 1 时系统的相位裕度和幅值增益裕度。 （10 分） （2）要求通过增益 K 的调整，使系统的增益裕度为 20dB，相位裕度 满足 40 。 （10 分）
青岛大学 2012 年硕士研究生入学考试试题
科目代码： 821 科目名称： 机械工程控制基础 （共 3 页） 请考生写明题号，将答案全部写在答题纸上，答在试卷上无效 注：仅限使用只具有计算功能的计算器 一．仓库大门自动控制系统如图所示，试分析系统的工作原理，绘制系统 的方框图。 （10 分）
放大器
伺服电动机
1
四. 如图所示的单位反馈随动系统， K 16s 1 ,T 0.25s ，试求：
（1）求特征参数 ， n ； （5 分） （2）计算最大超调量和调整时间； （ 2% ） （5 分） （3）若要求最大超调量为 16%，当 T 不变时 K 应当取何值？（10 分）
五.系统的结构图如图所示，试求
青岛大学概率论及数理统计一考研真题2015—2017年
0 x y 1; 其它.
求 (X ,Y) 分别关于 X 和Y 的边缘概率密度 fx x, fy y 。
5：(15 分) 已知随机变量 X N 0, 2 ，Y 在区间 0, 3 上服从均匀分
布，且 D X Y 2 ，求 X 和Y 的相关系数 。
3
2
2）若该机床已停机，求它是在加工零件 A 时发生停机的概率。 七、（15 分）设事件 A, B 及 A B 的概率分别为 p 、q 及 r ，求 P( AB) ，P( AB) ， P( AB) ， P( AB) 。
3
青岛大学 2016 年硕士研究生入学考试试题
科目代码： 619 科目名称：概率论及数理统计 （共 3 页） 请考生写明题号，将答案答在答题纸上，答在试卷上无效
2. 随机变量 X 与 Y 相互独立，且方差为 D X 4 ， D Y 2 ，则方差
D 3X 2Y ＝________.
3. 一个袋子中有相同大小的红球 6 只、黑球 4 只，从中不放回地抽取 2
只，则第一次和第二次都取到红色球的概率为
。
4. 设 E(X ) 2 , E(Y ) 3 , 则 E(X Y 5)
EX ______。
，则
2、(4 分) 设 A、B、C 是三个随机事件，则“事件 A、B、C 不多于一个发
生”的逆事件是________。
3、（4 分）设 P(A) 0.5, P(B) 0.6, P(A B) 0.9 ,则 P(B | A) __________.
4、（4
分）随机变量 X
的概率密度函数
4x2 4K x K 2 有0 根的判别式所决定有实根的概率。 3：(15 分) 设随机变量 X 具有密度函数 f (x) 1 e|x| ， x ，求 X
青岛大学管理学考研真题2015—2017年
青岛大学2015年硕士研究生入学考试试题科目代码：859 科目名称：管理学（2）（共2 页）请考生写明题号，将答案全部答在答题纸上，答在试卷上无效一、填充题（每空1分，共22分）1.根据罗伯特·卡茨的研究，管理者要具备三类技能：_________ , ________和________。
2.马斯洛的高层需要即赫茨伯格双因素理论的主要_______因素，而为了维持生活所必须满足的低层需要则相当于_____因素。
3.管理和战略，__________告诉我们怎样“做正确的事”，_________在解决如何“正确地做事”。
4.新经济时代，经营目标的创新体现在以_____________代替利润最大化，以____________代替市场份额。
5.从环境因素的可控程度看，可把决策分为_________、_________和_________。
6.常规计划包括_________、_________和_________，所有这些都是准备用来处理常发性问题的。
7.按企业对竞争的方式和态度分，其经营战略可以分为_____________、___________及___________。
8.尊重的需要可以分为两类，即_______________和_____________。
9.从创新的规模以及创新对系统的影响程度来考察，可将其分为_________和_________。
二、辨析题（每题15分，共30分）1.从2010年1月23日的“马向前事件”到2010年5月27日的第十三连跳，富士康跳楼事件说明泰勒的科学管理理论逐渐丧失了科学性和适用性，应该适当扬弃。
2.企业经营目标是盈利，承担社会责任会占用原本可以用来盈利的资源，会进一步给企业造成经济损失，所以企业不应该承担社会责任。
三、简答题（从10个题中选择8个题，每题6分，共48分）1.简要回答弗雷德里克·赫茨伯格双因素理论的基本观点。
2.简要回答人本原理的主要观点。
2017年青岛大学考研试题821机械控制工程基础
2
青岛大学 2017 年硕士研究生入学考试试题
科目代码： 821 科目名称： 机械控制工程基础 （共 2 页） 请考生写明题号，将答案全部答在答题纸上，答在试卷上无效 一．下图所示为一液面控制系统。图中 Ka 为放大器的增益，D 为执行电动机，N 为减速器。试分析该系统的工作原理，画出系统控制方框图，并在系统中找出控 制量、扰动量、被控制量、控制器和被控对象。 （20 分）
五．对于具有 25s 5 105s 4 120s 3 122s 2 20s 1 0 特征方程的反馈系统，试应用 劳斯判据确定在 s 的右半平面特征方程是否有根？（15 分） 六．已知某开环稳定的闭环系统，当开环增益 K=500 时，其开环频率特性的 Nyquist 图如下，试确定系统稳定时，开环增益 K图所示，试求系统传递函数。 （20 分）
八．已知某单位反馈系统的开环传递函数为：G ( s )
K ，若要求系统单位 s (0.5s 1)
速度信号输入时稳态误差为 0.05，相角裕度不小于 450，幅值裕度不小于 10dB, 试确定超前校正装置的传递函数。(30 分)
二．设无源网络如下图所示，试求其传递函数 U2(s)/U1(s)。 （15 分）
三．基于方框图简化法则，求图示系统的闭环传递函数。 （15 分）
1
四、设控制系统的方框图如图所示，系统输入端除有用信号 r(t)以外，还夹杂 有扰动 n(t)。已知： r(t)=10t,n(t)=0.1sin10t。试计算系统稳态误差的最大值。 （20 分）
青岛大学化工原理考研真题2015、2017年
青岛大学2015年硕士研究生入学考试试题科目代码：834科目名称：化工原理（共2页）请考生写明题号，将答案全部答在答题纸上，答在试卷上无效一、简答题（共60分，每题12分）１.理想伯努利方程能量式和成立条件。
２.旋风分离器的临界粒径概念及影响因素。
３.牛顿冷却定律和影响因素。
４.气膜控制现象和强化传质的措施。
５.干燥过程的结合水分和非结合水分概念二、计算题（30分）如图所示，用离心泵将水从敞口的水池输送到敞口的高位储槽内，吸入管为∅85⨯2.5mm的钢管，管长L1=6m，摩擦系数可取λ1=0.02，压出管为∅65⨯2.5mm的钢管，管长L2=13m，摩擦系数λ2可取为0.03，吸入和压出各有900的弯头，其阻力系数为0.75，压出管路上的阀门阻力系数为6.4，水池及储槽内的液面高度保持不变。
H=10m，泵进口高于水池面2m，管内流量为0.012m3/s，试求：每kg水需从离心泵获得多少机械能？三、计算题（30分）在一传热面积为20m2的某换热器中，用温度为200C、流量为13200kg/h的冷却水，冷却进口温度1100C的醋酸。
两流体逆流流动。
换热器刚投入使用时，冷却水出口温度为450C，而醇酸出口温度为400C。
运转一段时间后，两流体的流量、进口温度均不变，而冷却水的出口温度变化为380C，试求醋酸出口温度为若干？（水的比热分别是4.2kJ/（kg K），换热器的热损失可忽略不计）四、计算题（30分）在一连续精馏塔中分离某混合液，xD =0.94，xW=0.04，已知此塔进料q线方程y=6x－1.5，采用回流比为最小回流比的1.2倍。
混合液在本题条件下相对挥发度为2，求：（1）精馏段操作线方程；（2）若塔底产品W=150kmol/h，求进料量F和塔顶产品量D；（3）提馏段操作线方程。
青岛大学计控-2015年春季计算机控制技术(A卷)参考答案
x7=x6-1=2,y7=4
8
F7<0
+y
F8=F7+2y7+1=4
x8=2,y8=y7+1=5
9
F8>0
-x
F9=F8-2x8+1=1
X9=x8-1=1,y9=5
10
F9>0
-x
F10=F9-2x9+1=0
X10=x9-1=0,y10=5
（2）根据上表，可作出走步轨迹如图所示。（4 分）
Nxy=10 Nxy=9 Nxy=8 Nxy=7 Nxy=6 Nxy=5 Nxy=4 Nxy=3 Nxy=2 Nxy=1 Nxy=0
Z
1
e s
Ts
GC (s)
，求广义对象的脉冲传递函数 G(z)
。
3）根据
D(
z)
1 G(z)
1
Φ(z) Φ(z)
求取数字控制器的脉冲传递函数
D(
z)
。
m
4）根据 D(z)
U (z) E(z)
bi z i
i0 n
1 ai z i
,
i 1
m
n
(n m) 求取控制量 u(k) 的递推计算公式 u(k) bie(k i) aiu(k i) 。
（3）分别画出 u(k)和系统输出 y(k)的波形。 [16 分]
解：（1）首先求取广义对象的脉冲传递函数
G(z)
Z
1
e s
Ts
1 s2
ቤተ መጻሕፍቲ ባይዱ
(1
z
1
)Z
1 s3
z 1(1 z 1 ) 2(1 z 1 )2
由 G(z)的表达式和 Gc(s)知，满足无纹波设计的必要条件，且 d=0,q=2,v=2,w=1,j=2,且 j≤q，故有
青岛大学计控-第3章 数字控制技术
T9、第二象限逆圆弧插补，当偏差 Fm 0 时，下一步的进给方向为 。
A、+x
B、-x
C、+y
D、-y
答案：B
知识点：逐点比较法圆弧插补
参考页：P80
学习目标：2（掌握插补原理）
难度系数：1
题型：选择
T10、第四象限逆圆弧插补，当偏差 Fm 0 时，下一步的进给方向为 。
A、+x
B、-x
C、+y
序控制
知识点：数字控制基础
参考页：P69
学习目标：1（熟悉数字控制的原理、方式和系统结构）
难度系数：1
题型：填空
T 4 、 顺序控制是以
为依据，按预先
完成工作的自动控制。
答案：预先规定好的时间或条件；规定好的动作次序顺序地
知识点：数字控制基础
参考页：P69
学习目标：1（熟悉数字控制的原理、方式和系统结构）
第三章 数字控制技术（共 65 题）
附注：教学目标 通过本章的学习，学生应达到如下基本要求： 1、熟悉数字控制的原理、方式和系统结构 2、掌握插补原理 3、掌握多轴步进驱动控制技术 4、掌握多轴伺服驱动控制技术
一、填空题（共 27 题）
T1、所谓数字控制，就是生产机械(如各种加工机床)根据 ，按规定的 、 、 、 等规律自动地完成工作的控制方式。 答案：数字计算机输出的数字信号，工作顺序，运动轨迹，运动距离，运动速度 知识点：数字控制基础 参考页：P69 学习目标：1（熟悉数字控制的原理、方式和系统结构） 难度系数：1 题型：填空
。 C、偏差计算
D、坐标计算
T6、第三象限直线插补，当偏差 Fm 0 时，下一步的进给方向为 。
A、+x
青岛大学2015年硕士研究生入学考试初试试题考试科目：642基础英语
青岛大学2015年硕士研究生入学考试试题科目代码： 642 科目名称：基础英语(共12页）请考生写明题号，将答案全部答在答题纸上，答在试卷上无效PART I SENTENCE COMPLETION (30 points )Choose the word or the set of words that, when inserted in the sentence, best fits the meaning of the sentence as a whole.1. Like a credit card in appearance, the smart card contains a microchip that stores digital tokens which can be exchanged for goods, just like ______ cash.A. concreteB. tentativeC. tangibleD. intact2. The Team of England, who are now superbly fit, will be doing their best next week to______ themselves for last year’s defeat.A. reviveB. retortC. revenge D remedy3. When Tastuma first came to the US from Japan, he wasn’t sure he could ______ intothe American culture, but after a few months , he felt at home here.A. absorbB. transformC. digest D assimilate4. The constitution of the State required that property should be _____ for taxation at itsmarket value.A. estimatedB. appraisedC. evaluatedD. valued5. The idealized paintings of nature produced in the 18th century are evidence thatmedieval ______ natural settings had been ______and that the outdoors now could be enjoyed without trepidation.A. fear of …exorcisedB. concerns about …regainedC. affection for …surmountedD. disinterest in …alleviated6. Edith Wharton sought in her memoir to present herself as having achieved a harmonious wholeness by having ________ the conflicting elements of her life.A.affirmedB. highlightedC. reconciledD. confined7. In the 20th century, the discovery of radium _____ the popular imagination; not only was its discoverer, Marie Curie, idolized, but its market value ______ that of the rarest gemstone.A. stormed … diminishedB. horrified …approachedC. enflamed… exceededD. conspired… triggered8. Since the 15th century, animals have been used as ____ for people in experiments to assess the effects of therapeutic and other agents that might later be used in humans.A. benefactorsB. companionsC. surrogatesD. precedents9. Issues of price, place, promotion, and product are _______ conventional concerns in planning marketing strategies.A. these of the mostB. most of thoseC. among the mostD. among the many of10. The disagreement over the trade restrictions could seriously _______ relations between the two countries.A. tumbleB. jeopardizeC. manipulateD. intimidate11. New research raises new concerns that altering crops to withstand such treats maypose new risks---from _____the weeds themselves.A. anything butB. other thanC. more thanD. none other than12. In this small village, he found few persons ___ to him and felt quite lonely.A. congenitalB. contentiousC. congenialD. Concurrent13. The chief reason for the population growth isn’t so much a rise in birth rates ____ afall in death rates as a result of improvements in medical care.A. andB. as C but D or14. Bipartisan bills are pending in Congress that would eliminate all travel restrictionsand ______ the embargo.A. freeB. slackenC. unwindD. ease15. Rather than enhancing a country's security, the successful development of nuclearweapons could serve at first to increase that country's ________.A.boldnessB.influenceC. responsibilityD. vulnerability16. Although scientists claim that the seemingly ________ language of their reports ismore precise than the figurative language of fiction, the language of science, like all language, is inherently ________.A.ornamental ... subtleB. unidimensional ... unintelligibleC. symbolic ... complexD. literal ... allusive17. Laws do not ensure social order since laws can always be ________, which makesthem ________ unless the authorities have the will and the power to detect andpunish wrongdoing.A.contested ... provisionalB. circumvented ... antiquatedB.repealed ... vulnerable D. violated ... ineffective18. The pressure of population on available resources is the key to understanding history;consequently, any historical writing that takes no cognizance of______ factsis______ flawed.A.demographic….intrinsicallyB.ecological…. marginallyC. cultural…..substantivelyD. psychological…philosophically19. By putting billions of dollars into the ailing automaker, the Obama administrationhas placed a huge bet on the effort to revive and _____ the company through the elimination of brands, dealerships and factories.A. streamlineB. strayC. strikeD. strife20. Under the deal, the union’s cost-of-living interests, performance bonuses and someholiday pay will be _____ to offset health-care costs.A. sustainB. retakeC. swabD. suspend21. The capital intended to broaden the export base and ____efficiency gains frominternational trade was channeled instead into uneconomic import substitution.A. secureB. extendC. defendD. possess22. New sources of energy must be found, and this will take time, but it is not likely toresult in any situation that will ever restore that sense of cheap and _____ energy we have had in the times past.A. exquisiteB. resilientC. copiousD. formidable23. Gaddis is a formidably talented writer whose work has been, unhappily, more likelyto intimidate or his readers than to lure them into his fictional world.A. enticeB. strengthenC. transformD. repel24. Her is always a source of irritation: she never uses a single word when shecan substitute a long clause or phrase in its place.A. verbosityB. simplicityC. cogencyD. rhetoric25. If those large publishers that respond solely to popular literary trends continue todominate the publishing market, the initial publication of new writers will depend on the writer’s willingness to________ popular tastes.A. struggle againstB. cater toC. admireD. flout26. Contrary to the popular conception that it is powered by conscious objectivity,science often operates through error, happy accidents, ________ and persistence in spite of mistakes.A. controlsB. hunchesC. deductionsD. calculations27. By putting the entire Woolf archive on a microfilm, the project directors hope tomake the contents of manuscripts more _____ to scholars.A.objectiveB. accessibleC. appealingD. implicit28. Despite the ________ of many of their colleagues, some scholars have begun toemphasize "pop culture" as a key for ________ the myths, hopes, and fears ofcontemporary society.A.antipathy ... entanglingB. discernment ... evaluatingC. skepticism ... decipheringD. pedantry ... reinstating29. The powers and satisfactions of primeval people, though few and meager,were______ their few and simple desires.A.simultaneous withB. commensurate withC. substantiated byD. ruined by30. Social scientists have established fairly clear-cut ________ that describe theappropriate behavior of children and adults, but there seems to be ________ about what constitutes appropriate behavior for adolescents.A.functions ... rigidityB. estimates ... indirectnessC. norms ... confusionD. regulations ... certaintyPART II PROOF READING AND ERROR CORRECTION (10 Points) The following passage contains TEN errors. Each line contains a maximum of ONE error. In each case, only ONE word is involved. You should proofread the passage and correct it in the following way.For a wrong word, underline the wrong word and write the correct one in the blank provided at the end of the line.For a missing word, mark the position of the missing word with a “∧”sign and write the word you believe to be missing in the blank provided at the end of the line.For an unnecessary word cross out the unnecessary word with a slash “/”and put the word in the blank provided at the end of the line.In many states, budget requests by state universities have had tobe scaled back or frozen, while tuition, the share of the cost borne bythe students themselves, has gone up. The problem with the governors (1) __________is particularly distressing because they all agree that the quality oftheir colleges and universities helps drive the economic enginesof their states. And they are constantly being told by everyone like (2) ___________college administrators to editorial writers that only way to make (3)___________their state universities better is to spend more money.But it was against this backdrop that members of the Association(4)___________came together in this city to discuss issues of common concern, oneis higher education. And the focus of their talks about colleges(5)____________centered not on how money could be more effectively directed,but on what to get greater productivity out of a system that has(6)____________become highly inefficient and resistive against change.(7)_____________As a result, the governors will embark a three-year study of (8) _____________higher education system and how to make state colleges anduniversities better able to meet the challenges of a global economy inthe 21st century. And judging from the tenor and tone of theirdiscussion, the study could produce a push in for higher standards, (9) ___________more efficiency and greater accountability. Pennsylvania GovernorTom Ridge and his fellow governors came away from the meetingsresolute with the belief that higher education needs a fresh look and (10) ____________possibly a major boost in productivity to meet demands of newtechnologies and a changing work force.PART III READING COMPREHENSION (30 Points)In this section there are three reading passages followed by a total of fifteen multiple-choice questions. Read the passages and then write your answers on your answer sheet.Passage1Despite Denmark’s manifest virtues, Danes never talk about how proud they are to be Danes. This would sound weird in Danish. When Danes talk to foreigners about Denmark, they always begin by commenting on its tininess, its unimportance , the difficulty of its language, the general small-mindedness and self-indulgence of their countrymen and the high taxes. No Dane would look you in the eye and say, “Denmark is a great country.” You’re supposed to figure this out for yourself.It is the land of the silk safety net, where almost half the national budget goes toward smoothing out life’s inequalities, and there is plenty of money for schools, day care, retraining programmes, job seminars-- Danes love seminars: three days at a study centre hearing about waste management is almost as good as a ski trip. It is a culture bombarded by English, in advertising, pop music, the Internet, and despite all the English that Danish absorbs—there is no Danish Academy to defend against it —old dialects persist in Jutland that can barely be understood by Copenhageners. It is the land where, as the saying goes, “Few have too much and fewer have too little, ”and a foreigner is struck by the sweet egalitarianism that prevails, where the lowliest clerkgives you a level gaze, where Sir and Madame have disappeared from common usage, even Mr. and Mrs. It’ s a nation of recyclers—about 55 % of Danish garbage gets made into something new—and no nuclear power plants. It’s a nation of tireless planner.Trains run on time. Things operate well in general.Such a nation of overachievers —a brochure from the Ministry of Business and Industry says, “Denmark is one of the world’s cleanest and most organize d countries, with virtually no pollution, crime, or poverty. Denmark is the most corruption-free society in the Northern Hemisphere.”So, of course, one’s heart lifts at any sighting of Danish sleaze: skinhead graffiti on buildings (“Foreigners Out of Denmark! ”), brokenNonetheless, it is an orderly land. You drive through a Danish town, it comes to an end at a stone wall, and on the other side is a field of barley, a nice clean line: town here, country there. It is not a nation of jay-walkers. People stand on the curb and wait for the red light t o change, even if it’s 2 a.m. and there’s not a car in sight. However, Danes don’ t think of themselves as a wait- ing-at-2-a.m.-for-the-green-light people——th at’s how they see Swedes and Germans. Danes see themselves as jazzy people, improvisers, more free spirited than Swedes, but the truth is (though one should not say it)that Danes are very much like Germans and Swedes. Orderliness is a main selling point. Denmark has few natural resources, limited manufacturing capability; its future in Europe will be as a broker, banker, and distributor of goods. You send your goods by container ship to Copenhagen, and these bright, young, English-speaking, utterly honest, highly disciplined people will get your goods around to Scandinavia, the Baltic States, and Russia. Airports, seaports, highways, and rail lines are ultramodern and well-The orderliness of the society doesn’t mea n that Danish lives are less messy or lonely than yours or mine, and no Dane would tell you so. You can hear plenty about bitter family feuds and the sorrows of alcoholism and about perfectly sensible people who went off one day and killed themselves. An orderly society can not exempt itsBut there is a sense of entitlement and security that Danes grow up with. Certain things are yours by virtue of citizenshi p, and you shouldn’t feel bad fo r taking what you’re entitled to, you’re as good as anyone else. The rules of the welfare system are clear to everyone, the benefits you get if you lose your job, the steps you take to get a new one; and the orderliness of the system makes it possible for the country to weather high unemployment and social unrest without a sense of crisis.1. The author thinks that Danes adopt a ___ attitude towards their country.A. boastfulB. modestC. deprecating2. Which of the following is NOT a Danish characteristic cited in the paA. Fondness of foreign culture.C. Linguistic tolerance.D. Persistent planning.3. The author’s reaction to the statemen t by the Ministry of Business and Industry is ___.A. disapprovingB. approving D. doubtful4D. prevents Danes from acknowledg5. At the end of the passage the author states all the following EXCEPT thatC. the open system helps to tide the couPassage 2Education is an important theme in youth athletics in the US. Young kids, energetic, noisy, uncontrollable, confined to class, yearn for the relative freedom of the football field, the basketball court, the baseball diamond. They long to kick and throw things and tackle each other, and the fields of organized play offer a place in which to act out these impulses. Kids are basically encouraged, after all, to beat each other up in the football field. Yet for all the chaos, adult guidance and supervision are never far off, and time spent on the athletic fields is meant to be productive. Conscientious coaches seek to impart lessons in teamwork, self-sacrifice, competition, gracious winning and losing. Teachers at least want their pupils worn out so they’ll sit still in reading class.By the time children start competing for spots on junior high soccer teams or tennis squads, the kids’ gloves have come off to some extent. The athletic fields become less a place to learn about soft values like teamwork than about hard self-discipline and competition. Competitiveness, after all, is prized highly by Americans, perhaps more so than by other peoples. For a child, being cut from the hockey team or denied a spot on the swimming is a grave disappointment—— and perhaps an opportunity for emotional or spiritual growth.High school basketball or football teams are places where the ethos of competition is given still stronger emphasis. Although high school coaches still consider themselves educators, the sports they oversee are not simple extensions of the classroom. They are important social institutions, for football games bring people together. In much of the US they are events where young people and their elders mingle and see how the community is evolving.For the best players, the progression from little league to junior high to high schoolleads to a scholarship at a famous college and maybe, one day, a shot at the pros. To all appearances, college athletes are student-athletes, an ideal that suggests a balance between the intellectual rigors of the university and the physical rigors of the playing field. The reality is skewed heavily in favor of athletics. One would have difficulty showing that major US college sports are about education. Coaches require far too much of players’ time to be truly concerned with any thing other than performance in sport. Too often, the players they recruit seem to care little about school themselves.This was not always the case. Universities — Princeton, Harvard, Rutgers, Yale —were the birthplaces of American football and baseball; education—the formation of “character” —was an important part of what those coaches and players thought they were achieving. In 1913, when football was almost outlawed in the US, the game’s most prominent figures traveled to Washington and argued successfully that football was an essential part of the campus experience and that the nation would be robbed of its boldest young men, its best potential leaders, if the game were banned.The idea that competitive sports build character, a western tradition dating from ancient Greece, has evidently fallen out of fashion in today’s US. Educators, now prone to see the kind of character shaped by football and basketball in dark light, have challenged the notion that college sports produce interesting people. Prominent athletes, such as boxer Muhammad Ali and basketball star Charles Markley, deliberately distanced themselves from the earlier ideal of the athlete as a model figure. Today’s US athlete is thus content to be an entertainer.Trying to do something socially constructive, like being a role model, will make you seem over-earnest and probably hurt your street credibility.When I was a kid, my heroes played on Saturdays: they were high school players and college athletes. Pro football games, broadcast on Sunday afternoons, were dull and uninspiring by comparison. After all, why would God schedule anything important for Sun day? You’ve got school the next day.Although I certainly couldn’t have articulated it at the time, I think I must already have sensed that throwing a ball or catching passes was a fairly pointless thing to be good at. In the grand scheme, it was a silly preparation for a job. Yet playing sports was not pointless; the point, however, was that you were learning something——a disposition, a certain virtue, a capacity of arduous endeavor——that might be of value when you later embarked upon a productive career as a doctor or a schoolteacher or a businessman. The optimism of those Saturday afternoons was infectious. I still feel that way today.6. Pupils mainly learn ______ on the athletic fields.A. soft valuesB. hard valuesC. value for freedomD. value of equality7. In high school basketball or football teamsA. hard values are less emphasizedB. the sports are separated fromclassrooms.C. the social function of sports is prominent.D. the coaches are less of educators.8. Which of the following is NOT true about college sports?A. The best players may end up getting a scholarship at a famous college.B. College athletes have always cared little about school themselves.C. College sports are more in favor of athletics than education.D. The formation of “character” used to be the goal of coaches and players.9. The author’s attitude toward the notion of “athletes as entertainers” isA. positiveB. neutralC. negativeD. impossible to tell.10. The best title for this passage isA. Education System in the USB. Development of Athletics in the USC. US Education in Youth AthleticsD. Development of Education in the US.Passage 3Human migration: the term is vague. What people usually think of is the permanent movement of people from one home to another. More broadly, though, migration means all the ways—from the seasonal drift of agricultural workers within a country to the relocation of refugees from one country to another.Migration is big, dangerous, compelling. It is 60 million Europeans leaving home from the 16th to the 20th centuries. It is some 15 million Hindus, Sikhs, and Muslims swept up in a tumultuous shuffle of the citizens between India and Pakistan after the partition of the subcontinent in 1947.Migration is the dynamic undertow of population change: everyon e’s solution, everyon e’s conflict. As the century turns, migration, with its inevitable economic and political turmoil, has been called “one of the greatest challenges of the coming century.”But it is much more than that. It is , as it has always been, the great adventure of human life. Migration helped create humans, drove us to conquer the planet, shaped our societies, and promised to reshape them again.“You have a history book written in your genes,” said Spencer Wells. The book he is trying to read goes back to long before the first word was written, and it is a story of migration.Wells, a tall, blond geneticist at Stanford University, spent the summer of 1998 exploring remote parts of Transcaucasia and Central Asia with three colleagues in a Land Rover, looking for drops of blood. In the blood, donated by the people he met, he will search for the story that genetic markers can tell of the long paths human life has taken across the Earth.Genetic studies are the latest technique in a long effort of modern humans to find out where they have come from. But however the paths are traced, the basic story issimple: people have been moving since they were people. If early humans hadn't moved and intermingled as much as they did, they probably would have continued to evolve into different species. From beginnings in Africa, most researchers agree, groups of hunter-gatherers spread out, driven to the ends of the Earth.To demographer Kingsley Davis, two things made migration happen. First, human beings, with their tools and language, could adapt to different conditions without having to wait for evolution to make them suitable for a new niche. Second, as populations grew, cultures began to differ, and inequalities developed between groups. The first factor gave us the keys to the door of any room on the planets; the other gave us reasons to use them.Over the centuries, as agriculture spread across the planet, people moved toward places where metal was found and worked and to centres of commerce that then became cities. Those places were, in turn, invaded and overrun by people later generations called barbarians.In between these storm surges were steadier but similarly profound tides in which people moved out to colonize or were captured and brought in as slaves. For a while the population of Athens, that city of legendary enlightenment was as much as 35 percent slaves."What strikes me is how important migration is as a cause and effect in the great world events." Mark Miller, co-author of The Age of Migration and a professor of political science at the University of Delaware, told me recently.It is difficult to think of any great events that did not involve migration. Religions spawned pilgrims or settlers; wars drove refugees before them and made new land available for the conquerors; political upheavals displaced thousands or millions; economic innovations drew workers and entrepreneurs like magnets; environmental disasters like famine or disease pushed their bedraggled survivors anywhere they could replant hope."Its part of our nature, this movement," Miller said, "It's just a fact of the human condition."11. Which of the following statements is INCORRECT?A. Migration exerts a great impact on population change.B. Migration contributes to Mankind’s progress.C. Migration brings about desirable and undesirable effects.D. Migration may not be accompanied by human conflicts.12. What do we know about Spencer Wells from the passage?A. He thought genes can tell where people have come from.B. He wrote a book about the history of genes.C. He read the first history book at Stanford UniversityD. He agreed human migration was from Transcaucasia and central Asia.13. According to Kingsley Davis, migration occurs as a result of the following reasonsEXCEPT ______.A. human adaptabilityB. human evolutionC. cultural differencesD. inter-group inequalities14. Which of the following groups is NOT mentioned as migrants in the passage?A. Farmers.B. Workers.C. Settlers.D. Colonizers.15. There seems to be a(n) ______ relationship between great events and migration.A. looseB. indefiniteC. causalD. remotePART IV TRANSLATION FROM ENGLISH INTO CHINESE (40 Points)What happens to the students who cheat on the two college admissions exam, the SAT and the ACT? Not as much as you might think. It isn’t particularly easy to cheat on these exams, but that doesn’t stop some students from trying. They do it in all the ways you might imagi ne: Copying off someone else’s paper, texting on a cellphone for answers, bringing in cheat sheets, having someone else take the test for them.And some cheat in ways you might not consider: In South Korea, a test prep tutor was investigated for allegedly buying scanned copies of sections of the SAT and then emailing them, with the answers, to South Koreans in Connecticut who were going to take the test 12 hours later. Another SAT tutor in South Korea was arrested for getting students taking the SAT to put test questions into a calculator they were allowed to use, and to hide small blades in their erasers that they used to cut out pages of the test. So, you ask, what happens to students suspected of cheating on the SAT or the ACT?I asked both the College Board, which owns the SA T, and ACT Inc., which owns the ACT, to explain what triggers suspicion of cheating and what happens to students found to be cheating. Ed Co lby, spokesman for the ACT, said he couldn’t tell me exactly how many investigations are conducted each year for security reasons. Tom Ewing, a spokesman for the Educational Testing Service, which administers the SAT for the College Board, said there are a few thousand questionable test scores each year out of more than 2 million tests. Both said a review of a student’s test could be triggered in one of several ways, including an audit that flags scores that have risen dramatically, or by a tip from outside parties, such as a guidance counselor, college admissions officer or NCAA official.PART V WRITING (40 Points)In most countries, with the widespread of the use of Internet, people have more freedom to choose to work and study at home instead of travelling to work or college. Do the advantages outweigh the disadvantages?Write an essay of about 400words, Use specific reasons/examples to support your position on the statement above. In the first part of your writing you should present your thesis statement, and in the second part you should support the thesis statement with appropriate details. In the last part you should bring what you have written to a natural conclusion or make a summary.You should supply an appropriate title for your essay.Marks will be awarded for content, organization, grammar, diction and appropriateness. Failure to follow the above instructions may result in a loss of marks.。
青岛大学2015年硕士研究生入学考试(概率论及数理统计(2))试题
青岛大学 2015 年硕士研究生入学考试试题科目代码：852 科目名称：概率论及数理统计（2）（共 3 页）请考生写明题号，将答案全部答在答题纸上，答在试卷上无效一、解释概念（30 分，每题 6 分）（1）古典概型与几何概型（2）条件分布与条件期望（3）依概率收敛与分布收敛（4）估计统计量与检验统计量（5）相关分析与回归分析二、计算题（20 分）某工厂有四条流水线生产同一种产品，该四条流水线的产量分别占总产量的 15%，20%，30%，35%，又这四条流水线的次品率依次为 5%，4%，3%，2%，问：（1）现从出厂产品中任取一件，问恰好取到次品的概率为多少？（2）在出厂产品中随机地取一件产品发现是次品，为进行产品质量追溯，此次品出自第 1 条流水线生产的概率是多少？三、计算题（20 分）设有 A，B 两种不相关的证券，它们的收益与概率如下表：问：（1）应如何投资这两种证券最佳？（2）若这两种证券相关，相关系数ρA,B =-0.5，结果又如何？四、证明题（20 分）若对连续型随机变量ξ，有 E ξrE ξrp(ξ>ε)≤εr并由此验证切比雪夫不等式成立！< +∞ (r>0)，证明：五、计算题（20 分）设随机变量ξ的密度函数为：⎧ax,0 <x< 2p(x)=⎪cx + b, 2≤ x <4⎨⎪x ≤0 or x ≥40,⎩且已知 E(ξ)=2,p{1<ξ<3}=43，试求：（1）a，b，c的值；（2）随机变量η=eξ的数学期望与方差。
六、计算题（20 分）2η服从对数正态分布，（1）设随机变量η服从分布N (μ,σ) ，则ξ=e求此对数正态分布密度；（2）设（ξ1,ξ2,...,ξn)是取自上述对数正态分布的母体ξ的一个子样，分别求μ,σ2的极大似然估计。
七、计算题（20 分）某居民小区进行了两次城镇职工收入调查，抽样记录可支配收入情况如下（千元）：第一次：第二次：n= 10,x =27.3,s*= 6.4 11n= 8,y =30.5,s*= 3.8 22若城镇职工可支配收入服从正态分布，试检验：（1）两次抽样调查结果的方差是否有显著差异？（2）两次抽样调查结果的数学期望是否有显著差异？（已知α= 0.05, F0.025(9,7) = 4.82, F0.975(9,7) = 0.283, t0.025(16) = 2.1199 ）。
2015年青岛大学818理论力学2015年考研专业课初试真题
三、 3 根杆 AB 、 AC 、 AD 铰接于 A 端，已知 OBAC 为正方形且水平，
B 、 C 、 D 均为光滑球形铰链，杆重不计。
1 kN 的重物， 于 A 端吊一重为 P＝ 求 AB 、AC 、
AD 杆所受的力。 （15 分）
1
四、轮 A 的半径为 r ，凸轮的半径为 R 2r ， 二轮间无相对滑动。已知凸轮以匀速 v 移动,当 AC 与水平面夹角为 60o 时。求杆 AB 的速度，加 速度。（25 分）
青岛大学 2015 年硕士研究生入学考试试题
科目代码：818 科目名称：理论力学 （共 3 页）
Hale Waihona Puke 请考生写明题号，将答案全部答在答题纸上，答在试卷上无效
一、 在图系结构中，已知力偶 M 作用在 DE 杆 上，尺寸如图，杆重不计，求 A、C 处的约束反 力。 （15 分）
二、 重为 P 2 4kN 的均质物块 B 其中心 B 与杆 AB 铰接，杆 AB 又与 杆 OA 铰接。若杆重不计，物块 B 地面之间的静滑动摩擦系数 铰 A 处吊一重为 Q 的物块。求平衡时 Q 的 最大值。 （20 分）
放。求释放瞬时，杆 AB 的角加速度、绳的张力 及地面反力。 （25 分）
2
七、图示结构由不计自重的弯杆 OAB、CD 及直杆 BC 组成。尺寸及荷载如 图所示。各铰 O、B、C、D 均光滑。试用虚位移原理求支座 C 处的约束反 力及 BC 杆所受的力。 （25 分）
3
五、 牛头刨床机构如图所示。 已知 O1 A 200mm ， 其转动角速度 ＝2 rad s 。求图示位置瞬时滑枕
CD 的速度、加速度。 （25 分）
六、如图质量 m 50kg ，长 l1 2.5m 的均质杆
机械控制工程基础习题试题及其答案.doc
机械控制工程基础习题试题及其答案。
1.简短回答问题1.控制系统的基本要求。
1)简要描述闭环控制系统的组成。
测量元件、给定元件、比较元件、放大元件、执行元件、校正元件2)和非最小相位系统的特性是什么，与最小相位系统有什么不同？第二个问题是复杂的平面【s】右半平面没有极点和零点的传递函数称为最小相位传递函数。
相反，在【s】在右半平面有极点和零点的传递函数称为非最小相位传递函数。
具有最小相位传递函数的系统统称为最小相位系统，而具有非最小相位传递函数的系统称为最小相位系统。
简述了系统串联滞后校正网络的校正原理。
该迟滞校正环节是一个低通滤波器，因为当频率高于1/T时，增益全部降低20gb(db)，但相位几乎没有降低。
如果这个频率范围内的增益增加到原来的直接增益，当然低频带的增益也会增加。
4)简述系统导线校正网络的校正原理。
对数幅频特性曲线上有20db/dec段，因此系统的剪切频率Wc、谐振频率Wr和截止频率Wb增加。
结果，系统的带宽增加，系统的响应速度加快。
此外，由于相位提前，相位裕量也可能增加，导致系统的相位稳定性增加。
5)减少或消除系统稳态误差的主要措施是什么？1:在扰动前增加系统开环增益或系统前向通道增益2:在系统的前向信道或主反馈信道上设置串联集成链路3:采用串级控制抑制内环干扰。
6)简要说明比例积分微分PID控制律中P、I和D的作用(1)比例系数Kp直接决定控制函数的强度。
增加Kp可以减小系统的稳定性误差，提高系统的动态响应速度。
然而，过大的Kp会恶化动态品质，导致被控量振荡，甚至导致闭环系统的不稳定。
(2)在比例调节的基础上增加积分控制，可以消除系统的稳态误差。
因为只要有偏差，其积分产生的控制量总是用于消除稳态误差，并且控制功能不会停止，直到积分达到零。
(3)微分的控制功能与偏差的变化速度有关。
2.已知控制系统的结构图如下图所示，计算如下:s-1，简短回答1.控制系统的基本要求。
1)简要描述闭环控制系统的组成。
青岛大学物理基础综合考研真题2015年、2017年
青岛大学2015年硕士研究生入学考试试题 科目代码： 913 科目名称： 物理基础综合 （共2页） 请考生写明题号，将答案全部答在答题纸上，答在试卷上无效1、质点由坐标原点出发时开始计时，沿x 轴运动，其速度12-=t v x 。
求：（1）瞬时加速度随时间的变化规律；（2）质点的运动学方程；（3）01=t到12=t 时间内质点的位移，以及运动的路程。
（15分）2、天平左端挂一定滑轮，一轻绳跨过滑轮，绳的两端分别系上质量为1m 、2m 的物体（21m m ≠）。
天平右端的托盘内放有砝码。
问天平托盘和砝码共重若干，才能保持天平平衡？不计滑轮和绳的质量及轴承摩擦，绳不伸长。
（15分）3、质量M 的物块与弹簧（劲度系数为k ）原来处于静止，另一质量为m 的质点从离M 为h 的高度自由落下，m 和M 做完全非弹性碰撞。
证明：弹簧对地面的最大压力为gm M kh mg g m M F )(21)(max ++++= （15分）4、如图所示，一长为l ，质量为M 的杆可绕支点O 自由转动。
一质量为m 、速度为v 的子弹射入下端而不复出，此后杆摆至水平位置又开始回落；设从子弹射入到停在杆内为时极短。
求：（1）子弹进入杆前的速度；（2）子弹刚停在杆内时轴O 受杆的力。
（15分）5、空间有两块面积为S 的平行放置的金属平板A 和B ，两板长宽均比板间距离大得多，如图所示。
令每板带上A q 及B q 的电量，求每板表面的电荷密度。
（15分）6、半径为R 的金属球带电荷Q ，球外套一个同心球壳的均匀电介质，其内外半径分别为a 和b ，相对介电常数为r ε（如图所示）。
求：（1）介质球壳内外的电场强度E 和电位移D ；（2）导体球的电位。
（15分）7、把能量为E 的电子射入磁感应强度为B 的匀强磁场中，其速度矢量与B 成θ角，路径成螺旋线，其轴在B 的方向。
试求这螺旋线运动的周期T ，螺距h 和半径r 。
（15分）8、一长直导线中通有I 的电流，在与其相距d 处放有一矩形线圈，线圈以速度v 沿垂直长直导线的方向向右离开导线时，线圈中的感应电动势是多少？指出感应电流方向。
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青岛大学2015年硕士研究生入学考试试题
科目代码：821 科目名称：机械控制工程基础（共3页）请考生写明题号，将答案全部写在答题纸上，答在试卷上无效一．分析图示钢板厚度控制系统工作原理并绘制系统功能框图。
（20分）
二．求图示机械系统的微分方程。
图中M为输入转矩,θ为输出转角，Cm 为圆周阻尼,J为转动惯量(20分)
三．基于方框图简化法则，求图示系统的闭环传递函数。
（15分）
四．对图示系统，要使系统的最大超调量等于0.2，峰值时间等于1s ，试确定增益K 和K h 的数值，并确定此时系统的上升时间t r 和调整时间t s 。
（15分）
五．对图示控制系统，求输入x i (t )=1(t )，扰动n (t )=1(t )时，系统的总稳态误差。
（15分）
六．
（15分）
（15分） 七．已知系统开环传递函数)
15)(12)(1(20)()(+++=s s s s H s G ,应用Nyquist 判据判别闭环系统的稳定性。
若不稳定，闭环系统有几个正实部的根? (15分)
八．设控制系统如下图所示k=10，试
1）画出系统开环BODE 图（10分）；
2）求出系统的相位裕度和幅值裕度（10分）。