东南大学信息学院2012年MATLAB上机考试题及答案.doc

guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. 　　Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. 　　Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation the functions and priorities compared to the requirements of our gap is still very big. Main is daily in the passive meet of more, active research of less, service also has not timely, and not in place of problem; work in the meet Yu traditional of, and program of of work way, develop innovation spirit and service innovation capacity not strong; supervision information work and promoted decision implementation of contact enough close, feedback situation not active; research resources of using enough full, research results of into degree not high; some sector documents running not specification; Municipal Government Office on the County (district) and municipal government sector Office work of guide enough, No real form interaction and close collaboration, promote the implementation of the work. 　　These problems, we must effectively be addressed in the future work. Second, serve the overall situation, carry out their duties, improve quality, and strive to create a new situation of system of government offices in the city since last season, meeting the Secretary-General of the State Council and the provincial government has held a government system, from a global and strategic height, scientifically analyzed the new situation and the newTasks on the system of government offices bring new situations and new problems and new challenges, profoundly expounded the work of government departments at all levels in the new era should be put in the situation to understand, to grasp, to deploy at any time and under any circumstances, should always focus on the big picture, firmly grasp the overall situation, increasing in the overall implementing in earnest the work of spontaneity, initiativeSecondly, we should strengthen the team. A unit is a team in various sections of the unit inside is also a small team. A unit with a team spirit, formed a team responsibility, cohesion and competitiveness. You want to make a unit, a Department work improvement, must be melting inside a feeling of solidarity and mutual help, for a common goal and determined to achieve the spirit, cultivating a strong collective spirit and team responsibility, sense of honor. Therefore, we need to start improving office work and enhance the efficiency of Office work and strive to build a concerted ... Fault. In accordance with the requirements of modern management science, establishing strict responsibility system of management by objectives. A work who is in charge, who is in charge and who is responsible, what right do these people have, what responsibility, has to truthfully and clearly understood. Departments at all levels should strictly implement the check in the Office of party Committee evaluation, significant accountability and reward incentive system, pay close attention to duty cash and making unity, rights, responsibilities, and to inspire each of cadres spirit and morale, Super courage. Investee insists, is a deep topic, is a real problem, is a big issue. Today, I just combined this year, the city's Communist Party Committee Office, had some rough talk and understanding, we must strengthen research and exchanges in this regard in the future. 　Investee in the new year, we must hold high the banner of Deng Xiaoping theory and the "three represents" theory the great banner of, under the correct leadership of the CPC, adhere to the people-oriented, insist on truth, adhere first to excellence, efforts to do Office work to a new level. Speech at the Conference on the system of government offices in the city around the development of service function to create a new situation in the work of the Office of the city's system of Government--speech at the Conference on the system of government offices in the city
　　This system of government offices working in the city's main task is to study Government systems of administrative supervision, administrative information, administrative reception and information technology issues. For the meeting, the City Mayor Ma has made important instructions, the Municipal Government Office fully prepared brewing, combined with practical work to develop the notice on further strengthening the supervision work, the XX, Chief Information interim measures for 2005 and the city's system of Government Administration informatization construction task statement and other documents. Before the General Assembly and organization of counties (districts) of the scene to observe the Government Office, achieve the purpose of exchanges of work, thought. Today, the Tang Mayor also attended the meeting and delivered an important speech in the midst, hope good grasp of implementation. 　　Next, I would like to make a few remarks. 　　A, and around Center, looks at development, strengthened service, city government system Office work rendering atmosphere in recent years, city government system Office to
MATLAB上机测验题
（考试时间：2:20----4:20）
姓名 学号
考试要求：
1、要求独立完成不得与他人共享，答卷雷同将做不及格处理。
2、答卷用Word文件递交，文件名为学号+姓名.doc，试卷写上姓名及学号。
3、答卷内容包括：
（1） 程序；
（2） 运行结果及其分析；
（3） 图也要粘贴在文档中。

上机考题：
一、系统传递函数为，按照以下要求求解：
1） 求其极零点图，判断系统的稳定性，画出系统的频谱特性；
2） 当系统输入信号为：，时，画出系统的输出。

(1) 代码如下：
clc
clear
b=[1 1 0];
a=[1,-1,0.81];
sys=tf(b,a,-1);
figure
pzmap(sys);
saveas(gcf,'p1_1','bmp');
figure
w=0:0.1:20;
freqz(b,a,w);
saveas(gcf,'p1_2','bmp');
%第二问开始
figure;
n=0:50;
x=5+cos(0.2*pi*n)+2*sin(0.7*pi*n);
lsim(sys,x)
saveas(gcf,'p1_3','bmp');
运行结果如下：

图1-1

图1-2
系统极零图如图1-1所示，通过该离散系统的极零图可以看出，极点全部都在单位圆内，所以系统是稳定的。
系统的频谱特性曲线如图1-2所示
（2）运行结果如下图所示

图1-3
图1-3为系统在x(n)激励下的输出，其中灰色部分为输入信号，蓝色为输出信号。

二、系统传递函数为，
1) 画出系统的零极点图，判断稳定性；
2) 给定频率范围为[0,10]，步长为0.1，画出其频率响应；
3) 画出系统的单位脉冲响应。

（1）代码如下：
clc
clear
b=[1 11 30 0];
a=[1 9 45 97 50];
sys=tf(b,a);
figure
pzmap(sys);
saveas(gcf,'p2_1','bmp');
%第二问
figure
w=0:0.1:10;
freqs(b,a,w);
saveas(gcf,'p2_2','bmp');
%第三问
figure
impulse(sys);
saveas(gcf,'p2_3','bmp');

运行结果如下：

图2-1
极零图如上图所示，该连续系统的极点均在左半平面，所以系统稳定。
（2）系统的频率响应如下图所示：

图2-2
(3) 该系统的单位脉冲响应如下图所示：
图2-3
三、系统传递函数为，初始状态为，激励信号为，求系统的零输入、零状态和全响应。
由题目条件可以得到方程组：
q’’(0)+3q’(0)+2q(0)=0;
q’(0)+3q(0)=1;
q’’(0)+3q’(0)=2;
求得x0=[q’(0) q(0)]=[4 -1]
代码如下：
clc
clear
A=[1 3 2;0 1 3;1 1 0];
B=[0;1;2];
X=inv(A)*B; %求解方程组
x0=[X(2),X(3)];
figure
b=[1 3];
a=[1 3 2];
sys=tf(b,a);
[A B C D]=tf2ss(b,a);
sys=ss(A,B,C,D);
t=0:0.1:10;
z=zeros(size(t));
e=exp(-2*t).*(e(t)-e(t-6));
subplot(3,1,1);
lsim(sys,z,t,x0)
title('零输入响应')
subplot(3,1,2);
lsim(sys,e,t)
title('零状态响应')
subplot(3,1,3);
lsim(sys,e,t,x0);
title('全响应')
saveas(gcf,'p3_1','bmp');

运行结果如下：
图3-1

四、信号，以进行采样，N分别为(1)N＝70、(2)N＝200，给出两种条件下信号x(t)的频谱图(用FFT命令)，并分析差异以及产生差异的原因。
代码如下：
clc
clear
N=70; %第二次改为N=200
n=0:N-1;
t=0.01*n;
F=zeros(1,1000)
x=2*sin(4*pi*t)+5*cos(8*pi*t);
F(1:N)=x;
for i=1:N
w(i)=(i-1)*0.2*pi;
end
figure;
G=fft(F,N)/100;%取样间隔0.01s
subplot(2,1,1);
plot(abs(G),'r');xlabel('w');ylabel('G');
title(['N=',num2str(N)])
subplot(2,1,2)
plot(angle(G));xlabel('w');ylabel('Phi');
saveas(gcf,'p4_1','bmp'); %第二次改为p4_2

运行结果如下：

图4-1

图4-2
N=70和N=200相比较，N=200的频谱图像在频率边缘非常“陡”，产生了截断效应，原因是N=200时，原函数是周期函数。
在空气绝缘和气体绝缘设备中，都有沿固体表面放电的问题，因为高压导体总是需要用固体 绝缘材料来悬挂或支撑的，这种固体绝缘称为绝缘子.当满足某种特定的条件时绝缘子表面 的气体可能会沿绝缘子表面放电，沿整个固体表面发生放电时称为闪络and steadfastness. And explicitly put forward the "surrounding situation, pay attention to implementation" is the core of government offices, requiring government departments at all levels cannot be "Gramophone", "mail room" and "the Messenger" is not confined to paper communications, yinglaisongwang and upload issue. Must to has strongly of implementation consciousness, this is Government Office sector first bit of task, to first, and is duty-bound, insisted reported truth, and told truth, and out confess, and do facts, and pragmatic effect, put work of to points real put to research solution reform development stable in the of major problem Shang, put to research solution masses production life in the of urgent problem Shang, put to research solution work in the exists of highlight problem Shang, put an end to to Conference implement Conference, to file implementation file, never can makes superior of decision and deployment in a "implementation" Lost in the sound. 　　System Office of the Government sector must take the lead in party and Government policies, the deployment and carry out specific targets, in the implementation efforts, for example on the implementation, on the implementation of a performance. 　　City Government System Office to seriously implement implementation national, and Province Government system Secretary-General Office Director Conference spirit, according to around overall, grasp implementation this a general requirements, insisted reform innovation, further change management concept, and management functions, and management system and management method; insisted quality first, ensure for led, and for grass-roots, and for masses provides quality efficient service; insisted strictly rule political, efforts construction a support political firm, and business master, and service political clean, and style excellent of Office team. Concrete work, and must deal with "three relationships": one is to handle well the relationship between passive adaptation and active service. Office service functions to the passive aspect of its work, which requires us to host lead when action must be strictly in accordance with the intentions and requirements for leadership, work within the limits of delegated authority, not offside, participation in the intervention, and not decision-making, coordination is not contemplated. 　　Meanwhile, Office work and must become more conscious, give full play to the initiative and work to some foreseeable, be proactive, prepared, thinking ahead, providing information, active leadership, reflect the situation, ahead of good research, reference point, in key places to promote overall efficiency. Second, to handle the relationship between administrative services and transaction services. Administrative services and Services Office services complement the two aspects of the job. Administrative services is the core service is guaranteed. Note that combines both, adhere to government service as the main line, the Chief turns around the overall situation, turns around the district. On one hand, will attachthree a representative" important thought for guide, efforts adapted new situation, and new task, and new requirements, tightly around city reform development of overall, further change functions, strengthened service, determined to innovation, Government System Office overall work of quality and level has has new of improve, for city economic social development made has due of contribution. 1, staff assistant for further strengthening. Around the focus of leadership services, actively carry out research studies, for all levels of Government on the event, grab global proposed a number of solutions with a higher reference value recommendations provide a basis for improving government leadership. About development, adjustment of interest difficulty, people the focus of the problem, and give full play to the offices that are interlinked, dredge about, contact and coordination of functions, in order to reduce conflict, to avoid omissions, form a joint force, promoting the Government to play an active role in the work as a whole. 　　Working around Government Center implementation supervision intensified, broadened and improved efficiency, do check the fruit, fruit, assisting the Government in implementation of the Assistant role to play, a powerful impetus to the realization of the objectives of the Government. 2, the service areas to further expand. The full implementation of the open government pilot project, strengthening carrier construction, innovative forms of public, deepening public content, extends the open range, regulate public procedures, establishment of a city, County, Township and village-level administration system, to meet the people's right to know, creates conditions for the effective exercise of supervision. Development issued the XX, matters of significant public policy implementation measures, such as the question of hearing 6 system, open Government continues to promote in depth. Established opened the city (County) long public phones, solving a number of concern people's immediate interests and produce hot spots and difficult problems in life, by all sectors of the community alike. Universal Chief was built starting at the city and county levelsHall masses, serve the community for the Government to play a better Windows and tie. 　　With the system of Government Office for hub, connecting the County (district) and the departments of municipal government Web sites and Office decision-making service system has been built in the city, Government Office local area network established, significantly accelerate the pace of office automation and information network. 3, improved quality and productivity with new work. City levels Government Office put pursuit quality and efficiency as measure Office overall work level of important standard, pendulum in highlight location, around service overall, and pay close attention to the implementation this central, right processing inherited and innovation, and full and focus, and on Shang service and on Xia service of relationship, bold innovation, focused on effectiveness, presentation of policy sex, and targeted and