毕业设计英文
毕业设计 英文资料
Compensation of Control System1．Multiple Constrains in DesignThe performance of a feedback control system is of primary importance.We have found that a suitable control system should have some of the following properties.1)It should be stable and present acceptable response to inputcommand,i.e,the controlled variable should follow the changes in the input at a suitable speed without unduly large oscillations or overshoots.2)It should operate with as little error as possible.3)It should be able to mitigate the effect of undesirabledisturbances.A feedback control system that provided an optimum perfprmance without any necessary adjustments is rare ually it is necessary to compromise among the many conflicting and demanding specifications and to adjust the system parameters to provide a suitable and acceptable performance when it is not possible to obtain all the desired optimum specifications.The preceding chapters have showen that it is often possible to adjust the system parameters in order to provide the desired system response.When the achievement of a simple performance requirement may be met by selecting a particular value of K, the process is called gain compensation.However,we often find that it is not sufficient to adjust a system parameter and thus obtain the desired performance.Rather we are required to reconsider the structure of the system and redesign the system in order to obtain a suitable one.That is ,we must examine scheme of the system and obtain a new design that results in a suitable system.Thus the design of a control system is concerned with the arrangement of the systemstructure and the selection of suitable components and parameters.When we are not able to relax several perfprmance requirements,we must alter the system in some way.The alteration or adjustment of a control system in oreder to provider a suitable performance is called compensation.In redesigning a control system to alter the system response,an additional component or device is inserted within the structure of the feedback system to compensate for the performance deficiency.The compensating device may be electric,mechanical,hydraulic,pneumatic,or some other type of devices or networks and is often called a monly an electric network serves as a compensator in many control systems.Quite often,in practice,the best and simplest way to improve the performance of a control system is to alter,if possible,the plant itself.That is,if the system designer is able to specify and alter the design of the plant,then the performance of the system may be readily improved.For example,to improve the transient behavior of a servomechanism position controller,we often can choose a better motor for the system.Thus a control system designer should recognize that an alteration of the plant maybe result in an improved system.However,often the plant is unalterable or has been altered as much as possible and still result in unsatisfactory performance.Then the addition of compensator becomes useful for improving the performance of the system.2．Types of CompensationThe compensator is placed in a suitable location within the system,and can be done in several ways .An additional component may be interested in the forward path.This is called the cascade or serial compensation.The transfer function of the compensator is designated as Gc(s),whereas that of the original plant(or process)is denoted by Gp(s).Alternatively,the compensator may be placed in the feedbackpath .This is called the feedback compensation. A combination of these two schemes.The selection of the compensation scheme depends upon a consideration of the specifications, the power levels at various signal nodes in the system,and the compensators available for us.3.Cascade CompensationAlthough many different types of compensators can be used,the simplest among them are cascade phase-lead,phase-lag,and phase-lag-lead networks.Each of these can be realized by using an operational amplifier network.The Bode diagram is used to determine a suitable cascade compensator in preference to other frequence plots.The frequence response of the cascade compensator is added to the frequency response of the uncompensated system.It is assumed, in below discussion, that the compensator Gc(s),is used with an uncompensated system so that the overall open-loop gain can be set to satisfy the steady-state error requirement,then Gc(s) is used to adjust the system dynamics favorably without affecting the steady-stste error.For convenience,the open-loop transfer function of the uncompensated system,Gp(s)H(s),is denoted by Go(s).At first,consider a system described by the open-loop transfer functionGo(s)=k/s(0.2s+1)Suppose we wish the closed-loop system to meet the following performance requirements:a)The steady-state error for a unit ramp is to be no more than 0.00316.b)The phase margin is to be no less than 45.For the first requirement,the static velocity error constant can be cocalculated from equationεss=1/Kv=1/K≦0.00316and thus the required open-loop gain is K=Kv=3.16It may also be seen that the phase margin will be about 45.at w=5 rad/s;therefore,to meet the second requirement,the magnitude must be zero at this frequency.Obviously,it is not possible to satisfy both system performance requirements with a singular value of gain.The system needs to be modified in some way,i.e,the shape of the Bode diagram has to be altered in some way to allow it to achieve both perfprmance requirements. The system perfprmance requirements stated in the example are typical of those found in many design cases;a steady-state error determines one value of gain while a desired transient response determines anthor.Note how each requirement relates to a different region of frequency acxis in the Bode diagram.(1)The steady-state error relates to the slope and magnitude at lowfrequency.(2)The phase margin relates to the gain crossover frequency,which usuallyoccurs at higher frequency.4．Approaches to System DesignThe performance of a control system can be specified by requirement of certain maximum overshoot and setting time for a step input. Furthermore it is usually necessary to specify the maximum allowable steady-state error for several test signal inputs and disturbances .These performance specifications are related to the location of the poles and zeros of the closed-loop transfer function.Thus the location of the closed-loop poles and zeros can be specified.As we found in chapter4,the locus of the roots of the closed-loop system can be readily obtained for the variation of one system parameter.However,when the locus of roots does not result in a suitable root configuration,we must add a compensator to alter the locus of the roots as parameter is varied.Therefore we can use the root locus method and determine a suitsble compensator transfer function so that the resultant root ;ocus yields the desired closed-looproot configuration.Alternatively,the performance of a control system can be specified in terms of the relative resonant peak,resonant frequency,and bandwidth of the closed-loop frequency response,or in terms of the phase margin, gain margin and gain crossover frequency of the open-loop frequency response.We can add a suitable compensator,if necessary,in order to satisfy the system perfprmancr.The design of the compensator is developed in terms of the frequency response as portrayed on the polar plot,the Bode diagram,or the Nichols chart.Because a cascade transfer function is readily accounted for on a Bode diagram by adding the frequency response of the compensator,we usually prefer to approach the frequency response method by utilizing the Bode diagram.5．Phase-Lead Compensation1. Phase-Lead CompensationThe phase-lead compensator is a form of high-pass filter,through which the signals at high frequencies are amplified relatively than that at low frequencies.It introduces a gain at high frequencies,which in general is destabilizing.However,its positive phase angle is stablilzing .Hence,we must carefully choose two break frequencies so that the stabilizing effect of the positive phase angle is dominant.ments on the Applicability and ResultsPhase-lead compensation has some distinct advantages over other forms of compensation,wherease it may also be difficult to use .Some observations from the example just analyzed allow a few generalizations to be made regarding phase lead compensation.1)The phase-lead compensation method provides an additional phaselead to limit the system’s overshoot to a required value.2)The open-loop(and usually the closed-loop)bandwidths isincreased.This is usually beneficial since the inclusion ofhigher frequencies in the response results in a faster response.Itmay cause problem,however,if noise exists at the higherfrequencies.3)Problem may occur when the uncompensated phase plot has a steeoslope in the vicinity of φm.This occurs because,as the new gaincrossover point moves to the right ,larger and larger phase leadis required from the compensator,demanding very large value ofα.This is difficult to achieve when the compensator is realizedwith physical components.For this reason ,value of α>15 shouldbe avoided,and methods to compensate the system using othertechniques,such as phaselag,should be investigated.6．Phase-Lag Compensation1.Phase-Lag Compensation ProcessIn phase-lag compensation,the magnitude part of the uncompensated Bode diagram is attenuated in order to reduce the gain crossover frequency,thereby allowing the uncompensated phase plot to produce the necessary phase margin.The phase-lag compensator is used to provide an attenuation and therefore to lower the crossover frequency of the system.Furthermore,at lower crossover frequency,we usually find that the phase margin of the system is increased,and the specifications can be satisfied.Of cause,the influence of the phase lag caused by the compensator should be taken into ually,the lag phase is about 5~12 if the break frequency corresponding to the zero of the compensator is wz=(0.1~0.2)wc.ments on the Applicability and Results1)The phase-lag method provides the necessary damping ratio in orderto limit the overshoot to the required value.2)The compensation process is somewhat simpler than the phase-leadcompensation in that the selection of the break frequencies is not too critical.3)As can be seen from the compensated system,the phase-lag techniquereduces the open and hence the closed-loop bandwith,which results ina slower response.4)Unlike phase-lead compensation,theoretically,phase lag compensationmay change the phase margin by more than 90.7．Phase Lag-Lead CompensationIn the compensator design it is usual to assume that the two break frequencies of the lag portion are lower than the two break frequencies of the lead portion.Further features of the Bode diagram include the following.1)The magnitude at lower frequencies is 0 db while the magnitude athigher frequencies is 20lg(αβ)ually,the compensator provides attenuation only and no gain.2)The phase angle first lags and then leads ,but the high-andlow-frequency phases are both zeros.3)The maximum phase-lag and the maximum phase-lead occur between theirrespective break frequencies.The phase lag-lead compensator utilizes the best feature of the individual lag and lead portions,usually without their disadvantages.For example,the lag-lead compensation allows the introduction of phase lead to stabilize a system,while providing attenuation at higher frequencies to filter out noise.8．Feedback CompensationIn order to improve the system performances,besides the cascade compensation,the feedback compensation is often used as another scheme.By using local feedback compensation,almost same effect,as that of cascade compensation,can be obtained.Morever ,additional specific functions forimproving system perfprmance are obtained.。
毕业设计中英文翻译【范本模板】
英文The road (highway)The road is one kind of linear construction used for travel。
It is made of the roadbed，the road surface, the bridge, the culvert and the tunnel. In addition, it also has the crossing of lines, the protective project and the traffic engineering and the route facility。
The roadbed is the base of road surface, road shoulder，side slope, side ditch foundations. It is stone material structure, which is designed according to route's plane position .The roadbed, as the base of travel, must guarantee that it has the enough intensity and the stability that can prevent the water and other natural disaster from corroding.The road surface is the surface of road. It is single or complex structure built with mixture。
The road surface require being smooth，having enough intensity，good stability and anti—slippery function. The quality of road surface directly affects the safe, comfort and the traffic。
本科毕业设计英文翻译
翻译部分英文原文SELF-ADVANCING HYDRAULIC POWERED SUPPORTSModern longwall mining employs hydraulic powered supports at the face area . The support not only holds up the roof , pushes the face chain conveyor , and advances itself , but also provides a safe environment for all associated mining activities . Therefore its successful selection and application are the prerequisite for successful longwall mining . Furthermore , due to the large number of units required , the capital invested for the powered support usually accounts for more than half of the initial capital for a longwall face . Therefore both from technical and economic points of view , the powered support is a very important piece of equipment in a longwall face .The application of modern powered supports can be traced back to the early 1950’s . Since then , following its adoption in every part of the world , there have been countless models designed and manufactured in various countries . But unfortunately , there still is no uniform system of classification .A simplified classification is used in this section . since a powered support consists of four major components(i. e. , canopy , caving shield , hydraulic legs or props , and base plate ) , the ways by which they are interrelated are used for classification . In this respect , two factors are most important : (1) presence or absence of a caving shield - if a caving shield is included , the support is a “ shield ”type , otherwise , a frame or a chock ; (2) number and type of arranging the hydraulic legs - since support capacity is generally proportional to the number of hydraulic legs , it is important to specify the number of hydraulic legs that a support has . Furthermore , the way the hydraulic legs are installed is important ; for example , a vertical installation between the base and the canopy has the highest efficiency of application whereas an inclined installation between the base and the caving shield has the least efficiency in supporting the roof .Based on this concept , there are four types of powered support , that is , the frame , chock , shield , and chock shield , in order of evolution of their development . However , it must be noted that the trend of development in each type is such that it becomes less distinguishable in terms of application .The four types of roof supports can be obtained for either longwall retreating or advancing systems , and they are available in standard , one-web-back , and immediate forward support ( IFS ) versions .With the standard system , the winning machine takes a cut or a slice , and the armored face conveyor is pushed over by the hydraulic rams that are fixed to the support units . The support units then are advanced sequentially to the conveyor . With the one-web-back system , a support is set back from the conveyor by a device that automatically keeps the leading edge of the support at a fixed distance from the conveyor .This allows easy access through the face and employs the standard method of advancing ; i. e. , pushing the conveyor first , and then advancing the support .With the IFS system , the support unit is advanced to the conveyor immediately after the cutting machine has passed , and the forward canopy of the support unit is long enough to support both the recently and newly exposed roof sections . After the supports have been advanced , the conveyor is pushed over .FRAMEThe frame support is an extension of the single hydraulic props conventionally used underground . Thus it is the first type developed in modern self-advancing hydraulic powered supports .It involves setting up two hydraulic props or legs vertically in tandem that are connected at the top by a single or two segmented canopies .The two segmented canopies can be hinge-jointed at any point between the legs or in front of the front leg .The base of the two hydraulic legs may be a circular steel shoe welded at bottom of each leg or a solid base connecting both legs (Fig .8.8) .Generally , a frame support consists of two or three sets of hydraulic legs . The set moving first is the secondary set , the set moving later is the primary set .There is a double-acting ram installed between each set . The piston of the ram is connected to the secondary set and the cylinder to the primary set . During support advance ( Fig. 8.9) , the primary set is set against the roof while the secondary set is lowered and pushed forward by the piston . Having reached the new position , the secondary set is set against the roof while the primary set is lowered and pulled forward by the cylinder . The distance of each advance ranges from 20 to 36 in. (0.50~0.91m) .Fig . 8.8 Frame supporta-primary set b-secondary setA B CFig . 8.9 Method of advancing the frame supportThe frame support is very simple , but more flexible or less stable structurally . There are considerable uncovered spaces between the two pieces of canopy which allows broken roof rock to fall through . Consequently , the frame support is not suitable for a weak roof . Frames have become seldom used because they are less stable and require frequent maintenance .CHOCKIn a chock support , the canopy is a solid piece and the base may be either a solid piece or two separate parts connected by steel bars at the rear and / or the front ends . In both cases a large open space is left at the center for locating the double-acting hydraulic ram which is used to push and pull the chain conveyor and the chock in a whole unit ,respectively , a distinctive difference from the frame support . This setupdesigned for thin seams with two legs in the front and four legs in the rear , separated by awalkwa is also used in the shields and chock shields .Again , all hydraulic legs are installed vertically between the base and the canopy (Fig. 8. 10) . The number of legs ranges from three to six , but the four-leg chocks are by far the most popular ones . The six-leg chocks are y (Fig. 8.10c) . For the six-leg chocks , the canopy is generally hinge-jointed above the walkway . Most chock are also equipped with a gob window hanging at the rear end of the canopy . The gob window consists of several rectangular steel plates connected horizontally at both ends.A B CFig . 8.10 Schematics of various chock supportIn most chock supports , there are hinge joint connections between the legs and the canopy and between the legs and the base . But in order to increase the longitudinal stability , it is reinforced mostly with a box-shaped steel frame between the base and each leg . A leg restoring device is installed around each leg at the top of the box-shaped steel frame .The chocks are suitable for medium to hard roof . When the roof overhangs well into the gob and requires induced caving , the chocks can provide access to the gob .SHIELDShields , a new entry in the early seventies , are characterized by the addition of a caving shield at the rear end between the base and the canopy . The caving shields , which in general are inclined , are hinge-jointed to the canopy and the base making the shield a kinematically stable support , a major advantage over the frames and the chocks . It also completely seals off the gob and prevents rock debris from getting into the face side of the support . Thus the shield-supported face is generally clean .The hydraulic legs in the shields are generally inclined to provide more open space for traffic . Because the canopy , caving shield , and base are interconnected , it can well resist the horizontal force without bending the legs . Thus , unlike the solid constraint in the frame/ chock supports , the pin connections between the legs and the canopy ,and between the legs and the base in a shield support make it possible that the angle of inclination of the hydraulic legs varies with the mining heights . Since only the vertical component of hydraulic leg pressure is available for supporting theroof ,the actual loading capacity of the shield also varies with the mining heights .There are many variations of the shield supports . In the following ,six items areused to classify the shields , which enables a unified terminology to be developed for all kinds of shields . The types of motional traces of the canopy tip , leg positions and orientation , number of legs , canopy geometry , and other optional designs and devices can be clearly specified by the terminology .TYPES OF MOTIONAL TRACES FOR THE LEADING EDGE OF THE CANOPY.This is the most commonly recognized way of classifying the shield . Based on this criterion , there are three types , lemniscate , caliper , and ellipse (Fig. 8. 11) .A . Lemniscate.LB . Caliper.C C . Ellipse.EFig . 8.11 Three types of motional traces for leading edge of the shield canopyA . Lemniscate . This is the most popular type . The caving shield and the base are jointed by two lemniscate bars which have a total of four hinges . As the hydraulic legs are raised and lowered , the dimentions of the lemniscate bars are selected such that the leading edge of the canopy moves up and down nearly vertically , thus maintaining a nearly constant unsupported distance between the face-line and the leading edge of the canopy .This is a feature that is widely considered most desirable for good roof control . There are clear limits of mining height within which the leading edge of the canopy moves nearly vertically . These limits are strictly controlled by the dimentional and positional arrangements of the canopy , caving shield , lemniscate bars , and the base . Beyond these limits , the edges will move rapidly away from the face-line creating a large unsupported area .B . Caliper . In a caliper shield , the caving shield and the base are connected by a single hinge .When the hydraulic legs are raised , the leading edge of the canopy moves in an arc away from the face , thus increasing the unsupported area This is considered by most users the least desirable feature of the caliper shield But in practice if the seam thickness varies little , the dimentional and positional arrangement of canopy , caving shield , and the base can be so designed that the distance change of unsupported area will not be significant . On the other hand , when the legs are lowered , it reduces the unsupported area .C . Ellipse . In this type the caving shield and the base are so connected that when the hydraulic legs are moved up and down , the leading edge of the canopy follows an elliptical trace . This type is seldom used .CHOCK SHIELDThe chock shield combines the features of the chocks and the shields . As such it possesses the advantages of both .If all of the four or six legs are installed between the canopy and the base , it is called a chock shield . There are regular four or six-leg chock shields in which all legs are vertical and parallel . Others form V or X shapes . Some canopies are a single piece and some are two pieces with a hydraulic ram at the hinge joint . The chock shield has the highest supporting efficiency . They are suitable for hard roof .中文译文自移式液压支架液压支架广泛应用于现代长臂采煤工作面上。
毕业设计开题报告--英文
Understood on the international present mainstream the technology, the application system as well as our country transform the technological strength and the hardware facility as well as the expenditure which needs.
Construct Enviroment & Equioment
一．The background of research:
Our country heating area are general, the heating time is long, is day by day intense to the energy demand and is urgent, but by the tradition fossil energy primarily our country, the resources dries up day by day, the consumption is big, the pollution serious also cannot regenerate, the energy tense situation aggravating, this requests us to have to improve the heating way unceasingly, the technical method, uses the least energy to produce the greatest quantity of heat in order to.But concentrates heats is not high in our country's popular degree, the centralism heats the production technology is not extremely advanced, this requests us studies the use to this kind of technology and the form, our country's centralism heats only distributes in the city and developed cities, also only is uses the winter various each household bunker coal regarding not the developed area and the general countrysides to warm up, this is to the energy huge waste and the environmental pollution, is the transformation key point.Even if already uses the area which the centralism heated, also was the level is uneven, does things their own way, could not form the unified system, did the heat energy assignment to be uneven, the hot heat, cold cold, affected the efficiency seriously, thus it can be seen, carried on the transformation to the obsolete pipe network, carried on the promotion to the existing equipment, established widespread also the unified big centralism heating pipe network system imperative.
3000英文翻译 毕业设计
Chip STC12C5204AD I/O port configuration STC12C5204AD series microcontroller its all I/O ports are controlled by the software configuration into 4 kinds of work type 4 types are respectively: quasi two-way mouth (standard the 8051 output mode), push-pull output, only for input (high resistance) or open-drain output functions. Every mouth consists of two control register the relevant position control each pin type of work. STC12C5204AD series microcontroller to electricity reattachment shall prevail two-way mouth (standard the 8051 output mode) mode: 2V above high level, 0.8 V for low level below.1. Quasi two-way mouth output configurationQuasi two-way mouth output type can be used as output and input function but don't need to reconfigure mouth lines output state. This is because juncture lines output is 1 drive ability is very weak, allowing external devices will its down. When pins for low, it output driving ability, can absorb the considerable current. Quasi two-way mouth have 3 pull_up transistor adapted to different needs.In the three and one transistor, pull up transistor called weak on pull ", for 1 and paternal line registers itself pins for 1 open. This pull_up provides basic drive current make prospective two-way mouth for 1 output. If a pin for 1 and output by external devices to drop down to low, pull up close and weak "very weak pull_up" maintain open position, in order to put this pin for low, strong to pull the external devices must have enough power to make pin infused current threshold voltage of a voltage to the following.Article 2 pull_up transistors, called "extremely weak on pull", 1 latch paternal line when open. When pin, the very weak suspended the pull_up source generates very weak and current will pin and high level.Article 3 pull_up transistor called "powerful pull". Juncture line latches from 0 to 1, the jumping to accelerate must pull up by logic 0 to two-way mouth logic 1 conversion. When this happened, powerful pull open about 2 machine cycle to make pins can quickly pull to the earth high level.Quasi two-way mouth output shown below.STC12C520 series microcontroller 3V device, if the user is in pins plus 5V voltage, there will be a current flow from pins, this has caused additional VDD power consumption. Accordingly, the proposal is not in quasi two-way mouth mode 3V microcontroller pins to exert 5V voltage, such as the use of words, will add current limiting resistor, or using diode do input isolation, or use triode do output segregation.Quasi two-way mouth with a schmidt trigger input and a interference suppression circuit.2. The push-pull output configurationThe drop-down push-pull output configuration open-drain output and the structure and the prospective two-way mouth down same structure, but when latches is 1 provides continuous strong pull up. The push-pull model need more commonly used for driving current situation.The push-pull pins configuration are shown below.3. Only for input (high resistance) configurationInput port configuration are shown below.Input port with a schmidt trigger input and a interference suppression circuit.4. Open-drain output configurationJuncture line latches is 0, the open-drain output close all pull_up transistors. When, as a logical output, this configuration mode must have externally pull, usually by resistance receiving V D D outside. This style of drop-down and quasi two-way mouth the same. The jammer line configuration are shown below.Open-drain port with a schmidt trigger input and a interference suppression circuit.A typical transistor control circuitIf use weak pull_up control, suggestion plus pull-up resistors R1 (3.3 K ~ 10K), if not add pull-up resistors R 1 (3.3 K ~ 10K), suggest R2 value in the 15K above, or use a strong push-pull output.STC12C5204AD series microcontroller programmable counter array(PCA)PCA contains a special 16 timer, has four 16 bits of capture/comparison of module and connected. Each module programmable workIn four mode: increase/decrease along the capture, software timer, high-speed output or could be modulated pulse output. Modules connected to P3.7 (0 CEX0 / PCA0 / PWM0), module 1 connected to P3.5 (CEX1 / PCA1 / PWM1), modules connected to P2.0 (2 CEX2 / PCA2 / PWM2), modules connected to P2.4 (3 CEX3 / PCA3 / PWM3). Register the content of CH and CL is free of 16 PCA increasing count the value of the timer. PCA timer is four modules, the public time benchmark by programming work .Programmable Counter ArrayPCA Timer/CounterCMOD SFR there are 2 bytes and PCA related. They were: CIDL, idle mode allows stop PCA; ECF, buy a, enabling PCA interrupt, when PCA timer spillover will PCA counting overflow marks CCON SFR (CF) buy bits.CCON SFR contains PCA operating control bits (CR) and PCA timer mark (CF) and symbol of each module CCF3 / CCF2 (CCF0). CCF1 / / Through the software for a CR bits (CCON. 6) to run PCA. CR bit is reset when PCA closed. When PCA counteroverflow, CF patients (CCON. 7) buy a, if CMOD register, it produces ECF position a disruption. CF bits can only through software cleared. CCON register a 0 ~ 3 is PCA modules logo (a 0 0, a corresponding module 1 corresponding module 1, bits 2 corresponding module 2, a 3 corresponding module 3), when there is a match or by hardware buy a comparisons. These signals are the only through software cleared.PCA capture of patterningIf CCON SFR bits of the throne of CCFn and CCAPMn SFR ECCFn bit is set position, will produce the interruption.A software timer modeThrough the CCAPMn registers for a ECOM and MA T bits, can make the PCA module used for software timer (below). PCA timer values and module of the register compared to capture, when both values equal, if a CCON SFR in CCFn (in) and a ECCFn CCAPMn SFR) in all buy bits, will produce the interruption.PCA Software Timer Mode/Software Timer model/PCA comparative ModePCA Software Timer Mode/Software Timer model/PCA comparative ModeHigh-speed output modelThis model (below), when PCA counter plan of the numerical and module capture registers matching, PCA value CEXn output will happen module of the flip. To activate the high-speed output modes of CCAPMn TOG SFR, modules, MAT and ECOM bit must buy bits.PCA High - Speed, Output Mode/PCA high-speed Output ModeIn use PCA high-speed output mode special application note:If a certain PCA module working in high speed pulse output mode, want to use software output change the same group of other common I/O port state, need to do first, whether CCAPnH judge CH is equal to abide, can freely modify, if equal, and determineCCAPnL circumstances > CL is allowed to change the same group of other common I/O port state. If use P3.7 / PCA0 / PWM0 do PCA high-speed pulse output, and the program inside and with software output change when the state P3.4 mouth, you need to do judgment.When one has the PCA high-speed pulse output function of I/O mouth working in high speed pulse output mode, if the software for the same group of other I/O port operation, if meet PCA comparator matching, this operation can change the pulse output function with PCA high-speed mouth of the I/O.PCA PWM mode/modulation pulse width output modeSince all share only PCA timer modules, all their output frequency is same. The output of each module 390v is independent of the changes, and using EPCnL, captured CCAPnL}} {of registers concerned. When CL SFR value is less than CCAPnL}} {EPCnL, when output is low, and the value of SFR when PCA CL is equal to or greater than EPCnL, CCAPnL}} {, the output as high. When the value of the CL by FF into EPCnH, 00 overflow, CCAPnH}} {the contents of EPCnL, loaded into the CCAPnL}} {. In this way, can realize update PWM without interference. To make CCAPMn PWM mode, module can PWMn and ECOMn bits of the register to buy bits.译文芯片STC12C5204AD的I/O口配置STC12C5204AD系列单片机其所有I/O口均可由软件配置成4 种工作类型4 种类型分别为：准双向口（标准8051输出模式）、推挽输出、仅为输入（高阻）或开漏输出功能。
毕业设计英文作文范文
毕业设计英文作文范文Title: The Importance of the Graduation Project in Academic Development。
The graduation project holds a pivotal role in the academic journey of students. It serves as a culmination of years of learning, a platform to showcase acquired skills, and an opportunity to delve deep into a specific subject matter. In this essay, I will elaborate on the significance of the graduation project and its impact on academic development.Firstly, the graduation project fosters independent learning and critical thinking skills. Unlike regular coursework where the parameters are often well-defined, the graduation project requires students to identify a research question or a problem statement independently. This process necessitates thorough literature review, data collection, and analysis, thereby honing research and analytical abilities. Moreover, formulating hypotheses, designingexperiments, or proposing solutions demand creativethinking and problem-solving skills, which are essentialfor academic and professional success.Secondly, the graduation project encourages interdisciplinary learning and collaboration. Many projects involve aspects from various fields, prompting students to integrate knowledge acquired from different courses. This interdisciplinary approach not only enriches the project but also broadens students' perspectives, enabling them to appreciate the interconnectedness of different subjects. Furthermore, collaboration with peers, mentors, or industry professionals enhances teamwork, communication, and project management skills, which are indispensable in any academic or professional setting.Additionally, the graduation project cultivates resilience and perseverance. Research, by its nature, is fraught with challenges, setbacks, and uncertainties. Students encounter obstacles ranging from experimental failures to data inconsistencies, requiring them to adapt, troubleshoot, and persist in the face of adversity.Overcoming these hurdles instills resilience and fortitude, attributes that are invaluable not only in academia but also in life.Moreover, the graduation project offers a platform for personal and intellectual growth. It provides students with the autonomy to explore topics of their interest, delveinto uncharted territories, and push the boundaries of knowledge. This journey of self-discovery not only enhances academic curiosity but also fosters a sense of ownership and accomplishment. Furthermore, presenting findings, defending arguments, and receiving feedback during project evaluations contribute to the development of presentation, communication, and critical evaluation skills, which are essential for academic and professional success.In conclusion, the graduation project is a cornerstone of academic development, offering students a unique opportunity to apply theoretical knowledge to real-world problems, fostering independent learning, interdisciplinary collaboration, resilience, and personal growth. By engaging in this endeavor, students not only demonstrate theiracademic prowess but also equip themselves with essential skills and attributes for future endeavors. Therefore, the graduation project stands as a testament to the culmination of academic journey and the beginning of a new chapter in students' intellectual and professional pursuits.。
毕业设计作品英文
毕业设计作品英文Graduation ProjectThe completion of a graduation project is a significant milestone in the academic journey of a student. It represents the culmination of years of hard work, dedication, and the acquisition of knowledge and skills. The graduation project serves as a platform for students to demonstrate their mastery of a particular subject or field, and to showcase their ability to conduct independent research, analyze data, and present their findings in a coherent and compelling manner.The process of undertaking a graduation project is often a challenging and rewarding experience. It requires students to delve deeply into a topic of their choice, to critically analyze existing research and theories, and to develop their own unique perspectives and solutions. Throughout this process, students are expected to work closely with faculty advisors, who provide guidance, support, and feedback to ensure the success of the project.One of the key aspects of a graduation project is the ability toconduct thorough and rigorous research. This involves reviewing relevant literature, identifying gaps in existing knowledge, and formulating a research question or hypothesis that can be explored through empirical investigation. Students must then design and implement a research methodology that is appropriate for their topic, and collect and analyze data using a variety of qualitative and quantitative techniques.In addition to research skills, the graduation project also requires strong writing and communication abilities. Students must be able to articulate their ideas clearly and concisely, and to present their findings in a well-organized and coherent manner. This often involves the creation of a written thesis or dissertation, as well as the development of visual aids and presentations that can be used to effectively communicate their work to a wider audience.Throughout the graduation project process, students are also expected to demonstrate their ability to think critically and to solve complex problems. This may involve the development of innovative solutions to real-world challenges, or the application of theoretical concepts to practical scenarios. By engaging in this process, students gain valuable experience in problem-solving, decision-making, and critical thinking, all of which are essential skills for success in their future careers.One of the most rewarding aspects of the graduation project is the opportunity for students to make a meaningful contribution to their field of study. Through their research and analysis, students may uncover new insights or develop novel approaches that can be applied to address pressing social, economic, or environmental issues. This sense of making a difference can be a powerful motivator for students, and can inspire them to continue pursuing their passions and interests long after the completion of their graduation project.Despite the challenges and demands of the graduation project, many students find the experience to be deeply fulfilling and transformative. The process of conducting independent research, developing new skills, and presenting their work to a wider audience can be a source of immense pride and accomplishment. Moreover, the skills and knowledge gained through the graduation project can serve as a foundation for future academic and professional pursuits, and can open up a world of new opportunities for students as they embark on the next chapter of their lives.In conclusion, the graduation project is a crucial component of the academic experience, one that challenges students to push the boundaries of their knowledge and capabilities. Through this process, students develop a deeper understanding of their chosen field, hone their critical thinking and problem-solving skills, and make ameaningful contribution to the broader academic and professional community. For those who embrace the challenges and opportunities of the graduation project, the rewards can be truly transformative, shaping their future trajectories and opening up new avenues for personal and professional growth.。
毕业设计 英文
毕业设计英文Graduation ProjectIntroduction:The graduation project is an essential part of completing our education. It is a significant milestone in our academic journey and an opportunity to showcase our skills and knowledge in a particular field. In this project, I will outline the details of my chosen graduation project.Objective:The main objective of my graduation project is to design and develop a mobile application that will assist users in managing their personal finance effectively. This application will provide a range of features and tools that will enable users to track their expenses, create budgets, and set savings goals.Project Description:The mobile application will be developed for both iOS and Android platforms, ensuring compatibility with a wide range of devices. The user interface will be intuitive and user-friendly, allowing users to easily navigate through the app's features. The application will require users to create an account to access its functionalities securely.Features:1. Expense Tracking: Users will be able to add their daily expenses and categorize them based on different predefined categories, such as food, transportation, entertainment, etc. The app will display the total expenses, along with a breakdown of expenses by category,enabling users to identify areas for potential cost-cutting.2. Budget Creation: The application will allow users to set monthly budgets for different expense categories. Users will receive notifications when they exceed their budget limits, reminding them to manage their spending efficiently.3. Savings Goals: Users can set savings goals based on their financial targets. The app will track their progress towards achieving these goals, providing visual representations of their savings growth and estimating the time required to reach their objectives.4. Transaction History: Users will have access to a transaction history that will allow them to review their past expenses and monitor their financial activities over time. This feature will provide users with a comprehensive overview of their spending habits.Conclusion:The development of this mobile application will provide users with a useful tool for managing their personal finance. In an increasingly digital world, it is crucial to leverage technology to streamline and optimize our financial management processes. This graduation project will not only enhance my technical skills but also contribute to society by providing a practical solution for individuals to improve their financial well-being.。
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毕业设计英文篇一：毕业设计英文翻译使用高级分析法的钢框架创新设计1．导言在美国，钢结构设计方法包括允许应力设计法(ASD)，塑性设计法(PD)和荷载阻力系数设计法(LRFD)。
在允许应力设计中，应力计算基于一阶弹性分析，而几何非线性影响则隐含在细部设计方程中。
在塑性设计中，结构分析中使用的是一阶塑性铰分析。
塑性设计使整个结构体系的弹性力重新分配。
尽管几何非线性和逐步高产效应并不在塑性设计之中，但它们近似细部设计方程。
在荷载和阻力系数设计中，含放大系数的一阶弹性分析或单纯的二阶弹性分析被用于几何非线性分析，而梁柱的极限强度隐藏在互动设计方程。
所有三个设计方法需要独立进行检查，包括系数K计算。
在下面，对荷载抗力系数设计法的特点进行了简要介绍。
结构系统内的内力及稳定性和它的构件是相关的，但目前美国钢结构协会（AISC）的荷载抗力系数规范把这种分开来处理的。
在目前的实际应用中，结构体系和它构件的相互影响反映在有效长度这一因素上。
这一点在社会科学研究技术备忘录第五录摘录中有描述。
尽管结构最大内力和构件最大内力是相互依存的（但不一定共存），应当承认，严格考虑这种相互依存关系，很多结构是不实际的。
与此同时，众所周知当遇到复杂框架设计中试图在柱设计时自动弥补整个结构的不稳定（例如通过调整柱的有效长度）是很困难的。
因此，社会科学研究委员会建议在实际设计中，这两方面应单独考虑单独构件的稳定性和结构的基础及结构整体稳定性。
图28.1就是这种方法的间接分析和设计方法。
在目前的美国钢结构协会荷载抗力系数规范中，分析结构体系的方法是一阶弹性分析或二阶弹性分析。
在使用一阶弹性分析时，考虑到二阶效果，一阶力矩都是由B1,B2系数放大。
在规范中，所有细部都是从结构体系中独立出来，他们通过细部内力曲线和规范给出的那些隐含二阶效应，非弹性，残余应力和挠度的相互作用设计的。
理论解答和实验性数据的拟合曲线得到了柱曲线和梁曲线，同时Kanchanalai 发现的所谓“精确”塑性区解决方案的拟合曲线确定了梁柱相互作用方程。
为了证明单个细部内力对整个结构体系的影响，使用了有效长度系数，如图28.2所示。
有效长度方法为框架结构提供了一个良好的设计。
然而，有效长度方法的使用存在着一些困难，如下所述：1、有效长度的方法不能准确核算的结构系统及其细部之间的互相影响。
这是因为在一个大的结构体系中的相互作用太复杂不能简单地用有效长度系数K代表。
因此，这种方法不能准确地测算框架单元实际需要的强度。
2、有效长度的方法无法获取结构体系中内力非弹性再分配，因为带有B1、B2系数的一阶弹性分析只证明二阶影响，但不是非弹性内力再分配。
有效长度的方法只是保守的估计了最终承载大型结构体系的能力。
3、有效长度方法无法测算的结构体系受负荷载下的失效模式。
这是因为荷载抗力系数相互作用方程不提供在任何负载下结构体系的失效模式的信息。
4、有效长度的方法与计算机程序不兼容。
5、有效长度的方法在涉及系数K的单独构件能力检测时需要耗费比较长的时间。
随着电脑技术的发展，细部结构的稳定性和整体结构的稳定性这两个方面，可以通过结构的最大强度测定来被严格对待。
图28.1就是这种方法的间接分析和设计方法。
直接设计方法的发展被称为高级分析，或者更具体地说，二阶弹性分析框架设计。
用这种直接的方式，无须计算有效长度系数，因为不需要规范方程包含的单独构件能力检测。
凭借目前现有的计算技术，直接使用高级分析法技术框架设计是可行的。
这种方法过去在办公室设计使用时一直被认为是不切实际的。
本章的目的是提出一个切实可行的，直接的钢框架设计方法，使用高级分析法产生跟荷载抗力系数法的相同的结果。
利用高级设计分析的优点概述如下：1、高级分析法是结构工程师进行钢结构设计的另一个工具，它的通过不是强制性的，而是为设计人员提供灵活的选择。
2、高级分析法直接获取了整个结构体系和细部结构极限状态的强度和稳定性，这样就不需要规范方程包含的单独构件能力检测。
3、相比荷载阻力系数设计法和允许应力设计法，高级分析法通过直接弹性二阶分析提供了更多结构性能的信息。
4、高级分析法解决了常规荷载阻力系数设计法中由于不兼容弹性全球分析和单元极限状态设计的困难。
5、高级分析法与计算机程序兼容性良好，但荷载阻力系数设计法和允许应力设计法则无法与计算机程序兼容，因为它们在过程中都需要有对系数K的单独构件能力检测的计算。
6、高级分析法可以得到整个结构体系弹性内力再分配的结果，并且节约高度不确定的钢框架的材料。
7、过去在设计室使用高级分析法被认为不切实际，而现在则是可行的，因为个人电脑和工程工作站的能力正在迅速提高。
8、通过高级分析法测定的各项数据都接近了荷载抗力系数法测定的那些数据，因为高级分析法对荷载抗力系数法的柱曲线和梁柱的相互作用方程进行了校准。
因此，高级分析法替代了荷载抗力系数法。
9、高级分析法比较高效，因为它完全消除了经常引起混淆的冗长的单独构件能力检测，包括荷载阻力系数设计法和允许应力设计法中的系数K的计算。
在各种高级分析法中，包括塑性区准塑性铰法，弹性区塑性铰法，名义负荷塑性铰法和改进塑性铰法，推荐使用改进塑性铰法，因为它保留了计算的效率和简便性及实际应用的准确度。
这个方法是对简单的传统的弹塑性铰法的改进。
其中包括一个简单的修改，证明在塑性铰位置截面刚度的逐步退化和包括细部两个塑性铰之间的逐步刚度退化。
表28.1中对常规荷载抗力系数法和高级实用性分析方法的关键因素做了比较。
荷载抗力系数方法用来证明主要影响隐含在其柱强度和梁柱相互作用方程之中，而高级分析法通过稳定性的功能，刚度退化的功能和几何缺陷方面来证明那些影响，在28.2中有详细讨论。
高级分析法持有许多钢结构实际问题的答案，同样地，我们推荐寻找有效地合理地完成框架设计方法提供给工程师，但这要符合荷载抗力系数规范。
在下面的章节里，我们将提出符合荷载抗力系数钢框架结构设计的高级先进实用分析方法。
该方法的有效性将通过比较基于精确塑性区解决方案和荷载抗力系数设计分析及设计结果的细部和框架的实际案例研究。
大范围的案例研究和比较可以这种高级方法的有效性。
2．高级实用性分析本节介绍了一种消除规范单独构件能力检测的直接设计钢框架的高级实用性分析方法。
改进后的塑性铰法是由简单的传统的弹塑性铰法发展调整而来，实现了简单和真实的反映了实际情况。
下一节将提供了最终确认该方法的有效性的核查方法。
高级分析能够验证连接的灵活性。
常规分析和钢结构的设计通常在假设梁柱连接不是完全刚性或理想的固定下进行。
然而，在大部分实际的连接是半刚性的并且它们的状态介于这两个极端的例子之间。
在允许应力设计-荷载抗力系数规范，有两类特定的建筑：FR（完全受限）结构和PR（部分受限）结构。
荷载抗力系数规范允许通过“合理途径”连接灵活性评估。
瞬间旋转的关系代表了连接的状态，已经完成多方面的试点连接工作和收集大批的瞬时旋转数据。
有了这个数据库，研究人员已经开发了数个连接模型，包括线性，多项式，B 曲线，动力和指数。
鉴于此，Kishi和Chen提出的三参数幂函数模型被采用了。
在使用高级分析时，几何缺陷必须由框架单元加以塑造。
几何缺陷在构造或架设过程中导致不可避免的错误。
对于建筑结构的结构构件，几何缺陷的种类属于非线性和非垂直的。
明确建模和等效名义载荷被研究人员用来证明几何缺陷。
在这一章节中，发展了基于进一步减小构件切线刚度的新方法。
这种方法提供了一种简易的途径用来证明没有输入名义载荷或明确几何缺陷的不完善的影响。
本节中描述的高级实用性分析方法仅限于受静载的两维支撑，无支撑，和半刚架。
不考虑结构的空间状态，并且假定有足够的侧向支撑防止侧扭屈曲。
假设W节就是这样的节可以在无局部屈曲情况下发挥全塑性时刻能力。
强轴和弱轴弯曲宽凸缘部分的研究都采用高级实用性分析方法。
该方法可被视为介于现在广泛使用的篇二：毕业设计英文翻译附录中南大学本科生毕业论文（设计）英文译文及原件题目Overlay Networks and the Future of theInternet 学生姓名迪丽努尔.阿不来提指导教师杨淑平学院数学科学与计算技术学院专业班级信息与计算科学0504班完成时间 XX年6月覆盖网和互联网的未来摘要近年来，我们在互联网上看到多种类型的所谓的“覆盖”网络的出现。
这样的覆盖网络有许多不同的例子，其中包括容量分发缓存网络，被公司生效像Akamai公司一样，点对点文件共享网络与应用软件，如BitTorrent公司，IP 语音服务通过Skype和各种试验网络，如PlanetLab 。
这种覆盖具有重要的技术和政策影响下一代互联网架构的发展。
本文提供如此的互联网架构重叠，工业结构和政策的第一次尝试理解的影响。
我们介绍了一种分类的思考这些规模和日益重要的互联网的一些覆盖例子，并提出一些工业结构和政策的覆盖当中所产生的初步的观点。
关键词：网络结构，覆盖网络，互联网服务供应商，互联网的政策。
互联网最早是以政府资助的研究网络上运行的顶部的公共交换电信网（ PSTN ）而出现的。
互联网是一个数据的应用，主要是不受管制，这是支持顶部的公共电话网络实用规范。
互联网是一个“覆盖网”，是基本基础设施的补充，是增加新功能的PSTN网（分组交换数据网）来支持研究团体的特殊需要（点对点计算机通信）。
大部分的增量投资，路由器，服务器和接入设备（电脑）进行了新类型的供应商（互联网服务供应商或互联网服务供应商）和最终用户（用户端设备或设备），来补充已在坐标上的PSTN基础设施。
在20世纪80年代，随着互联网的商业化以及90年代为宽带通信以大众市场平台的形式出现，互联网已经发展成为我们全球公共通信基础设施的主要平台。
逐渐地，IP数据包运输为电话和其它多媒体应用软件（语音，视频和数据）提供了基本的运输媒介，。
什么是“重叠网”应用已成为基本的基础设施。
随着时间，传统的PSTN供应商在管理基础设施和投资需要来支持互联网当中起着更大的作用。
反常，市场的扩大以及改革带来了更为复合和相互依存的互联网基础设施生态系统。
互联网的成功在很大程度上归功于互联网的互操作性和连接，这些由IP协议和坚持“端到端”（e2e）的设计原则的普遍存在的采取来支持的，那些设计原则支配互联网架构很长时间了。
然而，互联网的成功也引进了重大的问题。
发展带来了异构服务（不是每个人都需要或希望相同的功能） ;新的需要和要求（支持实时业务或增强的安全性） ;复杂性和规模问题（起因于今天的交通时期和连接的互联网衡量的巨大重要性）。
为了迎接这些挑战，互联网需要继续发展。
在这个过程中，有时看起来就像历史重演一样，目前互联网在大量生产自己的“重叠网”网络的收集。
这里有多种有关覆盖的类型和实例（见表1 ），以满足一系列的目的和需求（见下文的讨论）。