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1.
本文对web信息采集系统进行需求分析,描述了系统具有的功能,并分析了系统的功能需求和非功能需求。  相似文献   

2.
介绍了功能安全的定义和现有国际、国内功能安全标准,分析了进行系统功能安全测试的必要性。总结了系统功能安全测试的关键技术,包括基于功能安全的安全标准体系、安全完整性等级、整体安全生命周期。正在筹建的系统功能安全测试实验室将是一家开展系统功能安全测试的实验室。  相似文献   

3.
软件系统的非功能需求通常横切整个系统,采用面向对象的软件开发方法会导致代码缠结和分散.提出一种面向方面的非功能需求建模方法,通过扩展UML表达面向方面的概念,识别系统的功能需求和非功能需求,根据相应的需求得出系统的功能模型和非功能模型,然后将系统的非功能需求用方面实现,功能需求用组件实现,最后将组件和方面编织在一起形成最终的系统.这种方法降低了软件系统的开发难度,提高了系统的模块性、可重用性和可维护性.最后给出了应用实例.  相似文献   

4.
针对传统的矿井127 V综合保护系统保护距离短、稳定性差和显示不精确的问题,在分析系统应具备的保护功能和自检功能的基础上,设计了以C8051F020为核心的数字化矿井127 V综合保护系统,详细介绍了系统硬件电路设计和软件设计。该系统可对3个回路执行综合保护和控制功能,能满足长距离保护的要求,系统自检功能的设计减小了系统故障引发安全事故的几率。调试结果表明,该系统功能全、成本低,能够满足现代煤矿井下的需求。  相似文献   

5.
基于热轧水处理工艺流程特点,结合PCS7系统性能特点,从系统结构、软硬件配置和实现功能几方面阐述了自动控制系统的设计与实现,并着重论证了系统中的高压水泵自动控制,指出自动控制系统应是紧密结合工艺,集控制功能、管理功能和数据处理功能于一体的系统.  相似文献   

6.
庄景晖 《福建电脑》2014,(11):33-35
本文对高校的手机一卡通系统进行了研究,给出系统分布图和系统总体架构,分析了系统的软件体系架构,完成了系统主要模块功能和手机客户端主要模块功能的设计。  相似文献   

7.
介绍了教学课件网站的出现的背景及其特点。系统采用ASP技术开发,系统结构图则描述了系统的功能。着重阐述了课件下载功能和栏目管理功能的实现,最后总结了系统开发的全过程。  相似文献   

8.
现代企业在构建高效网络互连的时候,也更注重网络的安全,所以在企业的内部网实现脱离Internet的内网通信系统也是很有必要的。该系统实现了如下的功能:利用SWING技术和AWT技术实现系统的图形化界面。在用户列表面板上,提供了好友列表的显示和用户功能菜单;系统功能面板上提供了界面选择功能和IP范围搜索好友和自动添加好友功能;在系统设置面板上,主要提供了公共程序路径的更改和搜索好友的IP范围的设置。本系统采用JAVA语言开发,使用纯JAVA的内存数据库Derby作为系统后台和Eclipse开发环境,旨在提供一个功能全面、即时、高效的局域网通信系统。  相似文献   

9.
陈龙  张永军 《软件》2012,33(12)
本文针对自然灾害过后的广播需求,提出了一个基于无线网络的多功能应急信息采集与发布系统,此系统不仅实现了广播发布系统功能,并且将语音通话及环境监测功能融合进来,成为一个多功能应急系统.针对此系统,本文使用了嵌入式系统实现了网关部分进行验证,运用shell脚本技术实现对网关的配置管理,讨论了如何将广播及语音通话融合在一起,降低系统的复杂度,并对要实现的环境监测和通信功能进行了模块划分和实现.通过模拟实验场景,对系统功能进行了验证,得出系统从功能上可实现预期目标的结论,并对其中的问题进行了讨论.  相似文献   

10.
电子仪表系统(EIS)在飞机飞行和维护过程中对飞机性能参数的显示具有至关重要的作用;针对电子仪表系统的功能仿真,提出一种基于多Agent的EIS系统建模方案,对系统功能从整体角度进行了描述和分类,在功能分类的基础上进一步建立了层次化系统结构模型,并利用混合型Agent对系统功能对象的结构进行了设计,建立了系统功能行为模型;最后以发动机N1转速超限为例对上ECAM显示功能进行验证,证明该方法在飞机电子仪表系统仿真建模的实用性和可靠性。  相似文献   

11.
The new method of defuzzification of output parameters from the base of fuzzy rules for a Mamdani fuzzy controller is given in the paper. The peculiarity of the method is the usage of the universal equation for the area computation of the geometric shapes. During the realization of fuzzy inference linguistic terms, the structure changes from the triangular into a trapezoidal shape. That is why the universal equation is used. The method is limited and can be used only for the triangular and trapezoidal membership functions. Gaussian functions can also be used while modifying the proposed method. Traditional defuzzification models such as Middle of Maxima − MoM, First of Maxima − FoM, Last of Maxima − LoM, First of Suppport − FoS, Last of Support − LoS, Middle of Support − MoS, Center of Sums − CoS, Model of Height − MoH have a number of systematic errors: curse of dimensionality, partition of unity condition and absence of additivity. The above-mentioned methods can be seen as Center of Gravity − CoG, which has the same errors. These errors lead to the fact that accuracy of fuzzy systems decreases, because during the training root mean square error increases. One of the reasons that provokes the errors is that some of the activated fuzzy rules are excluded from the fuzzy inference. It is also possible to increase the accuracy of the fuzzy system through properties of continuity. The proposed method guarantees fulfilling of the property of continuity, as the intersection point of the adjustment linguistic terms equals 0.5 when a parametrized membership function is used. The causes of errors and a way to delete them are reviewed in the paper. The proposed method excludes errors which are inherent to the traditional and non- traditional models of defuzzification. Comparative analysis of the proposed method of defuzzification with traditional and non-traditional models shows its effectiveness.  相似文献   

12.
A method of synthesis of fuzzy stabilization systems for a broad class of dynamic objects under the assumption that the mathematical model of the object is not known a priori is proposed. The control is formulated in the form of a proportional law of adjustment as a function of a macro-variable; the square of the Euclidean norm of the phase variables is adopted as the macro-variable. An analogous variable characterizes the distance of the object from the equilibrium position. Despite the simplicity of the control law, its sign remains constant due to the fact that the macro-variable is positive-definite over the entire phase space. The switching times of the signals are determined by fuzzy identification of the system’s dynamic modes on the basis of measurement of the derivatives of the macro-variable.  相似文献   

13.
Measurements of spring phenological dates in boreal regions using NDVI can be affected by snowmelt. This impacts the analysis of interannual variations in phenology and the estimates of annual carbon fluxes. For these two objectives, snowmelt effect must be removed from the phenological detection. We propose a methodology for determining the date of onset of greening in the 1982-2004 period using SPOT-VEGETATION (VGT) and NOAA Advanced Very High Resolution Radiometer (AVHRR) data. From 1998 onwards, the date of onset of greening is taken as the date at which the Normalized Difference Water Index (NDWI), calculated from SPOT-VGT near and short-wave infrared bands, starts increasing. This index decreases with snowmelt but increases with vegetation greening. For the 1982-2001 period, the date of onset of greening is the date at which AVHRR-NDVI equals a pixel specific threshold (PST), determined using the results of the NDWI method in the years common to the two datasets. The methods are validated using in situ measurements of the dates of leaf appearance. RMSE of 6.7 and 7.8 days, respectively, is found using NDWI-VGT and PST-NOAA methodologies, and the difference between the two methodologies in the common years is small. Very importantly, the dates are not biased. The interannual variations of the 23-year spring phenology dataset on the study area in northern Eurasia are analysed. In average over the study area, an advance of 8 days and a delay of 3.6 days are, respectively, found over the periods 1982-1991 and 1993-2004. These results confirm and complete previous studies about the greening trend, remove the uncertainty due to snow, and may improve carbon budget calculations.  相似文献   

14.
The laser is a joining tool which is particularly suitable for the application in microtechnology. The process variant laser transmission joining can be used both for welding thermoplastics and bonding of silicon and glass. The investigations presented in this paper cover detailed examinations of both processes. Concerning laser transmission welding of plastics it is examined how far the content of carbon black in the material influences the formation of the weld seam. It is shown that the optical depth of penetration, the weld seam width as well as the formation of the weld morphology differ with varying content of carbon black. Selective laser radiation bonding (SLB) is a novel method for joining silicon and glass based on the transmission heating of the interface of both joining partners and the thermo-chemical principles of silicon direct bonding. SLB shows advantages in reference to the thermal load of sensitive components like sensors and to the selectivity of the joining geometry. In this study the principle method of SLB and the latest advances like the integration of the thermal process control in the laser processing head will be presented. Also experimental test results of the process with constant laser power and thermal process control and the comparison of them will be shown.An erratum to this article can be found at  相似文献   

15.
16.
A new notion of joint, defined in terms of the state of motor (active or locked) and type of the elastic or rigid element, gear and/or link that follows after the motor, is introduced. Special attention is paid to the motion of the flexible links in the robotic configuration. The paper deals with the relationship between the equation of elastic line equilibrium, the “Euler–Bernoulli approach” (EBA), and equation of motion at the point of elastic line tip, the “Lumped-mass approach” (LMA). The Euler–Bernoulli equations (which have for a long time been used in the literature) should be expanded according to the requirements of the motion complexity of elastic robotic systems. The Euler–Bernoulli equation (based on the known laws of dynamics) should be supplemented with all the forces that are participating in the formation of the elasticity moment of the considered mode. This yields the difference in the structure of Euler–Bernoulli equations for each mode. The stiffness matrix is a full matrix. Mathematical model of the actuators also comprises coupling between elasticity forces. Particular integral of Daniel Bernoulli should be supplemented with the stationary character of elastic deformation of any point of the considered mode, caused by the present forces. General form of the elastic line is a direct outcome of the system motion dynamics, and cannot be described by one scalar equation but by three equations for position and three equations for orientation of every point on that elastic line. The choice of reference trajectory is analyzed. Simulation results are shown for a selected robotic example involving the simultaneous presence of elasticity of the gear and of the link (two modes), as well as the environment force dynamics.  相似文献   

17.
针对空间想象能力培养的教学需要,对基于Android 平台的工程图学助教助学系统 进行了研究。根据教与学的需要,确定了系统功能,设计了软件的框架结构。分析研究了移动设 备的系统平台,选择了系统的开发及运行平台。通过分析Android 框架中OpenGL ES 的设计接口, 实现了模型的轴测显示模式。通过分析OpenGL ES 中glDrawElements 方法的数据需求和VRML97 的数据格式,设计了虚拟模型加载器,实现了Android 系统中的VRML 模型3D 浏览器。开发了 软件的核心功能模块,设计实现了基于Android 平台的工程图学助教助学系统。该系统因其创新 性和实用性,在2014 年第十四届全国多媒体课件大赛中荣获一等奖。  相似文献   

18.
田勇    王洪光  潘新安  胡明伟   《智能系统学报》2019,14(2):217-223
针对协作机器人的构型分析研究,得出了偏置是影响机器人构型的一个重要因素。首先,对现有典型协作机器人的构型进行分析,通过构型间的内在联系与演化过程得到构型之间的差异。然后利用构型之间的差异引出了偏置的定义,并通过偏置对关节运动范围的影响将其分为S型偏置和Y型偏置。最后以全局性能指标、工作空间体积指标和灵活工作空间指标为性能评价标准,对iiwa、Sawyer、Yumi三种典型构型的性能进行了仿真。通过对比分析可知,偏置的存在使构型的全局性能和工作空间体积性能降低,但对灵活工作空间性能有提高作用。结果表明偏置是影响机器人性能的重要因素,该分析研究为协作机器人的构型设计提供了理论依据。  相似文献   

19.
An artificial touch perception system has been created in order to study a method of processing information obtainable through tactile exploration of three-dimensional forms. The results can be useful for several purposes.The first part of the work concerns the project of the tactile explorator. For this purpose we used a kind of artificial limb like a finger with a certain number of touch sensitive transducers distributed along the surface of the finger tip. The information received by touching the object with the finger, is successively utilized as the input of the control servosystem which moves the finger point-by-point along the object surface in order to proceed with the exploration. It must be noticed that, from a philosophical point-of-view, the parallel approach with more fingers touching simultaneously the object in several points, is equal to sequential touching of these points by one moving finger.The second part describes the use of the propositional calculus in logical classification of the objects, as a method of three-dimensional pattern recognition.Elaboration of the input data obtained by tactile exploration, and computation of characteristic geometrical features of three-dimensional forms, has been performed on computer.  相似文献   

20.
Abstract This paper presents some of the results of the study of seven cases of innovative pedagogical practices using ICT. The study was performed in the framework of the application of SITES M2 in Chile. The results are divided in two sections. First is a summary of each case, highlighting its innovative characteristics that serve as models of 'good practice' for Chilean teachers. Second, the results of the analysis of what teachers did are outlined; the impact on students and the type of teaching and learning activities in use. Results show that these projects did not provide evidence of having impact on students' learning as defined in the national curriculum. However, they show that students participating in these projects could learn other things, had the opportunity to develop abilities defined as cross-curricular and practised ICT related skills. The analysis of the teaching and learning activities highlights some deficiencies in the way that teachers implement new teaching strategies.  相似文献   

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