用AutoCAD获取仿真系统的三维模型

本文通过阐述ＶｉｓｕａｌＣ＋＋读取ＡｕｔｏＣＡＤ图形系统三维图形文件ＤＸＦ的原理和方法，说明了利用ＡｕｔｏＣＡＤ实体造型功能拓展Ｃ＋＋语言的三维建模能力，是一种在计算机仿真系统中值得推广应用且简便易行的方法。     

SDAI的C++联编及其基于VERSANT的实现

ＳＤＡＩ是ＳＴＥＰ的标准数据访问接口,Ｃ＋＋作为一种面向对象语言,可以全面包容ＳＴＥＰ信息建模语言ＥＸＰＲＥＳＳ的语义功能,本文论述了ＳＤＡＩ的Ｃ＋＋早,晚联编的有关概念,从ＳＤＡＩ的原始数据类型／实体数据类型／聚集数据类型的Ｃ＋＋联编,父／子类关系等方面对Ｃ＋＋晚联编展开讨论,并介绍基于面向对象数据库ＶＥＲＡＮＴ进行ＳＤＡＩ／Ｃ＋＋联编实现的工作。     

AutoCAD获取仿真系统的三维模型

本文通过阐述Ｖｉｓｕａｌ Ｃ＋ ＋ 读取ＡｕｔｏＣＡＤ图形系统三维图形文件ＤＸＦ的原理和方法,说明了利用ＡｕｔｏＣＡＤ实体造型功能拓展Ｃ＋ ＋ 语言的三维建模能力,是一种在计算机仿真系统中值得推广应用且简便易行的方法。     

在VC^＋＋中应用DAO实现数据库管理

文章首先简要介绍了ＤＡＯ的有关知识,然后通过例程对ＶＣ＾＋＋中利用ＤＡＯ类管理数据库的方法进行了描述,最后将ＤＡＯ与ＯＤＢＣ进行了比较 。     

电气成套装置3维设计系统的研究及实现

本文以ＡｕｔｏＣＡＤＲ１２／Ｗｉｎ为平台，以ＢｏｒｌａｎｄＣ＋＋４．０为工具，完成了电气成套装置３维设计系统ＥＬＥ３ＤＣＡＤ。它利用ＡｕｔｏＣＡＤＳＱＬ的程序接口ＡＳＩ，把Ｆｏｘｐｒｏ／Ｗｉｎ编制成的外部数据库与ＡｕｔｏＣＡＤ的图形数据库联系起来。ＥＬＥ３ＤＣＡＤ基于ＡｕｔｏＣＡＤＡＭＥ，是一种实体造型的３维设计系统。该系统可得到任意角度的视图和任意多个剖切平面下的剖视图，可对电气元件进行空间碰撞检测和电气碰撞检则。     

矩阵代数Riccati方程的进一步研究

研究矩阵代数Ｒｉｃｃａｔｉ方程ＰＡ＋Ａ‘Ｐ＋Ｃ’ＰＣ－（ＰＢ＋Ｃ‘ＰＤ）（Ｒ＋Ｄ’ＰＤ）＋Ｑ＝０,所得结果改进了文献（７）的结论。     

用ARX开发明细表自动生成系统

讨论了在ＶｉｓｕａｌＣ＋ ＋ 环境下,用ＡＲＸ（ＡｕｔｏＣＡＤＲｕｎｔｉｍｅ ｅＸｔｅｎｓｉｏｎ）开发运行在ＡｕｔｏＣＡＤＲ１４ 环境下的明细表自动生成系统。     

基于VC＋＋类库的CAD／CAP集成系统的研究与实践

文章采用特征拼装及特征单元的参数化设计方法,在以Ｖｉｓｕａｌ Ｃ＋＋类库（Ｍｉｃｒｏｓｏｆｔ Ｆｏｕｎｄａｔｉｏｎ Ｃｌａｓｓ ＭＦＣ类）为数据存储、交换与管理的基础上,成功地实现了ＣＡＤ／ＣＡＰＰ集成数据的传递与共享。通过ＤＸＦ接口方式与Ｖｉｓｕａｌ Ｃ＋＋的连接,可在ＡｕｔｏＣＡＤ１４下自动生成零件图,在集成环境下自动生工艺文件。     

ODBC在数据库集中的应用研究

描述了ＯＤＢＣ技术以及如何使用ＶＣ＋＋的Ａｐｐｗｉｚａｒｄ和Ｃｌａｓｓｗｉｚａｒｄ工具编写ＯＤＢＣ应用程序。     

Windows下西文AutoCAD12.0汉化浮动菜单的ads编程实现

本文利用Ｗｉｎｄｏｗｓ下的动态数据交换（ＤＤＥ）特性，对在西文Ａｕｔｏ－ＣＡＤ１２．０的工作平台上开发汉化浮动菜单进行了研究，并在Ｂｏｒｌａｎｄｃ＋＋的环境中用ａｄｓ语言编程实现了一个ＤＤＥ程序，在ＡｕｔｏＣＡＤ的工作平台上生成良好的汉化浮动菜单框     

A method of defuzzification based on the approach of areas' ratio

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.     

An approach to the synthesis of fuzzy stabilization systems with a priori unknown model of an object

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.     

Complement of Source Equation of Elastic Line

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.     

3 Laser transmission joining in microtechnology

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     

Remote sensing of spring phenology in boreal regions: A free of snow-effect method using NOAA-AVHRR and SPOT-VGT data (1982-2004)

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.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).     

Spark平台下聚类算法的性能比较

通过实验,从运行时间、加速比、可扩展性和规模增长性4个方面比较了 Spark平台中3种典型的聚类算法即K-means聚类算法、二分K-means聚类算法和高斯混合聚类算法 的性能。实验结果表明:1)随着节点个数的增加,3种算法对百兆以上规模数据集聚类的运行时间明显减少;2)当数据集规模大于500MB时,3种算法的加速比均有明显提高,且随着节点个数的增加,加速比近似于线性增长;3)3种算法的可扩展性随着节点个数的增加而降低,当数据集规模大于500MB时,相对于K-means和高斯混合算法,二分K-means算法的可扩展性最差;4)当数据集规模大于100MB时,高斯混合算法的规模增长性远高于K-means和二分K-means算法。     

协作机器人的构型分析研究

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。     

Overview of ATM networks: functions and procedures

The purpose of this paper is to present an overview of the ATM technique. The basic principles of the ATM transfer technique, the B-ISDN layered protocol reference model, as well as the architecture and the main functions of the ATM network, are described in this tutorial. In particular, we present the main characteristics of the ATM technique, the structure of the ATM cell, the functions which deal with the protection from errored cells (HEC procedure) and the identification of the boundaries of the ATM cells (cell delineation and scrambling). The VP/VC concept is explained in detail, and the main principles and functions of the three lowest layers (Physical, ATM and Adaptation) of the B-ISDN layered protocol reference model are surveyed. The issue of Quality of Service parameters in ATM networks is reviewed, and the problem of the allocation of the network resources in response to user demands, as well as the problems of congestion control, Usage Parameter Control (UPC) and traffic modelling in ATM networks, are assessed. Finally, we present ‘possible’ sets of traffic characterization parameters, and show how possible B-ISDN sources can be modelled according to the basic on-off ATM traffic source model.