Open architecture modeling systems

CAD/CAM systems are well-organized, structured, integrated, and comprehensive tool sets for all necessary design functions. However, it is impossible to develop a CAD/CAM system that fits exactly to all possible tasks at all industrial companies even in a relatively narrow area of application. CAD/CAM systems are customized to extend their standard capabilities to meet special customer needs for their applications. Open architecture features 

Customization is considered a part of the installation such that modeling systems without some customization features cannot cope with the demands of present industrial practice. A customization toolkit is considered to be an essential structural unit of industrial modeling systems. 

These steps determine the information content of model entities. Model representation must serve the objectives and desired applications of the information stored in models. 

The boundary of a shape is composed of surfaces, as well as curves as intersections of surfaces. Complex shapes consist of a large number of curves and surfaces. Both the outside and inside boundaries can be defined on mechanical parts. The following are fundamental goals of the boundary type of shape representations. 

The boundary representation must allow all necessary geometric operations during construction, modification, and application of the model such as intersection by curves and surfaces, and modification of continuity conditions. 

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Cassel, Lillian N., and Richard H. Austing. Computer Networks and Open Systems An Application Development Perspective. Sudbury, Mass. Jones Bartlett Learning, 2000. This textbook describes the OSI architecture model. 

One of the first standards for computer communications was proposed and developed by the International Standards Organization (ISO) in the early 1980s. This network architecture model, the open systems interconnection (OSI) reference model shown in Fig. 1, describes a network through seven layers. On any of these layers, one or more protocols can implement the functions specified for the layer. Some protocol specifications based on this... 

This section presents the main characteristics of a mobile robotic system simulator. It is implemented from the kinematic and dynamic models of the mechanieal drive systems of the robotic axles to simulate different control techniques in the field of mobile robotics, allowing researchers to deepen the concepts of navigation systems, trajectory planning, and embedded control systems. This simulator, designed in a modular and open architecture, allows persons to directly apply concepts... 

New pocket portals, using WAP or Blue Tooth technology, is also becoming an attractive option. However, a cautionary note needs to be registered with the heightened importance of system security and the risks of transmitting data over open systems. Biometrics and encryption are potential solutions. Also, audit trails need to be consistent across the range of software models adopted, especially client-server architectures and hand-held IPCs. 

The two basic flowsheet software architectures are sequential modular and equation-based. In sequential modular, we write each unit model so that it calculates output(s), given feed(s), and unit parameters. This is the most commonly used flowsheeting architecture at present, and examples include Aspen+ plus Hysys (AspenTech), ChemCAD, and PROll (SimSci). In equation-based (or open-system) architectures, all equations are written describing material and energy balances as algebraic equations in the form/(x) = 0. This is the preferred architecture for new simulators and optimization, and examples include Speedup (AspenTech) and gPROMS (PSE pic). Each is discussed in turn. 

The shape and size of a molecule of a substance, together with the strength and polarity of its bonds, largely determine the properties of that substance. Some of the most dramatic examples of the important roles of molecular architecture are seen in biochemical reactions. For example, the chapter-opening photograph shows a molecular model of diazepam, better known as Valium. In the body, this relatively simple molecule enters into an extraordinary array of biochemical interactions. Valium works by binding to certain important sites in the central nervous system. Its... 

THE EVENT-TRIGGERED (ET) model of computation is presented as a generalization of the time-triggered (TT) approach. It supports hard real-time and flexible soft real-time services. The ET model is built upon a number of key notions temporal firewalls, controlled objects, temporarily valid state data, and unidirectional communications between isolated subsystems. It uses the producer/consumer rather than client/server model of interaction. In addition to describing a systems model and computation model, this article considers issues of schedu-labiUty and fault tolerance. The ET model is not radically different from the TT approach (as in many systems most events will originate from clocks) but it does provide a more appropriate architecture for open adaptive applications. 

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