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Network performance engineering can verify the design and dimensioning of large-scale control networks like CSMA-based building automation networks. It combines performance analysis with diagnosis methods to evaluate the network utilization and to detect design errors before installation and can therewith save the expenses of overdimensioning and redesign. This paper will develop a diagnosis model based on fault trees that is able to use the huge amount of performance analysis results to identify design errors and analyze their coherences. This enables not only a fast tracing back of fault causes and the derivation of solutions; it can also visualize the fault coherence to the user and help him to understand his design. Additional consulting tools implement best practice strategies, to support the user in parameterization.  相似文献   
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Large technical systems need to be designed both reliable and efficient. Specialized design tools offer therefore a simplified, abstract design and extend details autonomously in the background. Analytic and simulation based models could improve the quality by testing and dimensioning the design before implementation, but setting up the necessary models is time-consuming and expensive. Therefore many developers ask for analysis tools which are able to create their models from the available information in the design tools. This paper presents such an automated modeling approach basing on an existing design database at the example of a network analysis for building automation fieldbuses. The process of automated modeling is unfolded, and the potentials and limitations are discussed.  相似文献   
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On application of (+)-methamphetamine (1) to the albumen of embryonated hen's eggs it is possible to detect phase I as well as phase II metabolites of 1 in the allantois liquid. When application is effected on the first day of incubation, methamphetamine is less toxic than when effected on the sixth day of incubation. Besides unchanged 1 ten metabolites have been identified. Principal pathways of biotransformation are N-dealkylation as well as aromatic p-hydroxylation and--as phase II reactions--N-acetylation and other conjugation reactions. The total amount of the metabolites produced depends on time of incubation and is up to about 25% of the applied dose. Differences from, but also similarities to human metabolism have been noticed. Consequently, the experiment is likely to be suitable as an alternative method for testing biotransformation reactions.  相似文献   
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BACKGROUND AND AIMS: Outcome refers to the different facets of consequences resulting from an event or intervention. These consequences may be relevant for an individual patient, but also for society. There is a growing recognition that clinical research needs to define and focus on the outcomes of medical care. Outcome research should help health care professionals to better evaluate the effectiveness of specific interventions or a therapeutic concept. This broader base of evidence should then benefit the patients. METHODS: The literature was reviewed with respect to concepts of outcome research as well as results of outcome research after major trauma. RESULTS: Measuring outcome might be relevant for research purposes as well as in daily surgical practice. In the past, clinical research in trauma care has tended to focus on survival. Mortality rates are not out, complication rates are not out, but their value is limited and restricted to given scenarios with high mortality rates. New outcomes have to be added: such a functional status, emotional health, social interaction, cognitive function, degree of disability and other indicators of health. CONCLUSION: Despite differences in injury pattern and severity of injury, there is strong evidence from the literature that the quality of life is significantly impaired after major trauma. This is true for functional outcome as well as for psycho-social outcome in up to 70% of patients.  相似文献   
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Hollow shape component approaches, applied to shafts and similar workpieces, represent a major potential for ground-breaking innovations in lightweight engineering and safety designs. Among suitable forming technologies, spin extrusion is a pioneering and particularly flexible hollow-shaping technique. All outside form elements, straight or stepped cylinders, cones or spherical rotation elements emerge just from the kinematics of tools. The inside hollow shapes, as e.g. circular cross-sections, shaft to collar connections such as spherical triangles, polygons, splines or dovetail forms are manufactured with a shaping mandrel. Spin extrusion can be applied first and foremost at dimensions that are unattainable with other techniques. The application includes hollow shafts, thick-walled cups and semi-finished tubular products that are not to be found in off-the-shelf cross-sections. In these cases the possibility for using of massive bars is connected with very high price advantages. Furthermore material-saving machining is attracting special attention for high-grade materials.The paper characterizes substantial steps of process analysis and the appliance of a new, derived from the bound method, numerical simulation method for spin extrusion process. Holistic process analysis is the prime factor for process capability. The specific application of the developed special methods of simulation, the accumulation of process data and the integrating into the Computer numerical control of spin extrusion machine is a precondition guaranteeing high-quality assurance.  相似文献   
7.
Mechatronic Systems for Machine Tools   总被引:3,自引:0,他引:3  
This paper reviews current developments in mechatronic systems for metal cutting and forming machine tools. The integration of mechatronic modules to the machine tool and their interaction with manufacturing processes are presented. Sample mechatronic components for precision positioning and compensation of static, dynamic and thermal errors are presented as examples. The effect of modular integration of mechatronic system on the reconfigurability and reliability of the machine tools is discussed along with intervention strategies during machine tool operation. The performance and functionality aspects are discussed through active and passive intervention methods. A special emphasis was placed on active and passive damping of vibrations through piezo, magnetic and electro-hydraulic actuators. The modular integration of mechatronic components to the machine tool structure, electronic unit and CNC software system is presented. The paper concludes with the current research challenges required to expand the application of mechatronics in machine tools and manufacturing systems.  相似文献   
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