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1.
An increasingly dynamic environment and the ongoing trend towards customized products are heightening the requirements which companies have to meet, leading to constantly changing structures and processes. As a result, successful production management and the transformability which an enterprise and its order management system has to display are closely connected. The present article describes an order management system for transformable manufacturing enterprises based on systems theory and management cybernetics.  相似文献   

2.
Effective lamina and laminate constitutive relations based on the Aboudi micromechanics theory were presented in Part I of this paper. In this part the laminate constitutive relations are incorporated into a first-order shear deformation plate theory. The resulting boundary value problem is solved by utilizing the finite element method. Computational aspects of the numerical solution, such as the temporal integration of the inelastic strains and the spatial integration of bending moments are also addressed. Numerical results of the nonlinear response of metal matrix composites subjected to extensional and bending loads are presented. Experimental data from available literature are in good agreement with the numerical results.  相似文献   

3.
The nonlinear behavior of continuous-fiber-reinforced metal-matrix composite structures is examined using a micromechanical constitutive theory. Effective lamina constitutive relations based on the Aboudi micromechanics theory are presented. The inelastic matrix behavior is modeled by the unified viscoplasticity theory of Bodner and Partom. Debonding between fiber and matrix phases is also considered. In Part II of this paper, the laminate constitutive relations are incorporated into a first-order shear deformation plate theory. The resulting boundary value problem is solved by the finite element method.  相似文献   

4.
Mikkonen  T. Pruuden  P. 《Computer》2001,34(11):52-56
Ambiguous requirements and those that emerge late in the design cycle often complicate development and throw off established schedules. The authors describe how reformulating information missing at the design stage into a flexibility requirement can turn the absent data into a design driver. Designers constantly run into issues that have yet to be understood through specification, system design, or standardization. Changes in evolving technologies and businesses often result in unstable system requirements. Reliable hardware or mechanical details might not be available until very late in the development process. Yet engineers must initiate software development even though some subsystem details have not yet been completely defined. Missing information and related flexibility requirements can lead to a design plagued by many well-known problems that affect performance, modularity, scalability, and clear separation of concerns. In some cases, developers must sacrifice rules of thumb to maintain planned development schedules. Providing flexibility for everything in the system isn't possible, so developers will always need to determine the static requirements and explicitly state where continued development and rapid modification require flexibility  相似文献   

5.
EDIT is a time-sharing system which offers interactive services over the NPL network. These services include various kinds of editing, word processing, data movement and file control. The system is implemented on a PDP11/40 and can serve up to 30 users simultaneously, on high-speed displays and other terminals. There is an attached background processor (PDP11/45) which supports graphics and background jobs. This paper describes the design and implementation of EDIT and relates this to the needs of the system and of its users.  相似文献   

6.
This paper presents the SYMBAD (similarity based agents for design) system, exploring multi-agent aspects in an architecture company, capturing, cataloging, and communicating information produced by the team members. The main task managed by the designers is to build stands to present the image of a company, project its presence in the market and emphasize the corporate identity to all prospects. From conceptual design to the construction of a final product, a stand project passes through many hands, each one adding bits and pieces until it is completed. Reuse of materials and ideas is less feasible as design complexity increases. The processes and problems in stand projects are quite common and can be easily found in other design situations. We present an agent framework to improve process awareness in an architecture company. The agents instrument the process to produce global awareness, to facilitate reuse and optimize the process as a whole. In this paper we present the agent architecture, as well as each agent’s general functioning and reasoning rules.  相似文献   

7.
The growth and some characteristics of information technology (IT) are outlined, and the importance of ergonomics in the design of IT systems is illustrated. Some immediate questions for the next 7 years are discussed, including research gaps and needs, the development of design procedures, a suggested ergonomics framework and some industrial design aspects. Longer-term questions discussed are the passing of paper, the reduction of writing, the victory of voice and the wired society. Finally, some of the important broader issues are mentioned and the need for collaborative synergy by ergonomists, computer professionals, architects and industrial designers is emphasized.  相似文献   

8.
Serpentine robots are slender, multi‐segmented vehicles designed to provide greater mobility than conventional mobile robots. Serpentine robots are ideally suited for urban search and rescue, military intelligence gathering, and inspection tasks in hazardous or inaccessible environments. One such serpentine robot, developed at the University of Michigan, is the “OmniTread OT‐4.” The OT‐4 comprises seven segments, which are linked to each other by six joints. The OT‐4 can climb over obstacles that are much higher than the robot itself, propel itself inside pipes of different diameters, and traverse difficult terrain, such as rocks or the rubble of a collapsed structure. The foremost and unique design characteristic of the OT‐4 is the use of pneumatic bellows to actuate the joints. The pneumatic bellows allow the simultaneous control of position and stiffness for each joint. Controllable stiffness is important in serpentine robots, which require stiff joints to cross gaps and compliant joints to conform to rough terrain for effective propulsion. Another unique feature of the OmniTread design is the coverage of all four sides of each segment with drive tracks. This design makes the robot indifferent to rollovers, which are bound to happen when the slender bodies of serpentine robots travel over rugged terrain. This paper describes the OmniTread concept and some of its technical features in some detail. In the Experiment Results Section, photographs of successful obstacle traverses illustrate the abilities of the OT‐4. © 2007 Wiley Periodicals, Inc.  相似文献   

9.
This paper presents the computer-aided optimal design of a template digitizer-NC contouring system which utilizes a set of polar coordinates. The system can operate both as a copying machine or as a numerical control (NC) machine. Part I of the paper describes the proposed system and its salient features. It also analyzes the contouring error due to the incremental approximation of the contour. This error is dependent on the relative location of the contour pole from the machine pole. An objective function relating the area error to the position of the contour is derived and an optimization procedure to minimize this error is outlined. Test results of an attempt to locate the poles of three test contours for minimum error are then presented.  相似文献   

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The heuristic clustering methods based on similarity coefficient are considered to be very efficient for providing modularity and flexibility in a cellular manufacturing systems (CMS's). Various algorithms have been implemented in these heuristic methods. However, these algorithms suffer from string effect which is also known as “chaining”. Sedveral studies have reported this problem, yet not much research has been conducted to investigate its impact on actual clustering process.

This paper presents results from an analytical study performed to determine the severity of chaining problem and other characteristics associated with the clustering process of four selected algorithms. The four algorithms are Single linkage clustering (SLINK), Average linkage clustering (ALINK), Weighted average linkage clustering (WLINK), and Complete linkage clustering (CLINK). A sample of fifty problems with randomly generated data sets was used to determine feasible solutions consisting of machine cells and corresponding part families from each of the four algorithms. A quantitative measure is proposed for evaluating the performance of different algorithms. The study concludes that the chaining effect for CLINK, WLINK, ALINK and SLINK progresively worsens from CLINK to SLINK in the same order. The study also provides important guidelines to designers of a CMS in selecting the most efficient algorithm for a given problem data. Several important statistical results are also presented.  相似文献   


12.
Due to the growing complexity and size of software systems, the development of correct and easy to maintain software has become more and more of a problem. This is especially true for distributed systems with real-time requirements. Therefore, great efforts have been made to overcome this problem. However, most approaches either do not consider every aspect of interest or are restricted to only one development phase. This paper describes OASIS, an open environment, that allows the integration of different analysis techniques in different system development phases, and presents the existing OASIS-toolset, that is already incorporated in this environment.  相似文献   

13.
There is a great deal of literature dealing with the use of the computer in designing acceptance sampling plans. The general approach is to use some approximation technique to generate minimum sample size plans whose OC curves will approximate the desired Producer's Risk and Consumer's Risk levels. Since only rarely will a single such approximation satisfy both (1-) and β requirements some means, either averaging or selection, is used to select a plan. Plans so determined are acceptable but often not optimal, and planes with significantly smaller sample size may exist which are very close to optimal.

This paper reports the development and use of a computer program which may be used to design single sampling plans using either the binomial or Poisson distribution. The program also finds alternate plans with smaller sample size, and gives a measure of the proximity of such alternate plan to optimality. Some rudimentary artificial intelligence techniques are employed in the search and selection of optimal plans and the near-optimal alternative plans.

An extended version of the program also supports experimentation with a variety of criteria of optimality for the selection of candidate plans from those generated.

The main program is written for use under MS/PC-DOS in both Turbo Pascal and Turbo C. The extended version uses only Pascal.  相似文献   


14.
In many cases precise probabilistic data are not available on uncertainty in loads, but the magnitude of the uncertainty can be bound. This paper proposes a design approach for structural optimization with uncertain but bounded loads. The problem of identifying critical loads is formulated mathematically as an optimization problem in itself (called anti-optimization), so that the design problem is formulated as a two-level optimization. For linear structural analysis it is shown that the antioptimization part is limited to consideration of the vertices of the load-uncertainty domain. An example of a ten-bar truss is used to demonstrate that we cannot replace the anti-optimization process by considering the largest possible loads.  相似文献   

15.
SR is a new language for programming software containing many processes that execute in parallel. The language allows an entire software system that controls a potentially large collection of processors to be programmed as an integrated set of software modules. The key language mechanisms are resources, operations and input statements. The language supports separate compilation, type abstraction, and dynamic communication links; it also contains novel treatments of arrays and procedures. This paper gives an overview of the language mechanisms, discusses some of the major design decisions and describes one implementation.  相似文献   

16.
Long-term observed and relative survival are important outcome measures of cancer patient care reported routinely by many cancer registries, but no commercial statistical software exists for estimating relative survival or performing period survival analysis. The programs publicly available focus only on certain methods, require specific input data formats and often are macros or functions which require underlying software packages. Here we introduce SURVSOFT, a comprehensive, user-friendly Windows program with graphical user interface. It can handle different input data formats and incorporates a variety of nonparametric statistical methods for survival data analysis. SURVSOFT produces high-resolution graphs, which can be printed, saved or exported to be used with standard graphics editors. The use of SURVSOFT is illustrated by the analysis of survival data from the Bavarian Cancer Registry.  相似文献   

17.
A normal synchronous time multiplexed system has low capacity utilisation of a trunk channel, owing to the ON-OFF nature of speech in human conversation. A time assignment speech interpolation (TASI) system nearly doubles this efficiency, at relatively small increase in hardware cost. In TASI, during the silent period of speech, the channel is allotted to some other ‘active’ subscriber on a first-come-first-serve basis. A microprocessor based system offers a very cost effective solution from hardware count. Intel 8085 A has been selected for the purpose. The microprocessor functions in a distributed processing mode together with the main CPU controlling the stored program exchange. The system uses digital dynamic speech detectors for detecting transitions in speech over a channel, as they show considerably superior performance over amplitude detectors. An assembly language program for the system has been developed.  相似文献   

18.
This work illustrates simulation approach for optimizing the parametric design and performance of a 2-DOF R–R planar manipulator. Using dynamic and kinematic models of a manipulator different performance measures for the manipulator are obtained for different combination of parameters with effect of noise incorporated to imitate the real time performance of the manipulator. A novel approach has been proposed to model, the otherwise difficult to model, noise effects. The data generated during simulation for various parameter combinations are utilized to analyze the statistical significance of kinematic and dynamic parameters on performance of manipulator using ANOVA technique. The parameter combinations, which give optimum performance measures obtained for different points in workspace, are compared and reported.  相似文献   

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