ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677177

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The complex dynamical behaviour, including phenomena such as subharmonics, quasiperiodicity and chaos, of two single‐degree‐of‐freedom structural systems, namely the elasto‐plastic system with hysteresis and the elastic bilinear system under harmonic excitations, is investigated. The parameter‐sensitive nature of the nonlinear behaviour and its implications to our understanding of nonlinear systems are discussed.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677178

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Based on the complex potentials formulation and conformal mapping approach, we derive the fundamental solution for a point force acting in an infinite plane containing an arbitrary shaped notch. The solution satisfies the traction‐free boundary condition along the notch. Therefore, in the boundary element computation of the stress distribution for a notch problem the notch boundary can be excluded from the path of boundary integration, and the high stress gradient around the notch is not disturbed. Several examples are given to show the efficiency and accuracy resulting from the implementation of the present fundamental solution in the boundary element computation of the stress concentrations around notches and the stress intensity factors for elastic crack problems.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677179

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In this paper, the boundary integral equation (BIE) method is employed to investigate the radiation and scattering of time‐harmonic elastic waves by obstacles of arbitrary shape embedded in an infinite medium. Based on the vector BIE, entirely free of Cauchy principal value integrals, an efficient numerical scheme using quadratic isoparametric boundary elements is proposed. Furthermore, the difficulty of non‐uniquess of a solution inherent with BIE formulations for exterior elastodynamic problems is studied numerically and analytically. The counterparts of the combined Helmholtz integral formulation method for elastodynamics together with the least‐square or Lagrange‐multiplier technique are derived and applied to overcome this difficulty successfully. In addition, the elastic‐wave fields radiated or scattered by either a spherical cavity or a rigid sphere in an infinite medium are calculated and the results are compared with the analytical solutions to demonstrate the accuracy and versatility of the proposed numerical scheme.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677180

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The concept of an equivalent time constant and model expansion method are introduced for the design of a synthetic stabilization acceleration autopilot. In the autopilot control loop, an extended Kalman filter is employed to estimate the time‐varying airframe parameters. The performance of the autopilot and the extended Kalman filter is investigated through computer simulations. Two main results are found: the model expansion method can efficiently specify the gains of the autopilot control loop, and good command following characteristics of the autopilot have been obtained in the computer simulations. The results also show an acceptable estimation error for the extended Kalman filter.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677181

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The purpose of this study is the investigation of the adsorption of heavy metals from wastewater with waste activated sludge (WAS) so as to increase the operational flexibility of activated sludge processes for the shock loading problems of heavy metals. By contacting the raw wastewater with WAS, before it entered the activated sludge process unit, some heavy metals in the wastewater were removed, and the pH value of the acidic wastewater rose. Five metals, Cu, Zn, Ni, Cd and Pb, were studied, some factors which affected this biosorption phenomena were investigated, and expressions of the adsorption isotherms were discussed. A semi‐empirical mass transfer‐adsorption model was developed to describe the kinetic experimental data.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677182

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This paper presents a method for designing a diagnosable system. The nature of a (locally) diagnosable system is first studied. The theoretical result is then applied to determine the proper set of test points so that the circuit under design is perfectly diagnosable. Two examples, one for a linear system and the other for a nonlinear system, are given. Our simulation outcome shows that the desired diagnosable system may not result if the choice of test points is limited by some constraints.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677183

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The computer prediction of turbogenerator behaviour following fault or disturbance conditions has become an important feature in the assessment of machine system design, pre‐commissioning test appraisals, system operational procedures, machine monitoring strategy and post‐event damage diagnoses. In this paper computer methods are described to assess the comparative severity of various electrical faults and disturbances, the effect of specific operational practices together with the prediction of peak torsional transient behaviour. This paper is supported by realistic examples simulating the transient behaviour of a number of generational units.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677184

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The layer assignment problem for VLSI routing is the problem of determining which layers can be used for routing the wire segments in the interconnections of nets so that the number of vias is minimized. In this paper, we transform the problem of layer assignment for three‐layer routing to the contractability problem of 3‐colorable graph. This problem is shown to be NP‐complete and a heuristic algorithm is proposed on the basis of the graph contractability model. From our experimental results, the algorithm is faster and efficient to generate very good results. In the average, the number of vias can be reduced by 30 percent or so.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677185

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Recent research in knowledge‐based expert systems of VLSI design tools has concentrated on placement, routing, and cell generation. This paper presents an alternative application for artificial intelligence (AI) techniques on compaction design for a VLSI mask layout‐expert compactor. In order to overcome the shortcomings of iterative search through a large problem space within a working memory, and therefore, to speed‐up the runtime of compaction, a set of rule‐based region query operations and knowledge‐based techniques for the plane sweep method are proposed in this system. Experimental results have explored the possibility of using expert system technology (EST) to automate the compaction process by “reasoning” out the layout design and applying sophisticated expert rules to its knowledge base.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677186

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor