Abstract: This paper describes a family of tools which not only supports software development, but also assures the quality of each software product from the requirements definition to the integrated system. It is based upon an explicit definition of the design objectives and includes specification verification, design evaluation, static program analysis, dynamic program analysis, integration test auditing, and configuration management.

Abstract: A static analysis of Prolog programs was made for the purposes of revealing the behavior of Prolog programs and of getting useful information for system design. This analysis consists of two parts: one analyzes general aspects of Prolog programs, the other evaluates some compiler techniques which have a great deal of interest. This work has been done using a program written in Prolog, which collects data from test programs. This document summarizes the results of this static analysis.

Abstract: An efficient element for static and dynamic analysis of plates including geometric effects is presented. A formulation of the “heterosis element” presented by Hughes and Cohen for linear static analysis of Mindlin plates is given. This formulation is then extended to include large displacement effects using Von‐Karman assumptions and updated Lagrangian formulation. Several numerical examples for both static and dynamic loads are presented.

Abstract: A new method for the classification of power cell structures is detailed for the static analysis of power converters.

Abstract: Prolog programs are executed from left-to-right and top-to-bottom with backtracking to the most recently activated choice-point when a failure occurs. This execution strategy is based on a sequential execution model and has been implemented with modest efficiency in conventional computer systems [12,16]. In this thesis, two ways are explored to improve the performance of a Prolog system. The first way is a more intelligent form of backtracking. The second way is to exploit AND-parallel execution. Both intelligent backtracking and AND-parallel execution require information about the dependency between body literals. This information can be derived either at compile-time by using a static analysis or at run-time. Although a run-time analysis is more effective than a static (hence worst-case) analysis, it incurs a lot of overhead at run-time and is thus inefficient. Therefore, this thesis has emphasized the use of compile-time analysis to improve run-time performance. A methodology for a Static Data Dependency Analysis (SDDA) was developed. The SDDA is based on a worst-case analysis of variable bindings. To perform the SDDA, only one declaration, which describes the worst case activation, is necessary for each procedure which can be directly invoked from the top level query. This extra work can be handled quite easily by the programmer. The cost of doing the SDDA is shown to be comparable to the cost of compilation of a Prolog program. The outputs from the SDDA are a collection of data dependency graphs, one for each clause in a Prolog program. From data dependency graphs, both intelligent backtracking and AND-parallel execution can be determined. A scheme for compiling intelligent backtracking based on the SDDA has been designed. To take full advantage of dependency graphs, three different types of backtracking are differentiated. At run-time, when a subgoal fails, a backtrack literal can be determined by the type of the backtracking and its corresponding backtracking path. Execution including this intelligent backtracking is simulated for a sequential Prolog machine. It includes modifications of the hardware and the compiler. This scheme has been proved to be very effective for improving the execution of Prolog programs. A scheme to exploit AND-parallelism is also proposed. It includes generating parallel executable tasks by the SDDA, using a set of message protocols to coordinate co-operating processes, exploiting both intelligent backtracking and parallel backtracking. It is shown that Prolog has potential in parallel processing because of its procedural invocation, non-deterministic execution, concise syntax, single-assignment variable bindings, and local variable scoping.

Abstract: A finite element program for the analysis of interfaces and composite structures with microcomputer is presented. It runs on a Tektronix 4051 8-bit microcomputer with disc storage and uses block matrices in the assembly and solution processes. It can solve problems with up to about a thousand degrees of freedom and is mainly limited to two dimensional thermo-elastic static analysis. The classical laminated plate theory is used for the analysis of composite structures. For interface analysis, special elements were developed to satisfy all the continuity conditions at the interfaces. A selection of examples is presented. These examples illustrate the efficiency of the program and the accuracy of the developed interface elements, which should still be improved by implementation on more powerful microcomputers and by software extensions in progress.

Abstract: Prolog programs are executed from left-to-right and top-to-bottom with backtracking to the most recently activated choice-point when a failure occurs This execution strategy is based on a sequential execution model and has been implemented with modest efficiency in conventional computer systems 12,16 In this thesis, two ways are explored to improve the performance of a Prolog system The first way is a more intelligent form of backtracking The second way is to exploit AND-parallel execution Both intelligent backtracking and AND-parallel execution require information about the dependency between body literals This information can be derived either at compile-time by using a static analysis or at run-time Although a run-time analysis is more effective than a static (hence worst-case) analysis, it incurs a lot of overhead at run-time and is thus inefficient Therefore, this thesis has emphasized the use of compile-time analysis to improve run-time performance A methodology for a Static Data Dependency Analysis (SDDA) was developed The SDDA is based on a worst-case analysis of variable bindings To perform the SDDA, only one declaration, which describes the worst case activation, is necessary for each procedure which can be directly invoked from the top level query This extra work can be handled quite easily by the programmer The cost of doing the SDDA is shown to be comparable to the cost of compilation of a Prolog program The outputs from the SDDA are a collection of data dependency graphs, one for each clause in a Prolog program From data dependency graphs, both intelligent backtracking and AND-parallel execution can be determined A scheme for compiling intelligent backtracking based on the SDDA has been designed To take full advantage of dependency graphs, three different types of backtracking are differentiated At run-time, when a subgoal fails, a backtrack literal can be determined by the type of the backtracking and its corresponding backtracking path Execution including this intelligent backtracking is simulated for a sequential Prolog machine It includes modifications of the hardware and the compiler This scheme has been proved to be very effective for improving the execution of Prolog programs A scheme to exploit AND-parallelism is also proposed It includes generating parallel executable tasks by the SDDA, using a set of message protocols to coordinate co-operating processes, exploiting both intelligent backtracking and parallel backtracking It is shown that Prolog has potential in parallel processing because of its procedural invocation, non-deterministic execution, concise syntax, single-assignment variable bindings, and local variable scoping

Abstract: In this article the direct static equilibrium approach for stability analysis is used to study the behaviour of a perfect column made of a linear three-element model material and subjected to a concentric load. The study confirms that such a traditional static analysis admits only one non-zero eigenvalue, namely the load a the instant of application, referred to as the Euler load, PE, for the corresponding elastic column. A new interpretation of adjacent equilibrium configurations for viscoelastic structures is introduced which permits an ‘exact’ static analysis of the problem. The results from this analysis agree, in part, with those obtained from a general dynamic stability analysts. They help to clear up some misinterpretations resulting from the application of the static approach and show that time, being inherently an asymmetric parameter, generates effects typical of asymmetric influences and decreases the critical load of the structure.

Abstract: A method to improve finite element models for thermal deformation analyses has been proposed. In this method, a model is adjusted so that the results of analysis by the model fit experimental ones. The adjustment process consists of the following steps : first, a static deformation of a structure due to a unit force is obtained, based on Maxwell-Betti's reciprocal theorem, from the measured temperature distribution of the structure and the resulting thermal displacement measured at one point of the structure ; second, the experimental result thus obtained is compared with the analytical result obtained by static analysis by using the model ; third, the discrepancy between the two results is eliminated by modifying the analysis model. A case study has been done for a finite element model of an index unit of an NC lathe to show that this method is effective not only to improve the accuracy of finite element analysis but also to find out errors included in experimental data to be used in adjustment.

Abstract: : Strain gage transducers are commonly used in the formation of measurement circuits for recording different physical phenomena such as acceleration, displacement, pressure, etc. One method of rating used in these circuits is the shunt resistor calibration technique, which is considered both satisfactory and reliable. A mathematical model representing the static measurement circuit is used to study the effect of major parameters on the calibration procedure. Three parameters are considered: the length of the cable which connects the transducer to the rest of the measurement circuit elements, the nonlinear characteristic of the transducer, and the balanced potentiometer setting. The main advantage gained from this investigation is the improvment in measurement accuracy. Keywords: Army Corps of Engineers; Waterways; Experimental station; Statistical analysis; Static electrical response; and Strain gage bridge circuits. (Author)