A general and formal method for the program static analysis

This paper tries to provide a general and formal method for the program static analysis. For this purpose, a projecting model of directed graph is developed. The regularity of control flow and data flow as well as programs are defined. How to analyse the programs by means of projecting is discussed. The method proposed here is called “projecting technique”, which has been successfully used in a fine automated analysis system for FORTRAN programs. It appears more general, simpler and more flexiable than those methods proposed before.     

Optimization of program recursive function calls analysis method

Static analysis can be classified into intra-procedural analysis and inter-procedural analysis-by-analysis objects. Inter-procedural analysis need to analyze the whole program adopting bottom-up parsing algorithms. Inter-procedural analysis can be converted to intra-procedural analysis by logging the context of follower’s function call in bottom-up analysis. However, the existence of recursive function calls in program increases the difficulty of inter-procedural analysis, which affects the detection accuracy of static analysis to some extent. An optimal method for analyzing the recursive function calls of program is presented in this paper. This method can lift the recursive function calls in function call graph of the program to be analyzed on the premise that vital function calls will be preserved. In this way, the false negative rate and false positive rate of program static analysis can be reduced and the accuracy of program security check can be improved.     

Logical approximation for program analysis

The abstract interpretation of programs relates the exact semantics of a programming language to a finite approximation of those semantics. In this article, we describe an approach to abstract interpretation that is based in logic and logic programming. Our approach consists of faithfully representing a transition system within logic and then manipulating this initial specification to create a logical approximation of the original specification. The objective is to derive a logical approximation that can be interpreted as a terminating forward-chaining logic program; this ensures that the approximation is finite and that, furthermore, an appropriate logic programming interpreter can implement the derived approximation. We are particularly interested in the specification of the operational semantics of programming languages in ordered logic, a technique we call substructural operational semantics (SSOS). We show that manifestly sound control flow and alias analyses can be derived as logical approximations of the substructural operational semantics of relevant languages.     

A program for the predictor-corrector numerov method

Title of program: PCNUM Catalogue number: AARJ Program ontainable from: CPC Program Library, Queen's University of Belfast, N. Ireland (see application form in this issue) Computer: IBM 370/3031; Installation: University of Windsor Computer Centre Operating system: OSMVT under VM Programming language used: FORTRAN IV High speed storage required: 10 Kwords (for 8 channels) No. of bits in a word: 32 Overlay structure: none No. of magnetic tapes required: none Other peripherals used: card reader, line printer No. of cards in combined program and test deck: 829 Card punching code: EBCDIC     

面向语句分值的C程序静态评分方法

针对现有评测方法结果过于粗糙的问题,提出面向语句分值的C程序静态评分方法.定义答案程序中语句分值的表示形式,引入程序语句依赖图准确表示待判定程序的语法结构;基于语句分值及依赖关系将程序语句依赖图划分为路径片段集合,通过匹配待判定程序和答案程序的路径片段集合相似度获得程序分值.实验结果表明,相比现有评测方法,该方法能够明...     

Improved program for multiple regression analysis

A modification is introduced into the computer program for multiple regression analysis due to Efroymson. When a variable is to be tested for either introduction into or removal from the regression equation, the relevantF level is calculated recursively for the effective degrees of freedom instead of assuming a fixed value. The test of significance is therefore carried out exactly at the level specified, no matter how many variables are introduced in the final equation.     

基于MATHEMATICA的因次分析程序

因次分析是一种重要的数学建模方法,广泛应用于化工原理中与湍流有关的物理现象的无因次数群关联式的建立。经典化工原理在因次分析过程中采用手算法进行符号运算,非常烦琐；本文基于MATHEMATICA软件强大的符号运算功能,给出了一个因次分析程序,用来进行因次分析中的这些烦琐而重复的计算。本文还给出了该程序的若干应用实例。     

Formal analysis of the Shlaer-Mellor method: Towards a toolkit of formal and informal requirements specification techniques

In this paper, we define a number of tools that we think belong to the core of any toolkit for requirements engineers. The tools are conceptual and hence, they need precise definitions that lay down as exactly as possible what their meaning and possible use is. We argue that this definition can best be achieved by a formal specification of the tool. This means that for each semi-formal requirements engineering tool we should provide a formal specification that precisely specifies its meaning. We argue that this mutually enhances the formal and semi-formal technique: it makes formal techniques more usable and, as we will argue, at the same time simplifies the diagram-based notations.At the same time, we believe that the tools of the requirements engineer should, where possible, resemble the familiar semi-formal specification techniques used in practice today. In order to achieve this, we should search existing requirements specification techniques to look for a common kernel of familiar semi-formal techniques and try to provide a formalisation for these.In this paper we illustrate this approach by a formal analysis of the Shlaer-Mellor method for object-oriented requirements specification. The formal specification language used in this analysis is LCM, a language based on dynamic logic, but similar results would have been achieved by means of another language. We analyse the techniques used in the information model, state model, process model and communication model of the Shlaer-Mellor method, identify ambiguities and redundancies, indicate how these can be eliminated and propose a formalisation of the result. We conclude with a listing of the tools extracted from the Shlaer-Mellor method that we can add to a toolkit that in addition contains LCM as formal specification technique.     

An efficient method for computing dynamic program slices

We propose an efficient method for computing dynamic slices of programs. Our method is based on construction of data dependence edges of program dependence graph at run-time. We introduce the concept of compact dynamic dependence graphs (CDDGs) of programs. We show computation of dynamic slices using CDDGs to be more efficient than existing methods.     

An improved block sequencing method for program restructuring

The execution performance of a program in a virtual memory system is highly dependent on its internal organization. There are several program tools available for reorganizing a program to improve its paging performance. This paper critically analyzes some of the methods in use and proposes a new approach that is experimentally shown to produce better results.     

A systematic method of dynamics for flexible robot manipulators

In this article, a systematic method to derive dynamic equations of motion for flexible robot manipulators is developed by using the Lagrangian assumed modes method. The proposed method can be applied to dynamic simulation and control system design for flexible robot manipulators. In the proposed method, the link deflection is described by a truncated modal expansion. The operations of only 3x3 matrices and/or 3 × 1 vectors exist in the method. All the dynamics computations are performed in the link coordinate systems, where the kinematics informations are computed with the forward recursion from the base to the hand tip and the dynamics informations are computed with the return recursion. As generally compared with other existing methods, the method proposed in this article is, computationally, more simple, systematic, and efficient. A computational simulation for a single-link flexible robot manipulator is presented to verify the proposed method. © 1992 John Wiley & Sons, Inc.     

Front solution program for transmission tower analysis

A simpler version of the frontal solution technique suitable for solving structures with large number of members is described here. The facilities of the program are brought out with regard to the re-solution and re-design of a large structural problem. It is used here to solve a transmission tower problem and the resulting stress distribution in the main members are discussed.     

Multilevel static analysis for improving program quality

In this paper, we discuss some program analysis methods for finding defects in source code that are combined to form a multilevel analysis system. The first level consists of the checks using abstract syntax tree (AST) walks and intraprocedural dataflow; this level also builds a memory model for the subsequent levels. The memory model requires evaluating integer expressions and points-to sets. The second level is an interprocedural summary-based approach whereby the program features of interest are calculated as attributes of value classes that are formed in the program. Finally, the third level is a path-sensitive analysis that builds reachability formulas for program points and tracks the predicates that should hold for the desired features to be observable. The errors are found by testing the formulas for satisfiability with an SMT solver. All these levels of analysis are implemented in the Svace analyzer toolset, which demonstrates scalability up to millions of lines of code and precision of 60–90% true positives.     

Knowledge-based program analysis

Automatic program analysis is regarded here as both the mechanized process of understanding high-level concepts from program text and the use of those concepts to guide program maintenance. A knowledge-based program analysis tool called PAT, which realizes this concept, is described. PAT uses an object-oriented framework to represent programming concepts and a heuristic-based concept-recognition mechanism to derive high-level functional concepts from the source code. As an example, a segment of a much larger program written in a Pascal-like language is analyzed using PAT     

Computer program analysis

The computer, of all recent technological developments, with its vast storage capacity, tremendous speed, ease of storage and retrieval and its flexibility of programming has perhaps made the most significant impact on the educational process and manifests itself as having the greatest potential in enhancing and enriching the teaching/learning system. Its evolution as a computing device from the Mark I computer to the advent of the ‘miracle chip’ has made it possible, and in many instances mandatory, to utilize computer technology in all levels of instruction.The purpose of this paper is to demonstrate the principle that an elementary understanding of computer programming and the development and illustration of the structure of computer program analysis will be valuable assets in the understanding and teaching of mathematics and may be used as modelling devices to simulate the stages of learning.