可视化解耦近场波动有限元分析系统的初步实现

解耦近场波动数值模拟技术以其能够真实反映无限域中地震动的传播特性,而逐渐成为地震工程界和岩土工程界的重要分析方法之一.但现有程序建模难度大,主程序的功能相对简单,计算结果的展示缓慢且复杂,使其在科研工作和实际工程中的应用受到了很大的限制.因此,基于VB6.0设计图形用户界面及混合编程技术,提出了一套合理利用现有软件及Fortran程序的优点来实现可视化系统开发的思路和方法,即前处理采用VB外壳函数调用Fortran程序、准备批处理文件后调用ANSYS 8.0程序等方法,实现简单及不规则复杂模型的构建;扩展Fortran主程序具有动态数组存释、多作用耦合场、左右不等高处理、自中断后重起计算等功能;后处理采用VB语言实现二维图形定制、通过ActiveX自动化协议与Surfer8.0无缝结合实现三维立体渲染图.经实例验证,该系统功能较强、界面友好,方便快捷.这为整合不同开发平台的程序以开发新的软件、为波动有限元进一步应用于工程实践提供了一条技术途径.     

A graph mining approach for detecting unknown malwares

Nowadays malware is one of the serious problems in the modern societies. Although the signature based malicious code detection is the standard technique in all commercial antivirus softwares, it can only achieve detection once the virus has already caused damage and it is registered. Therefore, it fails to detect new malwares (unknown malwares). Since most of malwares have similar behavior, a behavior based method can detect unknown malwares. The behavior of a program can be represented by a set of called API's (application programming interface). Therefore, a classifier can be employed to construct a learning model with a set of programs' API calls. Finally, an intelligent malware detection system is developed to detect unknown malwares automatically. On the other hand, we have an appealing representation model to visualize the executable files structure which is control flow graph (CFG). This model represents another semantic aspect of programs. This paper presents a robust semantic based method to detect unknown malwares based on combination of a visualize model (CFG) and called API's. The main contribution of this paper is extracting CFG from programs and combining it with extracted API calls to have more information about executable files. This new representation model is called API-CFG. In addition, to have fast learning and classification process, the control flow graphs are converted to a set of feature vectors by a nice trick. Our approach is capable of classifying unseen benign and malicious code with high accuracy. The results show a statistically significant improvement over n-grams based detection method.     

Rewriting executable files to measure program behavior

Inserting instrumentation code in a program is an effective technique for detecting, recording, and measuring many aspects of a program's performance. Instrumentation code can be added at any stage of the compilation process by specially-modified system tools such as a compiler or linker or by new tools from a measurement system. For several reasons, adding instrumentation code after the compilation process—by rewriting the executable file—presents fewer complications and leads to more complete measurements. This paper describes the difficulties in adding code to executable files that arose in developing the profiling and tracing tools qp and qpt. The techniques used by these tools to instrument programs on MIPS and SPARC processors are applicable in other instrumentation systems running on many processors and operating systems. In addition, many difficulties could have been avoided with minor changes to compilers and executable file formats. These changes would simplify this approach to measuring program performance and make it more generally useful.     

A unix tool for managing reusable software components

Sloth is a simple Unix-based tool for creating and maintaining large C programs built from reusable ‘modules’. Sloth is a collection of UNIX shell commands for creating and editing modules, and for producing executables by linking compiled code from the modules comprising a program. Sloth in a sense extends C by providing module facilities similar to those built in to newer languages such as Modula-II. The Sloth ‘extensions’, however, are at the shell level only. No changes are required in C itself; in fact, the Sloth commands invoke the standard Unix C compiler. A Sloth module contains a set of C procedures and local declarations, a set of global definitions and variable declarations, an initialization routine and an ‘import’ list of other modules containing declarations referred to, but not defined by, the module in question. The Sloth link command has one argument, the name of a ‘root’ directory. The link command automatically identifies all those modules imported directly or indirectly by the root module, checks that the object code for each module is up-to-date and recompiles where necessary. It then creates a main program in which the various initialization routines are executed in the correct order (most primitive first), compiles it and links it with all the object files and produces an executable program. Individual modules can be compiled without any knowledge of the application that uses, directly or indirectly, the module in question. Two applications that both use a collection of modules can therefore share the object code for these modules. The use and implementation of Sloth are presented, as are the experience in using it, programming techniques developed to take full advantage of its facilities, as well as several extensions, either completed or planned.     

Two-level grammar as an implementable metalanguage for axiomatic semantics

Two-level grammars can define the syntax and the operational semantics of programming languages and these definitions are directly executable by interpretation. In this paper it is shown that axiomatic semantics can also be defined using a two-level grammar with the result being a partially automatic program verification system accomplished within the framework of a language definition. These results imply that a programming language can be defined operationally and axiomatically together in complementary definitions as advocated by Hoare and Lauer. Because two-level grammars are executable, these complementary definitions accomplish a system for interpreting and verifying programs.     

C program verification in SPECTRUM multilanguage system

An extendable multilanguage analysis and verification system SPECTRUM is presented; this system is being developed in the framework of the project SPECTRUM. The prospects of the application of this system are demonstrated, as exemplified by the verification of C programs. The project SPECTRUM is aimed at the creation of a new integrated approach to the verification of imperative programs that makes it possible to integrate, unify, and combine methods and approaches for verification of imperative programs and accumulate and apply information about these programs. The specific feature of this approach is the application of a specialized executable specification language Atoment for the development of program verification tools; this language makes it possible to represent methods and approaches for verification and data for them (program models, annotations, logical formulae) in a unified format. The C component of the SPECTRUM system uses a two-level C program verification method. This method is a good illustration of the integrated approach, since it provides complex verification of C programs based on a combination of the operational, axiomatic, and transformational approaches.     

基于范畴计算的多目标语言程序生成架构

提出了一种基于范畴论的多目标语言程序生成架构,程序元素的元类型在程序元模型范畴中定义,常用的软件开发模式由元模型实例组成并带有可配置的参数,模式到可执行语言的表达式、函数、类型等映射由范畴函子统一定义。在实际应用开发时,通过函子计算将抽象模式精化到不同的目标语言程序范畴。各种语言的精化计算方式具有统一的契约规范,从而支持高度的灵活性和重用度水平。     

一个面向对象软件自动测试框架的设计和实现

介绍了一个测试用例驱动的面向对象软件自动化测试框架(简称为TCDA).TCDA使用UML作为形式化的分析和设计规格说明,从UML的体系结构视图中自动获取测试用例,并以XML的形式保存这些测试用例.TCDA可以根据具体编程语言,将测试用例翻译成由一系列源文件组成的测试脚本.测试执行过程中,测试脚本首先会被编译和链接,生成可执行文件,接着这些可执行文件将被运行,同时测试结果将被记录和分析,并最终生成一个结果分析报告.TCDA的原型系统使用Java实现.该系统包括测试配置、测试用例生成、测试脚本生成、测试执行和结果分析五个模块,分别支持以上描述的过程.     

F@BOOL@: Experiment with a simple verifying compiler based on SAT-solvers

A verifying compiler is computer system program that translates programs written by a human from a high-level language to equivalent executable programs and proves (verifies) mathematical statements specified by a human concerning the properties of the translated programs. The objective of the project F@BOOL@ is to develop a user friendly, compact, and portable verifying compiler of annotated computational programs that uses efficient and reliable automatic SAT solvers as the tools for automatic validation of correctness conditions (instead of semiautomatic proof techniques). In the period from 2006 to 2009, the SAT solver zChaff was used in the project F@BOOL@. The first experiments on the verification of simple Mini-NIL programs were performed using this solver, namely, the programs swapping variable values, checking whether three integer numbers are the sides of an equilateral or an isoscales triangle, and searching for one fake coin among 15 coins using scales. This paper considers the main ideas of the project F@BOOL@ and gives the details of the experiment on the verification of the program solving the coin puzzle.     

利用资源文件实现对软件的保护

软件加密是对软件进行保护的一种重要手段,而破解加密的技术也是日新月异,用另外一种思路对软件进行保护,重点介绍了利用资源文件对软件进行保护的思路和具体实现方法,重点阐述了利用外壳程序隐藏主程序的思路,以及资源文件的使用、基于Windows的消息应用和在C++ Builder环境下隐藏程序的方法。该方法若同软件加密等方法一起使用,会使破解软件的工作变得更加困难。     

Visual Tools for Natural Language Processing

We describe GATE, the General Architecture for Text Engineering, an integrated visual development environment to support the visual assembly, execution and analysis of modular natural language processing systems. The visual model is an executable data flow program graph, automatically synthesised from data dependency declarations of language processing modules. The graph is then directly executable: modules are run interactively in the graph, and results are accessible via generic text visualisation tools linked to the modules. These tools lighten the ‘cognitive load’ of viewing and comparing module results by relating data produced by modules back to the underlying text, by reducing the amount of search in examining results, and by displaying results in context. Overall, the GATE integrated visual development environment leads to rapid understanding of system behaviour and hence to rapid system refinement, therefore demonstrating the utility of visual programming and visualisation techniques for the development of natural language processing systems.     

一种带有密钥的.EXE文件隐秘传输方法

为解决电子商务中各种文件的隐秘传输问题,在分析可执行文件特点的基础上,结合空域信息隐藏原理,设计实现了一种带有密钥的.EXE文件隐密传输方法.该方法在密钥的作用下,将.EXE文件的比特流,隐藏在载体图像较低的3个比特位上.方法已采用Matlab编程实现,实验表明采用该方法进行可执行文件隐藏时,嵌入前后图像的PSNR大于30dB,人类的视觉根本无法区分.而且恢复的可执行文件同正常文件一样,其运行未受任何影响.算法的隐藏效果较好,可以满足文件的隐秘传输需要.     

基于IDA-Pro的软件逆向分析方法

二进制程序转换作为软件逆向分析的主要手段发挥着积极作用。该文给出一种程序转换方法,应用软件二进制程序经IDA Pro反汇编得汇编语言程序,依据下推自动机原理设计汇编文法识别该汇编文件、制定相应的转换规则和优化措施将汇编语言转换成中间语言。转换所得中间语言可读性较强,具有通用性且易于理解。该方法达到了较高的自动化程度,缩小了目标程序的代码量,其应用可有效地减少软件分析和调试人员在追踪代码时所需的时间和工作量。给出应用上述方法进行程序转换的实例。     

Syntax-Directed Pretty Printing—A First Step Towards a Syntax-Directed Editor

A language-independent syntax-directed pretty printer has been implemented as the first step towards building a language-independent syntax-directed editor. The syntax-directed pretty printer works in two phases: the grammar processing phase and the program processing phase. In the grammar processing stage, a grammar which contains a context-free grammar and information for the parser and pretty printer is processed and all files needed by the second phase are written. With these files, the syntax-directed pretty printer works for the language of the grammar. The syntax-directed editor would use the same grammar processing phase to construct the files needed to make it work for a specific language. In the program processing phase, programs in the language of the grammar are parsed and parse trees are built. If syntax errors are found, error messages are produced and error recovery is done. The parse trees are pretty printed according to the pretty printer specifications given in the grammar, resulting in well-indented, syntactically clear programs.     

CAD／CAPP／CAM系统中的产品数据管理开发策略

产品数据管理是集成化ＣＡＤ／ＣＡＰＰ／ＣＡＭ系统的关键，首先介绍一个基于ＳＴＥＰ标准的ＣＡＤ／ＣＡＰＰ／ＣＡＭ系统的开发情况，然后介绍其中数据管理软件的开发策略，系统结构与特点及在集成系统中应用的一些问题，最后给出一个应用实例。     

Legacy system program transformation by Lyee methodology

Based on the comparative review of several approaches to legacy system conversion and revitalization, the Lyee methodology application for the issue is presented to clarify its idea, the associated procedure, and the implemented tools. It could be said that with the tools and manual developed by ICBSM&T, the mechanical transformation of the conventional program to a Lyee-structured one becomes possible as long as the programs are made in a procedure-oriented language. In addition to the program structure conversion, the Lyee methodology permits people to choose any application language in the transformed program. At the same time, quite a new approach related to the system conversion is introduced, in which the chunk of data extracted from an old program is edited to make a new conventional structure program that has a logical sequence instead of a Lyee type of declarative program. These features can be realized through the concept of LyeeBELT, which is a set of word-information about the attributes, formulae, and conditions for an independent data item.

The overall workflow of the legacy program transformation is shown in the following.

A critical part in its implementation is the feasibility study (pre-analysis) stage where necessary information is supposed to be secured, and an appropriate plan and policy about the system to be revitalized in the new system environment should be clarified so as to customize the tools accordingly. If the initial process is completed, the mechanical legacy system conversion will be realized by registering the parameters in the tool, and the reestablishment of business knowledge in the LyeeBELT will be enabled. With the regulated business logic on the LyeeBELT, the program maintenance afterwards becomes drastically simplified and stable without the ‘spaghetti’ problem, so that software evolution can be possible.     

Meta-interpreters and partial evaluation in Parlog

Since logic programs are executable specifications, the main concern of logic programming, producing efficient programs, is tangential to the mainstream of formal methods. A fashionable automatic transformation technique for producing efficient programs, partial evaluation, applied to the concurrent logic programming language Parlog is discussed.     

An integrated paleomagnetic analysis program for stratigraphy labs and research projects

This paper describes a Windows-based paleomagnetic analysis program integrates on-screen visualization and analysis of paleomagnetic data and printing graphic outputs. The program is easy to understand and use with its graphic user interface. It accepts fixed length or delimited data files, each of which can contain up to 500 samples with a variable number of demagnetization steps (up to 50). The integrated toolboxes accept keyboard or copy-and-paste data input, and allow the user to calculate paleolatitudes, convert between spherical and Cartesian coordinates, and perform many functions of the main program.The main program converts an ASCII data file into a specially formatted file (*.mag) for random read/write access. After conversion, the *.mag file is automatically opened, and a list of sample is displayed in a small window. When a sample on the list is clicked, the associated demagnetization data are displayed in a nearby window. The user can visualize the data using the Zijderveld (/modified Zijderveld) projection and the stereographic (/Lambert equal-area) projection simultaneously or individually. The data visualized can be in either geographic or tilt-corrected coordinates, from all or certain demagnetization steps of a sample, or from a single demagnetization step of all samples. Characteristic directions of each sample are derived from a three-dimensional least-squares fit of selected demagnetization steps by principal component analysis (PCA). Mean directions from “Fisher” analysis are computed from click-selected samples using a designated demagnetization step or the characteristic directions. These mean directions are automatically computed for each polarity by a routine that compensates for pervasive overprint directions, and that can also utilize subjective weighting of sample directions. The graphic outputs can be printed on paper or screen-captured into graphic software, and the analytical results can be copied and pasted into word-processing programs.     

NDAUTO：An Experimental Software Automation System

This paper describer the design and implementation of an experimental software automation system(NDAUTO).By combining the transformational and procedural approaches in software gutomation,the system can tansform software unctional specifications written in a graphical specification language GSPEC to executable programs sutomatically,The equivalence between a specification and its corresponding program can be guaranteed by the system,and the correctness of the specification can also be validated.The main new points of the work lie in the design of the specification languange,the transformation mechanism and the correctness validation of the specification.