Hierarchical development of programming languages

The experience in designing large software systems shows that even the definitions of a programming language can be seen as the application of specific implementation and formalization techniques rather than as the result of a «designing art». In this context, a formalism is proposed here as a tool for defining conventional high level programming languages. The formalism is an algebraic model supporting the definition of representational entities such as types. A Type is a set of data and operations on them. An isomorphism between language components and types realizes an isomorphism between the language and its specification on the model. Then, the definition of a language can be performed by stepwise definitions of the types representing the language components. So the model is also a language development tool. Stepwise definition methodologies are also investigated and two are the proposed ones: the horizontal, methodology and the vertical methodology. In particular, the vertical methodology defines languages by the development of a hierarchy of abstraction levels, each corresponding to one class of languages: The last class only contains the language being defined.     

Watch out, Tiger Woods![golf playing robot]

This article describes the development of an autonomous robotic system for playing mini-golf. The system was designed and built to serve as a demonstration of robotic application for engineering students. The system was built using a Yasakawa robot fitted with two arms. The software was developed to control the machine using the C++ language. Standard C++ libraries were used in addition to communication libraries provided by the Yasakawa Corporation. The current configuration works with Microsoft Windows NT and an Ethernet environment. This article describes the hardware and software design aspects of this machine.     

Dense and Sparse Matrix Classes Using the C++ Standard Template Library

The C++ programming language has undergone significant changes since its inception in the 1980s, but has now reached a relatively steady state. Standard C++ now includes a general library of container classes, the Standard Template Library (STL). These developments are rapidly changing the styles used in C++ class programming. The paper has dual purposes: it provides an introduction to STL for C++ programmers, and it develops an efficient matrix class library, built upon STL, which provides functionality useful in areas such as computational economics, finance, mathematical programming and statistics. This library, which is freely available, comprises a full set of vector and matrix operations using both dense and sparse implementations. The paper discusses approaches towards and pitfalls in constructing C++ concrete data types, and has references for further on-line information.     

Recovering UML class models from C++: A detailed explanation

An approach to recovering design-level UML class models from C++ source code to support program comprehension is presented. A set of mappings are given that focus on accurately identifying such elements as relationship types, multiplicities, and aggregation semantics. These mappings are based on domain knowledge of the C++ language and common programming conventions and idioms. Additionally, formal concept analysis is used to detect design-level attributes of UML classes. An application implementing these mappings is used to reverse engineer a moderately sized, open-source application and the resultant class model is compared against those produced by other UML reverse engineering tools. This comparison shows that the presented mapping rules effectively produce meaningful and semantically accurate UML models.     

Scopira: an open source C++ framework for biomedical data analysis applications

In many biomedical research laboratories, data analysis and visualization algorithms are typical prototypes using an interpreted programming language. If performance becomes an issue, they are ported to C and integrated with interpreted systems, not fully utilizing object‐oriented software development. This paper presents an overview of Scopira, an open source C++ framework suitable for biomedical data analysis and visualization. Scopira provides high‐performance end‐to‐end application development features, in the form of an extensible C++ library. This library provides general programming utilities, numerical matrices and algorithms, parallelization facilities, and graphical user interface elements. Copyright © 2008 John Wiley & Sons, Ltd.     

基于C++语言的雷达系统组件化建模与仿真

传统的基于面向过程式语言的雷达仿真系统存在功能耦合严重,运行速度慢,开发难度大的问题。为了降低雷达仿真系统的开发难度,提高程序复用性,利用C++语言面向对象编程的特性和软件工程中组件复用的思想,设计了一种基于C++语言的雷达系统建模与仿真方法,将雷达系统各个组成部分包括资源调度、发射机、天线、回波生成、接收机、信号处理和数据处理抽象成单个功能组件分别进行开发,然后根据雷达系统工作顺序将各个组件集成在一起,实现了一个包含雷达参数设置、场景设置、数据存储和显控终端的完整的雷达仿真系统。仿真实验结果表明组件化雷达仿真系统运行正确,目标探测误差符合要求,航迹显示正常,并且具有较好的程序复用性和扩展性,促进了现代雷达仿真的快速应用。     

A UML-based static verification framework for security

Secure software engineering is a new research area that has been proposed to address security issues during the development of software systems. This new area of research advocates that security characteristics should be considered from the early stages of the software development life cycle and should not be added as another layer in the system on an ad-hoc basis after the system is built. In this paper, we describe a UML-based Static Verification Framework (USVF) to support the design and verification of secure software systems in early stages of the software development life-cycle taking into consideration security and general requirements of the software system. USVF performs static verification on UML models consisting of UML class and state machine diagrams extended by an action language. We present an operational semantics of UML models, define a property specification language designed to reason about temporal and general properties of UML state machines using the semantic domains of the former, and implement the model checking process by translating models and properties into Promela, the input language of the SPIN model checker. We show that the methodology can be applied to the verification of security properties by representing the main aspects of security, namely availability, integrity and confidentiality, in the USVF property specification language.     

基于OpenGL的湿地洪水演进模拟仿真系统的研究

作为松嫩平原洪水资源利用与湿地生态环境3S 系统中一个重要的组成部分湿地洪水演进模拟仿真系统的研制是一项复杂的专题。通过对系统目标以及可视化需求的分析, 对开放式的国际图形标准OpenGL 进行了阐述, 并以GIS 技术为基础, 采用面向对象的编程语言VC ++ , 结合OpenGL 的编程环境来实现扎龙湿地地形、地貌和洪水演进动态模拟的三维可视化效果。     

移动机器人视觉伺服系统上位机软件的设计与实现

针对移动机器人视觉伺服系统,采用C++语言设计了一款基于Qt的跨平台实时数据可视化上位机软件。该软件执行图像处理算法和数据分析,实现绘制移动机器人实时轨迹和实时参数曲线等功能。首先介绍了移动机器人的硬件组成和功能。其次阐述了上位机软件的开发环境和设计步骤,并详细叙述图像算法的运行流程和实时在线绘制波形图等功能。最后通过视觉伺服跟踪控制实验采集数据,并实时显示来验证所设计上位机软件功能的有效性。     

基于UML的城市应急联动系统建模

为了加快城市应急联动系统(CERS)的开发和利用现有的开发经验,研究了城市应急联动系统的结构.组成和功能,并分析了开发的关键问题.再运用软件工程领域内成熟的统一建模语言(UML),设计了一个完整的城市应急联动系统模型,包括城市应急联动系统用例图,类图、时序图、状态图、组件图、部署图等.采用Rational Rose工具实现CERS设计模型,目的是为系统最终用户和系统开发者提供统一的描述模型,指导系统开发人员迅速、准确、全面获取需求,规范系统的开发过程,优化系统结构,提高系统的开发效率.     

Comparing two types of engineering visualizations: task-related manipulations matter

This study focuses on the comparison of traditional engineering drawings with a CAD (computer aided design) visualization in terms of user performance and eye movements in an applied context. Twenty-five students of mechanical engineering completed search tasks for measures in two distinct depictions of a car engine component (engineering drawing vs. CAD model). Besides spatial dimensionality, the display types most notably differed in terms of information layout, access and interaction options. The CAD visualization yielded better performance, if users directly manipulated the object, but was inferior, if employed in a conventional static manner, i.e. inspecting only predefined views. An additional eye movement analysis revealed longer fixation durations and a stronger increase of task-relevant fixations over time when interacting with the CAD visualization. This suggests a more focused extraction and filtering of information. We conclude that the three-dimensional CAD visualization can be advantageous if its ability to manipulate is used.     

Knowledge-directed interpretation of mechanical engineeringdrawings

A methodology for the interpretation of images of engineering drawings is presented. The approach is based on the combination of schemata describing prototypical drawing constructs with a library of low-level image analysis routines and a set of explicit control rules applied by an LR(1) parser. The resulting system (Anon) integrates bottom-up and top-down processing strategies within a single, flexible framework modeled on the human perceptual cycle. Anon's structure and operation are described and discussed, and examples of its interpretation of real mechanical drawings are shown     

A Generic Integrated Line Detection Algorithm and Its Object–Process Specification

A generic integrated line detection algorithm (GILDA) is presented and demonstrated. GILDA is based on the generic graphics recognition approach, which abstracts the graphics recognition as a stepwise recovery of the multiple components of the graphic objects and is specified by the object–process methodology. We define 12 classes of lines which appear in engineering drawings and use them to construct a class inheritance hierarchy. The hierarchy highly abstracts the line features that are relevant to the line detection process. Based on the “Hypothesis and Test” paradigm, lines are detected by a stepwise extension to both ends of a selected first key component. In each extension cycle, one new component which best meets the current line's shape and style constraints is appended to the line. Different line classes are detected by controlling the line attribute values. As we show in the experiments, the algorithm demonstrates high performance on clear synthetic drawings as well as on noisy, complex, real-world drawings.     

闭合钢筋线形状的模糊识别方法

工程概预算中,关于闭合钢筋线形式的钢筋量计算要以其形状识别为基础。利用标准DXF文件格式的数据,基于闭合钢筋线几何信息,对钢筋线属性做了形式化表示,并以建筑图中最常见的四边形为例,建立一模糊识别模型。该模型以闭合钢筋线全体为论城,包含一组隶属函数和一系列判别规则。     

The object-oriented DFT program library S/PHI/nX

In order to simplify the development and implementation process of quantum mechanical algorithms, we developed a set of object-oriented C++ libraries which can exploit modern computer architectures. The libraries are characterized as follows: (i) State-of-the-art computer science techniques have been applied or developed in this work to provide language elements to express algebraic expressions efficiently on modern computer platforms. (ii) Quantum mechanical algorithms are crucial in the field of materials research. The new libraries support the Dirac notation to implement such algorithms in the native language of physicists. (iii) The libraries are completed by elements to express equations of motions efficiently which is required for implementing structural algorithms such as molecular dynamics. Based on these libraries we introduce the DFT program package S/PHI/nX.     

Making C++ objects persistent: The hidden pointers

C++ objects of types that have virtual functions or virtual base classes contain volatile (‘memory’) pointers. We call such pointers ‘hidden pointers’ because they were not specified by the user. If such C++ objects are made persistent, then these pointers become invalid across program invocations. We encountered this problem in our implementation of O++, which is a database language based on C++. O++ extends C++ with the ability to create and access persistent objects. In this paper, we describe the hidden pointers problem in detail and present several solutions to it. Our solutions are elegant in that they do not require modifying the C++ compiler or the semantics of C++. We also discuss another problem that arises because C++ allows base class pointers to point to derived class objects. C++ has emerged as the de facto standard language for software development, and database systems based on C++ have attracted much attention. We hope that the details and techniques presented will be useful to database researchers and to implementors of object-oriented database systems based on C++.     

Near-real-time satellite image processing: metacomputing in CC++

Metacomputing combines heterogeneous system elements in a seamless computing service. In this case study, we introduce the elements of metacomputing and describe an application for cloud detection and visualization of infrared and visible-light satellite images. The application processes the satellite images by using Compositional C++ (CC++)-a simple, yet powerful extension of C++-and its runtime system, Nexus, to integrate specialized resources, high-speed networks, parallel and distributed computing, and stereoscopic visualization in virtual reality (VR) displays