API-Evolution Support with Diff-CatchUp

Applications built on reusable component frameworks are subject to two independent, and potentially conflicting, evolution processes. The application evolves in response to the specific requirements and desired qualities of the application's stakeholders. On the other hand, the evolution of the component framework is driven by the need to improve the framework functionality and quality while maintaining its generality. Thus, changes to the component framework frequently change its API on which its client applications rely and, as a result, these applications break. To date, there has been some work aimed at supporting the migration of client applications to newer versions of their underlying frameworks, but it usually requires that the framework developers do additional work for that purpose or that the application developers use the same tools as the framework developers. In this paper, we discuss our approach to tackle the API-evolution problem in the context of reuse-based software development, which automatically recognizes the API changes of the reused framework and proposes plausible replacements to the "obsolete" API based on working examples of the framework code base. This approach has been implemented in the Diff-CatchUp tool. We report on two case studies that we have conducted to evaluate the effectiveness of our approach with its Diff-CatchUp prototype.     

面向专家示例的Stack Overflow本体构造和推理研究

Stack Overflow是一个计算机领域的IT技术问答网站,为了获取问答网站中的专家示例并将其应用于API挖掘中,首先采用Scrapy爬虫框架技术获取Stack Overflow问答网站中的结构化数据,并存储在关系模式中;再使用本体建模工具Protégé构建本体,然后使用D2RQ工具实现对关系数据库的知识抽取,将关系模式转换为三元组形式的本体模型;同时,提出了一个面向专家示例的子本体抽取算法,用于从原本体中抽取出专家示例推理相关的子本体,并提出了若干条专家示例推理规则,能推导出专家所编写的代码示例。实验结果证明,从Stack Overflow本体模型中抽取的专家示例能提高API调用序列挖掘的准确率。     

Relational concurrent refinement part III: traces,partial relations and automata

Data refinement in a state-based language such as Z is defined using a relational model in terms of the behaviour of abstract programs. Downward and upward simulation conditions form a sound and jointly complete methodology to verify relational data refinements, which can be checked on an event-by-event basis rather than per trace. In models of concurrency, refinement is often defined in terms of sets of observations, which can include the events a system is prepared to accept or refuse, or depend on explicit properties of states and transitions. By embedding such concurrent semantics into a relational framework, eventwise verification methods for such refinement relations can be derived. In this paper, we continue our program of deriving simulation conditions for process algebraic refinement by defining further embeddings into our relational model: traces, completed traces, failure traces and extension. We then extend our framework to include various notions of automata based refinement.     

simpA: An agent-oriented approach for programming concurrent applications on top of Java

More and more aspects of concurrency and concurrent programming are becoming part of mainstream programming and software engineering, due to several factors such as the widespread availability of multi-core/parallel architectures and Internet-based systems. This leads to the extension of mainstream object-oriented programming languages and platforms-Java is a main example-with libraries providing fine-grained mechanisms and idioms to support concurrent programming, in particular for building efficient programs. Besides this fine-grained support, a main research goal in this context is to devise higher-level, coarse-grained abstractions that would help building concurrent programs, as pure object-oriented abstractions help building large component-based programs. To this end, in this paper we present simpA, a Java-based framework that provides programmers with agent-oriented abstractions on top of the basic OO layer, as a means to organize and structure concurrent applications. We first describe the application programming interface (API) and annotation framework provided to Java programmers for building simpA applications, and then we discuss the main features of the approach from a software engineering point of view, by showing some programming examples. Finally, we define an operational semantics formalizing the main aspects of this programming model.     

NGN基于Parlay API业务生成接口的研究与设计

ParlayAPI是下一代网络(NGN)中面向第三方业务生成接口的主流形式。文章从NGN业务生成接口的实现角度入手,对基于CORBA的ParlayAPI体系中框架和业务能力特征接口进行研究,分别设计出框架API和业务能力特征API的实现方案,并对方案中的映射问题作了进一步的分析与探讨。     

双析取逻辑程序设计基础（Ⅰ）

析取逻辑程序设计是传统逻辑程序设计最重要的扩充之一，本文通过一些实例说明，现存语义无法充分 表示信息的不完全性。为此，本文提出了双析取逻辑程序设计的概念，我们不仅从句法上将正规则析取逻辑程序推广为双析取逻辑程序。而且建立了一种高度直观，灵活的辩论语义框架ＢＤＡＳ。     

可拓检测中的待测物元转换问题研究与分析

以可拓检测为研究基础,提出第3类检测问题：待测物元转化问题,即新的检测环境下的可测物元与待测物元的互换问题。针对该问题的特殊性,以基于神经网络的检测模型为问题求解框架,可拓变换与关联函数作为遗传算法的设计准则,提出基于可拓遗传算法和神经网络的待测物元转化问题的解决方法。通过实际例子的应用验证了该方法的可行性。     

基于NGN的脚本语言CPL与SCML

主要描述下一代网络NGN中基于XML业务脚本语言的结构与框架。我们聚焦于由JAIN论坛开发的SCML，SCML被定性为一系列NGN业务脚本语言中的一种，这类语言都可以使用户相互交流、其灵活性、开放性为其他NGN API功能提供便利。对比了SCML与由IETF所定义的CPL(Call Processing Language)能和要求，并发现SCML的一些优势。     

CONCUR: A language for continuous, concurrent processes

Hendrix's robot modeling system presented a simulation method in which time is represented as a continuous phenomenon. This paper introduces the language CONCUR, which realizes Hendrix's concept through an extension of the LISP environment. CONCUR uses generalized procedures (scenarios) operating in a data-driven mode to implement Hendrix's events. The heart of CONCUR is a generalized pattern-matcher which permits operators within the patterns to bind variables and modify the match process. We include several detailed examples in addition to an implementation of the pattern matcher.     

On Transitions Between Representations: The Role of Contextual Reasoning in Calculus Problem Solving

This article argues for a shift in how researchers discuss and examine students' uses and understandings of multiple representations within a calculus context. An extension of Zazkis, Dubinsky, and Dautermann's (1996) visualization/analysis framework to include contextual reasoning is proposed. Several examples that detail transitions between modes of reasoning and how these transitions inform students' reasoning in a calculus context are discussed. These examples are used to provide evidence for the usefulness of the model for unpacking student reasoning.     

API Hook关键技术解析

本文分析了APIHook系统的实现结构和系统涉及的DLL注入和API拦截两项关键技术的多种实现途径,并结合应用给出了编程实现的方法。     

Windows API与DLL在iFIX开发中的应用

本文详细介绍了Windows API与DLL的功能和作用，并对怎样在iFIX的VB脚本中调用Windows API和开发DLL作了事例说明。     

MFC框架下Vega视景的视点控制技术

大范围战场环境的视景仿真中,仿真实体运动状态复杂多变。为解决这种视景仿真的逼真性问题,通过对观察者和目标间几何对应关系的分析,给出了三种控制模式：等距离模式、等速度模式、匀加速模式,设计了虚拟视景中视点控制的基本算法。在MFC框架下,应用Vega API函数实现C语言对Vega视景仿真平台的调用,实现了视点对目标的随动控制方法,解决了视景仿真系统中视点的随动控制问题。在视景仿真实验中,达到了对视点方式的灵活控制,具有较强的现实直观性,同时增强了视景的真实感和交互性。     

基于Java电子邮件系统的设计与实现

在介绍电子邮件系统SMTP和POP3协议,JavaMail API结构框架和核心类的基础上,笔者主要阐述的是如何利用JavaMailAPI结合Jsp编程实现电子邮件的收发系统,以实现用户的无障碍交流,系统的主要功能包括用户注册和登陆、接收和发送邮件及附件等管理。     

Parallel techniques in irregular codes: cloth simulation as case of study

When parallelizing irregular applications on ccNUMA machines several issues should be taken into account in order to achieve high code performance. These factors include locality exploitation and parallelism, as well as careful use of memory resources (memory overhead). An important number of numerical simulation codes are clear examples of irregular applications. Frequently these kinds of codes include reduction operations in their core, so that an important fraction of the computational time is spent on such operations. Specifically, cloth simulation belongs to this class of applications, being a topic of increasing interest in diverse areas, like in the multimedia industry. Moreover, when real time simulation is the aim, its parallelization becomes an important option.This paper discusses and compares different irregular reduction parallelization techniques on ccNUMA share memory machines. Broadly speaking, we may classify them into two groups: privatization-based and data partitioning-based methods. In this paper we describe a framework, based on data affinity, that permits to develop various algorithms inside the group of the data partitioning-based techniques. All these techniques and approaches are analyzed and adapted to the computational structure of a real, physically based, cloth simulator.     

Provisioning of power event APIs as a mobile OS facility

Monitoring various hardware and software events for energy consumption is essential for energy management in mobile devices. However, current mobile operating systems (OS) lack monitoring functionality and do not provide sufficient information of this kind. In this paper, we propose PEMOS (Power Events Monitor for Mobile Operating Systems), a framework for power event APIs for mobile devices, that provides a wide spectrum of energy-related information, enabling in-depth analysis of energy problems. PEMOS provides a set of well-defined APIs as a mobile OS facility, defining various energy-related system events as power events. These are classified into system events and application events, encompassing extensive and fine-grained power-related events. Benefits of PEMOS include extensive coverage of power events, high portability across various platforms, and efficient API implementation. The framework structure is portable across multiple devices, and the standard ioctl-based API implementation enables the same operations on different devices without system modification. We implemented PEMOS on the Android platform to evaluate its efficacy and usefulness. The experimental results and case studies confirm that PEMOS is effective and useful for a range of energy management systems, with minimal overhead.     

On the Learnability of Rich Function Classes

The probably approximately correct (PAC) model of learning and its extension to real-valued function classes sets a rigorous framework based upon which the complexity of learning a target from a function class using a finite sample can be computed. There is one main restriction, however, that the function class have a finite VC-dimension or scale-sensitive pseudo-dimension. In this paper we present an extension of the PAC framework with which rich function classes with possibly infinite pseudo-dimension may be learned with a finite number of examples and a finite amount of partial information. As an example we consider learning a family of infinite dimensional Sobolev classes.     

基于J2ME的移动视频技术研究

基于J2ME体系框架,结合MMAPI技术,设计并实现了一个移动媒体播放器。重点阐述了MMAPI技术及播放器类的设计。     

OCCN: a NoC modeling framework for design exploration

The On-Chip Communication Network (OCCN) project provides an efficient framework, developed within SourceForge, for the specification, modeling, simulation, and design exploration of network on-chip based on an object-oriented C++ library built on top of SystemC. OCCN is shaped by our experience in developing communication architectures for different System-on-Chip. OCCN increases the productivity of developing communication driver models through the definition of a universal Application Programming Interface (API). This API provides a new design pattern that enables creation and reuse of executable transaction level models across a variety of SystemC-based environments and simulation platforms. It also addresses model portability, simulation platform independence, interoperability, and high-level performance modeling issues.     

C编写Tcl文件系统监测扩展

ReadDirectoryChangesW是Windows系统下用于监测文件系统变化的API函数。使用Tcl的C扩展API对其进行必要的整合与包装,分别从同步调用与异步调用两个角度介绍了如何实现阻塞与非阻塞的Tcl模块,并在此基础上结合Tcl的时间通知机制,实现了单线程非阻塞的文件监控模式。