Web应用代码生成系统的设计与实现

代码生成工具的使用可以大幅度减少开发人员编写重复性代码的工作量,提高Web应用开发的质量和效率。在代码生成系统中,设计一种基于MVC设计模式的新型Web应用开发框架,将Web应用分为视图层、控制层和模型层,每层各司其职,代码结构清晰,在此基础上采用JET模板和Xpath相结合的代码生成方法生成重复性代码。实验证明,该系统可快速构建Web应用。     

一个基于Java的代码生成工具的设计与实现

给出了一个基于Java的代码生成工具的设计与实现方案。该方案基于数据模型来生成代码,允许用户自定义代码模板,实现了数据模型驱动的开发模式。该代码生成工具具有良好的可扩展性和灵活性,用户可根据需要自定义数据模型、代码模板,从而不断丰富代码生成工具的基础数据。     

基于xUML的模型一致性问题研究

xUML是一种统一建模语言UML的扩展语言,可用于实现自动代码生成。针对xUML代码生成过程中出现的模型不一致问题,文中提出了一种基于xUML类图和活动图的模型完整性和一致性校验方法。首先给出了模型完整性和一致性的校验规则,其次给出了基于规则伪代码形式的算法描述,最后利用工具结合一个具体的实例对完整性和一致性检验算法进行验证。实验结果表明,该方法可以用于对类图和活动图的完整性和一致性验证。     

基于XML的代码自动生成工具

代码自动生成作为一种程序自动化技术,可有效解决现代大规模软件开发过程中遇到的重复编写代码问题,提高了软件开发的效率和质量。文中介绍了一种基于XML的代码生成技术,并以XML转换技术为基础,给出了XML的代码生成工具的结构设计,及其实现框架和关键步骤。以该工具在雷达建模仿真过程中的应用实例,验证了基于XML的代码生成工具可减少重复代码编写,降低因手工编写带来的编码错误,从而提高了代码的编写质量及效率,使大规模软件开发和维护更简便。     

基于XML代码生成技术的应用研究

代码生成技术作为一种程序自动化技术具有代码生成模板维护和扩展简单、可支持多操作平台并且易于实现等特点,可提高软件开发的效率和质量。文中介绍了一种基于XML的代码生成器的实现框架和关键步骤,并给出了部分软件代码程序。     

一种自动生成状态机RTL代码的方法

集成电路设计中,状态机的代码实现具有一定规律性.根据该规律通过某种方法自动生成状态机RTL代码,可以提高设计设计效率.此项方法首先由Matlab中的Stateflow工具输入状态转移图,利用基于Tcl/Tk的软件提取其中有用信息,再进行状态机RTL代码生成,完成转换过程.该软件的成功设计和应用证明了此方法的可行性和实用性.     

特定领域建模方法和代码生成的研究

特定领域建模（Domain-Specific Modeling ,DSM ）提高了软件的抽象水平,DSM 用模型表示用户的需求,然后通过生成器,直接把模型中的信息提取出来并转换成代码,实现了代码的自动生成。研究了特定领域建模语言、生成器和领域框架,总结了M etaEdit＋下实现DSM的一般过程及其使用的相关技术,并介绍了代码生成的具体过程。基于M etaEdit＋,实现了电子万年历的元建模和领域建模,并通过提出的深度优先遍历的代码生成算法,实现了电子万年历代码的自动生成。     

基于单片机的快速代码生成方法

基于模型设计是国外流行的一种先进的嵌入式系统开发方式,该方式主要利用开发工具Simulink以及Matlab的RTW（Real-TimeWorkshop）工具箱的代码生成功能,采用IAR作为中间工具,将RTW生成的C语言代码转为为在单片机MSP430F2252中可以运行的HEX文件,最后通过Protues软件来验证代码的正确性。该方法无需设计者精通各种编程语言,只需了解设计规范与实现原理,极大地降低了嵌入式系统开发难度,缩短了开发周期,并且能够保证代码的高效性、可靠性。     

面向VLIW结构的高性能代码生成技术

DSP处理器通过采用VLIW结构获得了高性能,同时也增加了编译器为其生成汇编代码的难度.代码生成器作为编译器的代码生成部件,是VLIW结构能够发挥性能的关键.由此提出并实现了一种基于可重定向编译框架的代码生成器.该代码生成器充分利用VLIW的体系结构特点,支持SIMD指令,支持谓词执行,能够生成高度指令级并行的汇编代码,显著提高应用程序的执行性能.     

移动计算中基于椭圆曲线的匿名签名算法

移动代码(例如移动代理)在异地执行签名时往往不希望暴露其所有者的私有密钥,本文提出了一种基于椭圆曲线的移动代码匿名签名算法,依据该算法,移动代码所有者可以利用椭圆曲线根据自己的身份信息为移动代码生成一个认证矢量和一个临时性密钥对,并通过它们实现了移动代码匿名签名以及签名后的不可否认性.该算法除具有匿名性和不可否认性以外,还具有高效性、保密性和不可伪造性等特点,可广泛应用于各种具有代码移动特性的移动计算.     

RTW技术在轮机模拟器中的应用

文中介绍了轮机模拟器中船舶主机数学模型的构建过程中,利用MATLAB/Simulink中代码转换工具,将Simulink中搭建的船舶主机模型转换为C＋＋代码。并通过进一步开发,实现了实时修改模块的参数,并将该模型产生的数据存入SQL数据库中,以供轮机模拟器的其他部分调用。并且以基于virtools的船舶主机虚拟操作系统为例,介绍了该技术的具体应用。减轻了编写代码的繁琐,满足了轮机模拟器的实时性要求,为模拟器的开发带来方便。     

基于NARX非线性辨识技术的航空发动机嵌入式机载模型计算机实现

针对航空发动机控制系统中机载模型难以实现的问题,设计一种将NARX非线性辨识模型移植入嵌入式高性能处理器从而实现机载模型的方法。应用NARX非线性辨识技术,对某型涡扇发动机试车数据进行系统辨识并建立实时建模;接着,将辨识模型通过代码生成技术载入TMS320C6747控制模块;最后,经过适当接口修改,完成机载模型计算机的实现并对其进行实验验证。结果表明,所辨识模型具有较高精度,且载入DSP平台后精度可达92%,满足航空发动机系统对机载模型的要求。     

Click and code [automatic code generation]

Automatic code generation already plays a valuable role in embedded development. Engineers are turning to advanced software tools that generate code automatically, both during the prototyping stage of the project and when production code is required. At the prototyping stage, automatic code generation can greatly accelerate the development process, allowing many different algorithms to be tried in a shorter period. Furthermore, because there is no significant time penalty for trying alternative solutions, automatic code generation tools positively encourage innovation, eliminating the temptation to re-use previously developed code in compromised solutions. The specification that previously would have been handed to a software engineer for hand coding is now used as an 'executable specification'. In addition to forming the basis for code generation this specification can be used to develop test procedures, that can be applied both in simulation and on the real product. A further advantage of this approach is that algorithm developers can test their ideas without having to wait until the associated code is ready for downloading to a target processor. This not only benefits the algorithm designer, but also frees the software engineer from the routine coding of algorithms, allowing greater effort to be devoted to more challenging issues     

Phase-Coupled Mapping of Data Flow Graphs to Irregular Data Paths

Many software compilers for embedded processors produce machine code of insufficient quality. Since for most applications software must meet tight code speed and size constraints, embedded software is still largely developed in assembly language. In order to eliminate this bottleneck and to enable the use of high-level language compilers also for embedded software, new code generation and optimization techniques are required. This paper describes a novel code generation technique for embedded processors with irregular data path architectures, such as typically found in fixed-point DSPs. The proposed code generation technique maps data flow graph representation of a program into highly efficient machine code for a target processor modeled by instruction set behavior. High code quality is ensured by tight coupling of different code generation phases. In contrast to earlier works, mainly based on heuristics, our approach is constraint-based. An initial set of constraints on code generation are prescribed by the given processor model. Further constraints arise during code generation based on decisions concerning code selection, register allocation, and scheduling. Whenever possible, decisions are postponed until sufficient information about a good decision has been collected. The constraints are active in the "background" and guarantee local satisfiability at any point of time during code generation. This mechanism permits to simultaneously cope with special-purpose registers and instruction level parallelism. We describe the detailed integration of code generation phases. The implementation is based on the constraint logic programming (CLP) language ECLiPSe. For a standard DSP, we show that the quality of generated code comes close to hand-written assembly code. Since the input processor model can be edited by the user, also retargetability of the code generation technique is achieved within a certain processor class. This revised version was published online in July 2006 with corrections to the Cover Date.     

采用多级查找表的定/变长解码引擎

本文讨论了采用查找表的ＰＶＬＤ的设计和优化，并推导出求ＬＵＴ表项数的具体公式．同时，本文在充分考查了ＦＬＤ和ＶＬＤ的内部联系的基础上，设计了一种定／变长引擎，利用其中的两个桶形移位器，将定长解码器和变长解码器统一在同一电路中，可根据需要解相应长度的定长码或变长码，而且还能处理具有多个Ｈｕｆｆｍａｎ变长码表的情况．本文最后给出了实验结果．     

Engine Fault Analysis: Part II?Parameter Estimation Approach

The general fault analysis problem can be divided into two parts: fault detection and diagnosis (location). Fourier series, autocorrelation, and other techniques have been used for fault detection. However, these approaches cannot be utilized for locating the faults. In this paper a methodology is presented to locate faulty cylinder(s). The procedure involves the development of a mathematical model of the engine dynamics. This model takes into consideration the cylinder gas pressure, engine inertia, and load. The resultant torque is computed by using parameter estimation techniques. The parameter estimation technique employed can determine time-varying parameters without prior knowledge of the structure of the parameter. In the problem at hand, this is an important requirement. The resultant torque is the net of the cylinder gas torque and the frictional torque. The model and the estimation procedure have been verified by performing tests on a single-cylinder engine. A discriminant function has been defined to classify the performance of each cylinder. Our results indicate that the amplitude of the resultant torque can be used to identify the faulty cylinder(s). We have verified this approach by tests and studies on a six-cylinder engine. In our experiments we have studied cases involving one or two faulty cylinders.     

基于Matlab的DSP实验设计

本文以开发三相SPWM调制系统为例,详细阐述了基于Matlab/Simulink的DSP实验设计与实现.传统的DSP代码开发周期较长,效率不高.Matlab公司的Embedded Target for TI DSP可解决上述问题,用户通过使用该模块,不仅可以进行电路的系统级仿真,还可编译生成相应的C语言代码,进行算法的探索与设计思路的验证.通过Matlab先仿真后直接生成DSP代码进行实验的方式,使学生加深对DSP的认识,并能很快独立用DSP进行开发.     

Code Generation Framework for Grid Development

1Introduction Withrapidincreasinginnetworktechnologyanddis tributedcomputing,gridhasemergedfromitsinitial scientificbackground[1]andmadefirstattemptstostart acommercialusagewithaccesstonongrid relatedpro fessionalsandend users[2-5].Significantworkhasbeen …