The appearance of model-driven engineering (MDE) has invigorated research on domain-specific languages (DSLs) and automatic code generation. MDE uses models to build software, thereby displacing source code as the dev...
详细信息
The appearance of model-driven engineering (MDE) has invigorated research on domain-specific languages (DSLs) and automatic code generation. MDE uses models to build software, thereby displacing source code as the development process\'s main feature. DSLs provide easy, intuitive descriptions of the system using graphic models. In this new context, DSLs facilitate work in the first design stages. In addition, MDE helps reduce DSL development costs. It therefore represents a synergistic union that can significantly improve software development.
In developing countries like India, the traffic on roads is highly heterogeneous in nature, with vehicles of widely varying static and dynamic characteristics. In this type of traffic, vehicles do not follow lane disc...
详细信息
In developing countries like India, the traffic on roads is highly heterogeneous in nature, with vehicles of widely varying static and dynamic characteristics. In this type of traffic, vehicles do not follow lane discipline and they move freely over the entire width of roadway based on availability of space, To study this type of complex traffic flow and associated vehicular interactions, simulation is considered as an effective tool. An object-oriented methodology (OOM) for heterogeneous traffic simulation is proposed in this paper with focus on mid-block and intersection flow modeling. The paper presents the basics and advanced features of object-oriented programming (OOP) in detail in the context of traffic flow. The sample C++ code is discussed in detail to demonstrate the implementation of OOP features, such as encapsulation, inheritance and polymorphism. The contribution of this research work is the development of software objects for various components such as vehicle, traffic, link and node. This software can be adopted for heterogeneous traffic simulation programs, in general. (C) 2009 Elsevier Ltd. All rights reserved.
With increasing use of component-based development (CBD), the process for selecting software from repositories is a critical concern for quality systems development. As support for developers blending in-house and thi...
详细信息
With increasing use of component-based development (CBD), the process for selecting software from repositories is a critical concern for quality systems development. As support for developers blending in-house and third party software, the context-driven component evaluation (CdCE) process provides a three-phase approach to software selection: filtering to a short list, functional evaluation and ranking. The process was developed through iterative experimentation on real-world data. CdCE has tool support to generate classifier models, shortlists and test cases as artefacts that provide for a repeatable, transparent process that can be reused as the system evolves. Although developed for software component selection, the CdCE process framework can be easily modified for other selection tasks by substituting templates, tools, evaluation criteria and/or repositories. In this article the authors describe the CdCE process and its development, the CdCE framework as a reusable pattern for software selection and provide a case study where the process is applied.
Using the IAPWS-95 formulation, an ActiveX component SteamTablesIIE in Visual Basic 6.0 is developed to calculate thermodynamic properties of pure water as a function of two independent intensive variables: (1) temper...
详细信息
Using the IAPWS-95 formulation, an ActiveX component SteamTablesIIE in Visual Basic 6.0 is developed to calculate thermodynamic properties of pure water as a function of two independent intensive variables: (1) temperature (T) or pressure (P) and (2) T, P, volume (V), internal energy (U), enthalpy (H), entropy (S) or Gibbs free energy (G). The second variable cannot be the same as variable 1. Additionally, it calculates the properties along the separation boundaries (i.e., sublimation, saturation, critical isochor, ice I melting, ice III to ice IIV melting and minimum volume curves) considering the input parameter as T or P for the variable 1. SteamTablesIIE is an extension of the ActiveX component SteamTables implemented earlier considering T (190 to 2000 K) and P (3.23 x 10(-8) to 10000 MPa) as independent variables. It takes into account the following 27 intensive properties: temperature (T), pressure (P), fraction, state, volume (V), density (Den), compressibility factor (Z(o)), internal energy (U), enthalpy (H), Gibbs free energy (G), Helmholtz free energy (A), entropy (S), heat capacity at constant pressure (C(p)), heat capacity at constant volume (C(v)), coefficient of thermal expansion (CTE), isothermal compressibility (Z(iso)), speed of sound (VelS), partial derivative of P with T at constant V (dPdT), partial derivative of T with V at constant P (dTdV), partial derivative of V with P at constant T (dVdP), Joule-Thomson coefficient (JTC), isothermal throttling coefficient (IJTC), viscosity (Vis), thermal conductivity (ThrmCond), surface tension (SurfTen), Prandtl number (PrdNum) and dielectric constant (DielCons). (C) 2009 Elsevier Ltd. All rights reserved.
Algorithms for discrete optimization of proteins play a central role in recent advances in protein structure prediction and design. We wish to improve the resources available for computational biologists to rapidly pr...
详细信息
Algorithms for discrete optimization of proteins play a central role in recent advances in protein structure prediction and design. We wish to improve the resources available for computational biologists to rapidly prototype such algorithms and to easily scale these algorithms to many processors. To that end. we describe the implementation and use of two new open source resources. citing potential benefits over existing software. We discuss CHOMP. a new object-oriented library for macromolecular optimization, and SHARPEN, a framework for scaling CHOMP scripts to many computers. These tools allow users to develop new algorithms for a variety of applications including protein repacking, protein-protein docking, loop rebuilding, or homology model remediation. Particular care was taken to allow modular energy function design;. protein conformations may Currently be scored using either the OPLSaa molecular mechanical energy function or an all-atom semiempirical energy function employed by Rosetta. (C) 2009 Wiley Periodicals, Inc. J Comput Chem 30: 999-1005, 2009
This paper presents results from a quasi-experiment that investigates how the sequence in which maintenance tasks are performed affects the time required to perform them and the functional correctness of the changes m...
详细信息
This paper presents results from a quasi-experiment that investigates how the sequence in which maintenance tasks are performed affects the time required to perform them and the functional correctness of the changes made. Specifically, the study compares how time required and correctness are affected by (1) starting with the easiest change task and progressively performing the more difficult tasks (Easy-First), versus (2) starting with the most difficult change task and progressively performing the easier tasks (Hard-First), In both cases, the experimental tasks were performed on two alternative types of design of a Java system to assess whether the choice of the design strategy moderates the effects of task order on effort and correctness. The results show that the time spent on making the changes is not affected significantly by the task order of the maintenance tasks, regardless of the type of design. However, the correctness of the maintainability tasks is significantly higher when the task order of the change tasks is Easy-First compared to Hard-First, again regardless of design. A possible explanation for the results is that a steeper learning curve (Hard-First) causes the programmer to create software that is less maintainable overall. (C) 2008 Elsevier B.V. All rights reserved.
We present here SaX (Self-energies and eXcitations), a plane-waves package aimed at electronic-structure and optical-properties calculations in the GW framework, namely using the GW approximation for quasiparticle pro...
详细信息
We present here SaX (Self-energies and eXcitations), a plane-waves package aimed at electronic-structure and optical-properties calculations in the GW framework, namely using the GW approximation for quasiparticle properties and the Bethe-Salpeter equation for the excitonic effects. The code is mostly written in FORTRAN90 in a modern style, with extensive use of data abstraction (i.e. objects). Sax employs state of the art techniques and can treat large systems. The package is released with an open source license and can be also download from http://***/.
Accurate prediction of contaminant migration in surface and ground water bodies, including interaction with aquifer and hyporheic zone materials requires reactive transport modeling. The increasing complexity and the ...
详细信息
Accurate prediction of contaminant migration in surface and ground water bodies, including interaction with aquifer and hyporheic zone materials requires reactive transport modeling. The increasing complexity and the procedure-oriented type of programming often used in reactive transport hinder codes reuse and transportability. We present a Fortran 90 module using object-oriented concepts that simulates complex hydrobiogeochemical processes (CHEPROO, CHEmical PRocesses object-oriented). CHEPROO consists of a general structure with two classes. The Nodal Chemistry class accounts for the description of local chemistry and geochemical state variables. As such, it provides many functions related to basic operations (evaporation, mixing, etc.) and can easily grow on this direction (extreme dry conditions, biochemical state variables, etc.). The Chemical System class includes kinetic and thermodynamic models that describe reactions between and within phases. As such, it can grow in the direction of increasingly complex chemical systems (solid solutions, microorganisms as individual phases, etc.), without loss in the handling of simple problems. These two classes are overlaid by CHEPROO, a general structure designed for interaction with other codes. CHEPROO can be used as a geochemical tool for the modeling of complex processes such as biodegradation or evaporation at high salinities. However, many functions CHEPROO are devoted to coupling a broad range of chemical processes to other phenomena (flow, transport, mechanical). We have shown that reactive transport (based on either DSA or SIA approaches) could be easily implemented into existing conservative transport code with a minimal number of changes. (C) 2008 Elsevier Ltd. All rights reserved.
The object-oriented philosophy abstracts out the essential immutable qualities of the components of the finite element method into classes of objects. It facilitates easy modification capability without creating a rip...
详细信息
The object-oriented philosophy abstracts out the essential immutable qualities of the components of the finite element method into classes of objects. It facilitates easy modification capability without creating a ripple effect on the whole program and reduces the necessity of knowledge of the source code to a minimum level. This paper presents a prototype implementation of the development of a flexible computational platform based on an object-oriented approach and its application in a FORTRAN environment, which facilitates use of previously developed components. IDARC3D which is capable of linear and nonlinear, static as well as dynamic analyses of multistory three-dimensional buildings with, or without, energy dissipation devices developed in FORTRAN with conventional programming practices has been transformed to the object-oriented framework. By using the new object-oriented platform, some representative examples were analysed and the results were compared with the well-known software facilities. (C) 2009 Elsevier Ltd. All rights reserved.
Today, there's significant interest in functional languages and frameworks that fit the Web better than imperative languages. We explore Scala, an OO-functional language on the Java virtual machine, and Lift, a fr...
详细信息
Today, there's significant interest in functional languages and frameworks that fit the Web better than imperative languages. We explore Scala, an OO-functional language on the Java virtual machine, and Lift, a framework implemented on Scala's functional features. The Scala language offers functional programming features and asynchronous message-passing concurrency alongside a statically typed model. Lift exploits this model to offer secure, higher-level abstractions to Web developers.
暂无评论