检索结果-内蒙古大学图书馆

Secondary Air System Component Modeling for Engine Performance Simulations

JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME 2009年第3期131卷 031202-1-9页

作者： Alexiou, A. Mathioudakis, K. Natl Tech Univ Athens Lab Thermal Turbomachines Athens 15710 Greece

This paper describes the modeling of typical secondary air system elements such as rotating orifices, seals, and flow passages with heat and work transfer from the surrounding surfaces. The modeling is carried out in an object-oriented simulation environment that allows the creation of different configurations in a simple and flexible manner. This makes possible to compare the performance between different designs of individual components or complete secondary air systems as well as integrate them directly in whole engine performance models. The modeling is validated against published experimental data and computational results. An example of implementation in an engine model is also presented.

关键词： engines heat transfer object-oriented methods orifices (mechanical)

来源：评论

学校读者我要写书评

暂无评论

Demand Based Test Case Generation for object oriented System

引用

IET SOFTWARE 2019年第5期13卷 403-413页

作者： Singh, Rajvir Bhatia, Rajesh Singhrova, Anita Deenbandhu Chhotu Ram Univ Sci & Technol Dept Comp Sci & Engn Sonipat Haryana India PEC Univ Technol Dept Comp Sci & Engn Chandigarh India

The object-oriented (OO) systems have emerged as the core systems in every field. Test case generation (TCG) for these systems has been identified as one of the crucial activity of software testing. Many researchers have been working in the area of TCG to raise the quality and effectiveness of the OO software systems. It is impossible to test the system exhaustively because of limitations of time, monetary cost and human efforts involved in the process of generation of all test cases. Presently, there is no adequate method that considers the contextual demand for the generation of test cases. Therefore, this study proposes a contextual demand-based TCG for OO systems using test paths or scenarios of sequence diagrams (SDs). Unlike the existing approaches, the proposed method considers flexible approach for generation of test cases as per the contextual demand. For the implementation of the proposed technique, two case studies, i.e. the sample SD and the SD of automated teller machine (ATM) system, have been considered. The evaluation of the proposed method showed the significant consideration of the user demand for generating the final test cases.

关键词： object-oriented methods program testing OO systems object-oriented systems core systems test case generation software testing OO software systems contextual demand-based TCG test paths ATM system demand-based TCG monetary cost sequence diagrams flexible approach

来源：评论

学校读者我要写书评

暂无评论

Numerical modeling of 3-D comb drive electrostatic accelerometers structure (method of levitation force reduction)

引用

COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 2009年第3期28卷 593-602页

作者： Wiak, Slawomir Smolka, Krzysztof Tech Univ Lodz Inst Mechatron & Informat Syst PL-90924 Lodz Poland

Purpose - The purpose of this paper is to discuss the numerical modelling of 3D structure of micro-electro-mechanical systems (MEMS) accelerometers. The general idea being discussed is the method of levitation force reduction, as the main Source of incorrect mathematical model of comb drive structure. Design/methodology/approach - Accelerometers design is a highly interdisciplinary area and, therefore, different methods and tools have to be exploited. Dynamic accelerometer behaviour modelling has been performed by use of a new object-oriented model (NOOM), based on complex computer field and mechanical models. Findings - The paper describes methods of levitation force reduction in electrostatic comb drive structures based on electrostatic structural models and finite elements method. Research limitations/implications - In the present work, the authors limit themselves to the electrostatic energy domains. Practical implications - Both, mechanical and electric models of accelerometers give the input data for defining the object-oriented model, based on Matlab-Simulink platform, fulfilling the general demand of dynamic behaviour simulation of comb drive structure. The proposed by authors methodology could give valuable contribution to MEMS design methodology. Originality/value - A new methodology has been successfully applied to calculation of levitation force in different geometries of comb drive. This methodology could be useful for multidisciplinary MEMS systems.

关键词： object-oriented methods Modelling Vectors Force measurement

来源：评论

学校读者我要写书评

暂无评论

objectStab - An educational tool for power system stability studies

引用

IEEE TRANSACTIONS ON POWER SYSTEMS 2004年第1期19卷 56-63页

作者： Larsson, M Lund Univ S-22100 Lund Sweden

Traditionally, the simulation of transient and voltage stability in power systems has been constrained to domain-specific tools such as Simpow, PSS/E, ETMSP, and EuroStag. While being efficient and thereby able to simulate large systems, their component models are often encapsulated and difficult or impossible to examine and modify. Also, these simulators often require substantial training and are therefore not ideal for normal classroom use. For academic and educational use, it is more important that the component modeling be transparent and flexible, and that students quickly get started with their simulations. This paper describes a freely available power system library called objectStab intended for power system stability simulations written in Modelica, a general-purpose object-oriented modeling language. All component models are transparent and can easily be modified or extended. Power system topology and parameter data are entered in one-line diagram form using a graphical editor. The component library has been validated, using comparative simulations with EuroStag.

关键词： object-oriented methods power system dynamic stability power system simulation

来源：评论

学校读者我要写书评

暂无评论

object-oriented concept analysis for software imodularisation

引用

IET SOFTWARE 2008年第2期2卷 134-148页

作者： Kim, H. H. Bae, D. -H. Korea Adv Inst Sci & Technol Dept Elect Engn & Comp Sci Taejon 305701 South Korea SolutionLink Corp Taejon South Korea

Modularity is one of the most important principles in software engineering and a necessity for every practical software. Since the design space of software is generally quite large, it is valuable to provide automatic means to help modularising it. An automatic technique for software modularisation using object-oriented concept analysis (OOCA) is proposed. The proposed technique is strongly inspired by the success of reverse engineering techniques based on formal concept analysis (FCA). However, our experience shows that FCA-based techniques generally result in fine-grained modules and, thus, may be inadequate for modularising large-scale designs. To overcome this weakness, the authors employ OOCA, a recent proposal for concept formulations. OOCA enables to provide coarse concepts as module candidates while keeping the advantage of FCA techniques. To the best of the authors' knowledge, it is the first work to apply OOCA in software engineering research. To illustrate the potential of the approach, the authors perform a software modularisation case study on a real insurance software design with comparison.

关键词： Formal methods fine-grained modules reverse engineering techniques object-oriented concept analysis Software engineering techniques object-oriented programming software engineering formal concept analysis object-oriented methods software modularisation

来源：评论

学校读者我要写书评

暂无评论

Estimation of feature vectors in object recognition processing

引用

KYBERNETES 2004年第1期33卷 133-140页

作者： Ruiz, D Pujol, FA Chamizo, JMG Pujol, M Rizo, R Univ Alicante Dept Tecnol Informat & Computac E-03080 Alicante Spain Univ Alicante Dept Ciencia Computac & Inteligencia Artificial E-03080 Alicante Spain

In most conventional pattern recognition methods, the first step is extracting features from objects. These features are always expressed in the form of feature vectors. Then, the distribution of feature vectors is estimated for each category. Finally, an unknown input pattern is assigned to the category with the maximum probability. In this work, we present a system that is able to recognize objects according to the likeness of feature vectors. A database, which consists of images that were identified from a vector of related features, is used by the system to discover these objects. If the resulting image features are compared with the ones included in the database, we obtain the object that has the highest similarity with the one we proposed The probability of success using our feature vector has been very high.

关键词： cybernetics modelling vectors object-oriented methods

来源：评论

学校读者我要写书评

暂无评论

A three-component method for timely detection of land cover changes using polarimetric SAR images

引用

ISPRS JOURNAL OF PHOTOGRAMMETRY AND REMOTE SENSING 2015年第Sep.期107卷 3-21页

作者： Qi, Zhixin Yeh, Anthony Gar-On Li, Xia Zhang, Xiaohu Sun Yat Sen Univ Sch Geog & Planning Guangzhou 510275 Guangdong Peoples R China Univ Hong Kong Dept Urban Planning & Design Hong Kong Hong Kong Peoples R China

This study proposes a new three-component method for timely detection of land cover changes using polarimetric synthetic aperture radar (PolSAR) images. The three components are object-oriented image analysis (OOIA), change vector analysis (CVA), and post-classification comparison (PCC). First, two PolSAR images acquired over the same area at different dates are segmented hierarchically to delineate land parcels (image objects). Then, parcel-based CVA is performed with the coherency matrices of the PoISAR data to detect changed parcels. Finally, PCC based on a parcel-based classification algorithm integrating polarimetric decomposition, decision tree algorithms, and support vector machines is used to determine the type of change for the changed parcels. Compared with conventional PCC based on the widely used Wishart supervised classification, the three-component method achieves much higher accuracy for land cover change detection with PoISAR images. The contribution of each component is evaluated by excluding it from the method. The integration of OOIA in the method greatly reduces the false alarms caused by speckle noise in PoISAR images as well as improves the accuracy of PoISAR image classification. CVA contributes to the method by significantly reducing the effect of the classification errors on the change detection. The use of PCC in the method not only identifies different types of land cover change but also reduces the false alarms introduced by the change in the environment. The three-component method is validated in land development detection, which is important to many developing countries that are confronting a growing problem of unauthorized construction land expansion. The results show that the three-component method is effective in detecting land developments with PoISAR images. (C) 2015 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS). Published by Elsevier B.V. All rights reserved.

关键词： Change detection algorithms Polarimetric synthetic aperture radar object-oriented methods Land cover RADARSAT-2

来源：评论

学校读者我要写书评

暂无评论

A UML-based approach for the development of shop floor control systems

引用

INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH 2009年第6期47卷 1601-1633页

作者： Yang, Dong Wu, Hongwei Tong, Lixin Shanghai Jiao Tong Univ Sch Mech Engn Dept Ind Engn Shanghai 200030 Peoples R China

As a key part of computer integrated manufacturing (CIM), shop floor control systems (SFCS) play an essential role in the effective operations of a shop floor. The development of SFCSs is an extremely complex process, given the requirements for synchronisation and coordination. object-oriented methods offer a promising solution to develop a reusable, maintainable and interoperable SFCS. However, current O-O practices for developing SFCSs are hindered by proprietary representations, which may lead to problems with the portability and interoperability of models. UML, as an industrial standard for O-O notations, has been widely accepted by practitioners to describe static and dynamic parts of a complex system. From the perspective of software engineering, UML offers a variety of standard notations to support the full life-cycle of system development. In this paper, an approach to developing an SFCS using UML through analysis, design and implementation phases is presented, based on the three level hierarchical architecture. An example workstation is studied as an illustration to clarify the proposed approach. In addition to the reusability, portability and maintainability, the presented UML-based development enhances the efficiencies and qualities of SFCS development, considering a wide range of mature tool supports (such as Rational Rose) for UML are available.

关键词： shop floor control system UML object-oriented methods

来源：评论

学校读者我要写书评

暂无评论

Towards measuring object-oriented class stability

引用

IET SOFTWARE 2011年第4期5卷 415-424页

作者： Alshayeb, M. Naji, M. Elish, M. O. Al-Ghamdi, J. King Fahd Univ Petr & Minerals Dept Informat & Comp Sci Dhahran 31261 Saudi Arabia

Stable software, the capability of software to evolve while preserving its design, is an important software feature that software engineers strive for. Stable software tends to reduce maintenance cost and effort. object-oriented (OO) classes form the basic components of the software systems;hence, stable OO classes may contribute to reducing the maintenance and effort cost. The authors identified factors that affect class stability and then used these factors to propose new class stability metric (CSM). Also, the authors theoretically and empirically validated CSM. The results show that the proposed CSM is negatively correlated with the maintenance effort.

关键词： CSM software engineer cost reduction software maintenance Software engineering techniques stable software object oriented class stability software maintenance cost Formal methods object-oriented methods

来源：评论

学校读者我要写书评

暂无评论

Modeling and analysis of message passing in distributed manufacturing systems

引用

IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART C-APPLICATIONS AND REVIEWS 1999年第2期29卷 250-262页

作者： Lin, EYT Zhou, C Univ Maryland Syst Res Inst College Pk MD 20742 USA Georgia Inst Technol Sch Ind & Syst Res Atlanta GA 30332 USA

This paper addresses the information flow between devices and programs in computer integrated manufacturing systems. Specifically, it presents modeling techniques and methods for detecting the existence of message paths among hardware and software components and the upper bound on time delays along that message path. The modeling technique can be used to analyze interoperability between hardware and software components in the system in initial design and specification, The modeling technique has three components: 1) an object model to describe the message passing protocols between communicating components;2) a color timed Petri net to describe the dynamic behavior and state dependency within each individual component;and 3) an object synthesis method that integrates the Petri nets of individual objects and message protocols between objects to describe the dynamics of the entire system. The graphical modeling can enhance communication among different groups involved in system design and the analytical method can provide component specifications. The use of the modeling technique and method in early system design can result in time and cost savings in system integration due to better communication, better component selection and early problem identification.

关键词： delay estimation discrete time systems distributed information systems manufacturing automation object-oriented methods Petri nets reachability analysis real-time systems

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：