• 한국인터넷방송통신학회논문지
• /
• 제11권6호
• /
• pp.275-282
• /
• 2011

현재, UPnP, Jini, SLP와 같은 서비스 디스커버리 프로토콜은 서비스의 표현과 기술, 그리고 메시지 교환 패턴과 같은 기본적인 서비스 디스커버리 기능만 제공한다. 이것은 서비스 디스커버리 프로토콜 사이에 서비스의 상호운영성을 저해하는 요소로 작용한다. 따라서, 본 논문에서는 이기종 서비스간의 상호운영성을 높일 수 있도록 CLAM (Component-based Autonomic Layered Middleware) 에이전트 플랫폼을 구성하고, 플랫폼 내의 DF (Directory Facilitator)의 기능을 확장하여 효율적인 서비스가 가능하도록 DF 에이전트를 설계하고 구현한다. 또한 DF 에이전트에서 확장성과 상호운영성을 보장하기 위해 DHT-Chord 알고리즘을 이용한 효율적인 서비스 디스커버리 메커니즘을 제안한다.

• 한국CDE학회논문집
• /
• 제4권4호
• /
• pp.371-380
• /
• 1999

This study proposes a process information model which can integrate various activities during the product development process, the system which can manage the process. Development process information will allow designers and managers to access previous tasks readily and utilize the information in making decisions at hand. While developing products in heterogeneous and distributed environments, concurrent and collaborative designs can be achieved by STEP. The process model in this study divides the task of product development into two fundamental parts, Specific Process(SP) and Normal Process(NP). SP includes the specific information and refer to those defined by prior STEP. NP is routine process excluded from being defined as SP. Due data information can be added to manage development pace and to show delayed tasks. As two or more different processes can be linked to show the entire development flow, Static STEP information can be dynamically interlaced. Remote location operations can be incorporated on the Internet using STEP, and information can be shared. The system has been built upon a process model schema so that task stage, design history, and different development style can be managed and accessed for each component. The system has been proven efficient in information management and exchange by several scenario testings.

• Journal of Power Electronics
• /
• 제16권2호
• /
• pp.553-563
• /
• 2016

This paper presents a digital hardware implementation of a real-time simulator for a multiphase drive using a field-programmable gate array (FPGA) device. The simulator was developed with a modular and hierarchical design using very high-speed integrated circuit hardware description language (VHDL). Hence, this simulator is flexible and portable. A state-space representation model suitable for FPGA implementations was proposed for a dual three-phase induction machine (DTPIM). The simulator also models a two-level 12-pulse insulated-gate bipolar transistor (IGBT)-based voltage-source converter (VSC), a pulse-width modulation scheme, and a measurement system. Real-time simulation outputs (stator currents and rotor speed) were validated under steady-state and transient conditions using as reference an experimental test bench based on a DTPIM with 15 kW-rated power. The accuracy of the proposed digital hardware implementation was evaluated according to the simulation and experimental results. Finally, statistical performance parameters were provided to analyze the efficiency of the proposed DTPIM hardware implementation method.

• 인터넷정보학회논문지
• /
• 제3권2호
• /
• pp.39-56
• /
• 2002

데이터베이스를 사용하여 분산된 환경에서 많은 응용이 구축되어감에 따라 지역 데이터베이스의 자치성은 유지하면서 데이터베이스들을 상호 공유하는 데이터웨어하우징, 데이터마이닝 등의 응용이 많이 늘고 있다. 이러한 응용의 첫 번째 요구사항은 이질의 데이터베이스 스키마 통합이다. 기존의 데이터베이스 스키마 통합은 통합을 위한 스키마 공통 모델의 부재, 스키마 통합 프로그램의 복잡성으로 어려움을 겪어 왔다. 본 연구는 XML Schema를 데이터베이스 스키마 통합을 위한 공통된 데이터모델로 사용하여 데이터 모델을 표준화하고, 스키마 통합을 위한 연산들을 정의하여 이를 XSLT로 대응시킴으로써 스키마 통합 자동화 프로그래밍의 복잡성을 해결하며, 스키마 충돌 유형에 따라 통합하는 방법을 제시하였다. 제시된 방법은 기존의 통합 모델에 비하여 표준화, 확장성 등의 장점을 갖는다.

• 한국컴퓨터정보학회논문지
• /
• 제5권2호
• /
• pp.37-42
• /
• 2000

CORBA에서 객체 기술은 분산 및 이기종 기계에 분산되어 있는 소프트웨어 컴포넌트의 통합된 구현을 용이하게 한다. CORBA와 유사한 객체 통합 기술들은 표준화된 컴포넌트 통합 및 상호 동작 모델을 정하고 호환 불가능한 컴포넌트 구현을 캡슐 화하기 위한 객체지향 원리를 발전시켰다 본 논문에서는 Java Bean에 기반을 둔 분산 시스템 환경에서 객체와 객체간에 관련성을 모델링하기 위해 컴포넌트, 연결자 및 컴포넌트 스키마로 구성된 구조화된 모델을 제시하고 구현한다. 특히 Java Bean 환경에서 객체간의 관련성을 모델링하기 위한 연결자의 구성에 중점을 둔다.

• 한국CDE학회논문집
• /
• 제12권4호
• /
• pp.308-320
• /
• 2007

A multi-agent and web based engineering framework concerning the automation of fatigue durability analysis for welded bogie frame of railway vehicles is presented. Mostly, this kind of design or analysis includes complex workflow, huge amounts of information processing, and problem solving. Macro programs of I-DEAS, APDL of ANSYS, and in-house fatigue code are utilized for parametric geometry representation, automatic mesh generation, static stress analysis, fatigue durability analysis, post-processing, and data sorting. The engineering framework is implemented on the JADE. Since every task requires a fairly complex process and specialized knowledge, the multi-agent based framework is very useful to keep the independency among several disciplines or tasks and to use distributed hardware and software resources. All engineering programs are integrated by XML wrapper. Related database of the engineering framework and web based user interfaces are also developed. A parametric study is carried out to take into account the effect of geometrical change of transom support bracket on its cumulative fatigue damage. The developed engineering framework reduced remarkably the time and costs required in designing and solving engineering problems.

• 한국전자거래학회지
• /
• 제10권4호
• /
• pp.19-33
• /
• 2005

본 연구에서는 시맨틱 웹을 구성할 수 있도록 하는 지식표현, 온톨로지, 에이전트를 통해 급변하는 전자거래 환경을 극복하고 이질적이고 분산되어 있는 정보들을 통합할 수 있도록 하기 위한 방법론을 제시하고자 한다. 이를 위해 모델링의 기반이 되는 구문론적/의미론적 통합 및 에이전트의 운용방법론에 대해 논하며, 메타 모델링에 바탕을 두는 온톨로지의 구축에 중점을 두고 설명한다. IRDS (Information Resource Dictionary Standard) 프레임워크에 기반한 구조에 따라 OWL(Web Ontology Language)을 사용하여 온톨로지를 구체화하며, 프로세스 표현을 위해 PSL(Process Specification Language)-ontology의 용어들을 중간 계층으로 구성하여 차용한 예를 제시한다. 제시한 프레임워크를 통해 정보 자원들과 비즈니스 프로세스를 정의하고 공유하며 관리함으로써 중복성과 불일치성을 제거할 수 있을 것이다.

• 산업경영시스템학회지
• /
• 제32권4호
• /
• pp.169-177
• /
• 2009

Concurrent Engineering (CE) has presented new possibilities for successful product development by incorporating various product life-cycle functions from the earlier stage of design. In the product design, geometric representation is vital not only in its traditional role as a means of communicating design information but also in its role as a means of externalizing designer's thought process by visualizing the design product. During the last dozens of years, there has been extraordinary development of computer-aided tools intended to generate, present or communicate 3D models. However, there has not been comparable progress in the development of 3D-CAD systems intended to represent and manipulate a variety of product life-cycle information in a consistent manner. In the previous research, the authors proposed a novel concept called Minus Volume (MV) to incorporate various design information relevant to product life-cycle functions. This paper proposes the use of the MV concept for the collaborative design environment, where many team members are geographically distributed over the networked environment, including Internet, Intranet, WWW, etc. A prototype 3D-CAD system is implemented based on the MV concept and illustrated with the successful implementation of collaborative design example.

• Advances in materials Research
• /
• 제5권2호
• /
• pp.107-120
• /
• 2016

The static analysis of the simply supported functionally graded plate under transverse load by using a new sinusoidal shear deformation theory based on the neutral surface concept is investigated analytically in the present paper. No transversal shear correction factors are needed because a correct representation of the transversal shearing strain is given. The mechanical properties of the FGM plate are assumed to vary continuously through the thickness according to a power law formulation except Poisson's ratio, which is kept constant. The equilibrium and stability equations are derived by employing the principle of virtual work. Results are provided for thick to thin plates and for different values of the gradient index k, which subjected to sinusoidal or uniformly distributed lateral loads. The accuracy of the present results is verified by comparing it with finite element solution. From the obtained results, it can be concluded that the proposed theory is accurate and efficient in predicting the displacements and stresses of functionally graded plates.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2005년도 춘계종합학술대회
• /
• pp.843-847
• /
• 2005

The development of distributed application in the standardized CORBA(Common Object Request Broker Architecture) environments reduces the developing time and maintaining cost of the systems. Because of these advantages, the development of application is being progressed in the several fields using the CORBA environments. The programmers in the CORBA environments usually develop the application programs using the CORBA IDL(Interface Definition Language). The IDL files are compiled by IDL compiler and translated into the stubs and skeleton codes which are mapped onto particular target language. The stubs produced by IDL compilers processes the marshaling a data into message buffer. Before a stub can marshal a data into its message buffer, the stub must ensure that the buffer has at least enough free space to contain the encoded representation of the data. But, the stubs produced by typical IDL compilers check the amount of free buffer space before every atomic data is marshaled, and if necessary, expand the message buffer. These repeated tests are wasteful and incidence of overheads, especially if the marshal buffer space must be continually expanded. Thus, the performance of the application program may be poor. In this paper, we suggest the way that the stub code is maintain the enough free space before marshaling the data into message buffer. This methods were analyzes the overall storage requirements of every message that will be exchanged between client and server. For these analysis, in the Front End of compiler has maintain the information that the storage requirements and alignment constraints for data types. Thus, stub code is optimized and the performance of application program is increased.