• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.843-847
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• 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.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.101-106
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• 2006

The geoidal undulations are needed for determining the orthometric heights from the Global Positioning System GPS-derived ellipsoidal heights. There are several methods for geoidal undulation determination. The paper presents a method employing a simple architecture Two Layer Multiquadric-Biharmonic Artificial Neural Network (TLMB-ANN) to approximate an area of 4200 square kilometres quasigeoid surface with GPS-levelling data. Hardy’s Multiquadric-Biharmonic functions is used as the hidden layer neurons’ activation function and Levenberg-Marquardt algorithm is used to train the artificial neural network. In numerical examples five surfaces were compared: the gravimetric geometry hybrid quasigeoid, Support Vector Machine (SVM) model, Hybrid Fuzzy Neural Network (HFNN) model, Traditional Three Layer Artificial Neural Network (ANN) with tanh activation function and TLMB-ANN surface approximation. The effectiveness of TLMB-ANN surface approximation depends on the number of control points. If the number of well-distributed control points is sufficiently large, the results are similar with those obtained by gravity and geometry hybrid method. Importantly, TLMB-ANN surface approximation model possesses good extrapolation performance with high precision.

• Journal of Information Processing Systems
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• v.6 no.4
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• pp.553-562
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• 2010

The core services in cloud computing environment are SaaS (Software as a Service), Paas (Platform as a Service) and IaaS (Infrastructure as a Service). Among these three core services server virtualization belongs to IaaS and is a service technology to reduce the server maintenance expenses. Normally, the primary purpose of sever virtualization is building and maintaining a new well functioning server rather than using several existing servers, and in improving the various system performances. Often times this presents an issue in that there might be a need to increase expenses in order to build a new server. This study intends to use grid service architecture for a form of server virtualization which utilizes the existing servers rather than introducing a new server. More specifically, the proposed system is to enhance system performance and to reduce the corresponding expenses, by adopting a scheduling algorithm among the distributed servers and the constituents for grid computing thereby supporting the server virtualization service. Furthermore, the proposed server virtualization system will minimize power management by adopting the sleep severs, the subsidized servers and the grid infrastructure. The power maintenance expenses for the sleep servers will be lowered by utilizing the ACPI (Advanced Configuration & Power Interface) standards with the purpose of overcoming the limits of server performance.

• The KIPS Transactions:PartC
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• v.12C no.3 s.99
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• pp.339-346
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• 2005

In recent years, the Grid development focus is transitioning from resources to services, A Grid Service is defined as a Web Service that provides a set of well-defined interfaces and follows specific conventions. SAML as a standard for Web Services which enables exchange of authentication, authorization, and profile information between different entities provides interoperability among different security services in distributed environments. In this paper, we implemented SAML API. By offering interoperability for non XML-based authentication technologies using SAML specification offering a method to integrate the existing Single Sign-On technologies, the API provides convenience for accessing different services in Grid architecture.

• The Transactions of the Korea Information Processing Society
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• v.6 no.9
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• pp.2311-2319
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• 1999

We present two heuristic algorithms for the task allocation problem (NP-complete problem) in parallel computing. The problem is to find an optimal mapping of multiple communicating tasks of a parallel program onto the multiple processing nodes of a distributed-memory multicomputer. The purpose of mapping these tasks into the nodes of the target architecture is the minimization of parallel execution time without sacrificing solution quality. Many heuristic approaches have been employed to obtain satisfactory mapping. Our heuristics are based on genetic algorithms and simulated annealing. We formulate an objective function as a total computational cost for a mapping configuration, and evaluate the performance of our heuristic algorithms. We compare the quality of solutions and times derived by the random, greedy, genetic, and annealing algorithms. Our experimental findings from a simulation study of the allocation algorithms are presented.

• The Transactions of the Korea Information Processing Society
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• v.7 no.2
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• pp.470-476
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• 2000

This paper describes an IP design of a low-power microcontroller using an architecture level design methodology instead of a transistor level. To reduce switching capacitance, the register-toregister data transfer is adopted to frequently used register transfer micro-operations. Also, distributed buffers are proposed to reduce a input data rising edge time. To reduce power consumption without any loss of performance, pipeline processing should be used. In this paper, a 4-stage pipelined datapath being able to process CISC instructions is designed. Designed microcontroller lessens power consumption by 20%. To measure a power consumption, the SYNOPSYS EPIC powermill is used.

• The Transactions of the Korea Information Processing Society
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• v.4 no.8
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• pp.1948-1960
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• 1997

Quality of a new system is closly related to the quality of components in reuse repository. Quality assessment is essential to construct a reuse library. Definition of quality and method of assessment are totally different in reuse environments. User interface, functionality, performance are main factor in non-reuse development environment. However, reuse environment needs more reusability, extensibility, generality, and maintainability in quality assessment. This paper describes a development of quality assessment tool for multimedia object reuse conponents. Tool gets reuse components described by C++ or IDL, and analyses style, structure, coupling, strength, complexity, understandability, etc. Ultimatly the tool generate quality satisfaction degree for reuse programmers. Quality assessment services are supported in distributed object architecture, CORBA.

• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3075-3085
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• 2000

According to distributed, large-caled environment of software development and operation, the elicitation and specivication of correct and complete requrement is the most important factor for the system. In addition contiuous and dramatic systerm canging requests in cooperative environment with internet require more efficient, requirement management. In this paper we detine the specification architecture and techruques for requrements, so that we improve the efficiency ofnatural language-based requirement speciticationand management in a cooperatie work environment. Also, we propose a software requirement engineering process model and environment based on requirements in a CSC@(Computer Supported Cjooperative Work) environment, therefore transfer them into analysis phase.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3027-3029
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• 1999

인간과 함께 협력하는 서어비스 산업에서 요구되는 로봇은 고정된 환경에서 단순 반복 작업을 하는 기존 산업용 로봇의 개념을 뛰어 넘어 변화하는 환경에서 이동하면서 물체 이송 및 조작 기능을 수행하는 작업 형태를 취한다. 일반적으로 서어비스 로봇은 이동 능력과 조작능력이 겸비된 mobile manipulator의 외양을 갖는 것이 가장 응용 분야가 넓다. 이러한 mobile manipulator는 구동 축만 10축 내외가 되므로 축별 서보 제어기와 종류별 센서 제어기들을 분산화 시키는 구조가 신뢰성, 연산 능력의 측면에서 바람직하다. 개방형 구조로써 서보 제어기와 센서 제어기의 결합에 따른 비용 절감을 위하여 저가의 고속 통신망을 사용하고, 제어기 구성 요소들의 수급 다양화와 보수 유지의 간편화를 위하여 개방화된 인터페이스 하드웨어를 채택한다. 또한 자체 동력원에 의해 구동되는 것이 작업범위에 제한을 가하지 않으므로 로봇 제어기가 로봇 내부에 실장되어 오랜 시간 운용 가능하도록 소형화된 구조를 지니도록 설계한다.

• Journal of Electrical Engineering and Technology
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• v.6 no.5
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• pp.605-612
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• 2011

As the power grids are integrated into one big umbrella called a "smart grid," communication protocol plays a key role in successful operations. The successful deployment of smart grid interoperability is a major hurdle that must be overcome. The micro grid, a small power system that distributes energy resource, is operated in diverse regions. Different vendors use different communication protocols in the operation of the micro grid. Recently, the IEC 61850 has been legislated to solve the interoperability problems in power utility automation. The present paper presents a micro grid system based on the IEC 61850 protocol. It consists of a micro grid monitoring system, a protocol converter that transforms serial data to IEC 61850 data, and distributed energy resource controllers for diverse DER nodes. A developed communication gateway can be deployed for DER controllers with serial links to exchange data with IEC 61850-based devices. The gateway can be extended to IEC 61850-based distribution automation systems, substation automation systems, or SCADA.