• 전기학회논문지
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• 제62권9호
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• pp.1209-1216
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• 2013

Recently, there is a rising interest in smart grid operating system which manages various types of distributed generation, smart meters, and electric vehicles with power grid. Considering the features of smart grid environment, the interoperability should be one of the important factors to build smart grid environment successfully. To secure interoperability, smart grid operating system should conform to some standards in terms of the data representation and communication. CIM and OPC-UA are the international standards widely used in smart grid domain for enabling interoperability. They provide common information model and the unified architecture for communicating between each systems or applications. In this paper, we illustrate a smart grid operating system that we have developed to secure interoperability between not only applications but also numerous legacy systems(applications) by implementing CIM based information model and OPC-UA based communication interface services.

• 대한전기학회논문지:전력기술부문A
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• 제51권11호
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• pp.535-543
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• 2002

Modern power grids are becoming more and more stressed with the load demands increasing continually. Therefore large stressed power systems exhibit complicated dynamic behavior when subjected to small disturbance. Especially, it is needed to analyze special conditions which make small signal stability structure varied according to operating conditions. This paper shows that the relation between small signal stability structure varied according to operating conditions. This paper shows that the relation between small signal stability and operating conditions can be identified well using node-focus point and 1:1 resonance point. Also, the weak point which limits operating range is found by the analysis of resonance condition, and it is shown that reactive power compensation may solve the problem in the weak points. The proposed method is applied to test systems, and the results illustrate its capabilities.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 1999년도 춘계학술대회 발표논문집
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• pp.145-153
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• 1999

We consider a Direct Input Output Manufacturing System(DIOMS) which has a munber of machine centers placed along a built-in Automated Storage/Retrieval System(AS/RS). The Storage/Retrieval (S/R) machine handles parts placed on pallets for the machine centers located at either one or both sides of the As/Rs. This report studies the operational aspect of DIOMS and determines the optimal operating policy by combining computer simulation and genetic algorithm. The operational problem includes: input sequencing control, dispatching rule of the S/R machine, machine center-based part type selection rule, and storage assignment policy. For each operating policy, several different policies are considered based on the known research results. In this report, using the computer simulation and genetic algorithm we suggest a method which gives the optimal configuration of operating policies within reasonable computation time.

• 대한임베디드공학회논문지
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• 제11권6호
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• pp.335-341
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• 2016

As information technology advances rapidly, various smart devices are becoming an essential element in our lives. Smart devices are providing services to users through applications up on the operating system. Operating systems have a variety of rules, such as scheduling applications and controlling hardwares. Among those rules, it is significant to protect private information in the information-oriented society. Therefore, isolation task, that makes certain memory space separated for each application, should highly be guaranteed. However, modern operating system offers the function to access the memory space from other applications for the sake of debugging. If this ability is misused, private information can be leaked or modified. Even though the access authority to memory is strictly managed, there exist cases found exploited. In this paper, we analyze the problems of the function provided in the Android environment that is the most popular and opened operating system. Also, we discuss how to avoid such kind of problems and verify with experiments.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제5권3호
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• pp.263-267
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• 2005

Building classifiers for financial real-world classification problems is often plagued by severely overlapping and highly skewed class distribution. New performance measures such as receiver operating characteristic (ROC) curve and area under ROC curve (AUC) have been recently introduced in evaluating and building classifiers for those kind of problems. They are, however, in-effective to evaluation of classifier's discrimination performance in a particular class of the classification problems that interests lie in only a local operating range of the classifier, In this paper, a new method is proposed that enables us to directly improve classifier's discrimination performance at a desired local operating range by defining and optimizing a partial area under ROC curve or domain-specific curve, which is difficult to achieve with conventional classification accuracy based learning methods. The effectiveness of the proposed approach is demonstrated in terms of fraud detection capability in a real-world fraud detection problem compared with the MSE-based approach.

• 한국정보통신학회논문지
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• 제7권8호
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• pp.1831-1839
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• 2003

본 논문은 능동 네트워크를 동작하게 해주는 핵심 모듈인 Enode 노드 운영체제 구조 및 세부 기능들의 내용을 정의한다. 본 논문에서 제안하는 Enode 노드 운영체제는 능동 네트워크 환경에 적합하도록 설계하였다. 또한 "실행 환경"(Execution Environment : EE)에서 편리하게 사용할 수 있도록 인터페이스를 설계하였다. 본 논문에서 제안하는 Enode 노드 운영체제는 도메인을 중심으로 핵심적인 기능 설계에 주력하였다. Enode 운영체제는 Linux 운영체제 상에서 설계되었다. 또한 본 논문에서 제안하는 Enode 노드 운영체제의 인터페이스에 대한 실험을 수행하였다.

• 한국도서관정보학회지
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• 제15권
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• pp.207-243
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• 1988

This study is an attempt to furnish some helpful data for the maximum use of online information retrieval systems based on the comparative analysis of commands and operating terms employed by DIALOG, ORBIT and BRS which are three largest information retrieval systems in the world. To begin with, the historical development, service contents and retrieval functions of three systems were overviewed in the second chapter, on the basis of which the concrete functions and contents of the commands and the operating terms of the three systems were compared and analyzed one another. Commands were explained divided into basic and special ones. The basic commands subdivided into 44 items were put into the form of a diagram(Table 1). The special commands were first subdivided into search commnad, output-related commands and su n.0, pplementary commands, and then 14 items of which were comparatively analyzed and were represented as a chart(Table 2). In addition, any stand-alone commands employed by each system were also analyzed as a chart(Table 3). The Operating terms other than commands were subdivided into 16 items and were represented as a chart(Table 4). Password, inverted file, search step number in search session, etc were explained to the very detailed extent. A self-evident, single word is that the through understanding of commands is essential to the maximm use of all the functions of each of three systems.

• 한국주거학회논문집
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• 제23권2호
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• pp.99-106
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• 2012

Compared to Packaged Terminal Air Conditioning Systems, Radiant Cooling Systems have the advantage of energy saving and thermal comfort. Thermally Activated Building System (TABS) is one of the radiant heating and cooling systems. The main difference between TABS and other radiant systems lies in the usage of the time-lag effect of storing heat energy in the concrete. Current energy usage in summer time is concentrated within a specific time by using Packaged Terminal Air-Conditioner (PTAC). Due to the time-lag effect of TABS, energy usage can be distributed to other time zones. To maximize this effect, it is important to determine the appropriate operating mode, which for TABS is dependent upon the cooling load generated by the occupancy schedule. In this study, occupancy schedules are determined for various residential types. The operating modes of TABS for these residential types are estimated by using a dynamic computational simulation method. The results indicate that the operating modes of TABS can be determined by residential type and occupancy schedule. The load handled ratio by TABS is set up differently according to the cooling load profile obtained from residential type and occupancy schedule. By using TABS, energy consumption could be reduced by 20% compared to PTAC.

• 정보와 통신
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• 제11권6호
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• pp.37-54
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• 1994

멀티미디어 기술의 획기적 발전으로 이를 응용한 다양한 서비스가 개발되고 있다. 본 논문에서는 멀티미디어 응용 서비스를 TV, 컴퓨터, 통신, 주변기기, 소프트웨어 계열로 분류하고 설명하였다. 이중 컴퓨터 부분에서 멀티미디어 서비스를 중점적으로 설명하며 이러한 서비스가 제공되기 위한 시스템의 주요 서브시스템으로서 멀티미디어 데이터 처리를 위한 초고속 통신망, 운영체제, 지능형 에이젼트에 대한 논의를 하였다. 이중 특히 멀티미디어 운영체제 기술은 종합 멀티미디어 서비스 제공을 위한 하부 구조로서 최근 가장 활발히 발전되고 잇는 분야이다. 이에 본 논문에서는 일반적인 멀티미디어 운영체제의 발전방향 및 현재 개발 완료된 COSMOS 멀티미디어 그룹표현용 운영체제에 관한 설명을 한다. COSMOS의 특성, 모델, 추상적 데이터 구조에 관한 논의와 더불어 COSMOS상에서 개발된 3자간 영상회의시스템의 성능분석을 통하여 COSMOS와 같은 운영체제를 통한 멀티미디어 운영체제의 제공이 멀티미디어 서비스 환경변화를 주도함을 설명하였다.

• 전자통신동향분석
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• 제32권6호
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• pp.83-95
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• 2017

The trend of manycore hardware has recently evolved more quickly than expected. However, an operating system, which is software used for managing computer resources, is still optimized for a multicore system. To handle this issue, we started a research project called 'Research on High Performance and Scalable Manycore Operating Systems' in 2014. This article briefly examines the technology trends of manycore hardware and operating systems, and introduces the research areas and outcomes during the first stage of the project(2014-2017). The core technologies improving the performance scalability of manycore systems are publicly available, and anyone can use the source code or apply the ideas of the core technique to other research activities. In addition, the research plans of the second stage of the project(2018-2021) are also included.