• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.561-562
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• 2015

2013년 이후, 한국전력공사에서는 신규건설 변전소로 디지털변전소(Digital Substation)를 건설하고 있다. 디지털변전소 내에는 서버(IED, 지능형전자장치), 클라이언트(상위운영시스템)가 필수요소들이며, 이 둘은 서로 서버/클라이언트 통신 서비스를 수행하고 있고 IEC61850 기반으로 하고 있다. 바뀐 정책과 프로토콜 때문에 사용되는 기기 역시 기존 디지털 보호 계전기에서 IED로 성능이 변화하였고, 기존에 수행하던 보호성능검증 방법인 동특성시험 역시 IEC61850 기반 통신서비스 성능도 함께 보아야 한다는 관점에서 본 연구가 시작되었다. 본 논문에서는 RTDS를 이용한 IEC 61850 기반 IED 동특성 시험 성능검증 방법에 대하여 살펴보고, 그 결과를 알아보고자 한다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.118-120
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• 2003

컴포넌트 기반 개발 방법은 조립 가능한 컴포넌트들을 이용하여 소프트웨어를 구현하는 기술로써, 소프트웨어의 생산성 및 품질을 높이는 효과적인 방법으로 알려져 있다. 향후 성장이 예상되는 컴포넌트 시장에서는 여러 컴포넌트 공급자들에 의해 COTS나 Web Services의 형태로 동일 내지는 유사 기능을 수행하는 대체 가능한 컴포넌트들이 나타나게 될 것이다. 개발되는 컴포넌트 기반 소프트웨어의 품질을 위해서는 여러 경쟁 컴포넌트들 중에서 우수한 성능을 가진 컴포넌트를 선택하는 기술이 중요한 요소의 하나라고 할 수 있다. 일반적으로 컴포넌트는 컴포넌트 모델에 종속적이기 때문에 컴포넌트의 성능 측정기도 측정 대상 컴포넌트뿐만 아니라 컴포넌트 모델에 종속적으로 구현된다. 본 논문은 컴포넌트 모델과 미들웨어 프레임워크에 중립적인 분산 컴포넌트의 성능 측정 모델에 대하여 설명한다. 이 모델을 이용하여 컴포넌트 모델에 중립 적인 성능측정기를 개발할 수 있으며 컴포넌트의 비교와 검증에 필요한 객관적인 성능 측정 결과를 얻을 수 있다.

• Annual Conference of KIPS
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• 2020.11a
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• pp.810-813
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• 2020

자연어처리 분야에서 딥러닝 기반의 분류 모델은 획기적인 성능을 보여주고 있다. 특히 2018 년 발표된 구글의 BERT 는 다양한 태스크에서 높은 성능을 보여준다. 본 논문에서는 이러한 BERT 가 클래스 불균형이 심한 데이터에 대해 어느 정도 성능을 보여주는지 확인하고 이를 해결하는 방법으로 EDA 를 선택해 성능을 개선하고자 한다. BERT 에 알맞게 적용하기 위해 다양한 방법으로 EDA 를 구현했고 이에 대한 성능을 평가하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.125-126
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• 2014

현재의 안전설비기준은 정량적 관점에서 정의되었고, 선박 재난 시나리오에 관한 대응수준을 평가할 방법이 없다. 선박, 특히 여객선 승객의 안전성을 향상시키기 위해서는 설계단계 혹은 증개축단계에서 성능기반의 피난안전설계에 의한 평가를 통해 문제점을 파악하고 개선안을 제실할 필요가 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.253-255
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• 2001

본 논문에서는 비디오 데이터가 지니는 움직임 객체의 움직임 경로(Moving Objects'Trajectories)를 이용한 사용자 질의에 대해 효율적인 검색을 위만 새로운 시그니쳐 기반 접근 기법을 제안한다. 제안하는 시그니쳐 기반 접근 기법은 데이터 파일을 직접 접근하기 전에 전체 시그니쳐들을 탐색하여 필터링을 수행하기 때문에, 순차 탐색에 대해 디스크 접근 횟수를 감소시켜 검색 성능을 향상시킨다. 마지막으로 성능 평가를 통해 제안하는 방법이 삽입 시간, 검색 시간, 그리고 부가 저장 공간의 검색 효율(Retrieval Efficiency) 측면에서 성능이 우수함을 보인다.

• Journal of KIISE:Software and Applications
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• v.31 no.8
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• pp.1043-1053
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• 2004

The performance of a component can significantly influence the overall performance of the system being developed in the component based software development. Existing performance measurement tools for components are often built specific to the component model or middleware. One disadvantage of this approach is that when the system is moved to a new platform during the life-cycle of the system, the measurement tools also need to be adapted. A similar problem is observed when components built for different platforms are integrated with a new integration technology like Web Services. This paper presents a new model for measuring component performances, which is independent of particular component models or middleware. This method presents a interoperability for each performance data by model transformation process from middleware independent performance measuring models to middleware dependent performance measuring models. Our model allows objective performance data to be obtained that can be used to compare performances of components based on different component models or middleware platforms.

• Journal of KIISE:Databases
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• v.36 no.5
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• pp.374-385
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• 2009

Flash memory becomes increasingly popular as data storage for various devices because of its versatile features such as non-volatility, light weight, low power consumption, and shock resistance. Flash memory, however, has some distinct characteristics that make today's disk-based database technology unsuitable, such as no in-place update and the asymmetric speed of read and write operations. As a result, most traditional disk-based database systems may not provide the best attainable performance on flash memory. To maximize the database performance on flash memory, some approaches have been proposed where only the changes made to the database, i.e., logs, are written to another empty place that has born erased in advance. In this paper, we propose an efficient log management scheme for flash-based database systems. Unlike the previous approaches, the proposed approach stores logs in specially allocated blocks, called log blocks. By evenly distributing logs across log blocks, the proposed approach can significantly reduce the number of write and erase operations. Our performance evaluation shows that the proposed approaches can improve the overall system performance by reducing the number of write and erase operation compared to the previous ones.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.1
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• pp.9-22
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• 2022

Virtual Reality(VR) technology is an interface technology that is actively used in various audio-visual-based applications by showing users a virtual world composed of computer graphics. Since VR-based applications are graphic processing-based applications, expensive computing devices equipped with Graphics Processing Unit(GPU) are essential for graphic processing. This incurs a cost burden on VR application users for maintaining and managing computing devices, and as one of the solutions to this, a method of operating services in cloud environments is being used. This paper proposes a performance management technique to address the problem of performance interference between containers owing to GPU resource competition in container-based high-performance cloud environments in which multiple containers share a single GPU. The proposed technique reduces performance deviation due to performance interference, helping provide uniform performance-based remote VR services for users. In addition, this paper verifies the efficiency of the proposed technique through experiments.

• The Journal of Korean Association of Computer Education
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• v.14 no.4
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• pp.63-70
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• 2011

Recommender systems, which predict and recommend items that may possibly draw users' interests, have been applied in various fields as e-commerce systems are widespread. Collaborative filtering, one of the major methodologies of recommender systems, recommends either items similar to those preferred by the user, or items preferred by the other similar user. Therefore, two problems determine its performance; one is correct estimation of similarity and the other is predicting the real rating of the recommended item. This study addresses the latter problem. Previous studies predict the real rating based on the mean of the ratings, but this study proposes a prediction based on the range of the ratings and investigates its performance through experiments. As a result, it is demonstrated that the proposed method improves the mean absolute error significantly, compared to the previous method.

• Journal of the Korean Society for information Management
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• v.21 no.4 s.54
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• pp.133-152
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• 2004

As the Internet facilitates the rapid increase of information availability, the study on SDI service that provides users with relevant document in a timely manner has been developed. However, the practical use of this service has been low. This thesis aims at analyzing the reasons for this and developing relevance feedback based SDI system to improve the performance of the existing SDI system. Experimental systems that are developed for this study are SDI system based on users' minimum intervention feedback, SDI system based on perfect automation feedback, and SDI system based on users' maximum intervention feedback. The fourth system that utilizes the traditional SDI system is also studied to evaluate the level of performance improvement of the newly developed three types of SDI system. As a result of this study, SDI system based on users' maximum intervention feedback showed greatest performance improvement. The next performance improvement happened in order of SDI system based on perfect automation feedback, SDI system based on users' minimum intervention feedback, and the traditional SDI system. Feedback based systems showed greater performance improvement as they went through more feedback processes.