• The KIPS Transactions:PartA
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• v.15A no.3
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• pp.167-180
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• 2008

Consolidating servers into a virtualized system increases entire system utilization, while suffers from performance degradation due to the additional virtualization layer. In this paper, we proposed a performance evaluation methodology for comparing virtualized systems with native non-virtualized systems. We defined a system waste rate per consolidated throughput as a metric, and described the method for calculating system waste rate and consolidated throughput for both of virtualized systems and non-virtualized systems. Using the proposing performance evaluation methodology, we established testbeds, evaluated their performance, and compared the metrics of both systems. As a result of the evaluation, we could show the appropriateness of our methodology and analyze the effect of the application characteristics.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.709-711
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• 1998

범 구조적 병렬 컴퓨팅 모델인 린다 모델의 비결합성, 확장성, 부하균등, 동기화 문제 해결과 같은 많은 특성을 가지고 있는 반면, 튜플 스페이스로의 메시지 집중 현상으로 전체 시스템의 성능을 저하시키는 결정적인 문제를 안고 있다. 따라서 본 논문에서는 계층적 튜플 스페이스를 제공함으로써 기존 린다 모델의 장점을 모두 수용함과 동시에 메시지 집중 현상을 줄일 수 잇는 계층적 튜플 스페이스 린다 몰델을 제안한다. 또한 RP층적 튜플 스페이스를 구성하기 위한 병렬 코드 생성 방법을 모색하고, 그 과정에서 분석결과 및 프로그램성능 분석을 통해 실제 시스템에 균등하게 사상함으로써 전체적인 프로세서의 효율적인 수행을 가능하게 하는 사상 기법을 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06b
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• pp.193-196
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• 2011

공간적으로 다양하게 재구성되며 이동하는 분산/이동/실시간 시스템을 명세 및 분석하기 위한 기존의 프로세스 대수들은 명세/분석 과정에서 텍스트 기반의 명세 언어를 사용한다. 이로 인하여 프로세스 사이의 이동성과 프로세스들의 공간적 분포를 대한 명세 및 분석 방법은 매우 큰 복잡도가 존재한다. 이를 극복하기 위하여 일반 프로세스 대수를 시각적인 형태로 표현하는 다양한 기법들이 제안되었다. 이러한 시각화 언어들은 시스템의 특정 상태를 명세하거나, 시스템의 속성을 공간적 분포와 링크정보로 분리하는 방법들이 사용되었지만, 명세하고자 하는 시스템의 전체 행위에 대한 효율적인 명세 방법이 존재하지 않고, 시각화 언어임에도 불구하고 텍스트기반의 프로세스 대수와 병행되어 사용되어야만 하는 제약들이 존재한다. 이러한 제약들을 극복하기 위한 하나의 방법으로 본 논문에서는 프로세스 대수를 위한 새로운 시각화 언어인 Onion Visual Language를 제안한다. Onion Visual Language는 프로세스 사이에서 발생하는 이동과 상호작용 등의 전체 행위를 원형의 양파껍질과 같은 형태로 표현하며, 각 프로세스들 사이에서 발생하는 행위들의 관계를 액션으로 표현한다. 또한, 계층화된 프로세스 구조, 프로세스의 상태정보, 프로세스의 미래 행위 정보, 비결정적 행위정보를 포함하여 매우 복잡한 시스템의 특징을 효율적으로 명세/분석 가능하도록 하였다.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.4
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• pp.213-225
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• 2007

Flash memory is widely used as a storage device for potable equipments such as digital cameras, MP3 players and cellular phones because of its characteristics such as its large volume and nonvolatile feature, low power consumption, and good performance. However, a block in flash memories should be erased to write because of its hardware characteristic which is called as erase-before-write architecture. The erase operation is much slower than read or write operations. FTL is used to overcome this problem. We compared the performance of the existing FTL algorithms on Windows-based OS. We have developed a tool called FTL APAT in order to gather I/O patterns of the disk and analyze the performance of the FTL algorithms. It is the log buffer scheme with full associative sector translation(FAST) that the performance is best.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.1
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• pp.107-120
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• 2020

This study aims to analyze the importance of key elements and clauses of the preliminary ethical guideline for Automated Vehicles(AV) using the Analytic Hierarchy Process(AHP). Reflecting previous researches on AV ethical guideline, we developed the questionnaire for the AHP survey. According to the AHP results of key elements and detailed clauses, Protecting human dignity and life are most important as a top priority in overall clauses. Also, clauses related to the user's liability are high priorities, but clauses related to the administrator's liability are low priorities. These results implied that the government should enact a law and draw up an ethical guideline in a neutral attitude to respect the private areas and enjoy the public interests. In order to declare Korean ethical guidelines and improve social acceptance, it is necessary to conduct a seminar and make an educational program, also gather the opinions of citizens and experts.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.192-207
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• 2023

Commercialization of level-4 (Lv.4) autonomous driving applications requires the definition of a safe road environment under which autonomous vehicles can operate safely. Thus, a risk assessment model is required to determine whether the operation of autonomous vehicles can provide safety to is sufficiently prepared for future real-life traffic problems. Although the risk factors of autonomous vehicles were selected and graded, the decision-making method was applied as qualitative data using a survey of experts in the field of autonomous driving due to the cause of the accident and difficulty in obtaining autonomous driving data. The fuzzy linguistic representation of decision-makers and the fuzzy analytic hierarchy process (AHP), which converts uncertainty into quantitative figures, were implemented to compensate for the AHP shortcomings of the multi-standard decision-making technique. Through the process of deriving the weights of the upper and lower attributes, the road alignment, which is a physical infrastructure, was analyzed as the most important risk factor in the operation risk of autonomous vehicles. In addition, the operation risk of autonomous vehicles was derived through the example of the risk of operating autonomous vehicles for the 5 areas to be evaluated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.391-395
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• 2009

최근 한정된 자원으로 인한 에너지 수요가 증가하면서 에너지 절약 문제가 중요한 과제로 대두되었다. 본 논문에서는 효율적인 에너지 절약 문제를 해결하기 위한 방법으로 열 영상과 퍼지 제어 기법을 적용하여 실내 냉방 장치의 풍향과 풍속을 제어하는 방법을 제시한다. 본 논문에서는 실내 냉방 장치의 풍향과 풍속을 제어하기 위해 획득한 초기 열 영상을 색상 분포 영상으로 변환한다. 색상 분포 영상은 Red, Magenta, Yellow, Green, Sky, Blue의 온도 값을 가지는 RGB 값이며 각 색상은 $24.0^{\circ}C$에서 $27.0^{\circ}C$의 분포의 온도 값을 가진다. 본 논문에서는 색상 분포 영상을 좌에서 우로 5개의 계층 구간으로 분류하여 온도를 분석한다. 실내 공간의 색상 분포 영상을 분석하여 얻어진 각 계층 구간의 온도와 대기 중의 습도를 퍼지 소속 함수에 적용하여 구해진 결과 값을 비퍼지화 하고 최종적으로 풍향의 세기를 제어한다. 그리고 열 영상을 분석하여 풍향의 우선순위, 풍향의 지속시간을 결정한다. 제안된 방법을 $300{\times}400$ 크기의 열 영상을 대상으로 기존의 시스템과의 전력량 차이를 시뮬레이션 한 결과, 제안된 방법이 효과적인 것을 확인할 수 있었다.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.201-208
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• 2011

When designing a river, it is important to select the appropriate bank revetment methods, but there are no specific guidelines until now. Accordingly, it is important to prevent over-budgeting by deciding the suitability of the adopted bank revetment methods when designing a river. In this study, an assessment method was developed to assess the suitability of the adopted bank revetment methods when designing a river. By adopting this method to eight rivers, its validity was examined. Analytic Hierarchy Process (AHP) was used for the assessment, along with suitability index (SI) of the adopted bank revetment methods when designing a river. In order to select the best bank revetment methods, all environmental variables of the selected location have to be considered. Accordingly, to assess the designed bank revetment methods, all variables of the selected location have to be considered. The assessing items include hydraulic stability, environmental-ecological feasibility, economy, and amenity of the bank revetment. Each item includes four to five sub-items, and each sub-items reflect survey results on the locations. The assessment method was adopted and assessed for eight rivers, and bank revetments was designed to determine the SI. The result of this study is considered to be appropriate when assessing an eco-friendly bank revetment methods, and inappropriate designed bank revetments will guide future planners for selecting the most appropriate construction method.

• The Transactions of the Korea Information Processing Society
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• v.5 no.1
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• pp.86-96
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• 1998

The class hierarchy structure in an object-oriented design model is effective to the software reusabilily and lhe design of complex syslem. This paper suggests lhe objecl-orienled class hierarchy structure design melhod using lhe rapid prololyping lechniques. In this method, relationship recognition and similarity are estimated by the new class classification in object modeling level. Then lhe estimation of aUribute and method in class is needed. Each design module such as class hierarchy struclure which is generaled wilh inleractive and repealed work consisls of reference relationship, inheritance relationship and composite relationship. These information are slored in lhe table to maintenance lhe program and implementation, the class relationship is represented with graph and the node class is iconized. This method is effective in reslructuring of class hierarchy are reusing of design information, because of addition of new class and deletion with ease. The efficiency of syslem analysis, design and implementation is enhanced by converting into prololype system and real system.

• The Korean Journal of Applied Statistics
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• v.24 no.6
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• pp.1077-1094
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• 2011

We accomplish clustering analyses for yeast cell cycle microarray expression data. To reflect the characteristics of a time-course data, we screen the genes using the test statistics with Fourier coefficients applying a FDR procedure. We compare the results done by model-based clustering, K-means, PAM, SOM, hierarchical Ward method and Fuzzy method with the yeast data. As the validity measure for clustering results, connectivity, Dunn index and silhouette values are computed and compared. A biological interpretation with GO analysis is also included.