• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2008년도 추계학술대회 및 정기총회
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• pp.353-358
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• 2008

The ocean has settled down in human mind as a territory and a leisure space from which anyone enjoys and takes a benefit under the national sovereignty, as the new era of Sea comes. In addition, because the population engaged in marine activities has rapidly increased, the number of marine accidents consequently has grown up as well. In this reason, currently it has been highlighted to devise safety measures to prevent large scale accidents or disasters on the oceans. Therefore, this thesis firstly points out issues and problems of current search and rescue operations, and secondly studies three primary factors of the search and rescue operations, which are decision of search range, decision of search asset, and decision of search duration. Finally, the thesis suggests a theoretical foundation of the search and rescue operations by applying the result of studies and the marine search theory through a theoretical approach to reasonable standards.

• 한국컴퓨터정보학회논문지
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• 제23권3호
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• pp.1-8
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• 2018

In this paper, we propose a new page replacement policy using recency and frequency on hybrid main memory. The proposal has two features. First, when a page fault occurs in the main memory, the proposal allocates it to DRAM, regardless of operation types such as read or write. The page allocated by the page fault is likely to be high probability of re-reference in the near future. Our allocation can reduce the frequency of write operations in PCM. Second, if the write operations are frequently performed on pages of PCM, the pages are migrated from PCM to DRAM. Otherwise, the pages are maintained in PCM, to reduce the number of unnecessary page migrations from PCM. In our experiments, the proposal reduced the number of page migrations from PCM about 32.12% on average and reduced the number of write operations in PCM about 44.64% on average, compared to CLOCK-DWF. Moreover, the proposal reduced the energy consumption about 15.61%, and 3.04%, compared to other page replacement policies.

• ETRI Journal
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• 제33권2호
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• pp.267-274
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• 2011

This paper proposes an efficient masking method for the block cipher SEED that is standardized in Korea. The nonlinear parts of SEED consist of two S-boxes and modular additions. However, the masked version of these nonlinear parts requires excessive RAM usage and a large number of operations. Protecting SEED by the general masking method requires 512 bytes of RAM corresponding to masked S-boxes and a large number of operations corresponding to the masked addition. This paper proposes a new-style masked S-box which can reduce the amount of operations of the masking addition process as well as the RAM usage. The proposed masked SEED, equipped with the new-style masked S-box, reduces the RAM requirements to 288 bytes, and it also reduces the processing time by 38% compared with the masked SEED using the general masked S-box. The proposed method also applies to other block ciphers with the same nonlinear operations.

• East Asian mathematical journal
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• 제19권1호
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• pp.17-26
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• 2003

This paper demonstrates the CAS technique of analyzing the nature and the structure of the numerical error for education and research purposes. This also illustrates the CAS approach in experimenting with the numerical operations in an arbitrary computer number system and also in doing error analysis in a visual manner.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제7권3호
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• pp.205-208
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• 2007

Measuring the similarity between fuzzy sets plays a vital role in several fields. However, none of all well-known similarity measure methods is all-powerful, and all have the localization of its usage. This paper defines some operations on the similarity measures of fuzzy sets such as summation and multiplication of two similarity measures. Also, these operations will be generalized to any number of similarity measures. These operations will be very useful especially in the field of computer vision, and data retrieval because these fields need to combine and find some relations between similarity measures.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제26권1호
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• pp.85-108
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• 2012

본 연구의 목적은 도형 영역과 수와 연산 영역에서 나타나는 초등학교 3학년 학생들의 정당화 유형에 대한 반응과 오류 유형을 검사하여 학생들의 정당화 지도에 대한 시사점을 제공하는 것이다. 연구 결과는 다음과 같다. 첫째, 수와 연산 영역에서 학생들은 정당화 유형 검사지를 해결함에 있어서 경험적 정당화 유형과 분석적 정당화 유형을 고루 사용했다. 둘째, 도형 영역에서는 분석적 정당화에 비해 경험적 정당화 비율이 높게 나타났는데, 경험적 정당화와 분석적 정당화의 비율이 고루 나타난 수와 연산 영역과의 차이가 있었다. 셋째, 정당화 과정에서 발생한 학생들의 오류를 분석해 본 결과 풀이과정 생략의 오류, 개념 및 원리의 오류, 문항 이해의 오류, 기술적 오류의 순으로 나타났다. 따라서 특히 도형 영역에서는 학생들에게 경험적 정당화는 물론이고 분석적 정당화에 대한 경험을 많이 제공할 필요가 있다. 또한 학생들의 오개념 및 잘못 이해하고 있는 원리를 정확하게 파악하여 재지도할 필요가 있겠다.

• ETRI Journal
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• 제38권2호
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• pp.326-336
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• 2016

We propose and describe new error control algorithms for redundant residue number systems (RRNSs) and residue number system product codes. These algorithms employ search techniques for obtaining error values from within a set of values (that contains all possible error values). For a given RRNS, the error control algorithms have a computational complexity of $t{\cdot}O(log_2\;n+log_2\;{\bar{m}})$ comparison operations, where t denotes the error correcting capability, n denotes the number of moduli, and ${\bar{m}}$ denotes the geometric average of moduli. These algorithms avoid most modular operations. We describe a refinement to the proposed algorithms that further avoids the modular operation required in their respective first steps, with an increase of ${\lceil}log_2\;n{\rceil}$ to their computational complexity. The new algorithms provide significant computational advantages over existing methods.

• 한국경영과학회지
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• 제23권3호
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• pp.75-90
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• 1998

The improper use of input and output factors in DEA has a critical and negative impact on the efficiency measurement and the discernment of decision making units(DMUs) : hence the proper selection Process of the factors should precede the actual applications of DEA. In this paper, we propose a new approach to selecting proper factors based on Tofallis' partial efficiency evaluation method(1996). With the approach, the factors aye clustered by measuring their respective partial efficiencies and analyzing the rank correlations of them. The method and procedure we propose in this paper are then applied to measure the efficiencies of the public libraries in Seoul District area, and the results show that the proposed approach can provide meaningful information to improve discernment of the DMUs while using less number of input factors (and less information). The proposed method can be effectively used in the situation where the number of the DMUs to be considered is relatively small compared to the number of available input and output factors, which usually lessens the power to identify the inefficient units in DEA.

• 한국경영과학회지
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• 제32권3호
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• pp.17-31
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• 2007

In this paper, we consider a service system with bi-functional servers, which can switch between the primary service room and the secondary room. A service policy is characterized by the switching paints which depend on the queue length in the primary service room and the service level requirement constraint of the secondary room. The primary service room is modeled as a Markovian queueing system and the throughput of the primary service room is function of the total number of bi-functional servers. the buffer capacity of the primary service room, and the service policy. There is a revenue obtained from throughput and costs due to servers and buffers. We study the problem of simuitaneously determining the optimal number of servers, buffer capacity, and service policy to maximize profit of the service system, and develop an algorithm which can be successfully applied with the small number of computations.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.311-314
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• 2004

The 2 DBPP(Two-Dimensional Bin Packing Problem) is a problem of packing each item into a bin so that no two items overlap and the number of required bins is minimized under the set of rectangular items which may not be rotated and an unlimited number of identical rectangular bins. The 2 DBPP is strongly NP-hard and finds many practical applications in industry. In this paper we discuss a tabu search approach which includes tabu list, intensifying and diversification strategies. The HNFDH(Hybrid Next Fit Decreasing Height) algorithm is used as an internal algorithm. We find that use of the proper parameter and function such as maximum number of tabu list and space utilization function yields a good solution in a reduced time. We present a tabu search algorithm and its performance through extensive computational experiments.