• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.656-659
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• 2005

his paper develops the systematic and quantitative priority-determining method for national investment using the framework of evaluating R&D. This study proposes multi criteria for evaluating the R&D of New & Renewable Energy through analysing the attribute of 11 types of energy. The framework is constituted by 4 criteria, the political urgency, economic impact, regional constraint. and technological attribute and the each criteria has 3 or 4 sub-criteria. These sub-criteria are weighted using AHP.

• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 2007년도 정기학술대회
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• pp.440-449
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• 2007

This paper provides a fine-grained analysis of Korean serial verb constructions within the HPSG framework, and covers major descriptive characteristics of the phenomena. This paper discusses constraints on serial verb constructions in terms of four aspects; transitivity, argument structure, semantic properties, and complementizers. As a result, 17 constraints have been built, which support the type hierarchies for Korean serial verb constructions. This paper also presents a sample derivation on the basis of on the constraints and the type hierarchies.

• 한국산학기술학회논문지
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• 제11권12호
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• pp.5015-5022
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• 2010

기존의 패턴 탐사 기법들은 대부분 객체가 갖는 공간 정보의 연속적인 변화에 대한 패턴 탐사는 가능하나, 추출하고자 하는 패턴에 반드시 포함되어야 하는 공간 정보에 대한 제약이 없어 특정 지점들 사이의 최적 경로 탐색 문제나 단위기간 동안 이동 객체가 순회해야 하는 지점들에 대한 경로 예측 문제 등에 적용하기 어렵다. 본 논문에서는 Road Network 상의 특정한 지점들 사이를 이동한 객체의 위치 데이터들 중 최다 빈발 패턴과 시간 및 비용 등의 가중치를 복합적으로 고려하여 최적의 이동 경로를 탐색하는 방법(Spatial-Temporal Optimal Moving Pattern(with Frequency & Weight) algorithm)[13]을 이용하여, 공간 개념 계층에 따른 경로 탐색의 정확도를 분석한다. 분석의 결과는 패턴 탐사 과정에 있어 공간 제약을 적용하여 검색 데이터 범위를 축소함으로써 데이터베이스 검색 시간을 최소화함을 보이고, 또한 공간 추상 계층의 각 계층별 영역 내 포함여부를 고려함으로써 효율적으로 최적 이동 패턴을 탐색하여 제공하도록 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권12호
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• pp.3219-3236
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• 2012

A tree routing structure is often adopted for many-to-one data gathering and aggregation in sensor networks. For real-time scenarios, considering lossy wireless links, it is an important issue how to construct a maximum-lifetime data gathering tree with delay constraint. In this work, we study the problem of lifetime-preserving and delay-constrained tree construction in unreliable sensor networks. We prove that the problem is NP-complete. A greedy approximation algorithm is proposed. We use expected transmissions count (ETX) as the link quality indicator, as well as a measure of delay. Our algorithm starts from an arbitrary least ETX tree, and iteratively adjusts the hierarchy of the tree to reduce the load on bottleneck nodes by pruning and grafting its sub-tree. The complexity of the proposed algorithm is $O(N^4)$. Finally, extensive simulations are carried out to verify our approach. Simulation results show that our algorithm provides longer lifetime in various situations compared to existing data gathering schemes.

• 한국항해항만학회지
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• 제32권7호
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• pp.553-559
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• 2008

The lorry based transportation system in korea has many problems such as high domestic logistic cost, environment pollution and road damage etc. Hereupon, the necessity of improvement for national logistics system has been proposed continuously. Therefore we carried out this research through AHP(Analytic Hierarchy Process) to measure relative importance between effect factors and constraint factors and examined the possibility of Modal Shift from lorry transportation to coastal transportation. As the results of this research, the relative priority on modal shift policy enforcement (0.556) is higher than that of maintenance of the present transportation system(0.444).

• 대한임베디드공학회논문지
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• 제2권4호
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• pp.233-241
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• 2007

In an ubiquitous environment, for controlling user access according to environment of users, a number of access control models enforcing dynamic environment of users have been proposed. However, they do not support personalized environments of each user and have a run-time overhead of searching active roles. In this paper, we propose a new model, PE-RBAC, that extends the RBAC architecture by addition of a personalized environment component as a constraint to accommodate dynamic and mobile users. In this model, a dynamic role activation is presented by using a new role-to-environment structure instead of the conventional role hierarchy, which makes it efficient to find the active roles according to a user's personalized environment.

• 전자공학회논문지A
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• 제30A권3호
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• pp.139-145
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• 1993

Partitioning is an important step in the hierarchical design of very large scale integrated circuits. In this research, a new effective partitioning algorithm based on 2-level hierarchy is presented. At the beginning, clusters are formed to reduce the problem size. To overcome the weakness of the iterative improvement techniques that the partitioning result is dependent on the initial partitioning and to consistently produce good results, the cluster-level partitioning is performed several times using several sets of parameters. Then the best result of cluster-partitioning is used as the initial solution for lower level partitioning. For each partitioning, the gradual constraint enforcing partitioning method has been used. The clustering-based partitioning algorithm has been applied to several benchmark examples and produced promising results which show that this algorithm is efficient and effective.

• 한국전자거래학회지
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• 제18권4호
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• pp.327-338
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• 2013

IT프로젝트를 수행하는 기업은 정해진 예산범위 내에서 투자계획을 수립하고 실행하게 된다. 이 과정에서 IT프로젝트를 효과적, 효율적으로 선정하는 문제는 기업경쟁력과 직결되는 중요한 요소이다. 그동안 IT프로젝트의 선정을 위한 다양한 모형이 개발되었으나 예산제약을 고려한 효과적 프로젝트 선정에 대한 연구는 보고되지 않고 있다. 본 연구에서는 예산 제약을 고려하여 효과적으로 IT프로젝트를 선정하는 기법을 제시하였다. 본 연구에서 제안한 모델(AHP-K)에서는 AHP(Analytic Hierarchy Process : 계층분석법) 기법을 적용하여 평가 항목의 가중치와 프로젝트 후보군의 가중치를 산정한 후 배낭문제(Knapsack Problem)를 적용하여 예산 범위 내에서 프로젝트 효용을 최대화하는 선정안을 도출한다. 실제 적용단계에서 고려하는 대안이 많거나 신규대안이 추가되는 경우 쌍대비교의 수행이 어려운 점을 감안하여 대안 비교 단계에서 절대평가법을 적용하였다. 본 연구에서는 제시된 모델을 실제 사례에 적용하여 기존 AHP 모형과 비교 분석함으로써 효과성을 검증하였다.

• 한국정보과학회논문지:시스템및이론
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• 제36권6호
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• pp.511-520
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• 2009

본 논문에서는 입력 볼륨 데이터와 출력 메쉬 데이터에서 모두 계층성을 지원하는 새로운 등밀도 표면의 재구성 방법을 제안한다. 제안된 방법은 먼저 입력 볼륨 데이터로부터 3차원 팽창 필터를 사용하여 볼륨 피라미드라 불리는 볼륨의 계층구조를 만든다. 볼륨 피라미드가 만들어진 후 해상도가 최저인 피라미드의 최상단 볼륨에서부터 셀경계표현 방법을 이용하여 조악한 초기 메쉬를 생성한다. 이러한 메쉬를 반복적으로 변형하여 O(3)-인접성 조건하에서 추출한 등밀도점을 잘 근사하도록 하는데, 이를 위해 SWIS (표면축소기반의 등밀도면 재구성법[6]) 알고리즘에서 사용되었던 표면 축소 단계와 평활화 단계를 사용한다. 또한 최종등밀도면의 정밀한 표면을 만들 수 있도록 메쉬를 반복적으로 분할(subdivision)한다. 제안된 방법은 생성되는 표면이 표면의 압축이나 점진적인 전송 등과 같은 다중 해상도 알고리즘에 활용될 수 있다는 장점이 있다.

• Journal of Information Processing Systems
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• 제16권4호
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• pp.845-858
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• 2020

This paper proposes a modified end-to-end secure low energy adaptive clustering hierarchy (ME-LEACH) algorithm for enhancing the lifetime of a wireless sensor network (WSN). Energy limitations are a major constraint in WSNs, hence every activity in a WSN must efficiently utilize energy. Several protocols have been introduced to modulate the way a WSN sends and receives information. The end-to-end secure low energy adaptive clustering hierarchy (E-LEACH) protocol is a hierarchical routing protocol algorithm proposed to solve high-energy dissipation problems. Other methods that explore the presence of the most powerful nodes on each cluster as cluster heads (CHs) are the sparsity-aware energy efficient clustering (SEEC) protocol and an energy efficient clustering-based routing protocol that uses an enhanced cluster formation technique accompanied by the fuzzy logic (EERRCUF) method. However, each CH in the E-LEACH method sends data directly to the base station causing high energy consumption. SEEC uses a lot of energy to identify the most powerful sensor nodes, while EERRCUF spends high amounts of energy to determine the super cluster head (SCH). In the proposed method, a CH will search for the nearest CH and use it as the next hop. The formation of CH chains serves as a path to the base station. Experiments were conducted to determine the performance of the ME-LEACH algorithm. The results show that ME-LEACH has a more stable and higher throughput than SEEC and EERRCUF and has a 35.2% better network lifetime than the E-LEACH algorithm.