• 한국문헌정보학회지
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• 제32권1호
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• pp.169-187
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• 1998

본 연구의 목적은 전자형 색인초록이 도서관 및 정보기관에 도입되어 있음에도 불구하고 계속 인쇄형 색인초록을 이용하는 이용자는 어떤 개인적 특성을 보이고 있으며, 어떤 행태를 지니고 있는지를 전자형 색인초록 이용행태와 비교함으로써 인쇄형 색인초록이 지니고 있는 특성을 밝히는데 있다. 결론을 요약하면 이용자들은 논문작성시 확실한 연구논제를 정하지 못한 상태에서 연구의 주제를 얻기 위하여 인쇄형 색인초록을 이용하는 반면, 확실한 논제가 정해진 상태에서는 선행연구조사와 같은 포괄적인 조사를 하기 위해서 전자형 색인초록을 이용하고 있고 인쇄형 색인초록 이용자들은 탐색과정 중 자신에게 필요한 문헌인지 아닌지를 결정하는 판단력으로 인하여 탐색결과 만족도가 전자형 색인초록 이용자보다 다소 더 높으며, 전자형 색인초록 이용자는 인쇄형 색인초록 이용자보다 탐색결과 분석을 위해 별도의 시간을 더 많이 할애하고 있다. 전자형 색인초록 이용자는 인쇄형 색인초록 이용자보다 탐색실패 경험이 더 많았으며, 탐색실패 후 각 유형의 색인초록 이용자 모두 높은 응답율로 다른 색인초록을 통한 재탐색을 시도하였다. 인쇄형 색인초록 이용자는 전자형 색인초록 이용자에 비해 온라인 탐색지식이 월등하게 적은 것으로 나타났다.

• 한국정보과학회논문지:시스템및이론
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• 제32권1호
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• pp.9-20
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• 2005

최근 멀티미디어 정보를 기술하기 위한 표준인 MPEG-7이 제안되어 이미지/동영상 검색 시스템과 간은 응용분야에서 사용되기 시작하였다. 그러나 MPEG-7 시각 정보 기술자들은 대부분 고차원으로 표현이 되고, 고차원에서 발생되는 문제인 "Curse of dimensionality" 때문에 기존의 인덱싱 방법(예를 들면 트리 구조를 이용하는 다차원 인덱싱 방법, 차원을 줄이는 방법, 양자화 등의 압축 기법을 이용하는 방법 등)으로는 효율적인 검색을 할 수 없다. 본 논문에서는 MPEG-7 시각 정보 기술자들의 특징을 반영한 효율적인 인덱싱 방법을 제안한다. 제안된 방법에서는 기술자를 속성 히스토그램으로 변형하고 히스토그램의 자 빈 값을 이진 형태로 표현하여 비트열을 생성하며, 이러한 비트열들을 이용하여 비트맵 인덱스를 구성한다. 질의 오브젝트가 입력되면 비트맵 인덱스를 이용하여 결과에 포함될 가능성이 있는 후보 오브젝트 리스트를 생성하게 되는데 즉, 각 오브젝트의 인덱스와 질의 오브젝트의 비트열에 대한 XOR(Exclusive OR) 연산을 수행하여서 후보 오브젝트 리스트를 생성한다. 그리고 이 리스트에 있는 오브젝트들에 대해서만 L1-norm과 같은, 기술자를 위해 사용되는 비교 연산식을 수행하여 최종 결과 오브젝트들을 사용자에게 보여주게 된다. 본 논문에서 제안하는 알고리즘은 단순한 비트 연산을 통해 검색 결과에 포함될 가능성이 있는 오브젝트들을 추출해낼 수 있기 때문에 빠른 시간 내에 검색을 마칠 수 있도록 해준다. 실험에 의하면 제안한 방법을 이용하는 경우, 90% 이상의 정확도를 유지하면서 검색 시간에서는 순차 검색에 비해 15배 이상의 속도 향상을 보임을 알 수 있었다.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1994년도 추계학술발표회 초록집
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• pp.146-149
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• 1994

A nonlinear dynamic optimization has been performed for reactor power control system of CANDU 6 nuclear power plant considering xenon, fuel and moderator temperature feedback effects. Integral-of-Time-multiplied Absolute-Error (ITAE) criterion has been used as a performance index of the system behavior. Optimum controller gain are found by searching algorithm of Sequential Quadratic Programming (SQP). System models are referenced from most recent literatures. Signal flow network construction and optimization have been done by using commercial computer software package.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권10호
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• pp.4908-4928
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• 2017

Recent research into wireless sensor network (WSN)-related technology that senses various data has recognized the need for spatio-temporal queries for searching necessary data from wireless sensor nodes. Answers to the queries are transmitted from sensor nodes, and for the efficient transmission of the sensed data to the application server, research on index processing methods that increase accuracy while reducing the energy consumption in the node and minimizing query delays has been conducted extensively. Previous research has emphasized the importance of accuracy and energy efficiency of the sensor node's routing process. In this study, we propose an itinerary-based R-tree (IR-tree) to solve the existing problems of spatial query processing methods such as efficient processing and expansion of the query to the spatio-temporal domain.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.736-742
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• 2008

This paper proposes new searching algorithm for the optimal PD gains of flexible rotor supported by active magnetic bearings. Under the assumption of linearized bearing parameters with respect to PD gains, the performance index in quadratic form is defined and steepest descent method is adopted for determining local minimum. Moreover, the eigenpair sensitivity concept is utilized to evaluate the sensitivity of performance index. To evaluate the effectiveness of suggested algorithm, the finite element model is constructed and its reduced model is retained in modal domain. Given starting gains, the optimal gains are successfully found and the control performance is demonstrated by simulation to show the efficiency of the proposed method.

• 대한기계학회논문집A
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• 제30권8호
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• pp.889-896
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• 2006

The concept of reliability has been applied to the topology optimization based on a reliability index approach or a performance measure approach. Since these approaches, called double-loop single vector approach, require the nested optimization problem to obtain the most probable point in the probabilistic design domain, the time for the entire process makes the practical use infeasible. In this work, new reliability-based topology optimization method is proposed by utilizing single-loop single-vector approach, which approximates searching the most probable point analytically, to reduce the time cost. The results of design examples show that the proposed method provides efficiency curtailing the time for the optimization process and accuracy satisfying the specified reliability.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.979-983
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• 2001

We develop a new method of simultaneous optimization of trajectory and shape of redundant flexible manipulators for collision-free utilizing the B-spline function and a mathematical programming method We adopt an approximate flexible manipulator model which consists of rigid bar elements and spring elements. We use B-spline function for determining the approximate trajectory and the expressions of the outline of obstacles. The used total performance index consists of 2 performance indices. The first is the driving energy, and the second is the trajectory deviation which is caused by the approximate modeling for the flexible manipulator. We design optimal collision-free trajectory of flexible manipulators by searching optimum positions of the control points for B-spline approximation which minimize the performance index subject to constraint condition for collision-free. Some examinations through numerical examples show the effectiveness of the method

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권3호
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• pp.1091-1110
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• 2016

Hybrid deployment under current cloud data centers is a combination of online and offline services, which improves the utilization of the cluster resources. However, the performance of the cluster is often affected by the online services in the hybrid deployment environment. To improve the response time of online service (e.g. search engine), an effective scheduling algorithm based on Storm is proposed. At the component level, the algorithm dispatches the component with more influence to the optimal performance node. Inside the component, a reasonable resource allocation strategy is used. By searching the compressed index first and then filtering the complete index, the execution speed of the component is improved with similar accuracy. Experiments show that our algorithm can guarantee search accuracy of 95.94%, while increasing the response speed by 68.03%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권7호
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• pp.3578-3593
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• 2017

Given two collections of objects that carry both spatial and textual information in the form of tags, a $\text\underline{S}patio$-$\text\underline{T}extual$-based object $\text\underline{S}imilarity$ $\text\underline{JOIN}$ (ST-SJOIN) retrieves the pairs of objects that are textually similar and spatially close. In this paper, we have proposed a block index-based approach called BIST-JOIN to facilitate the efficient ST-SJOIN processing. In this approach, a dual-feature distance plane (DFDP) is first partitioned into some blocks based on four segmentation schemes, and the ST-SJOIN is then transformed into searching the object pairs falling in some affected blocks in the DFDP. Extensive experiments on real and synthetic datasets demonstrate that our proposed join method outperforms the state-of-the-art solutions.

• 한국조경학회지
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• 제32권2호
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• pp.55-67
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• 2004

This study aims to analyze the actual state, the satisfaction index, and the satisfaction factor of the residents in the apartment adopting thematic outdoor rest space design. This study also proposes the basic data for the standard of resident-centered rest space design, not designer-centered or fashion-followed design. The results are as follows : First, most residents use near by rest space, and more use occur during the evenings; 17 hr. ∼ 21 hr. Most of residents use the rest space with their children, partner, or family. Residents usually take walks and take a rests in the rest space. Most residents use the rest space quietly. Of the rest facilities in the outdoor rest space, benches are most used, walks and pergolas are more frequently used. But waterscape facilities are not particularly used. The satisfaction index of the outdoor rest space is generally low. However, the satisfaction index of the rest space and facilities type shows that the evaluation of rest facilities(e.g. benches) is high. The satisfaction index of the decoration shows that the evaluation for the color and design of facilities is high. In the satisfaction index of the physical environment, the item about the size of rest space is highly appreciated. In the mental satisfaction index of the rest space, the item about whole atmosphere is highly appreciated. Of the factors affecting the general satisfaction index with outdoor rest space, the factor of physical environment is the most important independent-variable. Physical environment and facilities are more important influential factors than the atmosphere of outdoor rest space. In the future, the practical study searching for the preferences of the residents and the activation of use should be preceded.