• 인터넷정보학회논문지
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• 제12권4호
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• pp.157-172
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• 2011

최근 분산 OLAP은 분산 환경에 적용하기 위하여 DHT기반의 P2P OLAP과 그리드 OLAP연구가 활발하게 진행되고 있다. 그러나 클라우드 컴퓨팅 환경에 적용하기 위하여 P2P OLAP은 structured P2P 특성 때문에 다차원 범위 질의에 문제점이 있고, Grid OLAP은 인접성 및 시계열 고려가 없기 때문에 쿼리 자체의 서브 �V 조회 알고리즘 연구에 치중되어 있다. 따라서 본 논문은 클라우드 컴퓨팅에 적합한 환경 제공을 위해 사용자의 조회 결과가 시계열적 특성으로 여러 사용자에 의해 재사용이 가능하고, 서버상의 휘발성 조회 큐브가 사용자 로컬 메모리에서 직접 분석 질의 시 효율이 좋다는 것에 초점을 두어 중앙관리 P2P방식을 제안하였다. 또한 빠른 질의 결과 및 다차원 범위질의를 위한 다단계 Hybrid P2P방식에 인덱스 부하 분산 및 성능 향상을 위한 클라우드 시스템을 접목하여 Cloud P2P OLAP을 제안하였다. 이를 위한 인덱스 구조로는 큐브 위상관계 트리와 인접성 2차원 Quadtree에, 시계열 Interval-트리를 접목하였으며, 이는 조회나 갱신 시에 일반 OLAP에 비해 큰 효율성을 보였다.

• 유통과학연구
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• 제13권5호
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• pp.91-102
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• 2015

Purpose - This study aims to build a systematic frame for effective marketing performances by prioritizing product type and pertinent channel that are appropriate for digital channel characteristics. FCB grid model was used to define a product type, and Internet communication satisfaction index was considered as a marketing performance measuring tool for digital channel. Research design, data, and methodology - As systematic understanding for Digital marketing is still unfamiliar to even professional marketer, the hypothesis was established based on preliminary research by conducting a qualitative survey of marketing experts who already experienced digital marketing in the fields as well as existing related study literature. Through a preliminary research, the degree for understanding for digital marketing, current digital marketing (including product/channel mix) execution status, and difficulties for marketers who had experienced digital marketing were figured out. Based on preliminary research, the main part of survey was designed to examine which type of product would be effective for digital marketing and which digital channel would be effective to achieve marketing performance in line with marketing objectives. To collect data, the questionnaire survey was conducted for professional marketers who had experienced digital marketing in 10 different fields including FMCG, cosmetics, distribution industry for one month (July, 10, 2014~Aug, 10, 2014). A total of 90 questionnaire were distributed and 66 questionnaires were used for the analysis, excluding the unanswered and insincere questionnaires. The data were analysed using SPSS ver.18.0. Results - The analysis for product type which is pertinent to digital marketing and prioritization for digital channel per digital marketing performance type could be summarized as followings. First, high involvement buying decision type of product and rational purchasing decision type of product in FCB grid are more effective for digital marketing in terms of marketing performance. Therefore, marketers in field would prioritize considering product type before executing digital marketing. Second, factor for sales increase, potential consumer creation and brand awareness was represented respectively 31.25%, 21.9%, and 20.8% as a result of factor analysis in terms of digital marketing channel performance. Third, effective major digital channel per digital marketing performance factor was differently identified as each digital channel has its own peculiarity. For instance, search engine is more effective for increasing sales while social media such as facebook and Kakaotalk is more effective for encouraging consumer participation. Conclusions - As a result of this study, product type and peculiarity which were pertinently fit to digital marketing were identified by using FCB grid model, and also suggested framework for decision making of digital channel selection in line with marketing objectives for effective marketing performance. It also provided insight to professional marketer which type of product could be effective for digital marketing execution as well as which factors should be measured for digital marketing performance.

• 한국산학기술학회논문지
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• 제17권1호
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• pp.9-14
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• 2016

본 논문에서는 인체 감지형 자기장 코일의 감지거리 13.4mm를 이용한 디지털 잠금장치 설계에 관한 연구를 하고자 한다. 현재 사용되는 디지털 잠금장치와는 다르게 실외 케이스는 기존의 고유번호 입력버튼, 조명, 보호 커버, 해당 pcb, 외곽 케이스, 데이터 전송 케이블 등이 삭제되고 구동전원 ON/OFF 스위치와 비상 단자로만 구성하였다. 실내 케이스는 내부에 설치 된 자기장 코일기판이 유리문 몸체에 밀착된 상태로 12mm 간격의 맞은편 실외에서 전송되는 전기적 저항 값을 감지하면 그에 대응하는 유도전류가 흐르게 된다. 이때, 해당 원형 코일의 주파수 변환이 이루어지면 자기장 코일은 센서의 역할을 수행하게 된다. 센서로서의 자기장 코일은 인체가 감지되기 전과 감지 후에 출력되는 발진 주파수의 크기 변화를 감지하고 2,000%이상 증폭시켜 디지털 신호로 변환 조합한 다음 전용 소프트웨어에 전송하여 내장된 고정 데이터와 비교하여 검색하는 역할을 한다. 연구결과 자기장 코일 $12.8{\emptyset}$ 기준으로 인체의 터치 면적에 따른 감지시간은 30% 대비 0.08sec, 80% 대비 0.03sec이며 감지거리는 13.4mm로 최고 수준으로 측정되었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1939-1944
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• 2003

This paper presents a global path planning algorithm based on a visibility graph method, and applies additionally various constraints for constructing the reduced visibility graph. The modification algorithm for generating the rounded path is applied to the globally shortest path of the visibility graph using the robot size constraint in order to avoid the obstacle. In order to check the visibility in given 3D map data, 3D CAD data with VRML format is projected to the 2D plane of the mobile robot, and the projected map is converted into an image for easy map analysis. The image processing are applied to this grid map for extracting the obstacles and the free space. Generally, the tree size of visibility graph is proportional to the factorial of the number of the corner points. In order to reduce the tree size and search the shortest path efficiently, the various constraints are proposed. After short paths that crosses the corner points of obstacles lists up, the shortest path among these paths is selected and it is modified to the combination of the line path and the arc path for the mobile robot to avoid the obstacles and follow the rounded path in the environment. The proposed path planning algorithm is applied to the mobile robot LCAR-III.

• Journal of Electrical Engineering and Technology
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• 제6권4호
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• pp.431-438
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• 2011

To ensure that equipment outages do not directly impact the reliability of the ISO-controlled grid, market participants request permission and receive approval for planned outages from the independent system operator (ISO) in competitive electricity markets. In the face of major generation outages, the ISO will make a critical decision as regards the scheduling of the essential maintenance for myriads of generating units over a fixed planning horizon in accordance with security and adequacy assessments. Mainly, we are concerned with a fundamental framework for ISO's maintenance coordination in order to determine precedence of conflicting outages. Simulated annealing, a powerful, general-purpose optimization methodology suitable for real combinatorial search problems, is used. Generally, the ISO will put forward its best effort to adjust individual generator maintenance schedules according to the time preferences of each power generator (GENCO) by taking advantage of several factors such as installed capacity and relative weightings assigned to the GENCOs. Thus, computer testing on a four-GENCO model is conducted to demonstrate the effectiveness of the proposed method and the applicability of the solution scheme to large-scale maintenance scheduling coordination problems.

• 조명전기설비학회논문지
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• 제19권7호
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• pp.53-59
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• 2005

본 논문에서는 비젼 시스템을 사용하여 마이크로 BGA 소자의 2차원 결함을 검사하는 알고리즘을 제안하였다. 제안한 방법은 정밀도를 높이기 위해 부화소 알고리즘을 사용하였으며, 입력된 영상에서 패키지 영역을 추출하고, 추출된 영역에서 볼 탐색창 방법을 사용하여 볼 영역을 추출한다. 이렇게 추출된 볼 영역에 대해 결함검사에 필요한 파라미터들을 추출하고, 이들을 사용하여 소자의 불량 유무를 판정한다. 모의실험을 통해 볼 검사 정밀도의 평균 오차가 17[${\mu}m$]가 됨을 확인하였다.

• Structural Engineering and Mechanics
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• 제63권1호
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• pp.115-124
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• 2017

In this paper, a different technique to predict the effects of soil-structure interaction (SSI) on seismic response of building systems is investigated. The technique use a machine learning algorithm called Support Vector Regression (SVR) with technical and analytical results as input features. Normally, the effects of SSI on seismic response of existing building systems can be identified by different types of large data sets. Therefore, predicting and estimating the seismic response of building is a difficult task. It is possible to approximate a real valued function of the seismic response and make accurate investing choices regarding the design of building system and reduce the risk involved, by giving the right experimental and/or numerical data to a machine learning regression, such as SVR. The seismic response of both single-degree-of-freedom system and six-storey RC frame which can be represent of a broad range of existing structures, is estimated using proposed SVR model, while allowing flexibility of the soil-foundation system and SSI effects. The seismic response of both single-degree-of-freedom system and six-storey RC frame which can be represent of a broad range of existing structures, is estimated using proposed SVR model, while allowing flexibility of the soil-foundation system and SSI effects. The results show that the performance of the technique can be predicted by reducing the number of real data input features. Further, performance enhancement was achieved by optimizing the RBF kernel and SVR parameters through grid search.

• 한국도서관정보학회지
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• 제38권3호
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• pp.117-138
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• 2007

초고전압투과 전자현미경(HVEM)을 이용한 e-Science 환경을 구축하기 위해서는 HVEM의 원격제어시스템과 HVEM에 의해 생성된 데이터의 효율적인 관리와 공유를 위한 데이터포털이 필요하다. 그리고 이러한 데이터포털에서 생성된 데이터의 구조화, 저장 및 관리, 탐색, 공유를 위해서는 HVEM에 적합하게 특화된 메타데이터가 필요하다. 본 연구에서는 e-Science 환경 하에서 HVEM에 의해 생성된 데이터의 보다 효율적인 관리와 공유를 위하여 HVEM에 적합하게 특화된 메타데이터 모형을 제시하였다.

• International Journal of Contents
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• 제3권2호
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• pp.6-17
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• 2007

Emerging modem database applications require multi-dimensional index structures to provide high performance for data retrieval. In order for a multi-dimensional index structure to be integrated into a commercial database system, efficient techniques that provide transactional access to data through this index structure are necessary. The techniques must support all degrees of isolation offered by the database system. Especially degree 3 isolation, called "no phantom read," protects search ranges from concurrent insertions and the rollbacks of deletions. In this paper, we propose a new phantom protection method for multi-dimensional index structures that uses a multi-level grid technique. The proposed mechanism is independent of the type of the multi-dimensional index structure, i.e., it can be applied to all types of index structures such as tree-based, file-based, and hash-based index structures. In addition, it has a low development cost and achieves high concurrency with a low lock overhead. It is shown through various experiments that the proposed method outperforms existing phantom protection methods for multi-dimensional index structures.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.803-808
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• 2002

A computer-aided alloy-designing technique to develop the insert metal for transient liquid phase (TLP) bonding was applied to high aluminum Ni-base superalloys. The main procedure of a mathematical programming method was to obtain the optimal chemical composition through rationally compromising the plural objective performances of insert metal by a grid-search which involved data estimation from the limited experimental data using interpolation method. The objective function Z which was introduced as an index of bonding performance of insert metal involved the melting point, hardness (strength), formability of brittle phases and void ratio (bonding defects) in bond layer as the evaluating factors. The contour maps of objective function Z were also obtained applying the interpolation method. The compositions of Ni-3.0%Cr-4.0%B-0.5%Ce (for ${\gamma}$/${\gamma}$/${\beta}$ type alloy) and Ni3.5%Cr-3.5%B-3%Ti (for ${\gamma}$/${\gamma}$ type alloy) which optimized the objective function were determined as insert metal. SEM observations revealed that the microstructure in bond layers using the newly developed insert metals indicated quite sound morphologies without forming microconstituents and voids. The creep rupture properties of both joints were much improved compared to a commercial insert metal of MBF-80 (Ni-15.5%Cr-3.7%B), and were fairly comparable to those of base metals.