• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.04a
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• pp.173-186
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• 2002

서로 다른 공간해상도와 분광해상도를 가진 영상들을 이용하여 영상지도를 제작할 때 공간해상도를 향상시킬 수 있는 영상융합기법에 대해 연구하였다. 사용된 영상은 IKONOS panchromatic 영상과 multispectral 위성영상, KOMPSAT-1호 위성영상과 SPOT XS 위성영상에 대해 Brovey, IHS, PCA, HPF, CN, MWD 융합기법을 적용하여 시각적 분석, 공간정보의 분포특성, 통계적 특성을 기준으로 분석하였으며, 시각적 분석에서는 IHS, PCA 융합기법이, 통계적 분석에서는 HPF, MWD 융합기법이 좋은 결과를 보여주었으며, 종합적인 결과분석을 고려할 때 MWD 융합기법이 원 영상의 분광정보를 가장 작게 왜곡시킴을 알 수 있었다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.157-163
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• 2016

If trace-driven or execution-driven simulation is used for the performance analysis of asymmetric multi-core processors, excessive time and much disk space are necessary. In this paper, statistical simulations are performed for asymmetric multi-core processors with various hardware configurations. For the experiment, SPEC 2000 benchmark programs are used for profiling and synthesis, which is supplied as input for the simulation of asymmetric multi-core processors. As a result, the performance of asymmetric multi-core processor obtained by statistical simulation is comparable to that of the trace-driven simulation with a tremendous reduction in the simulation time.

• The Journal of the Acoustical Society of Korea
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• v.34 no.1
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• pp.75-81
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• 2015

In active sonar system, clutters degrade performance of target detection/tracking and overwhelm sonar operators in ASW (Antisubmarine Warfare). Conventional clutter reduction algorithms using consistency of local peaks are studied in multi-ping data and tracking filter research for active sonar was conducted. However these algorithms cannot classify target and clutters in single ping data. This paper suggests a single ping clutter reduction approach to reduce clutters in mid-frequency active sonar system using echo shape features. The algorithm performance test is conducted using real sea-trial data in heavy clutter density environment. It is confirmed that the number of clutters was reduced by about 80 % over the conventional algorithm while retaining the detection of target.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.414-416
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• 2007

6 시그마 기법은 Define 단계부터 현상에 대한 수치화를 강조하고 있어, Data의 중요성을 어떤 다른 개선활동 보다도 강조하고 있다. 그러나 현장에서 개선활동 수행시에 가장 큰 문제점은 결과지표인 Y에 대한 측정을 통한 수치화는 가능하지만 -현실적으로도 관리를 하고 있고- 제어인자인 Xs인자에 대한 수치화는 상당한 어려움을 겪고 있다. 그 이유는 가장 큰 경우가 조건변경에 의한 실험을 통해 Data를 수집하려면 상당한 불량의 발생을 감수해야 하고 그로 인한 피해를 중소기업 입장에서 감수하고 실험을 감행하는것이 쉽지 않을 것이다. 따라서 실제 현장 개선에서는 불량을 최소한 줄이기 위해서 제어인자인 Xs인자의 변동을 최소화 하다 보니 X인자의 변화에 따른 Y인자의 변동을 알 수 없어 실제로는 유의한 영향을 줌에도 불구하고 통계적인 결론에만 집착하다 보면 잘못된 판정으로 인해 실제 개선이 되지 않는 경우가 허다하다. 이 논문에서는 6 시그마 활동시 문제가 되는 통계적 기법 적용시 현실과 Data 분석의 결과가 일치하지 않을 때 현실적 판단방법을 적용하여 실질적 개선을 하는 방법과 Xs인자의 작은 변화를 감지할 수 있는 통계적 기법의 적용을 통하여 실제 개선을 할 수 있는 사례를 제시하고자 한다.

• 한국데이터정보과학회:학술대회논문집
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• 2006.04a
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• pp.221-227
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• 2006

본 연구는 경북에 소재한 식품회사인 S사의 햄 생산공정의 개선을 위하여 통계적 공정관리기법을 적용한 것이다. 햄의 중량은 햄의 품질에 대한 소비자의 신뢰와 기업의 수익성에 영향을 미치는 풍요한 요소이다. 연구의 목적은 햄 생산공정의 경제적 규격한계 확보를 통하여 기업의 이익을 극대화하는데 있나. 기본적인 통계적 공정관리 기법인 평균-범위 관리도, 공정능력분석, 측정시스템 평가분석 등을 이용하여 햄 공정을 분석하고, 최적 규격한계를 설정하였다.

• Journal of the Korean Statistical Society
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• v.20
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• pp.62-91
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• 1991

생물통계학(biometrics)의 여러 분야중 의학, 보건학, 농학 및 독성학 등 각 분야별로 지난 10년간(1981-1990) 학술전문지에 실린 논문을 통해 사용된 통계 방법론의 빈도를 연도별로 혹은 자료유형별로 조사 분석하였다. 주요 보건통계의 현황과 농업연구 분야에서의 통계적 기법 사용상의 문제점을 살펴보고 개선방향을 제시하였으며, 의과대학 교과과정 중 통계학 과목의 현황과 방법론으로써 전반적인 활용을 살펴 보았다. 또한 독성학 분야에서 일반적으로 다루어지는 통계적 문제를 소개하고 우리나라 독성학 분야 논문에서 가장 많이 다루는 것으로 나타난 용량-반응 분석기법에 대한 고찰을 하고 있다. 본 연구를 통하여 우리나라의 생물통계의 현황을 파악하고 장래의 방향을 제시하고자 한다.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.2
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• pp.171-177
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• 2011

Accuracy and computing time are considerable issues in machine learning. In general, the computing time for data analysis is increased in proportion to the size of given data. So, we need a sampling approach to reduce the size of training data. But, the accuracy of constructed model is decreased by going down the data size simultaneously. To solve this problem, we propose a new statistical sampling method having similar performance to the total data. We suggest a rule to select optimal sampling techniques according to given data structure. This paper shows a sampling method for reducing computing time with keeping the most of accuracy using cluster sampling, stratified sampling, and systematic sampling. We verify improved performance of proposed method by accuracy and computing time between sample data and total data using objective machine learning data sets.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.6
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• pp.57-68
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• 2009

Recently, damage scale of human-induced disaster is sharply increased but its occurrences and damages are so uncertain that it is hard to construct a resonable response & mitigation plan for infrastructures. Therefore, the needs for a advanced risk management technique based on a probabilistic and stochastic risk evaluation theory is increased. In this study, these evaluation methods were investigated and a advanced disaster risk evaluation method, which is based on the probabilistic or stochastic risk assessment theory and also is a quantitative evaluation technique, was suggested. With this method, the safety changes as the result of fire damage management for recent 40 years was analyzed. And the result was compared with that of Japan. Through the consilience of the traditional risk assessment method and this method, a stochastical estimation technique for the uncertainty of future disaster's damage could support a cost-effective information for a resonable decision making on disaster mitigation.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.1
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• pp.108-113
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• 2012

Routing paths are mightily important for the network security in WSNs. To maintain such routing paths, sustained path re-selection and path management are needed. Region segmentation based path selection method (RSPSM) provides a path selection method that a sensor network is divided into several subregions, so that the regional path selection and path management are available. Therefore, RSPSM can reduce energy consumption when the path re-selection process is executed. However, it is hard to guarantee optimized secure routing path at all times since the information using the path re-selection process is limited in scope. In this paper, we propose partial path selection method in each subregion using preselected partial paths made by RSPSM for routing path optimization in SEF based sensor networks. In the proposed method, the base station collects the information of the all partial paths from every subregion and then, evaluates all the candidates that can be the optimized routing path for each node using a evaluation function. After the evaluation process is done, the result is sent to each super DN using the global routing path information (GPI) message. Thus, each super DN provides the optimized secure routing paths using the GPI. We show the effectiveness of the proposed method via the simulation results. We expect that our method can be useful for the improvement of RSPSM.

• Journal of the Korea Society for Simulation
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• v.20 no.4
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• pp.31-40
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• 2011

Sensor nodes are easily exposed to malicious attackers by physical attacks. The attacker can generate various attacks using compromised nodes in a sensor network. The false report generating application layers injects the network by the compromised node. If a base station has the injected false report, a false alarm also occurs and unnecessary energy of the node is used. In order to defend the attack, a statistical en-route filtering method is proposed to filter the false report that goes to the base station as soon as possible. A path renewal method, which improves the method, is proposed to maintain a detection ability of the statistical en-route filtering method and to consume balanced energy of the node. In this paper, we proposed the secure path cycle method to consume effective energy for a path renewal. To select the secure path cycle, the base station determines through hop counts and the quantity of report transmission by an evaluation function. In addition, three methods, which are statistical en-route filter, path selection method, and path renewal method, are evaluated with our proposed method for efficient energy use. Therefore, the proposed method keeps the secure path and makes the efficiency of energy consumption high.