• Journal of the Korean Institute of Navigation
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• v.21 no.2
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• pp.1-9
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• 1997

This paper presented a method of evaluating navigational safety of a ship by means fo the integrted seakeeping performance index(ISPI). The ISPI is defined by measuring only any one factor through the medium of relative dangerousness of the other factors for evaluating seakeeping performance. This evaluation method can be applied to the ships for any types and loading conditions. In devloping the practical evaluation system of navigational safety, it is expected to be useful to solve the difficulties in measuring factors by sensors. The results are also useful for devloping the optimum type of ship by applying at the initial design phase.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1997.04a
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• pp.5-16
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• 1997

This paper presented a method of evaluting navigational safety of a ship by means of the integrated seakeeping performance index(ISPI). The ISPI is defined by measuring only any one factor through the medium of relative dangerousness of the other factors for evaluating seakeeping performance. This evaluation method can be applied to the ships for any types and loading conditions. In developing the practical evaluation system of navigational safety. it is expected to be useful for developing the optimum type of ship by applying at the initial design phase.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.5
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• pp.95-101
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• 2008

Modeling of stock prices forecast has been considered as one of the most difficult problem to develop accurately since stock prices are highly correlated with various environmental conditions including economics and political situation. In this paper, we propose a agent system approach to predict Korea Composite Stock Price Index (KOSPI) using neural network and statistical methods. To minimize mean of prediction error and variation of prediction error, agent system includes sub-agent modules for feature extraction, variables selection, forecast engine selection, and forecasting results analysis. As a first step to develop agent system for KOSPI forecasting, twelve economic indices are selected from twenty two basic standard economic indices using principal component analysis. From selected twelve economic indices, prediction model input variables are chosen again using best-subsets regression method. Two different types data are tested for KOSPI forecasting and the Prediction results showed 11.92 points of root mean squared error for consecutive thirty days of prediction. Also, it is shown that proposed agent system approach for KOSPI forecast is effective since required types and numbers of prediction variables are time-varying, so adaptable selection of modeling inputs and prediction engine are essential for reliable and accurate forecast model.

• Tunnel and Underground Space
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• v.29 no.6
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• pp.379-393
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• 2019

For the economical construction of a tunnel by TBM, the selection of TBM optimized with the various project conditions is important, and also necessary to predict the performances of selected TBM in advance. This study was conducted to comprehensively evaluate the performance of the EPB shield TBM screw conveyor by the discrete element method. The sticky particles were used for the excavated material models, and screw conveyor with 11 different inclined angles were simulated to evaluate the performance depending on the different inclined angles. The four different rotational speed conditions of the screw were used, and torque, required power, extra energy for muck discharge, and the muck discharge rate were selected as four performance indicators. As a result, the optimized inclined angle was selected, and selected angle accords with the fact that EPB shield TBM screw conveyor is generally installed and adjusted at the inclined angle between 20.0° and 30.0° in the field.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.90-90
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• 2020

상수관망시스템은 관할 지역 내 생활 및 공업용수를 공급하기 위한 사회기반시설물로써, 비상시에도 사용자의 용수 수요를 충족하기 위한 안정적인 성능이 요구된다. 이러한 상수관망시스템의 용수공급능력은 비상시 용수공급가능량, 공급수압 등 여러 가지 수리해석 결과를 통해 판단할 수 있다. 그러나, 시스템의 설계 및 운영 과정에서 다양한 성능들을 시간·공간적으로 모두 고려하는 것은 매우 복잡한 과정을 거치므로, 복합적인 용수공급 성능을 집약적으로 평가하기 위한 신뢰도 지수들이 개발되었다. 여기서 신뢰도 지수들은 각각의 이론적 접근방법에 따라 시스템의 특정 성능에 다소 편중된 평가 결과를 갖는 것으로 알려져 있으며, 따라서 상수관망시스템의 설계 및 운영 시, 목적과 특성에 맞는 적합한 신뢰도 지수를 선정하고, 적용하기 위한 분석이 필요하다. 본 연구에서는 상수관망시스템의 구조적 특성 및 핵심 성능에 따른 신뢰도 지수별 적용성을 평가하기 위해, 다양한 형태의 네트워크에서 몇 가지 공급부하 시나리오를 바탕으로 수리해석 결과와 신뢰도 지수 간의 상관성을 분석하였다. 또한, 다기준 분석기법을 통해 종합적인 시스템 핵심 성능에 대한 신뢰도 지수의 상관성을 분석함으로써, 시스템 전반에 대한 신뢰도 지수별 적용성을 함께 평가하였다. 본 연구 결과는 향후 상수관망시스템의 설계 또는 기존 시스템의 보강 및 운영계획 수립 등을 위한 연구에서 폭넓게 활용할 수 있을 것으로 기대된다.

• Journal of Korea Multimedia Society
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• v.13 no.4
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• pp.487-495
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• 2010

It has been required to develop an accurate and reliable evaluation method for the performance of biometric systems as their use is getting popular. Among a number of biometric systems, face recognition is one of the most widely used techniques and this leads to develop a stable evaluation method for face recognition systems in order to standardize the performance of face recognition systems. However, it is considered as a difficult task to evaluation such systems due to a large number of factors that affect their performance. Thus, it may be infeasible to take into account all the environmental factors that are related to the performance of face recognition systems and this naturally suggests an evaluation method for the overall performance based on scenarios. In this paper, we have analyzed environmental factors that are related to the performance of general face recognition systems and proposed their evaluation method taking into account those factors. We have proposed an evaluation method based on scenario that considers the combination of individual environment factors instead of evaluating the performance of face recognition systems regarding each factor. Indeed, we have presented examples on the evaluation of face recognition systems based on scenario that takes into account overall environmental factors.

• Journal of the Korean Society of Marine Environment & Safety
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• v.4 no.2
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• pp.43-52
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• 1998

Generally, the navigational safety of a ship under various loading conditions is evaluated by a loading manual. However, the loading manual handles only statical factors such as weight and buoyancy of ship without including any wave conditions. Practically ship's safety is much concerned with the occurrences on the rough sea as propeller racing, rolling, deck wetness, vertical acceleration, lateral acceleration, slamming and so on. The purpose of this paper is to present a synthetic and practical evaluation method of navigational safety using the integrated seakeeping performance index(ISPI) under loading conditions of ship in seaways. The method is calculated by means of the ISPI by measuring only vertical acceleration. Judgement of dangerousness is carried out for four lading conditions : homogeneous full loaded, half loaded, heavy ballast loaded, and normal ballast loaded conditions. In developing the practical evaluation system of navigational safety, it is useful to solve the difficulties in measuring factors by sensors. And by applying the evaluation diagrames, navigators are able to avoid dangerousness by keeping away of the danger encountering angle of wave direction which the diagram shows.

• Convergence Security Journal
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• v.11 no.1
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• pp.39-48
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• 2011

QoS(Quality of Service) is defined "The collective effect of service performance which determines the degree of satisfaction of a user of the service" by ITU-T Rec. E.800. The final goal of information system is to secure the performance efficiency within the required time. The security QoS framework is the modeling of the QoS measurement metrics, the measurement time schedule, instrument, method of measurement and the series of methodology about analysis of the result of measurement. This paper relates to implementing issue and performance measuring about blended mechanism between networking technology and security technology. We got more effectiveness in overall network security, when applying and composing amalgamated security mechanism between network technology and security technology. In this paper, we suggest techniques being used on infrastructure system and also offers a security QoS methodology as a model of more effective way. Methodology proposed in this research has proven that it is possible to measure response time through the scheduled method.

• Journal of the Korean Society for information Management
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• v.36 no.4
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• pp.83-105
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• 2019

This study aims to suggest an effective method for the automatic classification of keywords with similar patterns by calculating pattern similarity of temporal data. For this, large scale news on the Web were collected and time series data composed of 120 time segments were built. To make training data set for the performance test of the proposed model, 440 representative keywords were manually classified according to 8 types of trend. This study introduces a Dynamic Time Warping(DTW) method which have been commonly used in the field of time series analytics, and proposes an application model, MA-DTW based on a Moving Average(MA) method which gives a good explanation on a tendency of trend curve. As a result of the automatic classification by a k-Nearest Neighbor(kNN) algorithm, Euclidean Distance(ED) and DTW showed 48.2% and 66.6% of maximum micro-averaged F1 score respectively, whereas the proposed model represented 74.3% of the best micro-averaged F1 score. In all respect of the comprehensive experiments, the suggested model outperformed the methods of ED and DTW.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.181-191
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• 2010

Lightweight panels are currently used in many ways, such as inner walls of the skyscrapers and residential buildings in Korea. Moreover there has been an increasing of interest in developing construction method and quality improvement as many buildings became higher, because there are more advantages like constructability, finishability, and economic efficiency, etc. than previous heavy weight concrete wall. It is necessary to analyze the characteristics and evaluate the performance of lightweight panels when selecting proper methods and materials to building characteristics and builder's demand. However, there doesn't exist systematic data with a classification of lightweight panels' type and performance. The purpose of this study is to classify domestic lightweight panels by both type of exterior board and construction method, and also to evaluate each performance by surveying user's opinion.