• Journal of Digital Convergence
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• v.16 no.10
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• pp.213-222
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• 2018

This study was conducted to derive the traffic accident risk index through the recognition of the elderly driver's driving pattern to reduce the traffic accident rate of elderly drivers and to reflect them in the renewal and return policy of driver's license accordingly. First, the traffic accident risk index is defined by analyzing the behavioral characteristics of older drivers to derive the major factors that lead to traffic accidents. Second, we present a method to measure the traffic accident risk index from the driving pattern of the elderly through the smart-phone, the camera and the distance sensor attached to the car. Finally, we derive three thresholds by computer simulation and determine the accident risk from the measured traffic accident risk index as four steps and suggest ways to ensure safe driving of older drivers. It is required to objectively assess the driving ability of an aged driver in accordance with the proposed method, and to induce the driver to reset the driver's license renewal cycle and voluntarily return the driver's license to minimize social costs due to increased traffic accidents.

• Journal of Convergence for Information Technology
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• v.9 no.6
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• pp.175-182
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• 2019

This study was conducted to test the assessment validity and examine the cut-off scores for driving risk as a part of the Self-report Assessment Forecasting Elderly Driving Risk (SAFE-DR) development project. The 132 senior drivers were categorized as either risky of 58 or safe of 74 drivers through the Drivers 65 Plus. Based on this initial assessment, we analyzed the risk prediction cut-offs. Furthermore, we tested the construct, content, and predictive validity. The cut-off score for the prediction of driving risk was found to be 74.5 points. The positive predictive value was 88.6%, and the negative predictive value was 86.3% about the cut-off score, signifying an excellent level of discrimination. Convergent validity, nomological validity, and content validity were found to be appropriate. Therefore, this study confirms that SAFE-DR is an appropriate assessment that can be used to screen dangerous elderly drivers.

• KDI Journal of Economic Policy
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• v.17 no.1
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• pp.107-126
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• 1995

본(本) 연구(硏究)는 자본거래자유화정도를 명목상의 규제완화여부에 의해 판별하는 종래의 접근방법(接近方法)에서 벗어나, 형식적(形式的) 규제여부(規制與否)에 관계없이 자본거래(資本去來)가 실질적으로 경제적(經濟的) 유인(誘引)에 따라 얼마나 활발하게 이루어지고 있는가를 측정함으로써 자본거래자유화정도(資本去來自由化程度)를 평가할 수 있는 방법을 모색하고 있다. 이와 관련해서 본 연구는 모두 5가지 접근방법을 시도하고 있다. 그 첫째는, 총대외무역량대비 자본거래량비중으로서 자본거래량이 상대적으로 증가하면 자본거래자유화정도가 높다고 본다. 둘째는, 환율절하기대를 감안한 국내외실질 금리차로서 대내외자본거래(對內外資本去來)가 자유로울수록 국내외금리차(國內外金利差)는 낮아질 것이기 때문에, 동 금리차가 낮을수록 자본자유화정도가 높다고 본다. 동 지수로서는 통화선물시장의 존재 여부에 따라 위험포함 및 불포함 대내외금리차를 사용할 수 있다. 셋째로는, 다소 복잡한 계량경제학적 방법을 통해 국내외실질금리간의 연계관계를 측정하는 방법으로서 두번째 방법의 개선에 해당된다. 그리고 넷째로는, 셋째번 방법에 의한 연계관계를 시간변동지수로 전환하여, 시간의 경과에 따른 자본자유화정도의 변화를 측정하고 있다. 마지막으로는, 자본거래를 위험자산의 국제교역관계(國際交易關係)로 파악하여, 무역에 있어서의 산업내교역지수측정방법을 자본거래에 적용하여 자본거래총유출입지수를 측정하였다. 동 지수는 저축투자갭의 보정적(補正的) 거래차원을 넘어 위험자산거래 자체를 위한 자본거래의 정도를 측정함으로써 순수하게 자본거래 자체의 메커니즘에 의해 자생적으로 일어나는 자본거래의 활성화정도에 대한 척도가 될 수 있을 것으로 판단된다. 이상의 방법들을 주로 한국(韓國), 일본(日本), 대만(臺灣) 등에 적용해서 평가한 결과 한국의 자본거래자유화정도(資本去來自由化程度)는 일본에 비해서는 낮지만 대만에 비해서는 높으며, 특히 90년대 들어 크게 향상된 것으로 평가되었다.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.4
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• pp.329-336
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• 2008

The facilities with new technologies in the recent power plants become larger and need a lot of high cost for maintenance due to stop operations and accidents from the operating machines. Therefore, it claims new systems to monitor the operating status and predict the faults of the machines. This research classifies the normal/abnormal status of the machines into 5 levels which are normal-level/abnormal-level/care-level/dangerous-level/fault and develops the new system that predicts faults without stop operation in power plants. We propose the regional segmentation technique in the frequency domain from the data of the operating machines and generate the Peak-codes similar to the Bar-codes, The high efficient and economic operations of the power plants will be achieved by carrying out the pre-maintenance at the care level of 5 levels in the plants. In order to be utilized easily at power plants, we developed the algorithm appling to a notebook computer from signal acquisition to the discrimination.

• Journal of KIISE:Software and Applications
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• v.32 no.11
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• pp.1147-1155
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• 2005

This paper deals with Iris recognition as one of biometric techniques which is applied to identify a person using his/her behavior or congenital characteristics. The Iris of a human eye has a texture that is unique and time invariant for each individual. First, we obtain the feature vector from the 2D Iris pattern having a property of size invariant and using the fuzzy LDA which is further through four types of 2D Gabor wavelet. At the recognition process, we compute the similarity measure based on the correlation values. Here, since we use four different matching values obtained from four different directional Gabor wavelet and select the maximum value, it is possible to minimize the recognition error rate. To show the usefulness of the proposed algorithm, we applied it to a biometric database consisting of 300 Iris Patterns extracted from 50 subjects and finally got more higher than $90\%$ recognition rate.

• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1305-1315
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• 2015

Consider the risk score which is a function of a linear score for the classification models. The AUC optimization method can be applied to estimate the coefficients of linear score. These estimates obtained by this AUC approach method are shown to be better than the maximum likelihood estimators using logistic models under the general situation which does not fit the logistic assumptions. In this work, the VUS and HUM approach methods are suggested by extending AUC approach method for more realistic discrimination and prediction worlds. Some simulation results are obtained with both various distributions of thresholds and three kinds of link functions such as logit, complementary log-log and modified logit functions. It is found that coefficient prediction results by using the VUS and HUM approach methods for multiple categorical classification are equivalent to or better than those by using logistic models with some link functions.

• Journal of Korean Society of Forest Science
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• v.75 no.1
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• pp.32-37
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• 1986

In order to get the fundamental information that could be useful to judge the potentiality of occurrence of rapid shallow landslide in the objective slope, factors selected on Jinhae regions in Korea, where many landslides were caused by heavy rainfall of daily 465 mm and hourly 52mm in August 1979, was carried out through the multiple statistics of quantification method (II) by the electronic computer. The net system with $2{\times}2cm$ unit mesh was overlayed with the contour map of scale 1:5000. 74 meshes of landslides and 119 meshes of non-landslide were sampled out to survey the state of vegetative cover and geomorphological conditions, those were divided into 6 items arid 27 categories. As a result, main factors that would lead to landslide were shown in order of vegetation, slope type, slope position, slope, aspect and numbers of stream. Particularly, coniferous forest of 10 years old, concave slope and foot of mountain were main factors making slope instability. On the contrary, coniferous forest of 20-30 years old, deciduous forest, convex slope and summit contributed to the stable against Landslide. The boundary value between two groups of existence and none of landslides was -0.123, and its prediction was 72%. It was well predicted to divide into two groups of them.

• Journal of Korean Society of Forest Science
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• v.89 no.2
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• pp.256-259
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• 2000

D.B.H., height, crown length, crown width, crown form, crown area, and crown volume of dead and live trees were measured and the discriminant analysis was conducted to assess individual tree risk-rating in the pine forest seriously infested by the pine needle gall midge. Thecodiplosis japonensis. Crown length, crown form, crown area, and crown volume of live tree were significantly higher than those of dead tree, while D.B.H. and tree height were not different significantly. These results represent that the trees with higher and wider crown and larger crown volume have relatively higher probability to survive from the infestation by the pine needle gall midge. Variables selected in the functions of discriminant analysis were crown area, ratio of crown length, crown form, ratio of crown volume to crown area, and ratio of crown width.

• Korean Journal of Culture and Social Issue
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• v.17 no.2
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• pp.175-197
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• 2011

This study aimed to expand and reconstruct the Driving Behavior Determinants' factors in order to confirm the relationship between Driving Behavior Determinants(DBD) and drivers' reckless driving behavior level. To expand the structure of DBD, drivers anger, introversion and type A characteristics were added, which were never considered as related factors in existing DBD studies before. The correlations between the new factors of DBD and reckless driving behavior(includes driver's personal records of driving experiences for the last three years) were verified. A factor analysis result showed us that new DBD questionnaire consists of five factors such as, 'Problem Evading', 'Benefits/Sensation Seeking', 'Anti-personal Anxiety', 'Anti-personal Anger', and 'Aggression'. Also, reckless driving behavior consists of 'Speeding', 'Inexperienced Coping', 'Wild Driving', 'Drunken Driving', and 'Distraction'. The result of correlation between the DBD and reckless driving behavior indicates that inappropriate level of DBD is highly correlated with dangerous driving behavior and strong possibilities of traffic accidents. Based on these results, we might be able to discriminate drivers according to DBD level and predict their reckless driving behavior through a standardization procedure. Futhermore, this will make us to provide drivers differentiated safety education service.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.5
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• pp.453-467
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• 2016

Overall risks that can occur in a shield TBM tunnelling are studied in this paper. Both the potential risk events that may occur during tunnel construction and their causes are identified, and the causal relationship between causes and events is obtained in a systematic way. Risk impact analysis is performed for the potential risk events and ways to mitigate the risks are summarized. Literature surveys as well as interviews with experts were made for this purpose. The potential risk events are classified into eight categories: cuttability reduction, collapse of a tunnel face, ground surface settlement and upheaval, spurts of slurry on the ground, incapability of mucking and excavation, and water leakage. The causes of these risks are categorized into three areas: geological, design and construction management factors. Bayesian Networks (BN) were established to systematically assess a causal relationship between causes and events. The risk impact analysis was performed to evaluate a risk response level by adopting an Analytic Hierarchy Process (AHP) with the consideration of the downtime and cost of measures. Based on the result of the risk impact analysis, the risk events are divided into four risk response levels and these levels are verified by comparing with the actual occurrences of risk events. Measures to mitigate the potential risk events during the design and/or construction stages are also proposed. Result of this research will be of the help to the designers and contractors of TBM tunnelling projects in identifying the potential risks and for preparing a systematic risk management through the evaluation of the risk response level and the migration methods in the design and construction stage.