• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.4
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• pp.329-337
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• 1993

It has been acknowledged as an important problem to maintain identity or compatibility among experimental laboratory data obtained separately in different wave flumes. The data quality mainly depends on how long the target waves can be realized in a flume without distortions. In the present paper a control circuit is devised in the form of multiple feed-back operations to attain a complete equality of the intended waves and the realized waves. The analysis of the circuit gives an algorithm which can be easily adapted to a small computer controlling wave making hardwares. As a main feature of the algorithm, a numerical filter with wave absorbing capability is presented. The filter is discretely realized so that the discrete input matches to the output directly, hence applicable even to nondeterministic input Through several example analyses, the algorithm proved its accuracy, being effective to both regular and irregular reflected waves.

• The Korean Journal of Applied Statistics
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• v.24 no.5
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• pp.915-930
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• 2011

There are a variety of methods to model game results and many methods exist for the case of paired comparison data. Among them, the Bradley-Terry model is the most widely used to derive a latent preference scale from paired comparison data. It has been applied in a variety of fields in psychology and related disciplines. We applied this model to the data of Korean Baseball League. It shows that the loglinear Bradley-Terry model of defensive rate and save is optimal in terms of AIC. Also some categorical characteristics, such as east team and west team, existence of golden glove winning players, team(s) with seasonal pitching leader, and team(s) with home advantage, influenced the game result significantly. As a result, the suggested models can be further utilized to predict future game results.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.1
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• pp.112-119
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• 2010

This paper defines the probability models for determining the disparity map given stereo images and derives the methods for solving the problem, which is proven to be equivalent to an energy-based stereo matching. Under the assumptions the difference between the pixel on the left image and the corresponding pixel on the right image and the difference between the disparities of the neighboring pixels are exponentially distributed, a recursive approach for estimating the MRF regularizing parameter is proposed. Usually energy-based stereo matching methods are so sensitive to the parameter that it should be carefully determined. The proposed method alternates between estimating the parameter with the intermediate disparity map and estimating the disparity map with the estimated parameter, after computing it with random initial parameter. It is shown that the parameter estimated by the proposed method converges to the optimum and its performance can be improved significantly by adjusting the parameter and modifying the energy term.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.393-406
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• 2018

The depression and anxiety are the most popular mental disorders and not easy to distinguish because of their lots of similarities in the diagnostic criteria, related theories, and clinical symptoms. In this article, we developed the affect scale for distinguishable diagnosis, utilized the relationships between the Positive and Negative affect, and the depression and anxiety. We made up the seed scale of the items which selected by partial correlation, and set the scoring up by multiple regression method. The Multi-dimentional affect scale is reliable and working similarly as the scales used before, but less correlated to each other. We conclude that the affect scale achieved the diagnosis for distinguish between depression and anxiety. Our suggestions for the further study are to redeem the cultural differences, modify by the elaborate methods, and validate by the actual clinical data.

• Journal of Radiation Protection and Research
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• v.22 no.4
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• pp.289-298
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• 1997

Time-consuming experiments have been required in the development of neutron moisture gauge to induce a relation between the water content in soil and the neutron counts. Applying a monte carlo computer code to simulate the experiments of neutron moisture gauging may contribute to reduce time and efforts for experiments and produce a calibration equation which is more applicable to soil in general. In this study MCNP4A, a monte carlo computer code, was employed to simulate soil experiments and the simulated results were compared with experimental ones. The comparative study showed that MCNP4A is applicable to simulate the experiments and calibration equation can be obtained through simulations. Effects of dry density changes were also studied.

• Geophysics and Geophysical Exploration
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• v.1 no.3
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• pp.170-175
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• 1998

A systematic methodology is developed for the prediction of the lithology using electrofacies classification from wireline log data. Multivariate statistical techniques are adopted to segment well log measurements and group the segments into electrofacies types. To consider corresponding contribution of each log and reduce the computational dimension, multivariate logs are transformed into a single variable through principal components analysis. Resultant principal components logs are segmented using the statistical zonation method to enhance the quality and efficiency of the interpreted results. Hierarchical cluster analysis is then used to group the segments into electrofacies. Optimal number of groups is determined on the basis of the ratio of within-group variance to total variance and core data. This technique is applied to the wells in the Korea Continental Shelf. The results of field application demonstrate that the prediction of lithology based on the electrofacies classification works well with reliability to the core and cutting data. This methodology for electrofacies determination can be used to define reservoir characterization which is helpful to the reservoir management.

• Korea journal of population studies
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• v.15 no.2
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• pp.104-124
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• 1992

형제수, 출산순위, 출산터울, 모성의 출산시 연령 등 가족형성 양상은 아동의 신체적 발육 성장 및 지능발달과 강한 관련성을 보여 왔음이 세계 여러나라 아동을 대상으로 수행된 연구에서 보고되었다. 본 연구는 형제수와 출산순위, 그리고 출산시 모성의 연령은 아동의 신체적 지능적 발달과는 역상관관계를, 출산터울의 길이는 순상관관계를 나타낼 것이라는 가설을 증명하고자 1984년 한국중학생 1,2,3학년 약 46,000명을 대상으로 수행되었다. 지역별 그리고 사회경제적 상태별 비교를 위하여 서울시 고소득층이 주로 거주하는 학구내의 중학교와 저소득층이 거주하는 학구내 중학교 각각 5개를 선정하고 강원도내 전형적 농촌의 중학교 12개를 선정하여 신장, 체중, 좌고, 혈구용적 지능지수를 측정하였다. 이들 측정치들의 평균은 학부모와 담임선생님의 도움으로 작성된 가족형성 변수별로 비교되었으며 다중 희귀분석과 부분상관분석으로 연관성의 통계적 유의성을 검정하였다. 동일연령의 신체적 발육성장 지표들은 도시의 고소득지역 아동들이 가장 우수했으며 다음이 도시저소득 지역 아동이었고 농촌아동이 가장 빈약하였다. 남녀별 신체적 발육지표들의 차이는 연령이 많을수록 더 현저했으며 연령별 지역별 차이는 남학생에게서 더 두드러졌다. 평균 지능지수는 도시고소득지역 남학생들이 월등히 높아 114.8인데 비해 도시저소득지역 남학생들은 106.1, 그리고 농촌 남학생들은 105.3이었다. 남학생보다는 여학생의 지능지수가 낮았는데 이것은 대만 아동들도 여학생이 모든 연령에서 남학생보다 낮았다는 보고와 일치하였다. 한편 도시저소득지역과 농총지역 학생들은 남녀모두 평균지능지수가 비슷하였다. 가족형성변수들은 혼란변수들은 모든 제어했을 경우에도 아동들의 신체적 지능적 발달에 독립적으로 영향을 미쳤다. 발육지표중에 지능지수와 형제수가 가장 가족형성 변수들과의 연관성이 강했다.

• Journal of Korean Academy of Nursing
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• v.50 no.4
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• pp.621-630
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• 2020

Purpose: This study was aimed to evaluate the external validity of a carbapenem-resistant Enterobacteriaceae (CRE) acquisition risk prediction model (the CREP-model) in a medium-sized hospital. Methods: This retrospective cohort study included 613 patients (CRE group: 69, no-CRE group: 544) admitted to the intensive care units of a 453-beds secondary referral general hospital from March 1, 2017 to September 30, 2019 in South Korea. The performance of the CREP-model was analyzed with calibration, discrimination, and clinical usefulness. Results: The results showed that those higher in age had lower presence of multidrug resistant organisms (MDROs), cephalosporin use ≥ 15 days, Acute Physiology and Chronic Health Evaluation II (APACHE II) score ≥ 21 points, and lower CRE acquisition rates than those of CREP-model development subjects. The calibration-in-the-large was 0.12 (95% CI: - 0.16~0.39), while the calibration slope was 0.87 (95% CI: 0.63~1.12), and the concordance statistic was .71 (95% CI: .63~.78). At the predicted risk of .10, the sensitivity, specificity, and correct classification rates were 43.5%, 84.2%, and 79.6%, respectively. The net true positive according to the CREP-model were 3 per 100 subjects. After adjusting the predictors' cutting points, the concordance statistic increased to .84 (95% CI: .79~.89), and the sensitivity and net true positive was improved to 75.4%. and 6 per 100 subjects, respectively. Conclusion: The CREP-model's discrimination and clinical usefulness are low in a medium sized general hospital but are improved after adjusting for the predictors. Therefore, we suggest that institutions should only use the CREP-model after assessing the distribution of the predictors and adjusting their cutting points.

• Journal of Korea Port Economic Association
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• v.27 no.2
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• pp.85-110
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• 2011

The purpose of this study is to evaluate the social costs of inland trucking and maritime transport between Kwangyang Port in Korea and the Great Lakes in US. Also, this study compares these social costs each other, and finds the way how to internalize them for the efficiencies of national logistics policies. This study uses the Contingent Valuation Method to evaluate the social costs for the two transport modes in each country. The final result is that the social cost difference between inland trucking and maritime transport around US Great Lakes area is not so significant that there are not many chances to enhance the maritime transport in the region. However, in case of Korea, there is significant difference in social costs between the two transport modes, so that Korea government may have a lot of chances to improve the seaborne trade by way of various internalization policies.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.2
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• pp.199-209
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• 1995

From the results of model tests, statistical regression analysis of EHP estimation based on hull form parameters is adopted in this study. From this result, the method for estimation of EHP at the initial design stage of fishing boats is developed. This method is applied to four standard fishing boats with chine lines and two standard fishing boats with round bottom. The EHP's are estimated and compared to experimental results. In the case of six fishing boats, the estimated EHP corresponds well and approximates well with experimental results through out all the range tested. From these results it can be concluded that this numerical method is very efficient in estimating EHP of fishing boats having chine line and round bottom. Therefore, by applying the proposed method to design of fishing boats, we can improve the resistance characteristics. Further, this method can contribute to reduction of design time and thus down the total expenses.