• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.61-64
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• 2008

Purpose: The analysis of individual eye model designed from clinical demonstration about emmetropia shows that the aberration would be changed by the wave change. Method: The model on the basis of clinical demonstration of eye ball is designed in a form of having 4 refraction surfaces and a constant refractive index. We analyzed designed twelve individual eye model into aberrations changes, as giving changes Fraunhofer lines's six wavelengths. Result: About individual eye model, change in the wavelength of the wavefront aberrations analysis using the Zernike coefficient. This data indicate that the shorter wave is, the more defocus increases and the deviation value of spherical aberration and RMS are widened. Conclusion: As quantity of defocus according to result wavelength change is shorter and shorter, inclination which is similar twelve individual eye model is bigger and bigger and individual eye model majority of cases, little change, and change is shown in part individual eye model is a significant performance degradation can be raised.

• Journal of Korean Society of Transportation
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• v.29 no.3
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• pp.73-82
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• 2011

Recent advancement in traffic surveillance systems has allowed the researchers to obtain more detailed vehicular movement such as individual vehicle trajectory data. Understanding the characteristics of interactions between leading and following vehicles in the traffic flow stream is a backbone for designing and evaluating more sophisticated traffic and vehicle control strategies. This study proposes a methodology for estimating rear-end crash potential, as a probabilistic measure, in real-time based on the analysis of vehicular movements. The methodology presented in this study consists of three components. The first predicts vehicle position and speed every second using a Kalman filtering technique. The second estimates the probability for the vehicle's trajectory to belong to either 'changing lane' or 'going straight'. A binary logistic regression (BLR) is used to model the lane-changing decision of the subject vehicle. The other component calculates crash probability by employing an exponential decay function that uses time-to-collision (TTC) between the subject vehicle and the front vehicle. The result of this study is expected to be adapted in developing traffic control and information systems, in particular, for crash prevention.

• The Korean Journal of Applied Statistics
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• v.26 no.3
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• pp.453-470
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• 2013

In this paper, we consider a Bayesian analysis of the dose-effect relationship of cadmium to evaluate a benchmark dose(BMD). For this purpose, two dose-response curves commonly used in the toxicity study are fitted based on Bayesian methods to the data collected from the scientific literature on cadmium toxicity. Specifically, Bayesian meta-analysis and hierarchical modeling build an overall dose-effect relationship that use a piecewise linear model and Hill model, where the inter-study heterogeneity and inter-individual variability of dose and effect such as gender, age and ethnicity are accounted. Estimation of the unknown parameters is made by using a Markov chain Monte Carlo algorithm based user-friendly software WinBUGS. Benchmark dose estimates are evaluated for various cut-offs and compared with different tested subpopulations with with gender, age and ethnicity based on these two Bayesian hierarchical models.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.139-145
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• 2006

This paper develops pedestrian fatality models capable of producing the probability of pedestrian fatality in collision between vehicles and pedestrians. Probabilistic neural network (PNN) and binary logistic regression (BLR) ave employed in modeling pedestrian fatality pedestrian age, vehicle type, and collision speed obtained from reconstructing collected accidents are used as independent variables in fatality models. One of the nice features of this study is that an iterative sampling technique is used to construct various training and test datasets for the purpose of better performance comparison Statistical comparison considering the variation of model Performances is conducted. The results show that the PNN-based fatality model outperforms the BLR-based model. The models developed in this study that allow us to predict the pedestrian fatality would be useful tools for supporting the derivation of various safety Policies and technologies to enhance Pedestrian safety.

• Journal of The Korean Association of Information Education
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• v.9 no.3
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• pp.397-406
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• 2005

The goal of this research is to prove the efficiency of direct instruction by developing and applying an ICT teaching and learning course for physical education based on a direct instruction model. The curriculum for physical education requires the instructors example and feedback, and sometimes classes may be difficult to conduct due to reasons such as weather conditions. Also, in actual learning, the application of a learning model is inadequate. In these cases, using an ICT teaching and learning course, experts can show examples instead. The learners are provided with individual and suitable feedback and can make it practical for them by slowing down motions, sectional motion learning, and repetitive learning. It can also enhance the sharing of the instructors teaching and learning methods. Therefore, this research recomposed the commonly used direct teaching and learning methods in physical education in order to make it suitable for ICT utilized lessons. It was recomposed in a procedural model and each level was explicated, and in order to materialize this, an ICT teaching and learning course was developed. This was then applied to a Fifth grade class, and its learning effects were analyzed.

• Journal of the Korean Data and Information Science Society
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• v.22 no.3
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• pp.459-466
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• 2011

This article addresses robust Bayesian modeling for meta analysis which derives general conclusion by combining independently performed individual studies. Specifically, we propose hierarchical Bayesian models with unknown variances for meta analysis under priors which are scale mixtures of normal, and thus have tail heavier than that of the normal. For the numerical analysis, we use the Gibbs sampler for calculating Bayesian estimators and illustrate the proposed methods using actual data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.6
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• pp.663-673
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• 2021

Normally, allowable mean overtopping discharge is used as a design parameter for coastal structures. The crest elevation of a structure must ensure wave overtopping discharge within acceptable limits for structural safety and the safety of pedestrians, vehicles, operations, and so on. Some researchers have alternatively proposed using the maximum individual wave overtopping volumes as design criteria during a design storm, since these can provide a better design measure than the mean overtopping rate. This study contributes to the knowledge on maximum individual overtopping volumes in Rayleigh-distributed wave conditions. Two-dimensional physical model tests on typical rubble mound structure geometries were performed, and the new measurement method for individual overtopping was adopted. An empirical formula was proposed to predict the maximum individual overtopping volumes based on the mean overtopping rate, and the reduction effects by the armor crest width on the mean wave overtopping discharge were assessed.

• 한국정보교육학회:학술대회논문집
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• 2006.08a
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• pp.143-148
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• 2006

정보 통신 기술의 발달과 학습자의 다양한 요구에 따라 온라인을 통한 웹기반 학습에 이어 휴대인터넷 (WiBro)과 UMPC (Ultra Mobile PC)를 비롯한 모바일 환경에서의 학습 시대가 열리게 되었다. 본 연구에서는 학습자의 특성을 고려하여 자기 주도적 학습 형태인 모바일 학습에서 학습자의 학습동기를 유발, 지속시키기 위한 방안으로써 Keller의 동기 유발 이론에 기초하여 학생들이 흥미를 잃지 않고 스스로 학습할 수 있도록 모바일 학습에 적합한 새로운 동기 모형을 제시하고자 한다. 본 동기 모형의 특징은 다음과 같다. 첫째, 교사들이 현장에서 이 모형을 바로 사용할 수 있도록 현실적이고 꼭 필요한 절차만 거치도록 하였다. 둘째, 다양한 평가 과정을 절차에 삽입함으로써 학습활동에 대한 보상과 강화를 학습중에 얻도록 하였다. 셋째, 개발된 콘텐츠를 수업안에 바로 적용시킴으로써 자연스러운 수업이 될 수 있도록 구성하였다. 넷째, 개별화에 중점을 두어 자기주도적인 학습이 가능하도록 하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.386-386
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• 2011

다양한 연구 분야에서 강수량, 온도, 습도, 일조량은 연구에 필요한 기후 인자로써 사용되어져 왔다. 외국의 경우 기후 인자들과의 관계를 도출해 내는 연구가 이루어 졌지만 국내의 경우는 이러한 연구가 이루어지지 않고 있다. 본 연구에서는 이러한 인자들과의 관계를 강수-온도-습도-일조량이 연동되어 모의되는 기법을 개발하고자 한다. 기존 국내외 연구결과들은 지수함수식의 형태를 가지는 모형을 이용하여 온도-일조량(radiation), 온도-습도, 습도-일조량, 온도와 강수-일조량과 습도를 개별적으로 추정하는 연구들이 있었다. 그러나 온도, 강수량, 습도, 일조량 등은 기상학적 관점에서 모두 연관성을 가지고 각 변량들에 영향을 주고 있다. 이러한 점에 착안하여 본 연구에서는 4가지 변량들이 가지는 관계를 규명하고 각 변량간의 상관관계뿐만 아니라 4가지 변량이 동시에 상관성을 갖도록 모형을 구축하고자 한다. 일반적으로 각 변량들 간의 확률적인 거동을 동시에 고려할 수 있는 Network 모형이 많이 이용된다. 본 연구에서는 Bayesian Network 모형을 활용하여 4가지 변량 간에 Bayesian Network를 구성하고, 통계적 모형으로 발전시켜 기후변화 연구에 활용하고자 한다. 제안된 방법론에 대한 적합성을 평가하기 위해, 서울지점을 대상으로 온도, 강수, 습도, 일조량 값을 이용하였다. 기후변화에 따른 수문순환모형에서 이들 4가지 변량은 기본 입력자료로 이용되고 있으나, 현재까지는 강수 및 온도를 사용한 모형 개발이 이루어지고 있다. 이러한 점에서 본 연구의 결과는 기후변화에 따른 물순환 변동성을 평가하는 기본 자료로서 활용될 수 있을 것으로 판단된다.

• Journal of Korean Library and Information Science Society
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• v.46 no.4
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• pp.207-226
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• 2015

FRBR and FRAD model, ICP, RDA, NCR Revision are analyzed for the composition of KCR4 Revision. Based on the results, follows are suggested. 1) Entities are divided into work, expression, manifestation, item, person, family, corporate body, concept, object, event, place. 2) Entire cataloging rules are grouped into 'attributes' and 'relationships', and then 'attributes' is divided into attributes describing and access points constructing. 3) Attributes describing is divided into attributes describing of works, expressions, manifestations, items, persons, families, corporate bodies, and arranged as the sequence. 4) Access points constructing is divided into access points constructing of works, expressions, persons, families, corporate bodies, and arranged as the sequence. 5) 'Relationships' is divided into other relationships between group 1 entities, and relationships between persons, families and corporate bodies.