• Communications for Statistical Applications and Methods
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• 제15권5호
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• pp.783-791
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• 2008

Estimation procedure of the finite population proportion and distribution function is considered. Based on a logistic regression model, an approximately model- optimal estimator is defined and conditions for the estimator to be design-consistent are given. Simulation study shows that the model-optimal design-consistent estimator defined under a logistic regression model performs well in estimating the finite population distribution function.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1902-1907
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• 2007

This paper suggests improvements in travel cost function of transit assignment model by analysing existing model. Two types of travel cost function are widely used for congested public networks. The one is used for strictly restricting public transport capacity. Another is non-decreasing function such as BPR function. In this paper, we analyse two types of travel cost function in case of intercity rail. The characteristics of intercity rail are different from those of public transit in urban area. Therefore travel cost function must be differently applied in each case.

• 디지털융복합연구
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• 제13권1호
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• pp.449-454
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• 2015

본 연구는 소셜게임의 사회적 기능과 개발모델에 관한 선행요인과 결과요인 및 개발 모델을 제안 분석하는 것을 목적으로 한다. 따라서 본 연구는 소셜게임 사회적 기능에 영향을 미칠 수 있는 선행변수들을 관련이론 분석과 선행연구를 통해 살펴보고, 소셜게임의 사회적 기능 개발 모델을 제시하고 분석하였다. 소셜게임의 사회적 기능 모델을 정서적 유대감, 개방적커뮤니케이션, 공동체감, 상호작용 집중에서 설명되는 항목들을 구체화하여 사회적 기능 향상 척도를 도출하였고, 다양한 소셜네트워크서비스 및 소셜게임 관련이론을 바탕으로 소셜게임 사회적 기능향상 요소를 입증하여 소셜게임 개발 모델를 제시하였다.

• 대한간호학회지
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• 제23권4호
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• pp.678-693
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• 1993

The purposes of this study were to describe the level of vision and hearing impairments, depression and functional capacity, among Korean institutionalized elderly and to examine the relation-ship between sensory impairments, depression, and functional capacity in these people. The final pupose was to test the cognitive function path model using sensory competencies as predictors. A convenience sample of thirty nine male and 90 female subjects with a mean age of 80.5 were the subjects of this study. The subjects were tested for cognitive function, and vision and hearing impairments. Physical function and social function were measured by observation of designated task performance by the subjects. Their level of de-pression was measured using a Geriatric Depression Scale administered through an interview. Individual subjective ratings of hearing and vision were marked by the subjects, on a ladder scale. The results of the study showed that 48.8% of the subjects had a hearing impairment, 63.5% had a vision impairement, and 36.4% had both a vision and hearing impairement. The four sensory groups (no sensory impairement, hearing impairement, vision impairement, hearing and vision impairement) were tested for differences in depression, physical function, social behavior and cognitive function. The only significant difference that was found was in cognitive function, between the no sensory impairement group and the hearing and vision impairement group(F=3.25, P<.05), Subjective ratings of hearing showed a significant correlation with cognitive function(r=.34, p<.001) and with social behavior(r=.31, p<.001). There was no correlation between subjective vision ratings and cognitive function or social behavior. However there was a significant correlation between vision and hearing(r=.49, p<.001). There was also a significant negative correlation between age and vision(r=-.21, p<.01) and between age and hear-ing(r=-.34, p<.001). There was a significant correlation between depression and physical function (r=-.32, p<.001) but there was no correlation between depression and cognitive function or social behavior. Based on the literature review and the result, this study, a path model of sensory competence-> cognitive function- >social behavior was developed and tested : Perceived vision and perceived hearing were the exogenous variahles and cognitive function and social behavior were the endogeneous variables in the model. The path analysis result demonstrated an accept-able fit (GFI=.997, AGFI=.972, X$^2$=.72 (p=.396), RMSR=.019) between the data and the model. There was a significant direct effect($\beta$=.38) of perceived hearing on cognitive function. There was a significant direct effect ($\beta$=.32) of cognitive function on social behavior. The total effect of hearing on social behavior was $\beta$=.32 including the indirect effect ($\beta$=.12) . However perceived vsion had little effect ($\beta$=-.08) on cognitive function. The result of path analysis confirms that hearing levels influence cognitive function, and both hearing and cognitive function levels influence social behavior. However, vision has little effect on cognitive function or on social behavior. For the next study, a combined model of the pre viously developed environment - >depression- > physical and social function model, and the present cognitive function model, should be tested to further refine the functional capacity model. There also a need for longitudinal study of functional capacity and sencory competence in order to better understand how declining sensory competence influences functional capacity and how it effects in-creasing dependency and nursing needs in the elderly.

• 해양환경안전학회지
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• 제21권3호
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• pp.253-258
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• 2015

The purpose of this study is to find suitable probability distribution function of complex distribution data like multimodal. Normal distribution is broadly used to assume probability distribution function. However, complex distribution data like multimodal are very hard to be estimated by using normal distribution function only, and there might be errors when other distribution functions including normal distribution function are used. In this study, we experimented to find fit probability distribution function in multimodal area, by using AIS(Automatic Identification System) observation data gathered in Mokpo port for a year of 2013. By using chi-squared statistic, gaussian mixture model(GMM) is the fittest model rather than other distribution functions, such as extreme value, generalized extreme value, logistic, and normal distribution. GMM was found to the fit model regard to multimodal data of maritime traffic flow distribution. Probability density function for collision probability and traffic flow distribution will be calculated much precisely in the future.

• International Journal of Precision Engineering and Manufacturing
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• 제7권1호
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• pp.47-50
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• 2006

An active contour model has been used to detect the edges in a still image. In order to apply the active contour model to edge detection, the energy function which consists of internal, external and image energies should be defined. After defining the energy function, the edge of an object is detected through minimization of the value of the energy function. In this paper, the modified internal energy function is proposed to improve the convergence of the energy function when the active contour model is applied to the tracking of deformable objects using the greedy algorithm. In order to show the performance of the proposed energy function, experiments were carried out for the still and animated images.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제16권4호
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• pp.262-269
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• 2016

In this paper, we propose a novel dynamical love model of Romeo and Juliet, which has an external force with a fuzzy membership function. The external force used in the model has the characteristics of a Gaussian function. The chaotic behavior in the model is demonstrated using time series and phase portraits.

• 한국시뮬레이션학회논문지
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• 제21권1호
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• pp.27-34
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• 2012

본 논문의 목적은 복잡한 군수지원시스템의 모델링과 시뮬레이션을 위한 방법론을 제안하는 것이다. 제안하는 군수지원시스템 시뮬레이션 모델을 구성하는 요소들은 세 가지가 있다 : Logistics force agent(static model), Military supplies transport manager(function model), Military supplies state manager(dynamic model). Logistics force agent는 main function agent와function agent로 구성된다. Function agent가 다른 Logistics force agent에도 적용할 수 있도록 설계되었으며, 이는 에이전트의 높은 조합성과 재사용성을 가진다. Military supplies transport manager는 보급로에 대한 정보를 가지며 military supplies state manager로부터 받은 결정변수를 기반으로 보급로를 결정하고 군수품을 수송하는 역할을 하는 에이전트이다. Military supplies state manager는 군수품 보급을 요청받고 보급량, 우선순위 따위의 결정 변수를 military supplies transport manager에게 알려주는 역할을 한다. 본 논문에서는 군수 시뮬레이션 모델의 설계를 위해 Discrete Event Systems Specification(DEVS) formalism을 이용하였다.

• Journal of the Korean Wood Science and Technology
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• 제33권5호통권133호
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• pp.29-37
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• 2005

A previous study verified that the SIRT (simultaneous iterative reconstruction technique) method is more efficient than the back-projection method as a CT algorithm for wood. However, it was expected that the determination of the initial model function of the SIRT method would influence the quality of CT image. Therefore, in this study, we intended to develop a technique that could be used to determine an adequate initial model function. For this purpose, we proposed several techniques, and for each technique we examined the effects of the initial model function on the average errors and the CT image at each iteration. Through this study, it was shown that the average error was decreased and the image quality was improved using the proposed techniques. This tendency was most pronounced when the back-projection method was used to determine the initial model function. From the results of this study, we drew the following conclusions: 1) The initial model function of the SIRT method should be determined with careful attention, and 2) the back-projection method efficiently determines the initial model function of the SIRT method.

• Journal of Information Technology Applications and Management
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• 제25권2호
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• pp.109-116
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• 2018

In this study, we was compared the reliability performance of the software reliability model, which applied the Goel-Okumoto model developed using the exponential distribution, to the logarithmic function modifying the intensity function and the Rayleigh form. As a result, the log-type model is relatively smaller in the mean squared error compared to the Rayleigh model and the Goel-Okumoto model. The logarithmic model is more efficient because of the determination coefficient is relatively higher than the Goel-Okumoto model. The estimated determination coefficient of the proposed model was estimated to be more than 80% which is a useful model in the field of software reliability. Reliability has been shown to be relatively higher in the log-type model than the Rayleigh model and the Goel-Okumoto model as the mission time has elapsed. Through this study, software designer and users can identify the software failure characteristics using mean square error, decision coefficient. The confidence interval can be used as a basic guideline when applying the intensity function that reflects the characteristics of the lifetime distribution.