• Journal of Digital Convergence
• /
• v.15 no.2
• /
• pp.335-345
• /
• 2017

It is necessary for an instructor to understand the student's team building behavior for an effective guidance of team activities. In this study, we developed an agent-based computational model for simulating the student's self-controlled behavior. We validated the model by comparing the actual behavior. Through the simulation, we found that the time to stabilization of team formation and the ratio of the students having no team are decreasing as the population of the student increases. However, we also found that over a certain amount of population, the time and the ratio do not show much progress in the difference. The simulation also shows that the more heterogeneity between the students the higher chance of delaying the team formation and increasing the ratio. We expect to use the model as a tool for guiding and supporting students' team activities.

• The Korean Journal of Applied Statistics
• /
• v.24 no.4
• /
• pp.575-586
• /
• 2011

In this paper, we study an asymptotic behavior of the finite-time ruin probability of the compound Poisson model in the case that the initial surplus is large. To compare an exact ruin probability with an approximate one, we place the focus on the exact calculation for the ruin probability when the claim size distribution is regularly varying tailed (i.e. exponential claims and inverse Gaussian claims). We estimate an adjustment coefficient in these examples and show the relationship between the adjustment coefficient and the safety premium. The illustration study shows that as the safety premium increases so does the adjustment coefficient. Larger safety premium means lower "long-term risk", which only stands to reason since higher safety premium means a faster rate of safety premium income to offset claims.

• Communications for Statistical Applications and Methods
• /
• v.19 no.1
• /
• pp.65-75
• /
• 2012

In setting an experimental design for the prediction outside the experimental region (extrapolation design), it is natural for the experimenter to be very careful about the validity of the model for the design because the experimenter is not certain whether the model can be extended beyond the design region or not. In this paper, a hybrid constrained type approach was adopted in dealing model uncertainty as well as the prediction error using the three basic principles available in literature, maxi-min, constrained, and compound design. Furthermore, the effect of the distance of the extrapolation design point from the design region is investigated. A search algorithm was used because the classical exchange algorithm was found to be complex due to the characteristic of the problem.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2004.05b
• /
• pp.731-736
• /
• 2004

강우-유출과정의 수문학적 현상을 보다 정확히 분석하고 예측하는 기법으로 강우에 의한 유출의 반응을 나타내는 지체시간, 도달시간 등 수문학적 반응시간을 유역의 지형형태학적 인자들과 연계하는 방법이 많이 이용되고 있다. 이에 본 연구에서는 Clark방법과 지형형태학적 순간단위도(GIUH)를 이용하여 계측유역의 강우-유출반응을 모의하였고, 이를 관측된 값과 비교하여 미계측유역의 적용성 여부를 검토해보았다. 대상 유역의 하상지형인자 및 지형형태학적 특성은 Arc-View를 이용하여 구하였으며, 이를 기존의 문헌자료와 비교해보았다. Clark방법의 매개변수의 결정에 있어서 시간-면적곡선은 HEC-1의 무차원 식을 이용하였고, 도달시간은 Kirpich 공식을 이용하여 구하였으며, 저류상수는 Clark방법에 의해 추정된 순간단위도의 첨두유량이 Horton의 차수비의 함수로 구한 철두유량과 같아지는 값으로 결정하였다. 본 연구는 전적비교를 출구점으로하는 유역면적 $8.5km^2$인 설마천을 대상유역으로 하였으며, 모의된 강우-유출반응과 비교하기 위해 사용된 강우사상은 2002년의 8월 4일과 2002년 10월 6일의 10분 단위 우량이다. Clark방법과 GIUH를 이용하여 모의한 유출곡선과 관측된 유출곡선을 비교해본 결과 첨두유량은 8월의 강우사상 때는 $21\%$크게, 10월의 강우사상 때는 $35\%$작게 나타났다. 첨두시간은 모의된 경우가 각각 10분, 20분 빨리 도달하였다. 또한 이러한 결과는 유역의 도달시긴에 가장 민감하게 반응함을 알 수 있었다. 따라서, 유역의 도달시간 산정에 주의를 요한다면 프랙탈 차원이 유사한 미계측유역의 수문곡선 산정에 있어서 Clark방법과 GIUH를 이용하는 방법도 유용하다고 사료된다. 주는 각 수문인자 중 강우시간분포와 유효우량 산정방법 그리고 유출모형에 대해 자자 검토하였으며, 최종적으로 면적에 따른 임계지속기간과 유출량의 변화를 검토해 보았다.이를 각각의 경우의 해석해 결과와 비교${\cdot}$분석하였다. 후방추적 퍼프모형은 전방추적 퍼프모형에 비하여 사용된 퍼프수와 관계없이 작은 오차를 발생하였으며, 전체적으로 퍼프 모형이 입자모형보다는 훨씬 적은 수의 계산을 통해서도 작은 오차를 나타낼 수 있다는 것을 알 수 있었다. 그러나 Gaussian 분포를 갖는 퍼프모형은 전단흐름에서의 긴 유선형 농도분포를 모의할 수 없었고, 이에 관한 오차는 전단계수가 증가함에 따라 비선형적으로 증가하였다. 향후, 보다 다양한 흐름영역에서 장${\cdot}$단점 분석 및 오차해석을 수행한 후에 각각의 Lagrangian 모형의 장점만을 갖는 모형결합 방법을 제시할 수 있을 것으로 판단된다.mm/$m^{2}$로 감소한 소견을 보였다. 승모판 성형술은 전 승모판엽 탈출증이 있는 두 환아에서 동시에 시행하였다. 수술 후 1년 내 시행한 심초음파에서 모든 환아에서 단지 경등도 이하의 승모판 폐쇄 부전 소견을 보였다. 수술 후 조기 사망은 없었으며, 합병증으로는 유미흉이 한 명에서 있었다. 술 후 10개월째 허혈성 확장성 심근증이 호전되지 않아 Dor 술식을 시행한 후 사망한 예를 제외한 나머지 6명은 특이 증상 없이 정상 생활 중이다 결론: 좌관상동맥 페동맥이상 기시증은 드물기는 하나, 영유아기에 심근경색 및 허혈성 심근증 또는 선천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다. 그러나 진단 즉시 직접 좌관상동맥-대동맥 이식술로 수술적 교정을 해줌으로써 좋은 성적을 기대할 수 있음을 보여주었다.특히 교사들이 중요하

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.2
• /
• pp.719-727
• /
• 2013

Four-step travel-demand modeling based on a trip-level has been widely used over many decades. However, there has been a wide variance between forecasted- and real-travel demands, which leads less reliable on the model implications. A primary reason is that person's real travel behavior is not properly captured throughout the model developments. An activity-based modeling (ABM) approach was proposed and developed toward increasing the accuracy and reality of person's travel behavior in the U.S. since 1990', and stands as a good alternative to replace the existing trip-based approach. The paper contributes to the understanding of how the ABM approaches are dissimilar to the trip-based modeling approach in terms of estimation units, estimation process, their pros and cons and etc. We examined three activity-based travel demand model systems (DaySim, CT-Ramp, and CEMDAP) that are most commonly applied by many MPOs (Metropolitan Planning Organization). We found that the ABM approach can effectively explain multi-dimensional travel decision-makings and be expected to increase the predictive accuracy. Overall, the ABM approach can be a good substitute for the existing travel-demand methods having unreliable forecasts.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.8
• /
• pp.269-278
• /
• 2021

This study was conducted to develop a learning competency scales customized for learning programs conducted by Center for Teaching & Learning at A University. To achieve this purpose, a preliminary study was set up, which consists of three competency groups (basic competency, intensity competency, application competency) and 13 learning competency factors through a review of previous studies. In order to verify the reliability and validity of the provisional learning competency scales, an online survey was conducted on A university students in September 2020, The collected questionnaire data were organized and exploratory factor analysis and confirmatory factor analysis were conducted. As a result of exploratory factor analysis, 13 learning competency was reduced to 10 as the three competency groups were maintained. As a result of the confirmatory factor analysis, the model was found to be good, Also, as a result of analyzing the reliability of the confirmed learning competency factors, all 10 factors showed a good level of .7 or more. The learning competency scales developed through this study can be used as basic data for performance evaluation and development of new programs of CTL learning program.

• Journal of the Korea Convergence Society
• /
• v.9 no.10
• /
• pp.393-406
• /
• 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 the Korea institute for structural maintenance and inspection
• /
• v.18 no.5
• /
• pp.96-106
• /
• 2014

The increased vibration level of the railway bridge could make significant noise and, also, cause structural damages such as fatigue cracks. Related to these subjects, a spherical elastomeric bridge bearing, which is layered by hemispherical rubber and steel plates, was investigated in terms of its vibration performance. Several different shape factors could be considered by changing the curvature of hemispherical surface and size in rubber and steel plate thicknesses in the manufacturing stage. The performance of the spherical elastomeric bearing for the reduction in vibration was compared with that of the conventional bearing by performing vibration experiments on a scale-downed model. The rubber material characteristics and spherical shape are found to be important parameters in reducing the bridge vibration.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.6
• /
• pp.148-156
• /
• 2018

The integrity assessment of the bridge behavior is generalized by field data of a static load-deformation curve and dynamic properties such as impact factors and natural frequencies. Evaluating it with numerical analysis is a reasonable method. The results of the mockup test and the numerical analysis are corresponded with each other since the behavior of service load proceeds in elastic region. In case of the dynamic behavior of structure, especially for the analysis of vibration, the result of the mockup test differs from the result of numerical analysis a little due to the geometric shape and non-homogeneous materials. In order to converge on these tolerances, this study suggested several numerical models, analyzed the sensitivity and finally offered a practical modeling method for the estimation of bridge on the basis of the result of mockup test. Based on the model substituted concrete section for strands section, the natural frequency of the model composed with axial stiffness of strands or the model applied the modified modulus of elasticity was closest with the result of the mockup test.

• Korean Journal of Poultry Science
• /
• v.21 no.1
• /
• pp.21-34
• /
• 1994

The objective of this study was to develop a user-friendly computer model for economic analysis on the commercial egg production that could help the egg farmer make managerial diagnosis and rational decision in the changing environment. To raise the adequacy of the model, the program was run for every sample and adjusted to fit the data. The model, programmed with Microsoft QuickBASIC, was a user-friendly computer program in supporting the Korean language. The basic analytical tool used in the study was an engineering-type computerized simulation model which incorporates a cost-benefit analysis of a full-time egg farmer. The computer model developed in this study may be the powerful analytical tool used to evaluate both a managerial decision whether to alter the production system and its impact on production, costs, revenue, and profits. Ultimately, the program is expected to enable the egg farmer to make managerial planning and diagnosis. The program can also calculate the values of economic variables at user-chosen incremental values of market eggs and feed prices. It provides the information on the profit and cost. This may lead the egg farmer, by allowing to establish the best managerial strategy, to increase the profit aor to lessen the cost. The results of this study could be utilized in the evaluation and improvement of the management. It also may be utilized for the researchers and guiding farmers in collecting and analyzing the data on the laying hen. In particular, such a program would be potentially useful to researchers who wish to quickly estimate profits associated with various laying hen treatments. The program could also benefit the egg farmer interested in making managerial decisions based on either current or predicted market conditions. The model would make the egg farmer respond actively to the information-oriented society by promoting to use personal computer.