• 한국철도학회논문집
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• 제7권3호
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• pp.180-185
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• 2004

The present study investigates the effect of fire growth model on fire development characteristics in a carriage. The parallel processing version of FDS code is used to simulate the fire driven flow in a carriage and two types of fire growth model which are flame spread model and t$^2$ model are examined for the same geometrical condition. The heat release rates(HRR) of both model are similar each other until 30 s after ignition, but the flame spread model predicts 5 times higher than those of the t$^2$ fire model during the quasi-steady fire period. Maximum heat release rate in the case of flame spread model reaches about to 12 MW at 100 s after fire ignition. Also, various database of fire properties for combustible materials and more elaborate combustion model considering the flame spreading phenomena are required for better predictions of fire development characteristics using numerical simulation.

• 지역연구
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• 제14권2호
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• pp.35-50
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• 1998

This paper examines the determinants of imbalanced regional development in Korea during the period of 1985-1995. The review of previous analytical techniques have been used to analyze the determinants of disparities in regional development of disparities in regional development, but few has applied the regression technique which reduces a bias due to heterogeneity across region. The results of the study show that Kmenta model with per capita GRDP as dependent variable can reduce the heterogeneity bias in regional development and can minimize the statical errors in estimation and interpretation of the coefficients of the explanatory variables. According to the results of Kmenta model, urban infrastructure such as roads, information and communication facilities are major causes of regional disparity over the period of 1985-1995. The results of the study also indicate that local government should devote their policy efforts to identify and utilize the unique soci-economic characteristics of each locality in the process of regional development.

• 한국산업융합학회 논문집
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• 제21권6호
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• pp.409-418
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• 2018

In this study, experiments were carried out after fabricating and installing a physical model considering the size of the prototype. In the model test, the number of struts placed on the wall and the applied acceleration were selected as test variables. Two different types of waves, long-period and short-period, were applied with magnitudes of 0.05g, 0.1g, 0.2g, and 0.3g. Measured are displacements at specified points. As a result of the analysis, displacement exceeding the allowable displacement of the wall occurred at an acceleration greater than 0.05g to 0.1g depending on the seismic waves applied. Therefore guidelines have to be established through further studies for aseismic design of earth retaining walls.

• 한국경영과학회지
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• 제9권2호
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• pp.15-22
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• 1984

A deterministic multiproduct, facility-in series multiperiod production planning model is analyzed, where each period demand for the product of a facility appear in a fixed proportion of that for the product of the immediately following facility. The model considers concave production and inventory costs, which can depend upon the production in different facilities. No backlogging is allowed. It is shown that the model is represented via a single source network, which facilitates development of efficient dynamic programming algorithms for computing the optimal production schedule.

• 생태와환경
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• 제41권1호
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• pp.43-53
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• 2008

본 연구의 목적은 분포형 수문모형인 TOPMODEL을 이용하여 산림유역의 홍수수문곡선을 추정하는 것이다. 이를 위하여 유역면적 58.3ha의 명성유역을 선정하였으며, 대상유역에 대하여 강우량과 유출량을 측정하였다. Monte Carlo기법을 이용하여 강우사상별로 최적의 매개 변수 조합을 구하고, 매개변수별 모의기간에 대한 평균값을 적용하여 매개변수를 결정하였다. 1997년에 측정된 6개의 강우-유출량 자료를 이용하여 매개변수 보정을 실시하였으며, $1998\sim1999$년에 측정된 8개의 강우-유출량 자료를 이용하여 모형의 검증을 실시하였다. 보정기간에 대한 유출량 추정 오차는 $-2.74\sim1.81%$의 범위를 보였으며, 모형 효율(E)은 평균 0.92이었다. 6개의 강우사상에 대하여 실측된 평균 첨두유량은 $0.324m^3\;s^{-1}$이었으며, 이에 대한 추정치는 $0.295m^3\;s^{-1}$로 모의되었다. 강우 사상별 첨두유량의 오차범위는 $-27.65\sim-1.13%$로 나타났으며, 이는 강우특성 및 선행강우조건에 영향을 받은 것으로 판단된다. 검증기간에 대하여 각 강우사상별 모형효율(E)의 평균값은 0.92로 나타났다. 첨두유량의 실측값은 평균적으로 $0.087m^3\;s^{-1}$이었으며, 추정된 첨두유량의 평균은 $0.090m^3\;s^{-1}$로 나타났다. 첨두시간은 보정기간에 대하여는 관측값과 모의값의 평균이 각각 18.3 hrs와 11.0 hrs이었으며, 검증기간에 대하여는 각각 16.6hrs와 13.5 hrs이었다.

• 대한토목학회논문집
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• 제10권2호
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• pp.59-65
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• 1990

3차원 비정상류모형을 사용하여 출도대지(出島台地)의 소유역에 있어서 인위적및 자연적 요인이 지하수유동에 미치는 영향에 대하여 고찰하였다. 3차원 비정상류모형의 검정을 위하여, 모형에 의한 수치해석해와 Theis의 해석해를 비교한 결과 서로 좋은 대응을 나타내었다. 모의발생은 용수로(用水路)를 통하여 관개가 시작되는 5월 1일부터 30일간 행하였다. 지하수 유동양상을 포텐샬도로 나타내었으며 그에 대한 고찰이 있었다. 본 해석으로 부터 인위적 영향을 받는 지역의 지하수유동계를 해석하기 위해서는 3차원 비정상류모형이 유용하다고 사료되었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권7호
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• pp.3018-3040
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• 2018

The mobility model is one of the most important factors that impacts the evaluation of any transportation vehicular networking protocols via simulations. However, to obtain a realistic mobility model in the dynamic urban environment is a very challenging task. Several studies extract mobility models from large-scale real data sets (mostly taxi GPS data) in recent years, but they do not consider the statuses of taxi, which is an important factor affected taxi's mobility. In this paper, we discover three simple observations related to the taxi statuses via mining of real taxi trajectories: (1) the behavior of taxi will be influenced by the statuses, (2) the macroscopic movement is related with different geographic features in corresponding status, and (3) the taxi load/drop events are varied with time period. Based on these three observations, a novel taxi mobility model (T-START) is proposed with respect to taxi statuses, geographic region and time period. The simulation results illustrate that proposed mobility model has a good approximation with reality in trajectory samples and distribution of nodes in four typical time periods.

• 한국산업융합학회 논문집
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• 제23권2_2호
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• pp.245-254
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• 2020

This study investigated the so far little-researched characteristics of the behaviors of rock slopes at the time of an earthquake. For the selection of the rock block, a proper model was formed by applying the similarity in consideration of the roughness and strength of the rock slope(10m) on the site, and shaking table tests were carried out according to seismic excitement acceleration, and seismic waves. In the case of the inclination angle of the joint plane of 20°, the long period wave at 0.3g or more at the time of the seismic excitement surpassed the length of 100mm, the permissible displacement (0.01H, H:slope height), which brought about the collapse of the rock; the short period wave surpassed the permissible displacement at 0.1g, which caused the collapse of the slope. The rock slope was close to a rigid block and a structure more vulnerable to the long period wave than to the short period wave. It collapsed in the short period wave even at the seismic amplitude smaller than the maximum design acceleration in Korea.

• 대한가정학회지
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• 제32권5호
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• pp.55-66
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• 1994

The aim of this study is to propose the reasonable method of evaluation on the value of the life-time household work. for homemaker claim her share in the matrimonial property in relation to her life-time household work and to provide the basic data to measuring proper compensation for homemaker and calculating of the donation tax and inheritance tax amount. Tom compare the difference of the method of evaluation on the value of the life-time household work is evaluted by three methods: the model of the life-time household work which is reflected major variables in the FLC frame work marital stage, total marital period. The major findings are as follows: 1) Among the three evaluation me？ The method of Total marital period is evaluatied the lowest value of the life-time household work. 2) The evaluation method of marital stage is more resonable method than the method of total marital period habe a convenience of evaluation but it dos'nt reflected major variables which influence the value of life-time household work. 3) the most resonable method of evaluation on the value of the life-time household work is revealed the model of the life-time household work which is reflected major variables in the FLC frame work the age of first and last offspring marital period.

• 한국대기환경학회지
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• 제33권1호
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• pp.11-18
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• 2017

The performance of a modeling system consisting of WRF model v3.3 and CMAQ model v4.7.1 for forecasting $PM_{2.5}$ concentrations were evaluated during the period May 2012 through December 2014. Twenty-four hour averages of $PM_{2.5}$ and its major components obtained through filter sampling at the Bulgwang intensive measurement station were used for comparison. The mean predicted $PM_{2.5}$ concentration over the entire period was 68% of the mean measured value. Predicted concentrations for major components were underestimated except for $NO_3{^-}$. The model performance for $PM_{2.5}$ generally tended to degrade with increasing the concentration level. However, the mean fractional bias (MFB) for high concentration above the $80^{th}$ percentile fell within the criteria, the level of accuracy acceptable for standard model applications. Among three bias correction methods, the ratio adjustment was generally most effective in improving the performance. Albeit for limited test conditions, this analysis demonstrated that the effects of bias correction were larger when using the data with a larger bias of predicted values from measurement values.