• Proceedings of the KOR-KST Conference
• /
• 1998.10b
• /
• pp.466-466
• /
• 1998

도로 교통의 혼잡이 나날이 증가되고 있는 현실 상황에서 이를 해결하기 위한 새로운 도로의 무제한적 건설은 정보의 예산절약, 필요한 도로용지 확보의 어려움, 환경오염 문제 등으로 인해 현실적인 한계에 이르렀다. 따라서, 이러한 도로의 혼잡상황에 효과적으로 대처하기 위해서는 승용차를 이용하고자 하는 수요를 대량수송이 가능한 대중교통 이용수요로 전환시켜야 하며, 이를 위해서는 대중교통의 서비스수준 제고 및 운영 관리 체계 등의 개선이 필요하다. 이를 위한 전략적 및 운영적 측면에서의 대중교통계획은 미래 대중교통수요의 정확한 예측을 전제로 하여 수립되며, 이러한 수요의 예측은 필수적으로 현실을 보다 더 정확하게 묘사해 줄 수 있는 통행배정모형을 필요로 한다. 대중교통 통행배정은 규칙적인 배차시간과 정해진 노선을 운행하는 고정서비스 시스템으로 구성되어 있어서 한 링크 상에서도 여러 개의 운행노선을 고려해야 하기 때문에 승용차 통행배정과는 독립적으로 취급되어 왔으며, 이로 인해 그 동안 많은 연구가 선행되어 있지 않은 실정이다. 본 연구는 교통예측 프로그램 중의 하나인 EMME/2에서 사용하고 있는 대중교통수요 통행배정 모형인 최적전략모형(Optimal Strategy Model)의 단점을 보완하기 위한 것이다. 최적전략모형은 수요 배정시, 최적전략에 속하는 경로들에 대해 단순히 운행횟수에 비례하여 수요를 배정함으로 인해서, 예를 들면 운행횟수는 많지만 환승이 많은 경로에 수요를 많이 배정하는 것과 같은 비현실적인 결과가 발생하기도 한다. 본 연구는 이를 개선하기 위해서, 두 가지 대안을 제시했다. 먼저, 노선배정에 우선되는 최적경로 탐색시 환승노드에서의 환승에 대한 벌점을 그 노선의 운행회수에 줌으로써 환승이 많은 경로에 수요의 배정이 적게 되도록 하는 방법과 두 번째로 수요의 배정시 운행횟수가 아닌 목적지까지의 통행시간과 대시시간에 따른 확률적 배분을 통해 기존 모형의 단점을 보완하고자 했다.

• Journal of the Korean Data and Information Science Society
• /
• v.22 no.2
• /
• pp.137-148
• /
• 2011

In this paper, we systematically investigate regional differences of the dead due to injuries in cities, towns and counties about transportation accidents, suicides and fall accidents, which have recently been an important issue of health problems in Korea, The data are from the Annual Report on the Cause of Death Statistics in Korea in 2008. They include the deaths over the age 19 from transportation accidents, suicides and fall accidents with the criterion of the International Statistical Classification of Diseases. Poisson HGLM is applied to estimate the mortality rate under the assumption that the number of deaths follow a Poisson distribution, by considering regions as random effects and by adjusting age, sex and standardized residence tax as fixed effects. Using the results of random effects prediction, the regional differences in cities, counties and towns are marked in disease mapping. The results showed that there were significant regional differences of mortality rates for transportation accidents and suicides, but no significant differences for fall accidents.

• Korean Journal of Cognitive Science
• /
• v.32 no.1
• /
• pp.1-53
• /
• 2021

The aim of this study was to analyze word frequency effects on eye fixation duration in Korean reading with a one-boundary diffusion model and to show how these phenomena differ between adults (20-28yrs) and adolescents (13-14yrs). We predicted that the drift rate parameter in the boundary diffusion model would reflect the information processing of the fovea during silent reading. Through an eye movement tracking experiment while controlling word properties such as the word frequency and the age of acquisition, Experiment 1 and Experiment 2 show that the information processing pertaining to words to be placed in the fovea is connected to the drift rate of the one-boundary diffusion model parameters. In Experiment 1,in the adult group, the mean difference in the fixation time in the response proportion between the presence of high-frequency condition and low-frequency condition in the adult group was higher in quantile 0.9 than it was in the 0.1 quantile, but in the adolescent group, the mean difference in the fixation time in the response proportion between the two conditions was not significantly in the 0.9 quartile.In Experiment 2, the mean difference in the fixation time in the response proportion between early-acquired condition and late-acquired condition in both groups was also higher in the quantile 0.9 than in the 0.1 quantile. The distribution of the two conditions in the both groups was positively skewed, and the difference showed the same pattern found in the results of Ratcliff(Ratcliff & McKoon, 2008). Based on the experimental results, we propose one-boundary diffusion model as a tool to explain word property effects and individual differences in reading. In particular, we suggest that the drift rate parameter in the boundary diffusion model reflects the information processing of the fovea during reading. In addition, the results show that one-boundary diffusion model can be used to predict the aforementioned phenomena in reading.

• Journal of Animal Science and Technology
• /
• v.49 no.2
• /
• pp.177-182
• /
• 2007

The objective of this study was to evaluate the genetic relationship between weaning weight (WW) and carcass traits. Carcass traits were eye muscle area(EMA), back fat thickness(BFT), marbling score 1(MS1) in 21 grade scales, marbling score 2(MS2) in 7 grade scales and meat color scores(Mcolor). Parameters were estimated by REML procedure with MTDFREML package. Models included contemporary group as defined by the same year-season-sex at birth, linear covariates of age(days) at weaning, age of dam(days) and age at slaughter(days) as fixed effects and animal random effects for all the traits. Heritability estimates of WW, EMA, BFT, MS1, MS2 and Mcolor were 0.25, 0.20, 0.20, 0.32, 0.32 and 0.22, respectively. Genetic(phenotypic) correlation coefficients of WW with EMA, BFT, MS1, MS2 and Mcolor were 0.75(0.16), 0.18(0.05), －0.41(－0.09), －0.40(0.11) and －0.07(0.05), respectively. Results from this study suggest that single trait selection for weaning weight would lead to progeny population having carcass with large EMA, thick BFT and decreased MS.

• Journal of Animal Science and Technology
• /
• v.49 no.2
• /
• pp.183-194
• /
• 2007

We examined the expression patterns of the chicken TCs(tentative consensus sequences) originated from GermOnline genes in various chicken tissues, applying information from GermOnline to chicken organisms. 42 TCs among 84 chicken homologous TCs from the pool of 84 genes related to germ cell lineage in mouse(10), rat(71) and human(3) had high homology based on a BLAST search. Of these, Hmgcs2 and Sycp3 was shown to be expressed in a testis- specific manner and a reproductive organ(testis and ovary)-specific manner, respectively, by RT- PCR analysis. Crmp4, Cyct, Ldhc, Epha7, Pcsk4 and Dnmt3a are expressed in brain, testis, and ovary. The characterization of chicken genes originated from GermOnline in this research may give an enormously useful source of information related to germ cell development.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.3 no.2
• /
• pp.87-95
• /
• 1983

Trihalomethane removal efficiency by a fixed bed carbon adsorber was a subject of this study. Along with laboratory scale column operations, a simple adsorption model was developed to predict removal efficiency. The adsorption model includes an overall mass transfer coefficient, K and Freundlich adsorption constants, $K_F$ and n. Simulation results showed that increasing K and $K_F$ or decreasing n would take more loading and prolong run time of the adsorption bed. Typical S-shaped breakthrough curves were obtained from the experiments. The operational results at $20^{\circ}C$ and $25^{\circ}C$ indicated that a moderate difference in water temperature would not affect the treatment efficiency significantly. The adsorption constants determined from the column operation and the model simulation were reasonably close to those obtained from the isotherm test. It may be concluded that trihalomethane can be removed successfully by a fixed bed carbon adsorber.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.10 no.6
• /
• pp.137-143
• /
• 2010

A method for improving prediction accuracy through processing time series data has been studied in this research. We have designed techniques to model multiple similar time series data and avoided the shortcomings of single prediction model. We predicted the future changes by effective rules derived from these models. The methods for testing prediction accuracy consists of three types: fixed interval, sliding, and cumulative method. Among the three, cumulative method produced the highest accuracy.

• Korea journal of population studies
• /
• v.28 no.1
• /
• pp.47-71
• /
• 2005

본 연구는 사망원인통계의 질과 밀접한 관련이 있는 사망진단서 첨부율이 지역간 큰 격차를 보인다는 사실에 기초하여 어떤 요인이 이 현상에 영향을 미치는지 파악하는 데 목적이 있다. 이를 위해 1991년부터 2000년까지 10개 년 간 6개 대도시 및 9개 시도의 지역별 사망진단서 첨부율과 각 지역의 사망자, 신고자 및 기타 지역 특성을 사망신고자료와 지역통계연보를 통하여 수집하였다. 이 패널자료를 분석함에 있어서 진단서 첨부율에 영향을 미치되 불가피하게 누락된 요인의 영향은 가변수를 사용하는 고정효과모형을 이용하여 보정하였다. 분석에 포함된 변수 중에서는 사망자의 교육수준과 병원사망자 비율이 사망진단서 첨부율의 지역별 차이를 낳는 주요 요인인 것으로 나타났다. 따라서 사망원인통계의 추가적인 질 제고를 위해서는 국가정책수립에 있어서 사망원인통계의 중요성에 대한 홍보 및 교육과 농어촌 벽지 및 도서 지역 등 의료이용이 여전히 어려운 지역에서의 의료기관 이용률 제고를 위한 노력을 기울여야 할 것이다.

• Journal of Labour Economics
• /
• v.32 no.3
• /
• pp.1-26
• /
• 2009

Using panel data from the Korean Labor and Income Panel Study(KLlPS), we examine the wage differentials between standard and Don-standard workers. To control for unobserved individual heterogeneities, we estimate the fixed effect models. Our results show that the OLS estimates are upwardly biased. We also find that labor unions and firm size are important determinants of the wage differentials.

• Environmental and Resource Economics Review
• /
• v.24 no.1
• /
• pp.225-249
• /
• 2015

There are growing interests in the introduction of consumer's selective electricity tariff systems in order to enhance demand response in electricity market in Korea. Real time pricing (RTP) and Time of Use (TOU) are typical examples of demand response system through which electricity price is linked to real time demand. This paper adopts an agent-based model to analyze the effects of such demand system on the counsumers' electricity costs. The result shows that real time pricing system is effective to reduce electricity costs of consumers by providing more flexible tariff system, depending on each consumer's demand pattern. This finding could be used as a basis for supporting smart grid system in the presence of responsive demand environment.