• Journal of Korean Society of Transportation
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• v.24 no.7 s.93
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• pp.91-100
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• 2006

Travel Demand Forecasting (TDF) is an essential and critical process in the evaluation of the highway improvement Project. The four-step TDF Process has generally been used to forecast travel demand and analyze the effects of diverted travel demand based on the given Origin-Destination trips in the future. Transportation system improvements, however, generate more travel, Induced Travel Demand (ITD) or latent travel demand, which has not been considered in the project evaluation. The Purpose of this study Is to develop a model which can forecast the ITD applied theory of economics and the Program(I.D.A) which can be widely applied to project evaluation analysis. The Kang-Byun-Book-Ro expansion scenario is used to apply and analyze a real-world situation. The result highlights that as much as 15% of diverted travel demand is generated as ITD. The results of this study are expected to improve reliability of the project evaluation of the highway improvement Project.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4489-4497
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• 2015

This study aims at estimating the consumer's demand and willingness to pay(WTP) for horse meat in Korea. Three econometric models are employed to examine the multiple layers of the demand, including the current demand, the potential demand and latent demand. Findings indicate a substantial demand for horse meat. Dichotomous choice contingent valuation method is used to elicit the WTP. We assess the mean WTP for horse meat using a double-bounded logistic model. As a result, consumers are willing to pay at 67.8 percent of the beef prices of the third quality grade to purchase horse meat. And, for the factors that influence on WTP, only sex, age and recognition of horse meat are statistically significant.

• Safety and Health at Work
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• v.14 no.1
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• pp.85-92
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• 2023

Background: Presenteeism is closely related to work performance, work quality and quantity, and productivity at work. According to the job demand-control-support model, job demand, job control, and support play important roles in presenteeism. The present study investigated job characteristics profiles based on the job demand-control-support model and identify the association between job characteristics profiles and presenteeism. Methods: This secondary data analysis used the Sixth Korean Working Condition Survey, a nationwide cross-sectional dataset. The study included 25,361 Korean wage workers employed in the workplace with two or more workers. Participants were classified into four job characteristics profiles based on the job demand-control-support model, using latent profile analysis, and logistic regression was performed to examine the association between study variables. Results: Overall, 11.0 % of study participants reported experience of presenteeism in the past 12 months. Age, sex, location, monthly income, shift work, work hours, health problems, and sleep disturbances were significantly associated with presenteeism. The rate of presenteeism was the highest in the passive isolate group. The passive collective, active collective, and low-stain collective groups had a 23.0%, 21.0%, and 29.0% lower likelihood of experiencing presenteeism, respectively, than the passive isolate group. Conclusions: The job demand-control-support profiles and the risk of presenteeism were significantly associated. The most significant group that lowered the experience of presenteeism was the low-strain collective group, which had a low level of demand and high levels of control and support. Therefore, we need a policy to reduce job demand and increase job control and support at the organizational and national levels.

• Journal of Biosystems Engineering
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• v.16 no.3
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• pp.290-297
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• 1991

For the efficient utilization of the solar thermal energy to overcome the time gap between to supply and demand, an efficient heat storage technique, especially high density-latent-heat storage system, is necessary. In this study, the performance of a panel type latent heat storage equipment during heat discharging process was analyzed theoretically and experimentally. In order to find out the performance of the system, computer simulation programs were developed by finite difference method. The governing equations were constructed by two dimensional heat conduction model with moving boundary. The results of the experimental and the theoretical analysis were reasonably well agreed. The efficiencies of the double pipe type and the panel type latent heat storage equipment were compared.

• Journal of Korean Society of Transportation
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• v.28 no.3
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• pp.99-107
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• 2010

Analyzing mode choice among transportation demand estimate procedures is complicated and understanding characteristics of travelers is also difficult. Generally, it is well known that traveler choose mode considering psychometric factors and characteristic besides socio-demographic indicators. Accordingly, many researches has investigated on methodology that can be applied in mode choice to reflect psychometric factor or specific preference. Latent Class Analysis among various studies is recognized as the theoretically potential approach. This study focuses on class segmented using latent class cluster to analyze impact that included psychometric factors and characteristics on mode choice. It also provides evidence that mode choice model for each class and mode choice model not considering latent class are different. This study based on citizen's stated preference and revealed preference on a new transit on the Han river shows that latent class cluster analysis is the potential approach considering latent preference.

• Journal of Korean Port Research
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• v.13 no.2
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• pp.323-332
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• 1999

The bus should supply an equal service to the whole community as feeder trip. However the existing bus route can not supply an effective feeder service in spite of the changes in the latent demand by the variety of regional structural change. This study aimed to establish the concept which frames the bus operation and management to cope with the latent demand to the bus. This study tackled this evidence by analyzing the transportation problems in terms of the urban growth emphasizing the following issues ; First, the strategy to improve the bus operation Second the land use control appropriate for the public transportation network Third economical range to justify the bus operation Second, the land use control appropriate for the public transportation network Third, economical range to justify the bus operation Fourth, the allowance for the private transportation mode On the latter part, the difference on the bus operation was compared to determine the range within which the bus operation could be justified. This study would provide some implications to improve the management for bus operation and fundamental information to develop the bus operation system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.123-130
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• 1999

The bus as a feeder trip should supply equality service to the whole community. But in spite of the change of latent demand to the bus by the variety of regional structural change, the existing bus route can not supply effective feeder service. For cope with the latent demand to the bus, this study establish a concept that frame of the bus operation and management. This study tackled to evidence this fact by analyzing the bus transport problems in terms of the urban growth, and following issues were discussed: 1) the strategy for improvement of bus operation, 2) the land use control which is appropriate for the public transport network, 3) the economical range to justify the bus operation, 4) the allowance for the private transport mode. On the second part of this study, the difference on the bus operation was compared to determine the range within which the bus operation can be justified. This would provide the direction to improve the management for bus operation and fundamental information to develop the bus operation system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.316-321
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• 2003

The bus as a feeder trip should supply equality service to the whole community. But in spite of the change of latent demand to the bus by the variety of regional structural change, the existing bus route can not supply effective feeder service. For cope with the latent demand to the bus, this study establish a concept that frame the feeder bus route design system for changing of the existing bus route or creating of bus route. The concept of feeder bus route design system from this study is not to frame the whole bus network but to frame the single route to a unit OD pair. So, this study have assumption that do not consider the wating time at bus stop and transfer time. This system is consist of three phase. First is limitation of examination road network, second is enumeration of a most suitable route, and final is determination of the optimum bus route. However, a precondition is that the necessary time from the origin to the destination is brief, and having many demand.

• Journal of Korean Society of Rural Planning
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• v.26 no.2
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• pp.39-49
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• 2020

This study was attempted to grasp the push-pull factors of urban to rural migrants in relation to services and infrastructure of rural welfare and culture. Online and offline survey were conducted for urban residents who were willing to return to the rural area and those who were already returning to the rural area. In the fields of health care, social welfare, and education, it was found that the satisfaction level of urban-to-rural migrants was relatively higher than those of latent urban-to-rural migrants. In the field of culture, leisure and sports, the level of satisfaction and concern were similar, so it was found that the expectations for the field were relatively high before returning rural area. As for the agreement degree to expand support, the demand for emergency medical facilities and dementia care program was the highest, and the demand for health care was found to be relatively high. The results of the survey on the top priority items indicate that latent urban-to-rural migrants require support of facility and space item and expansion of program item, and urban-to-rural migrants have high demand for expansion of program item in all field except healthcare field. The results of this study are expected to provide useful information for establishing the direction of the rural area development project in connection with the revitalization of policy of people return to rural area.

• Journal of the Korea Society of Computer and Information
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• v.23 no.5
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• pp.9-14
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• 2018

For an efficient management of electricity market and power systems, accurate forecasts for electricity demand are essential. Since there are many factors, either known or unknown, determining the realized loads, it is difficult to forecast the demands with the past time series only. In this paper we perform a cluster analysis on electricity demand data collected from Jan. 2000 to Dec. 2017. Our purpose of clustering on electricity demand data is that each cluster is expected to consist of data whose latent variables are same or similar values. Then, if properly clustered, it is possible to develop an accurate forecasting model for each cluster separately. To validate the feasibility of this approach for building better forecasting models, we clustered data with t-SNE. To apply t-SNE to time series data effectively, we adopt the dynamic time warping as a similarity measure. From the result of experiments, we found that several clusters are well observed and each cluster can be interpreted as a mix of well-known factors such as trends, seasonality and holiday effects and other unknown factors. These findings can motivate the approaches which build forecasting models with respect to each cluster independently.