• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.4
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• pp.10-17
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• 2015

Currently, there are increasing demand for researches on the development of car-sharing operating strategy. In order to carry out the research, demand for car-sharing is required. However, since previous researches only adopted performance data or demand derived from several assumptions, spilled demand has been spotted due to lack of available cars. For this reason, we plan to suggest the way to estimate the value including spilled demand which has been spotted previously based on the record of utilization on the website of operating company, actual company providing car-sharing service. In the case of 'LH Happycar Service', difference between estimated demand and record of utilization is about twice the difference between estimated demand and record of inquiry. Especially, it is found that service rate does not go above once it reaches to its maximum rate because it cannot satisfy additional demands. In short, when we evaluate the demand for individual station based on the record of utilization only, it would be possible to underestimate the demand especially for the station at full capacity.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.2
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• pp.80-93
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• 2018

Public transit services are generally analyzed based on the correlation of demand and supply. The computation of supply uses accessibility while demand uses travel demands estimation based on residential population. However, the traditional demand estimation has a limitation in analysing in micro-scale compared to the smartcard data traffic. This study analyzed potential improvement of public transit services using smartcard traffic data. The supply of transportation was defined using time distance accessibility. Also, time loss was calculated in those origin destination(OD) pairs where time distance accessibilities are relatively low. The proposed method was applied at Seoul. The results showed that the areas where OD pairs need improvement include Seodaemun-gu, Guro-gu and Nowon-gu.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.1
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• pp.73-83
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• 2007

Network modeling of irrigation system that links irrigation facilities with stream is necessary to establish complicated rural water management system and to manage agricultural water effectively. This study attempted a network modeling for an agricultural water district called "ANGO" located in Anseongcheon watershed by connecting ArcHydro Model developed to control geographical information data in the field of water resources and AWDS(Agricultural Water Demand & Supply Estimation System) developed by KRC (Korea Rural Community & Agriculture Corporation). Network modeling was embodied by build topology between spatial objects of total 70 agricultural irrigation facilities (24 reservoirs, 18 pumping stations, 28 weirs) and stream network using ArcHydro Model. In addition, new menus were added in ArcGIS system for query and visualization of text-based AWDS outputs such as irrigation facilities information, water demand and supply analysis.

• Journal of Korea Port Economic Association
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• v.37 no.1
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• pp.179-196
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• 2021

Port congestion rate at Busan Port has increased for three years. Port congestion causes container reconditioning, which increases the dockyard labor's work intensity and ship owner's waiting time. If congestion is prolonged, it can cause a drop in port service levels. Therefore, this study proposed an anomaly detection method using ARIMA(Autoregressive Integrated Moving Average) model with the daily volume data from 2013 to 2020. Most of the research that predicts port volume is mainly focusing on long-term forecasting. Furthermore, studies suggesting methods to utilize demand forecasting in terms of port operations are hard to find. Therefore, this study proposes a way to use daily demand forecasting for port anomaly detection to solve the congestion problem at Busan port.

• Journal of Energy Engineering
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• v.25 no.2
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• pp.37-44
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• 2016

The demand for electricity has a considerable impact on various energy sectors since electricity is generated from various energy sources. This paper attempts to estimate the electricity demand function and obtain some quantitative information on price and income elasticities of the demand. To this end, we apply a lagged dependent variable model to derive long-run as well as short-run elasticities using the time-series data over the period 1991-2014. Our dependent variable is annual electricity demand. The independent variables include constant term, real price of electricity, and real gross domestic product. The results show that the short-run price and income elasticities of the electricity demand are estimated to be -0.142 and 0.866, respectively. They are statistically significant at the 5% level. That is, the electricity demand is in-elastic with respect to price and income changes in the short-run. The long-run price and income elasticities of the electricity demand are calculated to be -0.210 and 1.287, respectively, which are also statistically meaningful at the 5% level. The electricity demand is still in-elastic with regard to price change in the long-run. However, the electricity demand is elastic regarding income change in the long-run. Therefore, this indicates that the effect of demand-side management policy through price-control is restrictive in both the short- and long-run. The growth in electricity demand following income growth is expected to be more remarkable in the long-run than in the short-run.

• Journal of Korean Society of Transportation
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• v.29 no.2
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• pp.81-89
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• 2011

Trip distribution is the second step of the conventional travel demand estimation process, which connects trips between origin and destination, while transport mode choice is the third step of the process, which chooses transport mode among several modes serving for each origin-destination pair. Although these two steps have closely connected, they have been estimated independently each other in the estimation procedure. This paper presents an integrated model combining trip distribution and transport mode choice, and also presents its solution algorithm. The model integrates gravity model adopted for the trip distribution process with logit model employed for the mode choice process. The model would be expected to cope with the inconsistency issue existing in the conventional travel demand estimation procedure. This paper also presents an equilibrium condition, sensitivity of the model, and compares them with those of existing models.

• Journal of the Society of Disaster Information
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• v.13 no.2
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• pp.199-212
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• 2017

Rapid roadway snow removal is significantly important due to difficult occurrence estimation of heavy snowfall disasters by global warming and climate change. Local governments of S. Korea have snow removal equipments and vehicles based on past experiences without considering snowfall and roadway characteristics. The objective of this research is to develop the demand estimation procedure for snow removal equipments and vehicles based on regional snowfall and roadway characteristics. This research first classifies regional snowfall characteristics using KMO's ten-year snowfall data. Second, roadway snow removal length is computed for local governments. Real possession data is compared with demand estimation of snow removal equipments & vehicles for each local government with roadway snow removal scenarios. Finally, required demands of snow removal equipments & vehicles are predicted by concerning regional snowfall amount and required snow removal hours. Results from this research are used for developing heavy snowfall disaster management policies for optimal demands and snow removal routes of 229 local governments.

• Journal of Korea Trade
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• v.25 no.4
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• pp.146-163
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• 2021

Purpose - This paper examines China's impact on Korea's ICT exports considering the direct competition channel, the production shift channel, and the indirect demand channel at once. This paper also takes China's economic rebalancing into account and discusses whether it makes any differences in the effect of the three channels. Design/methodology - To quantify the effect of the three channels, I constructed a linear panel regression model and estimated it with various estimation methods including the system GMM. China's exports toward the same destination as Korea's exports, Korea's exports toward China, and the third countries' exports toward China respectively reflect the three channels. China's GVC indicators are included as well to evaluate the effect of further China's economic rebalancing. Since the present paper has a greater interest in the effect of China rather than the determinant of bilateral trade, a (fixed effect) panel model becomes more appropriate than the gravity model because timeinvariant variables in the gravity model, such as the distance and the language, are eliminated during the estimation process. Findings - The estimation results indicate that Chinese ICT exports are complementary to Korea's ICT exports in general. However, when markets are considered in subgroups, China's ICT exports could have a negative effect in the long run, especially for SITC75 and SITC76 markets, implying a possible competitive threat of China. The production shift effect turns significant during China's economic rebalancing in the markets for the advanced economies and the SITC76 product. China's indirect demand channel is also in effect significantly for the advanced economy and SITC75 commodities during China's economic rebalancing periods. In addition, this paper shows that China's transition toward upstream in the global value chain could have a positive impact on Korea's ICT exports, especially at the Asian market. Originality/value - The contribution of this paper is threefold. First, it focuses on the ICT industry for which Korea increasingly depends on China and China becomes a global hub of the GVC. Second, this paper quantitatively studies three channels in a model in contrast to the literature which mostly examines those channels separately and pays less attention to the GVC aspect. Third, by utilizing relatively recent data from the period of 2001-2017, this paper discusses whether China's economic rebalancing affects the three channels.

• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.51-63
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• 2008

Jeju-Mainland demand for air passenger is variated by the season because most of the demands stem from the leisure travel. This research is to estimate the econometrics demand models(A simple time series model and the partial adjustment model) and elasticities of each models for the Jeju-Mainland domestic routes air travel market using the time series aggregate data between the year 1996 and 2005. As the result of estimating, income elasticity was evaluated to be elastic(1.55) and fare elasticity was inelastic(-0.49${\sim}$-0.59) for A simple time series models. In the partial adjustment model's case, income elasticity was evaluated to be inelastic(0.51) in short-run whereas it was evaluated to be elastic(1.88) in long-run. Fare elasticity was evaluated to be inelastic in short-run(high-demand season: -0.13, slack season: -0.20) and long-run(high-demand season: -0.48, slack season: -0.72).

• Health Policy and Management
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• v.33 no.4
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• pp.457-478
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• 2023

Background: This study aims to contribute to the adjustment of the appropriate doctor manpower by analyzing the distribution, supply and demand, and estimation of the doctor manpower. Methods: This study utilized the medical personnel data of the Ministry of Health and Welfare, population trend data of the National Statistical Office, and health insurance benefit performance data of the National Health Insurance Service. Based on 2021, we compared the number of doctors in actual supply and the number of doctors in demand according to the amount of medical use by gender and age for 250 regions. Logistic regression analysis and scenario analysis were performed to estimate the future medical workforce by considering the demand for doctors according to the future demographic structure, the size of the quota in medical schools, and the retirement rate. Results: There were 186 regions in which the supply of doctors was below average, and the average ratio of the number of doctors in supply to demand in the region was 62.1%. Conclusion: In order to increase the number of active doctors nationwide to at least 80%, 7,756 people must be allocated. The number of doctors in demand is estimated to decrease after increasing to 1.492 times in 2059. The future projected number of doctors is expected to increase to 1.349 times in 2050 and then decrease taking into account the doctor quota and the retirement rate.