• Title/Summary/Keyword: demand density

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Empirical Analysis of Supplier Induced Demand in Korea: Distinction between Induced Demand Effect and Availability Effect (우리나라 의원에서의 공급자 유인수요 실증분석: 유인수요 효과와 가용성 효과의 구분)

  • Yeo, Ji-Young;Jeong, Hyoung-Sun
    • Health Policy and Management
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    • v.25 no.1
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    • pp.53-62
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    • 2015
  • Background: Supplier induced demand (SID) indicates the case when doctors increase the demand of the patients, following their (physicians') own best interests rather than patients'. This may occur when asymmetry of information exists between suppliers and consumers. This study aims to confirm whether SID exists in the Korean setting, particularly by dividing SID into both 'induced demand effect' and 'availability effect.' Methods: Induced demand effect and availability effect are differentiated following Carlsen & Grytten's theoretical frame which divides doctor density regions into high and low ones. Results: Positive correlation between doctors' density and utilization of their services was found, which could be interpreted as 'availability effect.' Conclusion: The result suggests that additional medical use for additional doctor, particularly in the area of low doctor density, can be interpreted to occur to meet the basic medical need of the people rather than as a result of unnecessary induced demand. It is important to make more medical doctors provided and to distribute them appropriately across the region in such a country like Korea where doctor's density is relatively low.

Daily Gas Demand Forecast Using Functional Principal Component Analysis (함수 주성분 분석을 이용한 일별 도시가스 수요 예측)

  • Choi, Yongok;Park, Haeseong
    • Environmental and Resource Economics Review
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    • v.29 no.4
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    • pp.419-442
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    • 2020
  • The majority of the natural gas demand in South Korea is mainly determined by the heating demand. Accordingly, there is a distinct seasonality in which the gas demand increases in winter and decreases in summer. Moreover, the degree of sensitiveness to temperature on gas demand has changed over time. This study firstly introduces changing temperature response function (TRF) to capture effects of changing seasonality. The temperature effect (TE), estimated by integrating temperature response function with daily temperature density, represents for the amount of gas demand change due to variation of temperature distribution. Also, this study presents an innovative way in forecasting daily temperature density by employing functional principal component analysis based on daily max/min temperature forecasts for the five big cities in Korea. The forecast errors of the temperature density and gas demand are decreased by 50% and 80% respectively if we use the proposed forecasted density rather than the average daily temperature density.

An Empirical Analysis on Public Transportation Demand and TOD Design Factors in Seoul subway adjacent area (서울시 역세권의 TOD환경과 대중교통이용수요 관계분석)

  • Moon, Young-Il;Rho, Jeong-Hyun
    • International Journal of Highway Engineering
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    • v.13 no.4
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    • pp.211-220
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    • 2011
  • TOD(Transit Oriented Development) has recently been active, which presents that TOD planning elements should be comprehensively taken into consideration in order to enhance domestic transit ridership by changing environments in rail station areas and an empirical analysis on the type of rail station areas and transportation demand should be a prerequisite for usage of future development planning. This study aims to grasp a variety of TOD of influence factors in Seoul rail station area and to perform analysis to identify relationship between public transportation demand and these TOD design factors. To make it come true, we gathered data with respect to Density, Diversity, and Accessibility as representative TOD planning elements and carried out factorial and regression analysis. Consequently, we drew 7 influence factors base on factorial analysis: Factor 1(Diversity/ -Use Mix(LUM)), Factor 2(Density/development density), Factor 3(Accessibility/public transportation facility supply), Factor 4(Design/street design), Factor 5(Green/access mode (pedestrian, bike), Factor 6(Design/subway size), Factor 7(Accessibility/Public transit operation) As the result of model development by using factorial and regression analysis, positive influence factors on passenger flow in rail station area are Factor 1(Diversity : Land-Use Mix), Factor 3(Accessibility : public transportation facility supply), Factor 2(Density : development density), Factor 5(Design/ access mode) and Factor 6(subway size) Next, negative influence factor on passenger flow in rail station area shows Factor 7(Accessibility/Public transit operation) as the most influential factor. This is because the growth of service interval of linked subway and bus leads to reduced demand.

A Study on Car Ownership Forecasting Model using Category Analysis at High Density Mixed Use District in Subway Area

  • Kim, Tae-Gyun;Byun, Wan-Hee;Lee, Young-Hoon
    • Land and Housing Review
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    • v.2 no.3
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    • pp.217-226
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    • 2011
  • The Seoul Metropolitan Government is striving to minimize the amount of traffic according to the supply of apartment houses along with the solution of housing shortage for the low income people through high density development near the subway area. Therefore, a stronger policy is necessary to control the traffic of the passenger cars in a subway area for the successful high density development focusing on public transportation, and especially, the estimation of the demand of cars with high reliability is necessary to control the demand of parking such as the limited supply of parking lot. Accordingly, this study developed car ownership forecasting model using Look-up Table among category analyses which are easy to be applied and have high reliability. The estimation method using Look-up-Table is possible to be applied to both measurable and immeasurable types, easy to accumulate data, and features the flexible responding depending on the changes of conditions. This study established Look-up-Table model through the survey of geographical location, the scale of housing, the accessible distance to a subway station and to a bus station, the number of bus routes, and the number of car owned with data regarding 242 blocks in Seoul City as subjects.

Planning of low-rise high-density small-scaled urban housing complex (국내 도시지역에 적용가능한 저층고밀 소형 공동주택 계획안)

  • An, Jae-Min;Mo, Jeong-Hyun
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2009.11a
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    • pp.263-267
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    • 2009
  • Recently, we have seen the change of population and family structure, population growth has slowed and family differentiation was constantly done. A rapidly increase of single and couple household. So small-scaled house demand will be increased. Therefore this study planned to solve recent collective housing problem and to satisfy new housing demand. The purpose of planning was that low-rise high-density small-scaled of urban housing complex. This study used for two methods. First methods were literature analysis for domestic collective houses's present conditions and issues. Other purpose was to confirm change of household. Second method is case studies. It went through two phases to select the cases. The cases selected domestic and foreign each eight, total sixteen. The cases analyzed to twelve elements characteristic of housing complex, unit and community facilities. This study applied one area of Seoul to the low-rise high-density small-scaled housing complex.

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Geochemical Investigations of Contaminated River Waters Part II-Chemical Oxygen Demand of River Water and Industrial Waste Water in Seoul (汚濁河川水의 地球化學的인 硏究 (第 II 報) 서울市內 河川水 및 工場排水의 化學的 酸素要求量)

  • Lee, Yong-Keun
    • Journal of the Korean Chemical Society
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    • v.14 no.1
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    • pp.5-12
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    • 1970
  • River water and industrial waste water in Seoul were studied by means of chemical oxygen demand(COD) as an indicator for water pollution, from August 1967 to July 1968. Rivers flowing through residential and industrial areas are badly contaminated and COD of water in Han River increases as it progresses to downstream. Seasonal variation of COD showed that higher value of COD was observed in spring and lower in autumn. It is clear that the seasonal variation of COD is influenced by the precipitation. Close relationship was found between COD and population density. The lowest COD curve obtained by plotting COD values against population density and show that the curve slopes upward. The discontinuation of the curve was shown at the population density of 14,000/km$^2$; an increase in COD was acute over the population density of 14,000/km$^2$.

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Impact of Current Density, Operating Time and pH of Textile Wastewater Treatment by Electrocoagulation Process

  • Hossain, Md. Milon;Mahmud, Md. Iqbal;Parvez, Md. Shohan;Cho, Haeng Muk
    • Environmental Engineering Research
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    • v.18 no.3
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    • pp.157-161
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    • 2013
  • Treatment of textile wastewater by the electrocoagulation (EC) process is being investigated by this experimental study. The objective of this experiment is to observe the efficiency of the EC process in removing chemical oxygen demand (COD) and turbidity. In this experiment an iron electrode is used in the EC process, and different working parameters such as pH, current density and operating time were studied in an attempt to achieve a higher removal capacity. The results show that the maximum COD removal occurred at neutral pH at operating time 30 min. COD and turbidity removal reaches at maximum, with optimum consumption of electrodes, between current density 85-95 $A/m^2$, and only trace amounts of metals were determined in the EC treated effluent.

Decomposition of the Changes in Wage Density Function : 2000~2007 (임금밀도함수의 변화 및 구성분해 : 2000~2007년)

  • Kim, Dae Il
    • Journal of Labour Economics
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    • v.36 no.3
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    • pp.29-64
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    • 2013
  • This paper documents the recent changes in wage density and decomposes them. Middle group is found to have shrunk, one-third of which reflects the changes in worker composition. The rest mostly reflects insufficient supply response to the rising skill demand within jobs. The pattern is more pronounced among manufacturing, large and unionized firms, and production workers.

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Satellite-based Assessment of Ecosystem Services Considering Social Demand for Reduction of Fine Particulate Matter in Seoul

  • Lim, Chul-Hee
    • Korean Journal of Remote Sensing
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    • v.38 no.4
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    • pp.421-434
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    • 2022
  • Fine particulate matter (PM2.5) has been the biggest environmental problem in Korea since the 2010s. The present study considers the value of urban forests and green infrastructure as an ecosystem service (ES) concept for PM2.5 reduction based on satellite and spatial data, with a focus on Seoul, Korea A method for the spatial ES assessment that considers social demand variables such as population and land price is suggested. First, an ES assessment based on natural environment information confirms that, while the vitality of vegetation is relatively low, the ES is high in the city center and residential areas, where the concentration of PM2.5 is high. Then, the ES assessment considering social demand (i.e., the ESS) confirms the existence of higher PM2.5 values in residential areas with high population density, and in main downtown areas. This is because the ESS of urban green infrastructure is high in areas with high land prices, high population density, and above-average PM2.5 concentrations. Further, when a future green infrastructure improvement scenario that considers the urban forest management plan is applied, the area of very high ESS is increased by 74% when the vegetation greenness of the green infrastructure in the residential area is increased by only 20%. This result suggests that green infrastructure and urban forests in the residential area should be continuously expanded and managed in order to maximize the PM2.5 reduction ES.

Characteristics of Electricity Production by Metallic and Non-metallic Anodes Immersed in Mud Sediment Using Sediment Microbial Fuel Cell

  • Haque, Niamul;Cho, Dae-Chul;Kwon, Sung-Hyun
    • Journal of Environmental Science International
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    • v.23 no.10
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    • pp.1745-1753
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    • 2014
  • Sediment microbial fuel cell (SMFC), equipped with Zn, Al, Cu, Fe or graphite felt (GF) anode and marine sediment, was performed. Graphite felt was used as a common cathode. SMFC was single chambered and did not use any redox mediator. The aim of this work was to find efficient anodic material. Oxidation reduction potential (ORP), cell voltage, current density, power density, pH and chemical oxygen demand (COD) were measured for SMFC's performance.. The order of maximum power density was $913mWm^{-2}$ for Zn, $646mWm^{-2}$ for Fe, $387.8mWm^{-2}$ for Cu, $266mWm^{-2}$ for Al, and $127mWm^{-2}$ for graphite felt (GF). The current density over voltage was found to be strongly correlated with metal electrodes, but the graphite felt electrode, in which relatively weaker electricity was observed because of its bio-oriented mechanism. Metal corrosion reactions and/or a complicated microbial electron transfer mechanism acting around the anodic compartment may facilitate to generate electricity. We presume that more sophisticated selection of anodic material can lead to better performance in SMFC.