• Title/Summary/Keyword: 수요공급 곡선

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Analysis of Applicability in the Public Transportation System considering the Cost-volume Supply Curve of New Transit System Bi-Modal Tram (녹색 신교통 시스템 바이모달트램의 비용-수요 공급곡선을 고려한 도시 대중교통체계 적용 특성 분석)

  • Kim, Hong-Seok;Kim, Ryang-Gyun;Ham, Jae-Hyun;Jeon, Jae-Cheong;Yoon, Hee-Taek
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.2303-2308
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    • 2010
  • We studied the cost-volume supply characteristic of public transportation systems focused on Bi-modal Tram in the main cities to analyze the applicability and status for the new transit system Bi-modal Tram as public transportation system. The operation cost considering the characteristic of vehicle, facilities, operation and average cost for respective public transportation system and the time cost considering the travel and transfer time are defined to the social cost, and the cost-volume supply curve is based on this social cost. The cost-volume supply characteristic between public transportation modes in the city is determined on the basis of cost-volume supply curve. Through the comparison between cost-volume supply characteristic of main transportation systems, it is analyzed about the relation between public transportation systems in the city and the characteristic for proper service provision. The application of Bi-modal Tram in the city is concluded that it is effective to reduce the social cost on the existing public transportation system.

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Estimation of regional Low-flow Indices Applicable to Unmetered Areas Using Machine Learning Technique (머신러닝 기법을 이용한 미계측지역에 적용가능한 지역화 Low-flow indices 산정)

  • Jeung, Se Jin;Kang, Dong Ho;Kim, Byung Sik
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.39-39
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    • 2020
  • Low-flow 하천에서의 최저수위를 나타내는 지표이다. 일반적으로 유황곡선의 갈수량(Q355)를 대표적으로 사용한다. Low-flow는 물 공급 관리 및 계획, 관개용수, 생태계등 다양한 분야에 영향을 미친다. 이러한 Low-flow를 산정하기 위해서는 충분한 기간의 유량자료가 필요하다. 하지만 국토의 70%가 산지지형으로 구성되어 있는 우리나라의 경우 국가하천과 1급하천을 제외한 산지유역은 수위관측소가 부재하거나 결측으로 인해 자료가 충분하지 않아 Low-flow분석에 한계가 있다. 이에 과거에는 미계측지역의 갈수량을 예측하기 위해서 다중회귀분석, ARIMA 모형 등 다양한 기법을 사용하였지만, 최근들어 머신러닝 모형의 수요가 증가하고 있다. 이에 본 연구에서는 새로운 패러다임에 맞는 머신러닝 기법인 DNN기법을 사용하고자 한다. DNN기법은 ANN기법의 단점인 학습과정에서 최적 매개변수값을 찾기 어렵고, 학습시간이 느린 단점을 보완한 방법이다. 따라서 본연구에서는 머신러닝 기법인 DNN기법을 통해 미계측지역에 적용 가능한 지역화 Low-flow indices를 산정하고자 한다. 먼저, Low-flow에 영향을 미치는 인자들을 수집하고 인자들간의 상관분석, 다중공선성 분석을 통해 통계적으로 유의한 변수를 선정하여, 머신러닝 모형에 입력자료를 구축하였다. 또한 기존의 갈수량 예측기법인 다중회귀분석 결과와 비교하여 머신러닝 기법의 효용성을 검토하였다.

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Measuring Spatial Accessibility to the Hospitals for Infants, Children, Adolescents, and Elderly Population Using 2SFCA: A Case Study of Chuncheon-si, Gangwon-do (2SFCA를 활용한 노인과 소아청소년에 대한 병원 접근성 분석: 강원도 춘천시를 사례로)

  • Jung, Nan-Ju;Kang, Jeon-Young
    • Journal of Cadastre & Land InformatiX
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    • v.54 no.1
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    • pp.49-61
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    • 2024
  • South Korea faces a declining population and rural areas vanishing due to urbanization. Infrastructure, especially medical facilities, may not be sustainable for a long-term. This may impact vulnerable groups like children, teens, and the elderly, worsened by an aging population and low birth rates. Gangwon-do, notably Chuncheon-si, suffers from rural depopulation and poor healthcare self-sufficiency. In this paper, using 2SFCA(Two-Step Floating Catchment Area), we analyze healthcare access in Chuncheon-si, identifying gaps and vulnerable areas. LISA analysis helps map medical vulnerability, considering patient demand and supply. The Gini coefficient assesses spatial inequality. We propose distributing healthcare services and personnel based on age and region. The aim is to identify locations for additional hospitals catering to the elders, Infants, Children, and Adolescents,considering spatial accessibility.

Traffic Analysis Model for Exit Ramp Congestion at Urban Freeway (고속도로 진출램프 대기행렬 발생 현상 분석모형 개발)

  • Jeon, Jae-Hyeon;Kim, Young-Chan
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.3
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    • pp.30-40
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    • 2010
  • The freeway congestion is largely generated by a mainline spillover of the exit ramp queue. So it is necessary to study for modeling of the phenomenon and applying the model. In this study, the authors evaluated applicability of the Supply-Demand model, which can express traffic flow for the freeway by applying flexibly supply and demand curves for capacity of the freeway. First the authors proposed methods processing input data required in the Supply-Demand model, such as sending & receiving functions and time-varying capacity constraints for the freeway mainline. After modeling the Supply-Demand application model, the authors applied the model to the site including congested Hongeun exit ramp in Seoul Ring-road, and improved the model by adjusting application techniques and calibrating parameters. The result of the analysis showed that the Supply-Demand model yielded a queuing pattern and queue location similar to them observed in the field data, and applicability of the Supply-Demand model was varified.

The mobility of the triangular hub cities against a cause of workers' transfer(Germany, Poland, Hungary) (노동자 이동의 원인에 대한 삼각 허브 도시의 유동성(독일, 폴란드, 헝가리))

  • Seo, Dae-Sung
    • Journal of Digital Convergence
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    • v.18 no.8
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    • pp.21-27
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    • 2020
  • This paper studies the impact of domestic and foreign economic activity on mobility among regions. The shortage of human resources and demand continues in Eastern Europeans. Especially Ukrainians, have entered the Polish labor market to make up for the scarce areas. As a result, Poland's supply and demand in Ukraine is disproportionate. Minimum wage increases are putting continued pressure on employers. Therefore, the regression equation in the form of job-seeker's economic activity ratio, y= AX2+B,(x=settlers) can be used to grasp the relationship between curves. According to the domestic and foreign workers who migrated, economic activities was rather than increasing the local population, the settlers of nearby large cities is more proportional. Empirical analysis has shown that the human resource hub has increased migration to large cities and industrial. The hub 'A'nation has been created for mobility in 4th wave re-industry, and the same re-industrialization (N2) in other cities has attracted nearby human resources, but not settle. After all, the hub relationship between N1 and N2 is a mobile relationship. Due to wage inequality or a positive wellbeing chasm, workers are not settled plant area but a nearby city, or commuting between borders is easy to go into the hub central city. However, this proved on emerging from the relatively temporary settlers in the AI era.

Study of the Lower Duration Curve Characteristic by Reservoir and Weir Couple-operating System in Geum River Basin (금강수계 댐과 보의 운영에 의한 하류 유황특성 연구)

  • Ahn, Jung-Min;Cha, Kee-Uk;Ryoo, Kyong-Sik;Lyu, Si-Wan
    • Journal of Korea Water Resources Association
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    • v.44 no.4
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    • pp.285-293
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    • 2011
  • This study presents effects of downstream control point by coupled operation of dams and multi function weirs in the Geum River. Geum river basin that study area did authoritativeness high quality data to acquisition possibility. We applied the flow duration curve, flow regime coefficient, impounded flow index analysis to investigate the quantitative changes in natural flow regimes. In sphere that water supply is possible, this study applied believability that satisfy 95% at estimation year. Impounded flow index was calculated 0.292 by dam coupled operation and 0.297 by dam-weir coupled operation. The results indicate that the storage amount is increased by 29.7% as being added. Duration flow of downstream control point was improved because became coupled operation by regulation of dam and weir in the geum river.

Portfolio Analysis on the New Power Generation Sources of the Sixth Basic Plan for Long Term Electricity Demand and Supply (포트폴리오 이론을 활용한 제6차 전력수급기본계획의 신규전원구성 비교 연구)

  • Kim, Juhan;Kim, Jinsoo
    • Environmental and Resource Economics Review
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    • v.23 no.4
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    • pp.583-615
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    • 2014
  • Including the rolling black out in 2011, Korea has suffered from rapid increase of electricity consumption and demand forecasting failure for last five years. In addition, because of the Fukushima disaster, high fuel prices, and introduction of new generation sources such as renewables, the uncertainty on a power supply strategy increases. Consequently, a stable power supply becomes the new agenda and a revisino of strategy for new power generation sources is needed. In the light of this, we appraises the sixth basic plan for long term electricity demand and supply considering the changes of foreign and domestic conditions. We also simulate a strategy for the new power generation sources using a portfolio analysis method. As results, a diversity of power generation sources will increase and the share of renewable power generation will be surged on the assumptions of a cost reduction of renewable power sources and an increase of fuel costs. Particularly, on the range of a risk level(standard deviation) from 0.06 and 0.09, the efficient frontier has the most various power sources. Besides, the existing power plan is not efficient so that an improvement is needed. Lastly, the development of an electricity storage system and energy management system is necessary to make a stable and efficient power supply condition.

Effects of Nitrogen Fertilization on the Yield and Effective Components of Chrysanthemum boreale M. (질소시비가 산국의 수량과 유효성분에 미치는 영향)

  • Lee, Kyung-Dong;Yang, Min-Suk;Lee, Young-Bok;Kim, Pil-Joo
    • Korean Journal of Soil Science and Fertilizer
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    • v.35 no.1
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    • pp.38-46
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    • 2002
  • Chrysanthemum boreale M. (hereafter, C. boreale M.), a perennial flower, has been historically used as a natural medicine in Korea. With increasing concerns for health-improving foods, the demand for C. boreale M. has become higher than ever. Howevr, the amount of wild C. boreale M. collected from mountainous areas is not enough to cover all demands. The cultivation system and fertilization strategy are required to meet increasing demand on C. boreale M. with a good quality. We investigated the effects of nitrogen application on plant growth and effective components of C. boreale M. to suggest optimum rate of nitrogen fertilization. C. boreale M. was cultivated in a pot scale (1/2000a scale), and nitrogen applied with rate of 0(N0), 50(N50), 100(N100), 150(N150), 200(N200), and $250(N250)kg\;ha^{-1}$. Phosphate and potassium were applied at the same level ($P_2O_5-K_2O=80-80kg\;ha^{-1}$) in all treatments. Maximum yield achieved in 246 and $226kg\;ha^{-1}$ N treatment on the whole plant and the flower part, a valuable part as a herbal medicine, respectively. Proline was the most abundant amino acid in the flower of C boreal M. and the contents of amino acids increased with increasing nitrogen application rate in flower. Nitrogen recovery efficiency was high more than 41% in all nitrogen treatments and increased to 61.8% in nitrogen N100 treatment. From the nitrogen content, the high nitrogen uptake, the low residue of mineral N and the reasonably good apparent fertilizer recovery, it can be inferred that C. boreale M. made efficient use of the available nitrogen. In flower, contents of Cumambrin A. which is a sesquiterpene compound and has the effect of blood-pressure reduction, decreased with increasing nitrogen application. However, the amount of Cumambrin A in flower increased as nitrogen rate increased, because of increasing flower yield. Conclusively, nitrogen fertilization could increase yields and enhance quality. The optimum nitrogen application rate might be on the range of $225{\sim}250kg\;ha^{-1}$ in a mountainous soil.