• 제목/요약/키워드: Demand and Supply Curves

검색결과 16건 처리시간 0.021초

농업용 저수지 관개 취약성 특성 곡선 산정 (Evaluation of Irrigation Vulnerability Characteristic Curves in Agricultural Reservoir)

  • 남원호;김태곤;최진용;김한중
    • 한국농공학회논문집
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    • 제54권6호
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    • pp.39-44
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    • 2012
  • Water supply capacity and operational capability in agricultural reservoirs are expressed differently in the limited storage due to seasonal and local variation of precipitation. Since agricultural water supply and demand basically assumes the uncertainty of hydrological phenomena, it is necessary to improve probabilistic approach for potential risk assessment of water supply capacity in reservoir for enhanced operational storage management. Here, it was introduced the irrigation vulnerability characteristic curves to represent the water supply capacity corresponding to probability distribution of the water demand from the paddy field and water supply in agricultural reservoir. Irrigation vulnerability probability was formulated using reliability analysis method based on water supply and demand probability distribution. The lower duration of irrigation vulnerability probability defined as the time period requiring intensive water management, and it will be considered to assessment tools as a risk mitigated water supply planning in decision making with a limited reservoir storage.

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

  • 전재현;김영찬
    • 한국ITS학회 논문지
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    • 제9권3호
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    • pp.30-40
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    • 2010
  • 고속도로 본선 정체의 원인으로 진출램프에서 발생한 대기행렬의 본선 역류가 크게 작용하며, 이에 고속도로 진출램프 대기행렬 발생으로 인한 본선 영향을 적절히 표현하는 연속류 모형과 실제 제어 시 기반이 되는 적용성 연구가 필요하다. 본 연구에서는 고속도로 용량 변화에 따른 공급과 수요 곡선을 탄력적으로 적용하여 진출램프 대기행렬 영향으로 인한 고속도로 본선 교통류를 표현할 수 있는 Supply-Demand 모형의 적용성을 평가하였다. 먼저 Supply-Demand 모형 적용 시 요구되는 입력자료인 구간별 Sending & Receiving function과 진출램프 대기행렬의 본선 영향 등을 고려한 고속도로 본선 용량제약을 처리하는 방안을 제시하였다. 실시간 data를 사용하여 Supply-Demand 모형을 적용하는 일련의 과정을 모형화 한 후, 극심한 상습정체가 발생하는 내부순환로의 홍은진출을 포함하는 구간에 적용, 조정 및 발전시켜 분석하였다. 적용결과, 대기행렬의 본선 영향 범위와 대기행렬 패턴이 실제 교통류와 유사하게 예측되었다. 즉, Supply-Demand 모형이 Sending & Receiving function을 탄력적으로 적용함으로써, 진출램프 대기행렬의 본선 역류 등으로 인한 고속도로 본선의 용량 변화가 적절히 반영되는 것으로 검증되었다.

한국공업화과정(韓國工業化過程)에서의 광물자원(鑛物資源)의 수급구조변화(需給構造變化)와 경제성장(經濟成長)에 있어서의 역할(役割) (The Changing Patterns of Demand-Supply and Role of Mineral Resources in Economic Growth during Industrialization of the Republic of Korea)

  • 윤석규
    • 자원환경지질
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    • 제18권1호
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    • pp.65-92
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    • 1985
  • A total of 12 mineral commodities significant in domestic output, economy and/or strategy of the Republic of Korea are chosen to examine the structural changes in production and demand-supply of these minerals during the last two decades of her industrialization. These include iron and manganese ores as the raw materials for iron and steel making, copper, zinc and tungsten ores among other non-ferrous metallic minerals, limestone (cement), kaolin, talc, pyrophyllite and graphite among other non-metallic minerals, and anthracite coal as the only domestic source of fossil energy. These are reviewed historically in time-series based on the statistical data which are tabulated and graphed in terms of domestic output, export, import, apparent demand-supply, its increasing rate, and self-sufficiency rate of each commodity. The increasing rates of demand-supply (IRDS) of some more important commodities are compared with those of Gross Domestic Production (GDP) and Economic Growth Rate (EGR) to evaluate how the IRDS contributed to the GDP and EGR. The major results revealed are as follows: Among the 12 commodities, the domestic output of 8 commodities appeared to have grown with steady upward trends: they are ores of lead, zinc and tungsten, limestone (cement), kaolin, talc, pyrophyllite and anthracite coal. Two commodities, ores of iron and copper, continued with unchanging or slightly declining trends and varied fluctuations, in spite of their cardinal importance to the heavy industry and strategy of Korea. The remaining two, graphite and manganese ore, have gradualy declined in domestic output in which the former has still enough resource potential but the latter has not and virtually ceased its domestic output. Trade patterns for mineral commodities in the Republic of Korea during the last two decades have changed greatly, being marked by a shift from mineral-exporting to mineral importing, mainly because of increasing consumption of mineral raw materials for industrialization rather than beceuse of decreasing output of domestic mineral commodities in quantity. In terms of trade patterns, the 12 commodities concerned in this study can be classified into the following four groups. The 1st group - ores of lead and tungsten have only been exported without imports. The 2nd group - amorphous graphite, and pyrophyllite have mainly been exported but partly been imported. The 3rd group - kaolin, talc and crystalline graphite have equally been exported and imported, but quantity of imports have rapidly been increased with time. The 4th group - ores of iron, manganese and zinc have shifted from exports to imports during the industrialization, particularly owing to the initiation of iron and steel making by the Pohang Iron and Steel Company in the middle 1970' s and the new establishment of the Onsan Zinc Refinery in the late 1970' s. All of the 12 commodities under considerations were far above 100% in self-sufficiency rate before or in the early 1960' s. Recently, however, most of them have been declined to below 100% except for those of limestone (cement) and pyrophyllite. It is particularly serious to identify that the self-sufficiency rates of the three important metallic minerals, iron, copper and manganese ores in 1982 appeared to be 5.1%, 0.5%, and 0.01%, respectively. The average self-sufficiency rate of the total domestic minerals produced in 1982 was 14.4% (in value) for that year. Mining industry appeared to be extremely high in its intermediate demand rate whereas its intermediate input rate to be quite low indicating that mineral raw materials have been exerted strong forward linkage effects upon the other industries rather than backward linkage effects. In comparing the curves of increasing rates of demand-supply of several major minerals - iron ore, manganese ore, copper ore, limestone (cement), kaolin, and anthracite coal - with those of Gross Domestic Production and Economic Growth Rate drawn on every graph, it is clearly shown that the curves of increasing rates of demand-supply comprise around 6 to 7 periods of cycles which roughly harmonious with those of the curves of GDP and EGR, except for the curve of anthracite coal of which the configuration seems to have resulted from the (artificial) government's mineral policy rather than from economic free market mechanism. The harmonic feature of these curves well suggests that the increasing rates of demand-supply of major minerals have been significantly contributed to the GDP and EGR. In addition, the wider amplitudes of the iron, manganese and copper curves than those of the limestone (cement) and kaolin curves indicate that the contribution of the former, metallic commodities, has been greater than that of the latter, non-metallic commodities.

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실시간 저수위 및 용수공급 취약성 지표를 활용한 농업용 저수지 운영 기준 개발 (Development of Operation Rules in Agricultural Reservoirs using Real-Time Water Level and Irrigation Vulnerability Index)

  • 남원호;최진용
    • 한국농공학회논문집
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    • 제55권6호
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    • pp.77-85
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    • 2013
  • The efficient operation and management strategies of reservoirs in irrigation periods of drought events are an essential element for drought planning and countermeasure. Korea Rural Community Corporation has developed the real-time water level observation system of agricultural reservoirs to efficiently operate reservoirs, however, it is not possible to predict drought conditions, and only provides information of current situation. Hence, it is necessary to evaluate accurate irrigation vulnerability and efficiently reservoir operation rules using current water level. In this paper, the improvement methods of reservoir operation planning were developed with water supply vulnerability characteristic curves comparing to automatic water gauge at agricultural reservoirs. The 11 reservoirs were simulated applying the reservoir operation rules which was determined by irrigation vulnerability characteristic curves criteria and real time water level, and evaluated water supply situation in 2012 year. The analysis of results can be identified probabilistic possibility of water supply failures compared with the existing reservoir operation criteria. These results of efficient reservoir operation rules can be achieved enable irrigation planners to optimally manage available water resources for decision making, and contributed to maintain the water supply according to demand strategy for agricultural reservoirs management.

적정 용수 공급량 산정를 위한 추계학적 저수용량 모델 (Stochastic Reservoir Model for the Estimation of Optimal Water Supply)

  • 장인수;박정규;유일준
    • 한국환경보건학회지
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    • 제21권1호
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    • pp.29-38
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    • 1995
  • The purpose of this study is to improve the present methodology-for the estimation of optimal water supply from an impounding reservoir. The stochastic reservoir storage model presented in this paper is believed to be rational in that. the probability of reservoir depletion (return period) is to be calculated for the various monthly demands and storage capacities. The monthly flows are used to derive the reservoir storage capacity-monthly demand-probability curves at Dalcheon damsite and Hongcheon damsite in Han river basin.

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전력시스템 적정 부하율 산정을 위한 단위당 수요관리비용 추정 방안 연구 (A Study on the Estimations Method of Demand-Side Management Cost Per kW and/or kWh to Find Reasonable Load Factor)

  • 황성욱;김정훈;정영범;윤용범
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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    • pp.26-28
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    • 2007
  • To estimate reasonable load factor of power system both supply side and demand side of views should be considered. In the case of this study the demand side is considered and it is supposed that load curves depends on the load factor. The key point of this study is that the cost of demand-side management program per kW and/or kWh should be calculated.

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단일다목적 저수지의 최적운영 (Optimal Operation of Single Multi-Purpose Reservoir)

  • 이순택;이수식
    • 물과 미래
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    • 제18권4호
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    • pp.347-359
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    • 1985
  • 본 연구는 단일다목적 저수지의 운영정책을 수립함에 있어서, DP를 적용하여 댐의 여러 물리적 제약조건하에서 댐 하류의 용수수요를 최대로 충족시킬 수 있는 월별 저수지 최대 운영정책을 수립하는 알고리즘을 개발하는데 주안점을 두었다. 분석대상인 안동댐의 과거 월평균 유입량으로부터 장래 월유입량을 모의발생시키고, 그 모의 발생된 자료 중에서 ddlqfid 계열 A, B, C를 선정하여, 각 계열별로 낙동강 본류의 용수수요 중에서 안동댐이 30%∼100%까지 충족시킬 수 있도록 8개의 대안을 설정하였다. 그리고 DP 모델을 적용시켜 물 수요량과 운영곡선에 근거한 시스템 운영목적함수를 가장 잘 수행하는 대안을 최적 운영 정책으로 결정하였다.

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도로교통의 유발통행수요 추정에 관한 연구 (Estimation of Induced Highway Travel Demand)

  • 이규진;최기주
    • 대한교통학회지
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    • 제24권7호
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    • pp.91-100
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    • 2006
  • 도로개선사업의 타당성 분석을 위해 장래 수요추정은 필수적이며, 이는 사업 여부를 결정하는데 있어서 핵심적 사안이 되지만 현재 장래 수요추정에 적용되는 4단계 수요예측모형은 장래 고정된 기종점통행량을 이용하여 경로 전환된 통행량에 대해서만 분석할 뿐, 교통시스템의 향상으로 인해 추가로 발생되는 수요(유발통행수요-Induced Highway Travel Demand 또는 잠재수요-Latent Demand)는 충분히 고려되지 않고 있어 정확성에 대한 의심의 여지가 있다. 이에 본 연구는 교통수요가 결정되는 원리와 유사한 경제학 이론을 적용한 유발통행수요 추정모형과 광범위한 분석에 적용할 수 있는 유발통행수요 추정프로그램(I.D.A)을 개발하였다. 본 연구에서 구축된 모형을 통해 서울시 강변북로 일부구간의 도로개선에 따른 유발통행수요를 추정한 결과. 추정된 유발통행수요는 경로전환수요의 15% 정도인 것으로 분석되었다. 본 연구를 통해 유발통행수요가 존재할 것으로 확신되는 사업에 대한 유발통행수요를 계량적으로 추정하여 도로개선의 타당성분석결과에 대한 신뢰성을 보다 향상시킬 수 있을 것으로 기대한다.

통일 한국의 징병제와 모병제 하의 병력규모에 관한 연구 (A study on the military size of conscript or recruit under unified Korea)

  • 조홍용
    • Journal of the Korean Data and Information Science Society
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    • 제28권6호
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    • pp.1521-1538
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    • 2017
  • 통일 한국의 적정 병력규모에 관한 연구는 이전부터 있어 왔다. 그러나 대부분의 연구들은 주관적인 데이터를 사용하여 정성적인 평가 방법을 시용해 왔었다. 또한 통계학적인 방법론을 도입한 두 가지 연구에서는 변수의 선택의 오류와 주관적인 데이터의 사용으로 인하여 적절한 결과를 도출하지 못하고 있다. 따라서 본 연구에서는 세계 주요 군사강국 30여개 국가를 대상으로 국방 관련 국가별 고유의 데이터가 아닌 비율화된 데이터를 사용하였다. 이들 객관화된 데이터에 경제학의 수요와 공급의 논리를 적용하였다. 공급방정식들은 병력 비율과 국방비 비율의 회귀직선식으로 산출하였다. 수요방정식들은 공급방정식과 동일한 좌표계를 사용하는 반비례곡선식으로 산출하였다. 이와 같은 방법으로 향후 약 20 - 30 년 후의 통일 한국에 대한 징병제와 모병제의 각각의 경우에 대하여 적정 병력 규모와 국방비 비율을 추정하였다.

주택 및 사무용 빌딩 내 전기기기의 전력 수요 패턴 분석 (Power demand pattern analysis for electric appliances in residential and commercial building)

  • 노성준;이순정;이상우;김광호
    • 산업기술연구
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    • 제30권A호
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    • pp.9-15
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    • 2010
  • Recently, Smart Grid is a emerging topic in power and communication industry. Smart Grid refers to a evolution of the electricity supply infrastructure that monitors, protects, and intelligently optimize the operation of the interconnected elements including various type of generators, power grid, building/home automation system and end-use consumers. In order to successful implementation of Smart Grid, energy management function will be the key factor that coordinates and optimally controls the various loads according to the operating condition and environments, and the load patterns in residential and commercial building will be required as fundamental element for load management. In this study, we collects many types of energy usage data of electric appliances, analyze their load curves, and make the general load patterns for electrical appliance.

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