• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.679-680
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• 2011

This paper is developed to Energy Balance Flow show the flow of total energy resource be used nationally. The Energy Balance Flow is applicable of demand management factor through the analysis of foreign energy model of supply and demand and energy statistic data in the country. This study is based on and developed to Energy system management model is able to appraisal efficient of energy cost cutting, CO2 emission reduction and Energy saving at the national level calculated effect reached amount of primary energy to change of energy flow followed application of demand side management factor is able to appraisal quantitatively at the total energy to model of demand and supply.

• 한국산학기술학회논문지
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• 제9권3호
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• pp.831-839
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• 2008

전 세계적으로 철강산업의 중요성은 높아지고 있으며, 철강수요 역시 증가하고 있는 추세이다. 한국 철강산업의 철강생산량은 전 세계에서 5위를 차지하고 있어 국내에서는 철강산업에 대한 관심이 커져가고 있다. 또한 철강산업은 국내에서 경제성장을 이끌어 온 국가기간산업중의 하나이다. 이에 본 연구에서는 산업연관분석을 이용하여 철강산업이 국민경제에 미치는 파급효과들을 시계열로 분석하여 보고자 한다. 먼저 수요유도형 모형을 이용하여 생산유발효과, 부가가치 유발효과 그리고 취업유발효과를 살펴 볼 것이며, 아울러 공급유도형 모형 및 레온티에프 가격모형을 적용하여 철강산업의 공급지장효과와 물가파급효과에 대하여 살펴보고자 한다.

• 한국경영과학회지
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• 제31권3호
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• pp.27-40
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• 2006

Today's customer demands in supply chains tend to change quickly, variously even in a short time Interval. The uncertainties of customer demands make it difficult for supply chains to achieve efficient inventory replenishment, resulting in loosing sales opportunity or keeping excessive chain wide inventories. Un this paper, we propose an adaptive vendor managed inventory (VMI) model for a two-echelon supply chain with non-stationary customer demands using the action-reward learning method. The Purpose of this model is to decrease the inventory cost adaptively. The control Parameter, a compensation factor, is designed to adaptively change as customer demand pattern changes. A simulation-based experiment was performed to compare the performance of the adaptive VMI model.

• 한국건설관리학회논문집
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• 제12권5호
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• pp.35-45
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• 2011

최근 한국 주택시장의 혼재하고 있는 문제점으로 인해 공급기반 강화 전략이 중요한 화두가 되고 있다. 특히, 2008년 이후 금융시장 불안으로 인한 주택시장의 침체로 미분양주택 해소 및 서민주거안정을 위한 정책이 요구되고 있다. 그러나 이들은 주택공급조절과 주택공급확대라는 서로 상반된 목표를 갖고 있기 때문에 정책결정에 어려움을 발생시킨다. 따라서 본 연구는 미분양해소 및 서민주거확대를 위한 주택정책 적용 시 주택시장을 구성하는 다양한 변수 간 관계들의 구조적 변화를 파악함으로써 정책 실효성을 분석하는 시스템다이내믹스 모델을 개발한다. 개발된 모텔에 다양한 정책 시나리오를 적용함으로써 가능한 정책대안들을 평가하고, 문제해결을 위한 정책을 제안한다. 연구 결과, 민간을 배제한 공공 주도의 공급정책 및 미분양주택 해결을 위한 민간 주택건설 규제는 건설시장의 자율조절기능을 위축시키는 요소로 작용할 수 있다. 따라서 민간 주택건설의 자율적 조절기능을 지원하는 정책을 마련해야 민간 주택시장의 공급체계 안정화 및 수요-공급 조절기능의 정상화를 이룰 수 있다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2003년도 추계학술대회 및 정기총회
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• pp.334-337
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• 2003

In this paper we presents a centralized model for a long-term replenishment contract model in the supply chain system. We assume ARIMA demand process for reflecting more realistic demand data and present a solution which minimizes total system cost of the contract model between single supplier and buyer under centralized system. From the result of experiments we can observe that the proposed model generate better result than the decentralized model.

• 한국환경복원기술학회지
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• 제23권6호
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• pp.29-41
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• 2020

Wild pollinators provide important pollination services for crops. However, their geographical ranges and impact on pollination services have not been fully explored within the scope of Korean agricultural land. This study aims to identify spatial supply-demand mismatches across orchard fields in the context of assessing pollination service risk. We first used National Ecosystem Survey data and a species distribution model (MaxEnt) to develop the geographic range of each of 32 wild pollinators belonging to three families (Diptera, Hymenoptera, and Lepidoptera). We then summed the modeled presence probability of each species to obtain a measure of spatially explicit pollinator richness. This modeled richness, defined as pollination supply, was compared with the summed area of orchard fields at the municipal boundary level to identify areas with supply-demand mismatches. The study found that Lepidoptera showed the highest species richness (8.3±1.5), followed by Hymenoptera (4.3±0.8) and Diptera (3.5±0.8) species. Median orchard area was 1.5 ㎢ (range of 0-176.7 ㎢) among 250 municipal regions in South Korea. The municipal regions were divided into three categories (tertiles) of low, middle, and high pollination supply and demand according to, respectivley, average polliator richness and orhard area. Finally, we found that 55 municipal regions (accounting for 49% of national orchard land) potentially faced high risk of pollination deficits, 81 regions (48% of national orchard land) faced intermediate risk, and 63 regions faced low risk (3% of national orchard land). In conclusion, this study revealed significant mismatch between pollination supply and demand and developed risk assessment map will guide our future efforts on pollinator habitat conservation and monitoring to conserve crop pollination services.

• 한국시스템다이내믹스연구
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• 제10권1호
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• pp.61-76
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• 2009

We try to use system dynamics to forecast the demand/supply and price, also transportation fare for iron ore. Iron ore is very important mineral resource for industrial production. The structure for this system dynamics shows non-linear pattern and we anticipated the system dynamic method will catch this non-linear reality better than the regression analysis. Our model is calibrated and tested for the past 6 year monthly data (2003-2008) and used for next 6 year monthly data(2008-2013) forecasting. The test results show that our system dynamics approach fits the real data with higher accuracy than the regression one. And we have run the simulations for scenarios made by possible future changes in demand or supply and fare related variables. This simulations imply some meaningful price and fare change patterns.

• Korean Journal of Chemical Engineering
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• 제36권1호
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• pp.12-20
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• 2019

An energy storage system consisting of a battery and a power-to-methanol (PtM) unit was investigated to develop an energy storage system for renewable energy systems. A nonlinear programming model was established to optimize the energy storage system. The optimal installation capacities of the battery and power-to-methanol units were determined to minimize the cost of the energy system. The cost from a renewable energy system was assessed for four configurations, with or without energy storage units, of the battery and the power-to-methanol unit. The proposed model was applied to the modified electricity supply and demand based on published data. The results show that value-adding units, such as PtM, need be included to build a stable renewable energy system. This work will significantly contribute to the advancement of electricity supply and demand management and to the establishment of a nationwide policy for renewable energy storage.

• International Journal of Computer Science & Network Security
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• 제24권4호
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• pp.147-154
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• 2024

The continuous increase in urban population due to migration of mases from rural areas to big cities has set urban water supply under serious stress. Urban water resources face scarcity of available water quantity, which ultimately effects the water supply. It is high time to address this challenging problem by taking appropriate measures for the improvement of water utility services linked with better understanding of demand side management (DSM), which leads to an effective state of water supply governance. We propose a dynamic framework for preventive DSM that results in optimization of water resource management. This paper uses Agent Based Modeling (ABM) with Digital Twin (DT) to model water consumption behavior of a population and consequently forecast water demand. DT creates a digital clone of the system using physical model, sensors, and data analytics to integrate multi-physical quantities. By doing so, the proposed model replicates the physical settings to perform the remote monitoring and controlling jobs on the digital format, whilst offering support in decision making to the relevant authorities.

• 한국경영과학회지
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• 제39권2호
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• pp.97-109
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• 2014

This paper considers a reverse supply chain with simultaneous recovery of used products and manufacturing of brand-new ones. Recovered products are downgraded and have to be sold in a market different from that of brand-new products at a different price. In case of a shortage of recovered product inventory, a brand-new item, if available, can be offered at the price of a recovered product. In other words, one-way demand substitution is allowed. We address the joint decision of when to manufacture brand-new product, when to recover returned product, and how to control demand substitution to maximize the hybrid production system's profits. To this end, we propose a Markov decision Process model and investigate the structure of the optimal policy. Performance comparison is numerically implemented between the models with and without downward demand substitution option under different operating conditions of the system parameters.