• 자원ㆍ환경경제연구
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• 제11권1호
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• pp.81-97
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• 2002

Unlike the existing supply-centered water policy, demand management policy of water has become an increasingly important issue in Korea. This paper attempts to analyse the demand for domestic water in Seoul. We employed Engle-Granger's error correction model(ECM) to deduced the price and income elasticities of the water demand. Particularly, we used accounted water amounts instead of supplied water amounts as representative variable of water demand. The result indicates that ECM set up is appropriate and short-run and long-run price elasticities derived by the model are -0.145 and -1.414. In contrast with other studies, we can conclude that the water demand for the water price is elastic. Besides, we can infer from this result that the water price policy with respect to a decrease of leakage ratio is more effective.

• 대한소아치과학회지
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• 제34권1호
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• pp.43-52
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• 2007

현재 우리나라는 치과의사 전문의제도가 도입되고 저출산 고령화 사회로의 급속한 이행 등 여러 이유로 소아치과 전문의 수급에 관한 연구가 절실한 실정이다. 본 연구는 소아치과 전문의 수요추계에 적합한 모형을 모색할 목적으로 의료인력 수급에 관한 타 분야의 기존 연구들을 고찰하여 다음과 같은 결과를 얻었다. 1. 소아치과 전문의의 수요추계는 의료수요에 근거한 방법을 적용하는 것이 적절할 것으로 사료되었다. 2. 추계 모형에 필요한 독립변수로는 크게 유병율, 수진율, 의뢰율 출산율, 생산성, 연간 진료일수 등이 있었으나, 이러한 변수들에 대입하기 위한 기초자료가 부족한 것으로 나타나, 이를 보완할 설문조사와 전문가 의견조사가 필요할 것으로 판단되었다. 3. 독립변수는 각 특성에 적합한 회귀모형을 설정하여 추계하고, 가중치를 주어 추계 모형에 반영해야 할 것으로 판단되었다. 향후 추계 모형에 대입하기 위한 독립변수의 생성과 추계연구, 전문가의 검증과정이 추가로 필요하며 이를 토대로 소아치과 전문의 수요를 추계하여야 할 것으로 사료된다.

• 한국안전학회지
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• 제27권3호
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• pp.49-56
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• 2012

The purpose of this paper is to present a model for operating an emergency power system(EPS) that can secure a sufficient power supply used in case of a fire by analyzing the status of power supplies for emergency and firefighting operations. Investigations on the one of the causes of the operational failure of firefighting systems show evidence of EPS. Generally, when power to a building is interrupted, EPS supplies the emergency load(excepted firefighting load) first. When a power outage and a fire occur simultaneously, the EPS must be able to supply both the emergency load and the firefighting load, especially the firefighting load to the end. However, in order to save construction costs, emergency power generators in apartment, commercial, and business buildings can satisfy only one of the required loads. In cases like this, when a power outage and a fire occur simultaneously, there is a danger of firefighting equipment not operating due to insufficient power supply from the emergency generator. Therefore, an EPS must have a reserved firefighting power that can supply both the firefighting and the emergency load. Such EPS, when faced with a danger of an overload, will shut down the supply to all or part of the emergency load, thus securing a continuous power supply to the firefighting equipment. The generator power system with reserved firefighting power (RFP) will also have an indicator to show that the selective control is being used. General power generation systems for emergency load and firefighting load were found to have a demand factor of 50-60% with a lump. However, when installing an EPS, the builders must choose the higher demand factor suggested according to the official approval demand factor of the building.

• 농업과학연구
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• 제46권4호
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• pp.813-825
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• 2019

This paper investigated the effects of a government production and shipment stabilization policy and the improvement plan for vegetables in Korea. In this study, a simulation focused on the changes in farm income for Chinese cabbages & radishes using scenarios. The result shows an increase in farm income according to the government policy. In the short-term, demand and supply are fixed, and the policy effect is positive due to the price support effect of the project. However, for mid- to long-term, the price decreases due to the expansion of supply by business beneficiaries, which is likely to be adversely affected by an unstable supply and demand. This increases the burden of government and local government subsidies. This phenomenon is expected to be amplified as the ratio of production and shipbuilding stabilization programs and items expand. When expanding items and adjusting and setting the percentage of participation in the project, it is desirable to set and operate the appropriate business ratio taking into consideration the demand. To improve the effectiveness of the policy, the following remedies were suggested. First, national supply and demand guidelines should be set up, and the autonomous supply and demand control of the producers should be guided by the different preservation according to the implementation of the supply and demand control obligation. As for detailed equipment, it is necessary to establish the reproduction price for each item, set the base price for each wholesale market, increase the incentive for the producers to participate, and fund a business budget to secure business stability.

• 한국항해항만학회지
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• 제48권1호
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• pp.7-16
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• 2024

외항 상선 선박 척수가 증가하고 있지만, 한국인 해기사가 감소하여 인력 부족 문제가 심각하게 대두되고 있는 상황에서 본 연구는 외항 상선 해기사 인력 수요와 공급을 결정하는 요인들을 객관적으로 측정하여 정확한 인력 수요와 공급을 예측하고자 하였다. 인력 수요는 선박 규모별 필요 해기사 수의 차이를 반영하여 선박 증가 예측치에 이를 적용하여 직급별로 예측하였다. 인력 공급은 Markov모형을 활용하여 연도별 승진, 이직, 퇴직, 신규 진입 등의 증감요인을 반영하여 직급별 연령별로 세분화하여 예측하였다. 외항 상선 해기사 인력 수요는 2023년 11,638명에서 2030년 13,879명으로 증가하고, 공급은 2023년 7,006명에서 2030년 6,426명으로 감소하여 2040년에는 부족인원이 1만명을 넘는 것으로 예측되었다. 본 연구는 객관적인 데이터와 과학적 분석방법 및 논리적 추론을 통해 예측의 정확도를 제고하여 외항 상선해기사 인력 부족 문제를 해결하는데 유용한 자료로 활용될 수 있을 것이다.

• 수산경영론집
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• 제41권3호
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• pp.59-78
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• 2010

This paper tries to apply the asymmetrical price transmission(APT) behavior observed in the agricultural industry to supply chains of the domestic fishery industry by a statistical manner. The fore mentioned asymmetrical price transmission refers to when price movements in the later stage of the supply chain do not move in a normal or symmetrical manner corresponding to price movements in the earlier stage of the supply chain. Therefore, when the earlier stage price increase and the later stage price increases to a larger degree, it is called positive(+) asymmetry and the opposite behavior is called negative(-) asymmetry. The study examines the data from domestic producers of three fresh fish types, hairtail, mackerel, and cuttlefish, and tries to examine the price asymmetry between the producer or farm, wholesaler, and retail prices via an APT test utilizing unit root, cointegration, and error correction model. The study found, hairtail wholesale and retail pricing bas a negative asymmetric relationship while mackerel has a negative asymmetric pricing relationship at the producer and retail levels of the supply chain. In the case of cuttlefish, all levels of the supply chain showed negative asymmetrical behavior in the supply chain price transmission, meaning the earlier stage price changes are more rapidly and greatly inputted in the later stage of the supply chain pricing. We believe that the reason why the analysis results show negative price asymmetry is due to the uniqueness of fishery products having an important variable such as freshness. If price increases are greater and quicker than price decreases, then consumer demand, which is sensitive to price increases will decrease and subsequently result in the increase of inventory levels, reducing profits for retailers. Also, frozen hairtail, mackerel, and cuttlefish will act as substitute goods to fresh fishery products. Therefore, fresh fishery products have a high demand of price elasticity. When prices increase, demand quickly decreases. Therefore the profit of wholesalers and retailers to decrease, I think this is the main reason of APT in the supply chain of Korea' s fisheries industry.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.495-498
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• 2003

In order to analyze water supply capacity in estuary barrage dam, a system was developed in which base model was consisted of daily water balance model and daily inflow model. Agricultural water demand to paddy fields and domestic and industrial water demand were considered in this daily water balance model. Also outflow volume through sluice gate and inside water level at time to start outflow was conditioned initially to simulate reservoir storage. The DAWAST model was selected to simulate daily reservoir inflow in which return flows from agricultural, domestic and industrial water were included to simulate runoff. Using this developed system, water supply capacity in the Keum river estuary reservoir was analyzed.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.185-185
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• 2023

Agricultural water demand is considered as the major sector of water withdrawal due to irrigation. The majority part of the global agricultural field depends on various irrigation techniques. Therefore, a timely and sufficient supply of water is the most important requirement for agriculture. Irrigation is implemented in different ways in various land surface models, it can be modeled empirically based on observed irrigation rates or by calculating water supply and demand. Certain models can also calculate the irrigation demand as per the soil water deficit. In these implementations, irrigation is typically applied uniformly over the irrigated land regardless of crop types or irrigation techniques. Whereas, the latest version of Community Land Model (CLM) in the Community Terrestrial Systems Model (CTSM) uses a global distribution map of irrigation with 64 crop functional types (CFTs) to simulate the irrigation water demand. It can estimate irrigation water withdrawal from different sources and the amount or the areas irrigated with different irrigation techniques. Hence, we set up the model for the simulation period of 16 years from 2000 to 2015 to analyze the global irrigation demand at a spatial resolution of 1.9° × 2.5°. The simulated irrigation water demand is evaluated with the available observation data from FAO AQUASTAT database at the country scale. With the evaluated model, this study aims to suggest new sustainable scenarios for the ratios of irrigation water withdrawal, high depending on the withdrawal sources e.g. surface water and groundwater. With such scenarios, the CFT maps are considered as the determining factor for selecting the areas where the crop pattern can be altered for a sustainable irrigation water management depending on the available withdrawal sources. Overall, our study demonstrate that the scenarios for the future sustainable water resources management in terms of irrigation water withdrawal from the both the surface water and groundwater sources may overcome the excessive stress on exploiting the groundwater in major river basins globally.

• 인터넷정보학회논문지
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• 제24권2호
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• pp.47-56
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• 2023

수소 에너지는 높은 에너지 효율로 열과 전기를 생산하면서도 온실가스와 미세먼지 등 유해물질 배출이 없는 친환경 에너지로서, 전 세계적으로 탄소중립으로의 전환을 위한 핵심으로 주목받고 있다. 특히 스마트 수소에너지는 경제적이고 지속 가능하며, 안전한 미래 스마트 수소에너지 서비스로써 수소 에너지의 기반 시설이 디지털로 통합되어 '데이터' 기반으로 안정적으로 운영되는 서비스를 의미한다. 본 논문에서는 데이터 기반 수소 충전소 수요예측 모델 구현을 위해 강원도 내 설치되어 있는 수소 충전소 3곳(춘천, 속초, 평창)을 선정, 수소 충전소의 수요공급 데이터를 확보하였고, 머신러닝 및 딥러닝 알고리즘 7개를 선정하여 총 27종 입력 데이터(기상데이터+수소 충전소 수요량)로 모델을 학습하였고, 평균 제곱근 오차(RMSE)로 모델을 평가하였다. 이를 통해 본 논문에서는 최적의 수소 에너지 수요공급을 위한 머신러닝 기반 수소 충전소 에너지 수요 예측 모델을 제안한다.

• 한국국방경영분석학회지
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• 제31권1호
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• pp.73-92
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• 2005

The SCOR(supply chain operations reference) model which is a management tool, has been developed to describe the business activities associated with all phases of satisfying a customer's demand. The model is able to successfully describe and provide a basis for supply chain improvement. In this paper, we review the SCOR model, the present status of the Korean defense logistics system, and suggest an application of the model for the integrated defense logistics system.