• 한국농공학회:학술대회논문집
• /
• 한국농공학회 2005년도 학술발표논문집
• /
• pp.61-67
• /
• 2005

Agricultural water for rice growing is the important factor of water resources in Korea. so, it is imperative to know the practice of water management in paddy field. The experimental site has been operated in order to investigate water management practice and water supply discharge since 2001. There are 8 irrigation areas which are observed the water supply discharge in this site. We have investigate the water management practice in this site and we know that the practical date of rice growing stages and the date for calculating the water demand in paddy field. So, There is much differences between the calculated water demand and practical water supply. We could reduce the differences by calculating the water demand using the practical date of rice growing stages.

• 전기학회논문지
• /
• 제67권1호
• /
• pp.16-21
• /
• 2018

As a result of the Fukushima disaster and climate change due to excessive greenhouse gases, international energy affairs are currently focused on establishing safe and environment-friendly policies. To achieve this, Republic of Korea has established a plan for environment-friendly energy supplies. It is expected that policy enforcement will be accompanied by an increase in energy supply costs. An analysis of energy supply costs is necessary before the establishment of any national energy policy. This paper analyzes and compares the energy supply costs accompanying environmental and nuclear energy policies, based on the Korean National Energy Master Plan and the Basic Plan for Long-Term Electricity Supply and Demand, in order to understand the implications of these national energy policies.

• 한국시스템다이내믹스연구
• /
• 제12권4호
• /
• pp.157-175
• /
• 2011

The purpose of this paper is to find out the effects of the gambler's fallacy bias on the supply chain. For this study, the simulation was based on a casual structure of the Beer Distribution Game from Sterman(2000)'s Business Dynamics and designed into 2 different models : the first model carries the exact same structure as the reference mentioned above and for the second model, the comparison model is used reflecting gambler's fallacy bias. Each model has 2 different demand patterns. The 4 cases of models was tested with 1,000 different random number seeds. The results for the simulation are following : In the aspect of the inventory and out of stock, the basic model resulted better than the comparison. However, in the bullwhip effect, the comparison model has less than the basic in terms of the level demand pattern. But there was no significant difference in the cycle demand.

• 한국산림과학회지
• /
• 제83권2호
• /
• pp.133-147
• /
• 1994

폐지의 재활용은 부족한 제지원료의 조달 뿐 아니라, 많은 환경문제를 야기하고 있는 쓰레기의 감량, 에너지 절약 및 임목자원 절약 등과 관련하여도 중요한 의미를 갖고 있다. 이 연구는 (1)국내폐지의 수요 및 공급함수를 추정하고 (2)이들 모델을 이용하여 폐지의 수급을 예측하였으며 (3)모델에 포함된 변수들의 수요(需要) 공급탄력성(供給彈力性)을 추정함으로써 폐지의 재활용을 촉진시킬 수 있는 정책수립의 기초자료제공을 위하여 수행되었다. 이 연구에서는 폐지를 폐신문지, 폐골판지 및 기타 잡폐지의 3가지로 구분하여 각각의 수요 공급함수를 추정하였는 바, 수요함수는 종이 종이제품의 생산량 및 도매물가지수의 함수로 추정되었으며, 공급함수는 폐지의 가격, 전년도 종이 종이제품의 수요량 및 운송비의 함수로 추정되었다. 폐지의 총수요량은 1990년 3,342천톤에서 2000년에는 11,645천톤으로 약 3.5배 증가할 것으로 예측되었으며, 공급량은 1990년 총 1,875천톤에서 2000년에 약 7,396천톤으로 추정되었다. 총 폐지의 자급율은 2000년에 평균 약 63.5%에 이를 것으로 예측되었으나 폐신문지의 자급율은 16%로 추정되어 2000년에는 약 2,205천톤의 폐신문지를 외국에서 수입하여야 할 것으로 예측되었다. 끝으로 현재 폐지재활용에 관한 문제점을 제시하고 폐지가 갖고 있는 경제적 물리적 특성 및 구명된 폐지시장의 수급구조를 바탕으로 재활용을 촉진할 수 있는 몇가지 방안을 제시하였다.

• 한국인구학
• /
• 제8권1호
• /
• pp.47-65
• /
• 1985

Three stages of population growth during last forty years affected differently to the labor force and employment in Korea. The first impact of rapid population growth on the labor force occured after the end of World War II. Sudden growth of population due to repartriation and refugees directly increased the labor force. Deteriorating labor market conditions were caused not only by the explosive labor supply but also by the shortage of employment opportunities due to a lack of productive facilities. This severe excess supply of labor continued until the early 196Os. Population growth in the second stage which caused by high fertility during the post Korean War baby boom period induced an eventual increase in the labor supply with time lag of more than fifteen years. Younger persons born during baby boom period were flooded the labor market. Fortunately, job opportunities were expanded more rapidly than the labor force supply because high rates of economic growth and speedy industrialization were continued until the later half of 1970s. Unemployment, therefore, decreased dramatically during this period. The effect of third stage which is characterized as mitigated population growth due to birth control has appeared in the labor market since late 1970s. The growth rate of labor force has been going down and the proportion of younger workers was also been decreasing. From the early 1980s, furthermore, partial disharmony between supply of and demand for the younger workers is closing up. Less educated younger workers who works at low wage are lacking while more educated youngers who want to work at high wage are being excess, because a lot of younger prefer higher education rather than productive job. It is expected that the structural inharmony will be diversified in the future in Korea. The labor force will be changed to middleaged, highly educated and womenized till year 2000, and, after then, to old-aged. On the demand side, industries and jobs will transferred to be labor-saving and soft. These structural changes of labor supply and demand will not matching in time. Aggregate supply of labor force will be steadily increasing more rapidly than aggregate demand for labor until year 2000, and this trend will continue to the first one or two decades of the 2lth century because the persons born dufing the baby boom pariod are being eligible couples in recent. Therefore, conclusion is that appropriate manpower development policy as well as sustained birth control policy is necessary for harmonizing the structural unbalance and the disequilibrium between aggregate labor supply and demand in the future.

• 한국축산식품학회지
• /
• 제42권5호
• /
• pp.762-774
• /
• 2022

The COVID 19 pandemic resulted in a considerable influence on the world economy. Being a big sector of the economy, the food supply chain struggled. The meat supply chain was most notably affected as every part of the supply chain from farm to shelf was closely inter-related. With the closure of businesses and restaurants the demand for at home food from grocery stores increased. Meat production facilities were impacted when the virus spread to the workers causing facilities to close or line speeds to slow. The combination of these two issues, in turn, led to there being less meat on the shelves. With less meat animals being harvested, there was less demand for livestock leading to farmers having an excess in slaughter ready animals. The decreased demand for livestock led to economic issues as money was lost in multiple sections of the supply chain. Aside from the economy and supply chain issues, other issues include concerns over the safety of meat products due to decreased safety protocols to increase line speed. Additionally, concerns of animal welfare with the excess of animals being culled were raised due to decreased capacity in processing facilities. While this review paper mainly focuses on characterizing the impact of COVID 19 on the meat supply chain in the USA, the compiled information should be able to provide practical insights to the meat/food industry across the globe to develop potential mitigating strategies against the COVID 19 and/or any similar pandemic incidences in the future.

• 한국시뮬레이션학회논문지
• /
• 제15권3호
• /
• pp.39-47
• /
• 2006

대부분의 공급망 계획에서 사용되는 각 계획 기간 내의 예측수요는 확정적인 것으로 간주한다. 그러나 현실에서 주어진 계획 기간 내의 수요 예측값은 확률적으로 분포를 따르는 것이 일반적이다. 본 연구는 기존의 안전재고를 통한 서비스 수준을 관리하는 방법을 대신하여 고객 수요의 분포내의 특정한 값을 수요 예측값으로 사용하는 수요선택 방법에 대해 다룬다. 수요 분위수와 계층 재고의 개념을 활용하여 서비스 수준 제약이 존재하는 시리얼 재고시스템을 대상으로 비교적 간단하지만 효과적인 수요선택을 위한 휴리스틱 알고리듬을 제안한다. 시뮬레이션을 활용한 비교 실험을 통해 제안된 알고리듬이 최적해와 유사한 매우 정확한 결과를 보임을 입증하였다.

• 한국경영과학회지
• /
• 제31권1호
• /
• pp.73-82
• /
• 2006

Supply chain management (SCM) has been regarded as one of the most critical issues in the current business environment. Moreover, supply chain partnerships between suppliers and buyers in SCM have had a significant impact on supply chain performance. In this paper, we conduct a quantitative analysis for supplier-buyer's profit sharing and pricing policies based on supply chain partnerships. For this purpose, we assume that a two echelon supply chain with a single supplier and a single buyer is given and the buyer faces deterministic demand which is not only a function of buyer's selling price, but also strictly decreasing, concave, and twice differentiable function. Then we will prove the following. Firstly, without supply chain partnerships, there exist supplier and buyer's selling prices per unit such that their total profits are maximized, under the assumption that buyer's order quantity is exactly equal to the demand buyer faced. Secondly, buyer's selling price per unit which maximizes supply chain's total profit with supply chain partnerships is lower than buyer's selling price per unit which maximizes buyer's total profit without supply chain partnerships. Thirdly, given supplier's selling price per unit. buyer's total profit without supply chain part nerships is greater than that with supply chain partnerships, whereas the opposite case happens for supplier's total profit. Finally, there exists supplier's selling price per unit which makes the maximum total profits for both supplier and buyer with supply chain partnerships greater than those obtained for any given supplier's selling price per unit without supply chain partnerships.

• 한국인터넷방송통신학회논문지
• /
• 제20권6호
• /
• pp.151-156
• /
• 2020

최근 복지서비스의 확대에 힘입어 여러 정부기관에서 복지 관련 서비스를 다양하게 제공하고 있으며 이에 따라 복지관련 서비스의 양과 질의 향상이 동시에 이루어지고 있다. 복지서비스 향상과 더불어 부적정 신청자로 인한 부정·중복수급율도 증가하고 있다. 특히 여러 기관에서 유사하게 추진되는 사업의 경우 기관들 간 시스템 불일치 및 자격검증 지연의 문제 등에 기인한 중복신청 확인이 미흡할 수 있으며 이로 인한 중복수급이 발생할 수 있다. 본 논문에서는 여러기관에서 진행되는 복지서비스 유사사업 관련 중복수급 방지를 위하여, 기관 간 데이터 관리 및 공유의 문제점을 검토하고 블록체인기술의 적용방법을 단계별로 제안하였다. 본 논문의 제안을 통하여 수급대상자의 투명한 데이터 관리가 가능하며 이를 통하여 신뢰기반의 복지급여 관리가 가능할 것이다.

• 한국산림과학회지
• /
• 제98권3호
• /
• pp.311-318
• /
• 2009

본 연구는 GIS를 이용하여 산림 바이오 에너지에 대한 공급 및 수요의 잠재량을 파악하고, 잠재지도 제작을 목적으로 하였다. 산림이 많고, 지리적으로 같은 위치에 해당하는 강원도 영동 지방 4개 시군(고성군, 양양군, 강릉시, 삼척시)을 연구 지역으로 선정하였으며, 수치 임상도의 임상과 영급정보, 통계연보의 가구수 정보를 GIS 자료 형태로 전환한 후 산림 바이오에너지의 잠재된 공급량과 수요량을 파악하였다. 숲가꾸기사업 계획을 기초로 가구수를 고려한 수요대비 잠재적 공급가능량은 약 3,144 Tcal로써, 시군단위에 상관없이 초과공급이 가능한 것으로 나타났으나, 강원도의 평균 수집률인 10%를 고려하면, 시의 경우 6%, 군은 15% 공급 가능한 것으로 나타났다. 한편, 수집률 변화에 따른 공급가능성을 비교한 결과, 60% 이상인 경우, 초과공급이 가능한 지역이 발생하였다.