• 제목/요약/키워드: inventories

검색결과 370건 처리시간 0.025초

Radiation Monitoring in the Residential Environment: Time Dependencies of Air Dose Rate and 137Cs Inventory

  • Yoshimura, Kazuya;Nakama, Shigeo;Fujiwara, Kenso
    • Journal of Radiation Protection and Research
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    • 제47권1호
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    • pp.30-38
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    • 2022
  • Background: Residential areas have some factors on the external exposure of residents, who usually spend a long time in these areas. Although various survey has been carried out by the government or the research institutions after the Fukushima Daiichi Nuclear Power Plant accident, the mechanism of radiocesium inventory in the terrestrial zone has not been cleared. To better evaluate the radiation environment, this study investigated the temporal changes in air dose rate and 137Cs inventories (Bq/m2) in residential areas and agricultural fields. Materials and Methods: Air dose rate and 137Cs inventories were investigated in residential areas located in an evacuation zone at 5-8 km from the Fukushima Daiichi Nuclear Power Plant. From December 2014 to September 2018, the air dose rate distribution was investigated through a walking survey (backpack survey), which was conducted by operators carrying a γ-ray detector on their backs. Additionally, from December 2014 to January 2021, the 137Cs inventories on paved and permeable grounds were also measured using a portable γ-ray detector. Results and Discussion: In the areas where decontamination was not performed, the air dose rate decreased faster in residential areas than in agricultural fields. Moreover, the 137Cs inventory on paved surfaces decreased with time owing to the horizontal wash-off, while the 137Cs inventory on permeable surfaces decreased dramatically owing to the decontamination activities. Conclusion: These findings suggest that the horizontal wash-off of 137Cs on paved surfaces facilitated the air dose rate decrease in residential areas to a greater extent compared with agricultural fields, in which the air dose rate decreased because of the vertical migration of 137Cs. Results of this study can explain the faster environmental restoration in a residential environment reported by previous studies.

원자재 조립.가공과정을 갖는 건설공사 프로세스의 적정 재고관리 방안에 관한 연구 (Inventory Management in Construction Operations Involving on-site Fabrication of Raw Materials)

  • 임건순;한승헌;정도영;유충규;최석진
    • 한국건설관리학회논문집
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    • 제9권1호
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    • pp.187-198
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    • 2008
  • 건설현장에서는 일반적으로 많은 양의 자재재고를 보유해 왔다. 이러한 자재재고는 현장의 불확실한 수요에 대응하여 공정지연을 방지하고, 원자재 가격 상승으로 인한 비용증가에 대비하는 등 순기능적 측면이 있다. 하지만 과도한 자재재고는 재고보유에 소요되는 재고유지비를 증가시키고 현장물류 공간배치의 효율성을 저하시키는 등 낭비요인으로 작용하기도 한다. 따라서 현장의 다양한 변동성을 고려하여 적정 자재재고 수준을 결정하고 관리하는 것은 건설공사의 효율성 측면에서 매우 중요한 요소이다. 본 연구는 시스템 접근방법의 절차에 의하여 철근가공 조립공정과 같이 현장에 투입되기 이전에 원자재 조립 가공과정을 갖는 건설 프로세스론 분석하고 이러한 흐름과정에서 재고수준을 적정화하는 알고리즘을 제시하였다. 이러한 재고관리 방안의 적용성을 확인하기 인하여 수도권지역 경전철 건설사업의 철근 가공장에서의 재고관리 사례를 분석하였다. 본 연구에서 제안한 알고리즘을 적용한 결과, 현장의 실제 철근 소요량과 가공장에 입고되는 철근 원자재의 입고량이 균형을 이루었고, 이에 따라 평균 재고량과 재고유시비용이 크게 감소되는 것으로 나타났다.

습지총량제 도입에 따른 문제점과 개선방안에 대한 연구 (Studies on Problems and Improvement of Introducing No Wetland Loss)

  • 김윤정;이상돈
    • 환경영향평가
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    • 제18권4호
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    • pp.235-243
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    • 2009
  • Wetlands considered to be an important natural resources because they provide biodiversity and habitat for species to breed and survive. In this regard, many countries in the world provide wetlands and have policies and laws to protect them. In Korea we hosted RAMSAR COP-10 at Changwon in 2008 representing Korea's endeavor to wetland protection. But, in the process of development Wetlands are easy target to be lost due its easy access and the laws and regulations to protect them are relatively weak. Thus, this research focused on the introduction of No Wetland Loss(NWL) and we can achieve wetland protection in the economy market ways. Thus, NWL should consider 1) a clear definition of NWL and harmony and consensus of introduction of NWL, 2) considering most wetlands be private we need a financial support for securing wetlands, 3) inventories for wetlands in Korea, draw a line of demarcation, technic to evaluate wetlands, 4) wetland restoration considering function of ecosystem not total amount of wetlands. Wetland protection should be a part of Basic Law of Water Management which in its progress and we need further studies on wetland protection because of watershed management, deserted agricultural paddies, etc.

시뮬레이션을 이용한 아연공장의 생산통제 방안의 결정 (A Decision of the Production Control Policy using Simulation in Zinc Manufacturing Process)

  • 김준모;김연민
    • 산업공학
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    • 제21권4호
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    • pp.418-434
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    • 2008
  • This paper studied issues in decision making on the production control policy of a cathode plate manufacturing process in zinc refining plant. The present production system has a long lead time from raw materials (aluminum plate) to products (cathode plate) due to many WIP inventories. Because WIP inventories are stocked at each process and moved from one place to another frequently, they are the main cause of inefficiency in the process. In this paper, to solve this problem, several production control policies have been identified and studied. Several simulation models are used to compare the performances of these production control policies. The output lead time and WIP (Work In Process) of real production system are compared with those of simulation models. PUSH, CONWIP, DBR, KANBAN and CONWIP-DBR models have been used to simulate and review the optimized production control policy that achieves the target output quantities with decreased lead time and WIP. The simulation results of each production control policy show that CONWIP and CONWIP-DBR models are the good production control policy under the present production system. Especially in present production system, CONWIP with one parameter is easier control policy than CONWIP-DBR with two parameters. Therefore CONWIP has been selected as the best optimum production control policy. With CONWIP, lead time has been reduced by 97% (from 6,653 to 187 minute) and WIP has been reduced from 1,488 to 53, compared to the present system.

대학단위 온실가스 인벤토리 구축 가이드라인 개발 (Development of the Guideline Applied for University on GHG Emission Inventory)

  • 신은섭;정혜진;이승묵
    • 한국대기환경학회지
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    • 제28권3호
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    • pp.316-324
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    • 2012
  • This research shows the improved methodology which can be applied for universities which want to set up their GHG inventories. In other words, we tried to make guideline in problems due to the unique characteristics of universities. This guideline will help university to deal with the problems they are facing: For example university has less enforcement in operational control compared to the business sector. And it also has various usage of facilities, although these facilities are not maintained by same principal agent. The difference between owner and manager is an another reason for difficulty in setting group organization. The improved and adaptable methods responding to these problems were suggested from this research. The results of this research says the new definition of function for various actors in university for quality control and quality assurance. Because the suggestions made in this research which concerns with criteria for building of universities' GHG inventories were all read by current legislation, there is an anticipation that this can be an official guideline that can be applied to the universities right away.

신생아에 대한 산모의 감지도에 관한 연구 (A Study on the Maternal Perception of Her Newborn Baby)

  • 박영숙;변희재
    • 대한간호학회지
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    • 제14권1호
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    • pp.50-59
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    • 1984
  • The purpose of this study was to evaluate the maternal perception of her newborn and identify the risk of mother-infant relationship. Broussard's Neonatal Perception Inventories were completed by 113 mothers on the first or second postpartum day (Time I ) while they were still in the University Hospital. These inventories were again administered when the infants were approximately one month of age (Time Ⅱ). The data was analyzed by S.P.S.S. program and the results were as follows: 1) There were differences between the mothers' exportations of the average baby and perceptions of their babies at Time I and Time Ⅱ (p<0.01). 2) The maternal perception of her newborn at Time I was not related with the education, the parity, the experience of abortion, the type of delivery and the sex of baby but related with the method of feeding (p<0.05). 3) The maternal perception of her newborn at Time Ⅱ was not related with the education, the parity, the experience of abortion, the type of delivery and the method of feeding but related with the sex of baby (p<0.05). 4) The changes of maternal perception between Time I and Time Ⅱ were not related with the education, the parity, the experience of abortion, the method of delivery and the sex of baby but related with the method of feeding (p<0.1). 5) The maternal perception of the newborn was not correlated with the age and the duration of labor.

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US Purchasing Managers' Index and its Impact on Korea and US

  • Jeon, Ji-Hong
    • 유통과학연구
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    • 제15권3호
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    • pp.17-25
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    • 2017
  • Purpose - The study is to examine the impact of the US Purchasing Managers' Index (PMI) on Korea and the US industrial economy including the distribution industry. We analyze its effect on the industrial economy centered on the distribution industry using economy indices in Korea and the US. Research design, data, and methodology - The variables are used to analyze the dynamic relationship which occurs among the US PMI, the industrial production index, producer price index, unemployment rate, and manufacturing Inventories Index in Korea and the US from January 1990 to July 2016 using Vector Error Correction Model. Results - As a main result, the impact of the US PMI on all the economy indices both Korea and the US has the same cyclical movement. The US PMI is positively related to the producer price and the industrial production index of Korea and the US, while it is negatively related to unemployment rate, and the manufacturing inventories index in Korea and the US. Conclusions - The US PMI as an advanced index has a power to predict the economies on Korea and the US. In the end, we find that the US PMI has a great impact on Korea and the US industrial economy.