• Nuclear Engineering and Technology
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• v.41 no.5
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• pp.655-676
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• 2009

The first-ever integral effect test for simulating a guillotine break of a DVI (Direct Vessel Injection) line of the APR1400 was carried out with the ATLAS (Advanced Thermal-hydraulic Test Loop for Accident Simulation) from the same prototypic pressure and temperature conditions as those of the APR1400. The major thermal hydraulic behaviors during a DVI line break accident were identified and investigated experimentally. A method for estimating the break flow based on a balance between the change in RCS inventory and the injection flow is proposed to overcome a direct break low measurement deficiency. A post-test calculation was performed with a best-estimate safety analysis code MARS 3.1 to examine its prediction capability and to identify any code deficiencies for the thermal hydraulic phenomena occurring during the DVI line break accidents. On the whole, the prediction of the MARS code shows a good agreement with the measured data. However, the code predicted a higher core level than did the data just before a loop seal clearing occurs, leading to no increase in the peak cladding temperature. The code also produced a more rapid decrease in the downcomer water level than was predicted by the data. These observable disagreements are thought to be caused by uncertainties in predicting countercurrent flow or condensation phenomena in a downcomer region. The present integral effect test data will be used to support the present conservative safety analysis methodology and to develop a new best-estimate safety analysis methodology for DVI line break accidents of the APR1400.

• Proceedings of the Safety Management and Science Conference
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• 2005.11a
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• pp.135-139
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• 2005

오늘날 국제화 글로벌시대의 도래, 정보기술의 진전으로 인한 인터넷보급의 확대로 인한 시장 환경이 급속하게 변화됨에 따라 공급체인 파트너들 간의 긴밀한 협력관계 구축의 필요성이 요구되는 상황에서 벤더에 의한 재고관리(VMI: Vendor Managed Inventory)는 시장변화에 신속하게 대응하고 기업간의 투명성을 제고하여 재고삭감의 문제를 해결하는 확실한 방법으로 조달 및 생산 물류관리의 가치를 제공하는 도구로 각광받고 있다. 지난 '98년 국내 최초로 유통업체인 롯데마그넷이 VMI를 도입한 이래로 제조 및 유통업체 및 전 부문으로 확산되고 있으며, 특히 전자 전기 자동차 제조업체의 도입 파급효과로 인하여 수직종속적인 구조관계에 있는 중소부품업체에서도 필요성을 인식하게 되었으며 최근 들어 VMI 도입을 시도하고 있다. 본 연구의 목적은 중소부품제조멉체의 VMI의 적용에 의한 물류성과에 관하여 영향을 미치는 효과, VMI의 활동요소와 성공요소와의 상관관계를 검증하고자 하였다. 본 연구는 VMI의 도입 적용을 준비 검토하고 있거나, VMI의 도입적용상 당면문제에 직면하고 있는 기업가, 실무담당자에게 문제해결을 위한 지침을 제공하고, 관련연구단체 및 기관, 학계의 연구자 및 학생들에게 새로운 방향을 제시하는데 의의가 있다.

• Journal of the Korea Safety Management & Science
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• v.3 no.3
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• pp.55-64
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• 2001

The main objective of this research is to develop a model to select the optimal input service level for a distribution center-multi branch inventory distribution system. With the continuous review policy, the distribution center places an order for specific order quantity to an outside supplier, and the order quantity is replenished after a certain lead time Also, each branch places an order for particular order quantity to the distribution center to satisfy the customer demands, and receives the replenishment after a lead time. When an out of stock condition occurs during an order cycle, a backorder is placed to the upper level to fill the unfilled demands. With these situation, variable demand and variable lead time are used for better industrial practice. Further, actual lead times with a generic lead time distribution are used in developing the control model. Under the actual lead time model, the customer service measures actually attained for the distribution center and each branch are explained as the effective customer service measures. Thus, throughout the optimal control (using computer search procedures), we can select the optimal input service levels for the distribution center and each branch to attain the effective service levels for each branch which is consistent with the goal level of service for each branch. At the same time, the entire distribution system keeps minimum inventories.

• Nuclear Engineering and Technology
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• v.52 no.6
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• pp.1148-1155
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• 2020

This work presents two different methods for quantifying and propagating the uncertainty associated with fuel composition at end of life for cask criticality calculations. The first approach, the computational approach uses parametric uncertainty including those associated with nuclear data, fuel geometry, material composition, and plant operation to perform forward depletion on Monte-Carlo sampled inputs. These uncertainties are based on experimental and prior experience in criticality safety. The second approach, the data-driven approach relies on using radiochemcial assay data to derive code bias information. The code bias data is used to perturb the isotopic inventory in the data-driven approach. For both approaches, the uncertainty in k_eff for the cask is propagated by performing forward criticality calculations on sampled inputs using the distributions obtained from each approach. It is found that the data driven approach yielded a higher uncertainty than the computational approach by about 500 pcm. An exploration is also done to see if considering correlation between isotopes at end of life affects k_eff uncertainty, and the results demonstrate an effect of about 100 pcm.

• Proceedings of KOSOMES biannual meeting
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• 2004.11a
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• pp.143-149
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• 2004

Recently, RFID technology play a key role to implement ubiquitous sensor network(USN). In this paper, we introduce trends of RFID technology, standardization, and then its applications. The purpose of this work is to suggest prosperous applications of RFID, which is applicable on marine information system, such as ship inventory management, management of container and its contents, sensing of environments within cargo hold, management of fishery boats. In case that RFID technology is utilized on marine information systems, it makes safety at sea and marine environments protection.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.327-333
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• 2014

Changes in the business environment in which intense and sustained growth and survival must meet a variety of customer needs (Q, C, D) and business side of the enterprise for profit structure reformation is absolutely necessary for innovation activities. So far, management of innovation in method BPR, PI, OVA, 6 Sigma, Strategic Purchasing, PPM, SCM etc. are being introduced. However, they have a limit of partial optimization and improvement-oriented techniques. So this paper studied the TPI(Total Profit Innovation) application in order to derive empirical methodology to maximize profitability for the domestic S foundry factory. To this end, long-term gains through structural analysis and intensity analysis to ensure continued growth and profitability strategy are devised through management Innovation analysis. And improvement projects was presented to solve main issues of five categories(Inventory, Sales Mix, Cost, Quality Cost, Skill and Work-load) We will expect the office productivity improvement and financial performance improvement and then continually accumulate and review the results.

• The KSFM Journal of Fluid Machinery
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• v.19 no.2
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• pp.49-54
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• 2016

A conceptual study of an air-cooled heat exchanger is conducted to achieve the long-term passive cooling of an integral reactor. A newly designed air-cooled heat exchanger is introduced in the present study and preliminary thermal sizing is demonstrated. This study mainly focuses on feasibility of an innovative air-cooled heat exchanger to extend the cooling period of the passive residual heat removal system(PRHRS) only in passive manners. A vertical shell-and-tube air-cooled heat exchanger is installed at the top of the emergency cooldown tank(ECT) to collect evaporated steam into condensate, which enables water inventory of the ECT to be kept. Finally, thermal sizing of an air-cooled heat exchanger is presented. The length and the number of tubes required, and also the height of a stack are calculated to remove the designated heat duty. The present study will contribute to an enhancement of the passive safety system of an integral reactor.

• Proceedings of the Safety Management and Science Conference
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• 2002.11a
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• pp.227-232
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• 2002

Enormous flocks by the reduced life cycle of products caused by the technological innovation if later 20 century, development of new materials and diversified demands of customers appeared as the pressing element causing the trouble in management of companies, and when considering the logistic costs that are imposed to companies in terms of function, the costs related to the stock topped the list of costs, followed by the transportation ones, and for pallet pool system, inventory of stocks is very difficult by the number of companies. Reducing the logistic cost may be accomplished by numbers of logistic management methods, but the most fundamental and essential one is the accomplishment of the consistent pallet system that is the core of unit load system, and the purpose of consistent pallet system is the treatment of logistic functions such as transportation, storage and unloading with consistent pallet system, and increasing the turnover ratio is required for the improvement of the system. As the turnover ratios is increased, more pallets will be used so, numbers of empty pallets will be increased accordingly by returning the pallet. Therefore, in this study, we will establish the effective stock management system by comparing with the other existing stock management system after looking at the concept and examples of pallet full system in order to resolved this kind of problem.

• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.193-198
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• 2013

Warehouse Management System was a helper of business in past, but it is perceived as a core competitive power and a tool for generating new business. It have been come out some new prospects for WMS due to generalization of global outsourcing and extension of the range of supply chain. In China, H automobile company construct the new WMS for providing the production extension and increment of part demand for A/S. This paper deals with the location management in warehouse, warehouse management, delivery management of goods from a warehouse, inventory management organizing WMS for construction of A/S warehouse in H motor in China. Then we identified the several problems of existing warehouse and constructed the driving organization and methods for overcoming these problems. We continually gather data for analysing the effects of new A/S warehouse and WMS construction.

• Journal of the Korea Safety Management & Science
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• v.19 no.3
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• pp.109-115
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• 2017

In order to increase the productivity of the logistics center and transportation, we try to articulate the priority ranking factors of the productivity influenced by the personality of the field workers (logistics center workers) and functional workers (drivers) via the AHP technique Individual personality was studied by applying the Big 5 model of psychological factors (openness, Conscientiousness, extroversion, Agreeableness, neuroticism). In this paper, extraversion was critically analyzed as a priority factor. A trait of extroversion is a strongly active and individual personality. In this study, the field workers are logistics center workers and the functional workers are drivers. They are interactively influenced in the In & Out operation. For example, when it comes to 'up and down work' and 'inspection work', the functional workers perform 'up and down work' and 'delivery work' and the field workers perform 'inspection work'. Stressing on the respective work has an affect on work productivity. Inspection workforce has something to do with inventory management. Functional workforce affects the delivery workforce. Delivery work is positively correlated with customer satisfaction. Nevertheless, as a result of research, extrovert personality that has something to do with an energetic activity would not affect on the implementation of their operation. In addition, personal extraversion of workers and drivers in the warehouse can have a significant impact on job commitment and productivity improvement.