• 제목/요약/키워드: Periodic Review System

검색결과 68건 처리시간 0.033초

A Sufficient Condition for the Independence of Non-Stationary Demand Process and Inventory Position Process under < Q, r > Systems

  • Sung, C.S.
    • 대한산업공학회지
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    • 제8권1호
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    • pp.22-28
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    • 1982
  • Under a continuous-review inventory system, the inventory position process was proved to be asymptotically independent of the general renewal demand processes, when the two processes form an asymptotic unimodel joint distribution. The analytical technique implemented through this work seems to be more like general, and so the periodic-review system can be similarly investigated. In conclusion, the results may be evaluated to direct to the analytical analyses of some inventory systems which have been treated under some restrictions on demand processes.

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Channelopathies

  • Kim, June-Bum
    • Clinical and Experimental Pediatrics
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    • 제57권1호
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    • pp.1-18
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    • 2014
  • Channelopathies are a heterogeneous group of disorders resulting from the dysfunction of ion channels located in the membranes of all cells and many cellular organelles. These include diseases of the nervous system (e.g., generalized epilepsy with febrile seizures plus, familial hemiplegic migraine, episodic ataxia, and hyperkalemic and hypokalemic periodic paralysis), the cardiovascular system (e.g., long QT syndrome, short QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia), the respiratory system (e.g., cystic fibrosis), the endocrine system (e.g., neonatal diabetes mellitus, familial hyperinsulinemic hypoglycemia, thyrotoxic hypokalemic periodic paralysis, and familial hyperaldosteronism), the urinary system (e.g., Bartter syndrome, nephrogenic diabetes insipidus, autosomal-dominant polycystic kidney disease, and hypomagnesemia with secondary hypocalcemia), and the immune system (e.g., myasthenia gravis, neuromyelitis optica, Isaac syndrome, and anti-NMDA [N-methyl-D-aspartate] receptor encephalitis). The field of channelopathies is expanding rapidly, as is the utility of molecular-genetic and electrophysiological studies. This review provides a brief overview and update of channelopathies, with a focus on recent advances in the pathophysiological mechanisms that may help clinicians better understand, diagnose, and develop treatments for these diseases.

CANDU형 원전 경년열화 감시시스템(Aging Monitor) 개발 (Development of CANDU Reactor Aging Monitor)

  • 김홍기;최영환;고한옥
    • 한국압력기기공학회 논문집
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    • 제5권2호
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    • pp.13-19
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    • 2009
  • As the operating time in nuclear power plants (NPPs) increases, the integrity of nuclear components may be continually degraded due to aging effects of systems, structures and components. Recently, a number of NPPs are being operated beyond their design life to produce more electricity without shutting down. The critical issue in extending a lifetime is to maintain the level of safety during the extended operation period while satisfying the international regulatory standards. Therefore, it is beneficial to build a monitoring system to measure an aging status. In this paper, the Aging Monitor (AM) based on lots of aging database obtained from the operating plants and research results on the aging effects was developed to monitor, manage and evaluate the aging phenomena systematically and effectively in NPPs. The AM for the CANDU is divided into 6 modules: (1) Aging Alarm/Coloring Monitor, (2) Aging Database, (3) Aging Document, (4) Real-time Integrity Monitor, (5) Surveillance and Inspection Management System, and (6) Continued Operation and Periodic Safety Review (PSR) Safety Evaluation. The proposed system is expected to provide the integrity assessment for the major mechanical components of an NPP under concurrent working environments.

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구매 종속적 수요에 대한 접근방법의 고찰 (A Systematic Approach to the Purchase Dependence)

  • 박창규
    • 산업경영시스템학회지
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    • 제43권1호
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    • pp.70-78
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    • 2020
  • Under the situation which customer orders are cancelled unless all products in the order are delivered all at once, this paper concentrates on the purchase dependent demands and explores the systematic approach to implant the purchase dependence into the multi-product inventory model. First, by acknowledging that it is a challenging task to formulate a suitable inventory model for the purchase dependence, we derive the optimal solution condition using an EOQ model and extend the optimal solution condition to periodic review models. Then, through the comparison simulation of four inventory policies regarding several degrees of purchase dependence, we demonstrate that the inventory models which consider the purchase dependence generate less total cost than the inventory models which ignore the purchase dependence. In general, the inventory models which consider the purchase dependence reduce the loss of sales by maintaining more inventories, which results in reducing the total cost. Consequently, the simulation result supports the effectiveness of this paper's approach. In addition, this paper uses the individual order period and joint order period obtained from the EOQ model for the multi-product inventory model. Through the in-depth analysis of comparing the two models, we observe that the model of using the joint order period produces less total cost when the degree of purchase dependence is high, but the model of using the individual order period produces less total cost when the degree of purchase dependence is low.

Genetic diagnosis of systemic autoinflammatory diseases and underlying primary immunodeficiency

  • Seung Hwan Oh
    • Journal of Genetic Medicine
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    • 제19권2호
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    • pp.57-62
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    • 2022
  • Systemic autoinflammatory diseases (SAIDs) are characterized by unprovoked inflammatory episodes such as recurrent/periodic fever, serositis, skin lesions, abdominal symptoms, arthritis/arthralgia, and central nervous system involvement. Genetic diagnosis of SAIDs has been challenging because disease manifestations overlap among themselves and with other immunological disease categories, such as infection and autoimmune diseases. However, the advent of next-generation sequencing (NGS) technologies and expanding knowledge about the innate immunity and inflammation have made the routine genetic diagnosis of SAIDs possible. Here, we review the recurrent/periodic fevers, other recently identified autoinflammatory diseases, and type I interferonopathies, and discuss the clinical usefulness of NGS targeted sequencing for SAIDs, and recent advance of understandings for this heterogeneous disease group as for underlying primary immunodeficiency.

마모 수준에 의거한 예방 정비 모형 (A Preventive Maintenance Model Based on the level of item degradation)

  • 구자항;김원중
    • 산업경영시스템학회지
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    • 제15권26호
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    • pp.173-179
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    • 1992
  • This paper is concerned with preventive maintenance model for the items whose failures are dependent on their wear level. The previous maintenance models have used time as their decision variable, but it is not appropriate for the case which have wear dependent processes for their failures. In this paper, we consider an operating item which is under periodic review and which is subject to degradation. The scheduled maintenance (overhaul ) is based on the level of item degradation rather time. A functional equation for the total expected cost over an infinite horizon period is formulated and solved.

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도로에 대한 투자가 제조업 물류비에 미치는 영향에 대한 연구 -SP 기법 활용- (The Effect of Road Investment on Logistics Cost in Manufacturing Industry -Investigation of the Investment Effects Using Stated Preference-)

  • Chung, Il-Young
    • 대한교통학회지
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    • 제17권1호
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    • pp.41-52
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    • 1999
  • '90년대 들어 미국을 중심으로 Double Counting 문제와 Keynesian/Neo-classical economics theory 까지 연계되어 교통투자가 경제성장에 거의 영향을 주지 않는다는 이론과 영향을 많이 준다는 상충되는 연구결과가 계속 발표되었다. 본 논문은 교통에 대한 투자가 경제성장에 미치는 영향을 계량적으로 분석한 것이다. 범위를 좁혀 도로에 대한 투자가 생산성 즉 제조업체의 물류비에 미치는 영향을 Stated Preference Technique를 이용하여 분석한 것이다. 도로이용 승객의 시간가치를 추정하는 일반적인 Cost/Benefit Analysis와는 달리 화물수송과 관련된 투자효과를 분석하였다. 먼저 도로에 대한 투자가 화물의 수송시간절약과 그에 따른 창고시설, 재고관리등에 미치는 영향을 continuous review system과 periodic review system으로 나누어 이론적으로 고찰하였다. 또한 본 논문에서는 Utility Model에 기초하여 시간가치(value of time)와 화물도착의 정확성 (value of reliability)을 도착지별(depot/consumer)과 상품별로 econometrics 기법을 활용 분석한 후 영국의 COBA와 비교 검토하였다. 종합적으로 도로에 대한 투자가 시간절약, 운행비용절감, 사고비용절감 등 직접적인 효과(direct benefit)외에 depot감소, 운행차량감소, 재고비용절약, 유휴자원의 활용 등(secondary benefits)을 통하여 경제성장에 긍정적인 영향을 끼치고 있는 것으로 나타났다.

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