• Title/Summary/Keyword: Deteriorating items

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Collaboration Inventory System with Limited Resources and Weibull Distribution Deterioration

  • Wee, Hui-Ming;Law, Sh-Tyan;Yu, Jonas
    • Industrial Engineering and Management Systems
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    • v.6 no.1
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    • pp.1-10
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    • 2007
  • The objective of this study is to develop an optimal joint cost from the perspectives of both the manufacturer and the retailer. The integrated production-inventory model with Weibull distribution deteriorating items is assumed to have a constant demand rate. A limited retailer storage space and multiple delivery per order are considered in this model. A numerical example including the sensitivity analysis is given to validate the results of the production-inventory model.

Dynamic Production-Inventory Scheduling Model for Deteriorating Items with Expediting Cost (특급비용을 고려한 진부화 제품의 동적 생산-재고 모형)

  • Choe, Yeong-Jin;Kim, Man-Sik
    • Journal of Korean Society for Quality Management
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    • v.17 no.1
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    • pp.116-124
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    • 1989
  • A multi-period production-inventory scheduling model, which extends the customary dynamic lot sizing model to the one for deteriorating items, is developed. The amount of deterioration during a period is assumed to be proportional to the on-hand inventory at the end of the period. It is futher assumed that the deterioration rates vary from period to period. In addtion, an expediting cost due to the delay of outstanding order is included and it is allowed to offset the order release date in advance, instead, in order to avoid incurring the cost. Finally, a quasi-WW algorithm corresponding to the Wagar-Whitin algorithm is proposed to obtain the optimal production-inventory schedules.

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Multi-Stage Production-Inventory Planning for Deteriorating Items

  • Choi, Young Jin;Kim, Man Shik
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.10 no.16
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    • pp.113-119
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    • 1987
  • A Multistage production-inventory model is developed for deteriorating items. The model is developed deterministic but time-varing demand pattern and instantaneous delivery. Deterioration rates are assumed to vary from period to period. Discrete version of Pontryagin's maximum principle is used to present the efficient alogrithm to solve this model easily. A numerical example is given to illustrate the derived results.

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An Optimal Production Run Length in A Deteriorating Machine (퇴화하는 기계에서의 품질 불량을 고려한 최적 생산시간 결정)

  • Kim, Chang-Hyun;Hong, Yu-Shin
    • Journal of Korean Institute of Industrial Engineers
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    • v.22 no.3
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    • pp.351-364
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    • 1996
  • This paper presents on EMQ model which determines an optimal production run length in a deteriorating machine. It is assumed that a machine is subject to a random deterioration from an in-control state to an out-of-control state with on arbitrary distribution and thus producing some proportion of defective items. An optimal production run length and a minimum average cost are derived in each of three deteriorating processes; constant, linearly increasing, and exponentially increasing. The model with repair cost is also analyzed. Several mistakes in previous research are found and discussed. Numerical experiments are carried out to see the behavior of the proposed model depending on the cost factors as well as machine parameters, and some interesting behaviors are observed.

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An optimal production run length in a deteriorating machine (퇴화하는 기걔에서의 품질 불량을 고려한 최적 생산시간 결정)

  • 김창현;홍유신
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1996.04a
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    • pp.290-293
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    • 1996
  • This paper presents an EMQ model which determines an optimal production run length in a deteriorating machine. It is assumed that a machine is subject to a random deterioration from an in-control state to an out-of-control state with an arbitrary distribution and thus producing constant proportion of defective items. An average cost function and an optimal production run length are determined. A mistake in previous model is found and discussed. A mistake in previous model is found and discussed. Numerical experiments are carried out to see the behavior of the proposed model depending on the cost factors as well as machine parameters, and some interesting behaviors are observed.

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An Optimal Production Cycle and Inspection Schedules in A Deteriorating Machine (품질 불량을 고려한 최적 검사계획 및 생산시간 결정)

  • Kim, Chang-Hyun;Hong, Yu-Shin
    • Journal of Korean Institute of Industrial Engineers
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    • v.23 no.2
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    • pp.261-273
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    • 1997
  • This paper presents an EMQ model which determines an optimal production cycle and inspection schedules simultaneously in a deteriorating machine. It is assumed that a machine is subject to a random deterioration from an in-control state to an out-of-control state and thus producing some proportion of defective items. Optimal solutions and minimum average cost as well as some unique properties are derived. Numerical experiments are carried out to examine the behavior of the proposed model and compare the proposed model to the existing models. Several mistakes in the previous research are found and discussed.

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A Study on the Improvement Policy of the Localization Parts of the Defense Sector (국방분야 부품국산화개발 정책개선 방안)

  • Jung, Suk-Yun;Eom, Jung-Ho
    • Journal of National Security and Military Science
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    • s.15
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    • pp.117-151
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    • 2018
  • The development of local defense parts has played a role a pure function such as maintenance of stable procurement source of military goods, provision of timely supply, establishment of self-defense base, creation of import substitution effect considering the whole life-cycle cost, reduction of foreign currency and protection of domestic defense industry. However, as the development success rate is deteriorating, it is time to analyze the related policies and improve the system. In order to improve the success rate of development of parts for the defense sector, it is necessary to unify the separated policies by the development-related departments and strengthen the policy support for the development companies to actively participate in the development. In addition, it is necessary to improve the paradigm for the selection of development items and change the authority of selecting development items and to delegate authority to create synergies. Parts localization development policy improvement is military support side it will contribute to strengthening defense power management by organically combining with technological development aspect and economical aspect. Development items will be linked to defense exports, which will have a remarkable effect on sales growth and job creation effects. The development of local defense parts is spreading.

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Supply Chain Inventory Model for Items with Stock Dependent Demand Rate and Exponential Deterioration under Order-Size-Dependent Delay in Payments (주문량 종속 신용거래 하에서 재고 종속형 제품수요를 갖는 퇴화성제품의 공급체인 재고모형)

  • Shinn, Seong Whan
    • Journal of the Korea Safety Management & Science
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    • v.17 no.3
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    • pp.279-287
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    • 2015
  • 본 연구는 공급자(supplier), 중간공급자(distributor) 그리고 고객(customer)으로 구성된 2 단계 공급사슬에서 퇴화성 제품(deteriorating products)에 대한 중간공급자의 재고모형을 분석하였다. 문제 분석을 위해 공급자는 중간공급자의 수요 증대를 목적으로 중간공급자의 주문 크기에 따라 차별적으로 외상 기간을 허용하고, 최종 고객의 수요는 중간공급자의 재고 수준에 따라 선형적(linearly)으로 증가한다는 가정 하에 모형을 분석하였다. 중간공급자의 이익을 최대화하는 경제적 주문량 결정 방법을 제시하였고, 예제를 통하여 그 해법의 타당성을 보였으며, 민감도 분석을 통하여 퇴화율이 재고정책에 미치는 영향을 분석하였다.

A Survey of Korean Medical Doctors on the Items and Importance of Lifestyle Management for Infertile Couple (난임 부부의 섭생 지도 항목과 중요도에 대한 한의사 대상 설문조사)

  • Yu-Kyung Jeong;Dong-Il Kim;Young-Jin Yoon;Jang-Kyung Park
    • The Journal of Korean Obstetrics and Gynecology
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    • v.36 no.3
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    • pp.114-128
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    • 2023
  • Objectives: This study was conducted to reflect Korean Medicine doctors (KMD)' perception of lifestyle management in the process of developing a Korean Medicine (KM) Clinical Practice Guidelines (CPG) of female infertility. Methods: We sent four e-mails containing links to online questionnaires to 25,286 KMD belonging to the Association of Korean Medicine. The questionnaire consisted of sexual intercourse, weight, diet, exercise, drinking, smoking, caffeine intake, stress etc. KMD responded to self-administered questionnaires, and we analyzed 786 responds. Results: KMD put stress first among the infertile women's lifestyle management items, weight and sexual intercourse were next. Also KMD put stress first among the spouses' lifestyle management items, drinking and sexual intercourse were next. In relation to sexual intercourse, 'Recognizing the Fertile Window' was the most important. In relation to stress in the emotional domain, 'Depression' and 'Anxiety' were the most important, and in relation to stress in the relationship domain, 'Deteriorating of marital relationship' was the most important. Conclusions: We surveyed the status of KMD' awareness of infertility lifestyle management for patient education, and reflected it in the modification of the CPG for female infertility.

A Study on Relations between Deterioration of Physical Functions due to Aging and Bathroom Design Guidelines for the Elderly (노화로 인한 신체적 기능 쇠퇴와 고령자를 위한 욕실 디자인 가이드라인 관계 연구)

  • Lee, Yeun-Sook;Lim, Hyun-Jin;Lee, Ji-Hye;Ahn, Chang-Houn
    • Korean Institute of Interior Design Journal
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    • v.22 no.5
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    • pp.188-198
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    • 2013
  • Advancement toward aging society has presented the importance of house planning in consideration of the elderly, increasing the necessity of such planning. Therefore the importance of indoor design guideline for elderly houses has been stressed and the understanding of the aging in regard to this trend will create more mature spaces. In line with this trend the purpose of this study is to study the medical factors related with bathroom interior design guidelines of the existing elderly houses from the viewpoint of deteriorating physical functions due to aging process. In order to research the deterioration of physical functions due to aging literatures of medical and exercise physiology were used and concerning the existing bathroom design guidelines for the aged people, the guideline items of behavior facilitation, physiological maintenance and perceptual maintenance aspects out of Murtha & Lee's user benefit criteria(1976) related with physical functions were selected to research in relation with the knowledge about the deterioration phenomena of physical functions. Physical aging and deterioration aspects were classified from the viewpoint of musculoskeletal disorder, cardiovascular disorder, respiratory disorder, gastronomy disorder, urology disorder, somatosensory disorder, endocrine disorder, immune disorder, nervous disorder and skin diseases and these were utilized in interpreting total 100 items of bathroom design guideline. Because bathroom is the space where many physical movements are done, it had the closest relationship with the deterioration of musculoskeletal health in general and as bathroom is the space where people use water and feel the difference in temperature and moisture more than other spaces, deterioration of skin and somatosensory health had the next closest relationship. The result of this study revealed that regarding the deterioration of physical functions of the elderly people in aspect of their perceptibility as designers will design creatively and sincerely based on its relationship with nervous system in future, the result of this study will be used to develop better spatial designs efficiently to meet for the aging society.