• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.33
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• pp.87-92
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• 1995

This paper proposes age replacement policy in stepdown warranty policy. The replacement policy is considered in case of minimally repairable items. And renewal theory is used in analyzing warranty costs. The expected cost per unit time is presented in stepdown warranty policy, free replacement, prorata and hybrid policy. In this article it is assumed that item is replaced at the age of T but the any failure is minimally repaired before the age T. At this point the expected cost per unit time is shown in customer's view point. And numerical example is explored in weibull time-to-failure distribution.

• International Journal of Reliability and Applications
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• v.11 no.2
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• pp.107-122
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• 2010

This paper deals with the reliability analysis of a complex system, which consists of two subsystems A and B connected in series. Subsystem A has only one unit and B has two units $B_1$ and $B_2$. Marked process has been applied to model the complex system. Present reliability model incorporated two repairmen: supervisor and novice to repair the failed units. Supervisor is always there and the novice remains in vacation and is called for repair as per demand. The repair rates for supervisor and novice follow general and exponential distributions respectively and the failure time for both the subsystems follows exponential distribution. The model is analyzed under "Head of line repair discipline". By employing supplementary variable technique, Laplace transformation and Gumbel-Hougaard family of copula various transition state probabilities, reliability, availability and cost analysis have been obtained along with the steady state behaviour of the system. At the end some special cases of the system have been taken.

• Journal of the Korean Data and Information Science Society
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• v.27 no.6
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• pp.1557-1564
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• 2016

Recently, an extended warranty of a system following the expiration of the basic warranty is becoming increasingly popular to the user. In this respect, we suggest a two stage maintenance policy under the non-renewing warranty from the user's point of view in this paper. In the first stage, the user has to decide whether or not to purchase the extended warranty period. And, in the second stage, the optimal replacement period following the expiration of the warranty is determined. Under the extended warranty, the failed system is minimally repaired by the manufacturer at no cost to the user. We utilize the expected cost from the user's perspective to determine the optimal two stage maintenance policy. Finally, a few numerical examples are given for illustrative purpose.

• International Area Studies Review
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• v.22 no.2
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• pp.93-119
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• 2018

During the period from 2004 to 2013, the China's automobile consumer protection policy-making reflected interest articulation and aggregation among consumers, manufacturers, car dealership and repair companies. In particular, consumers has succeeded in articulating their interests in spite of their dispersed situation by making the efforts to present regulation's revision agenda through the China Consumers Association. And the car dealers put the right to blame the car manufacturers for unexpected vehicle defects into the final regulation through the China Automobile Distribution Association. Finally, due to the active interest articulation of automobile companies, policy making process was delayed or policies that were expected to benefit consumers were promoted to some extend. Therefore, it can be seen that there is a limit to define state-society relations in China simply as state corporatism, and rather it is more important to understand state-society relations in China as between state corporatism and societal corporatism including bottom-up interest articulations and aggregations and policy modification activities of various private or societal organizations.

• Journal of Korean Society for Quality Management
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• v.31 no.3
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• pp.193-204
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• 2003

In this paper, we consider a periodic preventive maintenance(PM) policy in which each PM reduces the hazard rate but remains the pattern of hazard rate unchanged. And the system undergoes only minimal repairs at failures between PM's. The expected cost rate per unit time is obtained. The optimal number N of PM and the optimal period x, which minimize the expected cost rate per unit time are discussed. Explicit solutions for the optimal periodic PM are given for the Weibull distribution case.

• Industrial Engineering and Management Systems
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• v.2 no.1
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• pp.63-70
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• 2003

In this study, we employed an arithmetic process (AP) approach to resolve gearbox maintenance problems. The approach is realistic and direct in modelling the characteristics of a deteriorating system such as a gearbox since a decreasing AP can model a gearbox's successive operating times and an increasing AP can model the corresponding consecutive repair times. First of all, two test statistics were used to check whether the process is arithmetic or not. Next, model parameters of the AP were estimated using the simple linear regression method. Finally, the optimal replacement policy based on minimising the long-run average cost per day was determined for each type of gearbox.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.2
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• pp.24-31
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• 2018

As a system complexity increases and technology innovation progresses rapidly, leasing the equipment is considered as an important issue in many engineering areas. In practice, many engineering fields lease the equipment because it is an economical way to lease the equipment rather than to own the equipment. In addition, as the maintenance actions for the equipment are costly and need a specialist, the lessor is responsible for the maintenance actions in most leased contract. Hence, the lessor should establish the optimal maintenance strategy to minimize the maintenance cost. This paper proposes two periodic preventive maintenance policies for the leased equipment. The preventive maintenance action of policy 1 is performed with a periodic interval, in which their intervals are the same until the end of lease period. The other policy is to determine the periodic preventive maintenance interval minimizing total maintenance cost during the lease period. In addition, this paper presents two decision-making models to determine the preventive maintenance strategy for leased equipment based on the lessor's preference between the maintenance cost and the reliability at the end of lease period. The structural properties of the proposed decision-making model are investigated and algorithms to search the optimal maintenance policy that are satisfied by the lessor are provided. A numerical example is provided to illustrate the proposed model. The results show that a maintenance policy minimizing the maintenance cost is selected as a reasonable decision as the lease term becomes shorter. Moreover, the frequent preventive maintenance actions are performed when the minimal repair cost is higher than the preventive maintenance cost, resulting in higher maintenance cost.

• Journal of Korean Society for Quality Management
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• v.42 no.1
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• pp.1-14
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• 2014

Purpose: In this paper, the minimal repair-replacement warranty policy is used to carry out a warranty cost analysis with warranty servicing times and failure times that are statistically correlated to bivariate distributions. Methods: Based on the developed approach by Park and Pham (2012a), we investigate the property of the Freund's bivariate exponential distribution and obtain the number of warranty services using the field data to conduct the warranty cost analysis. Results: Maximum likelihood estimates are presented to estimate the parameters and the warranty model is investigated using a Freund's bivariate exponential distribution. A numerical example is discussed to deal with the applicability of the developed approach in the paper. Conclusion: A novel approach of analyzing the warranty cost is proposed for a product in which failure times and warranty servicing times are used simultaneously to investigate the eligibility of a warranty claim.

• Fashion & Textile Research Journal
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• v.19 no.4
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• pp.373-384
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• 2017

This research has its significance on contributing to the establishment of sustainable fashion industry ecosystem of Seongsu area based on the creativity which is the driving force of economic growth in the 21st century. This study reviewed the major activities and processes of Seongsu-dong's regional specialized industries project and the social economic organizations's creation of fashion clusters by using specialized books, previous research, press releases such as newspapers, magazines, and the specialized internet site(www.seoul.go.kr). Also street casual-style clothes were designed based on work-wear that themed Seongsu-dong's industrial scene and social problems. The results of this study are as follows. Seongsu-dong represents the political and economic characteristics of a typical semi-industrial area in which the automobile repair, printing, textile, leather, and handmade industries are concentrated in accordance with the government's business and policy, and shows the technical characteristics through the internal complete industrial ecosystem integration of the handmade industries. In addition, social and cultural characteristics such as various local activities based on creativity are shown by social enterprises, and cultural artists. Based on the results of analyzing the regional characteristics of Seongsu-dong according to political, economic, technological, socio-cultural characteristics, eight fashion designs were made as motifs reflecting the regional characteristics of Seongsu-dong.

• Journal of the Korean Institute of Educational Facilities
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• v.13 no.3
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• pp.37-47
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• 2006

The conservation or practical use of a lot of closed schools which occurred from 1982 all over the country by governmental policy has been becoming important concerns to local resident and community with economical and administrative interest. A lot of examples, sold or rented to public institutions or a person, which have been using by welfare facilities for inhabitants, facilities for education, youth, company, culture and art, and other use, could be found. It could be said that the process of user's participation of these examples is very high, that is, a lot of examples of our surrounding is applied with ecological concept have participated by most users and local residents directly to architectural repair and renewal process, and practical use. In this background, I choose total five examples more than one by Chungbuk, Chungnam, Jeonbuk, Jeonnam district to investigate examples of closed schools applied ecological architectural concept and I researched reconfiguration of site, change of exterior or interior material, application of ecological system, and role as local community.