• Communications for Statistical Applications and Methods
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• v.18 no.4
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• pp.403-411
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• 2011

This paper deals with a group acceptance sampling plan for time truncated tests which are based on the total number of failures from the whole group assuming that the life time of an item follows the Dagum (inverse Burr) distribution. This study is developed when a multiple number of items as a group can be tested simultaneously in a tester. The minimum number of groups required for a given group size and acceptance number is determined such that the producer and consumer risks are satisfied simultaneously at the specified quality level, while the termination time and the number of testers are specified. Comparisons are made between the proposed plan and the existing plan on the basis of size of the groups. Two real examples are provided.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.8
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• pp.1537-1546
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• 2011

The photovoltaic(PV) generation system have recently become widely used to solve the environmental problems and running out of fossil fuels. However, the study on maintenance is inadequate for PV system. This paper proposes the novel diagnosis method of output power decline to maintain the normal output performance of PV array. The diagnosis method used the proportional relation of irradiation-output current(S-I) of PV array at maximum power point(MPP). And, first order polynomial using the relation is proposed to easily apply PV system. To estimate the relation in case of separation of PV array producer and diagnosis system producer. Kalman Filter algorithm is also proposed at 30.2kW grid-connected PV system. Then, the performance of diagnosis method is evaluated using the hardware tests as well as the simulation.

• Resources Recycling
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• v.12 no.5
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• pp.3-9
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• 2003

In order to prospect current recycling status in Korea, legislative system and policies relating to recycling, wastes generation and recycling rate were reviewed. Approximately 260,400 ton/day of wastes was generated in 2001. 48,400 ton/day of household waste and 212,000 ton/day of industrial waste. During the last ten years, waste management laws such as waste disposal law, recycling law and environment friendly industry law were prepared. In this article, concerning over waste generation and recycling, recycling law, Extended Producer Responsibility System and the problems and technological developments associated with recycling were summarized.

• Journal of Korean Society for Quality Management
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• v.28 no.4
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• pp.204-222
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• 2000

Supply Chain Management is a process-oriented concept, integrated approach to procuring, producing, and delivering products and services to customers. Supply Chain Management covers the management of material, information, and funds flows. A strategic supply chain management produces for value maker and the ultimate customer. One aim of this paper is to determine the effect of contract parameters on the quality of the end product of the supplier-producer chain. The supply chain management is viewed as a single entity rather fragmented. This research constructed model the relationship of supply chain management to quality management. The questionnaire were tested with survey of supplier's employee and the result were analyzed using SEM(Structural Equation Model). As a result, Quality performance positively depends on the communication, coordination, and process management between the supplier and the producer.

• Industrial Engineering and Management Systems
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• v.8 no.3
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• pp.162-170
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• 2009

This paper deals with a closed-loop remanufacturing system with one manufacturer and one remanufacturer. The manufacturer sells new products bearing the 'Extended Producer Responsibility (EPR).' It is assumed that the manufacturer's collection rate of used products depends only on the buy-back cost, while that of the remanufacturer depends on the minimum allowed quality level of used products in addition to the buy-back cost. Through the development of mathematical models with the objective function of maximizing profit, we study an efficient operation policy of each party. The decision variables are the unit selling price of new products and remanufactured products, the unit buy-back cost of the used products of the manufacturer and remanufacturer, and the minimum allowed quality level. The validity of the model is examined through numerical examples and sensitivity analysis.

• International Journal of Reliability and Applications
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• v.15 no.2
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• pp.77-84
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• 2014

In this paper, a optimal designing methodology is proposed to determine the parameters for skip-lot sampling plan of type SkSP-2 plan with double sampling plan as reference plan, when the lifetime of the product follows generalized exponential distribution. The two points on the operating characteristic curve approach are used to find the optimal parameters for the proposed plan. The plan parameters are determined so as to minimize the average sample number subject to satisfying simultaneously both producer and consumer risks at the acceptable and limiting quality levels respectively.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.828-831
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• 2003

Although most of the DOS containing aminoglycosides are produced by Streptomyces, very little information is available about their biosynthesis. In the present paper, we report a method to isolate DOI synthase, a key enzyme in the biosynthesis of DOS, from aminoglycoside producer Streptomyces. PCR primers based on conserved region of DOI synthases were specific and reliable for the isolation of the biosynthetic genes of DOS containing aminoglycosides or the screening of the aminoglycoside producers. The use of DOI synthase as a probe could save both time and cost of cloning aminoglycoside biosynthetic genes.

• Communications for Statistical Applications and Methods
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• v.17 no.1
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• pp.89-98
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• 2010

In this paper, a two-stage group sampling plan based on the time truncated life test is proposed for the Weibull distribution. The design parameters such as the number of groups and the acceptance number in each stage are determined by satisfying the producer's and consumer's risks simultaneously when the group size and the test duration are specified. The acceptable reliability level is expressed by the ratio of the true mean life to the specified life. It was demonstrated from the comparison with single-stage group sampling plans that the proposed plan can reduce the average sample number or improve the operating characteristics.

• Journal of Korean Society of Transportation
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• v.8 no.1
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• pp.17-24
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• 1990

The first-best pricing rule which achieves economic efficiency is to equate price with marginal cost. Since public transport demand is derived from some other demand, the user cost as well as the producer cost are considered in its pricing. The optimal price is derived from a derivative of the total social cost with respect to demand. In case of the bus, if there is enough capacity for demand increase, the optimal price is determined by the marginal producer cost resulting from bus sped decrease and by the marginal user cost resulting from journey time increase. Both are caused by boarding and fare collecting time of an additional passenger. Because of the budget constraints, the marginal cost pricing cannot be applied in practice. Then price discrimination as the second-best pricing is introduced. The Ramsey pricing, to charge different prices for different demand elasticities, and nonuniform prices such as travelcards can be applied. However, there is practical difficulty in implementing these prices because of great informational requirements, the costs of administration and the ease to users.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.207-209
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• 1996

The software of the midclass commuter flight simulation is running on multiprocessor/multitasking environments The software is consist of tasks which are periodically alive at a given interval. Each task communicates via shared memory. The data shared by tasks is divided by several block. Only one task, called producer, can produce data for a data block but several tasks, called consumers, can read data from the data block. Double buffer and conditional flag are used to implement a mutual exclusion which prevents the producer and consumers from accessing the same data block simultaneously.