• 소성∙가공
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• 제33권4호
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• pp.277-284
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• 2024

Interest in remanufacturing of part has significantly increased to reduce used material and energy together. The directed energy deposition (DED) process has widely applied to remanufacturing of the part. An excessive residual stress takes place in the vicinity of the deposited region by the DED process due to rapid heating and rapid cooling (RHRC) phenomenon. The excessive residual stress decreases the reliability of the remanufactured part. Therefore, thermo-mechanical analysis for the remanufacturing of the part is needed to investigate heat transfer and residual stress characteristics in the vicinity of the deposited region. The thermo-mechanical analysis of a large volume deposition is significantly difficult to perform due to the requirement of a long computation time and a large computer memory. The goal of this paper is to investigate thermo-mechanical characteristics for remanufacturing of the ATC part using a DED process. The methodology of the thermo-mechanical analysis for a large volume deposition is proposed. From the results of analysis, heat transfer and residual stress characteristics during deposition and cooling stages are investigated. In addition, the proper deposition strategy from the viewpoint of the residual stress is discussed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.387-388
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• 2012

• 한국안전학회지
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• 제33권2호
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• pp.112-123
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• 2018

In this paper, we focused on the safety of workers in a remanufacturing process where a risk analysis is not carried out and suggested a criteria for evaluating injury risk. We analyzed a disassembly and a reassembly, which are important for the remanufacturing process. The disassembly includes the disassembly of product and the disassembly process of part and the reassembly includes only reassembly of part. First of all, we analyzed the remanufacturing process and a type of injury. Then, we reviewed the standards and determined the criteria for a severity and an occurrence. We set a bigger weight for the severity to allow the greater impact. And the injury risk score was defined as a sum of the weighted severity and the weighted occurrence. We conducted a qualitative analysis of the experience of field workers based on the criteria we set up. Questionnaires for the evaluation were formulated through interviews with experts.

• Industrial Engineering and Management Systems
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• 제13권2호
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• pp.231-249
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• 2014

This paper discusses a green supply chain with a manufacturer and a collection trader, and it proposes an optimal production planning for remanufacturing of parts in used products with quality classification errors made by the collection trader. When a manufacturer accepts an order for parts from a retailer and procures used products from a collection trader, the collection trader might have some quality classification errors due to the lack of equipment or expert knowledge regarding quality classification. After procurement of used products, the manufacturer inspects if there are any classification errors. If errors are detected, the manufacturer reclassifies the misclassified (overestimated) used products at a cost. Accordingly, the manufacturer decides to remanufacture from the higher-quality used products based on a remanufacturing ratio or produce parts from new materials. This paper develops a mathematical model to find how quality classification errors affect the optimal decisions for a lower limit of procurement quality of used products and a remanufacturing ratio under the lower limit and the expected profit of the manufacturer. Numerical analysis investigates how quality of used products, the reclassification cost and the remanufacturing cost of used products affect the optimal production planning and the expected profit of a manufacturer.

• 소성∙가공
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• 제30권3호
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• pp.109-118
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• 2021

Recently, there has been an increased interest in the remanufacturing of mechanical parts using metal additive manufacturing processes in regards to resource recycling and carbon neutrality. DED (directed energy deposition) process can create desired metallic shapes on both even and uneven substrate via line-by-line deposition. Hence, DED process is very useful for the repair, retrofit and remanufacturing of mechanical parts with irregular damages. The objective of the current paper is to investigate the effects DED process parameters, including the effects of power and the scan speed of the laser, on deposition and residual stress characteristics for remanufacturing of mechanical parts using experiments and finite element analyses (FEAs). AISI 1045 is used as the substrate material and the feeding powder. The characteristic dimensions of the bead shape and the heat affected zone (HAZ) for different deposition conditions are obtained from the experimental results. Efficiencies of the heat flux model for different deposition conditions are estimated by the comparison of the results of FEAs with those of experiments in terms of the width and the depth of HAZ. In addition, the influence of the process parameters on residual stress distributions in the vicinity of the deposited region is investigated using the results of FEAs. Finally, a suitable deposition condition is predicted in regards to the bead formation and the residual stress.

• 한국산업융합학회 논문집
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• 제25권6_3호
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• pp.1315-1324
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• 2022

The need for remanufacturing ships and various mechanical components continues to increase along with environmental problems. Research on remanufacturing is being carried out in various fields, but research on cleaning is quite insufficient. In particular, there is no research on the cleaning-ability of diverse mechanical components. In order to increase the life cycle of mechanical components, remanufacturing must be considered from the step of design. Particularly, it is also very important to evaluate the degree of easiness in cleaning to remove various pollutants generated by long-term use quickly as well as easily. In this study, the degree of easiness in cleaning is defined as cleaning-ability. In fact, remanufacturing components can be easily done only when cleaning-ability is set high from the step of design. The purpose of this study is to evaluate the cleaning-ability of ships and various mechanical components. The details of easiness in cleaning are cleaning and drying identification, accessibility to cleaning tools, convenience in cleaning, and convenience in drying. This study presents a quantitative procedure to evaluate cleaning-ability, derived various factors influencing each of the details of easiness and their ranges, and gave scores to the factors according to their ranges. The weight was also calculated for the details of easiness in cleaning and the factors. Lastly, this researcher suggests a scoring procedure to evaluate cleaning-ability quantitatively and the total weight of cleaning-ability.

• 한국산업경영시스템학회:학술대회논문집
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• 한국산업경영시스템학회 2002년도 춘계학술대회
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• pp.319-327
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• 2002

As one of the developing countries in the world trade market, we have to apply the environmental concept at the development of a product for environmentally conscious manufacturing system(ECMS). Traditionally, Production control model has been studied based on a new product manufacturing environment. However, ECMS such as a remanufacturing system should be developed and implemented for highly competitive environment in 21C. The objective of this study was to extend the research of production control model by applying it at the remanufacturing environment of ECMS and to test the applicability of current production control model at the remanufacturing environment by the simulation experimental study.

• 한국경영과학회지
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• 제25권4호
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• pp.111-122
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• 2000

This paper considers remanufacturing planning problems under deterministic environments. As increasing the environmental pressures in manufacturing, various methods for reducing wasted or postponing the time to be waste are considered. This paper considers remanufacturing planning problems on a single facility, where the wastes(or used products) are remanufactured to satisfy the given demand on the remanufactured products. The objective is to find the optimal remanufacturing and purchasing planning of the wastes which minimize total cost subject to satisfaction all the given demand on the remanufactured products. Two problems that the amount of wastes is a given constant or a decision variable are considered, respectively. For the problems, the extreme point solutions are characterized, and dynamic programming algorithms are developed with numerical examples.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1029-1033
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• 2004

Concern over the negative environmental impacts associated with the production, use and End-of-Life(EoL) of cellular phones is particularly high due to large production volumes and characteristically short time scales of technological and stylistic obsolescence. Therefore we have to research the environment-friendly technologies and the recycling methods. This paper introduces an improvement of cellular phone remanufacturing processes and develops the Directive of DFE(Design for Environment) for the remanufacturing of a cellular phone. Then We discuss the results of the comparative evaluations.

• 대한산업공학회지
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• 제31권3호
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• pp.240-247
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• 2005

Today's hightech society requires thousands of different products which ultimately result in billions of tons of materials discarded, most of which end up in landfills. Therefore industrial circles could not help thinking about environmental problems by regulations of government or pressures of consumer. Generally, the related research subjects are classified into both of environmentally conscious manufacturing and product recovery, where product recovery aims to minimize the amount of waste sent to landfills by recovering materials and parts from old or outdated products by means of recycling and remanufacturing (including reuse of parts and products). In this research, we constructed a model for remanufacturing various goods using a single facility and developed a dynamic programing(DP) algorithm based upon the optimal solution characterization. We showed the efficiency of the developed DP algorithm with a numerical example.