• 가족자원경영과 정책
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• 제8권3호
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• pp.33-46
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• 2004

This study examined the effects of consumers' perceptions and expectations about refund on consumers' behavior to refund and its outcome. Major results of this study could be summarized as follows. First, consumers' perceptions and expectations about refund were higher in the case of defective products. However, consumers' behavior to refund were generally passive resulting in the low chance of refund. When there was no defects in product, consumers perceptions and expectations for refund were generally lower resulting in passive and the low chance of refund. Second, when there was defects in product, both consumers' perceptions and expectation tot refund influenced their active behaviors for refund, but not in the successful outcome. In contrast, when there was no defect, those two variables impacted on the behaviors for refund positively In addition, the more active those behaviors requesting for refunds were, the more successful outcome in refund request.

• Asian Journal of Business Environment
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• 제5권2호
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• pp.23-29
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• 2015

Purpose - This theoretical study develops practical recommendations for implementing a quality management system (QMS) in Kazakh organizations to ensure the effectiveness and safety of products and services. We discuss the improvement of Kazakhstan's quality standards based on the requirements of ISO 9000. Research design, data, and methodology - We provide methods for improving the quality standards system, ranging from research and development to the sale of products. We also propose to establish a special quality systems award to motivate enterprises toward product quality improvement. The study's methodological basis included Kazakhstan's legislative and regulatory Acts, and international and national standards defining QMS requirements for scientists worldwide to develop and implement a QMS for enterprises. Results - Aligning the QMS reduces Kazakh companies' costs for the detection and correction of defects, and the external and internal loss caused by the defects. Effective QMS also reduces management costs. Conclusion - This article can help increase the transparency of organizations for their leaders and (if necessary) the external environment, and improve the accuracy, quality, and timeliness of decision-making.

• 한국의류학회지
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• 제32권9호
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• pp.1356-1365
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• 2008

As Korean retailers are expanding their return policies, customer abuse and fraud behaviors are increasing. This study attempts to understand customers' unethical return behaviors in the Korean retailing. As an exploratory approach, the study identifies behavioral patterns of unethical returns from retail employees' perspectives. A total of 168 cases collected from 112 individual interviews with retail employees are qualitatively analyzed. Unethical return behaviors are categorized into five groups: lenting/deshopping, product defects with customer faults, unreasonable compensation demands, selfish behaviors, and problem behaviors in the service encounter. The study indicates that a variety of unethical return behaviors are observed despite a short history of return policy in Korea, and renting/deshopping and product defects with customer faults are the most prevalent return abuse behaviors.

• Smart Structures and Systems
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• 제29권6호
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• pp.767-775
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• 2022

Metal additive manufacturing (AM), also known as metal three-dimensional (3D) printing, produces 3D metal products by repeatedly adding and solidifying metal materials layer by layer. During the metal AM process, products experience repeated local melting and cooling using a laser or electron beam, resulting in product defects, such as warpage, cracks, and internal pores. Such defects adversely affect the final product. This paper proposes the in situ monitoring-based warpage prediction of metal AM products with experimental feature extraction. The temperature profile of the metal AM substrate during the process was experimentally collected. Time-domain features were extracted from the temperature profile, and their relationships to the warpage mechanism were investigated. The standard deviation showed a significant linear correlation with warpage. The findings from this study are expected to contribute to optimizing process parameters for metal AM warpage reduction.

• Journal of the Korean Data and Information Science Society
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• 제15권2호
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• pp.387-394
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• 2004

Zero-Inflated Poisson distribution is Poisson distribution with excess zeros. Recently defects of product hardley happen in the manufacturing process. In this case it is desirable to apply to the Zero-Inflated Poisson distribution rather than Poisson. Our target of this paper is to study the tests for changes of rate of defects after the unknown change-point. We are going to compare the powers of the two proposed tests with likelihood tests by the simulations.

• 품질경영학회지
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• 제27권1호
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• pp.223-231
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• 1999

The concept of six sigma was introduced at and popularized by Motorola in its quest to reduce defects of manufactured electronics products. When used as a metric, six sigma technically means having no more than 3.4 defects per million opportunities in any process, product, or service. More important than the technical definition is the concept of six sigma as a disciplined, quantitative approach for improvement of defined metrics in manufacturing, service, or financial processes. This approach derives the overall process of selecting the right projects based on their potential to improve performance metrics and selecting and training the right people to get the business results.

• 산업공학
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• 제15권2호
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• pp.107-113
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• 2002

Recent reports studied that injuries or deaths frequently occurred in consumer product accidents by product defects. Broadly speaking, product liability is liability which is imposed upon a manufacturer or other seller for personal injury, death, property damage and/or commercial loss arising with respect to a product or service provided by it. In this study, we want to search a method of prevention against appling PL laws. The way was researching on the level of appreciation of PL law, warning messages's means and design criteria for seller or consumer of child toys. As a result, most people didn't understand PL laws. Although they read them before purchasing child toy, many consumers didn't differentiate means of "Notice", "Warning", and "Danger" in warning messages. In addition, they considered important factors in warning messages as notice warning, safety mark(UL, etc), age recommendation and color in order. This study will be effective to search a method of prevention against PL laws.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.371-374
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• 2003

The bending process for the "ㄱ" section product can be developed by the hot metal extrusion machine with the two punches moving in the different velocity. The bending phenomenon can be controlled by difference of velocity at the die exit section by the different velocity of billets through the two-hole container. The results of the experiment show that "ㄱ" section product can be bended by the extrusion process and that the curvature of the product can be controlled by the velocity of punch and that the defects such as the distortion of section and the thickness change of the product and the folding and wrinkling of the product did not happen after the bending processing by the extrusion bending machine.

• 품질경영학회지
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• 제51권1호
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• pp.55-65
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• 2023

Purpose: The purpose of this study is to propose an optimization process to improve product yield in the process using process data. Recently, research for low-cost and high-efficiency production in the manufacturing process using machine learning or deep learning has continued. Therefore, this study derives major variables that affect product defects in the manufacturing process using eXplainable Artificial Intelligence(XAI) method. After that, the optimal range of the variables is presented to propose a methodology for improving product yield. Methods: This study is conducted using the injection molding machine AI dataset released on the Korea AI Manufacturing Platform(KAMP) organized by KAIST. Using the XAI-based SHAP method, major variables affecting product defects are extracted from each process data. XGBoost and LightGBM were used as learning algorithms, 5-6 variables are extracted as the main process variables for the injection process. Subsequently, the optimal control range of each process variable is presented using the ICE method. Finally, the product yield improvement methodology of this study is proposed through a validation process using Test Data. Results: The results of this study are as follows. In the injection process data, it was confirmed that XGBoost had an improvement defect rate of 0.21% and LightGBM had an improvement defect rate of 0.29%, which were improved by 0.79%p and 0.71%p, respectively, compared to the existing defect rate of 1.00%. Conclusion: This study is a case study. A research methodology was proposed in the injection process, and it was confirmed that the product yield was improved through verification.

• 제어로봇시스템학회논문지
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• 제6권2호
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• pp.207-216
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• 2000

This paper introduces an effective system design method to develop a customer oriented product using a design optimization process and to select a set of critical design paramenters,. The process results in the development of a successful product satisfying customer needs and reducing development risk. The proposed scheme adopted a five step QFD(Quality Function Deployment) in order to extract design parameters from customer needs and evaluated their priority using risk factors for extracted design parameters. In this process we determine critical design parameters and allocate them to subsystem designers. Subsequently design engineers develop and test the product based on these parameters. These design parameters capture the characteristics of customer needs in terms of performance cost and schedule in the process of QFD, The subsequent risk management task ensures the minimum risk approach in the presence of design parameter uncertainty. An application of this approach was demonstrated in the development of weld quality monitoring system. Dominant design parameters affect linearity characteristics of weld defect feature vectors. Therefore it simplifies the algorithm for adopting pattern classification of feature vectors and improves the accuracy of recognition rate of weld defect and the real time response of the defect detection in the performance. Additionally the development cost decreases by using DSP board for low speed because of reducing CPU's load adopting algorithm in classifying weld defects. It also reduces the cost by using the single sensor to measure weld defects. Furthermore the synergy effect derived from the critical design parameters improves the detection rate of weld defects by 15% when compared with the implementation using the non-critical design parameters. It also result in 30% saving in development cost./ The overall results are close to 95% customer level showing the effectiveness of the proposed development approach.