• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.745-750
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• 2014

The chatter vibration in the machining process plays bad role in machining quality such as high roughness as well as tool life and machine failure. And the grinding process under this risk in the fully automated factory is exposed to the unexpected mass machining quality problem. Studying the vibration signal of the hub bearing grinding process, the reason of chatter vibration was explained with the specific machining pattern of chatter. And this study suggests the chatter detecting method in the production line, which is monitoring the peak acceleration level around the natural frequencies of the specimen, and calculating kurtosis value by assuming the chatter is related to the resonance of the specimen. The suggested method was applied to the vehicle hub bearing grinding process and proved good to detecting the chatter induced machining quality problem.

• Journal of Communications and Networks
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• v.12 no.1
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• pp.30-42
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• 2010

In this work we consider the problem of downlink resource allocation for proportional fairness of long term received rates of data users and quality of service for real time sessions in an OFDMA-based wireless system. The base station allocates available power and subchannels to individual users based on long term average received rates, quality of service (QoS) based rate constraints and channel conditions. We formulate and solve a joint bandwidth and power optimization problem, solving which provides a performance improvement with respect to existing resource allocation algorithms. We propose schemes for flat as well as frequency selective fading cases. Numerical evaluation results show that the proposed method provides better QoS to voice and video sessions while providing more and fair rates to data users in comparison with existing schemes.

• Journal of Korean Society for Quality Management
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• v.17 no.2
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• pp.47-54
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• 1989

This study is concerned with the reduction of fraction defective for quality improvement model in manufacturing system. For the methodology, a heuristic method for the selection of alternatives of process improvement is introduced for quality improvement and cost problem subject to cost constraints. This study suggests a model for selecting fraction defective reduction alternatives in multi-stage manufacturing system and a numerical example is presented.

• Journal of Korean Society for Quality Management
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• v.26 no.3
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• pp.46-59
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• 1998

The problem of selecting optimal target values for the mean of the quality characteristic of interest for a production process in which an item is sold in one of two market with different profit / cost structures or reworked. Two profit models are constructed which involve four profit / cost components: profit, production, inspection, and rework costs. Assumed that the quality characteristic of interest is normally distributed, methods of finding the most profitable process mean are presented and a numerical example is given.

• International Journal of Quality Innovation
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• v.10 no.2
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• pp.19-27
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• 2009

This paper considers the short term fleet scheduling problem as described by Keskinocak and Tayur (1998). Fleet scheduling may directly affect the service quality of fractional jet aircraft business. The contributions of this paper are two: (i) we show how their model is easily implemented in a standard modeling language, LINGO, and (ii) an alternate formulation is given which is expected to perform better on large, difficult problems.

• Journal of the Korean Data and Information Science Society
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• v.16 no.4
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• pp.823-833
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• 2005

This paper deals the TFT-LCD process and quality, process control problems of the process. For improvement of the process quality and yield, we apply a data mining technique to the LCD industry. And some unique quality features of the LCD process are also described. We describe some preceding researches first and relate to the TFT-LCD process and the problems of data mining in the process. Also we tried to observe the problems which need to solve first and the features from description below hazard must be considered a quality mining in LCD industry.

• Journal of Korean Society for Quality Management
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• v.27 no.2
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• pp.20-46
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• 1999

Many researches have concluded that product advantage or superiority is the most important factor for the commercial success of new products. However, the specific dimensions of product advantage have not been studied as yet. Based on a survey of newly introduced products in recent years, we suggest the eight dimensions of quality of new product: function, time, limitation, usability, problem prevention, economy, maintainability, nativeness. The dimensions and their constituents are explained with examples.

• Journal of Korean Society for Quality Management
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• v.38 no.1
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• pp.108-114
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• 2010

In this research, we study to find core factor of the perceived quality of internal quality and external quality factors on agriculture products and food industry. By empirical research, we prove that the perceived quality effects to the customer attitude on agricultural products and food Industry. The results of this research can contribute in working-level practical use about quality problem in agriculture products and food industry. The latest interest of customer attitude on agricultural products and food Industry is being rosed.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.1
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• pp.69-74
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• 2004

A sequencing problem is to find an ordered sequence of some entities which maximizes (or minimize) the domain specific objective function. As some typical examples of sequencing problems, there are traveling salesman problem, job shop scheduling, flow shop scheduling, and so on. This paper introduces a new type of sequencing problems, named a sequencing problem with fuzzy preference relation, where a fuzzy preference relation is provided for the evaluation of the quality of sequences. It presents how such a problem can be formulated in terms of objective function. It also proposes a genetic algorithm applicable to such a sequencing problem.

• Journal of the Korean Home Economics Association
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• v.39 no.5
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• pp.15-26
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• 2001

The purpose of this study is to examine specific consumer problems in internet commerce and analyze them in the age of information. The way of sorting consumer problems in internet commerce from this study. For this empirical analysis, the data was collected 319 consumers by internet on-line survey from Feb. 13 to Feb. 20, 2000. The methods for study was frequency, percentage, mean, correlation, multiple regression using SAS PC program. The major findings of this study were as follows: 1. The level of consumer problem experiences in internet commerce was examined. The problems of privacy was the most problem and the problem of price was the second. Then delivery, advertisement, information was next, and the problem of quality, and A/S, change, cancel was the next consumer problem. 2. Among factors influence on experience consumer problem in internet commerce, the amount of usable money, information search were significant.