• Journal of Korean Society for Quality Management
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• v.31 no.1
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• pp.132-141
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• 2003

As the technology has improved and demands of customers have varied, a lot of products are getting diverse and intricate. Consequently, the enterprise that produce products have to simultaneously consider the various variables for the very products. There are some scheme, such as Multivariate control chart and Demerit control chart, designed to simultaneously monitor the variables in the process. In this paper, we present an effective method for process control using the Demerit-CUSUM control chart in the process where nonconforming units or nonconformities are occured by various types. In addition, we show interpretation method for abnormal signal in order to quickly detect the assignable causes as Demerit-CUSUM control chart signals abnormality. we compare performance of Demerit control chart and Demerit-CUSUM control chart using example again used in the existing studies, and present result of performance accoriding to changing sample size and parameter.

• Journal of Global Scholars of Marketing Science
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• v.18 no.2
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• pp.47-64
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• 2008

It is well known that consumer's quality perception is strongly affected by price. Higher priced products tend to be perceived to have better quality than lower priced products although the objective product quality is the same. However, it is less known the process through which quality perception is affected by price cues. The existing literature suggests three potential hypotheses (i.e., the selectiveprocessing hypothesis, the selective interpretation hypothesis, and the representativeness heuristic hypothesis) that explain the underlying processes of the price-induced quality perception. The current research tests among the three competing hypotheses and also examines the role of consumer knowledge as a moderating factor. An experiment was conducted to test the moderating role of the knowledge in the price-quality relationship and to investigate the underlying process. The results indicate that theinfluence of price on perceived quality differs between novices and experts. Expert consumers' quality perception is not significantly influenced by price and this finding is consistent with the extant literature. On the other hand, novice consumers' quality perception is affected by price and the tests on the underlying process support for the representativeness heuristic hypothesis. Novice consumers assess that a high-priced brand should have good product quality due to the belief that high (low) price brands represent better (worse) brand quality and such a representativeness heuristic occurs without involving selective attention or selective interpretation price-consistent information.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.45
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• pp.265-277
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• 1998

The control chart has been used widely and importantly as a tool for statistical process control(SPC). Most companies are concerned with improving the quality and the productivity as well as reducing the cost, especially in today's highly competitive environment. Though SPC is known as a technique for consistent quality, it is not used properly due to lack of knowledge about it. It is required to develop a support system for control chart selection and interpretation that can be utilized by non-specialist without hard training or experiences. The support system was developed by applying the expert system tool to popular control charts. Though some researches on this area has been performed, the implemented results expose many problems in field applications due to the unsatisfactory explanation of the selected control chart and limited knowledge base for resolving the problems. This thesis presented an expert system for control chart as solution for these problems. The expert system for the control chart selection and interpretation is developed by using Turbo C and EXSYS which is an expert system development tool.

• The Journal of Bigdata
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• v.4 no.2
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• pp.61-71
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• 2019

Chemical Mechanical Planarization (CMP) process that planarizes semiconductor wafer's surface by polishing is difficult to manage reliably since it is under various chemicals and physical machinery. In CMP process, Material Removal Rate (MRR) is often used for a quality indicator, and it is important to predict MRR in managing CMP process stably. In this study, we introduce prediction models using machine learning techniques of analyzing time-series sensor data collected in CMP process, and the classification models that are used to interpret process quality conditions. In addition, we find meaningful variables affecting process quality and explain process variables' conditions to keep process quality high by analyzing classification result.

• Korean Management Science Review
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• v.27 no.3
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• pp.99-115
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• 2010

We classified quality management practices of manufacturing companies into 'Infra' factor and 'Process' factor which were introduced based on existing literatures and previous studies related to quality management. It was our first objective to confirm its conformance in Korean manufacturing industry, and to examine the two factors effect positively on production performance. Moreover, we tried to examine whether JIT and workforce management have an moderate effect on 'Infra and Process factors-performance' relationship, using moderate regression. As the result of empirical study on nationwide manufacturing companies, we had the results that the classification between Infra factor and Process factor in quality management practices was valid in Korean manufacturing companies, and that the two factors gave performances positive effect. Moreover, our secondary analysis showed that JIT had an positive moderate effect on the Infra factor while workforce management on the Process factor. With these results, we have an interpretation that manufacturing companies which aim to enhance short term performances have to concentrate their effort and investment on Process factor and, on the other hand, ones which aims to improve long term performances on Infra factor.

• The Korean Journal of Nuclear Medicine
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• v.38 no.1
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• pp.1-20
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• 2004

Bone scan is one of the most frequently peformed studios in nuclear medicine. In bone scan, the amount of radiolsotope taken up by lesion depends primarily on the local rate of bone turnover rather than on the bone mass. Bone scan is extremely sensitive for defecting bony abnormalities. However, abnormalities that appear on bone scan may not always represent disease. The normal scan appearances may be affected not only by skeletal physiology and anatomy but also by a variety of technical factors which can influence image quality. Many normal variants and artifacts may appear on bone scan. They could simulate a pathologic process and could mislead into the wrong diagnostic interpretation. Therefore, their recognition is necessary to avoid misdiagnosis. A nuclear medicine physician should be aware of variable appearance of the normal variants and artifacts on bone scan. In this article, a variety of normal variants and artifacts mimicking real pathologic lesion in bone scan interpretation are discussed and illustrated.

• Journal of Korean Society for Quality Management
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• v.21 no.2
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• pp.242-253
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• 1993

The interpretation of the reaction mechanism is significant to produce the high quality welds and understand the welding processes. This investigation is important for the design of welding consumables and the selection of welding process parameters to develop the high quality welds. The objective of this study is to investigate the effect of electrochemical reactions on the transfer of alloy elements between slag and weld metal during submerged arc welding During submerged arc welding weld metal composition is shown to be controlled by two reaction mechanisms in four reaction zones. The responsible reaction mechanisms are thermochemical and electrochemical reactions. The possible reaction sites are the melted electrode tip, the detached droplet, the hot weld pool immediately below the moving electrode, and the cooling and solidifying weld pool behind the moving electrode. The possible reactions in submerged arc welding at different zones of the process is schematically shown in Figure 1.

• Journal of the Korean Society of Food Culture
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• v.14 no.2
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• pp.167-175
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• 1999

This study examines the effects of the Korean horticultural foods which are, by traditional wisdom, supposed to contain anti-aging substance. All twenty three kinds of plants are chosen as a sample for the experiment in which the content of three main anti-aging nutrients, -carotene, Vitamin C, and Vitamin E are respectively measured by Nilis, Colorimetric, and AOAC method. The result shows: among the samples, top six plants that contain the most -carotene content are high quality tea(Camellia sinensis), thistle(Cirsium japonicum Var.), Angelica keiskei, mulberry leaves(Morus alba l.), field horsetail(Equisetum arvensa), and carrot(Daucus carota), in order; top four for a Vitamin C contents are low quality tea, mulberry leaves, pine leaves(Pinus densiflora), and high quality tea, in order; top four for a Vitamin E contents are persimmon leaves(Diospyros mongolicum) tea, high quality tea, low quality tea, and pine leaves, in order. Drying or boiling process increases the content of -carotene and Vitamin E in high quality tea, dropwort(Oenanthe javanica), field horsetail, and wild aster(Ligularia stenocephala Marsumum et Koldzumi), while, in case of mulberry leaves, drying process lowers them. Vitamin C content strikingly decreases in heating and drying process.

• Journal of Korean Society for Quality Management
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• v.28 no.2
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• pp.147-160
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• 2000

An objective of the 100PPM Quality Renovation, which is settled as the Korea quality renovation activity as well as the form of customer-oriented management renovation climate, is strengthening an enterprise competitiveness by worldwide quality insurance. In long-term, the 21 century's quality problem would not be effective without synthetic approach from the view point of management strategy. Another method to obtain the quality ascendancy could be an strategic application of, manufacturing function. In this research, the progressive direction for an effective approach to the 100PPM Quality Renovation is examined through the interpretation of process capability index. Finally, the deployment direction of quality renovation activity is searched.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.22-28
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• 2013

Robotic GMA (Gas Metal Arc) welding process is one of widely acceptable metal joining process. The heat and mass inputs are coupled and transferred by the weld arc to the molten weld pool and by the molten metal that is being transferred to the weld pool. The amount and distribution of the input energy are basically controlled by the obvious and careful choices of welding process parameters in order to accomplish the optimal bead geometry and the desired quality of the weldment. To make effective use of automated and robotic GMA welding, it is imperative to predict online faults for bead geometry and welding quality with respect to welding parameters, applicable to all welding positions and covering a wide range of material thickness. MD (Mahalanobis Distance) technique was employed for investigating and modeling the GMA welding process and significance test techniques were applied for the interpretation of the experimental data. To successfully accomplish this objective, two sets of experiment were performed with different welding parameters; the welded samples from SM 490A steel flats. First, a set of weldments without any faults were generated in a number of repeated sessions in order to be used as references. The experimental results of current and voltage waveforms were used to predict the magnitude of bead geometry and welding quality, and to establish the relationships between weld process parameters and online welding faults. Statistical models developed from experimental results which can be used to quantify the welding quality with respect to process parameters in order to achieve the desired bead geometry based on weld quality criteria.