• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10B
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• pp.936-944
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• 2006

In order to enhance their own customer satisfaction index that is one of the top level managerial performance indices, Internet communication service providers endeavor onto establishing a total quality management system. Specifically, it is under discussion that some critical Internet communication network quality characteristics closely related to customer satisfaction index should be controlled aiming to this managerial goal. This paper presents an application scheme of I-MR control charts for monitoring Internet communication network quality characteristics. This statistical quality control scheme generates a signal to practitioners when it detects the network quality characteristics out-of control. It is designed based on; 1) individual measurements; and 2) moving ranges between two consecutive individual measurements collected with a constant time interval. Empirical analyses are illustrated to estimate the expected quality improvement ratios that can be realized with the application scheme proposed in this paper. Assuming that the assignable causes can be revealed and eradicated, regarding two Internet communication services A, B, seven network quality characteristics for each service, eleven distinct measuring spots for each network quality characteristic, the expected quality improvement ratios are calculated with which the effect of the application scheme is evaluated. Results show the ranges of the expected quality improvement ratios; 1) Service A, (1) mean (0.31%-11.44%), (2) standard deviation (9.82%-71.10%): 2) Service B, (1) mean (0.29%-17.64%), (2) standard deviation (8.05%-60.59%). Hence, It is anticipated that the I-MR control charts based application scheme can be effective not only to improving the mean and dispersion of the network quality characteristics concerned but also to maintaining the network quality characteristics in-control consequently.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.283-290
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• 2020

Porous asphalt pavement is used widely in advanced countries to reduce traffic accidents and noise. On the other hand, it is not applied widely in Korea due to concerns about its durability. This study aims to find a statistical method to improve the durability of porous asphalt pavement. A Cantabro test was selected to test the durability. The Cantabro test was performed on an asphalt mixture made of a binder and aggregate. This test was repeated three times for each of the four groups to obtain the Cantabro loss rate. The average values of each of the four groups satisfied all the reference values. In addition, through an analysis of variance (ANOVA), it was possible to quantitatively classify test groups with differences in durability, thereby finding problems and improving the durability. Furthermore, the Pay Factor method can lead to voluntary improvements in quality, and the Pay factor can be calculated through statistical analysis of limited data. Through the Pay factor, it is possible to induce definite quality improvement of the contractor and continuously improve the durability of the porous asphalt mixture by evaluating the adequacy of the quality standard.

• Journal of Korean Society for Quality Management
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• v.33 no.1
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• pp.22-31
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• 2005

With the common objective to improve process productivity and product quality, statistical process control (SPC) and engineering process control (EPC) have been widely used in the discrete-parts industry and the process industry, respectively. The major focus of SPC is on process monitoring, while that of EPC is on process adjustment. The emergence of the hybrid industry necessitates a synergistic combination of the two methods for an effective process control. This paper investigates the existing studies on SPC, EPC, and the integration of the two methods. This paper also presents future research issues in this field.

• Journal of Information Technology Application
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• v.3 no.4
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• pp.119-134
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• 2001

Improving software product quality is a key to increasing user satisfaction and to achieving competitive edge. There are two approaches to assure high software product quality; development process-oriented and product-oriented. There have been many efforts for improving software quality through process certification, for example, CMM, ISO 9000 family, ISO/IEC 12207, SPICE and Bootstrap. However, a good process alone cannot guarantee good product quality. A need for the evaluation of software product quality by an independent third party is growing rapidly for several reasons. We are concerned with an application of Statistical Quality Control (SQC) to the evaluation of software product quality to obtain the efficiency of evaluation processes and the objectivity of evaluation results. Methods for selecting test cases using a random sampling approach have been discussed and methods for selecting acceptance criteria with respect to software product quality have also been suggested.

• Journal of Korean Library and Information Science Society
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• v.41 no.1
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• pp.255-272
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• 2010

This paper aims to describe the measurement and improvement of academic library service quality by ISA (Importance-Satisfaction Analysis). This research established service quality model on based LibQUAL+(R). It consisted of 18 items that formed three dimensions, affect of service quality, information control quality, and library as place quality. To execute this research, the service quality according the users' importance and satisfaction of library service is measured through Gaps model and ISA. The data for this case study was collected through the survey conducted the users of the H University library. By applying SPSS 17.0 and Excel 2007, the final 113 surveys were used for analysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.238-247
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• 2006

The purpose of this study was to evaluate school dieticians' performance of nutritional quality control, and further to establish effective and objective standards of nutritional quality control. Data for this study came from 200 school dieticians' responses in the Chungbuk area. The total quality management (TQM)-based questionnaire was structured. The questionnaire consisted of the following four fields (1) performance of nutritional quality control, (2) performance of stepwise food production to maximize nutrient preservation rate, (3) management of documents and records related to nutritional quality control, and (4) other relating matters. The items of the questionnaire were measured on a five-point Likert scale which ranged from 'strongly agree' to 'strongly disagree'. First, the analysis indicated that school dieticians performed 'least' on human resource management', 'mediocre' on nutritional quality control, and best on 'leadership'. Second, the analysis on performance of stepwise food production to maximize nutrient preservation rate showed that dieticians considerably endeavored to maximize nutrients of cooked food, but it was found out that the most of nutrient destruction can be caused by heating during cooking. Third, the result showed that the systematic use of documents and records for nutritional quality control was not sufficiently accomplished, especially in the production phase of food. In addition, the measure by the Pearson correlation coefficient indicated that there was a significant relationship between performance of nutritional quality control and performance of stepwise food production to maximize nutrient preservation rate, and between performance of nutritional quality control and management of documents and records related to nutritional quality control. Finally, the findings of this study suggest that more effort should be exerted to carefully establish TQM-based standards for the improvement of nutritionary quality.

• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.353-363
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• 2020

Purpose: The purpose of this study is to verify the effects of assessment and compensation system, information technology, knowledge quality, and knowledge management activities on the earthquake disaster management job performance. Method: Questionnaire survey was performed for the fire officials, and the multi-regression analysis for surveyed data was statistically performed by using SPSS 25.0 program. Result: Information technology, knowledge quality and knowledge management activities among the factors of the knowledge management system related to earthquake disasters have had significant positive effects on the earthquake disaster management job performance, but assessment and compensation system are found to have no significant effects on the earthquake disaster management job performance. Conclusion: It was confirmed that the higher the level of information technology, knowledge quality and knowledge management activities related to earthquake disasters, the higher the disaster management job performance.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.500-504
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• 2004

본 논문에서는 한 중소기업을 상대로 진행된 게이트 도장 품질 개선을 위한 6시그마 프로젝트 과정을 소개한다. 프로젝트는 6시그마 개선활동의 로드맵인 DMAIC 절차를 따라 진행하였다. 먼저 Define 단계에서는 고객요구사항 파악을 위해 VOC 기법을 활용하여 CTQ를 선정하였다. Measure 단계에서는 프로세스 맵, 특성요인도, XY 매트릭스, FMEA등을 이용하여 주요 인자들을 규명하였다. Analyze 단계에서는 상관분석, ANOVA, 그래프 분석 등 각종 통계적 기법을 활용해 핵심입력변수인 'Vital Few's'를 규명한 후, Improve 단계에서 DOE를 통한 최적조건을 도출하였다. 또한 Control 단계에서는 최적조건을 유지하기 위한 관리계획 및 실수방지, 표준화 기법을 도입하였다. 이러한 개선 활동을 통해 개선 전 2.957 시그마 수준의 품질을 3.66 시그마 수준까지 높일 수 있었으며, 6천 3백만원의 비용절감을 할 수 있었다. 또한 본 논문에서는 중소기업에서의 프로젝트 진행의 문제점을 제시하였고, 그 해결방안에 대해서도 논하고자 한다.

• Annual Conference of KIPS
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• 2000.10a
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• pp.555-558
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• 2000

소프트웨어 프로세스 능력 수준에 영향을 미치는 요인을 찾아내어, 강점은 격려하고 약점을 개선하는 프로세스 개선활동은 기업의 경쟁력 향상을 위하여 매우 중요한 일이다. 본 연구에서는 이러한 요인을 찾아내기 위하여 SPICE(ISO/IEC 15504) 프로젝트에서 국제적으로 실시된 소프트웨어 심사 결과를 이용하였다. 분석 요인으로 IT부서 사원수, ISO 9001 인증여부, 안정성, 경제적 손실도, 보안성, 환경 영향도를 사용하였으며, 본 자료가 범주형이므로 분석 방법으로 통계적인 방법론인 "수량화방법 II"를 이용하였다. 수량화방법 II에서는 요인의 중요도를 나타내는 지표로 범위와 편상관을 사용한다. "범위"를 지표로 할 경우, 보안성이 능력수준과 가장 높은 관련이 있는 것으로 나타났으며, "편상관"을 지표로 할 경우, ISO 9001 인증이 가장 관련이 높은 것으로 나타났다. 이는 보안성이 높게 요구되는 회사의 경우, 품질시스템이 잘 갖춰져 있고, ISO 9001 인증을 받는 둥의 품질관리를 하여 프로세스 능력수준 또한 높게 나왔다고 추론할 수 있다.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.37-41
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• 2016

Purpose The importance of quality control by the error to a minimum, which for the purpose of enhancing the reliability of the examination is not be emphasized excess. Currently, most nuclear medicine laboratory are conducting the internal and external quality control, and they are applying the Levey-Jennings or Westgard Multi-Rules by using the commercialized quality control materials. The reliability of the nuclear medicine blood test which affects the diagnosis of patients and the treatment policy is being secured through this quality control activity. Therefore, researchers will evaluate the utility of the statistic quality control using the population distribution of the nuclear medicine blood test conducted targeting the checkup examinees by the additional technique of the reliability improvement. Materials and Methods A statistic analysis was performed about 12 items of the nuclear medicine blood test targeting 41,341 peoples who used the health screening and promotion center in Asan Medical Center from January, 2014 to December, 2014. The results of 12 items of the nuclear medicine blood test was divided into the monthly percentage of three groups: within reference values, over reference, and under reference to analyze the average value of the population distribution, standard deviation, and standard deviation index (SDI). Results The standard deviation of the population distribution mostly showed a result within ${\pm}2SD$ in all groups. However, When the standard deviation of the population distribution represented a result over ${\pm}2SD$, it was confirmed SDI was showing a result of SDI > -2 or SDI > 2. As a result of analyzing the population distribution of 12 items(AFP, CEA, CA19-9, CA125, PSA, TSH, FT4, Anti-Tg-Ab, Anti-TPO-Ab, Calcitonin, 25-OH-VitD3, Insulin) of the nuclear medicine blood part basic test, when SDI of the monthly percentage which deviated from the reference values was over ${\pm}2.0$, CA19-9 September was 2.2, Anti-Tg-Ab may was 2.2, Insulin January was 2.3, Insulin March was 2.4. It was confirmed these cases were attributed to the abnormality of the test reagent (maximum combination rate of isotope reagent declined) and the decline of the test response time. Conclusion The population distribution includes the entire attribute which becomes the study object. It is expected the statistic quality management using the population distribution which was conducted targeting the checkup examinees by dividing into three groups: within reference values, over reference, and under reference by means of this characteristics will be able to play a role of complementing the internal quality control program which is being carried out in the laboratory.