• Journal of Korea Society of Digital Industry and Information Management
• /
• v.9 no.3
• /
• pp.195-209
• /
• 2013

Purpose of this study is to empirically consider relation between QM activity factor and management result. For this, following 6 major variables of QM activity were established as independent variable; CEO's leadership, communication, process control, standardization, full participation and education/training while satisfaction of members and improvement of quality were established as dependent variable. And, a model was set up and hypothesis verification was conducted on the basis of data collected through questionnaires. The results are summarized as follows; First, QM factors which influenced satisfaction of members in management result were CEO's leadership, communication, process control, full participation and education/training but 'standardization' factor was not statistically significant. Second, QM factors which influenced improvement of quality in management result were CEO's leadership, communication, standardization, full participation and education/training but 'process control' factor was not statistically significant. Third, among main factors of QM activity, the factor which preferentially influenced satisfaction of members was 'full participation' factor while the factor which preferentially influenced improvement of quality was 'standardization' factor. According to such results, it is required to seek a statistical method regarding QM activity with focus on the factor of 'full participation' and 'standardization' among other things for the purpose of satisfaction of members as well as improvement of quality. It is believed that implication of this study can be useful information to realize management result considering main factors of QM activity and that it also can be basic reference data to seek a statistical method for satisfaction of members and improvement of quality by grasping core factors having influence over QM activity.

• Korean Journal of Health Education and Promotion
• /
• v.20 no.4
• /
• pp.67-78
• /
• 2003

This investigation was performed to summarize a few prominent features of smoking prevention program studies and to evaluate the quality of smoking prevention program studies using the Quality of Study Rating Form (QSRF). 24 school-based smoking prevention programs were subjected to an evaluation of study quality using QSRF. Study quality was 57.29 points out of 100 points on average, so it cannot be said that study quality was good. Most of the studies described the subjects and the intervention contents and intervention time. 50% stated where the intervention occurred specifically, 50% of the studies either discussed a specific theory that justified the use of one or more intervention methods, or they cited literature said to support the chosen intervention method. Only one study assigned subjects randomly to experimental groups or control groups and 50.0% of the studies showed baseline equality. There was no study where subjects were blind to being in the treatment or control group or where subjects were selected randomly by random sampling procedure. 79.2% of the studies had non-treated control groups and 20.8% of the studies had comparison groups with other treatments in the form of either other delivery methods or other contents. Sample sizes were larger than 21 in the experimental group for all studies. 75% of the studies stated face validity of outcome measure or cited from previous literature. 58.3% of the studies tested reliability and 45.8% reported the reliability measure was a figure of .70 or greater. There was no study where those rating outcomes were rated blind, because researchers generally collected data by themselves. Outcome measures were taken only after the intervention was completed and tests of statistical significance were generally referred to statistical method and p value in all studies. All studies met the criteria that follow-up was greater than 75%. The implications for the future studies were discussed.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.57 no.3
• /
• pp.121-127
• /
• 2015

The objective of this study is to suggest the water quality criteria of total nitrogen in order to efficiently manage the nutrient pollution in the stream. For this, correlations between water quality parameters were examined using the water quality data collected from the water quality monitoring network in the four rivers between 2003 and 2012. T-N showed positive correlations with T-P (0.636), COD (0.577), BOD (0.574), TOC (0.440), and SS (0.367). The statistical analysis including percentile analysis for the T-N and T-P concentrations was utilized to develop the water quality criteria of T-N. The feasibility of the suggested water quality criteria was evaluated by calculating the achievement rate to water quality target at the representative points in mid-watershed, then the draft water quality standard of T-N was suggested. The suggested water quality standard of T-N in the stream may be used to efficiently control the nutrient pollution in the public water body.

• Communications for Statistical Applications and Methods
• /
• v.19 no.5
• /
• pp.685-696
• /
• 2012

These days the interest of quality leads to the necessity of control charts for monitoring the process in various fields of practical applications. The $\overline{X}$ chart is one of the most widely used tools for quality control that also performs well under the normality of quality characteristics. However, quality characteristics tend to have nonnormal properties in real applications. Numerous recent studies have tried to find and explore the performance of $\overline{X}$ chart due to non-normality; however previous studies numerically examined the effects of non-normality and did not provide any theoretical justification. Moreover, numerical studies are restricted to specific type of distributions such as Burr or gamma distribution that are known to be flexible but can hardly replace other general distributions. In this paper, we approximate the false alarm rate(FAR) of the $\overline{X}$ chart using the Edgeworth expansion up to 1/n-order with the fourth cumulant. This allows us to examine the theoretical effects of nonnormality, as measured by the skewness and kurtosis, on $\overline{X}$ chart. In addition, we investigate the effect of skewness and kurtosis on $\overline{X}$ chart in numerical studies. We use a skewed-normal distribution with a skew parameter to comprehensively investigate the effect of skewness.

• International Journal of Korean Welding Society
• /
• v.1 no.1
• /
• pp.7-12
• /
• 2001

Real time monitoring has become critical as the use of laser welding increases. Plasma and spatter are measured and used as the signal for estimating weld quality. The estimating algorithm was made using the fuzzy pattern recognition with the area of data that is beyond the tolerance boundary. Also, an algorithm that detects the spatter and the localized defect was created in order to kd the partially produced pit and the sudden loss of weld penetration. These algorithms were used in quality monitoring of the $CO_2$ laser tailored blank weld. Statistical program that can display the laser weld quality result and the signal transition was made for the first stage of the remote control system.

• IE interfaces
• /
• v.21 no.4
• /
• pp.378-384
• /
• 2008

Small sized companies have not been successful in systematically applying statistical process control because of insufficient human resources. In this paper we present a case study of automatic checking system for a small sized company which produces various types of gears. A systematic way of automatically measuring gears is proposed and statistical analysis methods are presented. To reduce variation in the measurement data, a standard operating procedure is also proposed. This case study can be helpful to quality assurance practitioners of small sized companies who are willing to develop checking or inspection systems for their products.

• International Journal of Automotive Technology
• /
• v.6 no.6
• /
• pp.625-633
• /
• 2005

Vehicle drift was reduced using statistical six sigma tools. The study was performed through four steps: M (measure), A (analyze), I (improve), and C (control). Step M measured the main factors which were derived from a fishbone diagram. The measurement system capabilities were analyzed and improved before measurement. Step A analyzed critical problems by examining the process capability and control chart derived from the measured values. Step I analyzed the influence of the main factors on vehicle drift using DOE (design of experiment) to derive the CTQ (critical to quality). The tire conicity and toe angle difference proved to be CTQ. This information enabled the manufacturing process related with the CTQ to be improved. The respective toe angle tolerance for the adjustment process was obtained using the Monte Carlo simulation. Step C verified and controlled the improved results through hypothesis testing and Monte Carlo simulation.

• Proceedings of the Korean Reliability Society Conference
• /
• 2000.04a
• /
• pp.123-129
• /
• 2000

SPC is the quality improvement technique of gathering since Motorola of U.S.A. have used SPC technique as a statistical process control method for promoting 6-sigma quality improvement strategy in 1988. In Korea, small and medium-sized enterprises are needed building of a system for statistical production control . In the present study, the methods of building SPC system with a moderate cost using a graphic programs of easy-to-use and high flexibility for small and medium-sized enterprises were inquired. The SPC system which enables statistic marking (maximum, minimum, mean, standard deviation, process capability index) and graph marking (X-Y coordinates and histogram) using LabVIEW 5.0, the graphic program by National Instrument Co., Ltd. was implemented in this study.

• Journal of Korean Society for Quality Management
• /
• v.30 no.4
• /
• pp.1-14
• /
• 2002

Traditional SPC techniques are looking out variation of process by fixed sampling interval and fixed sample size about every hour, the process of in-control or out-of-control couldn't be detected actually when the sample points are plotted near control limits, and it takes no notice of expense concerned with such sample points. In this paper, to overcome that, consider VSI(variable sampling interval) EWMA control charts which VSI method is applied. The VSI control charts use a short sampling internal if previous sample points are plotted near control limits, then the process has high probability of out-of-control. But it uses a long sampling interval if they are plotted near centerline of the control chart, since process has high possibility of in-control. And then a comparison and analysis between FSI(fixed sampling interval) and VSI EWMA in the statistical aspect and economic aspect is studied. Finally, we show that VSI EWMA control chart is more efficient than FSI EWMA control chart in the both aspects.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.3
• /
• pp.95-108
• /
• 2019

Quality management has become an pervasive philosophy in most sectors of business. Specific movements such as statistical quality control, quality circle, total quality management, and quality management system have become embedded in business organizations. Only the companies with competitive edge can survive in the competition in global market. KSA(Korean Standards Association) established in 1962 has launched all kinds of quality education, quality standard certification service for business, and KNQA(Korean National Quality Award) system. This article considers quality competitiveness excellent company award among KNQA. We performed a statistical analysis of audit data for quality competitiveness excellent company for three years, from 2015 to 2017. By using ANOVA and two sample t-tests, the average scores of 13 evaluation fields were significantly different depending on company size and type. We proposed ways to improve the current hall of fame system. We discovered that the average scores of 13 evaluation fields in the audit data according to years and hall of fame status were not significantly different. We also showed linear relationships among 13 evaluation fields by correlation analysis and obtained an estimated linear regression equation : Business Performance, which is a comprehensive index, as a dependent variable was significantly related to Customer Focus and Product Liability as regressor variables among 13 evaluation fields by regression analysis.