• Proceedings of the Korean Society for Quality Management Conference
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• 2004.04a
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• pp.57-63
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• 2004

CUSUM control charts are widely used to monitor processes with small shifts. CUSUM control charts, however, are less effective in detecting for recurring cycles or frequent small shifts in the process. With Shewhart control charts, we have applied the variety of run rules to check the stability of process in addition to the situations that some points fall outside the control limits. In this paper, we propose the Z-CUSUM control chart for monitoring the process with recurring cycles or frequent small shifts by use of the zone concept as like the Shewhart control charts.

• Journal of Korean Society for Quality Management
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• v.45 no.4
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• pp.943-956
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• 2017

Purpose: This paper proposes a VSS(Variable Sample Size) ${\bar{X}}$ control chart using surrogate variable and shows its effectiveness compared with FSS(Fixed Sample Size) ${\bar{X}}$ control chart using either performance variable or surrogate variable. Methods: The expected cost function of VSS ${\bar{X}}$ control chart is derived. The optimal designs are then found for numerical examples using a GA(genetic algorithm) and compared to those of the FSS ${\bar{X}}$ control charts. Results: Computational results show that VSS ${\bar{X}}$ control chart using surrogate variables is superior to FSS ${\bar{X}}$ control chart using either performance variable or surrogate variable from the economic view points. Conclusion: The proposed VSS ${\bar{X}}$ control chart will be useful in industry fields where a performance variable is not avaliable or too costly.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.179-190
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• 2008

Consumers earn a number of points for every purchase and then they can exchange a specified number of points for a desired reward in a typical loyalty program. The immediate payoff of their effort given as points is not the real reward they actually care about. It is merely an instrument (or medium) which has no value in itself. In a real world, consumers frequently choose the option with a bigger medium even though the economic value of the option is not changed by the medium. We call it 'medium effect'. In this study we explored if the size of medium affects on consumers' preferences. For this we controlled the reward options with three types of medium (small, medium, big) and measured the magnitude of preference difference among the three types of reward options. In addition, we manipulated comparability of reward options with wine and gas discount coupon. We confirmed that choosing one of two wines was easier than that of the two gas coupons. 164 respondents were allocated into three experimental groups and one control group. In three experimental groups, the ratios of the focused reward option's medium to the compared reward option's medium were different. For example, the focused reward option has 10 million points whereas the compared reward option has 10 million points for 1 million won purchase amount in the first group. Then each respondent was asked to choose one of two loyalty programs (focused program vs. compared program) in two different conditions (comparability between reward options: easiness vs. difficulty). To compare the medium effects among the experiment conditions we used chi-squares tests. The empirical results show the medium effect increases and then decreases as the ratio of reward mileages/points to purchase amount increases. Additionally, they let us know that comparability of alternatives affects on the medium effects depending on the ratio of reward mileages/points to purchase amount.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.217-219
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• 1998

Korea Water Resources Corporation (KOWACO) annually supplies about 2 billion Kwh and 7.3 billion $m^3$ with its 10 multi purpose dams and 20 water supply offices. For the proper control and management of the above utilities, sequential control equipment and SCADA/DCS have been operated and maintained. In this paper, 8 control system evaluations for hydropower dam, water supply, electric power and subway projects during 1984-1997 were reviewed and analyzed. The systematic evaluation method has been established in the points of the purpose, method, procedure, evaluation team, evaluation criteria, total evaluation table and the contents of final recommendation report. With keeping in mind the essential points, it is expected for the more effective and fair evaluation of bids.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.11 no.3
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• pp.327-334
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• 2004

Purpose: This study was done to examine the awareness and management practice of operating room nurses, to prevent nosocomial infection, to identify problems and to propose solutions. Method: The research tools used were the hospital infection control guideline and a modified version of the measurment tools used in the study of Cho (1998). The questionnaire consisted of questions on hand washing, personal hygiene and clothes control, cleaning and environment control, sterilizing supplies and disposal of contaminated materials. The collected data were analysed with the SPSS program. Results: The mean score for domain-specific awareness of nosocomial infection control was 4.81 out of a possible 5 points. The highest score was for sterilizing supplies and disposal of contaminated materials. The mean score for domain-specific practices of nosocomial infection control was 4.40, out of a possible 5 points. Sterilizing supplies and disposal of contaminated materials had the highest scores. The mean score for awareness in all domains was higher than mean score for practice. Among the general characteristics of the nurses, high awareness was found only in the provision of infection control guidelines and it had shown statistically significant difference. Examination of relation of general characteristics to practice showed that for age, career, the provision of infection control guidelines, and experience in infection control education there were statistically significant differences in the scores. For the relation between awareness of nosocomial infection control and practice, positive correlation was found in all domains, thus high awareness leads to high practice. Conclusion: Considering the result of this research, plans are needed that promote virtual practice of hospital infection control.

• Journal of Korean society of Dental Hygiene
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• v.14 no.6
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• pp.831-838
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• 2014

Objectives: The purpose of the study was to investigate the perception and practice of the infection control by empowerment in the dental hygienists. Methods: A self-reported questionnaire was filled out by 200 dental hygienists in Gyeongbuk from January 3 to February 20, 2013. Data were analyzed by SPSS 12.0 program. The instrument of impowerment was adapted from Spreitzer and consisted of 12 questions including meaning(4 questions), competency(4 questions), self-decision(4 questions), and impact(4 questions). Impowerment was score by Likert 5 scale and higher score means higher impowerment. The instrument for hand washing recognition and practice was adapted from Kim and consisted of hand washing(5 questions), personal protective clothing management(5 questions), contaminated appliance management(3 questions), sterilization(3 questions), and infection control environment(8 questions). The empowerment instrument was score by Likert 5 scale and the mean was 3.83 points. Based on 3.83, infection control recognition and practice were divided into upper group and lower group. Cronbach alpha was 0.951 in empowerment, 0.931 in recognition, and 0.924 in practice in the study. Results: Based on the average points of 3.83, the groups were divided into two groups including upper group and lower group. The upper group showed higher score in hand washing than the lower group. In the protective clothing management, the upper group changed the mask at one-hour interval(p<0.001). Conclusions: In the viewpoint of empowerment, it had a significant influence on the perception and practice of the dental infection control in the dental hygienists.

• Journal of Biosystems Engineering
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• v.29 no.2
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• pp.159-166
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• 2004

In this study, we have developed a web-based management system for greenhouse teleoperation. The remote control system consisted of a database, a web-server, a controller in greenhouse, and clients. The database in the server stored user's information and greenhouse conditions was used to manage user's login and conditioning data. The management system developed by using Java applet, which was a client program for effective and easy management of greenhouse, monitored the greenhouse in real time. Master and driver boards were installed in the greenhouse control unit. Database on flowering to collect and analyze data exchanged data with the server. The master board could be managed effectively by timer routine, repeat control within setting time, and algorithm of setting points. Also, the greenhouse conditions could be controlled by manual or remote controller(PC) through a web browser in internet. Furthermore, all of the control devices of the greenhouse were managed by remote control of using PC and checked via camera installed in greenhouse. Finally, we showed the experimental results of the system which was installed in Pusan Horticultural Experiment Station.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.40-51
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• 2019

Ginseng has a unique production system that is different from those used for other crops. It is subject to the Ginseng Industry Act., requires a long-term cultivation period of 4-6 years, involves complicated cultivation characteristics whereby ginseng is not produced in a single location, and many ginseng farmers engage in mixed-farming. Therefore, to bring the production of Ginseng in line with GAP standards, it is necessary to better understand the on-site practices of Ginseng farmers according to established control points, and to provide a proper action plan for improving efficiency. Among ginseng farmers in Korea who applied for GAP certification, 77.6% obtained it, which is lower than the 94.1% of farmers who obtained certification for other products. 13.7% of the applicants were judged to be unsuitable during document review due to their use of unregistered pesticides and soil heavy metals. Another 8.7% of applicants failed to obtain certification due to inadequate management results. This is a considerably higher rate of failure than the 5.3% incompatibility of document inspection and 0.6% incompatibility of on-site inspection, which suggests that it is relatively more difficult to obtain GAP certification for ginseng farming than for other crops. Ginseng farmers were given an average of 2.65 points out of 10 essential control points and a total 72 control points, which was slightly lower than the 2.81 points obtained for other crops. In particular, ginseng farmers were given an average of 1.96 points in the evaluation of compliance with the safe use standards for pesticides, which was much lower than the average of 2.95 points for other crops. Therefore, it is necessary to train ginseng farmers to comply with the safe use of pesticides. In the other essential control points, the ginseng farmers were rated at an average of 2.33 points, lower than the 2.58 points given for other crops. Several other areas of compliance in which the ginseng farmers also rated low in comparison to other crops were found. These inclued record keeping over 1 year, record of pesticide use, pesticide storages, posts harvest storage management, hand washing before and after work, hygiene related to work clothing, training of workers safety and hygiene, and written plan of hazard management. Also, among the total 72 control points, there are 12 control points (10 required, 2 recommended) that do not apply to ginseng. Therefore, it is considered inappropriate to conduct an effective evaluation of the ginseng production process based on the existing certification standards. In conclusion, differentiated certification standards are needed to expand GAP certification for ginseng farmers, and it is also necessary to develop programs that can be implemented in a more systematic and field-oriented manner to provide the farmers with proper GAP management education.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.6
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• pp.17-29
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• 2013

Recently, the importance of forest landscape as a visual resource has been increased, so it is emphasized that the necessity of forest landscape management through 'Forest landscape management master plan' and 'National Forest landscape belt'. As such, this study aims to suggest a method for forest landscape management plan considering visual landscape analysis and regional landscape resources in case of Sangju-si, Gyeongsangbuk-do. Accordingly, this study has investigated regional landscape resources and surveyed existing forest conditions of target area. In order to analyze the characteristics of visual landscape, landscape control points are selected through viewshed analysis. And, Forest landscape plan is suggested 3 areas considering comprehensive analysis of forest landscape resources survey and characteristics of visual landscape:the landscape resource management area, the landscape resource restoration area and the landscape resources exploit area.

• Korean Journal of Community Nutrition
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• v.12 no.3
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• pp.310-321
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• 2007

Effective and systematic sanitation management programs are necessary to prevent foodborne disease outbreaks in school foodservice operations. The purpose of this study was to identify the elements to improve in order to ensure the safety of school food service by evaluating sanitation management practices implemented under HACCP-based programs. The survey was designed to assess the level of hygiene practices of school food service by using an inspection checklist of food hygiene and safety. Fifty-four school foodservice establishments considered as poor sanitation practice groups from two year inspections by Seoul Metropolitan Office of Education were surveyed from September to December in 2005. Inspection checklists consisted of seven categories with 50 checkpoints; facilities and equipment management, personal hygiene, ingredient control, process control, environmental sanitation management, HACCP system and safety management. Surveyed schools scored $68.0{\pm}12.42$ points out of 100 on average. The average score (% of compliance) of each field was 10.7/20 (53.3%) for facilities and equipment management, 7.4/11 (67.2%) for personal hygiene, 7.4/11 (74.1%) for ingredient control, 22.4/32 (69.8%) for process control, 8.9/12 (73.8%) for environmental sanitation management, 4.2/7 (59.7%) for HACCP systems management, and 7.2/8 (89.7%) for safety management, respectively. The field to be improved first was the sanitation control of facilities and equipment. The elements to improve this category were unprofessional consultation for kitchen layout, improper compartment of the kitchen area, lacks of pest control, inadequate water supply, poor ventilation system, and insufficient hand-washing facilities. To elevate the overall performance level of sanitation management, prerequisite programs prior to HACCP plan implementation should be stressed on the school officials, specifically principals, for the integration of the system.