• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.348-355
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• 2002

To know characteristics of water quality in Saemankeum area, we were investigated the water quality of surface layer from July of 1999 to June of 2000. The concentrations of COD and chlorophyll a were in the range of $0.64\~6.40$ (mean 1.96)mg/L, $1.95\~51.55$ (mean 11,07)$mg/m^3$, respectively. The annual mean concentrations of DIN, DIP were found to be 21.182 $\mu$g-at/L and 0,655 $\mu$g-at/L respectively, which were exceeding second grade of seawater quality standard. The nitrogen ratio to the phosphorus was lower than 1. Therefore, nitrogen was playing an important role in phytoplankton growth as limiting factor in study area. Mean values of eutrophication index were exceeding 1, which was the eutrophication criteria. Especially Mankyung and Dongjin estuary were shown over 10 as eutrophication index. Therefore, Saemankeum area could be evaluated to possibility area for eutrophication. Released rate for ammonia nitrogen and phosphate phosphorus from sediments were 62.92 ${\mu}g-at/m^3/hr$ and 6.71 ${\mu}g-at/m^3/hr$, respectively.

• Journal of Sasang Constitutional Medicine
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• v.33 no.1
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• pp.102-108
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• 2021

Objectives The purpose of this study was to identify differences in sleep by Sasang constitutional type using Pittsburgh Sleep Quality Index(PSQI). Methods The subjects of this study were 3,578 people who had information on Sasang constitutional type and PSQI among the data established at the Korean Medicine Data Center. We compared each item score in PSQI (subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbance, use of sleep medication, daytime dysfunction) and PSQI global scores by Sasang constitutional type using analysis of variance. Logistic regression was conducted to calculate the odds ratio of poor sleep by Sasang constitutional type. Results & Conclusions The SE type showed statistically significantly higher scores than the TE type and SY type in subjective sleep quality, sleep latency, habitual sleep efficiency, sleep disturbance, and PSQI global score, indicating poor sleep compared to other constitutional types. The odds ratio for poor sleep also shows that even after adjusting sex, age, height, and weight, the SE type was significantly higher than other constitutional types, indicating that the SE type could be a risk factor for poor sleep.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.391-393
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• 2005

This paper studies flicker evaluation considering power quality disturbance. A flicker problem with light device irritates human's eyes. Also, the flicker problem has an influence on adverse effect such as rolling device and rotating device. However, a study of flicker evaluation is not complete. A flicker is measured and evaluated at monitoring point. But we consider power quality disturbances such as voltage sag and transient that cause fault and inverter/breaker switching. Power quality disturbances affects flicker evaluation. A flicker evaluation index increases. Therefore, we consider power quality disturbances. We detect voltage sag and transient using wavelet and evaluate flicker without flicker index including power quality disturbances.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.513-518
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• 2013

The purpose of vehicle horn sound is for warning to pedestrians. In the past, the main development factor is to match the regulation level. But nowadays perceived quality is more important than level itself. In this study, we measure variety horn sound and evaluate its signals through the jury evaluation aimed at making horn sound quality index. Each contribution of the noise path for sound quality is identified and the target values and methods for implementing the luxurious horn sound are suggested. Finally, we developed, horn component and improve horn mounting condition for luxurious horn sound.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.1
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• pp.37-45
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• 2022

It is well known that the Kano model measures customer satisfaction and classifies quality attributes into must-be, attractive as well as one-dimensional. The main purpose of this study is to investigate the dynamics of e-learning quality attributes by applying the proposed method using Kano's satisfaction index in the rapidly changing online learning environment. For this, the current study examined 27 e-learning quality attributes and conducted a comparative study using Kano's results obtained in 2013 and 2020. The result shows that the dynamics of quality attributes suggested by Kano(2001) is confirmed in the case of e-learning. The proposed approach shows better results in terms of Kano's direct classification method, and has potential application areas such as IPA(Importance-Performance Analysis) in the area of risk assemement. Some suggestions for better understanding of the proposed SI-DI diagram are also included in this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.511-519
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• 2021

This study examined the effects of the levels of depression and oral health on the quality of life in workers participating in a self-sufficiency program in the Seoul metropolitan area. As for the study method, a questionnaire survey was conducted from July 26 to September 5, 2020, targeting 569 workers participating in a self-sufficiency program. Depression, Perio-Quotient Index, self-diagnosed oral symptoms, and oral health quality of life were the survey items investigated. The results were as follows. In the workers with systemic diseases, depression, Perio-Quotient Index, oral symptoms, and oral health quality of life were all negative. The level of depression was highly negative in both Perio-Quotient Index, oral symptoms, and oral health quality of life, showing statistically significant differences. In addition, depression showed a strong negative correlation with the Perio-Quotient Index, oral symptoms, and oral health quality of life. Depression, Perio-Quotient Index, and particularly oral symptoms negatively affected oral health and the quality of life. As workers participating in a self-sufficiency program are vulnerable to oral health problems, oral health education is required for the correct awareness and management of oral health, and oral health policy improvement for socially vulnerable groups is essential to ensure continued oral health management.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.10
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• pp.1451-1457
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• 2004

Bone density parameters of children, unlike that of adult, might reflect growth effect along longitudinal direction as well as bone mass. The clinical test was performed for 859 male/female children with age 6-16 years. Ultrasonic imaging system was used to measure bone density, and relationship of bone density to age was evaluated. The bone quality index appeared to be highly correlated with age for male/female children. It was found that bone quality index rose rapidly in the first growth period. The bone quality index was then kept almost unchanged in the period of puberty, and slowly rose after puberty. It was also found that growth of female stopped earlier than that of male. Also, if more clinical examinations are performed by applying various sizes of region of interest, relationship between bone density and age is expected to be more reliable.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.473-478
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• 2007

We analyze competitiveness of material and component industry(MCI) of Korea, China and Japan using trade data, OECD ITCS database with HS-code system. We use unit price indices, export unit price index, import unit price index, and TOT unit price index. These indices provide quality information from trade data of value and quantity. Our results show that there are quality gaps among three countries, and that China expand development potential, and the results vary as sectors. It implies that R&D investment to improve quality of MCI products is essential and that sector-specific policy is necessary.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.33-48
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• 2010

The purpose of this study is to empirically analyze the productivity change of the 10 Single PPM Certification Company in the 3 Industry(Electronics, Motor-Parts, Machines). In this study, Productivity change over the time in Korean small and medium sized firms in the 3 industries by the bootstrapped Malmquist Productivity Index(MPI). The traditional Malmquist Productivity Index(MPI) and Data Envelopment they could lead to wrong evaluations of the efficiency and productivity scores. In this paper, DEA and a MPI are combined with a bootstrap method in order to provide statistical inferences that analyze the performance of the Single PPM Certification Company. The data cover the period between 2004 and 2007. The result of this paper reveals : 1) The electronic industries(Motor-Parts, Machines). 2) average productivity Progress of the 7DMU(Electronics), 1DMU(Motor-Parts) and none(Machines).

• Journal of the Korean Society of Marine Environment & Safety
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• v.3 no.S1
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• pp.77-90
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• 1997

the observations in situ and the seawater analyses were conducted in July and August, 1996 for the purpose of evaluating the characteristics of seawater quality centered on eutrophication in Mokpo harbour. By applying the OECD standards of trophic classification to the parameters such as secchi depth, total inorganic nitrogen, phosphate phosphorus and chlorophyll-a, the trophic level of seawater in Mokpo harbour was evaluated to be in eutrophic state in summer. By the estimation of pollution index with relation to eutrophication, the seawater quality of Mokpo harbour was evaluated to be under the regular grades and this evaluation was found to be different from the results of evaluation obtained by the environmental index of single parameter, chemical oxygen demand. By the estimation of eutrophication index, the seawaters of Mokpo harbour were shown to have the high potentiality of red tide occurrence.