• 한국환경보건학회지
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• 제23권2호
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• pp.89-97
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• 1997

Most of urban streams in Korea have been changed channel forms and suffered from direct inflow of domestic sewage, etc. Therefore, maintenance of structure and function of those ecosystem are hard. The present study was carried out to examine the life survival maintenance ability of the stream by community analysis of aquatic animals in typical urban stream (Jungrang stream) in Seoul. The aquatic animals were composed of 31 species, 18 families, 8 orders, 5 classes in 4 phyla. Seasonal species number showed big fluctuation between 8 species in Winter and 24 species in Autumn. Major dominant species in Jungrang stream were Tubificidae sp.1, Chironomidae sp.1, Chironomidae sp.2 and Physa acuta, and above endurance species for water pollution occupied very high dominance indices. But, Cercion hieroglyphicum, Ischnura asiatica, Rantra chinensis, Herochares striatus, Agabus japonicus in benthic macroinvertebrates of a few individuals are appeared. Also, fry of Carassius auratus and Silurus asotus in fish are occurred. Therefore, we can be inferred on posibility of growth and spawning of above species in the stream. Jungrang stream has a small quantity of natural riffle areas, ponds and watergrass areas by channel form of water course. Aquatic animals in Jungrang stream has been suffered by reduction of self-purification reaction ability and have mass production of attached algae on the stream bed. For analysis of fluctuation of life survival maintenance ability in Jungrang stream, long-term survey is needed.

• Industrial Engineering and Management Systems
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• 제8권4호
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• pp.221-227
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• 2009

There are customer services jointly provided by two facilities so that each customer will complete the course made up of both facilities' sub-services. The two facilities are assumed invested respectively by an infrastructure owner and one subordinate facility owner, whose partnership is built on their capital investments. This paper presents a mathematical model of Stackelberg competition between the two facility owners to derive their optimal Nash equilibrium. In this study, each facility owner's profit is consisted of fixed revenue fractions of sold services, operating costs (including depreciation cost) and maintenance costs of her facility. The maintenance costs of one facility are incurred both by failures and deterioration due to usage. Moreover, for both facilities, failures are rectified immediately by minimal repairs and preventive maintenance is carried out at a fixed time epoch. Additional assumptions are also employed to develop the model such as customer arrivals are manipulated to follow a Poisson process, and each facility's lifetime is independently Weibull-distributed. The Stackelberg game proceeds as follows. At the first stage of decision making process, the infrastructure owner (acting as a leader) decides the allocation of revenue shares based on her self-interest. After observing the allocation of revenue shares, the subordinate facility owner determines her own optimal price of services. This paper investigates actions and reactions of the two partners in the system. Then analytical conditions are proposed to achieve a unique optimal Nash equilibrium. Finally, some suggestions for further research are discussed.

• 한국치위생학회지
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• 제13권3호
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• pp.403-410
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• 2013

Objectives : This study aims to provide the basic data for the maintenance and management of healthy implants through finding out the educational experience of toothbrushing and the oral hygiene management for the implant patients and to determine the maintenance measure. Methods : From April 1 to october 1, 2012, 250 patients in the dental clinic in Daejeon completed the self-reported questionnaire. Results : As for the educational experience of toothbrushing, 66.4 percent received the training for toothbrushing and 33.6 percent had not received the training for toothbrushing. Those who brushed three times a day accounted for 74.1 percent. Those who received the training for toothbrushing comprised 56.0 percent and took regular check up of every 6 months. Approximately 50.0% received regular scaling service every 6 months. Periodical medical check up comprised 55.6% among those who received toothbrushing education. Approximately 63.9% thought that periodical medical check up is the most important to maintain oral health. Conclusions : There were important factors for oral health. They were tooth-brushing, the utilization of various oral hygienic products, and the awareness of importance of oral hygiene management. The customized education program for the general public should be implemented as regular as possible.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.373-375
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• 2007

Through Flow Technology offers unparalleled advantages for the manufacturing of flat panel displays using inkjet technology, including: outstanding reliability, self-maintenance, selfpriming and simple set up. The Xaar 1001 GS6 is the first product incorporating this technology. The concept and test results will be presented.

• 여성건강간호학회지
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• 제10권3호
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• pp.218-225
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• 2004

Purpose: The study was performed to identify exercise self-efficacy, depression, and stress by the stage of change in exercise behavior in middle aged women. Method: The subjects consisted of 317 women residing in B city by convenience sampling. The collected data was analyzed by the SPSS/WIN program. Result: The subjects were distributed in each stage of exercise behavior change: There were 53 subjects in the pre-contemplation stage, 86 subjects in the contemplation stage, 88 subjects in the preparation stage, 51 subjects in the action stage and 39 subjects in the maintenance stage. Analysis of variance showed that exercise self-efficacy (F=39.9, p<.001), depression (F=5.58, p<.001), and stress (F=6.33, p<.001) were significantly associated with the stages of exercise behavior change. There was a significant negative correlation between the stage of change and depression, and the stage of change and stress, but a significant positive correlation between the stage of change and self- efficacy, depression and stress. Conclusion: This study identified that exercise self-efficacy, depression and stress were significant variables to explain a possible relationship with exercise stages of middle aged women. This study provides new information to influence the development of better health promotion and exercise intervention for middle aged women in the community.

• 성인간호학회지
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• 제15권2호
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• pp.236-246
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• 2003

Purpose: The purpose of this study was to examine the differences of the process of change, decision making, self-efficacy and perception of subjective health according to the stages of exercise behaviors suggested by transtheoretical models among older adults. Method: The subjects consisted of 291 older adults. Trained research assistants interviewed the older adults using structured questionnaires. ANOVA analyses with post hoc test were used to examine the mean differences for each stage of exercise behavior using SPSS for windows. Result: The subjects were divided into five stages of exercise behavior: 24.4% precontemplation, 12.4% contemplation, 17.9% preparation, 12.4% action, 33.0% maintenance stage. There were significant differences in process of change, decision making, self-efficacy and subjective health perception according to the exercise stage of change. 'Self-liberation' and 'stimulus control' were important strategies for intention of exercise, while 'reinforcing management' for the actual practice of exercise. 'Self-efficacy' was an effective strategy to change older adults from pre-contemplation to preparation stage. Conclusion: For exercise intervention, older adults should be classified into groups according to their stages of exercise behaviors and provided effective individualized intervention depending on their stage.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.589-590
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• 2013

The fast development of electronic devices towards wireless, portable and multi-functionality desperately needs the self-powered and low maintenance power sources. The possibility to coupling the nanogenerator to wearable and portable electronic device facilitates the self powered device with independent and self sustained power source. Nanogenerator has ability to convert the low frequency mechanical vibration to electrical energy which is utilized to drive the electronic device [1]. The self powered power source has the ability to generate the power from environment and human activity has attracted much interest because of place and time independent. The human body motion based energy harvesting has created huge impact for future self powered electronics device applications. The power generated from the human body motion is enough to operate the future electronic devices. The energy harvesting from human body motion based on triboelectric effect has simple, cost-effective method [2, 3] and meet the required power density of devices. However, its output is still insufficient to driving electronic devices in continues manner so new technology and new device architecture required to meet required power. In the present work, we have fabricated the triboelectric nanogenerator using PDMS polymer. We have studied detail about the power output of the device with respect to different polymer thickness and varied separation distance.

• 한국간호교육학회지
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• 제21권1호
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• pp.65-74
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• 2015

Purpose: This study was carried outto compare dietary self-efficacy, obesity stress, and obesity-related quality of life (OQOL) according to BMI and stages of change in vegetable consumption. Methods: A convenience sample of 326 nursing students agreed to complete a questionnaire. Data were collected from October 7 to October 18, 2013. Results: Obesity stress and obesity-related quality of life were significantly different according to BMI. Dietary self-efficacy showed a significant difference between the pre-contemplation/contemplation stage, preparation stage, and action/maintenance stage (F=50.18, p<.001). With obesity stress, there was a significant difference between the PC/C, P, and A/M stages (F=17.63, p<.001). Dietary self-efficacy had a positive correlation with OQOL (r=.11, p<.001) and a negative correlation with obesity stress (r=-.14, p=.012). And obesity stress had a negative correlation with OQOL (r=-.45, p<.001). Conclusion: These findings emphasize that nutritional-intervention programs for changes in behavior during the PC/C and P stages of change in vegetable consumption need to develop strategies to enhance dietary self-efficacy for nursing students.

• 가정과삶의질연구
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• 제23권3호
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• pp.1-16
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• 2005

This study explored the elements, types, and determining factors of successful aging for the Korean elderly. In order to examine the expectations of the Korean elderly, a sample of 377 elderly aged 65 and over living in Seoul and Kyunggi areas was selected and interviewed. The elements of successful aging that the Korean elderly pointed out in the interviews were: 'peaceful and comfortable life', 'self-maintenance,' 'secure social support,' and 'ostentation.' The expected elements of successful aging were further classified into three types of successful aging: 'idealized expectation.' 'self-centered expectation,' 'balanced self-other expectation.' The elderly groups sorted by the types exhibited significant differences in terms of demographic characteristics, self-evaluated economic status, and self-evaluated health status. The variables that affected the expectations were age, level of education, marital status, gender, and self-evaluated health condition. However, further analysis revealed that the factors that affected the expectation for successful aging were different for male and female elderly. The results suggest that the successful aging of Korean elderly should be understood in the context of Korean society and culture. The results could be used to better understand varied and unique life of Korean elderly, as well as in establishing a basis of intervention that meets the specific demands of the Korean elderly.

• KEPCO Journal on Electric Power and Energy
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• 제7권2호
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• pp.295-299
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• 2021

Recently, interest in maintenance has been increasing due to the enlargement and aging of infra structures. Therefore, a new paradigm is required to secure and improve the durability of structures differentiated from the past. Accordingly, research on smart concrete incorporating the concept of self-healing into concrete is being actively conducted. In this study, the crack healing performance and durability performance of self-healing concrete applied with a hydrogel containing biomineral-forming microorganisms were evaluated. As a result of evaluating the dispersion of the hydrogel in concrete, it was confirmed that the hydrogel was well distributed in concrete matrix with a dispersion coefficient of 0.35 to 0.46. The crack healing performance evaluation was verified by a water permeability test, and showed a recovery rate of 95% or more at the age of 28 days, confirming the applicability of self-healing concrete. The durability performance of self-healing concrete was evaluated in terms of resistance to penetration of chloride ion and freezing and thawing. Regardless of the mixing of the hydrogel, the same level of durability performance was shown for various compressive strength level. Therefore, it was confirmed that the microbial admixture did not affect concrete durability. In the future, long-term crack healing performance and durability verification studies should be supplemented.