• Korean Journal of Optics and Photonics
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• v.17 no.1
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• pp.94-98
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• 2006

An optical microphone based on a dual-core fiber collimator and a membrane type micromirror serving as an optical head and a reflective diaphragm respectively was implemented. The micromirror diaphragm is suspended by a thin silicon bar linked with a frame, thus it is subject to a displacement induced by acoustic waves. The optical head incorporating two collimators integrated in a single housing gives light to and receives it from the diaphragm, rendering the optical microphone structure simple and compact. This dual-core collimator having a slowing varying beam profile facilitates the initial alignment of the optical head with the diaphragm, especially the distance between them. For the assembled microphone, the static characteristics were investigated tofind the operation point defined as the optimum distance between the head and the diaphragm, and a frequency response with a variation of about $\pm$5 dB for the range of up to 3kHz was achieved.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1164-1168
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• 2007

질소 및 인 동시제거 공정 중 대표적인 연속회분식반응조(Sequencing Batch reactor: SBR)는 비교적 간편한 운전방법과 저렴한 건설비, 유입수의 부하변동에 큰 영향을 받지 않는 소규모 하수처리에 적합한 공정으로 알려져 있다. 또한 SBR 공정은 기존 활성슬러지 공법에 비해 적은 부지로 많은 양의 폐수를 처리할 수 있고 유입수 수질 및 유량변동에 따라 다양한 운전주기를 변화할 수 있으며, 유기물 제거뿐만 아니라 반응조의 변형에 의해 영양염류의 제거가 가능한 장점이 있다. 본 연구에서는 bench scale SBR 실험을 통하여 질산염의 탈질속도 및 용해성 인의 흡수와 방출속도를 측정하고, SBR 공정의 무산소조건에서 인흡수 및 탈질을 동시에 수행하는 DPB 존재의 가능성을 파악하고자 하였다. 연구결과 무산소조건에서 S-P의 방출과 흡수가 동시에 진행되었으며, 무산소조건에서 S-P의 방출속도는 $0.08{\sim}0.94\;kgS-P/kgMLSS{\cdot}d$, 흡수속도는 $0.012{\sim}0.1\;kgS-P/kgMLSS{\cdot}d$를 나타내었다. 무산소조에서 S-P의 방출 및 흡수가 진행되는 동안 탈질과정도 함께 진행되었으며, 각각의 F/M비에서 탈질속도를 측정한 결과 F/M비 $0.44\;kgCOD/kgMLSS{\cdot}d$에서는 최대 $0.16\;kgNO_3^-N/kgMLSS{\cdot}d$의 탈질속도를 나타내었다. S-P이 방출되지 않는 경우와 방출되는 경우의 비탈질속도를 비교한 결과 S-P이 방출되지 않는 경우의 비탈질속도가 S-P이 방출되는 경우의 비탈질속도보다 높았다. 이렇게 S-P이 방출되는 경우의 비탈질속도가 더 낮은 이유는 무산소 조건에서 탈질과 S-P의 방출 및 흡수가 동시에 일어나는 경우 S-P의 방출에 관여하는 미생물과 탈질에 관여하는 미생물간의 경쟁반응 때문으로 판단된다.응답법의 적용이 가능함을 보였고, 이는 보다 복잡한 관망에서의 천이류 해석이 가능함을 시사한다.$경상도지리지$\lrcorner$(慶尙道地理志)에는 상주가 8곳으로 1/3의 자기 생산을 담당하고 있었다. $\ulcorner$경상도지리지$\lrcorner$(慶尙道地理志)에는 $\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와 동년대에 동일한 목적으로 찬술되었음을 알 수 있다. $\ulcorner$경상도실록지리지$\lrcorner$(慶尙道實錄地理志)에는 $\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와의 비교를 해보면 상 중 하품의 통합 9개소가 삭제되어 있고, $\ulcorner$동국여지승람$\lrcorner$(東國與地勝覽) 에서는 자기소와 도기소의 위치가 완전히 삭제되어 있다. 이러한 현상은 첫째, 15세기 중엽 경제적 태평과 함께 백자의 수요 생산이 증가하자 군신의 변별(辨別)과 사치를 이유로 강력하게 규제하여 백자의 확대와 발전에 걸림돌이 되었다. 둘째, 동기(銅器)의 대체품으로 자기를 만들어 충당해야할 강제성 당위성 상실로 인한 자기수요 감소를 초래하였을 것으로 사료된다. 셋째, 경기도 광주에서 백자관요가 운영되었으므로 지방인 상주지역에도 더 이상 백자를 조달받을 필요가 없이, 일반 지방관아와 서민들의 일상용기 생산으로 전락하여 소규모화 되었을 것이라고 사료된다.장 운동기능을 향상시키는 유효성분의 보강 등이 필요하다는 점도 알 수 있었다.더불어 산화물질 해독에 관여하는 다른 유전자

• Journal of the Korean Society for Railway
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• v.19 no.1
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• pp.20-28
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• 2016

Curved squeal noise may result when railway vehicles run on curved tracks. Contact between the wheels and the rails causes a stick-slip phenomenon, which generates squeal noise. In order to identify the mechanism of the squeal noise systematically, a scaled test rig has been fabricated. Knowledge of the contact forces between the wheels and the rail rollers is essential for investigating the squeal noise characteristics; however, it is difficult to measure there contact force. In this study, contact forces have been calculated indirectly according to the modal behavior of the subframe that supports the rail roller and the responses at specific positions of that subframe. In order to verify the estimated contact forces, the displacements at the contact points between the wheels and rail rollers have been calculated from the estimated forces; the resulting values have been compared with the measured displacement values. The SPL at the specific location has been calculated using the estimated contact forces and this also has been compared with the SPL, measured in a semi-anechoic chamber. The comparisons in displacements and SPLs show good correlation.

• Journal of Information Technology and Architecture
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• v.9 no.3
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• pp.287-301
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• 2012

Against Nonaka's seminal work in 1999, this study aims to investigate various influencing factors on knowledge-transfer channels of Korean academics. To do this, we surveyed 20,000 Korean academics in science and engineering with regard to factors involved in their formal and informal collaborative activities with firms. In particular, we focus on the individual characteristics of the academics when the channels are changed from informal channels (e.g. consulting) to formal channels (e.g. licensing), as the codification of knowledge is important when it is spilled over. According to the results, male academics with a longer career and in the field of applied disciplines in a big laboratories are likely to join the transformation of the channels. Interestingly, application capacity as measured by the number of patent application is significantly and positively related to the participation of formal channels. In contrast, scientific capacity as measured by the number of papers is significantly and negatively, or in some case weakly, related to the participation. Finally, based on the findings, some policy implications are put forwarded.

• The Journal of the Acoustical Society of Korea
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• v.41 no.3
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• pp.287-301
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• 2022

The present study aims to investigate the difference of soundscape evaluation results from on-site field test and laboratory test which are commonly used for soundscape surveys. In order to do this, both field and lab tests were carried out at four different areas in Cheongju city. On-site questionnaire surveys were undertaken to 65 people at 13 points. Laboratory listening tests were carried out to 48 adults using recorded sounds and video. Laboratory tests were undertaken to two different groups who had experience of field survey or not. Also, two different sound reproduction tools, headphones and speakers, were used in laboratory tests. As a result, it was found that there is a very close correlation between sound loudness and annoyance in both field and laboratory tests. However, it was concluded that there must be a difference in recognizing the figure sounds between field and laboratory tests since it is hard to apprehend on-site situation only using visual and aural information provided in laboratory tests. In laboratory tests, it was shown that there is a some difference in perceived most loud figure sounds in two groups using headphones and speakers. Also, it was analyzed that there is a tendency that field experienced people recognize the figure sounds using their experienced memory while non-experienced people can not perceive the figure sounds.

• Korean Journal of Culture and Social Issue
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• v.27 no.4
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• pp.435-455
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• 2021

This study aimed to examine the effect of the income change and income level during the COVID-19 pandemic on individuals' depression, and to test how those associations may differ by gender. Participants consisted of 634 adults(M_age=44.18, SD_age=13.88, 313 females) recruited through an online research company. Participants completed a set of questionnaires that measured income change, average monthly income for the past six months, and the Korean version of CES-D. The results indicated that decreases in income, but not levels of income, significantly predicted levels of depression. Furthermore, both income change and income level interacted with gender to predict depression. Specifically, income change predicted depression only for males, while income level predicted depression only for females. These findings suggest that the effects of income-related indicators on depression during the pandemic may differ by gender. The study also offers practical implications by proposing gender as a potential factor to consider in early identification and intervention to prevent depression during the pandemic.

• Korean Journal of Culture and Social Issue
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• v.19 no.2
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• pp.235-257
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• 2013

The purpose of this study is to develop the Leisure Obsession Scale and examine the validity of the scale. The Leisure Obsession Scale was developed and identified its validity by exploratory factor analysis, confirmatory factor analysis, and correlation analysis. The Leisure Obsession Scale consists of two factors, which are 'Leisure Preoccupation' and 'Leisure Stereotype'. Those two factors indicated the reasonable fit index by confirmatory factor analysis. In addition, this scale displayed discriminant validity via measurement of obsession, workaholism, leisure anxiety, and leisure constraint. Also, the results of criterion validation analysis shows that the Leisure Obsession Scale and its subscale are correlated with measure of age, leisure information searching, intention of participation to new leisure activities, and intention of increase in leisure time. Conceptualizing leisure obsession and exploring components of leisure obsession would be valuable for understanding the nature of leisure obsession and its effects on leisure satisfaction, and suggesting more effective psychological intervention in a diverse population.

• Journal of dental hygiene science
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• v.16 no.2
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• pp.142-149
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• 2016

The number of male dental hygienists has been continuously increasing in dental services. The purpose of this study aimed to identify the relationship between job stress, job satisfaction, and turnover intention in male dental hygienists and to provide basic data to improve their job satisfaction. The study population was 110 Korean male dental hygienists working for dental clinics or hospitals. The data were collected from November 10 to December 7, 2015. After an explanation about the objective of the study, 110 questionnaires were distributed via email, and 97 responses were analyzed using SPSS. Overall averages of job stress, job satisfaction and turnover intention in male dental hygienists were 3.05, 2.92, and 3.47 out of 5, respectively. Some sub-factors of job stress, including interpersonal relationships at the workplace and future prospects of dental clinics, were proven to have statistically significant negative influence on job satisfaction (p<0.001). Regression analysis was performed with job stress and job satisfaction as independent variables and turnover intention as a dependent variable. Results showed that job stress had a positive effect on turnover intention (p<0.01) while job satisfaction had a negative effect on turnover intention (p<0.001). Job satisfaction was revealed to have statistically significant negative influence on turnover intention (p<0.001). Some of sub-factors of job stress, including work environment and future prospects of dental clinics and professional position, had a positive effect on turnover intention (p<0.05). The study showed that higher job stress led to higher turnover intention, and higher job satisfaction led to lower turnover intention. Accordingly, job stress and job satisfaction are critical factors for turnover intention in male dental hygienists.

• Journal of Preventive Medicine and Public Health
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• v.32 no.3
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• pp.361-373
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• 1999

Objectives: Receive Operating Characteristic(ROC) curve with the area under the ROC curve(AUC) is one of the most popular indicator to evaluate the criterion validity of the measurement tool. This study was conducted to develop a standardized questionnaire to discriminate workers at high-risk of work-related musculoskeletal disorders using ROC analysis. Methods: The diagnostic results determined by rehabilitation medicine specialists in 370 persons(89 shipyard CAD workers, 113 telephone directory assistant operators, 79 women with occupation, and 89 housewives) were compared with participant's own replies to 'the questionnair on the worker's subjective physical symptoms'(Kwon, 1996). The AUC's from four models with different methods in item selection and weighting were compared with each other. These 4 models were applied to 225 persons, working in an assembly line of motor vehicle, for the purpose of AUC reliability test. Results: In a weighted model with 11 items, the AUC was 0.8155 in the primary study population, and 0.8026 in the secondary study population(p=0.3780). It was superior in the aspects of discriminability, reliability and convenience. A new questionnaire of musculoskeletal disorder could be constructed by this model. Conclusion: A more valid questionnaire with a small number of items and the quantitative weight scores useful for the relative comparisons are the main results of this study. While the absolute reference value applicable to the wide range of populations was not estimated, the basic intent of this study, developing a surveillance fool through quantitative validation of the measures, would serve for the systematic disease prevention activities.

• Journal of agricultural medicine and community health
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• v.30 no.1
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• pp.101-111
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• 2005

Objectives: This study was to evaluate the compliance of hypertensive patients and its related factors registered at Community Health Practitioner Post(CHCP). Methods: 304 patients were interviewed by trained nursing students during one month(June~July 2004). The questionnaire included general charactristics, knowledge of hypertension, health education experience, constructs of Health Belief Model, self efficacy and so on. Compliance group was defined "having regularly medication and good life style". Good life style included regular exercise, non-smoking, little alcohol, low salt diet, weight control. Results: In compliance group 90.3% of man and 93.3% of woman were regularly taking hypertensive medicine, and 45.2% of man and 56.4% of woman were having good life style (compliance group). In both man and woman, the group of higher education were more compliance group, but were statistically significant were in man(p<0.05). In woman, the compliance group have significantly higher score in knowledge of hypertension(p(0.05). The compliance group have significantly higher self-efficacy score in both man and woman (p<0.05). In Health Belief Model, susceptibility and benefit were statistically significant in man, seriousness, benefit and barrier in woman(p<0.05). In multiple logistic regression analysis, education level and self efficacy in man and knowledge of hypertension, self-efficacy and benefit in woman were significant variables (p<0.05). Conclusions: It is very important to evaluate and modify life-style adding to having regularly medication in hypertensive patients registered at CHCP. To this, health education programs about benefit to compliance and the methods to improve self-efficacy should be developed for this patients.