• Journal of Environmental Health Sciences
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• v.5 no.1
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• pp.40-45
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• 1978

We have selected 36 schools of a total of night high schools for boys and girls in seoul and measured intensity of illumination of the classroom, The corridors and the stairs that students study and live, with priority given to an illumination, a primary factor of environmental sanitation of school following is the result. 1. The maximum average intensity of illumination of the classroom is 93.2 Lux, and the minimum average intensity of illumination 39.5 Lux. Mean$\pm$S, is 59.03$\pm$22.8 Lux 2. The maximum average intensity of illumination of the corridor is 39.2 Lux, and the minimum average intensity of illumination 11.1 Lux. 3. The maximum average intensity of illumination of the stair is 11.58 Lux, and the minimum average intensity, of illumination 4.92 Lux, mean$\pm$S.D is 7.88$\pm$10.0Lux. 4. Schools with tile illumination facilities more than 50 Lux are 63.8% and less than 50 Lux are 36.2%. 5. Schools with 9-11 facilities of a source of light per classroom by a fluorescent lamp are the most as 30.50%. 6. As for the corridor, schools with the illumination equipment less than 10 Lux are 27.8%, are more than 10 Lux 72.2% 7. As for the stairs schools with the illumination equipment less than 10 Lux are 77.8%, and more than 10 Lux 10 Lux 22.2%.

• Journal of the Korean Solar Energy Society
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• v.30 no.6
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• pp.59-65
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• 2010

Analysis on turbulence intensity profile depending on wind speed is an important process to set up design condition of wind turbine in terms of fatigue load. This paper tests goodness of fit of turbulence intensity empirical equations suggested by the IEC 61400 Standards with Jejudo Gimnyeong met-tower measurement, which is erected at a seashore. Therefore sea breeze and land breeze coexist. Sea breeze case showed apparent increasing trend of turbulence intensity in a high wind speed regime due to increase of sea surface roughness. However, neither inland wind turbine standard IEC 61400-1 nor offshore wind turbine standard IEC 61400-3 fit such a trend adequately. On the other hand, the modified empirical equation of turbulence intensity of IEC 61400-3 derived from Germany FINO1 application study by considering turbulence intensity behavior in a high wind speed regime showed good agreement with the measurement. Therefore, we can reconfirm and conclude that IEC 61400-3 Ed.1 legislated in 2009 needs to be modified.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.5
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• pp.371-381
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• 2021

A machine vision inspection system consists of a camera, optics, illumination, and image acquisition system. Especially a scanning system has to be made to measure a large inspection area. Therefore, a machine vision line scan camera needs a line scan light source. A line scan light source should have a high light intensity and a uniform intensity distribution. In this paper, an offset calibration and slope calibration methods are introduced to obtain a uniform light intensity profile. Offset calibration method is to remove the deviation of light intensity among channels through adding intensity difference. Slope calibration is to remove variation of light intensity slope according to the control step among channels through multiplying slope difference. We can obtain an improved light intensity profile through applying offset and slope calibration simultaneously. The proposed method can help to obtain clearer image with a high precision in a machine vision inspection system.

• Journal of Korean Neurosurgical Society
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• v.57 no.2
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• pp.94-99
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• 2015

Objective : The purpose of our study was to assess prevalence of carotid intraplaque hemorrhage (IPH) and associations between territorial acute infarction and IPH on magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) in patients with acute neurologic symptoms. Methods : 83 patients with suspected acute neurologic symptoms were evaluated with both brain diffusion weighted imaging (DWI) and carotid MPRAGE sequences. Carotid plaque with high signal intensity on MPRAGE of >200% that of adjacent muscle was categorized as IPH. We analyzed the prevalence of IPH and its correlation with territorial acute infarction. Results : Of 166 arteries, 39 had a carotid artery plaque. Of these arteries, 26 had carotid artery stenosis less than 50%. In all carotid arteries, MR-depicted IPH was found in 7.2% (12/166). High-signal intensity on DWI was found in 17.5% (29/166). Combined lesion with ipsilateral high-signal intensity on DWI and IPH on carotid MPRAGE sequence was found in 6 lesions (6/166, 3.6%). Of patients with carotid artery plaque, MR-predicted IPH was found in 30.8% (12/39) and match lesions with high-signal intensity on DWI and MPRAGE was found in 15.4% (6/39). MR-predicted IPH was significantly higher prevalence in high-grade stenosis group (p=0.010). Relative risk between carotid MPRAGE-positive signal and ipsilateral high-signal intensity on DWI in arteries with carotid artery plaques was 6.8 (p=0.010). Conclusion : Carotid MPRAGE-positive signal in patients was associated with an increased risk of territorial acute infarction as detected objectively by brain DWI. The relative risk of stroke was increased in high-grade stenosis categories.

• Journal of the Korean Society of School Health
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• v.27 no.3
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• pp.181-188
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• 2014

Purpose: The purpose of this study was to investigate the influence of physical activity on smoking experience and smoking intensity in Korean high school students. Methods: This cross sectional study used secondary data from the 2013 Adolescent Health Behavior Online Survey. A total of 35,905 high school students were included in the study. Logistic regression was used for analysis of the influence of moderate and vigorous physical activity on smoking experience in a month and smoking intensity. Results: Adolescents with low (Adjusted OR: 1.242, 95% CI: 1.075~1.436) and moderate level (Adjusted OR: 1.094, 95% CI: 1.005~1.189) of moderate physical activity had more smoking experience than reference group, high level of physical activity. Also, smoking experience was more prevalent adolescents with low (Adjusted OR: 1.191, 95% CI: 1.064~1.333) and moderate level (Adjusted OR: 1.134, 95% CI: 1.039~1.237) of vigorous physical activity. Heavy smoking was more prevalent among adolescents who had low level of vigorous physical activity (Adjusted OR: 1.912, 95% CI: 1.347~2.712). Conclusion: Based on the results of this study, physical activity has significant influence on smoking experience and smoking intensity. Therefore, physical activity should be included smoking cessation and smoking prevention program for High School Students.

• Korean Institute of Interior Design Journal
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• v.14 no.5 s.52
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• pp.35-43
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• 2005

This study aims to explore the relationship between the spontaneous interactions of office workers and their workspace layout. The spontaneous interactions are captured by the measures regarding the 'visual interaction' between workers in their desk layouts. The measures of visual interaction then are examined by means of the office layout or desk arrangement and the properties of work patterns according to the departments, such as general affairs, sales, research and development, and planning. The study finds four types of office layout ; Type 1 with low visual interaction between workers and high intensity of visual interaction, Type 2 with high visual interaction between workers and high intensity of visual interaction, Type 3 with low visual interaction between workers and low intensity of visual interaction, and Type 4 with high visual interaction between workers and high intensity of visual interaction. The study shows that the patterns of unintentional interaction between workers varies according to the property of work and office arrangement and it also argues that the patterns of office layout are different according to properties of work.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.750-757
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• 2003

In order to determine creep stress intensity limit of high-temperature components, the usefulness of the creep work and time equation, defined as W$\_$c/t$\^$p/ = B(where W$\_$c/ = $\sigma$$\varepsilon$ is the total creep work done during creep, and p and B are constants), was investigated using the experimental data. For this Purpose, the creep tests for generating 1.0% strain for commercial type i16 stainless steel were conducted with different stresses; 160 MPa, 150 MPa, 145 MPa, 140 MPa and 135 MPa at 593$^{\circ}C$. The plots of log W$\_$c/ - log t showed a good linear relation up to 10$\^$5/ hr, and the results of the creep work-time relation for p, B and stress intensity values showed good agreement to those of isochronous stress-strain curves (ISSC) presented in ASME BPV NH. The relation can be simply obtained with only several short-term 1% strain data without ISSC which can be obtained by long-term creep data. Particularly, this relation is useful in estimating stress intensity limit for new and emerging class of high-temperature creeping materials.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.918-925
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• 2008

Controlling the light energy and major nutrients is important for high cell density culture of cyanobacterial cells. The growth phase of Anabaena variabilis can be divided into an exponential growth phase and a deceleration phase. In this study, the cell growth in the deceleration phase showed a linear growth pattern. Both the period of the exponential growth phase and the average cell growth rate in the deceleration phase increased by controlling the light intensity. To control the light intensity, the specific irradiation rate was maintained above $10\;{\mu}mol/s/g$ dry cell by increasing the incident light intensity stepwise. The final cell density increased by controlling the nutrient supply. For the control of the nutrient supply, nitrate, phosphate, and sulfate were intermittently added based on the growth yield, along with the combined control of light intensity and nutrient concentration. Under these control conditions, both final cell concentration and cell productivity increased, to 8.2 g/l and 1.9 g/l/day, respectively.

• Korean Journal of Applied Biomechanics
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• v.26 no.4
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• pp.427-432
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• 2016

Objective: The goal of this study was to systematically investigate the postural stability of dancers by providing unexpected perturbations. Method: Six female dancers and college students participated in this study. Unpredictable wait-pull balance perturbations in the anterior direction were provided to the participants during standing. Three different perturbation intensities (low, moderate, and high intensity) were used by increasing perturbation forces. Spatial and temporal stability of postural control were measured by using margin of stability (MoS) and time to contact (TtC), respectively. Results: Both MoS and TtC at moderate intensity were significantly greater in the dancer group than in the control group, but no significant differences were found at low and high intensities between the groups. Conclusion: The present study showed spatial and temporal stability of dynamic postural control in dancers. We found that the dancers were more spatially and temporally stable than the ordinary participants in response to unexpected external perturbation when the perturbation intensity was moderate at two extreme intensity levels (low and high).

• Asia-Pacific Journal of Business
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• v.12 no.3
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• pp.397-415
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• 2021

Purpose - The purpose of this study is to analyze the cost behavior of firms, taking into account both high R&D intensity and situations in which R&D activities are likely to be performed efficiently. Design/methodology/approach - During the sample period from 2002 to 2019, regression analysis is conducted on the manufacturing firms with December fiscal year listed on KOSDAQ. The degree of R&D expenditure was measured by R&D intensity. The efficient R&D situation is measured as the decline stage firms in the KOSDAQ market, which are relatively smaller than the KOSPI market. Findings - Firms in the decline phase and high R&D intensity showed the cost stickiness. Because these firms anticipate an optimistic future, they do little to cut current costs even if their current sales decrease. Research implications or Originality - Firstly, it is confirmed that both the extent of R&D expenditure and the situation in which R&D will be effectively performed are important in the study of cost behavior. Secondly, we present a new perspective on strategy research that favors the use of cost advantage strategy related to cost anti-stickiness for the decline firms.