The purpose of this study is to understand the change of impression by comparing the uniformity lighting with the compound lighting. In previous study, we proposed a light controlling method to harmonize daylight from a window and artificial lights from a ceiling and obtained the results to support our method. We referred this method as the Adjusted Compound-Lighting Model (AC Model). The model claims that lighting in a room with a side-window are perceived as harmonious when the overall light distribution in the room is well approximated by a compound of lights from the window and the entire ceiling. The experiment is carried out with the scaled-models and mock-up spaces that were supposed to be an office space. One is lit by the uniform lighting and the other by the compound lighting in each experimental space. In order to present varying illuminance distributions, thetwo variables were used in this study. One was the ratio of thelight from the window and ceiling in the standard and evaluation box. The standard box was provided by the ratio of 20% to 40% from the window and 80% to 60% from the ceiling as two lighting ratio patterns [Wu20(=Cu80) and Wu40(=Cu60)]. And the evaluation box was provided by the light ratio of 0% to 40 from the window and 100% to 60% from the ceiling [Wcp0(=Ccp100), Wcp20(=Ccp80) and Wcp40(=Ccp60)]. The other variable was themean illuminance level in both boxes. Two level of mean illuminance (700lx and 300lx) were used in this experiment. Each lighting condition was established at equal horizontal mean illuminance level, held constant near 700lx or 300lx in both boxes. Both of them were similar in the shape of distribution when there were same ratios of lights from the window and the ceiling. Subjects were asked to evaluate the point of difference by semantic differential rating on their overall impression after comparing with two rooms. The results showed that the impressions of compound lighting were more positive score than that of uniformity lighting on the items of 'dim-bright', 'dislike-like', 'artificial-natural' and 'closed-open', and that there was no significant difference in impressions between two spaces on other items.
Na-youn Kim;Eun-sub Kim;Seok-hwan Yun;Zheng-gang Piao;Sang-hyuck Kim;Sang-jun Nam;Hwa-Jun Jea;Dong-kun Lee
Journal of the Korean Society of Environmental Restoration Technology
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제26권1호
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pp.47-59
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2023
Due to climate change and urbanization, abnormally high temperatures and heat waves are expected to increase in urban and deteriorate thermal comfort. Planting of street trees and changing the albedo of urban surfaces are the strategies for mitigating the thermal environment of urban, and both of these strategies affect the exposure and blocking of radiative fluxes to pedestrians. After measuring the shortwave and longwave radiation according to the ground surface with different albedo and the presence of street trees using the CNR4 net radiometer, this study analyzed the relationship between this two strategies in terms of thermal environment mitigation by calculating the MRT(Mean Radiant Temperature) of each environment. As a result of comparing the difference between the downward shortwave radiation measured under the right tree and at the control, the shortwave radiation blocking effect of the tree increased as the downward shortwave radiation increased. During daytime hours (from 11 am to 3 pm), the MRT difference caused by the albedo difference(The albedo of the surfaces are 0.479 and 0.131, respectively.) on surfaces with no tree is approximately 3.58℃. When tree is present, the MRT difference caused by the albedo difference is approximately 0.49℃. In addition, in the case of the light-colored ground surface with high albedo, the surface temperature was low and the range of temperature change was lower than the surrounding surface with low albedo. This result shows that the urban thermal environment can be midigate through the planting of street trees, and that the ground surface with high albedo can be considered for short pedestrians. These results can be utilized in planning street and open space in urban by choosing surfaces with high albedo along with the shading effect of vegetation, considering the use by various users.
Kim, Tae-Han;Choi, Boo-Hun;Choi, Na-Hyun;Jang, Eun-Suk
Korean Journal of Environmental Agriculture
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제37권4호
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pp.268-276
/
2018
BACKGROUND: In the month of January 2018, fine dust alerts and warnings were issued 36 times for $PM_{10}$ and 81 times for PM2.5. Air quality is becoming a serious issue nation-wide. Although interest in air-purifying plants is growing due to the controversy over the risk of chemical substances of regular air-purifying solutions, industrial spread of the plants has been limited due to their efficiency in air-conditioning perspective. METHODS AND RESULTS: This study aims to propose a vegetation-based bio-filter system that can assure total indoor air volume for the efficient application of air-purifying plants. In order to evaluate the quantitative performance of the system, time-series analysis was conducted on air-conditioning performance, indoor air quality, and comfort index improvement effects in a lecture room-style laboratory with 16 persons present in the room. The system provided 4.24 ACH ventilation rate and reduced indoor temperature by $1.6^{\circ}C$ and black bulb temperature by $1.0^{\circ}C$. Relative humidity increased by 24.4% and deteriorated comfort index. However, this seemed to be offset by turbulent flow created from the operation of air blowers. While $PM_{10}$ was reduced by 39.5% to $22.11{\mu}g/m^3$, $CO_2$ increased up to 1,329ppm. It is interpreted that released $CO_2$ could not be processed because light compensation point was not reached. As for the indoor comfort index, PMV was reduced by 83.6 % and PPD was reduced by 47.0% on average, indicating that indoor space in a comfort range could be created by operating vegetation-based bio-filters. CONCLUSION: The study confirmed that the vegetation-based bio-filter system is effective in lowering indoor temperature and $PM_{10}$ and has positive effects on creating comfortable indoor space in terms of PMV and PPD.
Purpose: This study was undertaken to review the precise morphological patter'ns of polydactyly of the foot and to evaluate outcomes of surgical interventions. Materials and Methods: The records of patients who had polydactyly of foot from 1983 to 2000 were reviewed retrospectively. 29 duplicated toes(24 patients) were analyzed. All cases were evaluated and classified with Temtamy and McKusick's axial pattern, Watanabe's morphologic pattern and level of duplication. Clinical evaluation was performed according to Phelps and Grogan's. Mean age at surgery was 5.7 years(range: 10 months$\sim21$ years). All the patients were subsequently evaluated during mean 17 months(range: 13 months-$\sim5$ years). Results: Preaxial polydactyly was seen in 3 cases, central polydactyly in 3 cases, postaxial polydactyly in 22 cases and remaining 1 case was multiple my involvement. Only 2 patients have familial history and the most common associated anomaly was hand deformity(20.8%). Clinical results were excellent in 14 cases, good in 5 cases, poor in one. 17 patients(70%) were operated before 6 years olds and they had better results than those of who were operated after 6 years olds. Conclusion: The Method of surgical correction for the polydactyly should be individualized by its morphological pattern because the purpose of operation was to give comfort in wearing shoes and patient's psychological relief. This study showed that polydactyly of the foot could be corrected surgically with good results in most cases, and the better results would be achieved if the operation is performed before preschool age according to its individualized pattern of duplication.
This study was investigated the clothing microclimate, subjective sensation for the improvement of traditional koran high school student uniform so called "Saenghwal Hanbok". For the purpose, casual hanbok school summer uniforms were made. They were made of 4 different textiles materials - P/R, P100, P/C, P/R/S for blouses, P/W, P100, P/R, P/W/F for skirts. Then their clothing microclimate, subjective sensation were tested at room temperature $25{\pm}1^{\circ}C$ and $50{\pm}10%$ R.H. Clothing Microclimates wearing on the blouses were good matched comfort temperature range. Subjective sensations wearing on the blouses were better than those of traditional koran clothes so called "Hanbok" and quite same for western style clothes. Thermal sensations were indicated some hot condition, and moisture sensations were indicated some wet condition but tactile sensations and comfortable sensations were agreeable. The temperatures of the forehead and the breast wearing on the skirts were indicated the same results with the cases of the blouses. Leg temperatures were some lower than the mean skin temperature, the other parts' temperatures were slightly higher than blouses but the mean skin temperatures were satisfied comfortable ranges. Subjective sensations wearing on the skirts were better than those of the other traditional clothes and even Western clothes. Thermal sensations and moisture sensations were resulted the same with the case of blouses. Currently, P/R material and P/W material seemed to be cool and respectively suitable for blouses and skirts in summer among the materials of modernized Korean traditional costumes and school uniforms, since those materials lowered skin temperature. But better, physiologically pleasant materials for summer clothes should be development in consideration of clothing microclimate and subjective sensation.
Walking shoes for walking and jogging have been used to enjoy lots of leisure time. Functional shoes such as walking shoes have special functions to improve body motility by changing of shoe shapes. The walking shoes could improve the motility by structural transformation of outsole as increase degrees of heel and toe. The study on insoles has not been conducted enough on the contrary of the study of outsole. The purpose of this study is to perform ergonomics analysis whether the Arch Supported insoles have an improving effect of muscle activities or not. Experiments were performed with 6 subjects who are health and haven't experienced any diseases past. EMG(Electromyography) and Foot Pressures were measured repeatedly for 5 seconds at 0 hour, after 1 hour and after 2 hours of walking. Insoles used for experiment are normal insole, insole inserted Arch Support and pad. The electrodes for EMG measurement were set on waist (erector spinae), and thigh (vastus lateralis), calf (gastrocnemius). Evaluations of EMG were analyzed by shift of MF (Median Frequency) and MPF (Mean Power Frequency). Foot Pressure was analyzed by mean pressure of feet and change of walking time. As results, Arch Support insole had larger frequency shift value than that of normal insole. Frequency shift between Arch Support insoles and normal insole showed significant difference on 95% confidence interval. And insole 1 has the highest value of frequency shift. For results of foot pressure, Arch Support insoles show continuous decreasing tendency when comparing with normal insoles by changing of times. Also, insole 1 has the highest decreasing value of foot pressure. Therefore, this study presented that the Arch Support insole can promote muscle activities and improves comfort for a prolonged walking.
Journal of the Korean Society of Clothing and Textiles
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제21권4호
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pp.669-676
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1997
The purpose of this study is to examine the effect of the improved cold tolerance resulting from cool clothing in winter on heat tolerance in summer. Ten healthy women were divided into two groups, cold group(C group) (n=5) and warm group(W group) (n=5) . In the previous study, C group was proved that their cold acclimatization was achieved through wearing cool clothing from September to February of the following year, while Wgroup was not proved because of wearing warm clothing during same period. After February, no more clothing training was continued in two groups. To determine the heat tolerance, both groups were exposed from a thermoneutral environment(25$\pm$1$^{\circ}C$, 50$\pm$5% R.H.) to a hot environment (35$\pm$1$^{\circ}C$, 50$\pm$5% R.H.) before and after clothing training, respectively September in 1994 and truly in 1995. Rectal temperature, skin temperatures, thermal sensation and comfort were measured every 10 min., and Os uptake was measured at 10, 45, 85 min. after entering the chamber for 5 min. Body weight was measured before and after the experiment and amount of local sweat was measured during the 90 min long experiment. The results are as follows: Rectal temperatures in 35'c environment of C group were increased after training when compared with before clothing, while those of W group were not changed. But the changes of rectal temperature and heat production during 90 min in hot environment were almost the same in two groups after training. And mean skin temperatures, the changes of mean skin temperatures during 90 min in hot environment, total sweat amount and local sweat amount after training were also the same in two groups. From these results, it might be supposed that the heat loss of two groups were the same but the heat production, especially heat production during rest in C group was higher than in Wgroup. This fact suggests that the increase of rest heat production from cold acclimatization in winter is maintained to summer of the following year. And mild cold acclimatization coming from westing cool clothing does not have a negative effect on heat tolerance.
The Journal of Korean Society for School & Community Health Education
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제15권3호
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pp.105-125
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2014
Background: The purpose of this study was to evaluate reliability and validity of a 27-item Korean Version of the Impact of Weight on Quality of Life in adolescents ($IWQOL-Kids^{(C)}$: Korean Version). Methods: This instrument was administered to 872 adolescents (mean z-BMI: 2.61, mean $age{\pm}SD$: $13.9{\pm}1.2$, male: 51.9%). Reliability was tested by internal consistency method and item analysis, validity test was performed by index of content validity, exploratory factor analysis, confirmatory factor analysis and concurrent validity. Sensitivity was tested by ANOVA and t-test. Analyses were performed using SPSS and Amos 18.0. Results: By an exploratory factor analysis, 4 factors were extracted; 'Body esteem' consisted of 9 items with 35.9% of variance (social life: 6 items, 10.23%, physical comfort: 6 items, 8.21%, family relations: 6 items, 7.0%). Four factors explained 61.34% of total variance. Internal consistency coefficients ranged from .766 to .929 for scales on 27 items and equal to .920 for total score for both the 26-item and 27-item tools. A confirmatory factor analysis was conducted for the convergent validity and discriminant validity. The standardized factor loadings to test the convergent validity showed more than .5(C.R<1.965) on all paths after deletion of item PC1 (avoid stairs). The average variances extracted were more than .50 and the construct reliabilities were more than .70. The average variances extracted were stronger than the squares of correlation coefficient of inter-latent variables. Conclusions: These results support that the $IWQOL-Kids^{(C)}$: Korean Version with a 26-item is a reliable and valid tool in Korean obese adolescents.
Purpose : The purpose of this study was to investigate the effect of the perceived nursing work environment (NWE) on person-centered critical care nursing (PCCN) practices among nurses in intensive care units (ICUs). Methods : A cross-sectional research design was adopted for this study; participants were 126 ICU nurses working in five hospitals in B city. From December 2018 to February 2019, a survey questionnaire on NWE and PCCN were conducted. The collected data were analyzed with a multiple hierarchical regression analysis. Results : The mean score for NWE was $2.98{\pm}0.39$. Among the factors, basic work system was the highest ($3.39{\pm}0.41$), followed by leadership of the head nurse ($3.31{\pm}0.55$), interpersonal relationships ($2.77{\pm}0.62$), and institutional support ($2.58{\pm}0.52$). The mean score for PCCN was $3.52{\pm}0.46$. Among the factors, comfort was the highest ($3.77{\pm}0.62$), followed by respect ($3.55{\pm}0.56$), compassion ($3.43{\pm}0.60$), and individuality ($3.38{\pm}0.56$). The interpersonal relationship (${\beta}=.31$, p=.001) and the number of patients per shift (${\beta}=-.23$, p=.005) had a significant effect on PCCN, accounting for 25.9% of the total variance. Conclusion : These results suggest that it is necessary to enhance the relationship-oriented culture and reduce the workload of nurses in order to improve the quality of nursing care in ICUs.
Radionuclide cardiac angiography has distinct advantages in safety, patient comfort, cost and ease of performance. This method offers diagnostic accuracy equivalent to that of cardiac catheterization. By this method the qualitative and quantitative diagnosis of the cardiac shunts are available. Also for it is repeatable with ease and more physiologic, it has application in following pre- and post-operative shunt patients. We performed the radionuclide cardiac angiographies in 147 cases of heart diseases and 26 cases of normal group. 1. The detection of left-to-right shunt was possible in 22 of 24 patients, and 2 patients were not diagnosed due to small shunt amount. (Qp/Qs<1.3) In 21 patients of right-to-left shunt, all were diagnosed by radionuclide cardiac angiography. 2. With the pulmonary time-activity curve, $C_2/C_1$ ratio was calculated. In normal control group, a range of $C_2/C_1$ ratios of $21{\sim}38%$ was established with a mean value of $28.6{\pm}4.6%$. In patients with left-to-right shunts determined by catheterization data, the range of $C_2/C_1$ ratio was $33{\sim}90%$, with a mean value of $67.8{\pm}12.2%$. 3. In 8 cases of left-to-right shunt, $Q_p/Q_s$ ratios determined by radionuclide cardiac angiography were compaired with those of cardiac catheterization. The correlation coefficient was 0.907. (P<0.001) 4. Postoperative radionuclide cardiac angiographies were done in 21 cases. 3 of 13 patients with left-to-right shunts were found to have residual shunts. 8 patients with right-to-left shunts were confirmed to have no residual shunt.
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