• Title/Summary/Keyword: Conduction model

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Heat Budget Analysis of Light Thin Layer Green Roof Planted with Zoysia japonica (한국잔디식재 경량박층형 옥상녹화의 열수지 해석)

  • Kim, Se-Chang;Lee, Hyun-Jeong;Park, Bong-Ju
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.6
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    • pp.190-197
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    • 2012
  • The purpose of this study was to evaluate thermal environment and heat budget of light thin layer green roof through an experiment in order to quantify its heat budget. Two concrete model boxes($1.2m(W){\times}1.2m(D){\times}1.0m(H)$) were constructed: One experiment box with Zoysia japonica planted on substrate depth of 10cm and one control box without any plant. Between June 6th and 7th, 2012, outside climatic conditions(air temperature, relative humidity, wind direction, wind speed), evapotranspiration, surface and ceiling temperature, heat flux, and heat budget of the boxes were measured. Daily maximum temperature of those two days was $29.4^{\circ}C$ and $30^{\circ}C$, and daily evapotranspiration was $2,686.1g/m^2$ and $3,312.8g/m^2$, respectively. It was found that evapotranspiration increased as the quantity of solar radiation increased. A surface and ceiling temperature of those two boxes was compared when outside air temperature was the greatest. and control box showed a greater temperature in both cases. Thus it was found that green roof was effective in reducing temperature. As results of heat budget analysis, heat budget of a green roof showed a greater proportion of net radiation and latent heat while heat budget of the control box showed a greater proportion of sensible heat and conduction heat. The significance of this study was to analyze heat budget of green roof temperature reduction. As substrate depth and types, species and seasonal changes may have influences on temperature reduction of green roof, further study is necessary.

A Study about the Factors Affecting Hearing loss in Adolescent's use of Personal Cassette Players(PCPs) (휴대용 카세트 사용 청소년의 청력관련 요인)

  • Lim, Kyung-Hee;Park, Kyung-Min;Park, Myung-Hwa
    • Research in Community and Public Health Nursing
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    • v.12 no.1
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    • pp.125-141
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    • 2001
  • The purpose of this study was to investigate the factors affecting hearing loss in adolescent's use of PCPs, and to give the basic data for adolescent's hearing conservation program development and prevention education against their hearing loss. This study was a descriptive research about three factors affecting hearing loss; the knowledge and attitude about noise, the perception of hearing loss and the hearing threshold. The subjects of this study were 383 students in two general high schools and two vocational high schools in Teagu. They have been using PCPs but with no current or past ear disease. This study was carried out from Sep. 1. 2000 to Oct. 24, 2000. The instrument used for the knowledge and attitude about noise was a questionnaire developed by Rhee. Kyung Yong and Yi. Kwan Hyung(1996). The instrument used for the perception of hearing loss was a Smith Hearing Screening Questionnaire. A Belton Model 112 Audiometer. air-conduction hearing test instrument. was used for the hearing threshold. Data was analysed by a SPSS/Win 10.0 program with frequency. percentage, t-test. ANOVA and pearson correlation. The results of this study were as follows; 1. The average of concern about hearing scored the highest $3.66{\pm}0.70$. The average of perceived susceptibility scored $2.64{\pm}0.85$ and the average of knowledge about noise scored $2.13{\pm}0.56$. The average of total knowledge and attitude about noise scored $2.82{\pm}0.46$. The average of discomfort of hearing loss($2.51{\pm}0.81$) scored higher than that fear of hearing loss($1.35{\pm}0.53$). The average of total perception of hearing loss scored $1.93{\pm}0.59$. The hearing threshold of the subjects scored the highest at 500Hz(Lt. $23.21{\pm}6.62$, Rt. $23.39{\pm}7.02$) and scored higher in order of 1000Hz, 2000Hz, 4000Hz and 8000Hz. 2. The knowledge and attitude about noise and the perception of hearing loss were both affected only by one important characteristic, which was general and vocational high schools. The knowledge and attitude about noise raked (t=5.258, p=0.000), and perception of hearing loss raked(t=2.241. p=0.026). However. several other important characteristics also impacted significantly on the knowledge and attitudes about noise. They included grade (t = 1. 987. p=0.048), father's education(F=2.745. p=0.043), marks(F=3.157, p=0.044), drinking(t=2.307, p=0.022) and smoking(t=2.587, p=0.010). The left hearing threshold differed significantly by sex at 1000Hz(t=5.175, p<0.001) and 8000Hz (t=3.334, p<0.01). According to general and vocational high schools (p<0.001), at 500Hz (t=-5.056), 1000Hz (t=-5.253), 2000Hz (t=-4.905), 4000Hz (t=-4.704) and 8000Hz (t=-5.204) significant differences were also shown. Marks were significant at 1000Hz (F=3.824, p<0.05) and drinking was found to be significant at 500Hz(t=2.203, p<0.05). The right hearing threshold differed significantly by sex at l000Hz(t=5.557. p<0.001). 4000Hz(t=2.234. p<0.05) and 8000Hz (t=2.730. p<0.01). According to general and vocational high schools(p<0.001) at 500Hz (t=-4.730), 1000Hz(t=-6.271). 2000Hz (t=-4.573). 4000Hz(t=-3.554) and 8000Hz (t=-3.405) significant differences were also shown. Grades impacted at 500Hz(t=2.201. p<0.05) and 4000Hz(t=2.511. p<0.05), while marks were significant at l000Hz(F=4.1l5. p<0.05) and drinking was significant at 500Hz(t=2.333. p<0.05). 3. The left hearing threshold in accordance with use of PCPs differed significantly at 2000Hz(F=2.996. p=0.03l) according to volume level and at 8000Hz(F=2.197. p=0.022) according to duration${\times}$hours per day. The right hearing threshold differed significantly at l000Hz(F=3.075. p=0.028) according to volume level and at 8000Hz(F=2.925. p=0.034) according to duration. 4. The knowledge and attitudes about noise showed a light positive correlation with the perception of hearing loss. A positive correlation was shown. as stated previously in all Hz, between the left hearing threshold and the right hearing threshold, especially the highest correlation at 2000Hz(r=0.761. p=0.000). This study has shown that the factors related to adolescent's use of PCPs are important as they impact significantly an adolescent's hearing. These results then indicate that in future, when designing a hearing conservation program and prevention education this data should be considered.

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Association between MIR149 SNPs and Intrafamilial Phenotypic Variations of Charcot-Marie-Tooth Disease Type 1A (샤르코-마리-투스병 1A형(CMT1A)의 가족내 표현형적 이질성과 MIR149 SNP에 대한 연관성 연구)

  • Choi, Yu Jin;Lee, Ah Jin;Nam, Soo Hyun;Choi, Byung-Ok;Chung, Ki Wha
    • Journal of Life Science
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    • v.29 no.7
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    • pp.800-808
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    • 2019
  • Charcot-Marie-Tooth disease (CMT) is a group of rare peripheral neuropathies characterized by progressive muscle weakness and atrophy and areflexia in the upper and lower extremities. The most common subtype of CMT is CMT1A, which is caused by a tandem duplication of the PMP22 gene in the 17p12 region. Patients with CMT1A show a loose genotype-phenotype correlation, which suggests the existence of secondary genetic or association factors. Recently, polymorphisms of rs71428439 (n.83A>G) and rs2292832 (n.86T>C) in the MIR149 have been reported to be associated with late onset and mild phenotypic CMT1A severity. The aim of this study was to examine the intrafamilial heterogeneities of clinical phenotypes according to the genotypes of these two SNPs in MIR149. For this study, we selected 6 large CMT1A families who showed a wide range of phenotypic variation. This study suggested that both SNPs were related to the onset age and severity in the dominant model. In particular, the AG+GG (n.83A>G) and TC+CC genotypes (n.86T>C) were associated to late onset and mild symptoms. Motor nerve conduction velocity (MNCV) was not related to the MIR149 genotypes. These results were consistent with the previous studies. Therefore, we suggest that the rs71428439 and rs2292832 variants in MIR149 may serve as genetic modifiers of CMT1A intrafamilial phenotypic heterogeneity, as they have a role in the unrelated patients. This is the first study to show an association using large families with variable clinical CMT1A phenotypes. The results will be helpful in the molecular diagnosis and treatment of patients with CMT1A.