• 제목/요약/키워드: Natural Standard

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Blower Door Test를 이용한 공동주택 자연환기시스템의 환기성능 분석 (Analysis on Ventilation Performance of Natural Ventilation Systems in Multi-Family Housing Using Blower Door Test)

  • 김민석;어진선;홍구표;김병선
    • KIEAE Journal
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    • 제16권6호
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    • pp.129-134
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    • 2016
  • Today, natural ventilation systems are widely applied in multi-family housing. However, studies using the wind data trend line of the blower door test are insufficient. Purpose: Through this study, we will propose a computational method about ventilation performance of natural ventilation systems by conducting blower door test. Method: First, we sealed the gaps between the main systems including the natural ventilation system and conducted the blower door test. Next, the natural ventilation system was opened, the blower door test was conducted, and the difference in air flow rate between when closed and when opened was checked. Blower door test was carried out with a pressure difference of 50 Pa. Result: Therefore, the ventilation performance of the natural ventilation system was checked by drawing a trend line using the data to calculate the air flow rate at 2 Pa of the natural ventilation equipment standard pressure difference.

상부자연사면 경사에 따른 토사사면의 안정성 평가에 관한 연구 (A Study on the Stability Evaluation of Soil Slope according to inclination of upper Natural Slope)

  • 이정엽;김진환;이종현;구호본
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2004년도 춘계학술발표회
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    • pp.580-585
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    • 2004
  • The purpose of this study is the stability evaluation of soil slope according to inclination of upper natural slope. Upper natural slope breeds loss of slope by inflow in slope of surface water by rainfal1 and f1uctuation of amount of materials in slope through method of cutting slope according to degree of inclination. Basis of standard inclination does not consider of inclination of upper natural slope and is presented uniformly. Therefore, in this study, analyzed stability of inclination of upper natural slope through limit equilibrium analysis. Result is same as following. First, safety factor through limit equilibrium analysis is almost direct decrease when gradient of soil slope is 1:1.2, 1:1.5. However, when gradient of soil slope is 1:1.0, 1:0.7, if sinclination of upper natural slope are $20^{\circ}$, it shows tendency that decrease of safety factor becomes low rapidly. Second, when when gradient of soil slope is fixed, inclination of upper natural slope increase tendency(maximum 3.0 times) that decrease of safety factor.

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학교 교실의 창호 배치 및 개방면적비에 따른 중간기 자연환기량 및 쾌적성 평가에 관한 연구 (A Study on Evaluation of Natural Ventilation Rate and Thermal Comfort during the Intermediate Season considering by Window Layout and Open Window Ratio)

  • 김여진;최정민
    • 대한건축학회논문집:구조계
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    • 제35권9호
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    • pp.207-214
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    • 2019
  • Natural ventilation through openings such as windows in school buildings is an efficient resource for natural cooling during the intermediate season of the year. Because the natural ventilation uses the wind outside the building, the amount of ventilation will depend not only on the wind speed and wind direction but also on the window layout and open window ratio. Therefore, in this study, the natural ventilation plans of school classroom windows are divided into 4 types and 8 cases as shown in Table 1. The characteristics of cooling effect by natural ventilation are simulated by applying Energyplus's Airflow Network Model and the comfort of the occupants is evaluated by the number of hours included in the 80% acceptability range of the ASHRAE Standard 55-2010 adaptive comfort model for the weekdays (Monday-Friday) and the class hours (08: 00-19: 00). Based on the analysis results of the above, this study presents basic data related to classroom cooling plan using intermediate season natural ventilation.

교사환경기준에 관한 연구 (A Study on Environmental Standards of School Building)

  • 홍석표;박영수
    • 한국학교ㆍ지역보건교육학회지
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    • 제1권1호
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    • pp.11-43
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    • 2000
  • The purpose of this study was, through analyzing the previous researches, to grasp the present status of environment of school building(ESB), research the sundry records of each element and, through comparative analysis of the standard of ESB in Korea, the United States, and Japan, select the normative standard of ESB, to clarify the point at issue presented in Regulation of Construction & facility Management for Elementary and and Secondary School in Korea, and to suggest an alternative preliminary standard of ESB. To carry out a research for this purpose, these were required: 1. to investigate the existing present status of ESB, 2. to make a comparative analysis of the standard of ESB in each country, 3. to suggest the normative standard of preliminary standard of ESB, 4. to analyze the controversial points of the standard of ESB in Korea, 5. to suggest an alternative preliminary standard of ESB. The conclusions were as follows: 1. Putting, through analyzing the previous researches, the existing present status of ESB together, it seemed that lighting environment, indoor air environment and noise environment were all in poor conditions. 2. In the result of a comparative analysis of the standard of ESB in Korea, Japan and the United States, in Korea the factors of each lighting and indoor air environment were not presented properly, in Japan, in lighting environment aspect, the standard on natural lighting and the factors on brightness were not presented., and in the USA the essential factors of each environment were throughly presented. In the comparison of the standards on each factor, Korea showed that the standard level presented was less properly prescribed than those of the USA and Japan but it also showed that the standard levels prescribed in the USA and in Japan were mostly similar to the standard levels in records investigated. 3. With the result of the normative standard selection on School Builiding environment factor of prescribed in this study, the controversial points of the standard of ESB in Korea were analyzed and the result was utilized to suggest new preliminary standard of ESB. 4. As the result of the analysis of the controversial points of the standard of ESB in Korea, it was found that the standard of ESB in Korea should be established on a basis of School Health Act and be concretely presented in School Health Regulation and School Health Rule. The factors of each environment was improperly presented in the existing standard of ESB in Korea. Moreover the standard of them was inferior to that of the records investigated and those of in the USA and in Japan and it also showed that the standard of it in Korea was improper to maintain Comfortable Learning Environment. 5. A suggested preliminary standard of ESB acquired through above study as follows: 1) In this study a new kind of preliminary standard of ESB is divided into lighting environment, indoor air environment, noise environment, odor environment and for above classification, reasonable factor and standard should be established and the controling way on each standard and countermeasures against it should be considered. 2) In lighting environment, the factors of natural lighting are divided into daylight rate, brightness, glare. In the standard on each factor, daylight rate should secure 5% of a mean daylight rate and 2% of a minimum daylight rate, brightness ratio of maximum illumination to minimum illumination should be under 10:1, and in glare there should not be an occurrence factor from a reflector outside of the classroom. And the factors of unnatural lighting are illumination, brightness, and glare. In the standard on each factor, illumination should be 750 lux or more, brightness ratio should be under 3 to 1, and glare should not occur. And Optimal reflection rate(%) of Colors and Facilities of Classroom which influences lighting environment should be considered. 3) In indoor air environment factors, thermal factors are divided into (1) room temperature, (2) relative humidity, (3) room air movement, (4) radiation heat, and harmful gases (5) CO, (6) $CO_2$ that are proceeded from using the heating fuel such as oval briquettes, firewood, charcoal being used in most of the classroom, and finally (7) dust. In the standard on each factor, the next are necessary; room temperature: $16^{\circ}C{\sim}26^{\circ}C$(summer : $E.T18.9{\sim}23.8^{\circ}C$, winter: $E.T16.7{\sim}21.7^{\circ}C$), relative humidity: $30{\sim}80%$, room air movement: under 0.5m/sec, radiation heat: under $5^{\circ}C$ gap between dry-bulb temperature and wet-bulb temperature, below 1000 ppm of ca and below 10ppm of $CO_2$, dust: below 0.10 $mg/m^3$ of Volume of dust in indoor air, and ventilation standard($CO_2$) for purification of indoor air : once/6 min.(about 7 times/40 min.) in an airtight classroom. 4) In the standard on noise environment, noise level should be under 40 dB(A) and the noise measuring way and the countermeasures against it should be considered. 5) In the standard on odor environment, odor level under Physical Method should be under 2 degrees, and the inspecting way and the countermeasures against it should be considered.

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Evaluation of Abelmoschus Esculentus Seed for Antioxidant and Phytochemical Analysis Using In vitro Assays

  • Rahman, Md. Saifur;Yoo, Jin Cheol
    • 통합자연과학논문집
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    • 제7권4호
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    • pp.260-265
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    • 2014
  • The aim of this study was to assess the in vitro potential of methanolic seed extract of Abelmoschus esculentus as a natural antioxidant. The DPPH activity of the Ethyl acetate soluble fraction (10, 20, 40, 80, and $160{\mu}g/mL$) was increased in a dose dependent manner, which was found in the range of 18.97-90.47% as compared to ascorbic acid 26.44-93.71%. The $IC_{50}$ values of Ethyl acetate soluble fraction (EAES) and ascorbicacid in DPPH radical scavenging assay were obtained to be 28.12 and $18.43{\mu}g/mL$, respectively. Measurement of polyphenol content of the EAES of A. esculentus seed was achieved using Folin-Ciocalteau reagent containing 53.80 mg/g of total phenolic content, which was found signicantly higher when compared to reference standard gallic acid. Similarly total flavonoids and proabthocyanidis of EAES and chloroform soluble fraction (CAES) were found significantly 147 mg/g and 14.24 mg/g respectively when both compared to reference standard quercetin. EAES exhibited high significant lipid peroxidation inhibition effects in a dose-dependent manner, with $IC_{50}$ values of $38.08{\mu}g/mL$, whereas, standard quercetin, with $IC_{50}$ value of $36.67{\mu}g/mL$. All extract/fractions showed dose dependent reducing power ability and these differences were statistically significant (p<0.001). The results obtained in this study clearly indicate that A. esculentus seed has a signicant potential to use as a natural antioxidant agent.

육재/소다회 첨가에 따른 국내 배접지의 특성 비교 분석 (The Effect of Lye and Sodium Carbonate on the Physical Properties of Korea Lining Paper)

  • 최경화;서진호;강영석;윤경동;정소영
    • 펄프종이기술
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    • 제41권3호
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    • pp.66-70
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    • 2009
  • Paper cultural heritages usually experienced the chemical and the physical deterioration because of various factors including preservation environment and the property of their materials. General restoration technology for paper cultural heritages is the lining. The application of the lining paper and the lining technology has varied depending on researcher's experiences. Therefore, each lining material and technology must be evaluated to develop a standard guide for preservation and restoration of paper cultural heritages. To date, various analysis techniques using lining paper, in terms of their materials, have been applied to analyses of causes and condition of damages, but it is difficult to develop a standard restoration treatment method of paper cultural heritages because it varies by their material. The Hanf, is made frrr the mulberry, is generally used for the lining in Korea.edt is required that the cr, in terms properties and general properties of Hanf, is used for lining papers, are evaluated to develop a standard guide for their restoration.ed this study, the general properties of several lining papers(Hanf), especially dimensave bility, were evaluated as part of the standardization of lining papers. The result have varied depending on the pulping chemical and the manufacturers. the basis weight, thickness and tensale strength of lining papers is bigger the paper treated by natural ash than the paper treated by sodium carbonate.ed case of formation, folding endurance, and dimensave bility, the paper treated by sodium carbonate showed better properties than those of the paper treated by natural ash.

Vase Life and Quality of Cut Flower by Wet Solution according to Shipping Period and Temperature in Dendranthema grandiflorum 'Jinba'

  • Roh, Yong Seung;Kim, In Kyung;Yoo, Yong Kweon
    • 인간식물환경학회지
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    • 제22권6호
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    • pp.583-591
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    • 2019
  • This study was conducted to examine the effects of wet storage solution, transport period and temperature on vase life and quality of cut flowers in standard chrysanthemum 'Jinba'. Immediately after transport, the fresh weight and flower diameter of cut flowers did not show a difference according to wet storage solutions regardless of the transport period, but as the transport period increased, the fresh weight and flower diameter increased. The flower bud stage at harvest was maintained due to the small changes in flower diameter, and the freshness of leaves was better when transported at 5℃ than at 25℃. When transported at 25℃, the longer the transport period, the lower the quality of cut flowers as some petals opened up and showed early flowering after transport. In preservative solutions, quality of cut flowers transported at 25℃ was lower than that at 5℃ due to fresh weight and diameter according to the longer transport period. The vase life of cut flowers was 1.0 day, 0.8 day, and 7.3 days longer when transported for 3, 5, and 7 days respectively at 5℃ than at 25℃. The quality of cut flowers was better due to increase in fresh weight and flower diameter, as well as vase life in wet storage solutions of ClO2 and Chrysal OVB than in tap water, regardless of transport period and temperature. There was no difference in fresh weight and vase life between ClO2 and Chrysal OVB, but flower diameter was greater in ClO2 than in Chrysal OVB. Therefore, for long-term transport of cut standard chrysanthemum 'Jinba', wet storage transport in ClO2 at 5℃ was found effective in maintaining the quality and vase life of cut flowers.

수학과의 새로운 교육과정 모형 (New Curriculum Models for Mathematics Department in Korean College)

  • 이춘호;이상구;윤석봉
    • 한국수학교육학회지시리즈E:수학교육논문집
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    • 제19권4호
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    • pp.671-682
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    • 2005
  • One of the main function of the university is to be the center of education for the future generation. We analyze the changing standard of mathematics curriculums in Korean colleges and introduce new curriculum models in our changing social and educational environment.

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자착형 방수시트의 성능 품질기준 개선안에 관한 연구 (A Research on Improvement Scheme for Performance Quality Standard of Self-Adhesive Waterproofing Sheet)

  • 전종수;박완구;김윤호;박진상;송제영;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2012년도 추계 학술논문 발표대회
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    • pp.261-262
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    • 2012
  • The field application through the quality control of self adhesive rubberized asphalt waterproofing sheet was regulated by KS F 4934 of Korea Standard in 2003. However, regulations that different material properties of self-Adhesive waterproofing sheets are difficult on the standard. Therefore, this research was performed for of quality control all affiliations of self-adhesive waterproofing sheet through basic properties test and proposed quality standard revised bill in KS F 4934.

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A Simple Method for Generation of Homologous Internal Standards for Competitive PCR

  • Choi, Eu-Na;Hahn, Sung-Sik;Choi, Kyung-Hee;Na, Doe-Sun
    • BMB Reports
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    • 제29권5호
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    • pp.481-483
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    • 1996
  • In competitive PCR, which is used to quantify target DNA an internal standard is needed. Here we present a simple method to construct homologous competitive standards. The method, which is based upon deletion of a portion of the target DNA, does not require any additional primers. This is the simplest method developed thus far to construct a competitive standard. The whole procedure. from construction of a competitive standard to quantitation by PCR, can be completed within a single day.

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