• Title/Summary/Keyword: exchange spring

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Energy Saving Effect of ERV(Energy Recovery Ventilator) with Economizer Cycle - Focused on the School Buildings - (Economizer cycle을 채용한 전열교환형 환기시스템의 에너지 절감 효과 분석 -국내 학교를 대상으로-)

  • Kim, Joo-Wook;Park, Jae-Hyung;Song, Doo-Sam;Chu, Euy-Sung;Kwon, Young-Chul
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.695-700
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    • 2009
  • Maintaining an IAQ with fresh in school building is very important because the good IAQ can be possible to improve the academic performance. Since school buildings are very dense and require a lot of fresh air, the need for ERV(Energy Recovery Ventilator) has become obvious. While opening a window does provide ventilation, the building's heat and humidity will then be lost in the winter and gained in the summer, both of which are undesirable for the indoor climate and for energy efficiency. ERV technology offers an optimal solution: fresh air, better climate control and energy efficiency. However, when the outdoor air condition is favorable to control the indoor environment such as spring and autum in Korea, heat exchange in ERV would rather increase the cooling load than diminish. Economizer cycle control which using the outdoor air in controlling the indoor thermal environment has many benefit in terms of energy saving and IAQ control. In this study, the ERV with economizer cycle control will be suggested. And then the system control characteristics and energy saving effect will be analyzed through the TRSNSYS Simulation.

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Analysis on Living Factor and Present Condition of Indoor Thermal Environment in Apartment Units during Winter (아파트의 겨울철 실내온열환경 실태와 생활요인 분석)

  • Choi, Yoon-Jung;Jeong, Youn-Hong
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2008.04a
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    • pp.281-284
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    • 2008
  • The purposes of this study were to make clear the present condition of indoor thermal environment in apartment units and to analyze the relation of the living factors with indoor thermal elements. The field surveys consisted of measurements on physical elements and observations on living factors and interview on resident's subjective responses were carried out in 20 apartment units. The field surveys were carried out during the $January{\sim}March$ 2007. Measuring elements were air temperature, globe temperature, and relative humidity. As results, the averages of indoor temperature each houses were $21.2{\sim}27.2^{\circ}C$, the number of houses exceed the comfort zone were 4. The averages of globe temperature each houses were $21.3{\sim}27.5^{\circ}C$, 6 houses exceeded the comfort zone. The means of relative humidity were $19.5{\sim}58.8%$, relatively dry condition. The clothing value of residents were $0.39{\sim}0.89$ clo(average 0.68 clo). The average of thermal sensation ratings each room were $4.2{\sim}4.8$, 'neutral'$\sim$'slightly warm'. The results of regression analysis on relations of living factors with the thermal elements are as follow; ventilation time(outdoor air exchange), door opening time with balcony, and gas cooker use time had significant effect on indoor temperature.

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A study on the Typology of Malaysian Modern Housing (말레이시아 근대주거 유형에 관한 연구)

  • Ju, Seo-Ryeung;Ko, Young-Eun
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2008.04a
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    • pp.151-155
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    • 2008
  • Modernization of cities and housing in Malaysia is the history of the establishment of international trading ports due to worldwide maritime trade and exchange. In cosmopolitan cities, new housing typology appeared from the influence of various ethnic immigrants and with the fusion of traditional Malaysian housing characteristics. This study is focus on classifying the representative housing typology of Malaysia produced through the Modernizaiton of cities. Through reference review and field study, Malaysian Modern housing can be classified into 2 categories. The first one is the transformation of traditional housing. Representative typology is shophouse. Shophouses were imported from the South Coast of China and transformed into Malaysian urban housing. And the other typology is bugalow. Bugalow is the result of the fusion of traditional timber house and Western palazzo. Secondly is urban housing typology. Modern urbanization required maximum utilization of land and new typologies in the form of multi-story apartments, flats and terrace house were developed to accomodate new needs. In the sub-urban areas, the English terrace houses typology was adopted which is based on the British system of land sub-division. And nowdays luxurious housing typology, condominium is one of the popular housing for medium and high society.

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Purification and Partial Characterization of Thermostable Carboxyl Esterase from Bacillus stearothermophilus L1

  • Kim, Hyung-Kwoun;Park, Sun-Yang;Oh, Tae-Kwang
    • Journal of Microbiology and Biotechnology
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    • v.7 no.1
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    • pp.37-42
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    • 1997
  • A bacterial strain L1 producing a thermostable esterase was isolated from soil taken near a hot spring and identified as Bacillus stearothermophilus by its microbiological properties. The isolated thermostable esterase was purified by ammonium sulfate fractionation, ion .exchange and hydrophobic interaction chromatographies. The molecular weight of the purified enzyme was estimated to be 50,000 by SDS-PAGE. Its optimum temperature and pH for hydrolytic activity against PNP caprylate were $85^{\circ}C$ and 9.0, respectively. The purified enzyme was stable up to $70^{\circ}C$ and at a broad pH range of 4.0-11.5 in the presence of bovine serum albumin. The enzyme was inhibited by phenylmethylsulfonyl fluoride and diethyl p-nitrophenyl phosphate, indicating the enzyme is a serine esterase. The enzyme obeyed Michaelis-Menten kinetics in the hydrolysis of PNPEs and had maximum activity for PNP caproate ($C_6$) among PNPEs ($C_2-C_12$) tested.

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Development of Mathematical Model for Both Solute Transport in Snow and Isotopic Evolution of Snowmelt (눈 속에서의 용질이동 및 융설의 동위원소변동에 관한 모델개발)

  • Lee, Jeonghoon
    • Journal of Soil and Groundwater Environment
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    • v.17 no.5
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    • pp.31-39
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    • 2012
  • Chemical and isotopic variations of snowmelt provide important clues for understanding snowmelt processes and the timing and contribution of snowmelt to catchment or watershed in spring. The newly developed model includes a hydraulic exchange between mobile and immobile water (${\omega}$), and isotopic exchanges between both mobile water and ice ($f_1$) and immobile water and ice ($f_2$). Since the new model is based on the mobile-immobile water conceptualization, which is widely used for describing chemical tracer transport in snow, it allows simultaneous calculations of chemical as well as isotopic variations in snowpack discharge. We compare the model results with a study of solute transport and isotopic evolution of snowmelt in snow, using artificial rain-on-snow experiments with conservative anion ($Br^-$). These observations are used to test the newly developed model and to better understand physical processes in a seasonal snowpack where our model simulates the chemical and isotopic variations.

The Application of Chinese Traditional Tiger Pattern in Men's Fashion Design

  • Ji Fan
    • International Journal of Advanced Culture Technology
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    • v.11 no.1
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    • pp.253-262
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    • 2023
  • Chinese traditional patterns, which are part of our national precious heritage, have a long history. Tiger culture plays a very important role in folk art. In modern society, it is a symbol of human spirit and morality. The tiger pattern is also a unique traditional pattern in Chinese folklore. From the Spring and Autumn period to modern society, the tiger pattern has evolved in form through thousands of years of development. It is also a representative intangible cultural heritage in contemporary times. It plays a special role in the cultural exchange of different regions, resulting in the generation of the creation of folk art with great local characteristics. Therefore, traditional tiger patterns are an important part of traditional Chinese folk culture and art. In this study, by analyzing the development and evolution history of Chinese traditional tiger patterns, the application methods of Chinese traditional tiger patterns were summarized, the rich cultural connotation, artistic characteristics and application of traditional tiger pattern in modern fashion design were discussed. In contemporary design, the new and improved tiger pattern styles were explored, intangible cultural heritage was interpreted and inherited, and the cultural and artistic values contained therein were extracted. The author combined with modern fashion design, according to people's aesthetic taste and design principles, it is recreated,so that the traditional pattern has certain characteristics of The Times.But at the same time it retains its original character,and the traditional tiger pattern was inherited and the cultural connotation of clothing design was enriched.

Estimation of Air-Sea Heat Exchange Using BUOY Data at the Yellow Sea, Korea (부이 관측자료를 이용한 서해 해역의 해양-대기 열교환량 산출)

  • kang, Yune-Jeung;Hwang, Seung-On;Kim, Tae-Hee;Nam, Jae-Cheol
    • Journal of the Korean earth science society
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    • v.22 no.1
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    • pp.40-46
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    • 2001
  • Heat exchange between the atmosphere and sea is produced using the data from two 3m discus buoy installed by KMA in 1996. The meteorological and oceanic characteristics at the Dukjukdo and Chilbaldo buoy for the period 1996 ${\sim}$ 2000 are discussed. Daily averaged sensible heat and latent heat flux at each site are estimated from bulk aerodynamic method using given data and analyzed. Quantitative analyses show SST indicates 1-year cycle like air temperature but has 1 month lag. Sea level pressure is lowest in July, humidity is higher from May to August, and wind speed has averaged value of 5 m/s and higher in autumn and winter. Sensible heat flux analyses present that strong heat loss from the sea occurs in autumn and winter and weak heat loss from atmosphere appears in spring and summer, and net sensible heat loss from the sea is found throughout the year. The ocean significantly releases latent heat into atmosphere from August to May but get a little latent heat from atmosphere in other months. Net latent heat loss from the sea is larger than net sensible heat loss except in January and February. Comparison with two sites suggests that the magnitude of heat flux and their fluctuation are generally stronger at Dukjukdo than at Chilbaldo. In case study, both sensible and latent heat flux is a little more at Chilbaldo in March 1998, but substantially stronger at Dukjukdo in November 1996.

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Physicochemical Properties of Various Blends of Peatmoss and Perlite and the Selection of Rooting Media for Different Growing Seasons (다양한 종류의 피트모스와 펄라이트 혼합에 따른 물리·화학성 변화와 계절별 육묘를 위한 상토 선발)

  • Shim, Chang Yong;Kim, Chang Hyeon;Park, In Sook;Choi, Jong Myung
    • Horticultural Science & Technology
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    • v.34 no.6
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    • pp.886-897
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    • 2016
  • The physical properties of rooting media for the establishment of plugs in a greenhouse are modified according to variations in the greenhouse environment throughout the season. In this study, we established a standard for rooting media for the production of plug seedlings for each growing season (summer, winter and spring fall). Eight types of peatmoss (PM) and 4 types of perlite (PL) commonly used in Korea were collected and blended with the ratio of 7 parts PM to 3 parts PL (v/v) to make 32 different rooting media blends. We determined the total porosity (TP), container capacity (CC), air-filled porosity (AFP), pH, and electrical conductivity (EC) of the 32 media blends, and 6 media blends were selected for seasonal use. We also conducted additional analyses for plant easily available water (EAW), buffering water (BW), cation exchange capacity (CEC), and nutrient contents in the 6 media blends. The TP, CC, and AFP of the 32 media blends ranged from 64.7 to 96.0%, 42.9 to 90.1%, and 1.3 to 27.8%, respectively, indicating that the physical properties were strongly influenced by the type of PM and PL. The pH and EC of the PMs ranged from 2.96 to 3.81 and 0.08 to $0.47dS{\cdot}m^{-1}$, respectively. However, after blending the PM with the PL the pH was raised and the EC was lowered The media blends selected for the summer growing season were Blonde Golden peatmoss (BG) + No. 1 perlite size < 1 mm (PE1) and Latagro 0-10 mm (L1) + No. 2 perlite size 1-2 mm (PE2). These two media blends had 89.8-90.9% of TP, 80.8-81.3% of CC, and 9.0-9.7% of AFP. The media blends selected for the winter growing season were Sfagnumi Turvas (ST) + PE2 and Latagro 20-40 mm (L3) + PE2. These media blends had 79.9-86.7% of TP, 60.4-74.9% of CC, and 11.8-19.6% of AFP. The TP, CC, and AFP of two media blends, BG + No.3 perlite 2-5 mm (PE3) and Orange peatmoss (O) + PE3, selected for the spring and fall growing seasons, respectively, were 85.2-87.3%, 77.9%, and 7.4-9.4%, respectively. The percentage of EAW of the media blends selected for the spring, summer, and winter growing seasons ranged from 24.2-24.9%, 22.0-28.6%, and 18.0-21.8%, respectively, but the percentages of BW were not significantly different among the selected root media blends. The pH, EC, and CEC of the 6 selected media blends ranged from 3.11-3.97, $0.06-0.26dS{\cdot}m^{-1}$, and $97-119meq{\cdot}100g^{-1}$, respectively.

Estimation of the Spring and Summer Net Community Production in the Ulleung Basin using Machine Learning Methods (기계학습법을 이용한 동해 울릉분지의 봄과 여름 순군집생산 추정)

  • DOSHIK HAHM;INHEE LEE;MINKI CHOO
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.29 no.1
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    • pp.1-13
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    • 2024
  • The southwestern part of the East Sea is known to have a high primary productivity compared to those in the northern and eastern parts, which is attributed to nutrients supplies either by Tsushima Warm Current or by coastal upwelling. However, research on the biological pump in this area is limited. We developed machine learning models to estimate net community production (NCP), a measure of biological pump, with high spatial and time scales of 4 km and 8 days, respectively. The models were fed with the input parameters of sea surface temperature, chlorophyll-a, mixed layer depths, and photosynthetically active radiation and trained with observed NCP derived from high resolution measurements of surface O2/Ar. The root mean square error between the predicted values by the best performing machine model and the observed NCP was 6 mmol O2 m-2 d-1, corresponding to 15% of the average of observed NCP. The NCP in the central part of the Ulleung Basin was highest in March at 49 mmol O2 m-2 d-1 and lowest in June and July at 18 mmol O2 m-2 d-1. These seasonal variations were similar to the vertical nitrate flux based on the 3He gas exchange rate and to the particulate organic carbon flux estimated by the 234Th disequilibrium method. To expand this method, which produces NCP estimate for spring and summer, to autumn and winter, it is necessary to devise a way to correct bias in NCP by the entrainment of subsurface waters during the seasons.

Preference of Cohousing according to sense of Community (공동체의식에 따른 코하우징 선호도)

  • Kwak, Yu-Mi;Cho, Jeong-Hyun;Hong, Seo-Jung;Kwak, In-Sook;Choi, Jung-Sin
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2006.11a
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    • pp.115-122
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    • 2006
  • "Purpose of this study was to investigate influence on preference of cohousing (eg. intention to spread and intention to move in cohousing) according to sense of community by married people residing in Seoul and its outskirts. Research method used for this study was a social survey. Respondents were 214 people by accidential sampling. The collected data were analyzed by SPSS 12.0 program using frequency, mean, average, t-test, one-way ANOVA, Duncan's Multiple Range test and Multiple Regression. Findings of this study were as follows. 1) Though respondents took part in interaction meetings rarely, they took part more often in meetings for health issue, leisure and hobby. Members of meetings were mostly job colleagues. 2) The respondents were interested in meetings for exchange of used stuffs, and children and the youth program most. It was revealed that the group taking part in meetings more often have higher sense of community than others. 3) Respondents who were older, who have been living longer in the same town had higher sense of community as well as closer interaction with neighbors than others. 4) As respondents showed positive response about preference of cohousing, there was a difference between intention to spread and intention to move in cohousing. While women, more educated, less income, and higher sense of community groups showed higher intention to spread cohousing, home owner and higher sense of community groups showed higher intention to move in cohousing.

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