• Title/Summary/Keyword: Energy Balance Analysis

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A Study on Analysis of Eco-space from a Standpoint of Poong-soo -On the Ground of Korean Traditional Poong-soo- (풍수지리관점(風水地理觀點)에서 본 생태공간해석(生態空間解析)에 관한 연구(硏究) -한국(韓國)의 전통적(傳統的) 풍수지리(風水地理)를 중심(中心)으로-)

  • Hyun, Young Jo;Lee, Dong Kun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.5 no.6
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    • pp.49-63
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    • 2002
  • While the existing feng-shui is largely approached architecturally and geographically as positive place and negative place, the study is characterized by approaching and analyzing poong-soo environmentally. The theory of Eco-city as one of modern-city theories is worthy of studying by analyzing the merits and demerits of it and combining it with poong-soo and making a new alternative theory. Theory of Natural Energy and principle of Natural Balance. Thus, poong-soo ideas can be an important view of nature in analyzing the theory of Eco-city which is coming to the front these days. In particular, we try to make use of poong-soo as a basic theory for a city planning and design by studying and analyzing and combining the merits and demerits of Eco-city with poong-soo and presenting a new alternative method of a stable and balanced "refined city development". On the other hand, we connect 'theory with practice(or experience)' by covering all spaces variably from minimum unit space to city-space from the standpoint of poong-soo. But, problem of the Theory of Eco-city from the view of poong-soo are too artificial and theoretical, even if ideal. Conversely, from the view of Eco-city, the possibility of the practicability of Korean poong-soo is judged to be high. we can tell that among capital cities applied by poong-soo, historical cities like Beijing in China, Seoul in Korea and Tokyo in Japan are poong-soo cities in accordance with the requirements of Eco-city.

A Characteristics of the Applied SOG Lens for the CPV Module (SOG렌즈를 적용한 집광형 태양전지모듈 특성)

  • Jeong, Byeong-Ho;Lee, Kang-Yoen;Park, Ju-Hoon;Moon, Eun-Ah;Lee, Sang-Hyun;Kim, Dae-Gon
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.61 no.2
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    • pp.97-102
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    • 2012
  • CPV system in the desert areas or areas near the equator, as is suitable for high-temperature region. As compared to silicon solar cells, CPV system have a high proportion of a BOS (balance of system). Solar cells because of its low proportion when designing a module technology is applied in a variety of ways. Applied to the CPV system is classified into two kinds of optical technology. One of those using fresnel lens uses refraction of light energy. The other is a mirror reflection of the structure using sprays. Both of these two ways to condense the sun to collect solar cell is a form of light. And goals by using a small solar cell materials is to produce more energy. In this paper, suitable for a domestic environment, with the aim CPV Manufacturing Technology, built on a variety of modular process technology to the development of a prototype performance analysis was carried out. In particular, silicone coated on the glass by the method of implementation of the Fresnel lens SOG(Silicon on glass) by applying the lens to absorb the solar spectrum was broad. In addition to, for the analyze to characteristics of the CPV module, developed CPV module performance and generating characteristics studied. These related technology through research and development of high-performance multi-junction solar cells, modules, development of concentrating solar power systems to facilitate the growth of the market is considered to be.

Analysis on a Dynamic Model with One Dimension in Water Transportation of PEM Fuel Cell (PEM연료전지의 수분전달에 있어서 1차원 해석을 수행한 동적모델에 관한 연구)

  • Bakhtiar, Agung;Hong, Boo-Pyo;You, Jin-Kwang;Kim, Young-Bok;Yoon, Jung-In;Choi, Kwang-Hwan
    • Journal of the Korean Solar Energy Society
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    • v.32 no.5
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    • pp.118-123
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    • 2012
  • Water balance has a significant impact on the overall fuel cell performance. Maintenance of proper water management should provide an adequate membrane hydration and avoidance of water flooding in the catalyst layer and gas diffusion layer. Considering the important of advanced water management in PEM fuel cell, this study proposes a simple one dimensional water transportation model of PEM fuel cell for use in a dynamic condition. The model has been created by assumption that the output is the water liquid saturation difference. The liquid saturation change is the total difference between the additional water and the removal water on the system. The water addition is obtained from fuel cell reaction and the electro osmotic drag. The water removal is obtained from capillary transport and evaporation process. The result shows that the capillary water transport of low temperature fuel cell is high because the evaporation rate is low.

Association Analysis between SNP Marker in Neuopeptide Y (NPY) Gene and Carcass and Meat Quality Traits in Korean Cattle

  • Chung, Eui-Ryong;Shin, Sung-Chul;Heo, Jae-Pil
    • Food Science of Animal Resources
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    • v.31 no.4
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    • pp.537-542
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    • 2011
  • Biological or physiological genes that regulate metabolism and energy partitioning have the potential to influence economically important traits such as carcass and meat quality traits in beef cattle. The neuropeptide Y (NPY) functions as a central appetite stimulator and plays a major role in feed intake and energy-balance control. Therefore, the NPY gene is an excellent biological and physiological candidate gene for body weight, feeding, fatness or growth related traits in beef cattle. The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the NPY gene and to evaluate the association of NPY SNP markers with carcass and meat quality traits in Korean cattle. The genomic region (711 bp) including intron 2 of NPY gene was amplified and sequenced, and five SNPs, g.4389 Del(C), g.4371Del(C), g.4271T>C, g.1899A>G and g.1517A>C, were identified. The PCR-RFLP method was then developed to genotype the individuals examined. The g.4271T>C SNP was significantly associated with M. Longissimus dori area (LDA) value (p<0.027). Animals with the TT ($78.144{\pm}0.950\;cm^2$) genotype had higher LDA than those with the CC ($72.266{\pm}2.039\;cm^2$), and animals with TC genotype showed intermediate value. This SNP genotype also showed a highly significant additive genetic effect for the LDA (p<0.01). No significant associations, however, was detected between any of the SNP genotype and other carcass traits measured in this study. In conclusion, SNP genotype of the NPY gene may be used as DNA markers to select animals that have a higher meat yield.

A Study on the Control of the Temperature and Relative Humidity in Greenhouse by Adjusting the Amount of Natural Ventilation and Fog Spray Quantity (자연환기량과 포그분무량 조절에 의한 온실 온습도의 동시제어 기법 연구)

  • Kim, Youngbok;Sung, Hyunsoo;Hwang, Seungjae;Kim, Hyeontae;Ryu, Chanseok
    • Journal of the Korean Solar Energy Society
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    • v.36 no.5
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    • pp.31-50
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    • 2016
  • To develope a greenhouse fog cooling system to control the temperature and relative humidity simultaneously to the target value, a theoretical analysis and experiments were done. The control process includes the measuring of environmental variables, setting and coding of the water and heat balance equations to maintain the target temperature and relative humidity in greenhouse, calculating of the open level of the greenhouse roof window that governs the natural ventilation and spray water quantity, and operating of the motor to open/close the roof window and pump to spray for water. The study results were shown to be very good because the average air temperature in the greenhouse was kept to be about $28.2^{\circ}C$ with the standard deviation of about $0.37^{\circ}C$ compared to the target temperature of $28^{\circ}C$ and the average relative humidity was about 75.2% compared to the target relative humidity was 75% during the experiments. The average outside relative humidity was about 41.0% and the average outside temperature was $27.2^{\circ}C$ with the standard deviation of about $0.54^{\circ}C$. The average solar intensity in the greenhouse was 712.9 W. The wind velocity of outside greenhouse was 0.558 m/s with the standard deviation of 0.46 m/s.

Comparative Analysis and Evaluation of Dietary Intake of Koreans by Age Groups : (4) The Korean Diet Quality Index (서울 및 근교에 거주하는 한국인의 연령별 식생활 비교 및 평가: (4) 식사의 질 평가)

  • 심재은;백희영;이심열;문현경;김영옥
    • Journal of Nutrition and Health
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    • v.35 no.5
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    • pp.558-570
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    • 2002
  • This study was performed to develop an index assessing the overall diet quality for Korean. The study subjects consisted of preschool children (PC), elementary school children (EC), high school students (HS), college students (CS), and adults over 30 years old living Seoul and the surrounding areas. The subjects over 30 years old were classified to 30-49 years, 50-69 years, and over 70 years. A dietary survey was conducted using 24-hour recall method and data were collected from 2392 people. Newly developed Korean diet quality index (KDQI) was an index assessing the overall diet quality from the view point of balance. KDQI was based on the nutritional problems of Koreans, dietary risk factors for chronic degenerative diseases, 5 major food groups, and dietary guidelines. The ten components of KDQI were vegetables, fruits, dairy products, dietary variety score, calcium intake, iron intake, energy intake, fat intake, and cholesterol intake. The full score of each component was 10 points and the score of KDQI was calculated by summing the scores of the 10 components. When the KDQI was applied to this study subjects, the distribution of subjects KDQI scores was similar to normal distribution. Mean score of KDQI was 56.0 and the range of the mean by age was from 45.7 for the subjects over 70 years old to 60.7 for the elementary school children. The components which composed the lowest three means were dairy intake, fruit intake, Ca intake in most age groups. Mean score of DVS was one of the highest three but not for the subjects over 50 years old. After subjects with KDQI score over 70 were classified to higher poop and those with KDQI score under 40, to lower group, nutritional characteristics were compared. Energy contributions of carbohydrate, proteins, and fit, percentages of RDA for major nutrients, and dietary diversity scores were more adequate in the higher poop than in the lower group. The lower poop had more risks for chronic degenerative diseases. According to the results, KDQI was valid index to assess the overall diet quality and it could be used to detect risk group for malnutrition and chronic degenerative diseases.

Analysis of the Hydraulic Behaviour in the Nearshore Zone by a Numerical Model (수치모형에 의한 연안해역 해수운동의 분석)

  • Lee, Hee-Young;Jeoung, Sun-Kil
    • Water for future
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    • v.27 no.2
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    • pp.73-83
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    • 1994
  • The unproper development of the nearshore zone can enhance the diffusion of pollutant in the nearshore zone resulting in unbalanced sediment budget of beach which causes alteration of beach topography. Therefore, it is required to predict the effects of the envirnmental change quantitatively. In this paper, the depth-averaged and time-averaged energy balance equation is selected to acount for the wave transformation such as refraction, shoaling effect, the surf zone energy disipation, wave breaking index and bore, due to wave breaking in the shore region.(Numerical solutions are obtained by a finite difference method, ADI and Upwind. For the calculation of the wave-induced current, the unsteady nonlinear depth-averaged and time-averaged governing equation is derived based on the continuity and momentum equation for imcompressible fluid.) Numerical solutions are obtained by finite difference method considering influences of factors such as lateral mixing coefficient, bed shear stress, wave direction angle, wave steepness, wave period and bottom slope. The model is applied to the computation of wave transformation, wave-induced current and variation of mean water leel on a uniformly sloping beach.

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Regional Groundwater Flow Characteristics due to the Subway System in Seoul, Korea (지하철에 의한 서울특별시 광역 지하수 유동 특성)

  • Shin, Esther;Kim, Hyoung-Soo;Ha, Kyoochul;Yoon, Heesung;Lee, Eunhee
    • Journal of Soil and Groundwater Environment
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    • v.20 no.3
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    • pp.41-50
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    • 2015
  • Hydrogeologic environment of the Mega City such as Seoul, suffers from rapid changes caused by urbanization, construction of underground subway or buildings, and contaminant loading by diverse anthropogenic activities. Understanding the present condition of groundwater environment and water budget is necessary to prevent natural and manmade disasters and to prepare for sustainable water resource management of urban environment. In this study, regional groundwater flow and water budget status of Seoul was analyzed using numerical simulation. Modeling result indicated that groundwater level distribution of Seoul generally followed the topography, but the significant decreases in groundwater level were observed around the subway network. Steady-state water balance analysis showed groundwater recharge by rainfall and leakage from the water supply network was about 550,495 m3/day. Surface water inflow and baseflow rate via Han River and major streams accounted for 799,689 m3/day and 1,103,906 m3/day, respectively. Groundwater usage was 60,945 m3/day, and the total groundwater leakage along the subway lines amounted to 114,746 m3/day. Modeling results revealed that the subway could decrease net groundwater baseflow by 40%. Our study result demonstrated that the subway system can have a significant influence on the groundwater environment of Seoul.

Influences of Urban Trees on the Control of the Temperature (도시의 수목이 기온의 조절에 미치는 영향)

  • 김수봉;김해동
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.3
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    • pp.25-34
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    • 2002
  • The purpose of this paper is to discuss the function of microclimate amelioration of urban trees regarding the environmental benefits of street trees in summer, focusing on the heat pollution-urban heat island, tropical climate day's phenomenon and air pollution. We measured the diurnal variation of air/ground temperatures and humidity within the vegetation canopy with the meteorological tower observation system. Summertime air temperatures within the vegetation canopy layer were 1-2$^{\circ}C$ cooler than in places with no vegetation. Due to lack of evaporation, the ground surface temperatures of footpaths were, at a midafternoon maximum, 8$^{\circ}C$ hotter than those under trees. This means that heat flows from a place with no vegetation to a vegetation canopy layer during the daytime. The heat is consumed as a evaporation latent heat. These results suggest that the extension of vegetation canopy bring about a more pleasant urban climate. Diurnal variation of air/ground temperatures and humidity within the vegetation canopy were measured with the meteorological tower observation system. According to the findings, summertime air temperatures under a vegetation canopy layer were 1-2$^{\circ}C$ cooler than places with no vegetation. Due mainly to lack of evaporation the ground surface temperature of footpaths were up to 8$^{\circ}C$ hotter than under trees during mid-afternoon. This means that heat flows from a place where there is no vegetation to another place where there is a vegetation canopy layer during the daytime. Through the energy redistribution analysis, we ascertain that the major part of solar radiation reaching the vegetation cover is consumed as a evaporation latent heat. This result suggests that the expansion of vegetation cover creates a more pleasant urban climate through the cooling effect in summer. Vegetation plays an important role because of its special properties with energy balance. Depended on their evapotranspiration, vegetation cover and water surfaces diminish the peaks of temperature during the day. The skill to make the best use of the vegetation effect in urban areas is a very important planning device to optimize urban climate. Numerical simulation study to examine the vegetation effects on urban climate will be published in our next research paper.

Computer Simulation for Smelting Tretment of Waste Casting Sand (폐주물사의 용융처리에 관한 Computer Simulation)

  • Chung, Won-Sub;Min, Dong-Jun;Kim, Yong-Ha
    • Resources Recycling
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    • v.5 no.3
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    • pp.24-30
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    • 1996
  • The computcr s~mulatiun model in vanaus s~nelllng process for melling waste cashhg sand was developed by using energy and malcrial balance concept. This modcl can prcdict the coal, flux and oxygen conaumptron and thc volume and temperature of off-gas The ~niljor critical varlablcs for smclting process can be crplained by using the analysis of energy and malc~ialb alance. Thc Innst lmportarlt variables lor smelting process were h i ~ hpo st-combust~anr atla, high heat transfer crficiency and refractory pratcclion lechnalogy. For saving encrg), in this smelting proccss, selection of caw marerials i.e coal, flus was important, cspacially ubi~go f low volatile coal was prufitahle.

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