• 제목/요약/키워드: energy budget

검색결과 251건 처리시간 0.024초

Comparison of Daily Soil Water Contents Obtained by Energy Balance-Water Budget Approach and TDR

  • Rim, Chang-Soo
    • Korean Journal of Hydrosciences
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    • 제8권
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    • pp.57-68
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    • 1997
  • The daily soil water contents were obtained from the time domain reflectometry(TDR) method and energy balance-water budget approach with eddy correlation at the two small semiarid watersheds of Lucky Hills and Kendall during the summer rainy period. There was a comaprison of daily soil water content measured and estimated from these two different approaches. The comparison is valuable to evaluate the accuracy of current soil water content measuring system using TDR and energy balance-water budget approach using eddy correlation method at a small watershed scale. The degree of simiarity between the regressions of these two methods of measuring soil water content was explained by determining the correlations between these methods. Simple linear regression analyses showed that soil water content measured from TDR method was responsible for 58% and 63% of the variations estimated from energy balance-water budget approach with edy correlation at Lucky Hills and Kendall, respectively. The scatter plots and the regression analyses revealed that two different approaches for soil water content measurement at a small watershed scale have no significant difference.

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스노우팩-융설 계산을 위한 에너지수지 알고리즘 (An Energy Budget Algorithm for a Snowpack-Snowmelt Calculation)

  • 이정훈;고경석
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제16권5호
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    • pp.82-89
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    • 2011
  • Understanding snowmelt movement to the watershed is crucial for both climate change and hydrological studies because the snowmelt is a significant component of groundwater and surface runoff in temperature area. In this work, a new energy balance budget algorithm has been developed for melting snow from a snowpack at the Central Sierra Snow Laboratory (CSSL) in California, US. Using two sets of experiments, artificial rain-on-snow experiments and observations of diel variations, carried out in the winter of 2002 and 2003, we investigate how to calculate the amount of snowmelt from the snowpack using radiation energy and air temperature. To address the effect of air temperature, we calculate the integrated daily solar radiation energy input, and the integrated discharge of snowmelt under the snowpack and the energy required to generate such an amount of meltwater. The difference between the two is the excess (or deficit) energy input and we compare this energy to the average daily temperature. The resulting empirical relationship is used to calculate the instantaneous snowmelt rate in the model used by Lee et al. (2008a; 2010), in addition to the net-short radiation. If for a given 10 minute interval, the energy obtained by the melt calculation is negative, then no melt is generated. The input energy from the sun is considered to be used to increase the temperature of the snowpack. Positive energy is used for melting snow for the 10-minute interval. Using this energy budget algorithm, we optimize the intrinsic permeability of the snowpack for the two sets of experiments using one-dimensional water percolation model, which are $52.5{\times}10^{-10}m^2$ and $75{\times}10^{-10}m^2$ for the artificial rain-on-snow experiments and observations of diel variation, respectively.

가시배새우(Lebbeus groenlandicus)의 유생 단계 에너지수지 (Energy Budget of Spiny Lebbeid Shrimp Lebbeus groenlandicus Larvae)

  • 김원기;권오남;박기영
    • 한국수산과학회지
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    • 제46권6호
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    • pp.801-806
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    • 2013
  • Spiny lebbeid shrimp Lebbeus groenlandicus larvae were reared in the laboratory to estimate the energy budget from the zoeal to the post-larval stage. Energy expended by larvae on growth and respiration was determined from values for feeding, growth, molting, and metabolism. We calculated that 16.22 J were used for growth throughout all larval stages. Energy loss during molting was estimated as 1.03 J, and energy used for respiration was estimated as 1.31 J. Energy taken in by feeding was estimated as 77.16 J, while the sum of energies expended in excretion and egestion was 58.61 J. Larvae were estimated to assimilate 24.6% of ingested food as energy and to use ~85% of the assimilated energy for somatic growth. Gross growth efficiency ($K_1$) and net growth efficiency ($K_2$) were shown to be ~22% and 93%, respectively. Maintenance costs of respiration were estimated as ~9.7% of assimilated energy.

WISE 관측자료를 이용한 수도권지역의 복사에너지수지 분석 (Analysis of Radiation Energy Budget Using WISE Observation Data on the Seoul Metropolitan Area)

  • 지준범;이한경;민재식;채정훈;김상일
    • 한국태양에너지학회 논문집
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    • 제37권6호
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    • pp.103-114
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    • 2017
  • Radiation energy budget was analyzed using observation data from the Weather Information Service Engine (WISE) energy flux tower on the Seoul metropolitan area. Among observation data from the 13 energy flux towers, we used meteorological variables, radiation data (upward and downward short wave, upward and downward long wave, net short wave, net long wave and net radiation), albedo and emissivity for 15 months from July 2016 to September 2017. Although Gajwa (205) and Ttuksumm (216) sites located in urban, the albedo was relatively high due to the surround environment by glass wall buildings and the Han river around the sites. And Bucheon (209) site located in the suburb represented generally low emissivity. As a result, the albedo decreased and the emissivity increased in the city center. In the Seoul metropolitan area, the net radiation energy is $73.9W/m^2$ that the radiation budget of the surface is absorbed into the atmosphere. According to WISE observation data, it can be seen that observation at each sites are influenced by the surrounding environment.

Adaptive Filtering Scheme for Defense of Energy Consumption Attacks against Wireless Computing Devices

  • Lee, Wan Yeon
    • International journal of advanced smart convergence
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    • 제7권3호
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    • pp.101-109
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    • 2018
  • In this paper, we propose an adaptive filtering scheme of connection requests for the defense of malicious energy consumption attacks against wireless computing devices with limited energy budget. The energy consumption attack tries to consume the battery energy of a wireless device with repeated connection requests and shut down the wireless device by exhausting its energy budget. The proposed scheme blocks a connection request of the energy consumption attack in the middle, if the same connection request is repeated and its request result is failed continuously. In order to avoid the blocking of innocuous mistakes of normal users, the scheme gives another chance to allow connection request after a fixed blocking time. The scheme changes the blocking time adaptively by comparing the message arriving ate during non-blocking period and that during blocking period. Evaluation shows that the proposed defense scheme saves up to 94% energy consumption compared to the non-defense case.

육상어류양식장 고형오물을 공급한 해삼(Apostichopus japonicus)의 성장과 에너지 수지 (Effect of Fish Farm Fecal Solid Diets on the Growth and Energy Budget of Juvenile Sea Cucumber Apostichopus japonicus)

  • ;정우철;최종국;;김경덕;최병대;강석중
    • 한국수산과학회지
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    • 제49권2호
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    • pp.168-175
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    • 2016
  • We conducted a 90-day feeding experiment to evaluate the growth and energy budget of the sea cucumber Apostichopus japonicus. Sea cucumbers with a mean initial wet body weight of 3.03±0.06 g were fed one of the following three diets: an eel fecal solid diet, rainbow trout fecal solid diet, or a commercial diet at a water temperature of 17±1℃ and salinity of 32±1 psu. The results suggested that the diets affected the final body weight, specific growth rate (SGR), food ingestion, feces production ratio, and hence the growth and energy budget of the sea cucumbers. Sea cucumbers fed the eel and rainbow trout fecal solid diets showed poorer energy absorption, assimilation, and growth than those fed the commercial diet. The sea cucumbers fed the commercial diet had a significantly higher SGR and proportion of energy used for growth than those fed the other two diets. Sea cucumbers fed the rainbow trout fecal solid diet showed a comparatively higher ingestion rate and feces production ratio than those fed the commercial diet. The eel and rainbow trout fecal solid diets, therefore, were not suitable for sea cucumbers in intensive cultivation. Our findings will facilitate further development of more appropriate diets for culture of sea cucumber.

먹이에 따른 물가자미 (Eopsetta grigorjewi) 치어의 에너지 수지 (Energy Budget of Snotted Halibut Juvenile, Eopsetta griorjewi with Two Different Prey Items)

  • 이선식;한경남;윤원득
    • 한국수산과학회지
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    • 제36권4호
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    • pp.358-364
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    • 2003
  • Gross energy intake fecal, nitrogen excretory and metabolized energy of snotted halibut juvenile, Eopsetta grigorjewi, fed on Tigriopus iaponicus (Group A) and the enriched Artemia nauplii (Group B), were quantitatively investigated and represented as balance equations of energy and material. Absorption efficiency (AE), gross conversion efficiency $(K_1)$ and net conversion efnciency $(K_2)$ were also estimated to understand the changes in efficiency by the prey Gross energy intake, fecal, nitrogen excretory, metabolized and growth energy of Group A were $2.790\pm0.247,\;0.495\pm0.046,\;0.018\pm0.003,\;0.214\pm0.047\;cal\;mg^{-1}\;day^{-1}$ and $2.063\;cal\;mg^{-1}\;day^{-1},$ respectively. The same parameters of Group B were $4.801\pm0.165,\;0.579\pm0.031,\;0.055\pm0.010,\;0.306\pm0.048\;cal\;mg^{-1}\;day^{-1}$ and $3.861\;cal\;mg^{-1}\;day^{-1},$ respectively. Energy budget of Group A and B were represented as 100 C= 7.67 M+17.7 F+0.65 U+73.94 G and 100C=6.37 M+ 12.1 F+1.15 U+80.42 G, respectively, where C, M, F, U, and G represent gross energy intake, metabolized energy, fecal energy, nitrogen excretory (non-fecal) energy and growth energy, respectively. AEs of Croup A and B were $81.52\pm1.89,\;86.79\pm0.70\%,$ respectively, with significant difference at p=0.01 level. However, $K_1\;and K_2$ of Group A and B showed no significant difference at p=0.01 level, with $74.21\pm6.57,\;80.48\pm2.76\%\;and\;91.17\pm7.26,\;92.74\pm2.69\%$ respectively. These results suggest that T. japonicus is a possible substitute for Artemia nauplii for the snotted halibut juvenile.

Research and Development of Polymer Electrolyte Fuel Cells in Japan

  • Miyata, Seizo
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.60-61
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    • 2006
  • New Energy and Industrial Technology Development Organization (NEDO) promotes R&D that individual private sector enterprises can not undertake by themselves. To do this, it utilizes an extensive network that supports cooperation between industries, universities, and public research organizations. NEDO's government-funded R&D budget for FY2005 totals approximately 148.8 billion yen. Fuel cells and hydrogen technology development project is one of NEDO's emphasizing projects. The budget size was ${\yen}$20.8 billion, corresponding to about 60% of annual expenditure of Japanese government for fuel cells in FY2005. These projects consist of 8 programs as follows.

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수온과 먹이에 따른 도루묵 (Arctoscopus japonicus) 치어의 에너지수지 (Energy budget of sandfish juvenile, Arctoscopus japonicus reared at different diet conditions and water temperature)

  • 양재형;이성일;윤상철;김종빈;전영열;박기영
    • 수산해양기술연구
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    • 제47권2호
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    • pp.128-138
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    • 2011
  • In this study, energy budget was estimated to produce an efficient artificial seed. And it needs to enhance fisheries productivity of sandfish, A. japonicus. In order to estimate energy budget of the sandfish, A. japonicus juvenile fed on nonriched Artemia nauplii (NA) and the enriched Artemia nauplii (EA), of sandfish were reared at constant condition of seawater temperature of natural temperature (NT) and heated temperature (HT). During the reared period, energy used by the reared juveniles were calculated from estimates of data on ingestion, growth, oxygen consumption, nitrogen excretion and energy content. Energy budget of NT-NA, NT-EA, HT-NA and HT-EA were represented as 100C=66.49G+21.28M+0.78F+1.44U, 100C=67.54G+21.40M+9.39F+1.67U, 100C=66.86G+22.66M+8.01F+2.47U and 100C=67.06G+22.96M+7.70F+2.28U. The assimilation efficiency estimated NT-NA, NT-EA, HT-NA and HTEA were represented as 87.78%, 88.94%, 89.52% and 90.02%. Gross growth efficiency estimated NT-NA, NT-EA, HT-NA and HT-EA were represented as 66.49%, 67.54%, 66.86% and 67.06%. Net growth efficiency estimated NT-NA, NT-EA, HT-NA and HT-EA were represented as 75.75%, 75.94%, 74.68% and 74.49%. In this results, two ways could be considered to produce an efficient artificial seed of sandfish. To hasten the growth of sandfish juvenile, heated seawater (HT) and enriched Artemia nauplii (EA) should be inputted to reared condition. And to increase the energy efficiency, natural seawater (NT) and enriched Artemia nauplii (EA) should be inputted to reared condition.

수소.연료전지 연구개발 투자현황 분석 (Analysis of R&D Investment for Hydrogen and Fuel Cell)

  • 박노언;김형욱
    • 한국수소및신에너지학회논문집
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    • 제21권2호
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    • pp.143-148
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    • 2010
  • Research and Development (R&D) investment of hydrogen and fuel cell, funded by government from 2007 to 2008 in Korea, has been analyzed. R&D investment of hydrogen and fuel cell in 2008 would see 9% and 29% of total budget in the field of renewable energy, respectively. It was found that R&D investment is mainly dependent on mission of Ministry in Korea. Basic and apply research would be mainly invested by Ministry of Education, Science and Technology (MEST), while development research would be conducted by Ministry of Knowledge Economy (MKE). In R&D investment by performer, hydrogen technology would be conducted by government-funded institute and university. It was also shown that funds for hydrogen production have been much supported than hydrogen storage. Meanwhile, fuel cell would be mainly conducted by major companies. It was also shown that funds for proton exchange membrane fuel cell (PEMFC) have been much invested than other technology in fuel cell.