• Title/Summary/Keyword: 열 시뮬레이션

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Experimental Studies for Solar Drying System of Agricultural Products(II) - Solar drying characteristics for rough rice - (태양열 건조 시스템에 관한 실험적 연구(II) - 벼의 태양열 건조 특성 -)

  • Koh, Hak-Kyun;Kim, Yong-Hyeon;Song, Dae-Bin;Park, Jae-Bok
    • Solar Energy
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    • v.11 no.3
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    • pp.21-30
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    • 1991
  • In-bin grain drying experiments were performed to investigate the drying characteristics between natural air and solar heated-air drying system of rough rice. A computer simulation model for solar drying system of rough rice resulted in a good agreement between the experimental and predicted moisture content. In order to save the electric energy consumption of fan, airflow rates control system using inverter was developed and resulted in the effect of energy saving.

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Comparative Analysis of Prediction Performance of Aperiodic Time Series Data using LSTM and Bi-LSTM (LSTM과 Bi-LSTM을 사용한 비주기성 시계열 데이터 예측 성능 비교 분석)

  • Ju-Hyung Lee;Jun-Ki Hong
    • The Journal of Bigdata
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    • v.7 no.2
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    • pp.217-224
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    • 2022
  • Since online shopping has become common, people can easily buy fashion goods anytime, anywhere. Therefore, consumers quickly respond to various environmental variables such as weather and sales prices. Therefore, utilizing big data for efficient inventory management has become very important in the fashion industry. In this paper, the changes in sales volume of fashion goods due to changes in temperature is analyzed via the proposed big data analysis algorithm by utilizing actual big data from Korean fashion company 'A'. According to the simulation results, it was confirmed that Bidirectional-LSTM(Bi-LSTM) compared to LSTM(Long Short-Term Memory) takes more simulation time about more than 50%, but the prediction accuracy of non-periodic time series data such as clothing product sales data is the same.

COB, COH Package LED Module Thermal Analysis Simulation (COB, COH Package LED Module 열 해석 시뮬레이션)

  • Choi, Keum-Yeon;Eo, Ik-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.11
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    • pp.5117-5122
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    • 2011
  • In this paper, thermal analysis simulation program by taking advantage of COMSOL Multiphysics, LED Module for the production of the most preferred package type, omitting the COH Type COB Type and board simulation of the thermal analysis is in progress. LED Module that passes through the Heat-sink of the simulation results, depending on the location of the COB Type Max. Approximately $78^{\circ}C$ ~ Min. Approximately $62^{\circ}C$, COH Type the Max. Approximately $88^{\circ}C$ ~ Min. Approximately $67^{\circ}C$ has been confirmed that the temperature stability. Compared with COB Type Max. AIthough temperature difference is about $10^{\circ}C$, Min. At a temperature of about $5^{\circ}C$ confirmed to be enough to reduce the gap, LED Point confirming the results of the temperature curves for COB Type Max. Approximately $100^{\circ}C$ ~ Min. Approximately $77^{\circ}C$, COH Type the Max. Approximately $100^{\circ}C$ ~ Min. Approximately $86^{\circ}C$ temperature stability was confirmed that, COB Type COH Type, compared to approximately $10^{\circ}C$ temperature was higher.

A Study on the Network Design in District Heating Networks : Focused on Critical Link (집단에너지 네트워크 설계에 관한 연구 : 크리티컬 링크를 중심으로)

  • Song, Sang Hwa;Lim, Ok-Kyung;Lee, Jae-Seung;Kim, Hyun-Chul;Ahn, Chang-Koo
    • Journal of Energy Engineering
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    • v.26 no.3
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    • pp.123-130
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    • 2017
  • The district heating system has been successfully implemented with higher efficiency levels of energy production and reduction of carbon emissions during heat generation. Traditionally the system consisted of small number of production and demand sites, but, recently it has evolved into a network with large number of sites interconnected each other. By connecting multiple sites into a network, heat from low-cost production sites can be supplied to distant demand sites so as to lower the total operation cost. In this study, we simulate and analyze distict heating networks focused on critical links. a critical link is defined as a link in which capacity is fully utilized. If a newtork has critical links, then those cricial links become bottlenecks and it is difficult to improve the overall network efficiency.

A performance simulation of heat pump system for heating and cooling (냉난방 열펌프시스템의 성능시뮬레이션)

  • 강호철;김영복;김성태;민영봉
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1999.07a
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    • pp.104-111
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    • 1999
  • 증기압축식 열펌프시스템은 그림 1에 나타난 바와 같이 증발기에서의 흡열과 응축기의 방열을 냉난방에 이용할 수 있으며, 공기를 열원으로 할 때는 공기 중 저밀도의 에너지를 고밀도의 에너지로 전환하여 이용할 수 있으며 지중 온도의 연중변화가 적은 점을 이용하여 지열을 열원으로 할 때는 공기를 열원으로 할 경우에 필요한 제상 장치(defrost cycle)가 필요 없게 되고, 압축기 부하도 줄어들게 되어 열펌프 수명이 길어지게 되며 경제성을 확보할 수 있을 것으로 기대된다. (중략)

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A Simultaneous Test of Unit Root and Level Change (단위근과 수준변화에 대한 동시가설 검정)

  • Jeon, Deok-Bin;Park, Dae-Geun
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2005.05a
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    • pp.806-813
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    • 2005
  • 시계열의 구조를 정확히 파악하기 위해서는 구조변화와 단위근의 존재여부를 가설 검정하는 것이 필요하다. 하지만, 이 두 가지의 가설들은 각각 검정되어 왔고, 이에 따라 단위근도 존재하고 구조변화도 존재하거나, 어느 하나만 존재하는 시계열들을 구분하여 파악하는 데에 있어서는 한계점이 있었다. 이 논문에서는 상태공간모형과 시뮬레이션 방법에 근거하여 두 가지 가설을 동시에 검정하는 절차를 제시하여 논란이 되는 시계열들에 대해 합리적인 해결책을 제시하고자 한다.

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