• 제목/요약/키워드: Thermal Response

검색결과 1,163건 처리시간 0.029초

Recognition of Material Temperature Response Using Curve Fitting and Fuzzy Neural Network

  • Ryoo, Young-Jae;Kim, Seong-Hwan;Chang, Young-Hak;Lim, Yong-Cheol;Kim, Eui-Sun;Park, Jin-Kyn
    • Transactions on Control, Automation and Systems Engineering
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    • 제3권2호
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    • pp.133-138
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    • 2001
  • This paper describes a system that can used to recognize an unknown material regardless of the change of ambient tem-perature using temperature response curve fitting and fuzzy neural network(FNN). There are some problems to realize the recogni-tion system using temperature response. It requires too many memories to store the vast temperature response data and it has to be filtered to remove noise which occurs in experiment. And the temperature response is influenced by the change of ambient tempera-ture. So, this paper proposes a practical method using curve fitting the remove above problems of memories and nose. And FNN is propose to overcome the problem caused by the change of ambient temperature. Using the FNN which is learned by temperature responses on fixed ambient temperature and known thermal conductivity, the thermal conductivity of the material can be inferred on various ambient temperature. So the material can be recognized by the thermal conductivity.

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Environmental stress-related gene expression and blood physiological responses in olive flounder (Paralichthys olivaceus) exposed to osmotic and thermal stress

  • Choi, Cheol-Young
    • Animal cells and systems
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    • 제14권1호
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    • pp.17-23
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    • 2010
  • We isolated warm temperature acclimation-related protein 65-kDa (Wap65) cDNA from the liver of olive flounder and investigated the mRNA expression of Wap65 and HSP70 in olive flounder exposed to osmotic (17.5, 8.75, and 4 psu) and thermal stress (25 and $30^{\circ}C$). The mRNA expression of Wap65 and HSP70 was increased by thermal stress. The mRNA expression of HSP70 was also increased by osmotic stress, whereas no significant change in Wap65 expression was detected. These results indicate that Wap65 mRNA expression occurs specifically in response to increases in water temperature, but not in response to osmotic stress. Plasma cortisol levels were also increased by osmotic and thermal stress. We also utilized the stress hormone cortisol to examine whether Wap65 expression is thermal-stress-specific. Cortisol treatment increased HSP70 mRNA expression in vitro, but had no significant effect on Wap65 mRNA expression. Thus, thermal stress, but not osmotic stress, induces Wap65 expression.

Study on the residual DC characteristic of Twisted Nematic liquid Crystal Display on the Polyimide Surface by the Thermal Stress (폴리이미드 표면에서의 열적 스트레스에 의한 TN셀의 잔류 DC 특성 연구)

  • Bae, Yu-Han;Kim, Sang-Hoon;Hwang, Jeoung-Yeon;Kang, Hyung-Ku;Lee, Whee-Won;Kim, Jong-Hwan;Kim, Young-Hwan;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.451-452
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    • 2005
  • In this study, the threshold voltage and the response time of thermal stressed TN-LCDs showed the same performances on none thermal stressed TN-LCDs. There was little change in TN cells. Also, while increasing thermal stress time, the transmittances of TN-LCDs on the rubbed PI surface were almost the same, But the thermal stability of TN cell was deteriorated.

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Development of Thermal-Hydro Pipe Element for Ground Heat Exchange System (지중 열교환 시스템을 위한 열-수리 파이프 요소의 개발)

  • Shin, Ho-Sung;Lee, Seung-Rae
    • Journal of the Korean Geotechnical Society
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    • 제29권8호
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    • pp.65-73
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    • 2013
  • Ground-coupled heat pump system has attracted attention as a promising renewable energy technology due to its improving energy efficiency and eco-friendly mechanism for space cooling and heating. Pipes buried in the ground play a role of direct thermal interaction between circulating fluid inside the pipe and surrounding soils in the geothermal exchange system. However, both complexities of turbulent flow coupling thermal-hydraulic phenomena and very long aspect ratio of the pipe make it difficult to model the heat exchange system directly. Energy balance for fluid flow inside the pipe was derived to model thermal-hydraulic phenomena, and one-dimensional pipe element was proposed through Galerkin formation and time integration of the equation. Developed element is combined to pre-developed FEM code for THM phenomena in porous media. Numerical results of Thermal Response Test showed that line-source model overestimates equivalent thermal conductivity of surrounding soils due to thermal interaction between adjacent pipes and finite length of the pipe. Thus, inverse analysis for the TRT simulation was conducted to present optimal transformation matrix with utmost convergence.

Thermal Wave Transfer and Combustion Response of Droplet Perturbed by Acoustic Pressure (압력파에 교란된 액적내부에서의 에너지 파동 및 반응 메커니즘)

  • Lee Cilyong;Yoon Woongsub
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 한국추진공학회 2005년도 제24회 춘계학술대회논문집
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    • pp.183-188
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    • 2005
  • This study targets to investigate thermal wave transfer in a droplet strongly coupled with acoustic pressure and its effects on combustion response. The one-dimensional vaporization model uses SRK equation of state and flash calculation method to obtain more accurate thermophysical properties and compute vapor-liquid equilibrium. Calculations of an n-pentane droplet exposed into a perturbing nitrogen gas is carried out in terms of different ambient gas pressures and wave frequencies. The thermal wave is transferred more effectively at lower frequencies, which results in the decrease in the amplitude of the response.

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EFFECTS OF AN ORIFICE-TYPE FLOW RESTRICTOR ON THE TRANSIENT THERMAL-HYDRAULIC RESPONSE OF THE SECONDARY SIDE OF A PWR STEAM GENERATOR TO A MAIN STEAM LINE BREAK (가압경수로 주증기관 파단시 증기발생기 2차측 과도 열수력 응답에 미치는 오리피스형 유량제한기의 영향)

  • Jo, J.C.;Min, B.K.
    • Journal of computational fluids engineering
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    • 제20권3호
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    • pp.87-93
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    • 2015
  • In this study, a numerical analysis was performed to simulate the thermal-hydraulic response of the secondary side of a steam generator(SG) model equipped with an orifice-type SG outlet flow restrictor to a main steam line break(MSLB) at a pressurized water reactor(PWR) plant. The SG analysis model includes the SG upper steam space and the part of the main steam pipe between the SG outlet and the broken pipe end. By comparing the numerical calculation results for the present SG model to those obtained for a simple SG model having no flow restrictor, the effects of the flow restrictor on the thermal-hydraulic response of SG to the MSLB were investigated.

A Study on the Thermal Protection Performance of Elastomeric Insulators in Different Mixing Environments (탄성내열재 배합 환경에 따른 내열 성능 변화에 관한 연구)

  • Kim, Namjo;Seo, Sangkyu;Kang, Yoongoo;Go, Cheongah
    • Journal of the Korean Society of Propulsion Engineers
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    • 제23권1호
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    • pp.108-115
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    • 2019
  • The thermal response of elastomeric insulators used as protection against high-temperature and high-pressure combustion gases varies depending on their composition and thermal environment conditions. In this paper, the thermal response characteristics of elastomeric insulators in different mixing environments were compared. Tests to determine thermal protection performance were carried out using a thermal protection rubber evaluation motor(TPREM), combustion gas velocities of 20 m/s and 100 m/s were tested at a chamber pressure of 1,000 psig. The pressure time curve of the chamber, the temperature time curve of the internal materials, the residual thickness and the thermal destruction depth of the test specimens were obtained. The results showed that the thermal protection performance of elastomeric insulators in different mixing environments was similar.

Thermal Conductivity from an in-situ Thermal Response Test Compared with Soil and Rock Specimens under Groundwater-bearing Conditions (지하수 부존지역에서의 토질 및 암석 시료와 현장 열응답시험의 열전도도 비교)

  • Kim, Jin-Sung;Song, Sung-Ho;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • 제23권4호
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    • pp.389-398
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    • 2013
  • Studies of the thermal properties of various rock types obtained from several locations in Korea have revealed significant differences in thermal conductivities in the thermal response test (TRT), which has been applied to the design of a ground-source heat pump system. In the present study, we aimed to compare the thermal conductivities of the samples with those obtained by TRT. The thermal conductivities of soil and rock samples were 1.32W/m-K and 2.88 W/m-K, respectively. In comparison, the measured TRT value for thermal conductivity was 3.13W/m-K, which is 10% higher than that of the rock samples. We consider that this difference may be due to groundwater flow because abundant groundwater is present in the study area and has a hydraulic conductivity of 0.01. It is natural to consider that the object of TRT is to calculate the original thermal conductivity of the ground, following the line source theory. Therefore, we conclude that the TRT applied to a domestic standing column type well is not suitable for a line source theory. To solve these problems, values of thermal conductivity measured directly from samples should be used in the design of ground-source heat pump systems.

Analysis of Thermal Comfort Factor′s Distribution in Convective Heating Space (대류난방공간에서 온열쾌적조건의 분포상태 분석에 관한 연구)

  • 공성훈
    • Journal of the Korean housing association
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    • 제6권1호
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    • pp.31-37
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    • 1995
  • The purpose of this study is to analyse the distribution of thermal sensation response and thermal environment condition in convective heating space. The contents of this study are as follows: 1)the spatial distributions of thermal conditions are measured 2)the thermal sensation vote of residents is taken in order to investigate the relation between thermal condition and human thermal sensation in sedentary condition 3)to analyse the distribution of subject's thermal sensation vote and thermal environment condition by two methods-regression method and graph method.

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Study on Analytical and Empirical Methods for Assessing Geo-Heat Transfer Characteristics (지중열전달특성 평가에 관한 해석 및 실험적 방법에 관한 연구 - 지중 열물성치 및 보어 홀 열 저항 평가 -)

  • Park Jun-n;Baek Nam-Choon
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2005년도 춘계학술대회
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    • pp.427-432
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    • 2005
  • This study treats the advantage of in situ line source method measuring the heat transfer capacity of a borehole, using mobile equipment, to determine the thermal properties of the entire borehole system such as thermal conductivity, diffusiveity. volumetric heat capacity, and borehole thermal resistance. The results from the response test include not only the thermal properties of the ground and the borehole, but also conditions that are difficult to estimate, e,g. natural convection in the boreholes, asymmetry in the construction, etc. In this study, 1) theoretical in situ methods for assessing working fluid temperature variation in V-type PE tube have been introduced, and 2) TRTE(Thermal Response Test Equipment) has been built based on these kinds of theoretical in situ methods. Basically TRTE consists of a pump, a heater and temperature sensors for measuring the inlet and outlet temperatures of the borehole. In order to make equipment easily transportable it is set up on a small trailer. Since the response test takes above two days to execute, the test was fully automatic in recording measured data using Labview DAS(Data acquisition system) program. The test was demonstrated in the course of intensive research in this field through the one site at Ulsan city in Korea. From this kind of thermal properties test of borehole systems in situ, the design of the borehole system can be optimized regarding the total geological, hydro-geological and technical conditions at the location.

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