• Title/Summary/Keyword: Temperature sensitivity

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Qualification for Impedance-based Rain Detectors

  • Lee, Sang-Wook;Choi, Byung Il;Kim, Jong Chul;Woo, Sang-Bong;Kim, Yong-Gyoo
    • Journal of Sensor Science and Technology
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    • v.26 no.3
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    • pp.149-154
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    • 2017
  • Detection of rain is one of the essential weather factors that are monitored by automatic weather stations in Korea. In this work, we studied the operation standards required for impedance-based rain detectors in terms of surface temperature and sensitivity, in an effort to establish a qualification procedure for rain detectors. The surface temperature of rain detectors was measured at varying air temperatures from $-30^{\circ}C$ to $20^{\circ}C$, considering the hypothetical presence and absence of rain/snow. In addition, the sensitivity of rain detectors was studied generating artificial raindrops of regular size. The sensitivity was evaluated in terms of the critical number of droplets that triggers the activation of the rain detector. We found that the sensitivity is affected by stationary, horizontal, and vertical droplet deposition methods. The critical number of droplets for the stationary deposition is higher than that for both horizontal and vertical depositions, which provides the maximum limit of droplets required to activate the detector. Based on our experiments considering surface temperature measurements and sensitivity tests, we suggest a revised version of surface temperature and sensitivity requirements for the qualification of impedance-based rain detectors.

A study on the sensitivity analysis of processing parameters for the laser surface hardening treatment (레이저 표면 경화처리 긍정변수의 민감도 해석에 관한 연구)

  • 이세환;양영수
    • Proceedings of the KWS Conference
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    • 2000.10a
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    • pp.260-263
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    • 2000
  • A methodology is developed and many used to evaluate the response sensitivity of the thermal systems to variations in their design parameters. Technique for computing the sensitivity of temperature distributions to changes in processing parameters needed for deciding the more effective laser input parameters for laser surface hardening treatment are considered. In this study, a state equation governing the heat flow in laser surface treatment is analyzed using a three-dimensional finite element method and sensitivity data of the processing parameter obtained using a direct differentiation method applied for sensitivity analysis. The interesting processing parameter is taken as the laser scan velocity and characteristic beam radius( $r_{b}$) of the sensitivity of the temperature T versus v and $r_{b}$ is analyzed. And these sensitivity results obtained in another parameters are fixed condition. To verifying the numerical analysis results, hardened layer dimensions (width and depth) of the numerical analysis compared with the results of an experimental data.ata.

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Sensitivity Analysis of Processing Parameters for the Laser Surface Hardening Treatment by Using the Finite Element Method (유한요소법을 이용한 레이저 표면경화처리 공정변수의 민감도 해석)

  • 이세환;양영수
    • Journal of Welding and Joining
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    • v.19 no.2
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    • pp.228-234
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    • 2001
  • A methodology is developed and used to evaluate the response sensitivity of the thermal systems to variations in their design parameters. Technique for computing the sensitivity of temperature distributions to changes in processing parameters needed to decide the more effective laser input parameters for laser surface hardening treatment is considered. In this study, a state equation governing the heat flow in laser surface treatment is analyzed using a three-dimensional finite element method and sensitivity data of the processing parameter obtained using a direct differentiation method is applied to the sensitivity analysis. The interesting processing parameters are taken as the laser scan velocity and laser beam radius ( $r_{ b}$), and the sensitivities of the temperature T versus v and $r_{b}$ are analyzed. These sensitivity results are obtained with another parameters fixed. To verify the numerical analysis results, hardened layer dimensions (width and depth) of the numerical analysis are compared with the experimental ones.nes.

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Development of Short-Term Load Forecasting Algorithm Using Hourly Temperature (시간대별 기온을 이용한 전력수요예측 알고리즘 개발)

  • Song, Kyung-Bin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.4
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    • pp.451-454
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    • 2014
  • Short-term load forecasting(STLF) for electric power demand is essential for stable power system operation and efficient power market operation. We improved STLF method by using hourly temperature as an input data. In order to using hourly temperature to STLF algorithm, we calculated temperature-electric power demand sensitivity through past actual data and combined this sensitivity to exponential smoothing method which is one of the STLF method. The proposed method is verified by case study for a week. The result of case study shows that the average percentage errors of the proposed load forecasting method are improved comparing with errors of the previous methods.

A Novel Behavior, Bang-Sensitive Paralysis, Associated With The shibire Locus of Drosophila melanogaster

  • 김윤택
    • Environmental Mutagens and Carcinogens
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    • v.10 no.2
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    • pp.93-106
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    • 1990
  • The Drosophila temperature-sensitive mutant shibire (shi) is paralyzed at restrictive temperature by a reversible block in synaptic transmission. To explore the functional relationship among shi gene products, viability and temperature-sensitive paralytic behavior were quantitaively analyzed for four shi alleles, shi$^{ts1}$, shi$^{ts2}$, shi$^{ts4}$, and shi$^{ST139}$, and their heteroallelic combinations. The hemizygous combination of shi alleles over deficiency was not completely lethal. shi$^{ts2}$ exhibited distinctively higher viability than other alleles. A novel behavior, bang sensitivity, was also found in shi/Df(1). This bang-sensitive paralytic behavior was compared with that of the typical bang-sensitive mutant flies. Heterozygotes, shi/+, are more severe in temperature sensitivity than deficiency hemizygotes, Df(1)/+. Heteroallelic combinations of shi were less sensitive to high temperature than homozygotes. Among all allelic combinations, shi$^{ts2}$/shi$^{ts4}$ showed an unexpected extreme reduction in temperature sensitivity. The results of allelic interactions among 4 shi alleles suggest that the shi mutations examined behave as antimorphic alleles and that the gene product of shi are likely to function in multimeric forms.

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High Temperature Deformation Behavior of Rapid-Solidification Processed Al-18Si Alloy (급냉응고된 과공정 Al-Si합금의 고온변형특성에 관한 연구)

  • 김성일
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2000.04a
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    • pp.183-186
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    • 2000
  • The high temperature deformation behavior of spray-formed Al-19wt%Si-1.87wt%Mg-0.085wt.%Fe alloy was studied by torsion testing in the strain rate range of 0.001-1 sec-1 and in the temperature range of 300-500 $^{\circ}C$. The relationship between stress temperature and strain rate is expressed using the Power law. the behavior of dynamic recrystallization is showed in 300-35$0^{\circ}C$, 1-0.1sec-1 and the behavior of dynamic recovery is showed in 450-50$0^{\circ}C$, 0.01-0.001sec-1 The size of Si particles is mall when the temperature is low and the strain rate is high. The strain rate sensitivity(m) and the apparent activation energy(Q) indicate the dependence on strain rate and temperature for flow stress respectively. The hot ductility is high when m is high and Q is low. The maps of strain rate sensitivity and apparent activation energy suggest the optimum processing conditions.

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Fabrication and Characteristics of High-sensitivity Si Hall Sensors for High-temperature Applications (고온용 고감도 실리콘 홀 센서의 제작 및 특성)

  • 정귀상;노상수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.565-568
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    • 2000
  • This paper describes on the temperature characteristics of a SDB(silicon-wafer direct bonding) SOI(silicon-on-insulator) Hall sensor. Using the buried oxide $SiO_2$ as a dielectrical isolation layer, a SDB SOI Hall sensor without pn junction isolation has been fabricated on the Si/$SiO_2$/Si structure. The Hall voltage and the sensitivity of the implemented SOI Hall sensor show good linearity with respect to the applied magnetic flux density and supplied current. In the temperature range of 25 to $300^{\circ}C$, the shifts of TCO(temperature coefficient of the offset voltage) and TCS(temperature coefficient of the product sensitivity) are less than $\pm 6.7$$\times$$10^{-3}$/$^{\circ}C$ and $\pm 8.2$$\times$$10^{-4}$/$^{\circ}C$respectively. These results indicate that the SDB SOI structure has potential for the development of a silicon Hall sensor with a high-sensitivity and hip high-temperature operation.

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Research on Temperature Sensing Characteristics of Fiber Bragg Grating in Wide Temperature Range

  • Naikui Ren;Hongyang Li;Nan Huo;Shanlong Guo;Jinhong Li
    • Current Optics and Photonics
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    • v.8 no.2
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    • pp.162-169
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    • 2024
  • This study investigates the temperature sensitivities of fiber Bragg grating (FBG) across a broad temperature spectrum ranging from -196 ℃ to 900 ℃. We developed the FBG temperature measurement system using a high-temperature tubular furnace and liquid nitrogen to supply consistent high and low temperatures, respectively. Our research showed that the FBG temperature sensitivity changed from 1.55 to 10.61 pm/℃ in the range from -196 ℃ to 25 ℃ when the FBG was packaged with a quartz capillary. In the 25-900 ℃ range, the sensitivity varied from 11.26 to 16.62 pm/℃. Contrary to traditional knowledge, the FBG temperature sensitivity was not constant. This inconsistency primarily stems from the nonlinear shifts in the thermo-optic coefficient and thermal expansion coefficient across this temperature spectrum. The theoretically predicted and experimentally determined temperature sensitivities of FBGs encased in quartz capillary were remarkably consistent. The greatest discrepancy, observed at 25 ℃, was approximately 1.3 pm/℃. Furthermore, it was observed that at 900 ℃, the FBG was rapidly thermally erased, exhibiting variable reflected intensity over time. This study focuses on the advancement of precise temperature measurement techniques in environments that experience wide temperature fluctuations, and has considerable potential application value.

Development of a Personal Clothing Recommendation System that Reflects Individual Temperature Sensitivity (개인별 체감 온도를 반영한 개인 소장 의류 추천 시스템 개발)

  • Jeong, Byeong-Hui;Kim, Woo-Seok;Lee, Sang-Yong
    • Journal of Digital Convergence
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    • v.19 no.2
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    • pp.357-363
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    • 2021
  • In general, people choose clothes to wear when they go out, referring to real-time weather and temperature. However, it is difficult for an individual to use real-time weather information and his or her temperature sensitivity information to choose the right clothes from among the clothes he or she owns. Existing clothing recommendation systems developed to help with these problems have problems recommending clothes that are not clearly set in the clothing category and are not in the possession of the user. In addition, user-specific temperature sensitivity is not taken into account, resulting in inappropriate clothing recommendations for users. To solve these problems, this study developed a system that determines and registers clothing categories for the clothing owned by the user, and recommends customized clothing for each user by considering temperature sensitivity and real-time weather information. In the case of weather information, not only weather information such as temperature and wind direction, but also clothes based on temperature sensitivity were recommended based on the calculation of temperature sensitivities. A satisfaction survey of 65 university students was conducted to assess the system. As a result, 80% of the respondents were satisfied with the recommended clothing, indicating that the satisfaction of the system was good. Therefore, it is expected that this system will be highly utilized in real life as it will be recommended based on clothes owned by individuals, reflecting individual temperature sensitivity.

Optimal Positioning of Heating Lines in a Compression Molding Die Using the Boundary Element Method (경계요소법을 이용한 압축성형다이 가열선의 최적위치 설계)

  • 이부윤;조종래
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.6
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    • pp.1478-1485
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    • 1993
  • A shape optimization problem is formulated to determine the optimal position of heating lines in a compression molding die. The objective of the problem is that the cavity surface would be maintained by a prescribed uniform temperature. A boundary integral equation for the sensitivity of the temperature in terms of hole position is derived using the method of shape design sensitivity analysis. The boundary element method is employed to analyze the temperature and sensitivity field of the die. The sensitivity calculation algorithm is incorporated in an optimization routine. To demonstrate a numerical implementation, an example problem arising in thermal design of a compression molding die is dealt with, showing that the number of heating lines chosen for the die strongly affects the ultimate uniformity of the cavity surface temperature.