• Title/Summary/Keyword: Temperature Difference Measurement

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Temperature distribution analysis of steel box-girder based on long-term monitoring data

  • Wang, Hao;Zhu, Qingxin;Zou, Zhongqin;Xing, Chenxi;Feng, Dongming;Tao, Tianyou
    • Smart Structures and Systems
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    • v.25 no.5
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    • pp.593-604
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    • 2020
  • Temperature may have more significant influences on structural responses than operational loads or structural damage. Therefore, a comprehensive understanding of temperature distributions has great significance for proper design and maintenance of bridges. In this study, the temperature distribution of the steel box girder is systematically investigated based on the structural health monitoring system (SHMS) of the Sutong Cable-stayed Bridge. Specifically, the characteristics of the temperature and temperature difference between different measurement points are studied based on field temperature measurements. Accordingly, the probability density distributions of the temperature and temperature difference are calculated statistically, which are further described by the general formulas. The results indicate that: (1) the temperature and temperature difference exhibit distinct seasonal characteristics and strong periodicity, and the temperature and temperature difference among different measurement points are strongly correlated, respectively; (2) the probability density of the temperature difference distribution presents strong non-Gaussian characteristics; (3) the probability density function of temperature can be described by the weighted sum of four Normal distributions. Meanwhile, the temperature difference can be described by the weighted sum of Weibull distribution and Normal distribution.

Development of Automatic Measurement of Body Temperature by Taking the Temperature of Milk while Milking in Dairy Cattle (젖소에서 유즙체온 측정을 이용한 체온 자동 측정 방법의 개발)

  • 김용준;한종현;이수영;한병성;김동원
    • Journal of Veterinary Clinics
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    • v.19 no.1
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    • pp.37-42
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    • 2002
  • To develop an automatic detecting system of body temperature of dairy cattle while milking, measurement of the temperature of mammary skin using three thermometers attached into the lining of teat cup was carried out for 23 dairy cattle, whereas measurement of the temperature of milk while milking was also performed for 263 animals. For the latter experiment, three thermometers were attached at 10cm(left and right) and 20 cm away from an individual milk collector on the milk transporting hose. Taking the rectal temperature was accompanied all the time for the experiments. The measurement of the temperature of mammary skin using teat cup was successful for 11 of 23 dairy cattle(47.8%) and the mean temperature was $33.5^{\circ}C$ with the mean difference of $5.2^{\circ}C$ from the mean rectal temperature. The measurement of the temperature of milk using the thermometers onto the milk transporting hose while milking was very successful , From 37.3 to $38.4^{\circ}C$ of rectal temperature, the temperature of milk was almost the same and from 38.5 to $39.5^{\circ}C$ of rectal temperature, the temperature of milk tended to be low with the difference of 0.1$^{\circ}C$. From 39.6 to $41^{\circ}C$ of rectal temperature, the temperature of milk tended to be low with the difference of $0.2-0.6^{\circ}C$. These results indicated that automatic detection of body temperature whether low or high can be possible if the temperature of milk is taken while milking and if it is connected to the integration system by on-line.

Reliability Assessment of Temperature Indicator for Simplified Measurement on Conservation Environment of Cultural Heritage (문화재 보존환경 간이 측정을 위한 온도지시카드 신뢰성 평가)

  • Lim, Bo-A;Shin, Eun-Jeong;Lee, Sun-Myung
    • 보존과학연구
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    • s.31
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    • pp.59-68
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    • 2010
  • Cultural heritages are damaged by surrounding several environmental factors. Main factors are temperature, humidity, light, atmosphere and indoor pollutant, organism, etc. Therefore, to prevent damage of cultural heritage from such environmental factor, conservation environment monitoring becomes more important. Indicator is one of the simple method for environment monitoring. It can be used without expensive and complex equipments. However, it should be performed scientific examination for application to cultural heritage. In this study, some Temperature Indicators were chosen and reliability assessment was carried out for application to cultural heritage. Brightness($L^*$) is selected for reliability assessment factor. As a result of lab test, Temperature Indicators were not influenced greatly in humidity change. When they were exposed to setting temperature, the color was changed in setting temperature area and ${\pm}2^{\circ}C$ part of setting temperature. Especially brightness value was high in setting temperature area. Also, Temperature Indicators were stabilized after about 16 minutes when were exposed to temperature difference of $10^{\circ}C$ and when temperature difference with exposure environment is smaller, stabilization time shortened. Therefore, it is a possible to confirm that selected Temperature Indicator is reliable product through measurement of color difference value and naked eye observation.

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Structural damage detection including the temperature difference based on response sensitivity analysis

  • Wei, J.J.;Lv, Z.R.
    • Structural Engineering and Mechanics
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    • v.53 no.2
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    • pp.249-260
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    • 2015
  • Damage detection based on a reference set of measured data usually has the problem of different environmental temperature in the two sets of measurements, and the effect of temperature difference is usually ignored in the subsequent model updating. This paper attempts to identify the structural damage including the temperature difference with artificial measurement noise. Both local damages and the temperature difference are identified in a gradient-based model updating method based on dynamic response sensitivity. The sensitivities of dynamic response with respect to the system parameters and temperature difference are calculated by direct integration method. The measured dynamic responses of the structure from two different states are used directly to identify the structural local damages and the temperature difference. A single degree-of-freedom mass-spring system and a planar truss structure are studied to illustrate the effectiveness of the proposed method.

Measurement of Sound Speed Following the Fluid Temperature Using Acoustic Inspection Device

  • Jeon, E.S.;Kim, W.T.;Kim, I.S.;Park, H.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.30 no.3
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    • pp.207-211
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    • 2010
  • In this paper, the fluid AID(acoustic inspection device) was developed to measure SOS(speed of sound) since fluids used in most of industrial fields have different properties and its equipment is highly expensive. From AID developed, it is intended to get potentially the capability to distinguish the kind of fluid using the measurement by the SOS at various fields. In order to measure the sound speed of specific fluids, the measurement system and ultrasonic sensors are composed. The fluid used in the experimental work are soybean oil, glycerin, diesel oil and the error of time difference due to the container wall is extracted for preliminary experiment. As results, the variations of sound speed according to the temperature change of target fluid were analyzed and the polynomial equations were proposed.

The calculation and Measurement Methods for G/T of the Telemetry Small Aperture Antenna (원격자료수신장비 소형반사판 안테나 G/T 예측 및 측정)

  • Kim, Chun-Won;An, Na-Gyun;Kim, Dong-Hyun;Cho, Byung-Lok
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.50 no.9
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    • pp.657-662
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    • 2022
  • In this paper, the calculation using simulation and two measurement methods for G/T of the telemetry are analyzed. Antenna gain and noise temperature are calculated by using ICARA and Antenna Noise Temperature Calculator. System G/T were calculated by using Antenna gain/noise temperature, LNA gain/noise temperature, cable loss. The first G/T measurement method is Y-factor measurement method, which is to calculate G/T by comparing LNA noise temperature and a signal level difference when an antenna and a 50ohm termination are respectively connected to an LNA input terminal Second method is Solar calibration measurement method that is to calculate G/T by comparing noise level difference when looking at the sun and lowest level point. Finally, the accuracy was reviewed by comparing the G/T calculation results with the two measurement methods, and the optimal measurement method according to antenna performance and operating environment was presented.

A Study on the Vertical Temperature Difference of Steel Box Girder Bridge by Field Measurement (실측에 의한 강박스거더교의 상하 온도차에 대한 연구)

  • Lee, Seong-Haeng;Park, Young-Chun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.8
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    • pp.545-551
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    • 2018
  • For domestic application of the temperature gradient model proposed by foreign design standards, a specimen of steel box girder bridge was fabricated with the following dimensions: 2.0 m width, 2.0 m height and 3.0 m length. Temperature was measured using 24 temperature gauges during the summer of 2016. The reliability of the measured data was verified by comparing the measured air temperature with the ambient air temperature of the Korea Meteorological Administration. Of the measured gauges, four temperature gauges that can be compared with the temperature difference of the Euro code were selected and used to analyze the distribution of the measured temperatures at each point. The reference atmospheric temperature for the selection of the maximum temperature difference was determined by considering the standard error. Maximum and minimum temperatures were calculated from the four selected points and the resulting temperature difference was calculated. The model for the temperature difference in the steel box girder bridge was shown by graphing the temperature difference. Compared to the temperature distribution of the Euro code, the presented temperature difference model showed a temperature difference of $0.9^{\circ}C$ at the top and of $0.3^{\circ}$ to $0.4^{\circ}C$ at the intermediate part. These results suggested that the presented model could be considered relatively similar to the Euro code The calculated standard error coefficient was 2.71 to 2.84 times the standard error and represents a range of values. The proposed temperature difference model may be used to generate basic data for calculating the temperature difference in temperature load design.

제너 다이오드를 이용한 공기 유속계측 장치개발

  • 김영재;김희식;조흥근
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.496-500
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    • 1996
  • An air flow measurement device is proposed. The thermal characteristic of a semiconductor element is adopted as a cooling parameter of thermal convection rate. The difference between forced convection and natural convection of two Zener diodes results enough difference in temperature. Experiment at various air flow conditions shows the measuring capability of the air flow in a duct. This measuring device has some merits, such as a reliability n hard field condition, simple circuit for signal processing, small volume of the element, less air flow resistance, independance of various ai temperature. The experimental result shows that it is an exact and usefull air flow measurement device.

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Justification of Beauty through Changes in Body Temperature of Dogs Before and After Beauty Treatment (미용 전, 후에 반려견의 체온변화를 통한 미용의 당위성)

  • Han-Gyel, Choi
    • Journal of Environmental Science International
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    • v.32 no.2
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    • pp.145-148
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    • 2023
  • The purpose of this study was to investigate the changes in body temperature of canine via their hair lengths before and after grooming. A total of 120 companion canines were used in this study for a total of 6 weeks, and 20 dogs each week consisted of both 10 poodles and 10 malteses (five females and males). For accurate temperature measurement, the anal depth was measured at approximately 1.5 cm. Temperature before and after grooming was measured at 10 am and after more than three hours, respectively. There was statistical significance (p<0.05) in body temperature changes for male poodles at 1, 2, and 3 weeks and for female poodles at 1, 3, 4, and 5 weeks, and the total period showed a statistical difference for both male and female poodles (p<0.05). In addition, male and female malteses had an effect (p<0.05) on changes in body temperature at 1 and 6 weeks and only at 4 weeks, respectively. For total period, there was a statistical difference in male and female poodles (p<0.05). Moreover, when the temperature changes of females were compared, there was no remarkable difference. In conclusion, the body temperatures of both male and female dogs according to the length of their hair were lower after grooming than before grooming. The measurement of body temperature three hours after grooming, which could reduce stress or other factors, is judged to be able to help customers who are worried about clipping.

ON MEASURING THE WELDING TEMPERATURE OF CONNECTOR

  • Deng Jyh-jeng
    • Proceedings of the Korean Society for Quality Management Conference
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    • 1998.11a
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    • pp.361-377
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    • 1998
  • The measurement of welding temperature of connector is usually performed with an infra red temperature gauge. However, the factors, which influence the temperature measurement, are rarely known. This research used the welding temperature measurement of the connector as an example, applying the experimental design, in two-phase experiments, to search the affecting factors. In phase-I experiment, we used a resolution III, seven-factor fractional factorial design with two levels for each factor. The result showed that none of the factor was significant in affecting the welding temperature when the type I error ${\alpha}$ was 0.05. Next, we did the phase-II factorial experiment with three factors and each factor had three levels. The experiment showed the experimental time was significant in affecting the temperature measurement when the type I error ${\alpha}$ was 0.05. Further Duncan's multiple range tests on the second experimental data showed that the later the experimental time, the weaker the light intensity could have on the temperature measurement and the average of the highest temperatures was lower. Moreover, the later the experimental time, the smaller was the variance of the temperature measurement and the difference between the averages of the highest and the lowest temperatures was also lower.

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