• Animal Bioscience
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• v.34 no.7
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• pp.1235-1242
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• 2021

Objective: The purpose of this study was to identify through infrared thermal imaging technology the facial surface temperature (FST) of laying hens in response to the variations in their thermal environment, and to identify the regional differences in FST to determine the most stable and reliable facial regions for monitoring of thermoregulatory status in chickens. Methods: Thirty Hy-Line Brown hens (25-week-old) were sequentially exposed to three different thermal conditions; optimal (OT, 22℃±2℃), low (LT, 10℃±4℃), and high temperature (HT, 30℃±2℃). The mean values of FST in five facial regions including around the eyes, earlobes, wattles, beak and nose, and comb were recorded through infrared thermography. The maximum FST (MFST) was also identified among the five face-selective regions, and its relationship with temperature-humidity index (THI) was established to identify the range of MFST in response to the variations in their thermal environment. Results: Hens exposed to OT condition at 15:00 displayed a higher temperature at wattles and around the eyes compared to other regions (p<0.001). However, under LT condition at 05:00 to 08:00, around the eyes surface temperature showed the highest value (p<0.01). In HT, wattles temperature tended to show the highest temperature over almost time intervals. Main distribution regions of MFST were wattles (63.3%) and around the eyes (16.7%) in OT, around the eyes (50%) in LT, and wattles (62.2%) and comb (18.3%) in HT. The regression equation between MFST and THI was estimated as MFST = 35.37+0.2383×THI (R² = 0.44; p<0.001). Conclusion: The FST and the frequency of MFST in each facial region of laying hens responded sensitively to the variations in the thermal environment. The findings of this experiment provide useful information about the effect of the thermal conditions on the specific facial regions, thus offering an opportunity to stress and welfare assessment in poultry research and industry.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.5
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• pp.651-660
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• 1998

In the LPCVD reactor the temperature variations within the wafer load are the most important factor to maintain the thickness of the materials deposited on the surface of the wafer constant and to affect the deformation of each wafer. In this study the temporal variations of radial and axial temperature nonuniformities of each wafer in the LPCVD reactor are numerically estimated by assuming diffuse reflection. To verify the validity of the present numerical results, the present results obtained from the transient analysis are compared with those of Badgwell's work in which a steady-state condition was assumed. The main objective of this work is to determine the temporal variations of the temperature of each wafer in the LPCVD process since the wafers experience severe change in temperature in the early stage of the process.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.478-486
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• 1993

For satisfactory greenhouse culture, environmental factors must be kept in proper conditions. Therefore, it is important to know relations between environmental conditions and greenhouse systems. In this study, the environment variations and distributions in different types of greenhouses were measured and analyzed. The elements of environment analyzed were temperature , relative humidity, illumination, carbon dioxide and wind velocity. The analyzed greenhouse types were three different types. One of them, A type, was propagation model type by government and the other one, B type, was multiple continuous arches type which was made by farmers himself. The last one, C type, was single arch type which has no environment control system without manual temperature keeping method. The results of this study can be used for reasonable greenhouse environments managements and control.

• The Korean Journal of Physiology
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• v.6 no.2
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• pp.23-30
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• 1972

Contrary to most of European and American investigators failed to find out the seasonal variations of basal metabolic rate in man, Japanese and Korean investigators reported the increase in winter, decrease in summer season. But the causes of variation were not found clearly. To find out whether metabolic acclimatization to climate could be arise or not in human being, the basal metabolic rate was determined monthly for a period of one year in Airmen volunteers who live in Seoul, with 9 l Collins spirometer. The results obtained were as follows: 1. The average ambient temperature was lowest in February $(-5.88^{\circ}C)$ and highest in July $(27.34^{\circ}C)$. 2. Basal metabolic rate was lowest in June and highest in December showing seasonal variations. Interestingly, the increase of basal metabolic rate followed after the drop of ambient temperature below $0^{\circ}C$ (December) and the decrease followed after the elevation of ambient temperature from optimum to hot (June) or cold to warm (March). 3, Mean skinfold thickness increased in spring, decreased in winter. 4. These findings indicate that the basal metabolic rate of Korean reveals the seasonal variation affected by ambient temperature highly.

• Journal of Biosystems Engineering
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• v.18 no.1
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• pp.60-70
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• 1993

In this study, the environment variations and distributions in different types of greenhouses were measured and analyzed. The elements of environment analyzed were temperature, relative humidity, illumination, carbon dioxide and wind velocity. The analyzed greenhouse types were auto-multi type which has an automatic environment control system and multiple continuous arches, regular-multi type which has an temperature control system and multiple continuous arches, and single arch type which has no environment control system without manual temperature keeping method. The results of this study can be used for the greenhouse building and managements.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.799-804
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• 2013

The sensor/actuator active sensor diagnostics procedure, where the sensors/actuators are confirmed to be functioning properly during operation, is a critical component to successfully complete the structural health monitoring (SHM) process with large numbers of active sensors typically installed in a structure. The basis of this process is to track the changes in the capacitive value of piezoelectric materials, which shows up in measured admittance. Due to the temperature dependent nature of piezoelectric materials, we investigated the effects of temperature variations on sensor diagnostic process. The effect of temperature variations found to be remarkable, modifying the measured capacitive values significantly. In addition we analyzed the effect of bonding agents between a PZT patch and a host structure. This paper summarizes considerations needed to develop such sensor diagnostic processes, experimental procedures and results, and additional issues that can be used as guidelines for future investigations.

• Smart Structures and Systems
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• v.19 no.2
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• pp.137-149
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• 2017

Under the interference of the temperature effect, the alternation of cable force due to damages of a cable-stayed bridge could be difficult to distinguish. Considering the convenience and applicability in engineering practice, simple air or cable temperature measurements are adopted in the current study for the exclusion of temperature effect from the variation of cable force. Using the data collected from Ai-Lan Bridge located in central Taiwan, this work applies the ensemble empirical mode decomposition to process the time histories of cable force, air temperature, and cable temperature. It is evidently observed that the cable force and both types of temperature can all be categorized as the daily variation, long-term variation, and high-frequency noise in the order of decreasing weight. Moreover, the correlation analysis conducted for the decomposed variations of all these three quantities undoubtedly indicates that the daily and long-term variations with different time shifts have to be distinguished for accurately evaluating the temperature effect on the variation of cable force. Finally, consistent results in reducing the range of cable force variation after the elimination of temperature effect confirm the validity and stability of the developed method.

• Journal of Environmental Science International
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• v.3 no.4
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• pp.381-391
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• 1994

This paper presents the disributions and variations of CO, $CO_2$, number of people and temperature in underground shopping center and subway of Seomyeon and Jagalchi in Pusan, Korea for two times during October and November in 1993, respectively. NDIR analyzer is used for the analysis of CO and $CO_2$. The temperature is obtained from a mercury therometer. The results o( observation and analysis show that the variation of $CO_2$ is strongly related to number of people and temperature. The correlation coefficients between temperature, COB and Number of people are higher than 0. at both of places. The pollution of CO2 of Seomyeon is higher than that of Jagachi in underground shopping center. However, CO is not correlated with the temperature and the Number of people. From the results, we found that the indoor air quality monitoring system is needed for the prevention of the underground air Pollution.

• Journal of Welding and Joining
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• v.8 no.4
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• pp.58-68
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• 1990

The formation of thermal stresses by plasma spraying is generally considered as adverse. Therefore, the knowledge of stress distribution in the deposited layer during and after plasma spraying will be of special interest. In this study finite difference heat transfer analysis and finite element stress analysis were carried out to predict the change of stress distribution in the plasma coated layer with the variations of preheat temperature, number of scan, particle size, and bond coat. The results of the numerical analysis were as follows: 1) Transient stresses developed in the coated layer were up to the level of yiedl strength at the temperature. 2) The tensile stresses were developed in the deposited layer and the surface of the substrate, but the compressive stresses were developed in the rest of the substrate. 3) Transient and residual stresses were significantly affected by the preheat temperature. 4) The variations of temperature of powder particle and number of torch scan changed tensile stress distribution, but made no difference on the magnitude of the stresses. 5) Bond coated layer reduced the stree level of deposited layer.

• Proceedings of the KWS Conference
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• 2002.05a
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• pp.285-287
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• 2002

This study is investigated in variations of micro-structures and mechanical properties of Ti/SUS321L joint with bonding temperature and time using brazing method. According to increasing bonding temperature and time, it was observed the thickness of their reaction layer increased. In tensile test, it was examined that the tensile strength had maximum value at the bonding time of 5min and decreased after bonding time over 5min because of increasing their oxides and intermetallic compounds.