• Title/Summary/Keyword: TEMPERATURE

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Characteristics of Water Temperature Inversion Observed in a Region West of Jeju Island in April 2015 (2015년 4월에 제주 서부해역에서 발생한 수온역전층 특성)

  • Kim, Seong Hyeon
    • Ocean and Polar Research
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    • v.42 no.2
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    • pp.97-113
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    • 2020
  • In-situ observations were carried out in April 2015 to investigate the occurrence of water temperature inversion in a region west of Jeju Island. Analysis of in-situ in the western part of Jeju island showed that cold water moved to the southeast from the surface to the middle layer and warm water moved from the middle to the lower layer of the northwest direction. The water temperature inversion occurred at 84 stations (63.1%) out of 133 stations. At the boundary of the water temperature inversion layer, it was formed in the middle layer and disappeared. In the strongly appearing, it started from the middle layer to the lower layer. The shape of the water temperature inversion layer was different. As a result of horizontal water temperature slope analysis of the water temperature inversion zone, maximum 0.23℃/km was obtained and the mean was 0.06℃/km. The role of water temperature inversion as an indicator to determine the formation of water front. As a result of the water mass analysis, Jeju Warm Current Water and Tsushima Warm Current Water of high temperature and high salt intruded from the middle to the bottom. In the middle layer occurred as the Yellow Sea Cold Water of low water temperature and low salinity expanded.

A Study on Generating Process of Regional Balance Point Temperature for Heating Degree-days in Korea (국내 난방도일의 지역별 균형점온도 산정 과정에 관한 연구)

  • Park, So Min;Song, Doo Sam
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.9
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    • pp.482-495
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    • 2017
  • Degree-days are practically used as a tool to estimate energy consumption for heating and cooling. Degree-days are calculated by summing differences of balance point temperature and outside temperature for the analyzed period. Determining balance point temperature is a key point in calculating accurate degree-days. However, ASHRAE standards are used for balance point temperature in Korea because balance point temperature considering climate conditions and building thermal performance is not proposed in Korea. This study proposes the process to generate balance point temperature for heating degree-days considering Korean climate and building conditions. Also, a new balance point temperature for three regions in Korea will be suggested in this study. Balance point temperature of Seoul is approximately $15.0^{\circ}C$, lower than the current standard of $18.3^{\circ}C$. Balance point temperature of Seoul considering climate conditions and building performance can be different from the ASHRAE suggested value ($18.3^{\circ}C$). Results revealed the current standard for balance point temperature should be changed considering climate and building conditions in Korea.

Elimination of environmental temperature effect from the variation of stay cable force based on simple temperature measurements

  • Chen, Chien-Chou;Wu, Wen-Hwa;Liu, Chun-Yan;Lai, Gwolong
    • 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.

Investigation of Urban High Temperature Phenomenon in Summer using the High Density Ground Monitoring System in Daegu Metropolitan Area (지상 고밀도 관측 시스템을 이용한 대구의 여름철 고온현상 조사)

  • Kim, Sang-Heon;Cho, Chang-Bum;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.23 no.9
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    • pp.1619-1626
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    • 2014
  • We analyzed diurnal variations in the surface air temperature using the high density urban climate observation network in Daegu metropolitan city, the representative basin-type city in Korea, in summer, 2013. We used a total of 28 air temperature observation points data(16 thermometers and 12 AWSs). From the distribution of monthly average air temperature, air temperature at the center of Daegu was higher than the suburbs. Also, the days of daily minimum air temperature more than or equal to $25^{\circ}C$ and daily maximum air temperature more than or equal to $35^{\circ}C$ at the schools near the center of Daegu was more than those at other schools. This tendency appeared more clearly on the days of daily minimum air temperature more than or equal to $25^{\circ}C$. Also, the air temperature near the center of the city was higher than that of the suburbs in the early morning. Thus it was indicated that the air temperature was hard to decrease as the bottom of the basin. From these results, the influence of urbanization to the formation of the daily minimum temperature in Daegu was indicated.

A literature study on change of surperficial temperature (체표 온도 변화에 대한 문헌 고찰)

  • Kim, Sang-Rok;Lee, Chang-Hoon;Cho, Jung-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub
    • Journal of Oriental Medical Thermology
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    • v.4 no.1
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    • pp.54-60
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    • 2005
  • Object: A study on the changes of superficial temperature as the ambient temperature varies. Method: After performing research on the physiologic mechanism of heat loss from skin, heat transfer to skin and heat productions of body, the conclusions would be drawn from experiments on temperature changes in every parts of the body as ambient temperature varies . Result and conclusion: Superficial temperature is in equilibrium with ambient temperature after a certain period. Part of the body with big change in superficial temperature tends to have slower temperature change and longer time for adaptation than the part with small change in superficial temperature. The temperature difference between left and right side of the body needs no attention. If adequate adaptation time, a short-period living supervision prior to measurements and appropriate indoor environment management are provided, meaningful conclusion would be attained for infrared thermal diagnosis.

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An Environmental Effect on Productivity of Flounder Culture Farms (넙치양식장 환경에 따른 생산성에 관한 연구)

  • Eh, Youn-Yang
    • The Journal of Fisheries Business Administration
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    • v.42 no.3
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    • pp.79-93
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    • 2011
  • Water temperature of Oliver flounder farm affects Oliver flounder growth and mortality rate. In laboratory experimental tanks, optimal water temperature was $22.5^{\circ}C$($21{\sim}24^{\circ}C$) and cultivatable water temperature was $12{\sim}28^{\circ}C$. The purpose of this study is to identify applicable and useful water temperature of Oliver flounder farm in case of actual farming. The data applied in the analysis was collected from Jeju island. In the study, various analytical methods including productivity analysis, regression analysis, statistical analysis were conducted for 13 Oliver flounder culture farms. The result of analysis can be summarized as follows : First, growth rate on the Oliver flounder culture farms was related to mean of water temperature, variation of water temperature and low water temperature. Second, survival rate on the Oliver flounder culture farms was related to mean of water temperature. In case of including Oliver flounder stocking density, defined as the surface area of Oliver flounder per $m^2$ of water surface area, survival rate strongly related to mean of water temperature, variation of water temperature, cultivating capability and stocking density. Third, production weight per $m^2$ of water surface area was strongly related to mean of water temperature, low water temperature and cultivating capability. Growth rate and survival rate was analyzed into mediate variable character.

Thermoregulatory Responses in the Elderly and the Young under the Ondol System (온돌난방에서 노인과 청년의 피부온 반응 비교)

  • 정유정;최정화
    • Journal of the Korean Society of Clothing and Textiles
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    • v.22 no.1
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    • pp.149-158
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    • 1998
  • The purpose of this study was to investigate the effect of age on the human thermoregulatory responses and to obtain the basic information of the Korean thermophysiological characteristics under the traditional Korean floor heating system-Ondol. The participants consisted of 10 elderly women, 4 elderly men(over 65 years), 10 young women and 5 young men(in twenties). They were exposed to temperature-controlled Ondol room(20$\pm$1$^{\circ}C$, 50$\pm$5%R.H., floor surface temperature: 30$\pm$1$^{\circ}C$) for 60 minutes and wore the same experimental clothing. The postures were performed sitting and supine on the floor. In each pose, rectal temperature, skin.temperature of 10 areas, mean skin temperature, clothing microclimate, body fat were measured. The results were as follows; 1. The rectal temperature gradually decreased and mean skin temperature gradually increased in young and old groups in both supine and sitting pose on heated Ondol floor for 60 minutes. 2. Rectal temperature was different in each pose. The rectal temperature decreased 0.1$^{\circ}C$ in both groups under the condition of sitting and decreased 0.2'c in elderly group under the condition of supine. In supine pose, elderly group was more declined than young group. Mean skin temperature increased 0.5$^{\circ}C$ in both poses, both groups.

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Climate Change and Health - A Systemic Review of Low and High Temperature Effects on Mortality (기후변화와 건강 - 저온과 고온이 사망에 미치는 영향에 관한 체계적 고찰)

  • Lim, Youn-Hee;Kim, Ho
    • Journal of Environmental Health Sciences
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    • v.37 no.6
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    • pp.397-405
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    • 2011
  • Objectives: The impact of climate change on the health has been of increasing concern due to a recent temperature increase and weather abnormality, and the research results of the impact varied depending on regions. We synthesized risk estimates of the overall health effects of low and high temperature taking account of the heterogeneity. Methods: A comprehensive literature search was conducted using PUBMED to identify journal articles of low and/or high temperature effects on mortality. The search was limited to the English language and epidemiological studies using time-series analysis and/or case-crossover design. Random-effect models in meta analysis were used to estimate the percent increase in mortality with $1^{\circ}C$ temperature decrease or increase with 95% confidence intervals (CI) in cold or hot days. Results: Twenty three studies were presented in two tables: 1) low temperature effects; 2) high temperature effects on mortality. The combined effects of low and high temperatures on total mortality were 2% (95% CI, 1-4%) per $1^{\circ}C$ decrease and 4% (95% CI, 2-5%) per $1^{\circ}C$ increase of temperature, respectively. Conclusions: This meta analysis found that both low and high temperatures affected mortality, and the magnitude of high temperature appeared to be stronger than that of low temperature.

Effect of Fluctuating Temperature on Development of the Beet Armyworm, Spodoptera exigua (H bner) (변온조건이 파밤나방 [Spodoptera exigua (H bner)] 발육에 미치는 영향)

  • 김용균;권도형;김찬영
    • The Korean Journal of Soil Zoology
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    • v.5 no.2
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    • pp.119-123
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    • 2000
  • Effect of fluctuating temperatures on the development of the immature beet armyworm, Spodoptera exigua (H bner), was analyzed. At constant rearing temperature regimes, the estimated developmental threshold temperatures were varied among stages and instars, but had an average 13$^{\circ}C$ from egg hatch to adult emergence. Based on the 13$^{\circ}C$ threshold temperature, we set up three different rearing temperature regimes having the same day-degrees. Two fluctuating temperature regimes changed significantly the developmenta1 period expected by the constant rearing temperature regime. Under the same thermophase temperature (25$^{\circ}C$), the thermocycling regime with the higher cryophase temperature (10$^{\circ}C$) decelerated the developmental rate probably by lowering temperature limit thor development, but that with the lower cryophase temperature (5$^{\circ}C$) gave a negative developmental effect.

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The Prediction of Water Temperature at Saemangeum Lake by Neural Network (신경망모형을 이용한 새만금호 수온 예측)

  • Oh, Nam Sun;Jeong, Shin Taek
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.1
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    • pp.56-62
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    • 2015
  • The potential impact of water temperature on sea level and air temperature rise in response to recent global warming has been noticed. To predict the effect of temperature change on river water quality and aquatic environment, it is necessary to understand and predict the change of water temperature. Air-water temperature relationship was analyzed using air temperature data at Buan and water temperature data of Shinsi, Garyeok, Mangyeong and Dongjin. Maximum and minimum water temperature was predicted by neural network and the results show a very high correlation between measured and predicted water temperature.