• Title/Summary/Keyword: CHANGE OF TEMPERATURE

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Prediction of Climate-induced Water Temperature using Nonlinear Air-water Temperature Relationship for Aquatic Environments (지구기후모형 기온변화에 따른 미래 하천생태환경에서의 수온 예측)

  • Lee, Khil-Ha
    • Journal of Environmental Science International
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    • v.25 no.6
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    • pp.877-888
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    • 2016
  • To project the effects of climate-induced change on aquatic environments, it is necessary to determine the thermal constraints affecting different fish species and to acquire time series of the current and projected water temperature (WT). Assuming that a nonlinear regression between the WT at individual stations and the ambient air temperature (AT) at nearby weather stations could represent the best relationship of air-water temperature, This study estimates future WT using a general circulation model (GCM). In addition, assuming that the grid-averaged observations of AT correspond to the AT output from GCM simulation, this study constructed a regression curve between the observations of the local WT and the concurrent GCM-simulated surface AT. Because of its low spatial resolution, downscaling is unavoidable. The projected WT under global warming scenario A2 (B2) shows an increase of about $1.6^{\circ}C$ ($0.9^{\circ}C$) for the period 2080-2100. The maximum/minimum WT shows an amount of change similar to that of the mean values. This study will provide guidelines for decision-makers and engineers in climate-induced river environment and ecosystem management.

Changes of Flowering Time in the Weather Flora in Susan Using the Time Series Analysis (시계열 분석을 이용한 부산지역 계절식물의 개화시기 변화)

  • Choi, Chul-Mann;Moon, Sung-Gi
    • Journal of Environmental Science International
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    • v.18 no.4
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    • pp.369-374
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    • 2009
  • To examine the trend on the flowering time in some weather flora including Prunus serrulata var. spontanea, Cosmos bipinnatus, and Robinia pseudo-acacia in Busan, the changes in time series and rate of flowering time of plants were analyzed using the method of time series analysis. According to the correlation between the flowering time and the temperature, changing pattern of flowering time was very similar to the pattern of the temperature, and change rate was gradually risen up as time goes on. Especially, the change rate of flowering time in C. bipinnatus was 0.487 day/year and showed the highest value. In flowering date in 2007, the difference was one day between measurement value and prediction value in C. bipinnatus and R. pseudo-acacia, whereas the difference was 8 days in P. mume showing great difference compared to other plants. Flowering time was highly related with temperature of February and March in the weather flora except for P. mume, R. pseudo-acacia and C. bipinnatus. In most plants, flowering time was highly related with a daily average temperature. However, the correlation between flowering time and a daily minimum temperature was the highest in Rhododendron mucronulatum and P. persica, otherwise the correlation between flowering time and a daily maximum temperature was the highest in Pyrus sp.

The Effect of Dynamic Strain Aging on the High Temperature Plastic Deformation Behaviour of Al-Mg Alloy (Al-Mg 합금의 고온 소성 변형 특성에 미치는 동적 변형 시효의 영향)

  • 이상용;이정환
    • Transactions of Materials Processing
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    • v.5 no.4
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    • pp.327-336
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    • 1996
  • The effect of dynamic strain aging on high temperature deformation behaviour of the A-Mg alloy was investigated by strain rate change tests and stress relaxation tests between 20$0^{\circ}C$and 50$0^{\circ}C$. Yield point, short stress transient and periodic discontinuities on the stress-strain curve were considered as an evidence of the effect of dynamic strain aging. With this criterion two distinct strain rate-temperature regimes could be manifested. Dynamic strain aging was considered to be effective in the high temperature-low strain rate regime, whereas dynamic recovery was a dominant deformation mechanism in the low temperature-high strain rate regime. It was found that dynamic strain aging in the high temperature deformation was governed by the mechcanism of diffusion-controlled, viscous dislocation movement.

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Equipment for Measuring the Adiabatic Temperature Rise of Concrete by Compensating Heat Loss (열손실량 보정을 통한 콘크리트 단열온도상승량 예측 장치)

  • Jin, Eun-Woong;Kim, Chin-Yong;Kim, Jin-Keun
    • Journal of the Korea Concrete Institute
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    • v.24 no.5
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    • pp.535-542
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    • 2012
  • Adiabatic temperature rise test for predicting heat of hydration in mass concrete is especially inconvenient in the field. In order to overcome the problem, the equipment to effectively and conveniently measure semi-adiabatic temperature change was developed. The main objective of this paper is to propose a new and simple equipment for measuring semi-adiabatic temperature rise by using insulation bottles. In order to predict exact heat loss of concrete using this device, it is required to assume the specific heat loss coefficient of the device by water temperature change inside the experimental device. According to experimental and analytical results, the adiabatic temperature rise does not have significant differences in changes of temperature and humidity of air, as well as initial temperature of water. By comparing adiabatic temperature rise tests, the equipment for measuring semi-adiabatic temperature change can be used to predict the hydration heat of concrete within sufficient accuracy.

Effects of Temperature and Salinity on Survival, Metabolism and Histological Change of the Rockfish, Sebastes schlegeli (수온과 염분이 조피볼락, Sebastes schlegeli의 생존, 대사 및 조직학적 변화에 미치는 영향)

  • YANG, Sung Jin;LEE, Jeong Young;SHIN, Yun kyung;HWANG, Hyung Kyu;MYEONG, Jeong-In
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.4
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    • pp.1068-1075
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    • 2016
  • The suitable temperature and salinity for the long-distance transportation for the rockfish were investigated by assessing survival rate, metabolism, histological change. All experimental groups showed survival rates of 100%. Daily Oxygen consumption rhythm was decreased during nights and increased during days. Average oxygen consumption was significantly decreased as temperature and salinity were decreased. Ammonia excretion was significantly increased as temperature and salinity were decreased. Histological changes were observed in the skin and gill of the rockfish exposed to 10 psu under all the temperature conditions, with larger changes at $4^{\circ}C$. Further, nucleus deformation and uniformity in the cytoplasm were also observed.

Material Recognition Using Temperature Response Curve Fitting and Fuzzy Neural Network

  • Young-C. Lim;Park, Jin-K;Ryoo, Young-J;Jang, Young-H;Kim, I-G.
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1995.10b
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    • pp.15-24
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    • 1995
  • This paper describes a system that can be used to recognize an unknown material regardless of the fuzzy neural network(FNN). There are some problems to realize the recognition 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 temperature. So, this paper proposes a practical method using curve fitting to remove above problems of memories and noise. and FNN is proposed to overcome the problem caused by the change of ambient temperature. Using the FNN which is learned by temperature responses on fixed ambient. Temperatures and known thermal conductivity, the thermal conductivity of the material can be inferred on various ambient temperatures. So the material can be recognized by the thermal conductivity.

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Temperature variation of the outer skin above specific acupoints induced by controlling mind : Pilot Study (조심법(調心法)을 통한 혈위의 체표온도변화 관찰 : Pilot Study)

  • Lee, Hwa-Jin;Chae, Youn-Byoung;Park, Hi-Joon;Baik, You-Sang;Yi, Seung-Ho;Lee, Hye-Jung
    • Korean Journal of Acupuncture
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    • v.24 no.3
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    • pp.55-65
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    • 2007
  • Qi intention. Temperature variations on the outer skin above measured at acupuncture points, PC8, LI4, and ST7. Results : The change of temperature in PC8 of the Qigong trainees were significantly higher than that of non-trainees ($0.97{\pm}0.20$ vs. $0.45{\pm}0.10$ respectively, p< 0.05 ). The change of temperature of the other acupoints areas was not significantly different between the two groups. Conclusions : Qi intention resulted in temperature change at the outer skin on the specific acupoints.

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Effects of Working Fuel Temperature on Injection Characteristics of Bypass Type Piezo Injector (작동 연료온도가 Bypass type 피에조 인젝터의 분사 특성에 미치는 영향)

  • Cho, Insu;Lee, Jinwook
    • Journal of ILASS-Korea
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    • v.24 no.2
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    • pp.66-72
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    • 2019
  • Diesel vehicles suffer from poor starting and running problems at cold temperatures. Diesel vehicles have the characteristic that CO and PM are reduced or similarly discharged when going from low temperature to high temperature. In this study, a bypass type piezo injector for electronic control based common rail injection system was used. Numerical analysis using injector drive analysis model was performed to analyze injector drive and internal fuel flow characteristics according to fuel temperature change. The results show that the rate of density change due to the fuel temperature is proportional, and that the effect of the kinematic viscosity is relatively large between $-20^{\circ}C$ and $0^{\circ}C$. Comparing the results of temperature condition at $0^{\circ}C$ and $20^{\circ}C$, it is considered that the viscosity is more correlated with the needle displacement than the pressure chamber of the delivery chamber.

The Relationships between Temperature Changes and Mortality in Seoul, Korea (서울시의 기온변화와 사망자수 간의 관련성 연구)

  • Lee, Sa-Ra;Kim, Ho;Yi, Seung-Muk
    • Journal of Environmental Health Sciences
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    • v.36 no.1
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    • pp.20-26
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    • 2010
  • Temperature change has been shown to affect daily mortality even though different analytical methods produce different results. The effect of air pollution on the relationship between the temperature and the mortality is not large, although differences exist between temperature models. The aim of this study was to examine how the temperature change affected the daily mortality in Seoul by comparing the results from the temperature model using two study periods: one from 1994 to 2007 and the other from 1997 to 2007. Generally mean temperature, minimum temperature and Q10 temperature was derived as an optimal model, even though there are differences between age and cause of death. The analysis of threshold using total mortalities in all ages from 1994 to 2007 and from 1997 to 2007 showed that the number of the deaths increased 7.02% (95% CI: 6.06~7.98) and 2.51% (95% CI: 1.83~3.19), respectively as the mean temperature increased $1^{\circ}C$ from a threshold temperature of $27.5^{\circ}C$ and $25.7^{\circ}C$ respectively. These results indicated that the temperature has less effect on the number of death than does an extreme heat wave period.