• Title/Summary/Keyword: heat-wave data

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A Numerical Simulation of the Interannual and Decadal Variations of the Northern Lower Stratospheric Polar Temperature (북반구 하부성층권 극기온의 경년변화와 수십년주기변화의 수치모의)

  • Choi, Wookap;Kim, Yujin;Kim, Dongjoon
    • Atmosphere
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    • v.19 no.1
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    • pp.79-91
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    • 2009
  • Seoul National University General Circulation Model (SNUGCM) has been run for 100 years to obtain daily temperature and meridional velocity at the Northern lower stratosphere. The model results are compared with the NCEP/NCAR reanalysis data. The polar temperature and the eddy heat flux from the model show that the model-produced climatology has well-known cold bias and weaker planetary wave activities. The model climatology also has a lag in the seasonal evolution. The relationship between the model-produced polar temperature and the eddy heat flux is investigated with respect to the interannual and decadal time scales. The interannual variation of the polar temperature is related with both total and stationary eddy heat flux in January and March, which is in agreement with observation. The model, however, does not reproduce the relationship between the decadal variation of the polar temperature and transient eddy heat flux, which is revealed in the observed data.

A Study on the Heat Budget in the South Eastern Area of the Yellow Sea (황해 남동해역에서의 열수지에 관한 연구)

  • 이현철;안희수
    • 한국해양학회지
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    • v.22 no.4
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    • pp.217-227
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    • 1987
  • The heat budget of the south eastern region (33$^{\circ}$N-36$^{\circ}$N, 120$^{\circ}$E-125$^{\circ}$E) of the Yellow Sea was calculated by using the meteorological and oceanographical data. The sensibly heat, the evaporation heat and the long wave back radiation have annual variation and increases toward south with strong gradient along the Cheju channel in winter, but they all show tendency to decrease toward eastern coastal area in summer. The area is roughly divided into three parts, the central part, the coastal part and the southern part, according to the characteristics ovariation and distribution patterns of the exchanged heats. The amplitude of the annual variation of total heat exchange in the southern part is very large compare to those of the central and coastal part. The studied area is appeared to be heated mainly by the evaporation heat and the sensoble heat, based on the results of this study.

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ANALYSIS OF TEMPERATURE RISE ON THE ROOT SURFACE DURING CONTINUOUS WAVE OF CONDENSATION TECHNIQUE (Continuous Wave of Condensation Technique으로 근관충전시 치근면 온도상승 분석)

  • Kim, Young-Ju;Hwang, Yun-Chan;Kim, Sun-Ho;Hwang, In-Nam;Choi, Bo-Young;Jeong, Young-Jin;Juhng, Woo-Nam;Oh, Won-Mann
    • Restorative Dentistry and Endodontics
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    • v.28 no.4
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    • pp.341-347
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    • 2003
  • This study was conducted to evaluate the temperature rise on the root surface while the root canal is being obturated using continuous wave of condensation technique. Maxillary central incisor was prepared for repeated canal obturation. Ten thermocouples (Omega Engineering Inc., Stanford, USA) were placed at 1 mm increment from the anatomical root apex. The real temperature of Buchanan plugger was recorded before insertion into the root canal. The root canal was obturated with continuous wave of condensation technique as described by Buchanan and the root surface temperature was recorded during obturation at $150^{\circ}C,{\;}200^{\circ}C,{\;}250^{\circ}C{\;}and{\;}300^{\circ}C$ temperature settings of System B HeatSource (Model 1005, Analytic technologies, Redmond, WA, USA). After completion of the temperature recording, the dentinal-cementum thickness at each sites was measured. The data were analyzed using one-way ANOVA followed by Scheffe's test and linear regression test. The results were as follows. 1. When the temperature was set at $150^{\circ}C,{\;}200^{\circ}C,{\;}250^{\circ}C{\;}and{\;}300^{\circ}C$ on the digital display of System B HeatSource, the real temperature of the plugger at the 1mm point from the tip revealed $130.82{\pm}2.96^{\circ}C,{\;}158.00{\pm}5.26^{\circ}C,{\;}215.92{\pm}6.91^{\circ}C{\;}and{\;}249.88{\pm}3.65^{\circ}C$ respectively. 2. The position of 8 mm from the anatomical apex showed the highest temperature increase at each temperature settings and it was significantly higher than those of other positions (p<0.0l). The temperature rise was constantly increased toward coronal portion from apex of the root. 3. The maximum temperature increase on the root surface was $2.37{\pm}0.09^{\circ}C{\;}at{\;}150^{\circ}C{\;}setting,{\;}3.11{\pm}0.12^{\circ}C{\;}at{\;}200^{\circ}{\;}setting,{\;}3.93{\pm}0.09^{\circ}C{\;}at{\;}250^{\circ}C{\;}setting{\;}and{\;}5.69{\pm}0.15^{\circ}C{\;}at{\;}300^{\circ}C$ setting respectively. These results suggest that it be relatively kind to the supporting tissues of the root that the root canal is obturated using continuous wave of condensation technique at $150^{\circ}C,{\;}200^{\circ}C,{\;}250^{\circ}C{\;}and{\;}300^{\circ}C$ temperature settings on digital temperature display of System B HeatSource.

A Study on the Characteristics of Pulse Waves according to Eight Principle Pattern Identification in 500 Women (500명 여성을 대상으로 한 팔강변증에 따른 맥파 특성 연구)

  • Lee, In Seon;Jeon, Soo Hyung;Kang, Chang Wan;Kim, Jong Won
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.35 no.6
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    • pp.274-279
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    • 2021
  • This study was conducted to find objective diagnostic indicators for the Eight Principle Pattern Identification using a pulse wave analyzer. Typology Complexion Pulse and Symptom data from 500 women over the age of 18 were used. Five experts made a diagnosis of Eight Principle Pattern Identification and divided the subjects into 'Yin-Yang', 'Exterior-Interior', 'Cold-Heat', 'Deficiency-Excess' groups. Their pulse waves were measured in the left and right radial arteries, and it was investigated whether there was a significant difference between groups in the pulse wave parameter values. 'Yin' group showed a significantly lower value in the left radial artery for Ener, Emin, EIX, T4T, T4TT parameters and in the Right for T2, T2T, T5. The Vmag, As and Ad parameters were significantly different between the 'Exterior' and 'Interior' groups. 'Heat' group showed a significantly higher value in the right radial artery for RAI/t parameter. 'Deficiency' group showed a significantly higher value in the right radial artery for W, Angl parameters. Through this study, significant pulse wave parameters were found, and they can be used as objective diagnostic indicators for Eight Principle Pattern Identification.

Analytical solution of the Cattaneo - Vernotte equation (non-Fourier heat conduction)

  • Choi, Jae Hyuk;Yoon, Seok-Hun;Park, Seung Gyu;Choi, Soon-Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.5
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    • pp.389-396
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    • 2016
  • The theory of Fourier heat conduction predicts accurately the temperature profiles of a system in a non-equilibrium steady state. However, in the case of transient states at the nanoscale, its applicability is significantly limited. The limitation of the classical Fourier's theory was overcome by C. Cattaneo and P. Vernotte who developed the theory of non-Fourier heat conduction in 1958. Although this new theory has been used in various thermal science areas, it requires considerable mathematical skills for calculating analytical solutions. The aim of this study was the identification of a newer and a simpler type of solution for the hyperbolic partial differential equations of the non-Fourier heat conduction. This constitutes the first trial in a series of planned studies. By inspecting each term included in the proposed solution, the theoretical feasibility of the solution was achieved. The new analytical solution for the non-Fourier heat conduction is a simple exponential function that is compared to the existing data for justification. Although the proposed solution partially satisfies the Cattaneo-Vernotte equation, it cannot simulate a thermal wave behavior. However, the results of this study indicate that it is possible to obtain the theoretical solution of the Cattaneo-Vernotte equation by improving the form of the proposed solution.

TRANSITIONAL FLOW ANALYSIS OVER DOUBLE COMPRESSION RAMP WITH NOSE BLUNTNESS IN SUPERSONIC FLOW (초음속 이중 압축 램프의 앞전 곡률에 따른 천이 유동 해석)

  • Shin, Ho Cheol;Sa, Jeong Hwan;Park, Soo Hyung;Byun, Yung Hwan
    • Journal of computational fluids engineering
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    • v.20 no.4
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    • pp.36-43
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    • 2015
  • Accurate prediction of supersonic transition is required for the heat transfer estimation over supersonic double compression ramp flows. Correlation-based transition models were assessed for a supersonic double ramp problem. Numerical results were compared with experimental data from RWTH Aachen University. A parametric study on the nose bluntness was performed using a selected transition model. As the nose bluntness increases, the boundary layer thickness is increased and the triple point of shock interactions moves downstream. The peak magnitude of the heat transfer is consequently decreased with the nose bluntness.

A Characteristics of a Secondary flow in a Corner Section of Square Duct (정사각덕트의 코너부에서 이차유동 특성)

  • Joung, J.M.;Kim, J.H.;Yoo, Y.T.
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.753-758
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    • 2000
  • Heat engine and fluid machinery in the plant have to linked with various ducts network and the corresponding design have to be concerned about effectiveness and stability of system of plant. To optimum control and design system concerning stability, economization, operating effectiveness we have to exact analysis flow properties of a duct applying to fluid machinery, heat exchanger, cooling machine, air conditioning equipment. therefore, it is necessary to research the duct, heat transfer equipment, for increasing overall effectiveness of air conditioning system by suggesting basic data of the duct resulting from organic research. So we can contribute to technical development of the duct. In case of speeding up the flow rate of the duct, lots of wave velocity components are occurred the value of boundary layer resulting from developing the boundary layer at both walls of duct.

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Heat Stress Assessment and the Establishment of a Forecast System to Provide Thermophysiological Indices for Harbor Workers in Summer (하계 항만열환경정보 제공을 위한 열환경 평가 및 예보시스템 구축)

  • Hwang, Mi-Kyoung;Yun, Jinah;Kim, Hyunsu;Kim, Young-Jun;Lim, Yeon-Ju;Lee, Young-Mi;Kim, Youngnam;Yoon, Euikyung;Kim, Yoo-Keun
    • Journal of Environmental Health Sciences
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    • v.42 no.2
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    • pp.92-101
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    • 2016
  • Objectives: Outdoor workers are exposed to thermally stressful work environments. In this study, heat stress indices for harbor workers in summer were calculated to evaluate thermal comfort based on a human heat balance model. These indices are Physiological Subjective Temperature (PST), Dehydration Risk (DhR), and Overheating Risk (OhR) according to respective stage of cargo work in a harbor. In addition, we constructed a forecast system to provide heat stress information. Methods: Thermophysiological indices in this study were calculated using the MENEX model (i.e. the human heat balance model), which used as inputs the meteorological parameters, clothing insulation, and metabolic rate for each stage of cargo work in the harbor of Masan over the course of seven days, including a four-day heat wave. The forecast heat stress information constructed for Masan harbor was based on meteorological data supported by the Dong-Nae Forecast from the KMA (Korea Metrological Administration) and other input parameters. Results: According to higher metabolic rate, thermophysiological indices showed a critical level. In particular, PST was evaluated as reaching the 'Very hot' or 'Hot' level during all seven days, despite the heat occurring over only four. It is important in a regard to consider the work environment conditions (i.e. labor intensity and clothing in harbor). On a webpage, the forecast thermophysiological indices show as infographics to be easily understand. This webpage is comprised of indices for both current conditions and the forecast, with brief guidance. Conclusion: Thermophysiological indices show the risk level to health during a heat wave period. Heat stress information could help to protect the health of harbor workers. Further, this study could extend the applicability of these indices to a variety of outdoor workers in consideration of work environments.

Sea Surface Temperature Time Lag Due to the Extreme Heat Wave of August 2016 (2016년 8월 폭염에 따른 표층수온의 지연시간 고찰)

  • Kim, Ju-Yeon;Han, In-Seong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.6
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    • pp.677-683
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    • 2017
  • In this study, we examined responses to Sea Surface Temperature (SST) as the result of an intensive heat wave that took place in August 2016 and the cross correlation between SST and Air Temperature (AT) in August 2016. The data used included the SST of 8 ocean buoys, provided by the National Institute of Fisheries Science, and the AT of AWS near those 8 ocean buoys recorded every hour. To identify an appropriate data period, on FIR filter was applied. Two locations in the south sea were selected to be observed over similar a period, with a high correlation coefficient of about 0.8 and a time lag of about 50 hours between AT and SST. For the yellow sea, due to shallow waters and tidal currents, SST showed a rapid response caused by changes in AT. The east sea showed a negative correlation between AT and SST because of significant water depth and marine environment factors. By identifying the time lag between AT and SST, damage to aquatic organisms can be minimized, and we expect to develop a rapid response system for damage to the fishery industry caused by extreme heat waves.

A Study on Evaluation of Residual Stresses for Rolled Aluminum Plate Using the Critically Refracted Longitudinal(LCR) Wave (LCR 파를 이용한 압연 알루미늄판의 잔류응력 평가에 관한 연구)

  • 김선진;전창환
    • Journal of Ocean Engineering and Technology
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    • v.15 no.3
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    • pp.81-86
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    • 2001
  • Ultrasonic travel-times obtained with the LCR ultrasonic technique have shown an ability to distinguish among three aluminum plates. The 244$\times$150mm thick, but differ in heat treatment. One is fully annealed, the second is quenched and then tempered, and the third is heat-treated to T651 plate, as received plate. Travel-times were obtained at four locations on each side of all plates. The data for both sides of each plate clearly are in very close agreement except location 1 of each plate. In order to show travel-time variation throughout the plate areas, the average travel-time for both sides of each plate were calculated. For Plate 1, the travel-time data were the highest and the data of Plate, the travel-time data were the highest and the data of Plate 2 were upper than Plate 3. Finally, the residual stresses for each plate were measured by X-ray diffraction method. The results showed a good relation. These preliminary results indicate that the LCR Ultrasonic Technique may be not only further developed for use in quality control in the manufacture of rolled aluminum plates but also industry.

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