• Title/Summary/Keyword: CHANGE OF TEMPERATURE

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A Study of the Change of Temperature on Brake Disk Surface during the Service and The Fatigue Characteristic of disk material due to Temperature (철도차량 운행중 제동디스크의 표면 온도변화 및 디스크 재료의 온도변화에 따른 피로특성 연구)

  • Kim, J.H.;Goo, B.C.;Suk, C.S.
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.792-797
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    • 2007
  • This study investigates the change of the temperature and fatigue property of the braking disk (GC25-30 material) for the railway vehicle. The average temperature is measured about $100^{\circ}C$ and the maximum temperature is measured over $200^{\circ}C$ by non-contact sensor from Seoul to Chun-an. In the $20^{\circ}C-300^{\circ}C$. The Fatigue tests did for new and used disk specimens. The fatigue test results of new disk specimens were similar due to the temperature change. But the compare of specimens between new disk and old disk, The fatigue life of old disk specimens was smaller than new disk specimens about 10%.

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Analysis of Air Temperature Change Distribution that Using GIS technique (GIS 기법을 이용한 대기온도 변화 분포 분석)

  • Jung, Gyu-Young;Kang, In-Joon;Kim, Soo-Gyum;Joo, Hong-Sik
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.395-397
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    • 2010
  • AWS that exist in Pusan is watching local meteorological phenomena established in place that the weather observatory does not exist by real time, and is used usefully to early input data of numerical weather forecasting model. I wished to display downtown of Pusan and air temperature change of peripheral area using this AWS data. Analyzed volatility using AWS observation data for 5 years to recognize air temperature change of Pusan area through data about temperature among them. Drew air temperature distribution chart by season of recapitulative Pusan area applying IDW linear interpolation with this.

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A Study on the Conducting Behavior of La-Ca-Mn-O in the vicinity of Phase Transition Temperature (임계점 부근에서 LCMO의 전도 특성에 대하여)

  • 송하정;김우진;권순주
    • Journal of the Korean Magnetics Society
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    • v.8 no.4
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    • pp.179-184
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    • 1998
  • Colossal magnetoresistance is closely related to (but is not) the abrupt change of electrical resistivity in the vicinity of Curie temperature, which is caused by the temperature dependent paramagnetic-ferromagnetic phase transition and concurrent change of electrical conducting mechanism. A resistivity-temperature equation is presented to fully describe the overall behavior, especially the abrupt change. The main ingredients of the equation are a simple effective media theory and a function for the temperature dependent fraction of ferromagnetic phase. The model fits very well to the measured resistivity-temperature curve of $La_{0.7}Ca_{0.3}MnO_3$.

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A study on the short-term load forecasting expert system considering the load variations due to the change in temperature (기온변화에 의한 수요변동을 고려한 단기 전력수요예측 전문가시스템의 연구)

  • Kim, Kwang-Ho;Lee, Chul-Heui
    • Journal of Industrial Technology
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    • v.15
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    • pp.187-193
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    • 1995
  • In this paper, a short-term load forecasting expert system considering the load variation due to the change in temperature is presented. The change in temperature is an important load variation factor that varies the normal load pattern. The conventional load forecasting methods by artificial neural networks have used the technique where the temperature variables were included in the input neurons of artificial neural networks. However, simply adding the input units of temperature data may make the forecasting accuracy worse, since the accuracy of the load forecasting in this method depends on the accuracy of weather forecasting. In this paper, the fuzzy expert system that modifies the forecasted load using fuzzy rules representing the relations of load and temperature is presented and compared with a conventional load forecasting technique. In the test case of 1991, the proposed model provided a more accurate forecast than the conventional technique.

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Volume Change Caused from the Moisture Change in the Limestone Material Pressured under High Temperature (고온을 받은 석회암 골재의 습도경시변화에 따른 체적거동)

  • Feng, Hai-Dong;Son, Ho-Jung;Heo, Young-Sun;Han, Min-Cheol;Yang, Seong-Hwan;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.11a
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    • pp.111-113
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    • 2011
  • This study investigated about how much the limestone's volume was changed as time passed while maintaining a certain level of moisture condition in the limestone material for concrete under high temperature. The result is summarized as follows: It was appeared that the limestone material under high temperature emitted some CO2 resulting from the decarboxylation, so that as the heating temperature was increased, the limestone's length change rate was decreased. In the leave time change after heating the stone, the both conditions of 50% and 100% made the limestone create Ca(OH)2 using some H2O. So it was appeared that as time passed, the limestone's length change rate first increased because of its volume expansion, but the rate was reduced after the limestone material was crumbled.

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Pressure and temperature change in air cylinders in charged or discharged case

  • Takeuchi, Masaaki;Kagawa, Toshiharu;Nomura, Naoki
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10b
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    • pp.298-301
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    • 1993
  • In pneumatic systems the temperature changes during operation owing to air compression or expansion, friction of air movement and friction between solid interface. The temperature change usually ha undesirable influence on process. To attain higher quality of pneumatics, studies in thermo-fluid dynamics is needed. This paper presents experimental results anti theoretical analysis on the temperature change by air charge and discharge to cylinders, which has no piston yet. The temperature increase by charge shows a strong, dependence on axial location along the cylinder, which is proved in theoretical analysis. The temperature decreases by discharge shows rather uniform in the cylinder, which is also proved by theory.

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Temperature-dependent Morphology of Self-assembled InAs Quantum Dots Grown on Si Substrates (Si 기판 위에 형성된 InAs 양자점의 열처리에 의한 표면 상태의 변화)

  • Yoo, Choong-Hyun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.10
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    • pp.864-868
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    • 2007
  • Effect of high-temperature annealing on morphology of fully coherent self-assembled InAs quantum dots' grown on Si (100) substrates at $450^{\circ}C$ by atmospheric pressure metalorganic chemical vapor deposition(APMOCVD) was investigated by atomic force microscopy(AFM). When the dots were annealed at 500 - 600$^{\circ}C$ for 15 sec - 60 min, there was no appreciable change in the dot density but the heights of the dots increased along with the reduction in the diameters. In segregation from the InAs quantum dots and/or from the 2-dimensional InAs wetting layer which was not transformed into quantum dots looked responsible for this change in the dot size. However the change rates remained almost same regardless of annealing time and temperature, which may indicate that the morphological change due to thermal annealing is done instantly when the dots are exposed to high temperature annealing.

Prediction of Air Movement and Temperature Distribution at Different Store Methods Using 3-D CFD Simulation in Forced-Air Cooling Facility

  • Yang, G.M.;Koh, H.K.
    • Agricultural and Biosystems Engineering
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    • v.3 no.2
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    • pp.65-72
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    • 2002
  • Temperature is the most influential environment parameter which affects the quality change of agricultural products in cold storage. Therefore, it is essential to keep the uniform temperature distribution in the storage room. This study was performed to analyze the air movement and temperature distribution in the forced recirculating cold storage facility and to simulate optimum storage method of green groceries using 3-D CFD(three dimensional computational fluid dynamics) computer simulation which applied the standard $textsc{k}$-$\varepsilon$ turbulence model and FVM(finite volume method). The simulation was validated by the experimental results for onion storage and the simulation model was used to simulate the temperature and velocity distribution in the storage room with reference to the change of storage method such as location of storage, no stores, bulk storage, and pallet storage. In case of no stores, internal airflow was circulated without stagnation and consequently air movement and temperature distribution were uniform. In case of bulk storage, air movement was stagnated so much and temperature distribution of onion was not uniform. Furthermore, the inner temperature of onion roses more than the initial temperature of storage. In case of pallet storage, air movement and temperature distribution of onion were so uniform that the danger of quality change was decreased.

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