• Asian Journal of Turfgrass Science
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• v.17 no.1
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• pp.45-51
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• 2003

The purpose of this study was to find out how different types of land use around green belts affect temperature decrease effects. For this, temperatures within and outside of green belts were measured. Based on the collected data, the study analyzed the land cover status and temperatures within green belts, temperature decrease effects and the range of effects around green belts, and the correlation between trees and temperature decrease effects by way of regression analysis. As a result, areas of the high temperature within green belts were formed on paved surfaces, whereas areas of low temperature were formed around forests or water surfaces. In addition, deviation was bigger in the highest temperature than the lowest one for areas of Leeward around green belts, but in general, there was a tendency that temperature became low near to green belts. As for the relation between land cover rate and temperature, what was effective to temperature decrease included forests, pasture and water surfaces. On the other hand, the effects of temperature decrease varied depending on increase or decrease of land cover rates. As for the influence of the different land use types around green belts on temperature decrease effects, the Shakuzi Park showed relatively stronger effects than the Ageomaruyama Park.

• Asian Journal of Atmospheric Environment
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• v.10 no.4
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• pp.179-189
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• 2016

Here we evaluated the effect of using water retentive pavement or WRP made from fly ash as material for main street in a real city block. We coupled computational fluid dynamics and pavement transport (CFD-PT) model to examine energy balance in the building canopies and ground surface. Two cases of 24 h unsteady analysis were simulated: case 1 where asphalt was used as the pavement material of all ground surfaces and case 2 where WRP was used as main street material. We aim to (1) predict diurnal variation in air temperature, wind speed, ground surface temperature and water content; and (2) compare ground surface energy fluxes. Using the coupled CFD-PT model it was proven that WRP as pavement material for main street can cause a decrease in ground surface temperature. The most significant decrease occurred at 1200 JST when solar radiation was most intense, surface temperature decreased by $13.8^{\circ}C$. This surface temperature decrease also led to cooling of air temperature at 1.5 m above street surface. During this time, air temperature in case 2 decreased by $0.28^{\circ}C$. As the radiation weakens from 1600 JST to 2000 JST, evaporative cooling had also been minimal. Shadow effect, higher albedo and lower thermal conductivity of WRP also contributed to surface temperature decrease. The cooling of ground surface eventually led to air temperature decrease. The degree of air temperature decrease was proportional to the surface temperature decrease. In terms of energy balance, WRP caused a maximum increase in latent heat flux by up to $255W/m^2$ and a decrease in sensible heat flux by up to $465W/m^2$.

• Journal of Power System Engineering
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• v.9 no.4
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• pp.137-142
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• 2005

The effects of temperature and initial crack length on impact fracture behavior of side plate material of 35 ton class FRP ship, which are composed by glass fiber and unsaturated polyester resin, were investigated. Impact fracture toughness of GF/PE composites displayed maximum value when the temperature of specimen is room temperature and $50^{\circ}C$, and with decrease in temperature of specimen, impact fracture toughness decreased. Impact fracture energy of GF/EP composites decreased with increase in initial crack length of specimen, and this value decreased rapidly when the temperature of specimen is lowest, $-25^{\circ}C$,. It is believed that sensitivity of notch on impact fracture energy were increased with decrease in temperature of specimen. As the GF/EP composites exposed in low temperature, impact fracture toughness of composites decreased gradually owing to the decrease of interface bonding strength caused by difference of thermal expansion coefficient between the glass fiber/polyester resin. Further, decrease of interface bonding strength of composites with decrease in specimen temperature was ascertained by SEM photograph of impact fracture surface.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.3
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• pp.188-193
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• 2009

The present study was undertaken to evaluate the effect of temperature on the results of Charpy impact test for glass fiber reinforced polyurethane(GF/PUR) composites. The Charpy impact test were conducted in the temperature range from -50$^{\circ}$ to 50$^{\circ}$. The impact fracture toughness of GF/PUR composites was considerably affected by temperature and it was shown that the maximum value was appeared at room temperature. It is believed that sensitivity of notch on impact fracture energy were increased with decrease in temperature of specimen. As the GF/PUR composites exposed in low temperature, impact fracture toughness of composites decreased gradually owing to the decrease of interface bonding strength caused by difference of thermal expansion coefficient between the glass fiber/polyurethane resin. And decrease of interface bonding strength of composites with decrease in specimen temperature was ascertained by SEM photographs of Charpy impact fracture surface.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.10-19
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• 2002

In order to investigate relation between park scale and temperature decrease in and near parks, temperature distribution was observed and was analyzed in four parks of different scales. Relation between the temperature decrease and ratio of green coverage was also analyzed by using regression analysis. Lower temperature was observed in and near the parks and larger cooling effect was implicated near the larger parks. The result of regression analysis showed that the increase of green coverage ratio lends the decrease of the temperature in the parks. The degree of the temperature decrease varied according to the types of the coverage.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.2
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• pp.173-178
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• 2007

This paper is to establish an appropriate model for predicting the temperature decreases in the batch transferred from the refining process to the caster in steel-making companies. Mathematical modeling of the temperature decreases between the processes is difficult, since the reaction mechanism by which the temperature changes in a molten steel batch is dynamic, uncertain and complex. Three soft computing techniques are examined using the same data, namely the multiple regression, fuzzy regression, and neural net (NN) models. To compare the accuracy of these three models, a limited number of input variables are selected from those variables significantly affecting the temperature decrease. The results show that the difference in accuracy between the three models is not statistically significant. Nonetheless, the NN model is recommended because of its adaptive ability and robustness. The method presented in this paper allows the temperature decrease to be predicted without requiring any precise metallurgical knowledge.

• Journal of Applied Reliability
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• v.2 no.1
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• pp.1-14
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• 2002

High temperature operating test, temperature humidity test and temperature cycling were performed at various test levels for solid aluminum electrolyte capacitors made by domestic manufacturing company and foreign advanced manufacturing company. It was found that main failure mode of solid aluminum electrolyte capacitors was the decrease of their capacitances. The decrease of their capacitances has the same pattern in these tests. Test result for comparison of characteristics between domestic products and foreign advanced products shows that domestic products have the shorter lifetime and their capacitances decrease more rapidly in high temperature operating test and temperature humidity test. Also in these tests, accelerated tests for high temperature operating test and temperature humidity test were developed.

• Structural Engineering and Mechanics
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• v.65 no.3
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• pp.343-348
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• 2018

This paper reports mechanical behavior of recycled fine aggregate concretes after high temperatures. It is found that compressive strength of recycled fine aggregate concretes decline significantly as the temperature rises. The elastic modulus of recycled fine aggregate concretes decreases with the increase in temperature, and the decrease is much quicker than the decrease in compressive strength. The split tensile strength of recycled fine aggregate concrete decrease as the temperature rises. Through the regression analysis, the relationship of the mechanical behavior with temperature are proposed, including the compressive behavior, elastic modulus and split tensile strength, which are fitting the test data.

• The Korean Journal of Mycology
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• v.34 no.2
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• pp.88-91
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• 2006

Attempts were made to investigate the conditions of mycelia of one low-temperature type strain and one high-temperature type strain of shiitake showing poor fruit-body formation in bed-log, and to survey harmful microorganisms formed on the log surface in Gapyung County, Korea. When tested the growing ability of mycelia, the low-temperature type strain showed ca. 1.1% decrease compared with preserved original strain. And, the high-temperature type one showed ca. 8.0% decrease. The growth of isolated mycelia was tested in sawdust medium. The high-temperature type strain showed ca. 10.8% decrease compared with original strain, and the low-temperature type one showed ca. 25.1% decrease. Weight reduction rate was investigated. The high-temperature strain showed ca. 20.1% decrease and the low-temperature one ca. 19.0%. When compared with non-treatment, original high-temperature type strain showed 107.0% decrease, the isolated high-temperature type strain 49.5%, original low-temperature type one 85.4%, isolated low-temperature type one 50.0%. As the results of confrontation culture, the high-temperature type strain and the low-temperature type one were same as the original ones, respectively. And, in the bed-logs, Hypoxylon truncatum, Coriolus versicolor, Inonotus xeranticus, Daedaleopsis tricolor, Graphostroma platystoma, two species of Myxomycetes, Trichoderma sp. Hypoxylon fragiforme, H. howeianum, and Nitschkia confertula were observed as harmful microorganisms, and the bed-logs were not in good condition.

• Journal of Welding and Joining
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• v.32 no.1
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• pp.66-70
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• 2014

In Ti active brazing of YSZ to STS 430 using Ag-Cu Filler Metal, the effect of Ti contents on the shear bonding strength were investigated together with the effect of brazing temperature and holding time. The addition of Ti in Ag-Cu Filler Metal increased the bonding strength up to 4.68% Ti, followed by the decrease with further addition. This seems to be caused by formation of TixOy at the reaction layer. Brazing temperature was optimized at $960^{\circ}C$ among a given temperature ranges. The addion of Sn to Ag-Cu filler metal brought the decrease of its melting temperature its melting temperature without a significant decrease of bonging strength.