• KIEAE Journal
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• v.8 no.5
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• pp.11-16
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• 2008

This research has established CFD model on pit's cool-tube system through heat and air movement simulations, of which data was based on experimental and verification. This research work verified the effectiveness of the cool-tube system by analysing temperature, humidity and air current of the actually installed case. Also, we analysed heat transfer through air current simulation and the results are as followings. Firstly, we experiment on temperature, humidity and speed of air currents of the cool tube system with pit space during the month of May (spring). The average exterior temperature was $16.1^{\circ}C$, and $18.2^{\circ}C$ for the pit, $24.7^{\circ}C$ for the compressor room. Secondly, based on measured data of real case, we have analysed heat transfer through air current simulation and verified our proposed model. The actual measurement of average temperature of exhaust air of the pit's area is $19.7^{\circ}C$ with tolerance of $-0.33^{\circ}C{\sim}-0.6^{\circ}C$ compared to above simulations. Thirdly, having verified air current simulation model with formation of 260,000 and 1,000,000 cells, we could get reasonable near values with 260,000 cells. Lastly, the next step of research would be focused on proposing the best possible pit's cool-tube system after analysis of heat transfer of the air current simulation based on verified CFD model.

• The Korean Journal of Ecology
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• v.15 no.1
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• pp.59-65
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• 1992

Pollen analysis to clear vegetational history of korea was carried out on the deposite taken from the pit of the miruksa site, south-western korea(36o00'18'N, 127o1'12'E, 10m in alt.). This area has been known as the cool temperate zone(southern zone) according to yim and kira(1975). But, now we can not found the original vegetation because the area has been disturbed severely and almost area changed to cultivated land.the area is one of the most developd area in early agricultural stage of korea. By the pollen diagram, three local pollen zones are distinguished in this site, bottom to surface, as following. is-Ⅰ :pinus-quercus zone (140∼120 cm, sample 1 and 2) is-Ⅱ :ulmus+zelkova zone(120∼84 cm, sample 3∼6) is-Ⅲ :pinus zone(84∼0 cm, sample 7 ∼13) is-Ⅰ is characterized by high values in frequences of pinus, the temperate conifer and quercus the cool temperate oak, and is-Ⅱ zone by the decrease of quercus and increase of ulmus and increase of ulman+zelkova as ravine forest elements, isⅢ zone is characterized by pinus, especially, based on data of sample no.9.

• Fashion & Textile Research Journal
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• v.22 no.5
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• pp.628-638
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• 2020

This study develops a cool-touch functional Dancesport top for middle-aged women by using cool-touch materials in areas where surface temperature becomes high after exercise. The post-exercise surface temperature of the developed research product was compared and analyzed. In addition, subjective evaluation of cool-touch as well as appearance and movement evaluations were performed. The results are as follows. In designing the research product, a detachable neckband was made using highly-preferred hydrated polymer crystals. A material with high moisture absorption speed was also used in F1, S1, under arm and B5, while a material with good thermal conductivity was used in other parts of the bodice. Deodorant tape with antibacterial and deodorant effects was incorporated in the armpit for additional comfort. As for wear evaluation of the research product, significant differences were found in 10 areas using a material with high moisture absorption speed to compare and analyze the post-exercise surface temperatures of the clothing. The temperature difference between the compared top and the research product in the neckband area was 9.16℃, demonstrating clear cool-touch function in using cool-touch material. In the subjective evaluation of cool-touch function, the results showed high scores when asked about the efficiency of the detachable neckband and the ease of movement when wearing the product. In the appearance evaluation, significant differences were found in 11 items, including redundant folds, tightfit, fit, and design line. The overall mean score of the movement evaluation was 4.6, indicating excellent function for movement.

• Fashion & Textile Research Journal
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• v.16 no.2
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• pp.326-332
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• 2014

To develop cool touch feeling fabrics for summer clothing material, it was manufactured several compositions of woven fabrics, having rayon multi-filament yarn (non-twisted) as warp and various kinds of yarn, such as viscose rayon multi-filament yarn (twisted), tencel$^{(R)}$ spun yarn, PET high absorbance quick dry filament yarn, and PET based rayon-like yarn, as weft. After preparing the fabrics, basic properties of the fabrics were investigated, such as air-permeability, tensile strength, absorption rate, drying rate, etc. Also, surface warm / cool sensations of the woven fabrics were assessed by Qmax Warm / Cool Touch Tester. It was observed that the fabrics composed of viscose rayon multi-filament yarn (warp) and PET high absorbance quick dry filament yarn (weft) showed excellent surface cool touch sensation-the highest Qmax value. This is because the fabric having flat shaped PET high absorbance quick dry filament shows the largest contact area with Qmax measuring plate. And, the fabric also showed superior high absorbance and quick dry property as expected. In addition, we treated phase change material (PCM) on the surface of the fabric composed of viscose rayon multi-filament yarn (warp) and PET high absorbance quick dry filament yarn(weft) to improve the cool touch feeling. However, the surface cool touch feeling was impaired by resin treated with PCM during the finishing process.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.3
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• pp.107-113
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• 2003

Ecological control can contribute to the sustainibility of vegetation management systems by reducing the input currently derived from non-renewable fossil energy sources. The use of turfgrass mixtures is an important tool in turf management. Turfgrass mixtures of two or more compatible and adapted species provide improved tolerance to pest and environmental stress, more so than monostands. The objectives of this study were to evaluated turf insects, pests and zoysia large patch control by turgrass mixtures. In April 2001 and 2002, plots were inoculated with 50g of Rhizoctonia solani AG2-2LP inoculum. Inoculum were treated within a 29cm diamater circle at Zoysia japonica, Zoysia japonica, Poa pratenis, or Festuca arundinacea mixtures. After four weeks, disease severity in each plot was determined. plot area visual ratings were assessed visually on a linera 0 to 100%. In August 2001 and October 2002, turf insects and pests in each plot were investigated in 10cm deep soil cores with 8cm diameters using hole cut. Zoysia large patch affected zoysiagrass monostands more severly than zoysiagrass and cool-season turfgrasses mixtures. It was suggested that the barrier effect of cool-season turfgrass suppressed zoysia large patch in the mixture of zoysiagrass and cool-season turfgrasses. Also, warm-season and cool-season turfgrasses mixtures suppressed insect populations more efficiently than warm-season turfgrass monostands.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.1
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• pp.27-37
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• 2013

A roof surface temperature monitoring, utilizing remotely sensed thermal infrared image has been specifically proposed to explore evidential data for heating load in winter by cool roof. The remotely sensed thermal infrared image made it possible to identify area-wide patterns of changing trends of surface temperature according to rooftop color (white, black, blue, green) which cannot be acquired by traditional field sampling. The temperature difference of cool roof having a higher solar reflectance were ranged from $3^{\circ}C$ up to $9^{\circ}C$, compared to the general roofs. It is confirmed that there is a significant potential to the energy saving by introducing the cool roof in a Korean climate since up to $18.46^{\circ}C$ difference in cool roof, compared to the general roofs in summer were already identified in Seoul, South Korea. It is anticipated that this research output could be used as a valuable reference in identifying heating load in winter by cool roof since an objective monitoring has been proposed based on the area-wide measured, fully quantitative performance of remotely sensed thermal infrared image.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.1
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• pp.11-18
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• 2000

Taegu is notorious as hot and dry summer among Korea cities. One of the most important goals of the open space planning is to ameliorate urban climate of the city. The objective of this research is to evaluate the thermal mitigation effect of the cool islands in Taegu metropolitan city. Cool islands of this paper includes parks and rivers surrounded by or adjacent to urbanized areas. Based on the analysis of the thermal band of Landsat TM at May 17, 1997, the thermal mitigation effect of open spaces in the city could be summarized as follows ; Kumho river showed the largest mitigation effect in terms of the width of mitigation zone and temperature difference. Evaporation from wide water surface and evapo-transpiration from riparian grass land could bring into results. Significant mitigation effect of parks covered with forest can be observed. The temperature range of such parks were between 19.05$^{\circ}C$ and 19.44$^{\circ}C$ However, the thermal mitigation effect of Dalsung park and Apsan park was insignificant. The small size and high percentage of hard paving of the former and the relative low density of the residential areas adjacent to the latter could be the main reason. In conclusion, the thermal mitigation effect in urban ope spaces could be detectedby the employment of thermal band data of Landsat TM and GIS buffering technique.

• Asian Journal of Atmospheric Environment
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• v.7 no.1
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• pp.17-24
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• 2013

Fog deposition onto the cool-temperate deciduous forest around Lake Mashu in northern Japan was estimated by the inferential method using the parameterizations of deposition velocity and liquid water content of fog (LWC). Two parameterizations of fog deposition velocity derived from field experiments in Europe and numerical simulations using a detailed multi-layer atmosphere-vegetation-soil model were tested. The empirical function between horizontal visibility (VIS) and LWC was applied to produce hourly LWC as an input data for the inferential method. Weekly mean LWC computed from VIS had a good correlation with LWC sampled by an active string-fog collector. By considering the enhancement of fog deposition due to the edge effect, fog deposition calculated by the inferential method using two parameterizations of deposition velocity agreed with that computed from throughfall data. The results indicated that the inferential method using the current parameterizations of deposition velocity and LWC can provide a rough estimation of water input due to fog deposition onto cool-temperature deciduous forests. Limitations of current parameterizations of deposition velocity related to wind speed, evaporation loss of rain and fog droplets intercepted by tree canopies, and leaf area index were discussed.

• Design & Manufacturing
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• v.16 no.4
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• pp.67-74
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• 2022

Injection molding is a cyclic process comprising of cooling phase as the largest part of this cycle. Providing efficient cooling in lesser cycle times is of significant importance in the molding industry. Recently, lots of researches have been done for rapid cooling of a hot-spot area using CO2 in injection molding. The CO2 flows under high pressure through small, flexible capillary tubes to the point of use, where it expands to create a snow and gas mixture at a temperature of -79℃. The gaseous CO2 removes heat from the mold and releases it into the atmosphere. In this paper, a CO2 cooling module was applied to an injection mold in order to cool a large area cavity uniformly and quickly, and the cooling performance of the injection mold was investigated. The product was a high-curvature molded part with a molding area of 300x100mm. Heat cartridges were installed in a stationary mold, and CO2 cooling module was inserted inside a movable mold. Through structural analysis, it was confirmed that the maximum deformation of mold with CO2 cooling module was 0.09mm. A CO2 feed system with a heat exchanger was used for cooling experiments. The CO2 was injected into the holes on both sides of the supply pipe of the cooling module and discharged through hexagon blocks to cool the mold. It took 5.8 seconds to cool the mold from an average temperature of 140℃ to 70℃. Through the experiment using CO2 cooling module, it was found that a cooling rate of up to 12.98℃/s and an average of 10.18℃/s could be achieved.

• Korean Journal of Remote Sensing
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• v.37 no.6_3
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• pp.1985-1999
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• 2021

The purpose of this study is to apply urban heat island reduction techniques(green roof, cool roof, and cool pavements using heat insulation paint or blocks) recommended by the Environmental Protection Agency (EPA) to our study area and determine their actual effects through a comparative analysis between land cover objects. To this end, the area of Mugye-ri, Jangyu-myeon, Gimhae, Gyeongsangnam-do was selected as a study area, and measurements were taken using a drone DJI Matrice 300 RTK, which was equipped with a thermal infrared sensor FLIR Vue Pro R and a visible spectrum sensor H20T 1/2.3" CMOS, 12 MP. A total of nine heat maps, land cover objects (711) as a control group, and heat island reduction technique-applied land covering objects (180) were extracted every 1 hour and 30 minutes from 7:15 am to 7:15 pm on July 27. After calculating the effect values for each of the 180 objects extracted, the effects of each technique were integrated. Through the analysis based on daytime hours, the effect of reducing heat islands was found to be 4.71℃ for cool roof; 3.40℃ for green roof; and 0.43℃ and -0.85℃ for cool pavements using heat insulation paint and blocks, respectively. Comparing the effect by time period, it was found that the heat island reduction effect of the techniques was highest at 13:00, which is near the culmination hour, on the imaging date. Between 13:00 and 14:30, the efficiency of temperature reduction changed, with -8.19℃ for cool roof, -5.56℃ for green roof, and -1.78℃ and -1.57℃ for cool pavements using heat insulation paint and blocks, respectively. This study was a case study that verified the effects of urban heat island reduction techniques through the use of high-resolution images taken with drones. In the future, it is considered that it will be possible to present case studies that directly utilize micro-satellites with high-precision spatial resolution.