• The KIPS Transactions:PartD
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• v.10D no.6
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• pp.885-896
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• 2003

The typws of service using location Information are being various and extending their domain as wireless internet tochnology is developing and its application par is widespread, so it is prospected that LBS(Location-Based Services) will be killer application in wireless internet services. This location information is basic and high value-added information, and this information services make prior GIS(Geographic Information System) to be useful to anybody. The acquisition of this location information from moving object is very important part in LBS. Also the interfacing of acquisition of moving object between MODB and telecommunication network is being very important function in LBS. After this, when LBS are familiar to everybody, we can predict that LBS system load is so heavy for the acquisition of so many subscribers and vehicles. That is to say, LBS platform performance is fallen off because of overhead increment of acquiring moving object between MODB and wireless telecommunication network. So, to make stable of LBS platform, in this MODB system, acquisition of moving object location par as reducing the number of acquisition of unneccessary moving object location. We study problems in acquiring a huge number of moving objects location and design some acquisition model using past moving patternof each object to reduce telecommunication overhead. And after implementation these models, we estimate performance of each model.

• Journal of the Korean GEO-environmental Society
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• v.13 no.12
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• pp.5-16
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• 2012

The second scientific antarctic station of South Korea is under construction at Terra Nova Bay located in eastern Antarctica. Ground condition in the Antarctica is frozen in general, but there are seasonal frozen grounds with active layers sporadically. When the active layer is frozen, frost heaving occurs that might cause the differential movement of frozen ground and the failure of structures. Therefore, it is necessary to determine the frost heaving susceptibility of soils at Terra Nova Bay before starting antarctic station construction. This study presents experimental investigation of the frost heaving susceptibility of soil samples with variation of particle sizes and unfrozen water contents. The soil samples were taken from five different locations at Terra Nova Bay and physical properties, unfrozen water content, and frost heaving tests were performed. For the frost heaving tests, soil specimens were frozen with constant freezing temperatures at the top and with drainage at the bottom in order to stimulate the frost heaving. The frost heaving tests provide volume expansion, volumetric strain, and heaving rate which can be used to analyze the relationship between the frost heaving vs. particle size and the frost heaving vs. unfrozen water content. Experimental results show that the more the fine contents exist in soils, the more frost heaving occurs. In addition, the frost heaving depends on unfrozen water content. Experimental data can be used to evaluate the frost heaving susceptibility of soils at the future construction site in the Antarctica.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.4
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• pp.457-463
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• 2012

Current refrigerators are designed to have thin doors and walls to facilitate user convenience and increase inner storage space. However, the thin doors and walls gives rise to the problem of dew generation on the outer surface of a refrigerator due to a large critical temperature difference between the outer wall and the room air; So far, an electric heater is commonly used for making the dew to evaporate; in this case, the heater inevitably requires additional electrical power. We propose a new approach to reduce the dew generation in a refrigerator by redesigning the gasket and varying the thickness of the inner case of the refrigerator. The results of simulations performed in this study indicate that the surface temperature in the region where dew was generated was increased by approximately $0.39{\sim}3.07^{\circ}C$ without the use of a heater.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.3
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• pp.93-101
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• 2017

The distribution of inter-annual variation in temperature would help evaluate the likelihood of a climatic risk and assess suitable zones of crops under climate change. In this study, we evaluated two methods to estimate the standard deviation of temperature in the areas where weather information is limited. We calculated the monthly standard deviation of temperature by collecting temperature at 0600 and 1500 local standard time from 10 automated weather stations (AWS). These weather stations were installed in the range of 8 to 1,073m above sea level within a mountainous catchment for 2011-2015. The observed values were compared with estimates, which were calculated using a geospatial correction scheme to derive the site-specific temperature. Those estimates explained 88 and 86% of the temperature variations at 0600 and 1500 LST, respectively. However, it often underestimated the temperatures. In the spring and fall, it tended to had different variance (e.g., increasing or decreasing pattern) from lower to higher elevation with the observed values. A regression analysis was also conducted to quantify the relationship between the standard deviation in temperature and the topography. The regression equation explained a relatively large variation of the monthly standard deviation when lapse-rate corrected temperature, basic topographical variables (e.g., slope, and aspect) and topographical variables related to temperature (e.g., thermal belt, cold air drainage, and brightness index) were used. The coefficient of determination for the regression analysis ranged between 0.46 and 0.98. It was expected that the regression model could account for 70% of the spatial variation of the standard deviation when the monthly standard deviation was predicted by using the minimum-maximum effective range of topographical variables for the area.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.4
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• pp.261-265
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• 2003

Cold air accumulation plays a critical role in formulating daily minimum temperature in complex terrain on radiative cooling nights, and spatial interpolation can be improved by accommodating this important topoclimatic variable. Little is known about the spatial scale for computing cold air accumulation which influences daily minimum temperature. Air temperature was measured at 10-minute intervals during September 2002- February 2003 at eight locations within a 1 by 1 km hilly orchard area. Minimum temperature data for suspected radiative cooling nights were collected, and the deviations from reference observations at a near-by KMA automated weather station were calculated. A digital elevation model with a 10m cell size was used to calculate the cold air accumulation at 8 locations. Zonal averages of the cold air accumulation were computed for each location by increasing the cell radius from 1 to 10. Temperature deviations were regressed to a common logarithm of the smoothed averages of cold air accumulation to derive a linear relationship between the local temperature deviation and the site topography. The highest coefficient of determination ($r^2$ = 0.78) was found at a cell radius of 5, which corresponds to an approximately 1 ha boundary surrounding the point of interest.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.3
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• pp.209-215
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• 2007

To improve the accuracy of frost warning system for pear orchard in a complex terrain in Naju area, the daily minimum temperature forecasted by Korea Meteorological Administration (KMA) was interpolated using a regional climate model based on topoclimatic estimation and optimum scale interpolation from 2004 to 2005. Based on the validation experiments done for three pear orchards in the spring of 2004, the results showed a good agreement between the observed and predicted values, resulting in improved predictability compared to the forecast from Korea Meteorological Administration. The differences between the observed and the predicted temperatures were $-2.1{\sim}2.7^{\circ}C$ (on average $-0.4^{\circ}C$) in the valley, $-1.6{\sim}2.7^{\circ}C$ (on average $-0.4^{\circ}C$) in the riverside and $-1.1{\sim}3.5^{\circ}C$ (on average $0.6^{\circ}C$) in the hills. Notably, the errors have been reduced significantly for the valley and riverside areas that are more affected by the cold air drainage and more susceptible to frost damage than hills.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.139-139
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• 2003

원예작물은 수확 후 여러 가지 요인에 의해 품질이 저하되어 상품성을 잃게되는데, 특히 수확 후 품온상승에 의해 호흡작용이 왕성해져 품질변화를 촉진하게 된다. 그러므로 수확 후 품온을 가능한 한 빠르게 낮추어 신선도를 유지하기 위한 예냉, 저온저장, 저온수송기술등 저온유통시스템을 활용하는 것이 매우 필요하다. 저온유통시스템을 효과적으로 활용하기 위해서는 냉기의 순환이 원활하여 냉각효율이 좋고 파손의 위험과 물류비용을 줄일 수 있는 포장상자의 구조에 대한 연구가 필요하다. 포도, 방울토마토, 참외의 소비형태는 핵가족화와 더불어 신선 고품질의 농산물을 소량 구매하는 소비패턴으로 변화하면서 저온유통 및 소포장을 위한 포장형태의 개선이 요구되고 있다. 따라서 예냉.저온유통에 적합한 포장상자를 개발하기 위하여 연구소, 농협중앙회, 상자제작회사, 포장디자인 업체, 산지농협 작목반이 개발협의체를 구성하여 참외, 포도, 방울토마토의 저온유통용 골판지 상자를 개발하여 압축강도 및 냉각시험을 실시하여 소비지에 시범 보급하였다. 1. 참외 포장상자는 3kg용 상부 개방형 골판지상자로써 손잡이를 부착하고, 포장상자 상부에 덮개용 필름을 부착하였다. 제작된 상자의 압축강도는 저온유통 후 에도 안전압축강도 이상인 343kgf의 압축강도를 나타냈고, 냉각효율도 기존상자에 비하여 높게 나타났다. 또한 개발된 상자를 사용하여 시중에 출하할 경우 기존 5kg 상자에 비하여 8%이상의 부가가치를 높일 수 있었다. 2. 포도 포장상자는 소비자 기호도를 충족하고 다층적재시 손상을 방지하기 위하여 내용물을 1단 적재하고 상자를 개방형으로 하여 덮개용 필름을 부착하므로써 소비자가 내용물을 확인할 수 있도록 하고, 상자의 압축강도는 소비지까지 유통이 완료된 후 에도 수직압축강도가 400kgf이상으로 안전압축강도 보다 높아 저온에서 안전하게 유통할 수 있었다. 또한 개발된 상자를 사용하여 시중에 출하할 경우 기존 5kg 상자에 비하여 2kg상자는 21%, 4kg상자는 12%이상의 부가가치를 높일 수 있었음. 3. 방울토마토 포장상자는 외포장 상자를 4kg용 상부 개방형 골판지상자를 사용하고, 내포장상자는 500g용 PET용기를 사용하여 1상자에 8개의 내포장상자가 적재될 수 있도록 제작하였다. 제작된 외포장상자의 압축강도는 저온유통후에도 320kgf으로 안전압축강도보다 높게 나타났고, 파랫트 적재효율도 96%이상으로 나타나 물류의 효율성을 높일 수 있었다. 개발된 상자를 사용하여 시중에 출하할 경우 기존 산물형태의 4kg용 상자에 비하여 500g 내포장상자에 출하할 경우 20%이상의 부가가치를 높일 수 있었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.465-473
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• 2018

A cabinet-door integrated finite element model for a built-in side-by-side refrigerator with an ice dispenser and home bar was constructed, and its deformation was analyzed by ANSYS. As loads, the food load in the shelf and baskets, and thermal load occurring during the normal operation condition were considered. From results of the analyses, the door height difference (DHD) and door flatness difference (DFD) between the two doors, and the increase in the gap of the door gasket, which affects the sealing of cool air in the cabinet, were derived. As results of an evaluation of the differences, the DHD and DFD under the assembled condition satisfied the acceptance criteria of the manufacturer. The food and thermal loads increased the DHD and DFD due to thermal deformation, and the DFD increased significantly. In addition, the increase in the gap of door gasket located between the cabinet and doors was derived from the results of displacements under the food and thermal loads. The evaluation showed that the maximum increase in gap appeared at the left edge of the freezing compartment gasket, which satisfied the acceptance criteria of the manufacturer.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.1
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• pp.28-34
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• 2011

This study was carried out to estimate monthly mean of daily maximum and minimum temperature across North Korea at a 30 m grid spacing for a climatological normal year (1971-2000) and the 4 decadal averages (1971-1980, 1981-1990, 1991-2000, and 2001-2010). A geospatial climate interpolation method, which has been successfully used to produce the so-called 'High-Definition Digital Climate Maps' (HD-DCM), was used in conjunction with the 27 North Korean and 17 South Korean synoptic data. Correction modules including local effects of cold air drainage, thermal belt, ocean, solar irradiance and urban heat island were applied to adjust the synoptic temperature data in addition to the lapse rate correction. According to the final temperature estimates for a normal year, North Korean winter is expected colder than South Korean winter by $7^{\circ}C$ in average, while the spatial mean summer temperature is lower by $3^{\circ}C$ than that for South Korea. Warming trend in North Korea for the recent 40 years (1971-2010) was most remarkable in spring and fall, showing a 7.4% increase in the land area with 15 or higher daily maximum temperature for April.

• Journal of the Korean association of regional geographers
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• v.16 no.4
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• pp.339-354
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• 2010

In this study, diurnal and intra-seasonal variations of summertime temperature lapse rate (TLR) by synoptic weather conditions in a mountainous basin are examined based on hourly temperature data observed in 2009 summer at an Automatic Weather Station (AWS) network deployed in Haean basin (called Punch Bowl), Yanggu in the Republic of Korea. Summertime average TLR between the top and bottom of the basin is $-0.53^{\circ}C$/100m. Due to its diurnal variations, TLR shows the lowest by $-0.25^{\circ}C$/100m at 6AM, while it maximizes up to $-0.85^{\circ}C$/100m between 4PM~5PM. Comparisons of daily average TLRs by synoptic weather patterns reveal that the magnitude of TLRs is greatest in the order of rainy days ($-0.63^{\circ}C$/100m), heavy rainfall days ($-0.53^{\circ}C$/100m), partly cloudy days ($-0.47^{\circ}C$/100m), and sunny days ($-0.39^{\circ}C$/100m). At dawn on sunny days in summer, strong cooling pools accompanying temperature inversion layers are formed within the basin, while on heavy rainfall days, warming pools are observed due to relatively low TLRs associated with the reduction of surface radiation cooling by clouds.