• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.291-297
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• 2013

Automated weather stations were installed at 9 locations with, three different elevations, (i.e., 50m, 100m, and 300m a.s.l.) with different slope and aspect in a small watershed ($50km^2$ area). Air temperature at 1500 LST and solar radiation accumulated for 1100-1500 LST were collected from January to December 2012. Topography of the study area was defined by a $30{\times}30$ m digital elevation model (DEM) grid. Accumulated solar irradiance was calculated for each location with the spatially averaged slope and aspect of surrounding circles with 5, 10, 15, 20, 25, and 30 grid cell radii, respectively. The 1500 LST air temperature from clear sky conditions with zero cloud amount was regressed to the 1100-1500 LST solar irradiance at 9 locations. We found the highest coefficient of determination ($r^2$ = 0.544) at 25 grid cell radius and the temperature variation in this study was explained by Y = 0.8309X + 0.0438, where Y is 1500 LST temperature (in $^{\circ}C$) and X is 1100-1500 LST accumulated solar irradiance (in $MJ/m^2$).

• Journal of Mechanical Science and Technology
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• v.20 no.12
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• pp.2061-2078
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• 2006

The main purpose of this paper is to establish the high temperature structural integrity evaluating procedures for the next generation reactors, which are to be operated at over 500$^{\circ}C$ and for 60 years. To do this, comparison studies of the high temperature structural design codes and assessment procedures such as the ASME-NH (USA), RCC-MR (France), DDS (Japan), and R5 (UK) are carried out in view of the accumulated inelastic strain and the creep-fatigue damage evaluations. Also the application procedures of the ASME-NH rules with the actual thermal and structural analysis results are described in detail. To overcome the complexity and the engineering costs arising from a real application of the ASME-NH rules by hand, all the procedures established in this study such as the time-dependent primary stress limits, total accumulated creep ratcheting strain limits, and the creep-fatigue damage limits are computerized and implemented into the SIE ASME-NH program. Using this program, the selected high temperature structures subjected to two cycle types are evaluated and the parametric studies for the effects of the time step size, primary load, number of cycles, normal temperature for the creep damage evaluations and the effects of the load history on the creep ratcheting strain calculations are investigated.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.77-77
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• 2017

The sensitivities to photoperiod and temperature give guidance to choose an adaptable genotype for specific area in soybean production. However, there is insufficient information about the variation of sensitivities to photoperiod and temperature with wide genetic background. We investigated the sensitivities to photoperiod and temperature using 82 soybean mini core collection lines provided by NIAS gene bank of Japan. The seeds were sown on 28 May and 4 August in 2015, 24 May and 5 August in 2016 at field in Saga, Japan ($33^{\circ}$ 14' 32'' N, $130^{\circ}$ 17' 28'' E) for the early (average photoperiod and temperature: 15.2 h and $25.1^{\circ}C$) and late (13.6 h and $27.2^{\circ}C$) sowing respectively. The plants were also grown in the growth chamber under 12 h photoperiod with three temperature regimes (day/night temperature: $25/18^{\circ}C$, $28/22^{\circ}C$ and $33/28^{\circ}C$). Emergence date, days to first flower were recorded with 10 plants in the field and 2 plants in the growth chamber for each line. The data for daily average temperatures and photoperiodic hours were collected from weather station. The days from emergence to first flower open (DEF) were varied from 23-92 (2015 and 2016) in early sowing whereas 18-68 (2015) and 18-59 (2016) in late sowing. The shortened DEF in late sowing could be caused by both short photoperiod and high temperature in late sowing. However, the accumulated temperatures during emergence to first flower open (ATEF) were less variable in comparison with DEF, suggesting the ATEF is dependent mostly on the photoperiod. The ATEF were found same between early and late sowing in some early flowering lines (e.g. $686.7^{\circ}C$ and $687.6^{\circ}C$ in HEUKDAELIPS, $728.8^{\circ}C$ and $706.3^{\circ}C$ in WILLIAMS'82) which indicated that these would be insensitive to day length. In the growth chamber experiment, the variation in both DEF and ATEF was a little greater at low temperature ($25/18^{\circ}C$) but almost same at middle ($28/22^{\circ}C$) and high ($33/28^{\circ}C$) temperatures. Since the less differences in ATEF were found between the three temperatures, it is suggested that the temperature plays only a quantitative effect on the flower initiation, and the large ATEF in some lines may indicate the stronger photosensitivity even at 12 h or longer juvenile phase. Some lines with the lowest ATEF regardless of growth conditions, such as FISKEBY V, KE 32 (ATEF: 559.6-666.5, 587.7-709.5) might lack the sensitivities to both photoperiod and temperature. The results suggested that soybean genotypes has wider variation in sensitivity to photoperiod, whereas less variation to temperature.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1078-1080
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• 1995

The pulsed electro-acoustic method was used as a nondestructive measurement technique of spare charge distribution in dielectric materials. In our work presented here, we measured simultaneously the space charge distribution and conduction current in the low-density polyethylene samples with elevated temperatures up to $80^{\circ}C$ and electric field up to 20kV/mm. In the temperature less than $50^{\circ}C$, homocharges are mainly accumulated close to the electrodes under DC bias and after grounding. At the temperature exeeds $50^{\circ}C$, heterocharges are accumulated near the opposite electrode under DC bias. However after grounding the upper electrode, this charges immediately disappeared. The conduction current in LDPE at $20^{\circ}C$ and $30^{\circ}C$ was reduced slowly with increasing interval of applied voltage. But as temperature increased, the conduction current tended to increase slowly with the time and the degree of increase is enlarged.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.807-811
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• 2015

This study was conducted to identify the air temperature factors that affect leafing date of mulberry (Morus alba) in Buan, Jeonbuk province. Over the period from 2009 to 2014, the leafing date averaged April 24 (114 Julian days). The earliest leafing date was April 12, in 2014, and the latest leafing date was May 2, in 2011. Yearly variations of daily mean temperature (DMT) and daily maximum temperature (DMxT) were high in the last part of March. There were highly negative correlations between leafing date and degree days of accumulated DMT above 0, 5, and $10^{\circ}C$ in the period from March 1 to April 10. Linear regression equations for estimating the leafing date were y = 153.8 - 0.1886 ${\times}$ ($r^2=0.965^{**}$) and y = 126.2 - 0.2246 ${\times}$ ($r^2=0.825^*$) for the degree days of accumulated DMT above $5^{\circ}C$ in the period from March 1 to April 10 and the last part of March, respectively. Therefore, leafing date of mulberry, which is important for popcorn disease control, is 96.5% predicted by degree days of accumulated DMT above $5^{\circ}C$ in the periods from March 1 to April 10.

• Journal of Environmental Science International
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• v.32 no.5
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• pp.365-374
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• 2023

Eight years (2014-2021) of climate data were collected from an automatic weather observation system installed at the foot of Mt. Geumo in Chilgok, Gyeongbuk. Using these data, we investigated local bio-climatological indices (warmth index, WI; coldness index, CI; and effective accumulated temperature, EAT) of the mountain region adjacent to the Keimyung Dongyeong forest. The study area's WI and CI were 109.3℃ and -11.3℃ per month, respectively, averaged across 8 years. These values are indicative of an evergreen broad-leaved forest in the warm temperate climate zone, suitable for cultivating sweet persimmons and figs. Additionally, EAT in Dongyeong was 2,113.7℃, averaged across 8 years, suitable for growing crops such as corn, soybean, and potato.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.11
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• pp.1105-1114
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• 2010

Ice shapes accumulated on the aircraft surfaces are categorized into rime and glaze ice, which are highly dependent on various parameters such as ambient temperature, liquid water contents (LWC), mean volumetric droplet diameter and freestream velocity. In this study, quantitative analyses on the ice accretion have been attempted in a systematical manner and the key findings are as follows. First, the increase of freestream velocity can cause tremendous change in the ice accumulation such as the growth of ice accretion area, ice heading direction and maximum thickness of ice horn. Second, LWC is found to be linearly proportional to the ice accretion area. Third, the effects of ambient temperature on incoming water mass seem to be relatively small in comparison with LWC and freestream velocity. Finally, it was shown that MVD has only a little influence on ice shapes. However, it may increase the ice accretion area by increasing the droplet impacting range.

• Korean Journal of Weed Science
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• v.30 no.1
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• pp.50-57
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• 2010

This experiment was conducted to investigate seedling emergence of Humulus japonicus in Seoul and Suwon and to predict its seedling emergence in various locations in Korea. Non-linear regression analysis to fit Gompertz model to accumulated seedling emergence of H. japonicus was performed to describe its seedling emergence. Parameter estimates from the non-linear regression and estimated effective accumulated temperature required for its seedling emergence were further used to predict seedling emergence of H. japonicus in 8 major geographical regions of Korea. Seedling emergence of H. japonicus versus effective accumulated temperature was well described by Gompertz model in both Seoul and Suwon. Effective accumulated temperatures required for the first seedling emergence and 50% of the maximum seedling emergence were estimated to be $56.7^{\circ}C$ and $76.3^{\circ}C$, respectively. Therefore, the dates for the first seedling emergence of H. japonicus were predicted to be 21 and 30 March in Daegu and Daejeon, while 4 and 6 April in Suwon and Chuncheon, respectively. The dates reaching 50% of maximum seedling emergence were also predicted to be 25 March in Daegu, while 3, 8 and 9 April in Daejeon, Suwon and Chuncheon, respectively.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.432-437
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• 2022

In this study, strawberries were grown during the two cultivation periods (first: 2020-2021, second: 2021-2022) to analyze the effect of the external light environment and growing degree days (GDD) on crop production. The temperature and humidity during day in a greenhouse in each cultivation period were similarly managed. At night, there was a statistical difference in temperature and humidity in the greenhouse between two periods. The accumulated solar radiation during the first cultivation period was high in September and October. Since January, the accumulated solar radiation during the second cultivation period was high. In the second cultivation period, the initial yield was small because the accumulated solar radiation and GDD was small. But accumulated yields and potential maximum yields in second cultivation period were larger than yields in the first cultivation period as the accumulated solar radiation and GDD increased. The sugar contents of strawberry decreased as GDD increased.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.54 no.2
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• pp.94-100
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• 2005

Abnormal symptoms on operating conditions of power transformer are monitored by a preventive diagnostic system which prevents the sudden power failure in case of quick progress of abnormal situation. The preventive diagnostic system helps plan the proper maintenance method according to the transformer conditions via accumulated data. KEPCO has adopted the preventive diagnostic system at nine of 345kV substations since 1997. Application techniques of the diagnostic sensors were settled, but diagnostic algorithm and practical use of accumulated data are not yet established. To build up the diagnostic algorithm and effective use of the preventive diagnostic system, the reliability of the data which were accumulated in a server computer is very important. This paper describes the data analysis in the server in order to advance the reliability of the accumulated data of the preventive diagnostic system. The principles and data flows of the diagnostic sensors were analyzed, and the data discrepancy between sensors and server were calibrated.