• Journal of Ecology and Environment
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• v.36 no.1
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• pp.65-71
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• 2013

The concentration of airborne pollen is related to meteorological parameters. The main purpose of this study was to determine the correlation between airborne pollen and meteorological parameters in Ulsan based on sampling from 2010 to 2011. The primary factors of interest were differences in the pollen scattering start date, end date, and peak date, and the fluctuations in pollen concentration. The meteorological parameters that affected the start and peak dates of the pollen season were as follows. For Pinus and Alnus, the dates were correlated with sunshine and an increase in temperature, whereas for Quercus, the dates were correlated with increasing temperature. During the pollen season, Alnus peaked when the temperature was highest and Pinus peaked when the relative humidity was lowest. The concentration of airborne pollen was correlated with meteorological parameters during the sampling period as follows: Pinus, Alnus, and Humulus pollen concentrations were positively correlated with increasing temperature and negatively correlated with rainfall and relative humidity; Humulus pollen concentration was positively correlated with sunshine; and Quercus and Humulus pollen concentrations were positively correlated with wind speed.

• Korean Journal of Remote Sensing
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• v.38 no.1
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• pp.57-72
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• 2022

In this paper, we aimed to examine the flowering dates of cherry blossom and the peak dates of maple leaves in South Korea, by the combination of temperature observation data from ASOS (Automated Surface Observing System) and NDVI (Normalized Difference Vegetation Index) from MODIS (Moderate Resolution Imaging Spectroradiometer). The more recent years, the faster the flowering dates and the slower the peak dates. This is because of the impacts of climate change with the increase of air temperature in South Korea. By reflecting the climate change, our statistical models could reasonably predict the plant phenology with the CC (Correlation Coefficient) of 0.870 and the MAE (Mean Absolute Error) of 3.3 days for the flowering dates of cherry blossom, and the CC of 0.805 and the MAE of 3.8 for the peak dates of maple leaves. We could suppose a linear relationship between the plant phenology DOY (day of year) and the environmental factors like temperature and NDVI, which should be inspected in more detail. We found that the flowering date of cherry blossom was closely related to the monthly mean temperature of February and March, and the peak date of maple leaves was much associated with the accumulated temperature. Amore sophisticated future work will be required to examine the plant phenology using higher-resolution satellite images and additional meteorological variables like the diurnal temperature range sensitive to plant phenology. Using meteorological grid can help produce the spatially continuous raster maps for plant phenology.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.4
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• pp.67-74
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• 2004

As data rate was increased, the conventional burst-mode automatic power control circuit caused errors due to the effort of the mark density variation. To solve this problem we invented a new structured peak-comparator which could eliminate the effect of the mark density variation even in high date rate, and revised the conventional one using it. We proposed a burst-mode automatic power control circuit robust to mark density variations. We found that the peak-comparator in the proposed automatic power control circuit was very robust to mark density variations because it affected very little by the mark density variation in high date rate and in the wide variation range of the reference current and the difference current.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.3
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• pp.225-231
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• 2016

Peak load rate(i.e., maximum daily flow/average daily flow) has not been considered for industrial water demand planning in Korea to date, while area unit method based on average daily flow has been applied to decide capacity of industrial water treatment plants(WTPs). Designers of industrial WTPs has assumed that peak load would not exist if operation rate of factories in industrial sites were close to 100%. However, peak load rates were calculated as 1.10~2.53 based on daily water flow from 2009 to 2014 for 9 industrial WTPs which have been operated more than 9 years(9-38 years). Furthermore, average operation rates of 9 industrial WTPs was less than 70% which means current area unit method has tendency to overestimate water demand. Therefore, it is not reasonable to consider peak load for the calculation of water demand under current area unit method application to prevent overestimation. However, for the precise future industrial water demand calculation more precise data gathering for average daily flow and consideration of peak load rate are recommended.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.3
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• pp.210-218
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• 2018

This study was conducted to examine the influence of different transplanting dates on rice quality and starch properties (morphology and pasting properties) of rice varieties that may be used for the production of rice flour. Three rice flour varieties, 'Seolgaeng', 'Hangaru', and 'Milyang317', were transplanted on May 20, May 30, June 10, and June 20. The peak viscosity decreased with a delay in the transplanting date. However, the amylose content increased with a delay in the transplanting date, whereas that of protein decreased. Amylopectin short-branch chain content increased in the rice varieties that were transplanted on May 30. The morphology of the starch granule of the varieties was determined by SEM. No apparent external difference in the starch granules was observed for the different transplanting dates. These results indicate that the transplanting date influenced the amylopectin structure and pasting properties, which led to changes in the physicochemical characteristics of rice starch.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.713-720
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• 2000

The directional response of strength and deformation on the rocks acting by external loads is called by strength and deformability anisotropy, respectively. Peak strength and its failure criteria of anisotro rocks have been studied and reported. Many authors have investigated in detail the behavior of triaxial peak strength of anisotropic rocks(Jaeger 1960, McLamore & Gray 1967, Hoek & Brown 1980, Ramamurthy & Rao 1985). They concluded that the triaxial strength of anisotropic rocks varies according to the inclination of discontinuity in specimens. And, the minimun triaxial strength occurs in the specmen with 60° of inclination angle ; and specimens with 0° or 90° inclination have maximum triaxial strength. Based on the experimental result, the behavior triaxial strength is investigated. The triaxial compression tests due to the angle bedding plane have been conducted and the material constants, 'm' and 's', cohesion and angle of friction and nonlinear strength parameters to fit for the failure criterion were derived from the regression analysis. And, the experimental date are employed to examine three existing failure criteria for peak strength, provided by Jaeger, McLamore and Hoek & Brown and Ramamurthy & Rao. For a shale, the suitability of the failure criteiria of triaxial peak strength for anisotropic rocks is discussed.

• Geomechanics and Engineering
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• v.21 no.4
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• pp.327-336
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• 2020

Conventional researches on the behavior of fiber-reinforced and unreinforced soils often investigated the failure point. In this study, a concept is proposed in the comparison of the fiber-reinforced with unreinforced sand, by estimating the strength and strength ratio at different levels of strain. A comprehensive program of laboratory drained triaxial compression test was performed on compacted sand specimens, with and without date palm fiber. The fiber inclusion used in triaxial test specimens was form 0.25%-1.0% of the sand dry weight. The effect of the fiber inclusion and confining pressure at 0.5%, 1.0%, 1.5%, 3.0%, 6.0%, 9.0%, 12%, and 15% of the imposed strain levels on the specimen were considered and described. The results showed that, the trend and magnitude of the strength ratio is different for various strain levels. It also implies that, using failure strength from peak point or the strength corresponding to the axial strain of approximately 15% for evaluating the enhancement of strength or strength ratio, due to the reinforcement, may cause hazard and uncertainty in practical design. Therefore, it is necessary to consider the strength of fiber-reinforced specimen at the imposed strain level, compared to the unreinforced specimen.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.908-912
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• 1996

The yearly load forecasting system has been developed for the economic and secure operation of electric power system. It forecasts yearly peak load and thereafter deduces hourly load using the top-down approach. Relative coefficient model has been applied to estimate peak load of a specific date or a specific day of the week. It is equipped with graphic user interface which enables a user to easily access to the system. Yearly average forecasting error may be reduced to $2{\sim}3$(%) only if we can forecast summer-time temperature correctly.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.4
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• pp.235-241
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• 2016

Three different transplanting dates for two rice cultivars grown in Daegu, Republic of Korea, were examined to identify the changes in growth, rice quality, and characteristics of amylopectin. An early transplanting date caused a reduction in the number of panicles in both rice cultivars compared to that in the optimal and late transplanting dates. The 1000-grain weight in the two rice cultivars was significantly increased in the late transplanting date. The rice cultivar tolerant to high temperatures, Donganbyeo, exhibited the lowest milky grain rate in the late transplanting date. The highest rate of head grain was observed in the late transplanting date in both rice cultivars. Regarding the pattern of pasting properties, peak viscosity increased with delayed transplanting dates. With respect to changes in the amylopectin branch-chain length distribution, the amylopectin structure of the translucent Dongan rice cultivar transplanted on April 25 was characterized by a significant increase in A chains with DP > 12, and a decrease in long chains $DP{\geq}37$ compared to that transplanted on June 25. In contrast, the amylopectin structure of the chalky Dongan rice cultivar transplanted on April 25 exhibited further decrease in 13 < DP < 19 than that transplanted on June 25. In the Ungwang rice cultivar, the amylopectin structure of the translucent Ungwang rice cultivar transplanted on April 25 and June 25 was characterized by a significant decrease in the lengths of total amylopectin chains. Furthermore, the amylopectin structure of the chalky Ungwangbyeo rice cultivar transplanted on April 25 was characterized by a significant increase in 7 < DP < 30, while a significant decrease was observed in that transplanted on June 25. These results indicate that the amylopectin structure is altered by different transplanting dates depending on the characteristics of the rice cultivar.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.159-162
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• 1999

This study was carried out to determine the optimum harvest date of unshelled immature peanuts and dried kernels from 60 to 120 days after flowering. Fresh pod yield of spanish-type variety, 'Shaedl-tangkong(SD)' reached a peak of 9,140kg/ ha at 70 (days after flowering(Aug. 13) while that of virginia-type variety, 'Daepoongtangkong(DP)' reached a peak of 8,820kg/ha at 90 days(Sept. 11) after flowering. SD and DP showed maximum fresh kernel yield of 6,090 and 6,470kg/ha at 90 days after flowering (Sept. 11), respectively, while dry kernel yield reached a peak of 3,300 and 3,720kg/ha at 110 days(Oct. 1), respectively. Oil content of SD and DP were the highest at 90 days and 100 days after flowering, respectively and the oil content of two varieties increased rapidly from 60 to 90 days. Tannin content of the seed hull of SD increased continuously until 110 days after flowering while that of DP maximized at 100 days. The tannin content of the two varieties increased rapidly from 60 to 100 days. Total sugar of SD and DP showed highest content at 60 days and 70 days after flowering, respectively and suger content decreased very rapidly until 80 days and after that sugar content kept nearly constant. Oil, tannin and total sugar content of spanish-type SD were higher than those of virginia-type DP.