• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.285-293
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• 2018

This study aimed to evaluate the effect of height suppression of cucumber and tomato plug seedlings as affected by mechanical stimulus using brushing as environment-friendly method. Cucumber (Cucumis sativus L. 'Joeunbaekdadagi') and tomato (Solanum lycopersicum L. 'Mini Chal') seeds were sown in 40-cell plug trays ($54{\times}27.5{\times}5cm$) filled with growing medium on Oct. 9, 2017. The cultivation environment in a venlo-type glasshouse was maintained as cultivation temperature range of $15-25^{\circ}C$ and the relative humidity of $50{\pm}10%$. Nontreatment and diniconazole ($7.5mg{\cdot}L^{-1}$) application at 15 days after sowing were used as the control. In addition, brushing treatments in cucumber and tomato were applied interval of 2, 4 or 6 hrs for 15 and 20 days, respectively. Plant height, hypocotyl length, and internode length were inhibited for cucumber and tomato in the diniconazole treatment than in the control. The leaf size was reduced, both cucumber and tomato, while the SPAD increased under the diniconazole treatment. However, stem diameter of cucumber was the thickest in the 2 hrs brushing interval treatment. Fresh weights of shoot and root were the significantly lowest in the diniconazole treatment. Application of brushing improved seedlings quality by promoting dry weights of shoot and root, and compactness of tomato seedlings. The chlorophyll fluorescence of tomato seedlings drastically decreased with 2 hrs treatment, indicating that mechanical stress by brushing treatment. The relative growth rate of tomato seedlings was significantly lower in the diniconazole treatment, but cucumber seedlings were not significantly different in all treatments. As a results, height suppression of cucumber and tomato seedlings was best achievement in the diniconazole treatment by the chemical as growth regulator. In an environment-friendly point of view, however, it is considered that 2 hrs brushing interval treatment can be the applicability for replacing the chemical methods in plug seedling growth of cucumber and tomato.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.363-370
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• 2018

The succulent plants of Echeveria genus are in increasing demand worldwide, but it is difficult to supply good quality young plants throughout the year because propagation efficiencies are depend on cultivar and environmental factors. This study was carried out to investigate the propagation efficiencies of leaf cutting in Echeveria cultivars at different LED light qualities in a closed-type plant factory system. Leaf cuttings cut from stock plants of six difficult-to-propagated cultivars 'Afterglow (AG)', 'Berkeley Light (BL)', 'Mason (MS)', 'Subsessilis Light (SL)', 'Cream Tea (CT)', and 'Ben Badis (BB)' were put into cutting media in the plant factory system maintained at a temperature of $24{\pm}2^{\circ}C$ and relative humidity of $60{\pm}10%$, and watered with over-head irrigation twice a week. Cuttings were irradiated with sole or mixed red (R, 660 nm), blue (B, 450 nm), green (G, 530 nm), and far-red (FR, 730 nm) LEDs as follows: R10, R8+B2, R5+B5, R7+B2+FR1, and R7+B2+G1. PPFD just above the cuttings was $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and photoperiod was 16/8 (light/dark) hours. As a result, propagation efficiencies were dependent on cultivar. Rooting and shooting were relatively easy in 'SL' but shoot formation in 'AG' was very difficult. Light qualities from LEDs also affected plant regeneration. Light conditions with a higher ratio of B, R5+B5, R7+B2+FR1, and R7+B2+G1, promoted shoot formation and growth but inhibited rooting and root growth. R10 and R8+B2 with a higher ratio of R promoted rooting and root growth and inhibited shoot formation and growth of cuttings. In addition, the treatment with FR increased leaf size and biomass of the all plants. Therefore, further studies are needed to investigate the optimum compositions of LED light quality for the improvement of leaf cutting efficiency in difficultto-propagated Echeveria cultivars.

• Korean journal of applied entomology
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• v.14 no.3 s.24
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• pp.111-131
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• 1975

The study has been carried out to investigate the occurrence, damage, characteristics of the pathogen, environmental conditions affecting the disease outbreak, varietal resistance, forecasting, and chemical control of bacterial leaf blight of rice in Korea since 1964. Bacterial leaf blight of rice became a major disease in Korea since 1960. A correlation was found between the annual increase of epidemics and increase of cultivation area of susceptible varieties, Jinheung, Keumnampung etc. Areal damage within the country showed that the more was at southern province, Jeonnam, Gyeongnam and western coast, and at flooded rice paddy. Yield reduction directly related with the amount of infection on upper leaves at heading stage. Fifty per cent of reduction resulted when the lesion area was more than 60 per cent. Less than 20 per cent of lesion area, however, was not affected so much on yield loss One hundred and six isolates collected from all over the country were classified as 8 strains by using 4 different bacteriophages in 1973. It was, however, only two in 1965. There were some specificities on varietal distributions among the strains such as that the Jinheung attacked mainly by strain A, B, C and I, those attack Kimmaze were A, B, H and I. Most strains were found from Tongil except D and E, whereas Akibare was only variety that attacked by strain E. Low temperature, high humidity, heavy rainfall and insutficient daylight favored the disease epidemics. Especially, typhoon and flooding at heading stage were critical factors. The earlier transplanting the more disease was resulted, and more nitrogen fertilizer application accerelated the diseased development in general. The resistance to the disease varied by growing stage of the sane plants. All of recommended varieties in Korea were susceptible to the disease except Norm No. 6 and Sirogane which moderately resistant. The pathogen, Xanthomonas oryzae, was detectable from extract of healthy seedlings that were grown in the field with an heavy infection previous year. The more bacteriophage in irigation water resulted the more disease outbreak, and the existence of more than 50 bacteriophages in 1ml. of irrigation water were necessary to initiate the disease out break. The curves representing occurrence of bacteriophages and disease outbreak were similar with 15 days interval. The survey of bacteriophage occurrence can be utilized in forecasting of the disease two weeks ahead of disease outbreak. Three applications of chemicals, Phenazin and Sangkel, in weekly intervals at the early satage of out-break depressed the symptom development, and increased yield by 20per cent. Proper period for the chemical application was just before the number of bacteriophage reaches 50 in 1ml. of irrigation water.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.23-31
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• 2013

Microwave remote sensing can help monitor the land surface water cycle and crop growth. This type of remote sensing has great potential over conventional remote sensing using the visible and infrared regions due to its all-weather day-and-night imaging capabilities. In this paper, a ground-based multi-frequency (L-, C-, and X-band) polarimetric scatterometer system capable of making observations every 10 min was developed. This system was used to monitor the wheat over an entire growth cycle. The polarimetric scatterometer components were installed inside an air-conditioned shelter to maintain constant temperature and humidity during the data acquisition period. Backscattering coefficients for the crop growing season were compared with biophysical measurements. Backscattering coefficients for all frequencies and polarizations increased until dat of year 137 and then decreased along with fresh weight, dry weight, plant height, and vegetation water content (VWC). The range of backscatter for X-band was lower than for L- and C-band. We examined the relationship between the backscattering coefficients of each band (frequency/polarization) and the various wheat growth parameters. The correlation between the different vegetation parameters and backscatter decreased with increasing frequency. L-band HH-polarization (L-HH) is best suited for the monitoring of fresh weight (r=0.98), dry weight (r=0.96), VWC (r=0.98), and plant height (r=0.96). The correlation coefficients were highest for L-band observations and lowest for X-band. Also, HH-polarization had the highest correlations among the polarization channels (HH, VV and HV). Based on the correlation analysis between backscattering coefficients in each band and wheat growth parameters, we developed prediction equations using the L-HH based on the observed relationships between L-HH and fresh weight, dry weight, VWC and plant height. The results of these analyses will be useful in determining the optimum microwave frequency and polarizations necessary for estimating vegetation parameters in the wheat.

• Korean Journal of Food Science and Technology
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• v.13 no.4
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• pp.314-318
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• 1981

In order to improve the storage stability of spray and freeze dried red ginseng extract powder packed in a bottle, the water vapor permeability of Al-foil laminate paper used for cap closure and shelf life of those products on various storage temperatures and relative humidities were investigated. The thickness of the laminate paper was $93{\pm}3\:{\mu}m$ and its physical properties were equal to standard of ASTM (B-377-66) The absorption rate of the freeze dried powder was 2-6 times greater than that of the spray dried powder at $37^{\circ}C$. Therefore it was considered that the laminate could be used for cap closures for the spray dried powder but unsuitable for the freeze dried powder. The shelf life of the spray dried powder was longer than that of the freeze-dried powder at $37^{\circ}C$.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.419-427
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• 2012

This study was carried out to investigate the effect of two shading methods, shading agent spray on the glasshouse and internal shading screen treatment, on the growth and fruit quality of paprika (Capsicum annuum L. 'Cupra' and 'Coletti') in summer season cultivation. In the shading agent treatment, a commercial shading agent diluted with water at a ratio of 1 : 4 was sprayed on the roof of a glasshouse. In the internal shading screen treatment, a 10~20% shaded screen was used during the day time when the sun radiation was greater than $700W{\cdot}m^{-2}$. Compared to the unshaded control, photosynthetic photon flux density (PPFD) decreased in the greenhouse in the shading agent (SA) and shading screen (SS) treatments by 20% and 30%, respectively. Lower air temperatures and higher relative humidities were observed in the SA than in both the control and the SS treatment. Time to reach the break point of humidity deficit $8g{\cdot}m^{-3}$ was 2 hours late in the SA than in both the control and the SS treatment. Compared to control, both the SA and the SS treatments showed lower instantaneous temperatures of leaf, fruit, and flower by $2^{\circ}C$, $5^{\circ}C$ and $3^{\circ}C$, respectively. There were no differences in number of branches, stem diameter, and leaf size among treatments although both shading treatments promoted plant height in both cultivars. Botrytis infection ratio declined with the SA treatment by 14.7% in 'Cupra' and 22.1% in 'Coletti' as compared to that in the control. Shading increased fruit size in both cultivars, whereas no differences were observed in the number of locules and thickness of fruit tissue among treatments. Shading treatment increased mean fruit weight by a range of 10 to 15 g per fruit, while it decreased soluble solids contents as compared to that in the control. Similar Hunter values were observed among treatments, while fruit firmness increased slightly in shading treatments. Compared to the control, shading treatments improved marketable fruits by 11.7~22.6% and increased the number of fruits per plant by 4~9.2 in both 'Cupra' and 'Coletti'. The results of this study indicate that shading agent application on the roof of glasshouse would be one of the most effective options to reduce heat stress imposed on the paprika crop in summer cultivation, resulting in improved crop growth and fruit yield.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.6 s.165
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• pp.955-965
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• 2007

Safety helmets are used widely in various industries by workers since they are legally required to wear them. However, thermal discomfort is one of the major complaints from helmet users. To relieve this problem, frozen gelled packs can be considered for use inside the helmets. In this paper, tests were performed on humans to evaluate the physiological strains of wearing safety helmets and to investigate the effects of using frozen gelled packs inside the helmets. Experiments were conducted in a climatic chamber of WBGT $33{\pm}1^{\circ}C$ under four differed experimental conditions: 1) not wearing a safety helmet(NH); 2) wearing a safety helmet with frozen gelled pack A(HA); 3) wearing a safety helmet with frozen gelled pack B(HB); and 4) wearing only a safety helmet(OH). The results were as follows. First, when comparing NH with OH, physiological responses such as $\bar{T}_{sk},\;T_r$, HR and sweat rate were significantly higher in OH and subjective sensations were reported as less hot and more comfortable than NH(p<.05). Second, in regard to the frozen gelled packs inserted inside the safety helmets, some physiological responses in HA were different from those in HB, according to the two different types of packs. HA was hotter, more uncomfortable and less exhausted than HB. However, result from both HA and HB were lower than those from OH in terms of temperature and humidity inside safety helmet, sweat rate, $T_r$ increase, heat storage(p<.05). When wearing safety helmets with frozen gelled packs, it was shown that heat strain can be alleviated. These results are expected to help millions of workers who complain that wearing safety helmets is uncomfortable and messy.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.156-166
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• 2000

This study was carried out to provide the information on seasonal variations of water content under highway asphalt pavements which influence on the dynamic behaviour and durability of pavements, and to assess the correlation between water content and soil or meteorological factors. Total eight sites for water content measurement which included fives sites in Kyungbu, two sites in Honam, and one site in Youngdong Highway were selected considering the variations in geology, topology and meteorology factors over all the country. Water contents under asphalt pavements were measured up to 170 cm depth every two week for total 13 months of August 1992 through September 1993 using neutron moisture meter(CPN-503DR). The range of water content ($\theta$$_{w}$) at the upper soils of above 50 cm depth was 7~12% and was not quite different regardless of sites, except for Iseo site. However, soil water contents below 60 or 70 cm depth were significantly different between the measurement sites, that is, the lowest water content was 5% at Kyungsan site and the highest water content was 20% at Iseo site. For all the sites, seasonal variations in water content during the experimental period were little, their range was within only 1 to 4%. Seasonal variations of water content in original or cutting area, which were 4% more or less, were slightly larger than in bedding areas, which were below 2%. Water contents under asphalt pavements had statistically significant positive correlations with silt and clay content in soil, but there were little correlations between water content and meteorological factors such as precipitation, relative humidity, mean air temperature, and wind velocity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4291-4297
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• 2015

EEG has been used to measure the emotion of amenity and discomfort in the interior space. EEG is limited to the experiment, because it is a equipment of contact type. However, Vibraimage can measure the emotion with a web camera. Because Vibraimage is a equipment of non-contact type, it is more suitable for the interior space than EEG. Therefor, it tries to find a correlation variable between EEG and Vibraimage to measure the human emotions. In this study, it were analyzed correlation of EEG and vibraimage due to variation of loudness 60[dB], 90[dB] and rosemary, jasmine scents. Check the health status of subjects who were selected 3 male students, and the period of this experiment was about months. The condition of the environmental test room was in temperature 25[$^{\circ}C$], relative humidity 50[RH%], air current speed 0.02[m/s] and illuminance 1000[lux]. It were analyzed correlation of twenty-three index of EEG(absolute ${\theta}$, relative ${\theta}$, absolute $S{\alpha}$, relative $S{\alpha}$, absolute ${\alpha}$, relative ${\alpha}$, absolute ${\beta}$, relative ${\beta}$, absolute $\gamma$, relative $\gamma$, absolute $F{\alpha}$, relative $F{\alpha}$, absolute SMR, relative SMR, $SMR/{\theta}$, $SMR+M{\beta}/{\theta}$, absolute $H{\beta}$, relative $H{\beta}$, $H{\beta}/{\alpha}$, absolute $M{\beta}$, relative $M{\beta}$, SEF50, ASEF50) and ten index of Vibraimage(Aggression, Stress, Tension/Anxiety, Suspect, Balance, Charm, Energy, Self regulation, Inhibition, Neuroticism). As a result, I was found that relative ${\gamma}$ index of EEG and neuroticism index of Vibraimage have a high correlation as (${\pm}$).414 and (${\pm}$).424.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.5
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• pp.274-279
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• 2006

The exact estimation of crop evapotranspiration containing reference or potential evapotranspiration is necessary for decision of crop water requirements. This study was carried out for the evaluation and application of various meteorological elements used for the calculation of reference evapotranspiration (RET) by FAO Penman-Monteith (PM) model. Meteorological elements including temperature, net radiation, soil heat flux, albedo, relative humidity, wind speed measured by meteorological instruments are required for RET calculation by FAO PM model. The average of albedo measured for crop growing period was 0.20, ranging from 0.12 to 0.23, and was slightly lower than 0.23. Determinant coefficients by measured albedo and green grass albedo were 0.97, 0.95 and standard errors were 0.74, 0.80 respectively. Usefulness of deductive regression models was admitted. To assess an influence of soil heat flux (G) on FAO PM, RET with G=0 was compared with RETs using G at 5cm soil depth ($G_{5cm}$) and G at surface ($G_{0cm}$). As the results, RET estimated by G=0 was well agreed with RET calculated by measured G. Therefore, estimated net radiation, G=0 and albedo of green grass could be used for RET calculation by FAO PM.