• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.307-316
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• 1994

To investigate the effect of light pretreatment on photosynthetic characteristics of leaf blade of rice, 2 varieties of japonica type and 2 varieties of tongil type were grown under 30% or 70% shading conditions from tillering stage to heading stage. Shading treatment of 70% at the heading stage produced low dry matter, and higher LAR and SLA compared with other combination of shading treatment and growing stage did. Photosynthetic activity was lower in order of 0%, 30% and 70% shading treatment under the low light intensity(5Klux) but significantly high in 30% shading treatment under the high light intensity (33Klux) at tillering stage. Photosynthetic activity under low(5Klux) and high(33Kluk) light intensity were higher in order of 70%, 30% and 0% shading treatment at heading stage. Respiration /photosynthesis ratio was lower in shading treatment than in control. CGR, RGR and NAR decreased in shading treatment. Shading treatment reduced the number of ripened grain per panicle and decreased the harvesting index.

• Proceedings of the Korean Society of Crop Science Conference
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• 1998.04a
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• pp.111-112
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• 1998

• Korean Journal of Medicinal Crop Science
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• v.21 no.5
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• pp.394-400
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• 2013

This study was carried out in order to examine the germination characteristics of Atractylodes japonica seeds, and it was to develop the more efficient pre-treatment and production system of the seeds. Experiment was performed by two ways-temperature control (10, 15, 20, $25^{\circ}C$) and shading treatment (full sunlight, 35, 50, 75, 95% of full sunlight). Seed pre-treatment before the each experiment was carried out by temperature (with low temperature and wetting treatment (LTW) for 0, 15, 30, 45 and 60 days) and shading treatment (with drying at room temperature (DRT), drying at low temperature (DLT) and water soaking (WS) for 48 hours). Seeds of A. japonica were germinated well under temperature control (overall 85.3~100%), especially high temperature. And, the seeds pre-treated with LTW for 45 days germinated with a 100% success rate. Under the surveying shading treatment, the highest germination rate was 95.8% with DRT and overall 63.2~95.8%. Germination rate under seeds with WS was 63.2~7.8%. As a result of surveying the whole experiment, A. japonica seeds don't need to pre-treat cause of high germination, but if it is performed with LTW for a certain period of time, it would be more productive.

• Journal of Korean Society of Forest Science
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• v.76 no.1
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• pp.1-10
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• 1987

This study was carried out to examine the influence of shading and root-cutting on the survival and growth of Pinus koraiensis seedlings. 1, The highest survival percentage of seedlings transplanted to transplanting bed appeared at the plot of 19% in shading. The 50% of the seedlings were survived if half of them were root-cutting. 2. Shoot elongation, root growth and diameter increment were the best at the plot of 100% in relative light intensity. However, those were the best at the plot with 1/4 root cutting. 3. The increase of needle fascicle number and the growth of needle surface area per seedling were the longest at the plot of 63% relative light intensity. Among root cutting treatments the 1/4 cutting plot showed the largest growth of needle areas.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.181-188
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• 2020

This study was conducted to identify the optimal conditions for seedling growth in Veronica rotunda var. subintegra (Nakai) T.Yamaz. which a endemic plant and can be development as ornamental plants. We sowed V. rotunda var. subintegra (Nakai) T.Yamaz. seeds, and exposed the seedling was different treatment conditions. We varied soil type and fertilizer concentration, shading ratio, additional fertilizer concentration, pretreatment light exposure and collection time of seeds. We found that seedling growth was good in horticultural substrate (with no additional fertilizer), but mixed soils supplemented with fertilizer inhibited growth, regardless of the fertilizer concentration. In the 55% shading treatment, seedling growth was greater than in the non-shading treatment. High concentration addition of fertilizer (Hyponex) promoted plant growth, in terms of both plant length and fresh weight. Exposure of seeds to a red light-source prior to germination had a greater effect on seedling growth than exposure to other light sources. Seedlings exhibited better growth when grown from seed collected in 2018, rather than 2017.

• Journal of Korean Society of Forest Science
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• v.77 no.1
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• pp.100-108
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• 1988

This research was performed to estimate the influence of relative light intensity, planting density, growth period on the growth of fresh and dry weight of the stem and branches, and root in the pretreatment transplanting bed. 1. The growth of fresh and dry weight of the stem and branches per seedling varied in the order of 63%>100%>37%>19% in relative light intensity, and increased with decrease of planting density, and grew highly during the period from May to June. The contribution rates to the growth of fresh and dry weight of the stem and branches were 49.4% and 39.6% in shading treatment, and 4.3% and 6.4% in planting density, and 34.2% in growth period respectively. Of the three factors, that is, shading, density and period, all of the interactions between two factors, and among the three factors in the growth of fresh and dry weight of stem and branches were significant. The growth of fresh and dry weight of root per seedling increased with light intensity and decreased with increase of density. The best growth of root, showed during the period from May to June in fresh weight, but during the period from July and August in dry weight of root. For the three factors, that is, shading, density and growth period, all the interactions between any two factors, and among the three factors in the growth of fresh and dry weight of root were significant.

• Journal of Korean Society of Forest Science
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• v.76 no.3
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• pp.218-229
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• 1987

This study was carried out to investigate all the parts' weight growth under the different light intensity and root-cutting. As results : ${\cdot}$ Fresh and dry weight of leaf, shoot, root and seedling treated under 63% R.L.I showed the largest growth. ${\cdot}$ The largest growth in fresh and dry weight of shoot arid seedling appeared at 1/4 root cutting plot. ${\cdot}$ The value of T/R ratio was increased in low light intensity and high root-cutting. ${\cdot}$ The simple nonlinear relationship between light intensity, root-cutting and T/R ratio was recognized, respectively.

• Journal of Korean Society of Forest Science
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• v.77 no.2
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• pp.193-198
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• 1988

This study was carried out to investigate the influence of shading pretreatment and planting density on the periodic needle leaves growth in fresh and dry weight. 1. The fresh and dry weight growth of needle leaves per seedlings increased with light intensity and decreased with increase of density. The best growth of needle leaves in fresh weight and dry weight appeared during the period from May to June. 2. The contribution rates to the growth of fresh and dry weight of needle leaves were 1.9% and 5.1% in light intensity, 3.6% and 3.2% in density and 83.7% and 75.6% in growth period, respectively. 3. For the three factors, shading, density and growth period, all the interactions between any two factors, and among the three factors in the fresh and dry weight growth of leaves per plant were significant.

• Journal of Electrical Engineering and information Science
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• v.2 no.5
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• pp.65-71
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• 1997

We present heterojunction solar cells with a structure of metal/a-Si:H(n-i-p)/poly-Si(n-p)/metal for the terrestrial applications. This cell consists fo two component cells: a top n-i-p junction a-Si:Hi cell with wide-bandgap 1.8eV and a bottom n-p junction poly-Si cell with narrow-bandgap 1.1eV. The efficiency influencing factors of the solar cell were investigated in terms of simulation an experiment. Three main topics of the investigated study were the bottom cell with n-p junction poly-Si, the top a-Si:H cell with n-i-p junction, and the interface layer effects of heterojunction cell. The efficiency of bottom cell was improved with a pretreatment temperature of 900$^{\circ}C$, surface polishing, emitter thickness of 0.43$\mu\textrm{m}$, top Yb metal, and grid finger shading of 7% coverage. The process optimized cell showed a conversion efficiency about 16%. Top cell was grown by suing a photo-CVD system which gave an ion damage free and good p/i-a-Si:H layer interface. The heterojunction interface effect was examined with three different surface states; a chemical passivation, thermal oxide passivation, and Yb metal. the oxide passivated cell exhibited the higher photocurrent generation and better spectral response.

• Journal of Korean Society on Water Environment
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• v.37 no.6
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• pp.449-457
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• 2021

Photosynthesis and respiration rate of microalgae are important factors during advanced wastewater treatment research using microalgae, There are several equipments and measurement methods for measuring photosynthesis and respiration, with different challenges that occur during pretreatment and stabilization of the analysis process. Therefore, in this study, for accurate Photosynthesis and Respiration (P&R) analyzer measurement, the analysis process was divided into pre-processing, DO stabilization, and analysis stages and each was optimized to enable accurate evaluation. For this purpose, the effect of DO saturation of the sample on P&R analysis, DO stabilization according to the degassing flow rate, and photoinhibition of the OD level on photosynthesis was investigated. Based on our study results, when DO was supersaturated, photosynthetic efficiency decreased due to photorespiration, making it inappropriate as a P&R sample. In addition, 0.5 L-N2/min level was the optimal nitrogen degassing flow rate for DO desaturation. The inhibition of photosynthetic efficiency by self-shading caused by the increase in OD was observed from OD 2.0, and it was found that P& R analysis is preferably performed on samples with OD less than 2.0. In addition, based on the above three optimization results, an optimized P&R Analyzer instruction for accurate P&R analysis was also presented.