• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.22-32
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• 1997

This experiment was conducted to obtain information for the cultivation of Korean valerian(Valeriana lauriei var. dasycarpa Hara) which will be useful for medicinal and aromatic resources. The effect of different temperature conditions, light intensities and soil water conditions on growth, yield and component of essential oil of V. fauriei were measured at the Dankook University, Cheonan, and a study on the shading treatment was at Umsung, Chungchongbukdo, and Jinbu, Kangwondo, in 1995. V. laudei was planted at five different temperature conditions, 10, 15, 20, 25 and 3$0^{\circ}C$, eight light intensity conditions, 1, 000, 2, 500, 5, 000, 20, 000, 30, 000, 40, 000, 50, 000 and 60, 000lux, six soil water contents, 30, 45, 55, 70, 80 and 90％ of the saturated soil, during growth stage. Shading treatment was three conditions, 0, 25 and 50％, during the daytime in field conditions. Photosynthesis had a highly significant relationship with temperature conditions in a quadratic regression model, from which the temperature for the plant growth was estimated to be 17.7$^{\circ}C$. A highly significant quadratic regression was noted between temperature and leaf width or root weight of V. fauriei. It was estimated from the regression equation that the optimum temperature for root growth was 20.3$^{\circ}C$. The content of essential oil and extract rate of root was the highest in the 15~2$0^{\circ}C$. Photosynthesis also was significantly affected by light intensity in a quadratic regression model, from which the optimum light intensity for the growth was estimated to be 40, 000lux. Root yield was more produced in Jinbu than that of in Umsung. The root yield was increased by the shading treatment in Umsung, whereas it was decreased by the shading treatment in Jinbu. The content of essential oil was not affected by the shading treatment of plants during the cultivation, while the compositions of components of essential oil were related to the growing locations. As soil water content was higher, the growth and content of root extract were increased. The optimum soil moisture for the growth of V. fauriei was 80~90％ of the saturated soil. In summary, the results indicated that the growth, yield and component of essential oil in V. fauriei were affected by environmental factors as well as soil moisture.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.63-72
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• 2016

A study was conducted to evaluate the effect of collected region(Bongpyeong in Gangwon, 690 m, Mt. Halla in Jeju, 1,085 m), pre-treatment (stratification, soaked in distilled water or $GA_3$) and shading (control, 50%, 80%) on seed emergence and seedlings growth of Ligularia fischeri. The result showed that seed emergence (%) of L. fischeri were 6.9~75.5% (Gangwon : 6.9~32.8%, Halla : 22.2~75.5%). Maximum seed emergence (%) of 32.8 (Gangwon) and 75.5 (Halla) were achieved for seeds were stratified, soaked in distilled water, and under non-shading for L. fischeri (Gangwon), whereas seeds were stratified, soaked in $GA_3$ 100 ppm, and under 80% shading for L. fischeri (Halla). In this study, the best seedling vigor index (SVI) of L. fischeri (Gangwon) and L. fischeri (Halla) were obtained when seeds were stratified, soaked in distilled water, and under 50% shading. The survival rate of potted seedlings for L. fischeri (Halla) were 100% of all shading conditions, but there were decreased by 77.8%, 61.1%, 55.6%, as an increasing shading rate (con, 50%, 80%) for L. fischeri (Gangwon). Therefore, good seedlings were obtained when seed (Mt. Halla) of L. fischeri were stratified, soaked in distilled water, and under 50% shading, and then seedlings were transferred in pot.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.294-299
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• 2000

In order to find out the effects of shading and nitrogen fertilization on the accumulation of $NO_3\;^-$ in leaves of lettuce, lettuce plants were cultivated in the pots under glasshouse condition with different rates of shading(0, 50%) and nitrogen fertilization(100, 180, 200, 300, $400\;kg{\cdot}ha^{-1}$). The pH value was lower in soil after experiment than before experiment, whereas, contents of EC and $NO_3-N$ were higher. As the amounts of nitrogen fertilization were increased, pHs were decreased, but EC and the contents of $NO_3-N$ were increased. At the nitrogen fertilizations of 100, 180, 200, 300 and $400\;kg{\cdot}ha^{-1}$, the germination rates of lettuce were decreased to 84, 78, 76, 72 and 74%, and survival rates were also decreased to 94, 94, 90, 60 and 46%, respectively. However, the fresh weight of lettuce was highest at $45\;g{\cdot}plant^{-1}$ in the recommended fertilizer $plot(180\;kg{\cdot}ha^{-1})$ with non-shading condition. The contents of $NO_3\;^-$ in the leaves of lettuce were increased 2.8-4.1 times under 50% shading conditions than that under non-shading condition. It kept increasing up to seven order of growth phase; however, it started to decrease after eight order phase. Nitrate reductase activity of lettuce in non-shading condition was higher than that in 50% shading condition.

• Journal of Bio-Environment Control
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• v.23 no.1
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• pp.31-38
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• 2014

Rooting agents and shading treatments were tested in two different experiments to determine their effects on the establishment success of hardwood cuttings of three highbush blueberry varieties 'Bluecrop', 'Duke' and 'Sunrise'. For the experiment with rooting agents, one-cm long bases of the cuttings were dipped into solutions of IBA or NAA for 5 s, both at 0, 500 and $1000mg{\cdot}L^{-1}$ in 50% ethanol, and were also treated with Rootone$^{(R)}$ powder. Determined 90 days after cutting, the percent rooting and root weight were increased by NAA at $500mg{\cdot}L^{-1}$ in 'Bluecrop' and 'Sunrise', while in 'Duke' IBA at $500mg{\cdot}L^{-1}$ was effective. These auxin treatments were found to work better than a commercial product Rootone$^{(R)}$. The rooting agent-induced increases in root development resulted in better shoot growth of the cuttings in all three varieties, as determined after 90 days of further growth in individual containers. In the experiment with shading treatments, different levels of the shading treatment (30 to 90%) were imposed over the cutting bed under no mist. In all three varieties, 30% shading increased the percent rooting and root and shoot growth, compared to no shading control. However, shading levels higher than 50% shading were found to be inhibitory for hardwood cuttings of highbush blueberries, especially under the environmental conditions with no mist system.

• Weed & Turfgrass Science
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• v.7 no.2
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• pp.111-119
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• 2018

This study was carried out to investigate the differences in germination and growth of Quamoclit coccinea Moench under various temperatures, seeding depths, and levels of shading and soil moisture for effective weed management. Seed dormancy of Q. coccinea Moench was over 1 year; best results were obtained when seeds were soaked in sulfuric acid for 15 minutes in order to break the dormancy. Germination rates of Q. coccinea Moench ranged from 69 to 73% at $25-35^{\circ}C$ and 26% at $15^{\circ}C$. The germination rates ranged from 70-84% at 2, 3, 5, 7, and 8 cm of seeding depths. In addition, the germination rates were 7% and 13% at 12 cm and 15 cm of seeding depths, respectively, and showed normal growth at the both seeding depths. Q. coccinea Moench showed a high germination rate regardless of shading levels, but shoot fresh weight varied depending on the level of shading as follows: 20%>no shading=shading 35%>shading 50%>shading 75%=shading 90%. Q. coccinea Moench did not germinate when soil had a saturation rate of either 30% or 100%. However, 60-83% of seeds germinated with optimal growth when soil had saturation rates of 60% and 80%.

• Journal of the Korean Solar Energy Society
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• v.40 no.2
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• pp.25-36
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• 2020

The Korean government has a plan to mandate zero-energy buildings in 2020 for public and 2025 for private buildings. In order to design a zero-energy building, insulation and airtightness, which are the most basic elements of passive house technology, are required, and the government has been accomplished this through step-by-step strengthening of related standards. In passive house with high thermal insulation and airtightness performance, the heat introduced into the building through solar radiation can be stored for a long time to keep the inside warm during winter. On the other hand, during summer, heat introduced into the building cannot be easily released to outside, so it is necessary to actively block solar radiation and high temperature outdoor air to prevent an increase of indoor temperature. Therefore, this study aims to derive an appropriate operation condition of passive house to maintain the indoor temperature at an suitable level according to the ventilation methods and solar shading conditions. As a result, under the conditions that the outdoor temperature was 28℃ or less, the ventilation using a heat recovery ventilation system at daytime and natural ventilation at nighttime were selected for the most appropriate operation method. In addition, in the case of solar shading, it was found that blocking solar radiation at daytime using the blind and open the blind at nighttime to ensure natural ventilation were selected for the most appropriate solar shading condition.

• Korean Journal of Medicinal Crop Science
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• v.20 no.5
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• pp.320-330
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• 2012

This study was conducted to investigate the changes of chlorophyll contents, chlorophyll fluorescence, photosynthetic parameters, and leaf growth of Synurus deltoides under different shading treatments. S. deltoides was grown under non-treated (full sunlight) and three different shading conditions (Shaded 88~93%, 65~75%, and 45%~55%). Light compensation point ($L_{comp}$), dark respiration ($D_{resp}$), maximum photosynthesis rate ($Pn_{max}$), photo respiration rate ($P_{resp}$), carboxylation efficiency ($\Phi_{carb}$), and photochemical efficiency were decreased with increasing shading level; However, $CO_2$ compensation point ($CO_{2\;comp}$), total chlorophyll content, and specific leaf area (SLA) were shown the opposite trend. S. deltoides under 88~93% treatment showed the lowest photosynthetic activity such as maximum photosynthetic rate ($Pn_{max}$), photochemical efficiency, and $CO_2$ compensation point ($CO_{2\;comp}$). Therefore, photosynthetic activity will be sharply decreased with a long period of 8~12% of full sunlight. With the shading level decreased, carotenoid content and non-photochemical fluorescence quenching (NPQ) increased to prevent excessive light damage. This result suggested that growth and physiology of S. deltoides adapted to high light intensity through regulating its internal mechanism.

• Journal of the Korean Solar Energy Society
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• v.34 no.6
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• pp.75-83
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• 2014

Heat loss through windows and doors occupies 20 to 45% of the total heat loss in building. It accounts for a large proportion of the total heat loss in building. In order to suppress the amount of heat flow through the windows and doors were considered actions such as reinforcement of insulation performance of window, adoption of low-e glass, and installation of solar heat shading device. The Purpose of this study is to compare solar heat shading performances of 3 types of internal blinds in the summer. In order to verify the solar heat shading performances of the blinds, a roll blind, blind A(Venetian blind) and blind B(Daylight guiding venetian blind)were installed in the four rooms with the same environmental conditions. As a result of the experiment, the blind B, blind A, roll blind showed an excellent performance in that order. Its because the blind B is made of aluminum materials coated with special paints on surface. It doesn't converted to long wave by short wave light. and it is reflected to short wave to outside.

• Journal of the Korean housing association
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• v.23 no.2
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• pp.107-114
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• 2012

Thermally Activated Building System(TABS) is a radiant heating and cooling system which uses structures as thermal storage by embedding pipes in a concrete slab. Using TABS as the cooling system in residential buildings can reduce energy consumption and peak loads. But the ratio of cooling loads handled by TABS is low in the residential buildings which are significantly influenced by outside condition because condensation and over-cooling may occur. However, recent interest on energy-saving buildings is increasing and new residential buildings are expected to be less influenced by outside with high-insulation and shading. In such residential buildings, the heating and cooling loads and the range of load changes reduce. So the ratio of loads handled by TABS can increase. Therefore, this research investigates the cooling performance and energy performance of TABS in the residential buildings with less influence from outside using the simulation.

• Journal of Power Electronics
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• v.18 no.6
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• pp.1805-1818
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• 2018

This paper proposes a novel hybrid maximum power point tracking (MPPT) algorithm combining a Whale Optimization Algorithm (WOA) and the conventional Perturb & Observation (P&O) to track/extract the highest amount of power from a solar photovoltaic (SPV) system working under partial shading conditions (PSCs). The proposed hybrid algorithm is based on a WOA which predicts the initial global peak (GP) and is followed by P&O in the final stage to achieve a quicker convergence to a GP. Thus, this hybrid algorithm overcomes the computational burden encountered in a standalone WOA, grey wolf optimization (GWO) and hybrid GWO reported in the literature. The conventional algorithm searches for the maximum power point (MPP) in the predicted region by the WOA. The proposed MPPT technique is modelled and simulated using MATLAB/Simulink for simulating an environment to check its effectiveness in accurately tracking the MPP during the GP region. This hybrid algorithm is compared with a standalone WOA, GWO and hybrid GWO. From the simulating results, it is shown that the proposed algorithm offers high tracking performance and that it increases the output power level of a SPV system under partial shading. The algorithm also verified experimentally on various PSCs.