• Title, Summary, Keyword: shading effect

Search Result 318, Processing Time 0.043 seconds

The influence of outside temperature upon shading effect in greenhouses (외기온이 온실의 차광효과에 미치는 영향)

  • 이석건;이종원;이현우
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • /
    • pp.243-249
    • /
    • 1998
  • This study was conducted for analyzing the influence of outside temperature upon shading effect of greenhouses by simulation. The simulation program was tested by comparing predicted values to measured values and applied the Korean standard wide span glasshouse. The shading effect according to the variation of outside temperature was different by shading method and rate. The increasing rate of inside temperature with different shading rate was nearly propotional to the increasing value of outside temperature. The outside shading effect was a little better than inside shading.

  • PDF

Effect of Shading Types and Duration on Alleviation of High Temperature Stress in Cnidium officinale Makino (차광형태와 기간이 천궁의 고온피해 경감에 미치는 효과)

  • Nam, Hyo Hoon;Seo, Young Jin;Jang, Won Cheol
    • Korean Journal of Medicinal Crop Science
    • /
    • v.28 no.2
    • /
    • pp.111-118
    • /
    • 2020
  • Background: Cnidium officinale is a medicinal crop sensitive to high temperature. It is necessary to develop environment control technology that can reduce environmental stresses such as high temperature. This study was conducted to develop technology for stable production of Cnidium officinale by reducing damage owing to high temperature by applying shading treatment of varying duration, and structure. Methods and Results: Black shading nets were used from May to September or November; shading structures such as pillar, flat roof, and tunnel type structures were installed. Environmental changes, rate of photosynthesis, and growth characteristics were investigated. The shading treatment reduced temperature by 3℃. The rate of photosynthesis and yield with shading treatment were higher by 134% and 127%, respectively, than those with full sunlight. The ratio of shading area ranged from 50% to 71% according to the type of shading structure. The effect of environmental control on growth varied depending on the type of shading structure. Conclusions: The shading treatment reduced damage owing to high temperature, shading rate of 55% - 75% was recorded between the period May - September, and the flat roof type shading structure was considered the most suitable among shading methods.

Growth responses of sugar palm (Arenga pinnata (Wurmb.) Merr.) seedlings to different shading levels

  • Furqoni, Hafith;Junaedi, Ahmad;Wachjar, Ade;Yamamoto, Yoshinori
    • Proceedings of the Korean Society of Crop Science Conference
    • /
    • /
    • pp.49-49
    • /
    • 2017
  • Sugar palm (Arenga pinnata (Wurmb.) Merr.) grows naturally under shading of tree canopy, therefore shading levels take a main role for an optimal growth of sugar palm seedlings. The study was conducted to examine the effect of shading levels on the seedlings growth of sugar palm for up to 11 months under four shading levels: S0 (100% of full sunlight or non-shading), S1 (32% shading level), S2 (56% shading level), and S3 (64% shading level). Sugar palm seedlings grown under the shade (32, 56, and 64%) showed better plant height, stem diameter, leaf size, petiole and rachis length, chlorophyll content, root fresh and dry weights, root volume, and total biomass than those grown without shading. Although there were no significant different responses among the shading treatments on plant height, biomass dry weight, leaf morphological characters, chlorophyll content, and SPAD value, the S2 treatment showed a significant effect on a better root characters. Therefore, it can be concluded that the S2 treatment, 56% shading level, is an optimal shading condition for sugar palm seedlings.

  • PDF

VLSI Implementation of Adaptive Shading Correction System Supporting Multi-Resolution for Mobile Camera

  • Ha, Joo-Young;Lee, Sung-Mok;Jang, Won-Woo;Yang, Hoon-Gee;Kang, Bong-Soon
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.31 no.12C
    • /
    • pp.1201-1207
    • /
    • 2006
  • In this paper, we say the adaptive shading correction system supporting multi-resolution for mobile camera. The shading effect is caused by non-uniform illumination, non-uniform camera sensitivity, or even dirt and dust on glass (lens) surfaces. In general this shading effect is undesirable [1-3]. Eliminating it is frequently necessary for subsequent processing and especially when quantitative microscopy is the fine goal. The proposed system is available on thirty nine kinds of image resolutions scanned by interlaced and progressive type. Moreover, the system is using forty kinds of continuous quadratic equations instead of using the piece-wise linear curve which is composed of multiple line segments. Finally, the system could correct the shading effect without discontinuity in any image resolution. The proposed system is implemented in VLSI with cell library based on Hynix $0.25{\mu}m$ CMOS technology.

A Study on the Effect of Shading on a Photovoltaic Module

  • Baatarbileg, Ankhzaya;Otgongerel, Zulmandakh;Lee, Gae-Myoung
    • New Physics: Sae Mulli
    • /
    • v.68 no.11
    • /
    • pp.1215-1224
    • /
    • 2018
  • Most solar photovoltaic (PV) modules frequently get shadowed, completely or partially, resulting in a reduction of PV generation. This paper presents and compares the results from simulations and experimental measurements of the power output from a single PV module under various shading conditions. The study was carried out with a 90 W PV module and a 250 W PV module. The shaded area was increased from 0 to 100% for both variable and constant irradiances to analyze the effect of fluctuations in the solar irradiance certain shading conditions. The effect of shading for irradiance levels from 100 to $900W/m^2$ was investigated. Results showed that for every $100W/m^2$ decrease in the solar irradiance level, the power output decreased by 9, 0.7 and 1.5 W at 0, 25 and 50% shading, respectively. For solar irradiance levels higher than $500W/m^2$, the temperature increased by 1.6, 2.7 and $1.1^{\circ}C$ at 0, 25 and 50% shading, respectively, for every $100W/m^2$ increase in the irradiance.

An Experimental Study on the Effect on Indoor Environment by the Application of the Shading Device in Winter (동계에 차양 적용에 의한 실내 환경 측면의 효과에 관한 실험적 연구)

  • Paik, Joo-Young;Kim, Ji-Hyun;Yeo, Myoung-Souk;Kim, Kwang-Woo
    • Proceedings of the SAREK Conference
    • /
    • /
    • pp.854-859
    • /
    • 2006
  • This study aims to evaluate the effect on indoor environment by the application of the shading device on winter season. Therefore, thermal and visual experiments were conducted at two side-by-side mock-Lip test cells which were equipped with the shading device(venetian blind & roll blind) at interior and exterior side of the window. The results of this study are as follows: 1) At night of winter, the shading device can prevent internal heat from going out. 2) Exterior shading device is more effective in winter as well as in summer. 3) At daytime of winter, the shading device can provide the uniformity of illuminance, and the interior shading device is more effective.

  • PDF

Effect of Shading Degree and Rooting Media on Growth of Cuttings in Caragana sinica (Buc'hoz) Rehder and Sedum middendorffianum Maxim (차광 정도와 삽목용토가 골담초와 애기기린초의 삽수 생육에 미치는 영향)

  • Kim, Hyun Jin;Kim, Yoon Jin
    • Korean Journal of Medicinal Crop Science
    • /
    • v.23 no.4
    • /
    • pp.271-276
    • /
    • 2015
  • This study was conducted to investigate the effect of shading degree and rooting media on the growth of Caragana sinica and Sedum middendorffianum after cutting. In C. sinica, the highest rooting rate was obtained in cuttings planted in horticultural soil (Sunshine Mix #1) and peat moss mixture (peat moss : perlite = 1 : 1, v/v) under one layer of 35% shading and in cuttings planted in kanumatsuchi soil mixture (kanumatsuchi soil : decomposition of granite = 1 : 1, v/v) under non-shading. Whereas, regardless of shading degree, most cuttings of S. middendorffianum rooted in both horticultural soil and peat moss mixture. Cuttings of C. sinica showed the highest root length, 10.4cm in kanumatsuchi soil mixture under one layer of 35% shading but the highest fresh and dry weight of roots in kanumatsuchi soil mixture under non-shading. In S. middendorffianum, the highest root length, fresh and dry weight of root were obtained in cuttings planted in horticultural soil under non-shading. With these results, we recommended that cuttings of C. sinica should be propagated in kanumatsuchi soil mixture under non-shading and cuttings of S. middendorffianum in horticultural soil under non-shading.

Shading Effect of Different Colored Polyethylene net on Seeding Growth of Panax ginseng C. A. Meyer

  • Lee, Sung-Woo;Cha, Seon-Woo;Hyun, Dong-Yun;Kim, Young-Chang;Kang, Seung-Won;Seong, Nak-Sul
    • Korean Journal of Medicinal Crop Science
    • /
    • v.14 no.2
    • /
    • pp.113-116
    • /
    • 2006
  • This study was carried out to investigate spectral irradiance characteristics of blue, yellow, and blue-black colored polyethylene (PE) shading net and the effect on growth characteristics and yield in ginseng seedling. The spectral irradiance $({\mu}mol/m^2/s/nm)$ showed the peak at 498 nm in both of blue and blue-black PE shading net, and 606 nm under yellow PE one. The intensity of blue light in blue shading was more strong than that of blue-black shading, control. Blue shading was increased by 17% and 23% in accumulated quantum for daytime, $0.5^{\circ}C and $0.2^{\circ}C$ in maximum temperature on June 2 than that of yellow and blue-black shading, respectively, but heat injury ratio of the former was lower than that of the latter. Chlorophyll content and stem length in blue shading were decreased more significantly than those of yellow and blue-black shading. The specific leaf weight was higher under blue and yellow shading than that of blue-black shading. Ginseng seedling harvested in blue shading was increased by $13{\sim}17%$ in the number of root, and $17{\sim}20%$ in root weight per $m^ 2 compared to yellow and blue-black shading owing to the increase of survived plant, and the decrease of specific leaf weight, heat injury ratio, and stem length.

The Prediction of Interior Luminous Effect Through a Comparison of Shading Algorithms (음영처리기법의 비교를 통한 실내공간 조명효과의 예측)

  • Hong, Sung-De;Park, Hyoun-Jang
    • Journal of The Korean Digital Architecture Interior Association
    • /
    • v.5 no.1
    • /
    • pp.9-16
    • /
    • 2005
  • In Interior design, light is the most important factor in deciding color, texture and illumination level which are the basic factors of spatial design. To apply rendering technologies on prediction of illuminating effect, it is important to understand and analyse the basic properties of the illumination models that are local illumination model and global illumination model. The illumination models in computer graphics express the factors which determine the surface color, texture and light distribution through the reflection. The purpose of this study is to propose the best way of shading algorithm in interior space provided by the computer, based on the experimental analysis that 5 shading methods are applied to the interior space. The results of this study were as followed. 1) Local illumination models that are Lambert shading, Ground shading and Phong shading are not suitable to the prediction of interior illumination effect. 2) Ray tracing that is global illumination model could be adopted to interior illumination effects. Ray tracing is a very versatile algorithm because of the large range of lighting effects it can model. 3) Neither radiality nor ray tracing offers a complete solution for simulating all interior illumination effects. 4) Radiosity excels at rendering diffuse-to-diffuse inter-reflections and ray tracing excels at rendering specular reflections. By merging both shading techniques, that offers the best of both. Using computer technologies to simulate lighting in preliminary design stage which will provide information for designers and occupants to determine the effect of using artificial light sources at each stage of their design process. Further study in illumination analysis, prediction of illumination effect, and lighting calculation is required as computer media expands.

  • PDF

Effects of shading on the growth of variegated liriope (Liriope platyphylla Wang et Tang. forma variegata Hort) (차광이 반입맥문동(Liriope platyphylla Wang et Tang. forma variegata Hort.)의 생육에 미치는 영향)

  • 최상태;김지은;박인환;안형근;김성태
    • Asian Journal of Turfgrass Science
    • /
    • v.15 no.2
    • /
    • pp.77-86
    • /
    • 2001
  • The experiments were carried out to investigate effect of shading rare on variegata appearance and leaf growth of variegated liriope (Liriope platyphylla Wang et Tang variegata Hort.) The plant was grown under four different light intensities such as 0(natural light intensity), 25, 50 and 75% shading conditions. Leaf variegata appearance was better in the light than in the shade. Leaf showed good growth at 0, 25% shading treatment, average leaf width and area of yellow part were highest at 0% shading treatment. As increased shading rate, number of stomate per unit area decreased. Total chlorophyll of the whole leaf and green part were reduced by increasing shading rate, while yellow part showed oppositely. In the epidermis, cell size of 75% shading treatment showed larger than those of 0% shading treatment.

  • PDF