• The Korean Journal of Ecology
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• v.8 no.2
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• pp.61-68
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• 1985

The modeling of interception and absorption of light was studied in plant canopies at Mt. Kwanak. Followering results were obtained. Light intensity passing through the stacked leaves is attenuated exponentially. This phenomenon seems to be more clearly applied to the plant canopies, if they have large cumulative leaf area and are matured densely. Light interception and absorption are influenced by leaf thickness, shape pigments, and leaf area, and they have great effect on the maturation of canopies. It was confirmed that the light penetrating through the stratified canopies is decreased exponentially in dual pattern. The cumulative leaf area of a definite space in a certain plant canopy is the same as the growth of leaf area of the canopy at that time. A hypothetical model for calculating the light absorption in plant canopies, was established on the bases of phenomena that incident light is captured at the maximum level and light inerception effect is minimized by leaves.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.279-285
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• 2019

To estimate daily canopy photosynthesis, accurate estimation of canopy light interception according to a daily solar position is needed. However, this process needs a lot of cost, time, manpower, and difficulty when measuring manually. Various modeling approaches have been applied so far, but it was difficult to accurately estimate light interception by conventional methods. The objective of this study is to estimate the spatial distributions of light interception and photosynthetic rate of paprika with time by using 3D-scanned plant models and optical simulation. Structural models of greenhouse paprika were constructed with a portable 3D scanner. To investigate the change in canopy light interception by surrounding plants, the 3D paprika models were arranged at $1{\times}1$ and $9{\times}9$ isotropic forms with a distance of 60 cm between plants. The light interception was obtained by optical simulation, and the photosynthetic rate was calculated by a rectangular hyperbola model. The spatial distributions of canopy light interception of the 3D paprika model showed different patterns with solar altitude at 9:00, 12:00, and 15:00. The total canopy light interception decreased with an increase of surrounding plants like an arrangement of $9{\times}9$, and the decreasing rate was lowest at 12:00. The canopy photosynthetic rate showed a similar tendency with the canopy light interception, but its decreasing rate was lower than that of the light interception due to the saturation of photosynthetic rate of upper leaves of the plants. In this study, by using the 3D-scanned plant model and optical simulation, it was possible to analyze the light interception and photosynthesis of plant canopy under various conditions, and it can be an effective way to estimate accurate light interception and photosynthesis of plants.

• Journal of the Korean housing association
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• v.12 no.4
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• pp.219-226
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• 2001

This treatise measures and estimate sound insulation performance of apartment house. Sound insulation performance measured to the floor and wall. Measurement object is apartment occupancy ago of 100㎡ scale built to higher story in Taegu city. Floor Slav's light impact sound level interception performance interacted by benevolent person who carrying out availability of finish material important. Floor Slav's heavy impact sound level interception performance amounted estimation by being good more or less then light impact sound level interception performance. Because sound insulation performance of partition between adjoined generation is gad seldom, privacy infringement becomes anticipation. There was discussion about these results, and presented various kinds future research task to prove sound insulation performance of apartment house.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.237-332
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• 2002

We constructed ceiling structure and floor structure for elevation of sound insulation performance of concrete slab of apartment house. And, we wished to measure heavy floor impact sound level and light floor impact sound level of these structure. As the result, light floor impact sound level interception performance of concrete slab was measured by thing that construction work of gypsum baud is important. Heavy floor impact sound level interception performance was measured by thing that it is effective that construct to thickness about 30 millimeters on concrete Slav. It was measured effectively that heavy floor impact sound level interception performance constructs rubber chip to thickness about 30 millimeters on concrete Slav.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2003.11a
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• pp.73-76
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• 2003

This paper is contents about method to measure interception performance of shock noise of floor slab of apartment house to be simple. In the case of interception performance of light floor impact sound level, according to measurement method, grade of sound insulation performance showed greatly differently. But, in the case of interception performance of heavy floor impact sound level, it was similar result in all measurement method. Therefore, use of simple method of measurement was examined by possible fact in case of interception performance of heavy floor impact sound level.

• Journal of Ginseng Research
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• v.34 no.4
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• pp.274-281
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• 2010

This experiment was conducted to examine ginseng lines resistant and susceptible to high-temperature injury and to investigate characteristics of the selected lines: leaf burning phenomenon, chlorophyll content, quantum yield, and maximum light interception rate. The leaf burning phenomenon incidence rates of the resistant lines Yunpoong, high-temperature injury resistance (HTIR)1, HTIR2, and HTIR3 were low: 5.8%, 3.6%, 4.0%, and 1.9%, respectively. Resistance of the susceptible lines Chunpoong, high-temperature injury susceptible (HTIS)1, and HTIS2 was high: 58.5%, 23.2%, and 21.7%, respectively. The chlorophyll content (SPAD value) of the resistant lines Yunpoong, HTIR1, HTIR2, and HTIR3, which were exposed to high temperatures and intense light, remained as high at 24.8, 27.9, 24.9, and 30.6, respectively, but that of the susceptible lines Chunpoong, HTIS1, and HTIS2 was low at 21.0, 21.1, and 20.1, respectively. During the summer season, the quantum yield of the resistant lines (Yunpoong, HTIR1, HTIR2, and HTIR3) changed little, but that of the susceptible lines (Chunpoong, HTIS1, and HTIS2) changed dramatically. The maximum light interception rate (Fm/Fv value) for the resistant lines (Yunpoong, HTIR1, HTIR2, and HTIR3) was as high as 0.848, 0.794, 0.805, and 0.813, respectively, while that of the susceptible lines (Chunpoong, HTIS1, and HTIS2) was 0.678, 0.642, and 0.717, respectively. Based on these results, the high-temperature injury-resistant lines seemed to be less susceptible to high light, even at high temperatures. Future studies on red ginseng quality and its active ingredients in resistant ginseng lines and field experimentation will be conducted to verify the potential of the resistant lines.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.265-274
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• 1995

Characteristics of vegetative spur leaf, spur bud, fruiting supr leaf and flowering in relation to canopy position was investigated on order to promote better spur bud and flower bud differentiation on Citrus junos. There was no difference in vegetative spur leaf characteristics among directions. Vegetative spur leaf number and leaf area showed no difference between top and bottom position. There was no difference in spur bud size among directions, but spur bud at top was larger than that at bottom. Specific leaf weight of vegetative spur was mostly influenced by light interception, and leaf dry weight per spur average leaf dry weight, spur bud length and diameter had also a very high correlation with light interception rate. Shading and GA treatment in spur bud and flower bud differentiation was ineffective than natural light. Fruit thinning enhanced fruit quality as well as flower bud differentiation through an increase of leaf number per fruit, over 40 in Citrus junos.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.1
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• pp.13-19
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• 2020

This study compared RGB color images with canopy light interception (LI) and leaf area index (LAI) measurements for low cost and low labor. LAI and LI were measured from vertical gap fraction derived from top of digital image in soybean canopy cover (cv Daewonkong, Deapongkong and Pungsannamulkong). RGB color images, LAI, and LI were collected from V4.5 stage to R5stage. Image segmentation was based on excess green minus excess red index (ExG-ExR). There was a linear relationship between LAI measured with LI (r²=0.84). There was alinear relation ship between LI measured with canopy cover on image (CCI) (r²=0.94). There was a significant positive relationship(r²=0.74) between LAI and CCI at all grow ingseason. Therefore, it is expected that in the future, the RGB color image could be able to easily measure the LAI and the LI at low cost and low labor.

• Journal of the Korean GEO-environmental Society
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• v.1 no.1
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• pp.43-50
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• 2000

This paper presents the engineering property of light weight soil made of soil mixed with recycled stylofoam and stabilizer. Recycled stylofoam beads is able to use by lightweight fill materials because it is light, adiabatic, and effective for vibration interception. Especially, recycled stylofoam beads is easy to supply because stylofoam have been recycle item in 1996. In this study, physical and geotechnical properties of the light weight mixed soil(weathered granite soil mixed with Stylofoam Beads) were analyzed by laboratory experiments to examine its suitability for backfill materials. Laboratory tests were performed to evaluated strength, bearing capacity, weight, permeability, microphotograph analysis with variation of mixing ratio. Based on the results, it is concluded that the use of recycled stylofoam beads is acceptable lightweight fill.

• Journal of Ginseng Research
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• v.7 no.2
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• pp.172-192
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• 1983

Light environment and growth of Panax ginseng In habitat and cultivation under natural shade were renewed. Grower's experiences on ginseng stand In relation to light environment were assessed. Change of shading method and grower's concepts on light requirement of ginseng plant in Korea, Manchuria and Japan was counted. Growth of wild ginseng was better under rich light. Optimum crown density index appeared to be 0.7 In natural habitat and 0.4 to 0.7 for the cultivation in forest. Change of light Intensity in forest was greatest in May and reached near to constant value (from 40% to 3% for broad leaf deciduous forest and loom 4% to 2% for pine forest). Insufficient light condition induced long and thin stem, poor flowering and seed bearing, and sequent dormancy. Relation between light and ginseng strand was not clear but light Interception with cool weather was effective. Topography and orientation of bed have been deeply considered for light environment. Panel or bark of won were used for shading in deep forest manly In Manchuria while reed blind and straw thatch were used in Korea. Kinds and number of shades material and seasonal or daily schedule have been simplified probably by labor pressure due to eulargement of plantation. Post height has been greater while width of roof, bed and ditch has changed lisle. Scientific survey in the past omitted important light control methods (complete light hardening etc) which has been practiced in specific areas. The concept and technique of light control in the past in Korea were delicate and intensive including the control of temperature and moisture. For the application of old concept in modem cultivation precise Investigation of the technique including the measurement of light, temperature and moisture is needed.