• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.292-298
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• 1997

To compare the growth pattern of ginseng plant under between conventional shading(light transmittance rate 3％) and polyethylene net shading(light transmittance rate 10％), the distribution of leaf area, specific leaf weight (S. L. W), leaf and stem dry weight and changes in light intensity were investigated in 2, 4 and 6 year old ginseng plant populations. Light transmittance rate(L.T.R.) was 3％ at front line, 2％ at middle line and 1.5％ at rear line under conventional shading but it was 12, 10 and 8％ under polyethylene net(P.E) shading, respectively. In 2 year old population, there was a little difference in the growth characteristics investigated between conventional and P.E. shading. In 4 year old field, the leaf area, stem and leaf dry weight decreased in large amount in the order of middle, and rear line on ridge under conventional shading, but with a little difference under P.E. shading. And these trends enlarged in 6 year old field with appearance of a large part of shoot over furrow from ridge planted ginseng. Root yield index was much lowered at the rear 3rd, 4th and 5th line of the conventional shading bed, but there was no yield difference among lines except 5th lines under the P.E. shading with higher yield by 28％ than conventional shading.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.212-217
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• 1981

The evaluate the effect of plant spacing on cured leaf of burley tobacco, the row spacings divided to 90, 105, 120cm and hill spacings to 30, 35, 40cm within each row. Growth amount per plant increased with thinner row and wider hill spacing in the same planting density. Relative light intensity increased with thinner row spacing in cutters and leaf and showed the positive correlation with quality. When the planting density was equal, the wider hill spacings, the more effective in utillization of solar radiation. The more plants per l0a were, the greater yield was obtained, and in the case of 3,200 plants per 10a (the most dense planting plot) was 267kg. But, quality, total-alkaloid and total-nitrogen content decreased with dense planting. Value per 10a was highest in the plots of 90 $\times$ 40cm and $105{\times}40cm$. In conclusion the optimum density level was 2,400 to 2,700 plants per 10a and spacing of tobacco either in 105 $\times$ 35 cm or 105 $\times$ 40cm seems to be most appropriate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.123-130
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• 1996

Experiments were conducted to effect of seeding rates and growth regulator (KIM-112) application on lodging resistance and yield in direct seeding on flooded paddy surface. The number of seedlings per $m^2$ were ranged from 61 to 143, and seedling ratios were from 71.7 to 76.1％. The culm length was increased with the higher seeding rates. The culm length was significantly shortened by KIM-112 application, and the shortened effect of internodes were various with application times. The leaf angles with the culm and top leaves were errected and position of light reception by KIM-112 application, also the weight of culm base was increased. The bending moment at breaking of culm and culm diameter were decreased according to the higher seeding rates. The number of panicles per $m^2$ were increased according to the higher seeding rates. The ripened grain rate and 1, 000 grains weight became higher than the untreated control.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.1042-1046
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• 1997

Fused deposition modelling(FDM) is a rapid prototyping(RP) process that fabricates part layer by layer by deposition of molten thennoplastic material extrude from a nozzle. RP system has many benefit. One of the benefit would be the ability to experiment with physical objects of any complexity in a relatively short period of time. But it has a matter of surface roughness and geometric accuracy. We research into a change of Surface roughness making the sphere by adjustment of extrusion in FDM.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.389-392
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• 2012

연기감지기는 이온전류의 변화량을 감지하는 이온화식 연기감지기와 발광부와 수광부로 이루어진 챔버내에 연기에 의한 광량의 변화를 감지하는 광전식 연기감지기로 구분된다. 국내에서는 광전식 연기감지기가 더 많이 사용되고 있는데 이러한 광전식 연기감지기의 챔버내에 이물질이 침입하게 되면 비화재보를 발생시키게 된다. 본 논문은 연기감지기의 연기감지 챔버에 대한 비화재보를 감소시키기 위한 신뢰성 시험에 대하여 논한 연구이다. 광전식 연기감지기의 신뢰성을 검증하는 방법으로는 먼지에 대한 신뢰성을 검증하는 가연물 종류에 따른 연기감지 신뢰성 시험이나 분진시험이 적합한 것으로 판단되며, 이러한 시험의 반복을 통하여 광전식 연기감지기의 신뢰성을 검증하는 것이 필요한 것으로 사료된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.178-178
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• 2018

차량용 강우센서는 강우에 따라 와이퍼의 동작 속도를 제어하기 위해 만들어졌다. 따라서 강수의 크고 적음을 대략적으로 판단하여 와이퍼의 속도단계를 결정하기 위한 장치이다. 차량용 강우 센서는 동작원리는 송수신되는 광신호에 기반한다. 일반적인 강우관측기와 달리 물 입자가 커질수록 빛의 산란이 크게 일어나는 현상을 이용한다. 산란이 크게 일어나면 강우 센서에 수광부의 광신호 값이 줄고 이는 강수가 높다는 것을 의미한다. 따라서 센서의 감지신호(Signal)와 실제강우(R)과의 관계를 이용하여 강우량으로 환산할 수 있는 R-S관계식을 개발하였다. 센서의 감지 신호(Signal)를 강우량으로 환산하기 위하여 실내 강우발생 실험 장치를 이용하여 일정 강우(R)를 증가시키고 그때 발생된 센서 감지량(S)의 관계를 수치적으로 분석하여 상관식을 만들었으며 실제 AWS, 자기우량계와 비교 분석하였다.

• Journal of Plant Biology
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• v.28 no.1
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• pp.1-8
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• 1985

To verify the cause of high productivity in Typha stand, leaf area index(LAI), leaf orientation and inclination, specific leaf area (SLA), and radiation interception profiles were determined in a natural Typha$\times$glauca stand. Throughout the growing season, the leaf inclination has been kept at near-right angle and leaf orientation has been random. These chracteristics were responsible for an uniform spatial arrangement of the leaves within the canopy and could be explained by the SLA value, which increased in their higher strata. The extinction coefficient (K) of the canopy, 0.12 to 0.20, was one of the smallest value out of terrestrial plant communities. At least more than 25% of full radiation penetrated into the lowest stratum of the canopy. High productivity of the Typha would be attributed to efficient penetration of the radiation in virtue of the stiff and straight leaves even though rather small LAI.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.1
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• pp.13-18
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• 2009

Accurate solar radiation data are critical to evaluate major physiological responses of plants. For most upland crops and orchard plants growing in complex terrain, however, it is not easy for farmers or agronomists to access solar irradiance data. Here we suggest a simple method using a sun-slope geometry based topographical coefficient to estimate daily solar irradiance on any sloping surfaces from global solar radiation measured at a nearby weather station. An hourly solar irradiance ratio ($W_i$) between sloping and horizontal surface is defined as multiplication of the relative solar intensity($k_i$) and the slope irradiance ratio($r_i$) at an hourly interval. The $k_i$ is the ratio of hourly solar radiation to the 24 hour cumulative radiation on a horizontal surface under clear sky conditions. The $r_i$ is the ratio of clear sky radiation on a given slope to that on a horizontal reference. Daily coefficient for slope correction is simply the sum of $W_i$ on each date. We calculated daily solar irradiance at 8 side slope locations circumventing a cone-shaped parasitic volcano(c.a., 570m diameter for the bottom circle and 90m bottom-to-top height) by multiplying these coefficients to the global solar radiation measured horizontally. Comparison with the measured slope irradiance from April 2007 to March 2008 resulted in the root mean square error(RMSE) of $1.61MJ\;m^{-2}$ for the whole period but the RMSE for April to October(i.e., major cropping season in Korea) was much lower and satisfied the 5% error tolerance for radiation measurement. The RMSE was smallest in October regardless of slope aspect, and the aspect dependent variation of RMSE was greatest in November. Annual variation in RMSE was greatest on north and south facing slopes, followed by southwest, southeast, and northwest slopes in decreasing order. Once the coefficients are prepared, global solar radiation data from nearby stations can be easily converted to the solar irradiance map at landscape scales with the operational reliability in cropping season.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.1
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• pp.25-31
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• 2008

Information on daily maximum air temperature is important in predicting the status of plants and insects, but the uneven and sparse distribution of weather stations prohibits timely access to the data in regions with complex topography. Since cumulative solar irradiance plays a critical role in determining daily maximum temperature on any sloping surfaces, derivation of a quantitative relationship between cumulative solar irradiance and the resultant daily maximum temperature is a prerequisite to development of such estimation models. Air temperatures at 8 sideslope locations with similar elevation and slope angle but aspect, circumventing a cone-shaped, grass-covered parasitic volcano (c.a., 570 m diameter for the bottom circle and 90m bottom-to-top height), were measured from June to December in 2007. Daily maximum temperatures from each location were compared with the average of 8 locations (assumed to be the temperature measured at a "horizontal reference" position). The temperature deviation at all locations increased with the day of year (or sun elevation) from summer solstice to winter solstice. Averaged over the entire period, the south facing location was warmer by $1^{\circ}C$ in daily maximum temperature than "horizontal reference" and the north facing location was cooler by $0.8^{\circ}C$ than the reference, resulting in the year round average south-north temperature difference of $1.8^{\circ}C$. In November, both south and north facing slopes showed the greatest deviation of $+2.0^{\circ}C$ and $-1.3^{\circ}C$, respectively in daily maximum temperature at monthly scale. On a daily scale, the greatest deviation was +3.8 and $2.7^{\circ}C$ at the south and north slope, respectively. The cumulative solar irradiance (on the slope for 4 hours from 11:00 to 15:00 TST) explained >60% of the variance in daily maximum temperature deviations among 8 locations, suggesting a feasibility of developing an estimation model for daily maximum temperature over complex topography at landscape scales.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.04a
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• pp.150-151
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• 2013

화재감지기는 연기감지기는 이온전류의 변화량을 감지하는 이온화식 연기감지기와 발광부와 수광부로 이루어진 챔버내에 연기에 의한 광량의 변화를 감지하는 광전식 연기감지기로 구분된다. 국내에서는 광전식 연기감지기가 더 많이 사용되고 있는데 이러한 광전식 연기감지기의 챔버내에 이물질이 침입하게 되면 비화재보를 발생시키게 된다. 본 논문은 연기감지기의 연기감지 챔버에 대한 비화재보를 감소시키기 위한 신뢰성 시험에 대하여 논한 연구이다. 본 연구에서는 광전식 연기감지기의 신뢰성을 검증하는 방법으로 UL 268 등에 규정되어 있는 먼지, 즉, 분진에 대한 신뢰성을 검증방법을 제시하였다. 먼지에 대한 신뢰성 검증을 보다 적절하게 하기 위하여 분진챔버로 분진을 반복적으로 폭로됨에 따른 감도성능 변화를 분석하는 방법이 필요할 것으로 사료된다.