• Korean Journal of Agricultural and Forest Meteorology
• /
• v.20 no.2
• /
• pp.228-232
• /
• 2018

Process-based crop models have been used to assess the impact of climate change on crop production. These models are implemented in procedural or object oriented computer programming languages including FORTRAN, C++, Delphi, Java, which have a stiff learning curve. The requirement for a high level of computer programming is one of barriers for efforts to develop and improve crop models based on biophysical process. In this study, we attempted to develop a Chinese cabbage model using Microsoft Excel with Visual Basic for Application (VBA), which would be easy enough for most agricultural scientists to develop a simple model for crop growth simulation. Results from Soil-Plant-Atmosphere-Research (SPAR) experiments under six temperature conditions were used to determine parameters of the Chinese cabbage model. During a plant growing season in SPAR chambers, numbers of leaves, leaf areas, growth rate of plants were measured six times. Leaf photosynthesis was also measured using LI-6400 Potable Photosynthesis System. Farquhar, von Caemmerer, and Berry (FvCB) model was used to simulate a leaf-level photosynthesis process. A sun/shade model was used to scale up to canopy-level photosynthesis. An Excel add-in, which is a small VBA program to assist crop modeling, was used to implement a Chinese cabbage model under the environment of Excel organizing all of equations into a single set of crop model. The model was able to simulate hourly changes in photosynthesis, growth rate, and other physiological variables using meteorological input data. Estimates and measurements of dry weight obtained from six SPAR chambers were linearly related ($R^2=0.985$). This result indicated that the Excel/VBA can be widely used for many crop scientists to develop crop models.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.1
• /
• pp.28-33
• /
• 1996

This experiment was carried out at National Crop Experiment Station in 1994 to obtain basic information of growth characters and yield of rice under various seeding methods in direct seeding on dry paddy. Hwaseongbyeo sown on April 27 by flat drill seeding, high ridged drill seeding and hill seeding under different seed conditions, soil convering after seeding and irrigation methods. Nitrogen applied 150kg /ha by 3 times split application at rate of 40:30:30％ (basal: 5th leaf stage:panicle initiation stage). Seedling stands were higher in flushed irrigation water after seeding than in irrigation at 3rd leaf stage, and it also was higher in high ridged drill seedings than in flat drill seedings. Days for seedling stand, heading date were shorten 6~10 days, 2~3 days by flushed irrigation water after seeding, respectively. Number of tiller was more in high ridged drill seedings than conventional seedling method(Flat drill seeding ＋ intact seed ＋ soil covering after seeding ＋ irrigation at 3rd leaf stage after seedling stand) at early growth stage, but the most tiller number was highest in developed seeding method(Flat drill seeding ＋ soaked seed ＋ non soil covering after seeding ＋ fulshed irrigation water after seeding) at heading stage among used seeding methods. Lodging index was slightly high in high ridged drill seeding and conventional seeding. Field lodging was degree 1 in high ridged drill seedings and developed seeding, Milled rice yield in developed seeding was increased 7％ compaired with conventional seeding(5.35t /ha).

• Research in Plant Disease
• /
• v.22 no.3
• /
• pp.208-212
• /
• 2016

During the nursery seedlings stage at Muan in 2013, moisture and temperature conditions were favorable for the occurrence of onion downy mildew. Several fungicides were evaluated for controlling onion downy mildew at the stage of seedling. The disease incidence of the untreated control was 51.1%, which was sufficient to evaluate the fungicide efficacy for the control of onion downy mildew. Incidence at the mancozeb treatment (MAN treatment) was 4.4% and it was the highest control value of 91.4%. Incidence at the various fungicides treatment (MIX treatment) consisted of amectotradin plus dimethomorph, floupicolide plus propamocarb HCl, or dimethomorph plus pyraclostrobin was 10.0%, and the control value of the MIX treatment was 80.4%. Among the tested fungicides, amectotradin plus dimethomorph (AME plus DIM treatment) was selected and treated. Incidence of AME plus DIM treatment was 12.2%. There was statistically significant difference among the three different treatments and the untreated control. These results suggest that the application of fungicides on onion nursery seedlings was effective to control the onion downy mildew.

• International Journal of Highway Engineering
• /
• v.10 no.4
• /
• pp.151-159
• /
• 2008

Performances of retroreflectivity vary place to place, according to traffic volumes and time lengths after striping, depending on pavement marking materials and colors. The present paper uses the nation wide data of retroreflectivity, which has been collected from freeways and then tries to develop the regression curve setting traffic volume and service life as independent variables and retroreflectivities as dependent variables. The DB system includes two year's measurement in $2005{\sim}2006$ over Korean freeway pavement marking at an interval of three months for the period. The mobile measurement system, a laserlux, was employed for the purpose. The DB has provided a lot of information about materials and performance of the specific pavement marking such as geometric features, traffic volumes, material characteristics and the installation date. This study provides the comparison of pavement marking performances under diversified conditions. Based on accumulated pavement marking performances, this study provides performance curves based on the diversified factors. The goal of the retroreflectivity modeling is to develop equations that can be used to estimate an average retroreflectivity of pavement markings as a function time since application and traffic volume. After representing the variation of retroreflectivities and estimating regression curves by linear, exponential, logarithmic and power function, the regression curve which had the highest coefficient of determination and the value similar to the last field measurement was regarded as the retroreflectivity decay model. As a result of verification, the decay model showed the signification within the 90% confidence level and especially showed the clear relation with field data according to increase of cumulative vehicle exposure. Accordingly, these models can be used to determine service lives, retroreflectivity degradation rates, and retroreflectivity of new markings.

• Korean Journal of Remote Sensing
• /
• v.32 no.5
• /
• pp.529-538
• /
• 2016

This study, multispectral and hyperspectral sensors were utilized to use radiometric cross validation for the purpose of radiometric quality evaluation of a 'KOMPSAT-3'. Images of EO-1 Hyperion and Landsat-8 OLI sensors taken in PICS site were used. 2 sections that have 2 different types of ground coverage respectively were selected as the site of cross validation based on aerial hyperspectral sensor and TOA Reflectance. As a result of comparison between the TOA reflectance figures of KOMPSAT-3, EO-1 Hyperion and CASI-1500, the difference was roughly 4%. It is considered that it satisfies the radiological quality standard when the difference of figure of reflectance in a comparison to the other satellites is found within 5%. The difference in Blue, Green, Red band was approximately 3% as a comparison result of TOA reflectance. However the figure was relatively low in NIR band in a comparison to Landsat-8. It is thought that the relatively low reflectance is because there is a difference of band passes in NIR band of 2 sensors and in a case of KOMPSAT-3 sensor, a section of 940nm, which shows the strong absorption through water vapor, is included in band pass resulting in comparatively low reflectance. To overcome these conditions, more detailed analysis with the application of rescale method as Spectral Bandwidth Adjustment Factor (SBAF) is required.

• Journal of Korean Society of Steel Construction
• /
• v.16 no.5 s.72
• /
• pp.609-619
• /
• 2004

An investigation was conducted on the activities around Europe in order to solve the problem of the thermal bridging of steel studs, which had caused a significant disadvantage. This study included the following: diminishing the contact area between the studs and the sheathing, lengthening the heat transfer route, replacing the steel web with a less conductive material, and placing foam insulation in locations where the thermal shorts are most critical. Although energy efficiency is usually the focus of such foreign cases because their stud application is mostly limited to low-rise residential buildings, both structural and thermal performance are taken into consideration in this study because these target middle-story buildings. A hybrid stud composed of steel and polymer was also developed. This hybrid stud, which is 150 SL in size, is made of a galvanized steel sheet (SGC58) and a glass fiber reinforced polymer (GFRP) withepoxy bonding. A total of 32 specimens were manufactured. Its parameters comprise two types of connection detail,s: the thickness of steel (1.0mm and 1.2mm) and of the GFRP (4mm-4ply and 6mm-6ply), and the ratio of the length to the depth (L/D = 3, 6, 9, 12). Steel stud specimens with the same conditions were compared to the hybrid stud. The test revealed that in the case of the steel specimen with a thickness of 1.0mm, the maximum load of hybrid studs increased an average of 1.62 times comparedto that of the steel stud. In the case of the steel specimen with a thickness of 1.2mm, on the other hand, the average increase was 1.46times. All specimens showed full composite action until the collapse.

• Korean Journal of Soil Science and Fertilizer
• /
• v.7 no.3
• /
• pp.137-140
• /
• 1974

The present-state survey was carried out on reclaimed land of entire country to grasp the farming conditions, soil characteristics and productivities. The results was summarized as follows: 1) Among farmers participating in reclamation, small farmers, which hold land under cultivation less than 1 ha occupied 42 percent of total farmers; while big farmers, hold more than 3 ha, occupied only 11.1 percent. 2) The land use of reclaimed land by reclaimed year had such big variation that mulberry land was decreasing, however, grass land markedly increased. 3) Soils less than 15 percent slope in reclaimed land occupied 68.7 percent of total reclaimed land, and steep sloping land was reclaimed through bench-terraced method, while gently sloping land, through non terraced one. 4) The chemical properties of reclaimed land was very poor, except for phosphate, all element after 10 years of reclamation was under levels of land of cultivation. 5) Amount of fertilizer application to reclaimed land was under that of recommendation. 6) The yield of reclaimed land was 30 to 86 percent of average of land under cultivation.

• Korean Journal of Soil Science and Fertilizer
• /
• v.19 no.1
• /
• pp.76-82
• /
• 1986

A laboratory experiment was conducted to find out the denitrification rate upon the levels of nitrogen and source of organic matter in submerged sandy and sandy loam soil. The results obtained were sumarized as follows; 1. Evolution of nitrous oxide was increased at 1st and 10 days after incubation. And dinitrogen was increased at 1st and 30 days after incubation. Applications of green manure was enhanced the evolution of nitrous oxide ($N_2O$) and dinitrogen ($N_2$). 2. The cumulative denitrification rates at 50 days was high in Gyuam sandy loam soil (O-M: 1.52%) than that of Hamchang sandy soil (O-M: 3.81%). On the other hand, the cumulative emission of dinitrogen was high in Gyuam sandy loam soil while nitrous oxide was high in Hamchang sandy soil. The total mount of denitrification rate was high in order of green manure > rice straw > compost > control soil. 3. Increases of fertilizer nitrogen was enhanced the rate of emission of dinitrogen and nitrous oxide during the incubation time. 4. According to Michaelis-Menten kinetic equation, denitrification rates and reaction efficiency were remarkably increased by application of readily decomposable organic matter with in higher organic matter content of soil. 5. The negative relationship was observed between the evolution of dinitrogen and carbon ($CO_2+CH_4$) while the nitrous oxide with carbon was positive. 6. Under the this experiment conditions 1 mg of carbon was required for production of 4 mg N as $N_2O$ and 3 mg of N as $N_2$, respectively.

• Korean Journal of Weed Science
• /
• v.15 no.4
• /
• pp.262-269
• /
• 1995

The reseach was conducted to find out if there are any difference in growth, specific pattern in weed competition, and herbicide response of Korean lawngrass(Zoysia japonica Steud.) in a green house equipped with auto-foggy system. Plant height and leaf stage of Korean lowngrass under foggy condition were increased through all growing stages, whereas the number of tillers and shoot fresh weight harvested at 100 days after seeding were reduced by 24% and 29%, respectively, comparing with non-foggy condition. Weed emergence(total fresh weight) under foggy condition was much greater than that under non-foggy condition. Plant height, number of tillers, number of plant and shoot fresh weight of lawngrass under foggy condition were severely reduced with increasing the duration of competition(above 40 day-competition). Among the herbicides treated, oxyfluorfen completely inhibited plant height of lawngrass regardless of foggy condition, and bensulide considerably inhibited plant height of lawngrass under foggy condition. On the other hand, flazasulfuron did not affect the growth of lawngrass under both foggy and non-foggy conditions. At 40 days after herbicides application, weeding efficacy of bensulide and mecoprop under foggy condition were reduced by 6% and 13%, respectively, comparing with non-foggy condition.

• Nuclear Medicine and Molecular Imaging
• /
• v.43 no.4
• /
• pp.344-351
• /
• 2009

Purpose: Optical imaging is providing great advance and improvement in genetic and molecular imaging of animals and humans. Optical imaging system consists of optical imaging devices, which carry out major function for monitoring, tracing, and imaging in most of molecular in-vivo researches. In bio-luminescent imaging, small animals containing luciferase gene locally irradiate light, and emitted photons transmitted through skin of the small animals are imaged by using a high sensitive charged coupled device (CCD) camera. In this paper, we introduced optical imaging system for the image acquisition of bio-luminescent signals emitted from small animals. Materials and Methods: In the system, Nikon lens and four LED light sources were mounted at the inside of a dark box. A cooled CCD camera equipped with a control module was used. Results: We tested the performance of the optical imaging system using effendorf tube and light emitting bacteria which injected intravenously into CT26 tumor bearing nude mouse. The performance of implemented optical imaging system for bio-luminescence imaging was demonstrated and the feasibility of the system in small animal imaging application was proved. Conclusion: We anticipate this system could be a useful tool for the molecular imaging of small animals adaptable for various experimental conditions in future.