• Journal of Biosystems Engineering
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• v.30 no.1 s.108
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• pp.45-55
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• 2005

Knowledge of the relationship between crop yield and yield-limiting factors is essential for precision farming. However, developing this knowledge is not easy because these yield-limiting factors are interrelated and affect crop yield in different ways. In this study, data for grain yield and yield-limiting factors, including crop chlorophyll content, soil chemical properties, and topography were collected for a small (0.3 ha) rice paddy field in Korea and a large (36 ha) upland corn field in the USA, and relationships were investigated with path analysis. Using this approach, the effects of limiting factors on crop yield could be separated into direct effects and indirect effects acting through other factors. Path analysis provided more insight into these complex relationships than did simple correlation or multiple linear regression analysis. Results of correlation analysis for the rice paddy field showed that EC, Ca, and $SiO_2$ had significant (P<0.1) correlations with rice yield, while pH, Ca, Mg, Na, $SiO_2,\;and\;P_2O_5$ had significant correlations with the SPAD chlorophyll reading. Path analysis provided additional information about the importance and contribution paths of soil variables to rice yield and growth. Ca had the highest direct effect (0.52) and indirect effect via Mg (-0.37) on rice yield. The indirect effect of Mg through Ca (0.51) was higher than the direct effect (-0.38). Path analysis also enabled more appropriate selection of important factors limiting crop yield by considering cause-and-effect relationships among predictor and response variables. For example, although pH showed a positive correlation (r=0.35) with SPAD readings, the correlation was mainly due to the indirect positive effects acting through Mg and $SiO_2$, while pH not only showed negative direct effects, but also negatively impacted indirect effects of other variables on SPAD readings. For the large upland Missouri corn field, two topographic factors, elevation and slope, had significant (P<0.1) direct effects on yield and highly significant (P<0.01) correlations with other limiting factors. Based on the correlation analysis alone, P and K were determined to be nutrients that would increase corn yield for this field. With the help of path analysis, however, increases in Mg could also be expected to increase corn yield in this case. In general, path analysis results were consistent with published optimum ranges of nutrients for rice and com production. We conclude that path analysis can be a useful tool to investigate interrelationships between crop yield and yield limiting factors on a site-specific basis.

• Journal of Life Science
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• v.22 no.4
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• pp.437-446
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• 2012

A metagenomic library of cow rumen in the pCC1FOS phage vector was screened in $E.$ $coli$ EPI300 for cellulase activity on carboxymethyl cellulose agar plates. One clone was partially digested with $Sau$3AI, ligated into the $Bam$HI site of the pBluescript II SK+ vector, and transformed into $E.$ $coli$ $DH5{\alpha}$. We obtained a 1.5 kb insert DNA, designated $cel$5C, which hydrolyzes carboxymethyl cellulose. The cel5C gene has an open reading frame (ORF) of 1,125 bp encoding 374 amino acids. It belongs to the glycosyl hydrolase family 5 with the conserved domain LIMEGFNEIN. The molecular mass of the Cel5C protein induced from $E.$ $coli$ $DH5{\alpha}$, as analyzed by CMC SDS-PAGE, appeared to be approximately 42 kDa. The enzyme showed optimum cellulase activity at pH 4.0, and $50^{\circ}C$. We examined whether the $cel$5C gene comes from the 49 identified cow rumen bacteria using PCR. No PCR bands were identified, suggesting that the $cel$5C gene came from the unidentified cow rumen bacteria.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5628-5636
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• 2012

Effective drying method of sewage sludge is researched in this study. To dry the sludge, chain crusher flash dryer was adopted to remove moisture content in the cell which is mostly responsible for the sludge moisture content. And Pilot plant experiment was conducted in real life sewage treatment plant to study effect and characteristics of operating conditions. Operating variables include sludge feeding rate, rotational speed of chain, process temperature and feed moisture content. As rotational speed of chain increased, product yield of sludge increased, and the performance of the testing system increased. And, as process temperature increased, the sludge drying efficiency increased. It is found that optimum feed moisture content is at 60% which shows the maximum sludge product yield and about 10 moisture content(%) of sludge product. Sludge feed rate showed optimal value, and when the sludge feed rate is exceeded, sludge product yield did not increased but the amount of residue increased. Pilot plant experiment results are as follow. The optimal condition for the rotational speed of chain 1600rpm(max. speed), final sludge discharge temperature $80^{\circ}C$, feed moisture content 60%, and feed rate 60kg/h. When the plant was operated at the optimal conditions, the final product showed fairly good results such as sludge product yield 85.5%, moisture content 11.0% and sludge drying efficiency 81.7%.

• Journal of Life Science
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• v.28 no.2
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• pp.195-200
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• 2018

Beta-asarone is the well-known active ingredient of Rhizoma acori graminei. In this study, we investigated and compared the binding affinity of mosquito oviposition pheromone (MOP; (5R,6S)-6-acetoxy-5-hexadecanolide) and beta-asarone on the A domain of the mosquito odorant binding protein 1 (CquiOBP1) by in silico computational docking studies. The three-dimensional crystallographic structure of CquiOBP1 was obtained from the PDB database (PDB ID: 3OGN). In silico computational auto-docking analysis was performed using PyRx, Autodock Vina, Discovery Studio Version 4.5, and the NX-QuickPharm option based on scoring functions. The beta-asarone showed optimum binding affinity (docking energy) with CquiOBP1 as -6.40 kcal/mol as compared to the MOP (-6.00 kcal/mol). Among the interacting amino acids (LEU76, LEU80, ALA88, MET89, HIS111, TRP114, and TYR122), tryptophan 114 in the CquiOBP1 active site significantly interacted with both MOP and beta-asarone. Amino acids substitution (mutation) from non-polar groups to the polar (or charged) groups of the CquiOBP1 dramatically changed the X, Y, Z grid position and binding affinity of both ligands. These results significantly indicated that beta-asarone could be a more potent ligand to the CquiOBP1 than MOP. Therefore, the extract of Rhizoma acori graminei or beta-asarone can be applied to the fields of insecticidal and repellant biomaterial development.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.4
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• pp.316-328
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• 2015

Purpose: The objects of this study was to evaluate the accuracy of the dental stone casts made from alginate impressions according to storage condition and stone pouring time. Materials and Methods: Each of upper and lower impressions of dental model was taken. The dental stone models were made immediately, 10, 30, 60, 180, 360 minutes after the impressions were taken at each storage condition. 3D models were constructed by scanning the stone model using 3D laser scanner. With Reference points, positioned on digital models, linear measurements of the dimensional change were compared by 3D metrology software, 3D average models were made and superimposition to identify the specific site of dimensional change and to measure surface deviation (mm). Results: Dental stone models which were made immediately after taking the impression showed the smallest linear dimensional change. As the stone pouring time was prolonged, the linear dimensional change was increased. More than 180 minutes after impression taking, linear dimensional change and surface distortion increased in the posterior molar region, regardless of the storage condition. Conclusion: For the optimum accuracy of the dental stone casts, alginate impression should be poured as soon as possible. If there were a need for storing, a humidor with 100% relative humidity must be used and be stored less than 180 minutes to fabricate the accurate dental model.

• Research in Plant Disease
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• v.8 no.3
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• pp.179-183
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• 2002

to investigate occurrence of kiwifruit bacterial canker disease,172 kiwifmit orchards in Jeonnam and Gyeong-nam provinces were surveyed from March to April in 1999. In the south coast region of Korea, such as Haenam, Wando, Jindo, Jangheung, and Bosuns, red-rusty brown bacterial oozes were observed in 17 kiwifvuit orchards. Disease incidences varied from 2.2% to 100% depending on various regions. Total 22.8 ha of kiwifruit orchards were destroyed by occurrence backerial canker at 1999 in Korea. Orchard in Wando, Jindo, and Goheng were severely damaged in 1999. The seasonal variation of bacterial canker incidence was also investigated from 1996 to 1997 on leaves, vines and twigs of kiwifruit. Red-rusty brown bacterial ooze was exuded from mid February or early March to late April in creaked site of vine and twig. The seasonal incidence of bacterial canker on leaves appeared from late April to late June, and rapidly increased during May, Optimum growth temperature of Pseudomonas sytingae pv. actinidiae was at $25^{\circ}C$ on King's B medium and did not grow at 33$^{\circ}C$. We suggest that spreading of bacterial canker was suppressed under the plastic flim and windbreak net house.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.1
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• pp.11-20
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• 2011

This study aimed to devise the method to construct safe and convenient bicycle road by considering the peripheral environmental factor related to using bicycle. Analyzing the existing design of bicycle road and construction case, this study established the method to design bicycle road that reflects site condition and presented the optimal design method for each type of bicycle road to construct safe and convenient bicycle road by analyzing the type of traffic accident for each type of bicycle road, surveying present situation and local survey. It was found that the optimum design of bicycle road for specification, width, curve radius, ascending slope, etc in consideration of peripheral environment and separating traffic between users of traffic means should be done by installing safety sign, safe facilities and separation facilities to design safe bicycle road. Further, the minimum traffic space of bicycle users and connection between bicycle roads should be ensured to design safe bicycle road. It is judged that information related to safety and convenience of bicycle road such as slope, route information, location of convenience facilities, information to the public traffic should be provided so as to activate the users of bicycle.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.4
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• pp.548-561
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• 2019

The surfgrass Phyllospadix japonicus is a dominant seagrass species playing critical ecological roles on the eastern coast of Korea. However, few studies have been conducted on the ecological characteristics of this species, generally due to the turbulent water conditions in its habitat. In this study, to examine the growth dynamics of P. japonicus, we investigated monthly changes in morphological characteristics, density, biomass, and leaf productivity as well as changes in the underwater irradiance, water temperature, and water column nutrient concentrations of its habitat from August 2017 to July 2018. Underwater irradiance and water temperature showed clear seasonal changes increasing in spring and summer and decreasing in fall and winter. Nutrient availability fluctuated substantially, but did not display any distinct seasonal trend. Morphological characteristics, shoot density, biomass, and leaf productivities of P. japonicus exhibited significant seasonal variations, increasing in spring and decreasing in fall months. Spadix of P. japonicus occurred from March to August, with the maximum spadix percentage(15.8%) occurred in May 2018. The average leaf productivity of P. japonicus per shoot and area were 2.1 mg sht^-1 d^-1 and 7.5 g m^-2 d^-1, respectively. The optimum water temperature for the growth of P. japonicus in this study was between 13-14℃. The productivity of P. japonicus was not correlated with underwater irradiance, water temperature and nutrient concentrations. These results suggest that the study site provide sufficient amount of underwater irradiance, suitable water temperature range and nutrients for the growth of P. japonicus.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.6
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• pp.579-586
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• 2010

Due to the recent development of measuring technology and 3D programs, it has become possible to obtain various spatial data. This study utilizes the 2-dimensional data and 3-dimensional data extraction technology based on the existing empirical and statistical DB. The data obtained from geospatial data technology are integrated with civil engineering BIM to conduct the modeling of the topography of the target region and select the optimum location condition by using the cut and fill balance of the volume of earth. The target area is the land around Tamjin River, Jangheong-gun, Jeolla-do. The 3-dimensional topology linked with 3-dimensional mapping technology by using the orth-image and aerial LiDAR that uses aerial photo of the target area is visualized with Civil3D of AutoDesk. By using Civil3D program, the Thanks to the recent development of measuring technology and 3D programs, target area is analyzed through visualization and related data can be obtained for analysis. The method of using civil engineering BIM enables to obtain various and accurate information about the target area which is helpful for addressing the issues risen from the existing methodology. In this regard, it aims at searching for the alternatives and provides suggestions to utilize the information.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.4
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• pp.261-265
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• 2003

Cold air accumulation plays a critical role in formulating daily minimum temperature in complex terrain on radiative cooling nights, and spatial interpolation can be improved by accommodating this important topoclimatic variable. Little is known about the spatial scale for computing cold air accumulation which influences daily minimum temperature. Air temperature was measured at 10-minute intervals during September 2002- February 2003 at eight locations within a 1 by 1 km hilly orchard area. Minimum temperature data for suspected radiative cooling nights were collected, and the deviations from reference observations at a near-by KMA automated weather station were calculated. A digital elevation model with a 10m cell size was used to calculate the cold air accumulation at 8 locations. Zonal averages of the cold air accumulation were computed for each location by increasing the cell radius from 1 to 10. Temperature deviations were regressed to a common logarithm of the smoothed averages of cold air accumulation to derive a linear relationship between the local temperature deviation and the site topography. The highest coefficient of determination ($r^2$ = 0.78) was found at a cell radius of 5, which corresponds to an approximately 1 ha boundary surrounding the point of interest.