• Korean Journal of Agricultural Science
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• v.28 no.1
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• pp.8-17
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• 2001

This study was carried out to obtain a basic intonation for the development of a new com hybird with tillers. Materials used in this study were 20 lines having three to four tillers per plant including the PI213749 U.S. line with non-tillers. These 20 lines were compared for the botanical characteristics and genetic distances were measured using RAPD analysis. Flowering date of the K15 was very earlier, while the K07 was very late in flowering date. Stem height and ear height were similar except for K04 and the K15. K06, K13 and K19 lines were appeared to be resistant to lodging due to decreased ear height. Number of tillers per plant of lines used were shown three to five on average. K09 showed the highest kernel yield, while the K08 was low. Among characteristics measured tiller per plant and flowering dates, and silking dates showed a positive correlation, while 100 kernels weight, flowering date and ear height were shown a negative with tillers per plant. A total of 17 bands by RAPD analysis using four per primer were appeared and these lines were classified into three groups, especially the third group could be classified into of four sub-groups.

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.667-672
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• 2011

This study was carried out to increase the breeding rate using sustained recombinant bovine somatotropin (bST) and examine the reproductive disorder and disease prevalencies of cow and calf, respectively. Sixty cows were allotted randomly to three groups in randomized complete block design; (1) No treatment, (2) 500 mg bST two times + 250 mg bST SC injection five times from 3 weeks before to 9 weeks after parturition every two weeks, (3) 500 mg bST two times before 3 weeks parturition + 250 mg bST SC injection three times from five to 9 weeks after parturition every two weeks. Developmental data of birth weight, weaning weight, total gain and average daily gain in control was $22.9{\mu}0.45$ kg, $88.0{\mu}1.13$ kg, $65.1{\mu}0.74$ kg and $0.54{\mu}0.08$ kg, respectively. There is no significant difference between Group 1 and 3 in the examined factors. However, there is significant difference between Group 1 and 2 in the birth weight ($24.4{\mu}0.88$ kg), weaning weight ($101.0{\mu}1.77$ kg), total gain ($76.7{\mu}0.9$ kg) and average daily gain ($76.7{\mu}0.9$ kg). Total gain was showed higher in Group 2 and 3 than Group 1 in the >2nd parity, and in Group 2 than Group 1 and 3 in the 1st parity. There is no significant difference in the BCS, no return days and disease occurrence of cow and calf by bST treatment. Number of service per conception was slightly increased in the Group 3 compared to Group 1 and 2. To increase the breeding ability of Hanwoo, it is recommended that 500 mg bST two times + 250 mg bST injection five times from 3 weeks before to 9 weeks after parturition every two weeks.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.3
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• pp.471-480
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• 2002

In this paper, the thermal stress analysis of spent nuclear fuel disposal canister in a deep repository at 500 m underground is carried out for the basic design of the canister. Since the nuclear fuel disposal usually emits much heat, a long term safe repository at a deep bedrock is used. Under this situation, the canister experiences the thermal load due to the heat generation of spent nuclear fuels in the basket. Hence, in this paper the thermal stress analysis is executed using the finite element method. The finite clement code Eot the analysis Is not written directly, but a commercial code, NISA, is used because of the complexity of the structure and the large number of elements required for the analysis. The analysis result shows that even though the thermal stress is added to the stress generated by the hydrostatic underground water pressure and the swelling pressure of the bentonite buffer, the total stress is still smaller than the yield stress of the cast iron. Hence, the canister is still structurally safe when the thermal loads we included in the external loads applied on the canister.

• Korean journal of applied entomology
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• v.47 no.2
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• pp.149-154
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• 2008

Pyrausta panopealis is the major pest in green perilla. The larva weaves a web on the shoot of green perilla and damages. In case of extreme, The larva cuts the main branch of green perilla and the leaf of green perilla isn't harvested anymore. A field study was conducted to estimate economic injury levels (EILs) and control thresholds (CTs) for P. panopealis injuring green perilla in green-houses. Different densities of P. panopealis ranged from 1 to 20 crops (2 units per crop) per 100 crops on 13. June, early inoculation. The number of injured leaf and the rate of injured crop were increased by 23. June, on the other hand were decreased after that day. Also, the amount of yield sow the same result above. The economic loss time calculated by the ratio of cost managing this moth to market price (C/V) (C: cost managing a moth, V: Market price) was 4.0%. The economic injury level was 5.1 larval per 100 crops. The control thresholds calculated by 80% level of economic injury level was 4.1 larval per 100 crops.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.253-257
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• 2011

This study was carried out to investigate the effect of different light emitting diode (LED) irradiation on the growth of paprika (Capsicum annuum 'Cupra'). The plants were irradiated by red (660 nm), blue (460 nm) and red + blue (4 : 1) light emitting diodes above 50 cm for 5 hours after sunset. Photosynthetic photon flux (PPF) irradiated by red, blue and red + blue LED were $79{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, $75{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and $102{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ respectively. Leaf temperature of paprika grown under blue LED irradiation was the highest of $18.6^{\circ}C$. Fruit temperature was the highest under in the control (no irradiation) but it was lower than leaf temperature. There was influence of LED irradiation on the paprika plants height; under blue irradiation the plant height was the shortest, while under in the control plant height was the highest. The leaf size of under different LED irradiation was bigger than that of in the control. Mean fruit weight under different LED irradiation was significantly increased; however number of fruits and marketable yield per plant were significantly decreased as compared to the control.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.40-46
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• 2017

Shipping activities have become possible in the Arctic Ocean due to melting ice by global warming. An increasing number of vessels are passing through the Arctic Ocean consequently bringing concerns of ship-iceberg collisions. Thus, most classification societies have implemented regulations to determine requirements for ice strengthening in ship structures. This paper presents the simulation results of an ice-strengthened polar class ship after an iceberg collision. The ice-strengthened polar class ship was created in accordance with the Unified Requirements for a Polar-Ship (IACS URI). An elastic-perfect plastic ice model was adopted for this simulation with a spherical shape. A Tsai-Wu yield surface was also used for the ice model. Collision simulations were conducted under the commercial code LS-DYNA 971. Hull deformations on the ice-strengthened foreship structure and collision interaction forces have been analysed in this paper. A normal-strength ship structure in an iceberg collision was also simulated to present comparison results. Distinct differences in structural strength against ice impact forces were shown between the ice-strengthened and normal-strength ship structures in the simulation results. About 1.8 m depth of hull deformation was found on the normal ship, whereas 1.0 m depth of hull deformation was left on the ice-strengthened polar class ship.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.26 no.2
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• pp.133-145
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• 1996

Aspirating or swallowing foreign bodies is a common occurrence. If they are wholly or partly radiopaque, their localization in and progress through the gastrointestinal tract can be more effective. Of the dental origin foreign materials swallowed, the most common things are fragments of anterior maxillary partial denture. But the radiopacity of denture base resins is not sufficient to determine the location of the objects. The purpose of this study was to develop a radiopaque dental acrylic resin, which has clinically detectible radiopacity with minimal change of mechanical properties and color. The radiopacity, color change(CIE 6..E) and microhardness of acrylic resins were determined after mixing barium sulfate or iodide compound. Thermocycling course was conducted to determine the change of characteristic of resins after using for a long time in the mouth. Five or ten percent of barium sulfate to total weight of cured material was mixed with heat curing dental acrylic resin or chemically curing orthodontic resin. In the case of iodide compound, the mixing ratio was two or three percent. After mixing the high radiopaque materials, resin was cured to 20×20×2 mm plate, polished with #600 sand paper and finally polished with Microcloth(Buehler). The specimens were thermocycled in 5 and 55 t distilled water for 2,000 times, and the measurement of radiopacity, color and Vickers hardness was repeated every 500 times thcrmocycling. The radiopacity of specimens on the X -ray films was measured with densitometer(X-rite). The color change was detennined with differential colorimeter(Model TC-6FX, Tokyo Denshoku), and the Vickers hardness number was measured with microhardness tester(Mitsuzawa). The following results were obtained : 1. All the three variables, the kinds of acrylic resins, the mixing or the kinds of high radiopaque materials and thermocycling, had combined effect on the radiopacity of the dental acrylic resins(p<0.0l). 2. The two variables, the mixing or the kinds of high radiopaque materials and thermocycling, influenced on the radiopacity of the dental acrylic resins(p<0.01). But the kinds of acrylic resins did not influence on the color change of mixed dental acrylic resins(p>0.05). 3. Each of the three variables, the kinds of acrylic resins, the mixing or the kinds of high radiopaque materials and thermocycling, influenced on the radiopacity of dental acrylic resins(p<0.0l). 4. The high radiopaque materials used in this study did not yield clinically usable radiopacity, and the color change was great after mixing those materials.

• Korean Journal of Optics and Photonics
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• v.31 no.2
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• pp.59-70
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• 2020

We discuss a modified numerical model based on the Monte Carlo radiative transfer (MCRT) method, i.e., the MCRT matrix method, for the analysis of atmospheric scattering effects in three-dimensional flash LIDAR systems. Based on the MCRT method, the radiative transfer function for a LIDAR signal is constructed in a form of a matrix, which corresponds to the characteristic response. Exploiting the superposition and convolution of the characteristic response matrices under the paraxial approximation, an extended computer simulation model of an overall flash LIDAR system is developed. The MCRT matrix method substantially reduces the number of tracking signals, which may grow excessively in the case of conventional Monte Carlo methods. Consequently, it can readily yield fast acquisition of the signal response under various scattering conditions and LIDAR-system configurations. Using the computational model based on the MCRT matrix method, we carry out numerical simulations of a three-dimensional flash LIDAR system operating under different atmospheric conditions, varying the scattering coefficient in terms of visible distance. We numerically analyze various phenomena caused by scattering effects in this system, such as degradation of the signal-to-noise ratio, glitches, and spatiotemporal spread and time delay of the LIDAR signals. The MCRT matrix method is expected to be very effective in analyzing a variety of LIDAR systems, including flash LIDAR systems for autonomous driving.

• The Korean Journal of Mycology
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• v.34 no.2
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• pp.79-83
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• 2006

This study was made to investigate the difference of the shiitake productivity according to the use of sawdust, plug-shaped and liquid spawn. Contamination of medium was confirmed by eye. There was no contamination in the liquid spawn treatment. And, contamination rates in the sawdust spawn and plug-shaped spawn were 6.7%, respectively. Productivity of fruit-bodies was 725.1 g from sawdust spawn, 726.2 g from plug-shaped spawn and 573.9 g from liquid spawn until 3rd flushing of fruit-bodies. The number of fruit-bodies was 57.4 per medium of sawdust spawn, 64.3 plug-shaped spawn and 45.1 liquid spawn. At yield per medium, the percentage of media producing over 1,000 g was 13% in plug-shaped spawn and 7% in liquid spawn. However, there was no medium producing over 1,000 g of fruit-bodies in sawdust spawn. Fruit-bodies of $600{\sim}900g$ were yielded from 79% of sawdust spawn treatment, 53% plug-shaped spawn and 33% liquid spawn treatment. When compared the productivity of fruit-bodies, liquid spawn treatment appeared lower than sawdust spawn and plug-shaped spawn treatment at 1st flushing, but appeared higher than the others at 2nd and 3rd flushing.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1635-1641
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• 1999

Bacillus subtilis PCA20-3 was isolated from meju and was found to produce a protease. The strain produced the maximum amount of enzyme in the medium containing soytone (0.2%), soluble starch (2%), $(NH_4)_2SO_4\;(0.1%),\;CaCl_2(0.1%),\;yeast\;extract\;(0.01%),\;K_2HPO_4\;(0.1%),\;and\;KH_2PO_4\;(0.1%)$. Protease was first concentrated by ammonium sulfate (80% saturation, w/v) precipitation of culture supernatant. Then the enzyme was purified by column chromatography using CM Sephadex C-50. The collected proteins were rechromatographed using Sephadex G-100 gel filtration column. The fraction with protease active from Sephadex G-100 gel chromatography was found to be pure when examined by SDS-polyacrylamide gel electrophoresis and YMC-pak reverse phase chromatography. Specific activity, yield and purity were 76 U/mg. 2.7%, and 7.6 fold, respectively. The molecular weight of the enzyme was estimated to be 31.5 kDa by SDS-PAGE. The number of amino acids calculated from molecular weight was evaluated about 321 residues. N-terminal sequence of the enzyme was $Val^1-Pro^2-Tyr^3-Gly^4-Val^5-Ser^6-Gln^7-Gly^8-Lys^9-Ala^{10}$.