• Korean Journal of Organic Agriculture
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• v.15 no.1
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• pp.93-108
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• 2007

In order to find a solution to protect pigs from bacterial diarrhea and the nasty smell in stalls which are the most trouble, we composed a bio-formula with Stretococcus thermophilus, Bacillus amyloliquifaciens and Bacillu subtilis. The antagonistic microbe Bacillus amyloliquifaciens can control the growth of Salmonella typhimurium KCTC 1926, Escherichia coli O-157, Listeria and Staphylococcus. S. thermophilus from pig's stomach can live in gastric juice so it also control germs. They worked in its living cell state and its culture fluid. As a result of feeding with piglings, it showed effects of preventing diarrhea and increasing the weight.

• Journal of Veterinary Clinics
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• v.18 no.4
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• pp.324-328
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• 2001

This study was performed to evaluate the effects of $AS_2O_3$ upon antiangiogenesis in rat cornea, to examine it\`s possible application as an anticancer drug and to provide basic data for further studies of antiangiogenetic mechanism of $AS_2O_3$ . Angiogenesis was induced by cornea micropocket assay, as previously described. Sixteen of forty-eight eyes of Sprague-Dawley rats were randomly assigned to one of three groups, namely, only a bFGF group(control group), and a group treated by $AS_2O_3$ ($AS_2O_3$ group). After pellet implantation, we measured the number of new vessels, vessel length and clock hour of neovascularization, and area of neovascularization was determined using a mathematical formula. New vessels growing began at day 3, number of vessels in $AS_2O_3$ group were significantly more less than those in control group (p<0.05). The length of vessels of $AS_2O_3$ group was significantly shorter than that of control group after day 3(p<0.05). The clock hours of all group were slowly increased at all days but $AS_2O_3$ group was inhibited more than control group. Neovascularization areas of $AS_2O_3$ group were more significantly inhibited than those of control group (p<0.05). This study showed that $AS_2O_3$ had powerful antiangiogenetic effects and it would be useful in the choice of anticancer drug.

• Journal of Electrical Engineering and Technology
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• v.2 no.3
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• pp.391-395
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• 2007

MgO enhanced $(Ba_{0.6}Sr_{0.4})$ $TiO_3$ thick films have been fabricated by a tape casting and firing method for tunable devices on the microwave frequency band. In order to improve ferroelectric properties, the composite thick films enhanced with MgO on BST have been asymmetrically annealed by a focused halogen beam method. Dielectric constants of composite thick films are changed from 1050 to 1300 at 100 kHz after 60 s and 150 s annealing by the focused halogen beam. Even though no prominent changes were previously observed from the thick films before and after annealing in terms of chemical composition and surface morphology, it is clear that the average particle size of the thick films calculated by Scherrer's formula were increased by annealing. Furthermore, a strong correlation between particle size and dielectric constant of the composite thick films has been observed; dielectric constant increases with increased particle size. This has been attributed to the increased volume of ferroelectric domain due to increased particle sizes. As a result, the tuning range was improved by halogen beam annealing.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.110-117
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• 2004

The aim of a benchmark study is carried out nine methods are employed for ULS analysis which implicitly predict the ultimate strength of aluminium stiffened panels under axial compression. For this purpose, DNV PULS, experimental and numerical data on the ultimate strength of panels were collected. Comparison of these experimental / numerical, DNV PULS / numerical, results with theoretical solutions by the candidate methods is performed. Also it's compared that ALPS/ULSAP program is based on closed-form formula for the ULS of plates and grillages under axial compression. It is considered that ALPS/ULSAP methodology provides quite accurate and reasonable ULS calculations by a comparison with more refined FEA. Comparison of these experimental data, numerical, computational software results with the simplified solutions obtained by the candidate methods is then performed. The model uncertainties associated with the candidate methods are studied in terms of mean bias and COV (i.e., coefficient of variation) against experiments and numerical solutions, and the relative performance of the various methods is discussed.

• Water for future
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• v.15 no.2
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• pp.23-32
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• 1982

This study is to clarify the relation between the maximum 24 hour rainfall and the daily rainfall of a designated time 10 A.M., using the 506 rainfall datum from 32 rain-guage stations on the Han river basin covering a period of 7 years and trying to estimate the ratio of two data in accordance with the amount of rainfall respectively. The Mononobe's formula, which is widely used in this country, has the value of 2/3 power in it. The "n" was considered instead of 2/3 and derivated for each guaging station. The results make it possible to establish the Ison-n value map, and show that the n value is affected mainly by the topographical conditions. The daily rainfall of a designated time can be modified by the results of this study and expressed as Y(%)=218.25/R$$. But in the case of exceeding 200mm/day, it is recommended to use the 110% for safety. On the problems of intensity-duration concerned with the planning of public works, the formula can be expressed as r$$=fRday/24.(24/t)$$, where "f" is Y(%) divided by 100. As this study was done with the datum within shor period, it is necessary to study more about the "n" and "f" value so as to get previse value in the future.o as to get previse value in the future.

• Korean Journal of Optics and Photonics
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• v.8 no.5
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• pp.382-386
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• 1997

The composite $MgF_2$-$TiO_2$ films are fabricated by codeposition from two independent sources. To improve optical and mechanical properties of films, the films are prepared by ion-assisted deposition. Chemical compositions, optical properties and microstructures of the composite films were investigated. The chemical composition rates of Ti:Mg of $MgF_2$-$TiO_2$ composite films are nonlinearly varied according to the relative deposition rate. It is found that the refractive indices of the composite films decrease with increasing $MgF_2$ contents and can be fitted quite well with Drude's formula and that the microstructures of the composite films changes from an amorphous to crystalline with increasing $MgF_2$ mole fractions.

• Bulletin of the Korean Chemical Society
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• v.21 no.9
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• pp.882-890
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• 2000

Ab initio calculations are carried out on protonation equilibria of 5-memberedheteroaromatic aldehydes (5MHAs;heteroatom Y = NH, O, PH,and S and substituentZ = NH2, OCH3, SCH3, CH3, H, Cl, CHO, CN,NO2) at the $MP2}6-31G*$ level. Naturalbond orbital (NBO) analyses show that the optimal localized natural Lewis structures of the protonated aldehydes,(P), are ortho (C3) protonated (for Y = O, PH and S) and N-pro-tonated (for Y = NH) forms in contrast to the standard structural Lewis formula for aldehydes, (R). The delo-calizability of ${\pilone}-pairon$ the heteroatom $(n{\pi}(Y))$ is in the order Y = NH > O > S > PH. The transmission efficiency of (Z) substituent effects to the carbonyl moiety run parallel to the delocalizability of $n{\pi}(Y)$ for R,but is dominantly influenced by the cationic charge on $C{\alpha}(C{\alpha}+)$ for P, which is in the reverse order of thede-localizability of $n{\pi}(Y).$ The Hammett ${\rho}values$ for variation of Z in the protonation are determined by the dif-ference in the transmission efficiencies between Pand R stateat simple interpretation of their magnitude is not warranted. However,the magnitude of the gas-phase ${\rho}z+$ values decreases as the level ofcomputation is raised from RHF/3-21G* to RHF/6-31G* and to $MP2}6-31G*$ but increases again at the MP4SDQ/6-31G* level. Further decrease occurs when solvent effect (water) is accounted for by the SCRF method. Comparison of the SCRF ${\rho}z+values$ with those determined in the aqueous acid solution for Y = S and CHCH shows inadequacy of accounting for the solvent effects on the ${\rho}values$ by a continuum model. It is noteworthy that semiempirical calculations, especially theAM1 method, give even lower magnitude of the gas-phase ${\rho}values.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.2
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• pp.208-214
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• 2024

This reports the electrical properties of single-crystal β-gallium oxide (β-Ga₂O₃) vertical Schottky barrier diodes (SBDs) with a different guard ring structure. The vertical Schottky barrier diodes (V-SBDs) were fabricated with two types guard ring structures, one is with metal deposited on the Al₂O₃ passivation layer (film guard ring: FGR) and the other is with vias formed in the Al₂O₃ passivation layer to allow the metal to contact the Ga₂O₃ surface (metal guard ring: MGR). The forward current values of FGR and MGR V-SBD are 955 mA and 666 mA at 9 V, respectively, and the specific on-resistance (R_on,sp) is 5.9 mΩ·cm² and 29 mΩ·cm². The series resistance (R_s) in the nonlinear section extracted using Cheung's formula was 6 Ω, 4.8 Ω for FGR V-SBD, 10.7 Ω, 6.7 Ω for MGR V-SBD, respectively, and the breakdown voltage was 528 V for FGR V-SBD and 358 V for MGR V-SBD. Degradation of electrical characteristics of the MGR V-SBD can be attributed to the increased reverse leakage current caused by the guard ring structure, and it is expected that the electrical performance can be improved by preventing premature leakage current when an appropriate reverse voltage is applied to the guard ring area. On the other hand, FGR V-SBD shows overall better electrical properties than MGR V-SBD because Al₂O₃ was widely deposited on the Ga₂O₃ surface, which prevent leakage current on the Ga₂O₃ surface.

• Archives of Plastic Surgery
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• v.42 no.3
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• pp.356-360
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• 2015

In plastic surgery, patient photography is a vital component of clinical, educational, legal, and research documentation. Optimal acquisition of photographic data requires a dedicated photography studio or a three-dimensional anatomic scanner, both of which are financially impractical for most clinicians. Simplified photo standardization is proposed for use in random clinical settings by using a portable device called the Mirror Stand (MirS). This model device aims to mimic a studio environment by incorporating the basic elements of producing consistent photographs. The pilot MirS is designed for facial photography. Images of 40 random subjects were obtained using the MirS with three different cameras. Real anthropometric measurements of each subject were collected, compared with the photographic measurements, and analyzed. In this study, all three cameras produced equally reliable measurements. Actual facial measurements were comparable to the photogrammetric measurements obtained from photographs taken using the MirS. A constant formula was derived; it allowed the conversion of photographic values into real anthropometric values. The MirS produced consistent photographs with respect to the measurements. The photographs obtained could be translated reliably into their real anthropometric measurements. Therefore, the MirS can be applied in daily practice, providing an efficient alternative for obtaining a standard justifiable photograph.

• Journal of the korean Society of Automotive Engineers
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• v.5 no.2
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• pp.56-63
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• 1983

The aerodynamic characteristics of the most popular car (PONY 2) produced in Korea have been experimentally investigated by Seoul National University's wind tunnel. The model (PONY 2) chosen for the wind tunnel was a 1/5 scale of the original car without simulated underbody, cooling air flow and accessories. The measured aerodynamic drag coefficient corrected by JARI formula is 0.45 which is very close to those of small foreign cars. To see the effect of the different configurations on the aerodynamic drag, the modifications have been made by changing the hood slope and backlight slope, and putting the add-on-aerodynamic devices on the orignal shape. The rear spoiler was found the most effective one to reduce the aerodynamic drag. It may be concluded that the considerable aerodynamic drag reduction can be achieved by changing the slopes and A-O-A devices at the proper places of the car.