• Korean Journal of Veterinary Service
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• v.21 no.4
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• pp.451-465
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• 1998

The present study was carried out to investigate the prevalence of brucellosis in Kyungbuk area for the 3 years from 1966 to 1998. Collective milk samples were routinely screened to detect positive farms by using the milk ring test(MRT), and serum agglutination test was performed to detect sero-positive individuals in the MRT positive farms. Attempt were made to isolate the causative organismas from slaughtered sero-positive reactors and some biochemical and polymerase chain reation characters of the isolates were also made to identify the organisms. Seroprevalence to brucellosis in peoples who are close contact with infected dairy herds was also investigated. Brucellosis of dairy cattle was rare before 1997, but has been broken more frequently since early 1998. By the MRT for dairy herds, positive rate was gradually increased every year : 0.6% in 1996, 1.5% in 1997, 3.9% in 1998. Among 262 MRT-positive herds, only 21 herds(8.0%) showed positive brucellosis in serological test. The isolation rates of Brucella sp from tested materials were 51.2% in supramammary glands, 39.5% in milks, and 50.0% in pulmonary Iymphnode, respectively. Isolated strain and biotype were Brucella(B) arbortus biotype 1 in 26 heads, and were B suis biotype 1 in 2 heads. Isolated strain and vaccine strain were very similar in their colony morphology and staining. In drug susceptibility, isolated stains(B abortus) and vaccine strain(B abortus RB-51) were sensitive to ampicillin, gentamycin, kanamycin, neomycin, penicillin, streptomycin, and to tetracycline, but resistant to erythromycin. In the PCR, field strains reacted to BA and IS711 primers, and vaccine strain reacted to BA, IS711, and RB5l primers. In the plate agglutination test of 96 sera of human contacted with animals, serum antibody titer detected 1 : 100 in one person, 1 : 200 in one, and below 1 : 25 in the others.

• Environmental and Resource Economics Review
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• v.16 no.3
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• pp.683-699
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• 2007

This study applied the choice experiment (CE) method to measure values of statistical lives from multi-attributed mortality risk reduction choices. The four characteristics of mortality risk (i.e. cause of death, voluntariness of mortality risk, timing of death, magnitude of mortality risk reduction) are utilized to design the alternatives of choice sets. The estimation results for the multinomial logit model show that individuals are willing to pay 27,930 won per year for a change from the status quo to a $\frac{1}{100}$ mortality risk reduction for 10 years, 116,773 won per year for mortality risk reduction associated with adults, 97,682 won per year for voluntary mortality risk reduction, 77,234 won per year for involuntary mortality risk reduction. There were several estimates of VSL related to different attributes of mortality risk. The mean VSLs of infant/child/young adult ranged from 1,165 million won to 1,367 million won. The mean VSLs ranged from 1,631 million won to 1,833 million won for adult, and were between 1,128 million won and 1,330 million won for old person.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.935-942
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• 2007

The stem bark of Rhus verniciflua (RVSB) has been used in herbal medicine to treat diabetes mellitus and stomach ailments for thousands of years in Korea, despite its content of the plant allergen, urushiol. A new biological approach for the removal of urushiol from RVSB using mushrooms is described. All mushroom species (11 sp.) employed in this study were able to grow on RVSB, although the growth rate (mm/day) was lower than the control (sawdust). The components of urushiol congeners [C15 triene (m/z 314), C15 diene (m/z 316), C15 monoene (m/z 318), and C15 saturated (m/z 320)] were purified by HPLC and identified by GC-MS. A C15:3 (3-pentadecatrienly catechol) was found to be most abundant in RVSB. Urushiol analogues decreased remarkably from 154.15 to 10.73 mg/100 g (approximately 93%) by Fomitella fraxinea, whereas Trametes vercicolor showed only a 1.46% degradation capacity despite its 2 fold higher growth rate. Similarly, laccase activity was found to be high for F. fraxinea and low for T. vercicolor. Moreover, approximately 98% detoxification was accomplished by F. fraxinea cultivated on RVSB supplemented with 20%(w/w) rice bran. These findings suggest that mushrooms can be used in the detoxification of RVSB.

• Korean Journal of Environmental Biology
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• v.20 no.4
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• pp.325-338
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• 2002

The distribution and standing crop of phytoplankton were investigated at 12 stations of Songjiho, Ssangho, Maeho and Hyangho as of four lagoons in the east coast from May to November, 2001. It turned out to be total of 164 taxa, and classified as four phylums, four classes, 14 orders, 20 families, 59 genera, 139 species, 22 varieties, two forms and 1 unidentified species by Engler's classification system. Among 104 taxa, 16 taxa including Oscillatoria chlorina were identified as indicators of water pollution and only Cocconeis placentula was the indicator of the clean water. Standing crops of all stations investigated appeared to be relatively high values. Based on the present study upon the distribution and standing crop of phytoplankton, it is regarded as the state of the eutrophication in Songjiho, Ssangho, Maeho and Hyangho as of four lagoons in the east coast.

• KSBB Journal
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• v.22 no.4
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• pp.218-221
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• 2007

The polyene antifungal antibiotics, mostly produced by Gram-positive soil actinomycetes, are a family of type I polyketide macrolide ring compounds with 20$\sim$40 carbon backbone contain 3$\sim$8 conjugated double bonds. Using polyene-specific genomic screening strategy, we previously isolated three novel polyene-producing actinomycetes strains from soil, implying the potential application of these strains' spores as microbial pesticides. Here, we report that the sonication is a very efficient method for actinomycetes spore generation with a sonicator power-dependent manner. In addition, these sonication-driven actinomycetes spores retained significant portion of their cell viabilities as well as antifungal activities after freeze-drying procedure, implying the potential application of these strains' spores as microbial pesticides.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.630-630
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• 2013

Recently, atomically smooth hexagonal boron nitride(h-BN) known as a white graphene has drawn great attention since the discovery of graphene. h-BN is a III-V compound and has a honeycomb structure very similar to graphene with smaller lattice mismatch. Because of strong covalent sp2bonds like graphene, h-BN provides a high thermal conductivity and mechanical strength as well as chemical stability of h-BN superior to graphene. While graphene has a high electrical conductivity, h-BN has a highly dielectric property as an insulator with optical band gap up to 6eV. Similar to the graphene, h-BN can be applied to a variety of field, such as gate dielectric layers/substrate, ultraviolet emitter, transparent membrane, and protective coatings. However, up until recently, obtaining and controlling good quality monolayer h-BN layers have been too difficult and challenging. In this work, we investigate the controlled synthesis of h-BN layers according to the growth condition, time, temperature, and gas partial pressure. h-BN is obtained by using chemical vapor deposition on Cu foil with ammonia borane (BH3NH3) as a source for h-BN. Scanning Transmission Electron Microscopy (STEM, JEOL-JEM-ARM200F) is used for imaging and structural analysis of h-BN layer. Sample's surface morphology is characterized by Field emission scanning electron microscopy (SEM, JEOL JSM-7100F). h-BN is analyzed by Raman spectroscopy (HORIBA, ARAMIS) and its topographic variations by Atomic force microscopy (AFM, Park Systems XE-100).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.716-722
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• 2003

This study determined the optimum dosage for coagulation reactions of red tide organisms (RTO) using a combination of ignited oyster shell powder (10sp) and loess and examined the electrokinetic and rheological characteristics of their flocs. Two kinds of RTO, Cylindrotheca closterium and Skeletonema costatum, were sampled in Masan Bay and cultured in the laboratory. Coagulation experiments were conducted using various concentrations of IOSP, loess, IOSP+1oess, RTO, and a jar tester RTO cell numbers were counted for both the supernatant and RTO culture solution. The removal rates increased rapidly with increasing IOSP concentrations up to 50 mg/L and loess concentrations up to 800 mg/L. A removal rate of $100\%$ was reached at 400 mg/L of IOSP and 6,400 mg/L of loess. The highest increment $(16.7\%)$ of the rates of coagulation reaction occurred using both IOSP and loess (50+200 mg/L) in comparison with IOSP alone. The rate of coagulation reaction using both IOSP and loess (50+200 mg/L), $90.6\%,$ was similar to employing either IOSP of 150 mg/L or loess of 3,200 mg/L. All of the coagulation liquids for RTO, IOSP (200 mg/L), loess (200 ma/L), and IOSP+1oess (200+200 mg/L) revealed non-Newtonian fluid properties and therefore their shear rate vs. shear stress curves were non-linear. The coagulation liquids revealed elastic body properties at a lower shear rate increasing in the following order: RTO, IOSP (200 mg/L), loess (200 mg/L), and IOSP+1oess (200+200 mg/L. IOSP+1oess (200+200 mg/L) especially demonstrated plastic flow properties at a lower shear rate.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.5
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• pp.91-100
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• 2009

In this paper, we propose a wearable augmented reality system using gaze interaction. Gaze interaction has been considered to be the potential of easy, natural and fast way of interaction and becomes a suitable way in optical see-through HMD based wearable AR. Our system recognizes user's gaze point, half blink motion and displays the information of object seen by user to HMD. Half blink selection technique avoids the Midas touch problem and represents user's intention correctly. We've developed a AR annotation system and estimated the usability of gaze interaction. The accuracy and robustness of our technique is verified on the experimental results.

• Proceedings of the Korean Vacuum Society Conference
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• 1995.06a
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• pp.154-154
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• 1995

The Xu-Tec process is also called the double glow surface alloying technology and is a new method of surface metallurgy which can produce an alloy layers with sp ecial phisical and chemical properties on the surface of common and inexpensive mater ials. Many super alloys and alloy steels, sueh as nickel base alloys, high speed steels and staiinless steels, have been produced by Xu-Tee Process on the surfaces of carbon steels. The depth of the alloy lasyers may vary from several microns up to 300 micr ons with alloying elements in a concentration of few percentage to 100%. World wide patents for Xu-Tec process have been granted in the United states, Canada, United Ki ngdom, Australia and Japan. High performance saw blades have been successfully produced by the Xu-Tee process with much simper processing steps and less cost than bimetal high speed saw blades. A comparison of the cutting times and wear rates of the Xu-Tee blades with the conventional bimetal blades has been made. The Xu-Tee bIases demonstrates sim ilar or better performance than bimetal blades. A Xu-Tec Unit for the commercial pr oduction of Xu-Tec saw blades has been designed and manufactured. This Unit can t reat 10,000 haek saw blades at one time. Three Xu-Tec hack saw blades production I ines have been set up in China. China.

• Journal of the Korean institute of surface engineering
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• v.36 no.1
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• pp.27-33
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• 2003

Pulsed magnetron sputtering of graphite target was employed for deposition of diamond-like carbon (DLC) films. Time-resolved probe measurements of magnetron discharge plasma have been performed. It was shown that the pulsed magnetron discharge plasma density ($∼10^{17}$ $m^{-3}$ ) is close to that of vacuum arc cathode sputtering of graphite. Raman spectroscopy was sed to examine DLC films produced at low ( $U_{sub}$ / < 1 kV) pulsed bias voltages applied to the substrate. It has been shown that maximum content of diamond-like carbon in the coating (50-60%) is achieved at energy per deposited carbon atom of $E_{c}$ =100 eV. In spite of rather high percentage of $sp^3$-bonded carbon atoms and good scratch-resistance, the films showed poor adhesion because of absence of ion mixing between the film and the substrates. Electric breakdowns occurring during the deposition of the insulating DLC film also thought to decrease its adhesion.