• Journal of Korean Neurosurgical Society
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• v.56 no.6
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• pp.482-487
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• 2014

Objective : We assessed the life-time prevalence (LTP) of chronic low back pain (LBP) in young Korean males. We also evaluated the relationship between lumbar spinal lesions and their health related quality-of-life (HRQOL). Methods : A cross-sectional, self-reported survey was conducted in Korean males (aged 19-year-old) who underwent physical examinations for the conscript. We examined 3331 examinees in November 2014. We included 2411 subjects, who accepted to participate this study without any comorbidities. We interviewed using simple binary questions for their LBP experience and chronicity. HRQOL was assessed by Short-Form Health-Survey-36 (SF-36) in chronic LBP and healthy control groups. Radiological assessment was performed in chronic LBP group to determine whether there were any pathological causes of their symptoms. Results : The LTP of chronic LBP was 13.4%. Most (71.7%) of them didn't have any lumbar spinal lesions (i.e., non-specific chronic LBP). The SF-36 subscale and summary scores were significantly lower in subjects with chronic LBP. Between specific and non-specific chronic LBP group, all physical and mental subscale scores were significantly lower in specific chronic LBP group, except mental health (MH) subscale score. In MH subscale and mental component summary score, statistical significant differences didn't appear between two groups (p=0.154, 0.126). Conclusion : In Korean males 19 years of age, the LTP of chronic LBP was 13.4%, and more than two-thirds were non-specific chronic LBP. Chronic LBP had a significant impact on HRQOL. The presence of lumbar spinal pathoanatomical lesions affected mainly on the physical aspect of HRQOL. It influenced little on the mental health.

• Advances in aircraft and spacecraft science
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• v.2 no.1
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• pp.95-108
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• 2015

Automatic Dependent Surveillance Broadcast (ADS-B) is quickly being adopted by aviation safety authorities around the world as the standard for aircraft tracking. The technology provides the opportunity for live tracking of aircraft positions within range of an ADS-B receiver stations. Currently these receiver stations are bound by land and local infrastructural constraints. As such there is little to no coverage over oceans and poles, over which many commercial flights routinely travel. A low cost space based ADS-B receiving system is proposed as a constellation of small satellites. The possibility for a link between aircraft and satellite is dependent primarily on proximity. Calculating the likelihood of a link between two moving targets when considering with the non-periodic and non-uniform nature of actual aircraft flight-paths is non-trivial. This analysis of the link likelihood and the performance of the tracking ability of the satellite constellation has been carried out by a direct simulation of satellites and aircraft. Parameters defining the constellation (satellite numbers, orbit size and shape, orbit configuration) were varied between reasonable limits. The recent MH370 disappearance was simulated and potential tracking and coverage was analysed using an example constellation. The trend of more satellites at a higher altitude inclined at 60 degrees was found to be the optimal solution.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1484-1490
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• 2013

A lack of investigation in specific regions has impeded the understanding of epidemiological trends in the prevalence of sexually transmitted infections (STIs) in South Korea. To help fill this research gap, this study used multiplex polymerase chain reaction (mPCR) to determine the prevalence of STIs detected in clinical specimens collected from women in Cheonan, South Korea between August 2006 and November 2012, and analyzed the prevalence of STIs according to age, bacterial pathogen, and time period. Of the 1,618 specimens collected from 1,523 patients, 536 (35.2%) tested positive for at least 1 pathogen, with 407 (25.2%) testing positive for 1 pathogen, 103 (6.4%) for 2 pathogens, 20 (1.2%) for 3 pathogens, and 6 (0.4%) for 4 pathogens (n = 697 pathogens total). The median ages of all patients and of STI-positive patients were 37.8 and 33.3 years, respectively, and both decreased annually over the study period. Mycoplasma hominis (MH) was detected in 62.1% of the positive specimens, Ureaplasma urealyticum (UU) in 28.4%, Chlamydia trachomatis (CT) in 23.1%, Trichomonas vaginalis (TV) in 7.8%, Mycoplasma genitalium (MG) in 6.5%, and Neisseria gonorrhoeae (NG) in 2.1%. Whereas the prevalence of MH, MG, and TV infection did not vary greatly over the study period, that of UU decreased by one-fifth and that of both CT and NG increased 4-fold. The results indicate great variability in the rates of infection with each pathogen and a decreasing trend in overall STI prevalence, age of patients seeking STI testing, and age of STI-positive patients.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.478-480
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• 2001

Fe-base amorphous films exhibit large saturation magnetostriction and soft magnetic Properties, which make them suitable for strain sensor applications. Most important material properties for the performance of these elements are the superior soft magnetic properties, such as high permeability and small coercive force, as well as magnetoelastic properties. It is well known that the strain generated in film deposition and/or post-heat treatment processes is one of important material properties, which effects on the soft magnetic properties of the film via magnetoelastic coupling. In this study, the effect of an isotropic strain in plane of magnetic films have been performed experimently. Amorphous films with the composition of (F $e_{90}$ $Co_{10}$)$_{78}$S $i_{l2}$ $B_{10}$ were employed in this study. The film with 5${\mu}{\textrm}{m}$ thick was deposed onto the polyimide substrate with 50${\mu}{\textrm}{m}$ thick by virtue of RF sputtering. The film was subject to post annealing with a static magnetic field with 500Oe magnetic field intensity at 35$0^{\circ}C$ for 1 hour. The polyimide substrate with the film was bonded with an adhesive on PZT piezoelectric substrate with 600${\mu}{\textrm}{m}$ thick in applying voltage of 500V. The change in MH loops of films due to the isotropic strain was measured by using VSM. The coercive force was evaluated from MH loops. It has shown in the results that M-H loops of films are subject to change considerably with a dc voltage, resulting of the magnetization rotation from normal to plane direction as the applied voltage is changed from 500V to 250V.50V.V.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.2
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• pp.85-90
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• 2018

For the recovering rare earths in the spent nickel-metal hydride batteries, 10 M NaOH is added to the solution leached with sulfuric acid. The rare earth powders were precipitated at rate of 98 % at the condition of pH 2.0 or less. The recovered rare earth complex precipitate increased the leaching rate to nitric acid by heat treatment at $800^{\circ}C$ for 4 hours. Subsequently secondary precipitation was performed by adding oxalic acid to the solution in which the rare earth complex precipitate was dissolved. The re-precipitated rare earth powders were converted into oxide form through heat treatment at $800^{\circ}C$ for 4 hours with purity of 99.5 %.

• Journal of Hydrogen and New Energy
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• v.7 no.2
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• pp.157-164
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• 1996

The AB5-type metal hydride electrodes using $(LM)Ni_{4.49}Co_{0.1}Mn_{0.205}Al_{0.205}$(LM : Lanthaniumrich Mischmetal) alloy powders(${\leq}200$mesh) which were coated with 25wt% copper in an acidic bath were prepared with or without addition of 10wt% PTFE as a binder. Prior to electrochemical measurements, the electrodes were sintered at $40^{\circ}C$ for 1 and 2hrs in vacuum with Mm(mischmetal) and sponge type Ti getters. The properties such as maximum capacity, cycle life and mechanical strength of the negative electrode have been investigated. The surface analysis of the electrode was also obtained before and after charge-discharge cycling using scanning electron microscope(SEM). From the observations of electrochemical behavior, it was found that the sintered electrode shows a lower maximum discharge capacity compared with non-sintered electrode but it shows a better cycle life. For the both electrodes with or without addition of PTFE binder, the values of mechanical strength were obtained, and their values increased with increasing sintering time. However, there is little difference of discharge capacity for both electrodes.

• The Plant Pathology Journal
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• v.21 no.3
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• pp.262-269
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• 2005

An antiviral producing bacterial strain was isolated from a ginseng rhizosphere in Kangwon province of Republic of Korea. In order to identify the bacterial strain, microbiological, physiological and biochemical tests were performed, along with RAPD, 16S rRNA, 16S-23S rRNA ITS (intergenic spacer region) and DNA-DNA hybridization analyses. The bacterium was found to be a strain of Pseudomonas fluorescens, which was designated as Gpf01. The strain was grown in Muller-Hinton (MH) broth, and the culture supernatant obtained was filtered through a $0.45{\mu}l$ filter. It was further boiled at $100^{\circ}C$ and tested in two experiments for its ability to control a yellow strain of Cucumber mosaic virus (CMV-Y). In the first experiment, boiled culture filtrate (RCF) was treated on one half of the leaves of Chenopodium amaranticolor followed by CMV- Y inoculation on both halves. In the second experiment, BCF was treated on the lower leaves of Nicotiana tobacum var. Xanthi-nc, with the CMV-Y mechanically inoculated onto the upper untreated leaves. In the first experiment, BCF treatment was able to considerably reduce the number of viral lesion, and in the second experiment, plants treated with BCF showed no visible viral symptoms compared to the Muller-Hinton (MH) media treated controls 15 days post inoculation (dpi), and remained symptomless throughout the study period. Thus, Gpf01, identified as P. fluorescence, was able to produce an antiviral component in the culture filtrate, which was found to be heat stable, non-phytotoxic and effective in local as well as systemic hosts of CMV.

• The Plant Pathology Journal
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• v.19 no.5
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• pp.260-265
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• 2003

Gummy stem blight caused by Didymella bryoniae occurs exclusively in cucurbits. This fungus has been known not to produce its pycnidium in vitro unless irradiated. In this study, cultural conditions for the mass-production of pycnidiospore by Metal Halide (MH) lamp irradiation were maximized. The mycelia were cultured at $26^{\circ}C$ on PDA for 2 days under dark condition, and then the plate was illuminated with MH lamp continuously for 3-4 days at $26^{\circ}C$. Results show that a great number of pycnidia were simultaneously formed. The pycnidiospores produced were then used as immunogen. Fusions of myeloma cell (v-653) with splenocytes from immunized mice were carried out. Two hybridoma cell lines that recognized the immunogen D. bryoniae were obtained. One monoclonal antibody (MAb), Dbl, recognized the supernatant while another MAb, Db15, recognized the spore. Two clones were selected which were used to produce ascite fluid of the two MAb, Dbl and Db15, the immunotypes of which were identified as IgG1 and IgG2b, respectively. Titers of MAb Dbl and MAb Db15 were measured and the absorbance exceeded 0.5 even at a $10^{-5}$ dilution. The MAbs reacted positively with D. bryoniae but none reacted with other viral isolates, Cucumber mosaic virus and Cucumber green mottle mosaic virus. Sensitivity of MAb was precise enough to detect spore concentration as low as $10^{-3}$/well by indirect ELISA. Characterization of the MAbs Dbl, Db15 antigen by heat and protease treatments, which suggests that the epitope recognized by these two MAbs was glycoprotein.

• Journal of Hydrogen and New Energy
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• v.9 no.2
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• pp.65-75
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• 1998

Five different processes were selected and tested to find an useful method of manufacturing Fe-Ti type electrode. Initially, FeTi alloy was prepared by melting in plasma arc furnace and then powdered for shaping. Electroless Ni plating on these powder particles before shaping improved the discharge characteristics. The effects of heat-treatments on the electrode characteristics were also investigated. The discharge capacities of electrods were increased with the increasing heat-treatment temperatures. When heat treated at $1000^{\circ}C$ after shaping, the best results were acquired in the discharge capacity and cycle life. Both electroless Ni plating and heat-treatment were appeared to be crucial for the performance improvement of FeTi type electrode. Fe-Ti -Mn electrodes were prepared according to the process suggested in this study and tested to verify the promising effects of that.

• Journal of Hydrogen and New Energy
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• v.6 no.1
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• pp.1-9
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• 1995

$V_{0.9}Ti_{0.1}$ 합금은 많은 양의 수소를 흡수할 수 있으나 KOH 전해질내에서 방전이 되지 않기 때문에 Ni-MH 전지의 음극재료로 사용할 수 없었다. 이와 같은 $V_{0.9}Ti_{0.1}$ 합금을 전해질내에서 수소흡수/방출에 대한 촉매효과를 갖도록 Ni 분말과 소결하였다. Ni 분말과 소결한 모든 시편은 KOH 전해질내에서 10 Cycle 이내에 활성화 되었다. 방전용량은 소결시 첨가된 Ni 분말의 양에 따라 maximum 거동을 보였다. 가장 높은 방전용량을 보여준 전극의 경우는 소결시 첨가된 Ni 분말의 양이 25wt.%이며 그 방전용량은 302mAh/g이었다. SEM과 EDS 그리고 XRD 분석결과 소결시 $VNi_3$가 형성됨을 알 수 있었다. $V_{0.9}Ti_{0.1}$ 합금의 표면에 형성된 $VNi_3$는 전극의 최적방전조건과 밀접한 관련이 있음을 알 수 있었다. Brewer-Engel 이론에 의하면 $VNi_3$는 수소의 evolution에 대한 전기적 촉매효과가 매우 높다고 보고하고 있으며, 이러한 효과는 본 실험결과 교환전류밀도의 증가와 방전시 과전압의 감소로써 나타났다. 본 연구에서는 수소의 저장용량은 크나 KOH 전해질내에서 방전되지 않는 합금을 사용하여 Ni-MH 전지용 음극개발을 하기 위해 Ni분말과 소결하여 합금의 표면을 변화시키는 새로운 방법을 제안하고자 한다.