• 천문학회보
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• 제41권1호
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• pp.41.2-41.2
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• 2016

The follow-up BVRI photometric observations of NSVS 1461538, which was discovered as an $Algol/{\beta}$ Lyr eclipsing variable by Hoffman, Harrison & McNamara (2009), were performed for three years from 2011 to 2013 by using the 61-cm telescope and CCD cameras of Sobaeksan Optical Astronomy Observatory (SOAO). New light curves have deep depths both of the primary and secondary eclipses, rounded shapes outside eclipses and a strong O'Connell effect, indicating that NSVS 1461538 is a typical W UMa close binary system rather than an $Algol/{\beta}$ Lyr type binary star. A period study with all the timings shows that the orbital period may vary in a sinusoidal way with a period of about 5.6 yr and a small semi-amplitude of about 0.008 d. The cyclical period variation was interpreted as a light-time effect due to a tertiary body with a minimum mass of $0.66M{\odot}$. The first photometric solution with the Wilson-Devinney binary model shows that the system is a W-subtype contact binary with the mass ratio ($q=m_c/m_h$) of 3.46, orbit inclination of 85.6 deg and fill-out factor of 30%. From the existing empirical relationship between parameters, the absolute dimension was estimated. The masses and radii of the component stars are $0.28M{\odot}$ and $0.71R{\odot}$ for the less massive but hotter primary star, respectively, and $0.96M{\odot}$ and $1.21R{\odot}$ for the more massive secondary, respectively. Possible evolution of the system is discussed in the mass-radius and the mass-luminosity planes.

• Pediatric Infection and Vaccine
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• 제22권3호
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• pp.131-135
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• 2015

Since April 2012, more than 1,600 laboratory-confirmed human infections with Middle East Respiratory Syndrome Coronavirus (MERS-CoV) have been reported, occurring primarily in countries in the Arabian Peninsula; the majority in Saudi Arabia. The MERS outbreak in Korea, which began in May 2015 through the importation of a single case who had recently traveled to Bahrain, the United Arab Emirates, Saudi Arabia, and Qatar. As of November 28th, 186 secondary and tertiary cases had been reported; 38 deaths, mainly associated with underlying chronic illnesses, were reported. One case was exported to China and has been recorded as the first MERS case in China. Thirty-seven confirmed cases were associated with the index case, who was hospitalized from May 15 to May 17. Emergency room at one of the nation's largest hospitals had been affected by hospital-to-hospital and intra-hospital transmissions of MERS-CoV, resulting in an outbreak of 90 infected patients. The vast majority of 186 confirmed cases are linked to a single transmission chain associated with health facilities. The median age of patients is 55 years, with a range of 16 to 87 years. The majority (61%) of patients are men. Twenty-five (14%) of the cases involve healthcare workers. The overall median incubation period was six days, but it was four days for secondary cases and six days for tertiary cases. There has been no evidence of airborne transmission and sustained human-to-human transmission in communities. Intensified public health measures, including contact tracing, quarantine and isolation of all contacts and suspected cases, and infection prevention and control have brought the MERS-CoV under control in Korea. Since 4 July no new cases have been reported.

• Current Photovoltaic Research
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• 제9권3호
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• pp.84-95
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• 2021

The power conversion efficiency of Cu₂ZnSnSe₄ (CZTSe) solar cells depends on the absorber layer thickness; however, changes in the characteristics of the cells with varying absorber layer thickness are unclear. In this study, we investigated the changes in the characteristics of CZTSe solar cells for varying absorber layer thickness. Five absorber thicknesses were employed: CZTSe1 2.78 ㎛, CZTSe2 1.01 ㎛, CZTSe3 0.55 ㎛, CZTSe4 0.29 ㎛, and CZTSe5 0.15-0.23 ㎛. The efficiency of the CZTSe solar cells decreased as the absorber thickness decreased, resulting in power conversion efficiencies of 10.45% (CZTSe1), 8.67% (CZTSe2), 7.14% (CZTSe3), 3.44% (CZTSe4), and 1.54% (CZTSe5). As the thickness of the CZTSe absorber layer decreased, the electron-hole recombination at the grain boundaries and the absorber-back-contact interface increased. This caused an increase in the current loss, owing to light loss in the long-wavelength region. In addition, as the thickness of the CZTSe absorber layer decreased, more ZnSe was produced, and the resulting defects and defect clusters led to an open-circuit voltage loss.

• Journal of Photoscience
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• 제9권2호
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• pp.197-200
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• 2002

UVR-induced immunosuppression contributes to skin cancer. The aim was to construct accurate dose response curves for primary and secondary contact sensitivity for solar-simulated UVR (ssUVR; 290-400nm), UVA and UVB as the role of UVA in immunosuppression is controversial. We used a xenon arc source. The mice were immobilised, enabling accurate dosing. C57BL/6 mice were immunosuppressed at half the dose of ssUVR required to cause sunburn but not by higher doses (up to the sunburn dose). Thus, ssUVR causes systemic immunosuppression only over a narrow, low dose range. UVA caused suppression at low but not high doses whereas UVB induced immunosuppression at all doses tested. 8 weeks later the mice were resensitised to assess tolerance. Mice exposed to the minimum immunosuppressive dose of ssUVR prior to primary sensitisation were tolerant to re-sensitisation. However, at higher doses of ssUVR, these mice were protected from tolerance. Interestingly, while low doses of UV A caused immunosuppression, even lower doses enhanced the response to the second sensitisation. Higher doses of UVA had no affect. UVB induced tolerance in a dose related manner. Thus, ssUVR only induces immunosuppression and tolerance over a narrow dose range. Both UVA and UVB are immunosuppressive at this dose, while higher doses of UVA protect from the suppressive effects of UVB. Surprisingly very low doses of UVA enhanced memory development. Thus UVR has complex effects on the immune system depending on dose and spectrum.

• 대한치과보철학회지
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• 제29권3호
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• pp.55-74
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• 1991

The purpose of this study was to investigate the influence of early functional load around osseointegrated titanium implants. 24 titanium plasma spray coated implants (ITI HS-type) were placed into the previously extracted site in the mandible of six adult dogs. The implants were divided into three groups : the control group was the implants without abutment during the experimental period; the experimental group I was loaded by connecting the contoured abutment after 6 weeks of healing; the experimental group II was loaded after 12 weeks of healing: and the mandibular second premolar and surrounding tissues were selected for natural tooth group to compare the implanted group. All dogs were injected intravenously tetracycline, alizarin red S, and calcein for bone labeling. After the experimental period of 18 weeks, the dogs were sacrificed and longitudinal sections of the bone-implant interface were cut and observed using light microscope, scanning electron microscope, and fluorescence microscope. The results of the study were as follows: 1. Light and scanning electron microscopically, all implant surfaces were well contact with bone tissue at the cortical layer, but some areas of cancellous bone were not contact directly. 2. Fluorescence microscopically, number and size of the new secondary osteons around the implant were increased than those of the natural tooth. 3. Fluorescence microscopically, linear and concentrical fluorescence was observed at or near the surface of all implants, and the bone formation and remodeling of the implants loaded after 6 week of healing were great, and unloaded implants were worst. 4. Fluorescence microscopically, endosteal bone formation was greater than periosteal bone formation at or near the implants. 5. Fluorescence microscopically, number and size of linear and concentric fluorescence was increased at the lingual side than the buccal side of the loaded implants. The result of the study indicate the possibility of the early load to the implant via a prosthesis.

• 대한후두음성언어의학회지
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• 제27권1호
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• pp.45-50
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• 2016

Background and Objectives : This study aims to conduct post-voice therapy to patients with unilateral vocal fold paralysis for vocal improvement, motility recovery and analyze the results. Materials and Methods : Voice therapy was conducted to 13 patients who had shown response to voice therapy amongst 98 patients diagnosed with unilateral vocal fold paralysis. In order to be able compare before and after perceptual, acoustic and aerodynamic evaluations were conducted after voice therapy. Also, by using dysphagia checklist, we have verified whether if the patient had dysphagia prior to voice therapy. The therapy was conducted by improving the larynx movement and glottal contact, whilst removing hypertension of the supraglottic. Results : All 13 patients who underwent voice therapy had shown improvements that are statistically significant from 4 scales excluding the S scale from auditory perception evaluation (p<0.05), with enhanced glottal contact. In acoustic evaluation, Jitter, Shimmer and NHR had shown significant improvement after voice therapy. MPT was also notably improved among aerodynamical evaluation (p<0.001). All 11 patients had with dysphagia prior to voice therapy reported to have improved swallowing functions. Conclusion : Application of adequate voice therapy to patients with unilateral vocal fold paralysis, is an effective method that might be employed in the initial phase. Especially, the voice therapy proposed in this study is expected to be useful for patients in hypertension status due to secondary compensation after initial paralysis, since it focuses on improving vocal symptoms in a calm state with the supraglottis sufficiently relaxed. Also, the therapy is expected to be effective for improving swallowing functions.

• 대한의용생체공학회:의공학회지
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• 제27권6호
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• pp.323-331
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• 2006

The purpose of this study was to investigate the effect of performing a cognitive task during treadmill walking on the stride rate variability. Ten university students(age $24.0{\pm}0.25$, height $172{\pm}3.1cm$, weight $66{\pm}5.3kg$) were participated in dual task experiments which consist of both walking alone and walking with a cognitive task. Two-back task was selected for the cognitive task since it did not have learning effect during the experimental procedure.3D motion analysis system was used to measure subject's position data by changing walking speed with 4.8, 5.6, 6.4, 6.8, and 7.2 km/hr. Stride rate was calculated by the time between heel contact and heel contact. Accuracy rate of a cognitive task during walking, coefficient of variance, allometric scaling methods and Fano factor were used to estimated the stride rate variability. As the walking speed increased, accuracy rate decreased and the logarithmic value of Fano factor increased which showed the statistical difference. Thus it can be concluded that the gait control mechanism is distracted by the secondary attention focus which is the cognitive task ie. two-back task. Further study is needed to clarify this by increasing the number of subject and experiment time.

• 한국학교ㆍ지역보건교육학회지
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• 제9권2호
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• pp.1-13
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• 2008

Objectives: Literature has shown the relationship between the use of harmful media and sexual behaviors among adolescents. Laws and regulations of violent and sexual mass media are getting stricter, but young children reported that they were still accessible to these harmful materials. It might be due to the development of new techniques in media delivery and new trends of game addict among Korean adolescents. Since there were very few studies on recent harmful media available to young children, the authors explore the usability of harmful media and identify related factors that can predict adolescent sexual attitudes and activities. Methods: This study was conducted secondary analysis using the internal data that were drawn from National Youth Committee's survey of adolescent harmful environment in 2007. The self-reported questionnaires were administered to 13,721 adolescents who were randomly selected based on strata of geography, school, and gender. Results: Adolescents accessed mostly to NC-19(No Children under 19) TV programs(35.8%) and AO(Adult Only) games(35.5%). Most of them reported that they did not have difficulty in the contact of these harmful media. The factors that can predict adolescent sexual intercourse are male adolescents, attending high school, not being satisfied with family life and school, contact with phone-advertising of sex, AO games and other online games, viewing adult videos, or reading adult books. Conclusions: When sex education is designed, an instructor considers not only students' demographic characteristics but also the strategies to deter the use of harmful media especially for game materials.

• 동의생리병리학회지
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• 제26권6호
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• pp.947-952
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• 2012

This Study was conducted to investigate Muscle Test of Point Selection through CRA(Contact Reflex Analysis) Muscel Diagnosis. So this study used to compare and analyze the effects of Muscel(Deltoid Muscel of Posterior) RMS(Root Mean Squared) and MEF(Median Edge Frequency) Among Groups that do not respond to questionnaire, Tonguibogam Naegyeongpyeon Small Intestine Group, Small Intestine MeridianPathway Primary Symptom and Secondary Symptom Group and Kwanwon(CV4) meridian Principal action Group. The questionnaire is composed of 23 items. The questionnaire was intended to elicit information on assorting into 4 groups. After Survey, Subject had to Muscle test subjects. Muscle experimental methods are as follows: Holding the shoulder without contacting Kwanwon. Holding the shoulder contacting Kwanwon. The first iteration. Group 1,2,3 were increased sEMG RMS compared with First experiment and Second experiment. Group 4(Including Uterus and Intestinal Flora Problem) were decreased sEMG RMS compared with First experiment and Second experiment. This test means that it is similar to diagnosis CRA and Small intestine channel of hand taiyang muscle, not Small Intestine MeridianPathway. It is suggested that subjects with a Small Intestine problem(Uterus and Intestinal Flora Problem) shows the results of decreasing posterior Deltoid Muscular strength. It means that CRA muscle diagnosis is associated with Alarm points diagnosis. But it doesn't consider influence of fat on the surface EMG.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.204-204
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• 1999

The plasma source ion implantation(PSII) technique which is a method using high negative voltage pulse in plasma system has the potential to change the surface properties of polymer. PSII technique increase the surface free energy by introducing polar functional groups on the surface so that it improves reactivity, hydrophilicity, adhension, biocompatability, etc. However, the mobility of polymer chains enables the modified surface layers to adapt their composition to interfacial force. This hydrophobic recovery interrupts the stability of modified surfaces to keep for the long time. In this study, poly(methyl methacrylate)(PMMA), poly(2-hydroxyethyl methacrylate)(PHEMA), and polu(2-hydroxypropyl methacylate)(PHPMA) for contact lens application, were modified to improve the wettability with PSII technique and were investigated the surface stabilities. Polymer film was prepared with solution casting(3 wt.% solution) and was annealed at 11$0^{\circ}C$ under vacuum oven to remove solvent completely and to eliminate physical ageing. The thickness of the film measured by scanning electron microscopy (SEM) and surface profilometer was about 10${\mu}{\textrm}{m}$. Polymers were treated with different kinds of gases, pulse frequency, pulse with, pulse voltage, and treatment time. Even though PMMA, PHEMA, and PHPMA have similar repeat unit structure, the optimal treatment conditions and the tendency to hydrophobic recovery were different. PHPMA, more hydrophilic polymer than PMMA and PHEMA showd better wettability and stability after mild treatment. Surface tensions were obtained by water and diiodomethane contact angle measurements to monitor the relation between hydrophobic recovery and polymer structure. Different ion species in plasma change the polar component and dispersion component of polymer surface. For better wettability surface, the increase of polar component was a dominant factor. We also characterized modified polymer surfaces using x-ray photoelectron spectroscopy(XPS), secondary ion mass spectrometry(SIMS), Fourier Transform infrared spectroscopy(FT-IR), and SEM.