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        검색결과 11

        2.
        2019.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study investigates the effect of MnO2 and CuO as acceptor additives on the microstructure and piezoelectric properties of 0.96(K0.5Na0.5)0.95Li0.05Nb0.93Sb0.07O3-0.04BaZrO3, which has a rhombohedral-tetragonal phase boundary composition. MnO2 and CuO-added 0.96(K0.5Na0.5)0.95Li0.05Nb0.93Sb0.07O3-0.04BaZrO3 ceramics sintered at a relatively low temperature of 1020 oC show a pure perovskite phase with no secondary phase. As the addition of MnO2 and CuO increases, the sintered density and grain size of the resulting ceramics increases. Due to the difference in the amount of oxygen vacancies produced by B-site substitution, Cu ion doping is more effective for uniform grain growth than Mn ion doping. The formation of oxygen vacancies due to B-site substitution of Cu or Mn ions results in a hardening effect via ferroelectric domain pinning, leading to a reduction in the piezoelectric charge coefficient and improvement of the mechanical quality factor. For the same amount of additive, the addition of CuO is more advantageous for obtaining a high mechanical quality factor than the addition of MnO2.
        4,000원
        3.
        2018.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Laminate composites composed of 0.95Pb(Zr0.52Ti0.48)O3-0.05Pb(Mn1/3Sb2/3)O3 piezoelectric ceramic and Fe-Si-B based magnetostrictive amorphous alloy are fabricated, and the effect of control of the areal dimensions and the thickness of the piezoelectric layer on the magnetoelectric(ME) properties of the laminate composites is studied. As the aspect ratio of the piezoelectric layer and the magnetostrictive layer increases, the maximum value of the ME voltage coefficient(αME) increases and the intensity of the DC magnetic field at which the maximum αME value appears decreases. Moreover, as the thickness of the piezoelectric layer decreases, αME tends to increase. The ME composites exhibit αME values higher than 1 Vcm−1Oe−1 even at the non-resonance frequency of 1 kHz. This study shows that, apart from the inherent characteristics of the piezoelectric composition, small thicknesses and high aspect ratios of the piezoelectric layer are important dimensional determinants for achieving high ME performance of the piezoelectric-magnetostrictive laminate composite.
        3,000원
        4.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Menopausal status and hormonal changes are important factors related to the prevalence of metabolic syndrome in women. Nutrient intake is also a risk factor for metabolic syndrome. Although, postmenopausal status and hormonal changes result in a 60% increased risk for metabolic syndrome, there has been no method to elucidate the effects of nutrient intake on metabolic syndrome following menopause. This study was conducted to evaluate the effects of nutrient intake by menopausal women on the prevalence of metabolic syndrome. All data were obtained from the Korean National Health and Nutrition Examination Survey 2007–2009. Menopausal women showed a 1.8-fold increase in the prevalence of metabolic syndrome. Metabolic syndrome group showed significantly lower values in calcium, iron, vitamin A, carotin, retinol and riboflavin intake than those of normal group in premenopausal women. In postmenopausal women, there are significant differences in crude fiber, calcium, iron, potassium, riboflavin and niacin. Indeed, different patterns of nutrient intake were observed by menopausal status and metabolic syndrome. As menopause cannot be controlled, a diet with adequate nutrient intake may be useful to control the rapid increase in the prevalence of metabolic syndrome due to menopause.
        4,000원
        5.
        2013.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to determine which spatiotemporal gait parameters obtained during hemiplegic walking could be a predictive factor for the Timed Up and Go test (TUG). Two hundreds nine subjects who had suffered a stroke were recruited for this study. They were participated in two assessments; the TUG test and gait analysis. The relationship between the TUG test and spatiotemporal parameters was analyzed using Pearson’s correlation coefficients. In addition, to predict the spatiotemporal gait parameters that correlated most with the TUG scores, we used multiple linear regression analyses (stepwise method). The results show that the normalized velocity was strongly correlated with the TUG performance (r=-.72, p<.001). Additionally, single support percentage (SSP), double support percentage (DSP), step time difference (STD), and step length difference (SLD) significantly were correlated with the TUG test. Normalized velocity, STD, DSP of affected side, and SSP of non-affected side explained 53%, 8%, 3%, 2%, of variance in the TUG test respectively. In conclusion, an increase in gait velocity and a decrease in STD would be effective indicators of improvement on the functional mobility in the stroke rehabilitation.
        4,000원
        6.
        2013.08 구독 인증기관 무료, 개인회원 유료
        This is a miracle in movies. It’s the best shaman ritual with tears and blood through the camera. It’s Muel O’s talent to make it embracing the ordinary life not with the formalism of intellects. ‘Jiseul’ is one of the best movies this year and full of the immortal spirit. This is the review on the outcome from the minimal condition. You can imagine the outcome from more fulflling conditions. It’s time that we should fully support him who is dreaming to fly high where nobody has paid attention
        4,000원
        7.
        2011.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        After stroke, many people have problems with balance during movement. Balance is essential for the optimal functioning of the locomotor system and the performance of many activities of daily living. The Functional Gait Assessment (FGA) is a clinical tool for evaluating balance ability during walking. The test consists of ten tasks, seven tasks of the Dynamic Gait Index and three additional tasks. The purpose of this study was to evaluate the reliability and internal consistency of data obtained with the Korean version of the FGA when used with people after suffering a stroke. One-hundred participants, at least three months poststroke and able to walk at least six meters with or without a walking aid, participated in the study (age range=30~83 years; ). Two physical therapists and two physical therapy students rated the FGA. Intrarater and interrater reliability of the FGA were assessed using kappa statistic and intraclass correlation coefficients (2,1). The internal consistency of the FGA was assessed using the Cronbach alpha. The Cronbach alpha was good (=.86~.93). The intrarater (intraclass correlation coefficient=.92~.95) and interrater reliability (intraclass correlation coefficient=.91, .95) of the total scores administered by the therapists and students were good, whereas the reliability for single item scores when administered by the physical therapists was moderate to good (kapa value=.42~.97). This study found that intrarater and interrater reliability for total FGA scores and internal consistency were good. Therefore, the Korean version of the FGA can be used as a reliable tool to assess the functional gait performance of patients after stroke.
        4,000원
        8.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to understand food sources-metabolism for the pacific oyster (Crassostrea gigas), the stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) of its gut, gill, and muscle as well as potential food sources (particulate o
        4,000원
        9.
        2009.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        한국과학영재학교 천지인 천문대의 천문학적 시상 패턴에 관한 연구를 수행하였다. 관측지의 시상 상황을 결정하기 위해서는 그 관측지에서 시상을 측정하여 데이터를 얻는 것이 가장 중요함에도 불구하고, 부산 지역에서 시상에 관한 체계적인 측정이 이루어지지 못하였다. 이러한 이유에서 본 천문대에서는 2008년 5월부터 SBIG사의 시상 모니터를 도입, 매일 시간별 시상을 꾸준히 측정하고 있다. 시상 측정은 CCD로 직접 천체 이미지를 촬영하여 FWHM지수를 추정하는 방식으로 이루어진다. 우리는 지난 8개월 동안 시상 모니터를 운영하면서 얻어진 한국과학영재학교 천지인 천문대에서의 시상 자료를 바탕으로 KSA SEMO에서의 시상 패턴을 'Sunset/sunrise Effect', 'Extreme Fluctuation', 'Sudden Increment', 'Daily Variation', 'Stable Condition' 등으로 분류하였다. 시상은 전반적으로 오전 1시에서 3시까지가 다른 시간대에 비하여 좋은 것으로 나타났으며, 여름의 시상이 겨울보다 좋았다.
        4,000원