• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.114-115
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• 2007

In this study, low temperature sintering property of the $0.6TiTe_3O_8-0.4MgTiO_3$ ceramics with sintering adds were investigated for LTCC application which enable to cofiring with Ag electrode. $TiTe_3O_8$ mixed with $MgTiO_3$ to improve the temperature property. In the X-ray diffraction patterns, the columbite structure of $TiTe_3O_3$ phase and ilmenite structure of $MgTiO_3$ phase were coexisted in all specimens. In the case of $H_3BO_3$ addition, the bulk density and dielectric constant were decreased but quality factor was increased with amount of $H_3BO_3$ additions. The TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3+xwt%H_3BO_3$ ceramics were moved to positive direction. In another case, SnO addition, the bulk density and dielectric constant were increased but Quality factor was decreased with amount of SnO additions. The TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3$+ywt%SnO ceramics were shifted to negative direction. The dielectric constant, quality factor and TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3$ ceramics with $2wt%H_3BO_3$ and 2.5wt%SnO sintered at $830^{\circ}C$ for 1h, were 28.5, 39,570GHz, $+9.34ppm/^{\circ}C$ and 29.86, 35,80000z, $-0.58ppm/^{\circ}C$, respectively.

• 한국결정성장학회지
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• 제14권2호
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• pp.50-57
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• 2004

Mercurous Bromide ($Hg_2Br_2$) crystals hold promise for many acousto-optic and opto-electronic applications. This material is prepared in closed ampoules by the physical vapor transport (PVT) growth method. We investigate the effects of solutal convection on the crystal growth rate in a horizontal configuration for diffusive-convection conditions and purely diffusion conditions achievable in a low gravity environment. Our results show that the growth rate is decreased by a factor of one-fourth with a ten reduction of gravitational acceleration near y = 2.0 cm. For 0.1 $g_O$ the growth rate pattern exhibits relatively flat which is intimately related to diffusion-dominated processes. The growth rate nonuniformity is regardless of aspect ratio across the interfacial positions from 0 to 1.5. Also, the effect of a factor of the ten reduction in the gravitational acceleration is same to both Ar = 5 and 2. The enlargement in the molecular weight of B from 50 to 500 by a factor 4 causes a decrease in the maximum growth rate by the same factor, indicative of the effect of solutal gradients.

• 한국전기전자재료학회논문지
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• 제21권11호
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• pp.1000-1004
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• 2008

In this paper, the influences of poling electric field on piezoelectric properties of $0.95(K_{0.5}Na_{0.5})NbO_3$-$0.05Li(Sb_{0.8}Nb_{0.2})O_3$ (abbreviated as KNN-LSN) ceramics were investigated. The specimens was sintered at sintering temperature of $1050^{\circ}C$. They showed orthorhombic phase structure without secondary phase. Electromechanical coupling factor (kp), dielectric and piezoelectric constant($d_{33}$) increased with poling electric field. However, mechanical quality factor (Qm) decreased. Take into account of poling conditions and piezoelectric properties of KNN-LSN ceramics, the optimum poling condition for KNN-LSN ceramics was poling electric field of 4.5 kV/mm. At the time, kp of 0.458, Qm of 43.97, $d_{33}$ of 278 pC/N, and dielectric constant of 1079 were shown, respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.147-150
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• 2002

HPSL(High Pressure Sodium lamp)have attracted much attention in recent years, because they offer high luminous efficiency and very long life. Recently, AC-DC converters have been widely as power factor improvement circuits in the power conversion equipment An application of the ZVT-PWM(Zero Voltage Transition Pulse Width Modulation) boost converter, which has great advantage on miniaturization and high power density, to the power factor improvement circuit of the HPSL inverter are described to identify the power factor correction characteristics of the inverter. In this paper the series-parallel resonant inverter(electronic ballast) for driving a HPS lamp is discussed. Finally, a power factor corrector is cascaded in front of the electronic ballast. Consequently, a high power factor above 0.99 and low THD on the line current can be achieved.

• 정신신체의학
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• 제15권2호
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• pp.88-92
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• 2007

연구목적 : 한국판 텔레겐몰입척도(the Korean Version of Tellegen Absorption Scale ; 이하 TAS-K)는 몰입 경험을 표현한 자기-기술식 설문 척도로서 최면감수성을 반영하는 것으로 알려져 있다. 본 연구에서는 TAS-K의 내적 신뢰도를 포함하여 그 요인구조를 알아보고자 하였다. 방법 : 서울 소재 일 대학교의 학생 139명을 대상으로 TAS-K를 사용하여 설문조사를 시행하였다. 척도의 신뢰도 계산을 위해 내적 일관성 지수인 Cronbach's alpha를 산출하였으며 구성 타당도를 검증하기 위해 요인분석을 실시하였다. 결과 : TAS-K의 Cronbach's $\alpha$의 값이 0.82로 나타나 척도의 내적 신뢰도가 비교적 높은 것으로 나타났다. 요인분석을 실시한 결과에서는 고유치 1.0 이상의 요인들을 추출했을 때 3개의 하위요인이 추출되었는데, 1요인은 일시적인 유사 해리 경험, 2요인은 상상적 몰두, 3 요인은 지각적 민감성 등을 각각 반영하고 있었으며, 총 분산의 31.06%를 설명하였다. 결론 : TAS-K는 비교적 내적 신뢰도가 높았으며, 하위요인은 최면감수성과 관련된 특성들을 반영하고 있었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권1호
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• pp.3-10
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• 2014

Objectives: Although nerve growth factor (NGF) could promote the functional regeneration of an injured peripheral nerve, it is very difficult for NGF to sustain the therapeutic dose in the defect due to its short half-life. In this study, we loaded the NGF-bound heparin-conjugated fibrin (HCF) gel in the NGF-delivering implants and analyzed the time-dependent release of NGF and its bioactivity to evaluate the clinical effectiveness. Materials and Methods: NGF solution was made of 1.0 mg of NGF and 1.0 mL of phosphate buffered saline (PBS). Experimental group A consisted of three implants, in which $0.25{\mu}L$ of NGF solution, $0.75{\mu}L$ of HCF, $1.0{\mu}L$ of fibrinogen and $2.0{\mu}L$ of thrombin was injected via apex hole with micropipette and gelated, were put into the centrifuge tube. Three implants of experimental group B were prepared with the mixture of $0.5{\mu}L$ of NGF solution, $0.5{\mu}L$ HCF, $1.0{\mu}L$ of fibrinogen and $2.0{\mu}L$ of thrombin. These six centrifuge tubes were filled with 1.0 mL of PBS and stirred in the water-filled beaker at 50 rpm. At 1, 3, 5, 7, 10, and 14 days, 1.0 mL of solution in each tubes was collected and preserved at $-20^{\circ}C$ with adding same amount of fresh PBS. Enzyme-linked immunosorbent assay (ELISA) was done to determine in vitro release profile of NGF and its bioactivity was evaluated with neural differentiation of pheochromocytoma (PC12) cells. Results: The average concentration of released NGF in the group A and B increased for the first 5 days and then gradually decreased. Almost all of NGF was released during 10 days. Released NGF from two groups could promote neural differentiation and neurite outgrowth of PC12 cells and these bioactivity was maintained over 14 days. Conclusion: Controlled release system using NGF-HCF gel via NGF-delivering implant could be an another vehicle of delivering NGF to promote the nerve regeneration of dental implant related nerve damage.

• 한국토양비료학회지
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• 제35권2호
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• pp.87-92
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• 2002

북한 지역은 산이 많고, 경사지 밭이 많아 토양 유실이 심하므로, 토지를 보호하는 것이 토양의 지력 유지에 중요하다. 토양 보전 대책 마련을 위해서는 각 지역의 토양 유실 가능량을 예측하는 것이 필요하다. 토양 유실 예측에 USLE가 광범위하게 적용된다. 북한 지역의 토양 유실 예측에 필요한 강수 인자8의 산출이 시도되었다. 북한 지역의 수집 가능한 75개소의 월 강수량 자료를 이용하였다. 월 강수량의 7, 8월 강수 집중도(X)로부터 지역 보정 인자를 산출하였다. 지역 보정 인자($U_{adj}$) 산출을 위한 기본식은 남한의 중북부 지역 20개소의 $EI_{30}$와 월강수량 자료로부터 얻어 낸 식 $$U_{adj}=4.095{\cdot}X-0.878(r=0.689^{**})$$ 을 적용하였다. 북한 지역의 강수량은 606-1,520mm이었으며, 7, 8월 집중도는 34.4%~53.8%이었다. 이에 따른 지역 보정 계수 $U_{adj}$는 0.53~1.33이었으며, 동해안과 산간 지방의 $U_{adj}$ 값이 서해안과 내륙 지방의 $U_{adj}$ 값보다 낮았다. 지역 보정 계수를 고려한 USLE의 강수 인자 $R_{adj}$는 107 ~ 493으로 평가되었으며, 이는 평균 259.6으로 남한의 평균 R 값 434.5보다 낮았다.

• Journal of Nutrition and Health
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• 제45권4호
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• pp.390-399
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• 2012

The objective of this study was to develop and evaluate the construct validity of a Nutrition Quotient (NQ) for children. In a previous report (Kang, et al., 2012), the food behavior checklist for children's NQ, consisting of 19 items, was grouped into a 5-factor structure according to the exploratory factor analysis: balance, diversity, moderation, regularity, and practice. In this study, the construct validity of the NQ was assessed using a confirmatory factor analysis. Elementary school students (n = 1,393) from six large cities completed the NQ test. Indicator tests suggested an adequate model fit (goodness of fit index = 0.9613; adjusted GFI = 0.95; standardized root mean square residual = 0.0464; chi-square test statistics of < 0.001 p-value, 82.1), and item loadings were significant for all subscales (p < 0.05). The standardized path coefficients were used as the weights of the items. The NQ and the 5 factor scores of the student were calculated by the obtained weights of the questionnaire items. Logistic regression was applied to find the significant factors in order to affect a specific nutrient status. The receiver operation characteristic curve analyses were performed in order to find diagnostic cut-off points of the five factors. The food behavior checklist for children's NQ would be a handy and suitable instrument for evaluating dietary behaviors of Korean children.

• 생명과학회지
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• 제22권11호
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• pp.1444-1450
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• 2012

본 연구의 목적은 1회성 축구활동이 남자 청소년의 혈청 뉴로트로핀 수준과 신경인지 기능에 미치는 영향을 규명하는데 있다. 연구의 대상은 건강한 남자 청소년 15명으로 하였으며, 연구 대상은 축구활동 처치(SOC) 조건과 자율학습 처치(CON) 조건의 2가지 처치 조건에 참여하였다. 채혈은 처치 전(Pre), 처치 후(Post), 처치 후 2시간(Post-2 h) 시점에서 총 3회 실시하였으며, 채취된 혈액을 이용하여 혈청 serum brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), insulin-like growth factor-1 (IGF-1)을 분석하였다. 신경인지 기능의 평가는 Stroop 색체-단어 검사를 이용하였으며, 채혈 시점과 동일한 시점에서 측정하였다. 연구 결과, 혈청 BDNF, NGF, IGF-1 수준은 축구활동 후 유의하게 증가하였으며(p<0.05), Post 시점에서 SOC 조건이 CON 조건과 비교하여 유의하게 높게 나타났다(p<0.05). Stroop 색체-단어 검사는 색체-단어 검사 점수에서 축구활동 후 유의한 증가를 나타내었으며(p<0.05), Post 시점과 Post-2 h 시점에서 SOC 조건이 CON 조건과 비교하여 유의하게 높게 나타났다(p<0.05). 이상의 결과를 종합하면, 1회성 축구활동이 뉴로트로핀을 증가시켜 신경인지 기능에 긍정적 영향을 나타낸 것으로 판단된다.

• 대한지역사회영양학회지
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• 제25권4호
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• pp.267-279
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• 2020

Objectives: This study investigated the utilization and satisfaction of lunchbox by considering the dietary lifestyle of the consumer, in order to refine the purchasing behavior of adults with experience in using lunchboxes, and to provide basic data for efficient menu configuration and direction towards improvement. Methods: A total of 600 adults in Seoul and Gyeonggi-do answered a self-administered questionnaire designed to investigate general characteristics, utilization, menu preference, satisfaction, prospection, and improvement of lunchbox, according to the dietary lifestyle. Results: The study subjects were classified into 5 groups: 'taste seeking group', 'safety seeking group', 'health seeking group', 'economic seeking group' and 'convenience seeking group. Considering purchase value of the lunchbox, the 'taste seeking group' had a high utilization rate (35.1%) for prices less than 4,000 won (P < 0.05). Lunchboxes were mainly purchased at the lunchbox store (43.3%) and convenience store (37.7%). The important factor that contributed to purchasing a lunchbox was taste (61.3%), which was highest in the 'taste seeking group' (P < 0.01). The 'health seeking group' showed the highest preference for the low-salt diet lunchbox menu (26.0%) (P < 0.05). The satisfaction of 'health seeking groups' was lowest when considering addition of condiments (2.34%), origin of ingredient (2.59%), and provided calorie (2.81%) (P < 0.05). The overall response indicated future use of the lunchbox (69.6%) (P < 0.01); 35.8% respondents recommended the purchase of lunchbox, where convenience of purchase was the highest factor contributing to recommendation (50.2%) (P < 0.05). Conclusions: Taken together, our results indicate that taste was emphasized in every group purchasing the lunch box. Convenience of purchase was the highest factor contributing to satisfaction, which was relatively low when considering addition of condiments, nutrition and origin of ingredients. We propose that it is necessary to improve the development of various menus for increasing satisfaction by selecting the right ingredients contributing to good health of the consumer.