• Development and Reproduction
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• v.11 no.3
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• pp.167-177
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• 2007

In the present study, we isolated three human adult stem cells including adipose tissue-derived stem cells(HAD), umbilical cord-derived stem cells(HUC), and amnion-derived stem cells(HAM) and analysed their characteristics. And we examined whether HAD could be used as therapeutical cells for the heart diseases. Both HAM and HUC appeared very similar morphology but HAD was different. Doubling time of HUC was most fast, but total doubling numbers of HUC was same with HAM. Total doubling numbers of HAD was much more than others. Expression patterns of genes and proteins of three human adult stem cells were very similar. Also they were differentiated into adipocytes, osteocytes, and chondrocytes. In addition, they expressed many cardiomyocyte-related genes. But expression pattern of genes is a little different. When HAD were cultivated in the presence or absence of various combinations of BMP and FGF after 5-azacytidine expose for 24 h, expression of Cmlc-1, and ${\alpha}1c$ genes was significantly increased. However, expression of troponin T, troponin I and Kv4.3 genes was not changed. Based on these observations, it is suggested that HAD, HUC, and HAM might be used as potentially therapeutical cells for clinical application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.179-179
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• 2009

This is for the electrical characterization by IDC pattern using BST$(Ba_{0.5}Sr_{0.5}TiO_3)$ thin film. BST materials had been chosen for high frequency applications due to it's high permitivity and tunability. The BST thin films have been deposited on $Al_2O_3$ Substrates by Nd-YAG pulsed laser deposition with a 355nm wavelength at $700\;^{\circ}C$. The post deposition annealing at $750^{\circ}C$ in flowing $O_2$ atmosphere for 1 hours. The capacitance of IDC patterns have been measured from 1 to 10 GHz as a function of electric field ($\pm40$ KV/cm) at room temperature using inter-digital Au electrodes deposited on top of BST. The IDC patterns have three type of fingers number. For the 10 pairs finger was the best capacitance onto $Al_2O_3$ substrate. The capacitance was 0.9pF. Also Dielectric constant was been 351 at 100 mTorr and annealing temperature $750^{\circ}C$ for 1 hour. The loss tangent was been 0.00531.

• Journal of the Korean Ceramic Society
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• v.34 no.8
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• pp.877-885
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• 1997

The dependence of strength, crack growth, fracture mode and degree of domain rearrangement of PZT ceramics on poling strength were studied. The PZT [(Pb0.94Sr0.06)(Zr0.46Ti0.54)O3+Nb(trace)] specimens were poled at 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 kv/mm, and the strength of the specimens was measured by 3 point flexure system. The bending strength of the specimen decreased in different modes according to the bending directions; xz, zx and yz plane direction with x axis of the poling direction in Cartesian coordinate system. The strength differences between the directions increased as the poling strength increased. The fracture mode transferred to intergranular fracture mode from transgranular one as the poling strength increased. The mechanical breakdown occurred when the poling strength higher than 3 kV/mm was applied to the specimen. It was observed that the crack length increased in the normal direction to the poling direction, however, decreased in the parallel direction to the poling direction when the poled PZT specimen was indented by the Vickers indenter. However, the crack produced by indentation continuously was continuously increased little by little after indentation on the specimen. The domain rearrangement occurred as the poling strength increased and the domains were rearranged more effectively when the electric field was continuously increased little by little.

• Journal of Genetic Medicine
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• v.7 no.2
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• pp.133-137
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• 2010

Purpose: Beckwith-Wiedemann syndrome (BWS) is an overgrowth malformation syndrome caused by a methylation abnormality at chromosome 11p15, consisting of two imprinting centers, BWSIC1 (IGF2, H19) and BWSIC2 (LIT1, KvDMR). This study evaluated the applicability of a methylation-specific (MS) PCR RFLP method for the genetic diagnosis of BWS. Materials and Methods: A total of 12 patients were recruited based on clinical findings. Karyotyping was performed using peripheral blood leukocytes, and genomic DNA was treated with bisulfate and amplified using methylation-specific primers. RFLP was conducted with restriction enzymes in differentially methylated regions of LIT1, H19, and IGF2. Results: The 12 BWS patients had normal karyotypes. Abnormal methylation patterns in the BWSIC2 (LIT1) region were identified in seven patients (58.3%) using the MS-PCR RFLP method. Conclusions: The MS-PCR RFLP method is a simple, economical genetic test. It detected genetic abnormalities in 50-60% of BWS patients, suggesting that it can be used as a screening test. A more precise method is required, however, to enhance the detection rate of genetic abnormalities, especially in BWSIC1 region.

• Korean Journal of Computational Design and Engineering
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• v.18 no.2
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• pp.113-119
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• 2013

This paper proposes an approach to detect unintended deflections in an automotive outer panel. Conventionally, the detection of unintended deflections has been performed by experienced works, and it requires much amount of time and efforts. The motivation of this work is to reduce such efforts by providing an automated detection methodology. For the detection of unintended deflections, we make use of the measured data from an optical scanner which can be considered as a Z-map data. The proposed approach consists of four major steps; 1) measured data acquisition for an automotive outer panel, 2) identification of shape features, 3) removal of shape features, and 4) detection of unintended deflections via curvature analysis.

• 전기의세계
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• v.38 no.6
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• pp.12-18
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• 1989

한국형 고속전철을 고려하는데 있어서 위에서의 기술적인 측면보다도 오히려 수송용량, 경제성, 운영방식의 측면에서 더 많은 비중을 두고 검토해야 하는지도 모른다. 그러한 측면에서 한국형 고속전철은 한국의 지형조건, 경부간의 연변인구, 현경부선의 장래, 고속전철의 운영방식, 한국철도의 기술수준 등을 고려하지 않으면 안되고 한국형이어야 한다. 한국형 고속전철은 1. 경부간 고속전철의 거리는 380Km정도이므로 2000년대의 국민 일인당 시간가치를 기준으로 최고속도를 결정하여야 하고 표정속도는 190Km/h이상이어야 한다. 2. 고속화를 위한 필수조건인 차량의 축중을 17톤 이하로 제한하여야 하고 기존의 철도차량이 고속전철선에 야간열차등으로 투입되더라도 이 원칙은 유지되어야 한다. 3. 수송능력을 확보하기 위하여 열차편성당 좌석수는 800석 이하로 확보되어야 한다. 4. 기존선에서의 연장운행이 불가피하므로 기존선의 차량한계 내에서 안전하게 운행될 수 있어야 하고 전력공급은 기존선 방식인 A/C25KV, 60HZ의 사용이 불가피하다. 5. 고속전철의 건설비용, 차량의 제작비, 기술이전도, 국산화율 등을 고려한 시스템이어야 한다. 한국형 고속전철은 위의 기본원칙을 최소한 만조시킬 수 있는 시스템이어야 한다.

• Journal of the Korean Ceramic Society
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• v.22 no.1
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• pp.47-52
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• 1985

The effect of calcining temperature on planar coupling factor Kp resonance and antiresonance frequency of $Pb(Z_{0.53}Ti_{0.47})O_3$ doped with $Nb_2O_5$ has been investigated. The calcining temperature ranged from $700^{\circ}C$ to 110$0^{\circ}C$ The calcining temperature affected on antiresonance frequency more strongly than the resonance frequency. Therefore the Kp was almost entirely dependent upon the antiresonance frequency. The p and antiresonance frequency of the sample in creased with the calcining temperature reaching a maximum at about 90$0^{\circ}C$ When a poling electric field of 35KV/cm was applied to the sample calcined at 90$0^{\circ}C$ and sintered for two hours at 120$0^{\circ}C$ Kp attained a maximum value of 0.64 which is in good agreement with the results of other investigators.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.402-405
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• 2002

본 연구에서는 22.9KV 중전압 삼상 배전선로에 9KHz-30MHz의 주파수를 반송파신호로 인가하였을 때 나타나는 방사전계를 측정하였다. 중 전압 통신채널을 대지귀로방식으로 디지털신호를 인가하였을 때 3m와 10m법의 표준 방사전계 측정법을 적용하였다. 삼삼 배전선로에서 단일신호 보다 다중 신호전송에서 방사전력이 우수함이 나타내었으며 다중전송신호의 세기를 20㏈m로 하였을 때 1.8km까지 전송가능함을 확인하였고, 반송주파수 30MHz에 대하여 10m 측정법으로 방사전계를 측정하였더니 40㏈u/m임을 확인하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.110-113
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• 1992

This paper presents the results on experiments of relative dielectric constant dielectric loss, conductivity change and breakdown voltage of the L.D.P.E. mixed with Dodecyl Alcohol. The frequency range is 0.1 - 20 MHz and temperature, 20 - 80 $^{\circ}C$. Dielectric properties were similar to those of nonpolar polymers. Until $60^{\circ}C$ the conductivity value of compound was decreased with temperature increasment. And, its breakdown voltage was measured higher, about 3-4KV, than that of the pure L.D.P.E.. Also the amount of remnants of DA in the compounds were considered.

• 전기의세계
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• v.25 no.1
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• pp.64-66
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• 1976

고도의 경제성장과 각산업의 근대화로 전력수요는 날로 급증하고 있어 1961년 3사통합당시 발전소시설용량이 36만KW, 연간발전량이 19역KWH였음에 대하여 75년 현재 500만KW에 180억KWH를 육박하고 있어 실로 괄목할 만한 발전이라 아니할 수 없다. 뿐만 아니라 내년에는 345KV 초고압송전선로가 정상 가동될 것이며 단위용량 65만KW의 고리원자력발전소가 계통에 투입될 것이 예상되므로 한국의 전력계통도 명실공히 근대화되었다고 할 수 있겠다. 이와 같이 전력게통이 대규모복잡화됨에 따라 한층 더 고도의 전력기술이 요구되며 전기의 질적향상에 대한 사회적 요망도 날로 고조되고 있으므로 이에 대처하기 위해서는 무엇보다 우수한 기술자 확보와 연구기관의 질적향상이 시급하며 지금까지 선진국의 다양한 기술과 기기도입으로 항시 외국에 의존하여 해결해 왔으나 장차에는 국산화추진, 외자대체, 수출입국등 국가시책에 적극 호응해야 될 것이며 우리사회로서는 자체에서 사용빈도가 높은 기기부터 국내 메이커측과 공동개발을 적극 추진함으로서 전력기술의 발전과 아울러 외화절약에 공헌토록 진력하고 있다.