• 전기학회논문지
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• 제65권6호
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• pp.1083-1088
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• 2016

25.8kV GIS part generated by sensors to measure contact an inflow of noise depending on the extent of the measured discharge occurs often not easy. Partial discharge signal measurement sensor suitable for developing a more useful measurements at the scene to this, partial discharge waveform analysis developed a sensor, and to utilize forSensor on the development of the most important is VSWR decided to (voltage standing wave ratio) voltage standing-wave ratio less than 1.5 and decided less than at the full spectrum bands that are measured, this time Return loss, as measured value by absolute criteria 14.0 dB produced the sensor, designed to or more. UHF 1.5~0.5 GHz bandwidth spectrum to be measured in GIS. UHF bands were designed to be able to measure the best signal. Recently, 25.8kV GIS production company has been increasing variety of GIS were made open spacer in partial discharge in accordance with the not very easy to detect the signal. The sensor is designed height of four cm external spacer is attachment GIS in an influx of outside noise measurement, and be so manufactured as to facilitate the least we've done. Also, since partial discharge which occur can measure the frequency of the 170kV GIS external partial-discharge signals that occur at the scene of insulation applied to the spacer. Features, and also derived good results using global positioning. Also measured discharge point about sensors that are stable and the reliability of the development and local substation equipment failure occurring signal analysis through the discharge for the prevention of widely. There should be to believe that used.

• Asian-Australasian Journal of Animal Sciences
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• 제21권6호
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• pp.831-837
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• 2008

The objective of this study was to evaluate the effects of ruminally-protected methionine supplementation (0, 7, or 14 g/head/d) on nutrient intake, digestibility, growth performance, carcass, and meat characteristics of Awassi ram lambs fed finishing diets. Twenty four Awassi ram lambs ($16.8{\pm}1.17kg$ body weight) were randomly assigned to 3 treatment diets (8 lambs/treatment) and housed in individual pens. Lambs were given an adaptation period of 7 days before the intensive feeding period that lasted for 86 days. On day 74 of the trial, a digestibility experiment was performed. At the end of the trial (d 86), all lambs were slaughtered to evaluate carcass characteristics and meat quality. Increasing the level of methionine supplementation did not improve (p>0.05) performance nor feed conversion ratio. Nutrient intake and digestibilities were not influenced (p>0.05) by methionine supplementation. There were no differences in final weight, hot and cold carcass weights, dressing percentages or any of the measured non-carcass components. Tissues and fat depth measurements together with all meat quality attributes measured on longissimus muscle of the loin cut were not affected by methionine supplementation. The only meat quality parameters affected were redness (a*) and the hue angle being higher for the control group (p<0.05). These results suggest that methionine supplementation is not likely to produce any production benefits in nutrient digestibilities, performance or carcass characteristics of ram lambs fed a high performance diet.

• 한국항공우주학회지
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• 제34권4호
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• pp.70-75
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• 2006

액체로켓용 터보펌프의 설계과정에서 정확한 성능예측을 위해서 인듀서, 임펠러, 볼류트, 실 등의 펌프의 모든 부분을 포함한 유동해석을 수행하였다. 계산시간을 줄이기 위해서 인듀서와 임펠러는 주기조건을 사용하여 하나의 블레이드 통로만 해석하였으며, 인듀서와 임펠러, 임펠러와 볼류트 등의 상호작용은 정상적 해석법인 혼합면 기법을 사용하였다. 펌프의 모든 부분을 포함한 계산을 통하여 인듀서, 임펠러, 볼류트 등의 단독 유동해석을 통해서는 예측할 수 없는 펌프설계의 매우 중요한 부분인 축추력 등을 예측할 수 있었으며, 각 부품이 전체 성능에 미치는 영향을 자세히 파악할 수 있었다. 계산결과를 실험결과와 비교하였는데, 양정, 효율, 볼류트 외벽 압력분포 등에서 실험결과와 잘 일치하였다. 또한 실험으로 검증하지는 못하였지만, 축추력, 반경방향 힘 등의 예측값도 설계요구조건을 만족시키는 것으로 나타났다. 따라서 펌프의 전부분을 포함한 유동해석법은 터보펌프의 설계 및 성능예측에 매우 유용하게 적용될 수 있을 것으로 판단된다.

• 수산해양기술연구
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• 제36권1호
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• pp.1-11
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• 2000

A low frequency, high power hydroacoustic transducer with 7 tonpilz piston elements assembled in a circular array suitable for marine application, such as the transmission of underwater information and the development of new fisheries resources in the deep sea zone was designed. A modified Mason's model was applied to monitor and to simulate the transducer behavior at each step during the fabrication. The in air, and in water constructed tonpilz transducer was tested experimentally and numerically by changing the size and the type of the material for head, tail and acoustic window. Also, the developed transducer was excited by pulse signals and the received waveform was analyzed. The resonance peaks in the transmitting voltage response(TVR) of a single tonpilz element without housing were observed at 11.33kHz in air and 10.93kHz in air and 10.93 kHz in water, respectively, with the overall electrical-acoustic efficiency of 43.7%. The value of TVR of single tonpilz element with aluminum housing in water was 129.87dB re 1 $\mu$Pa/V at 12.25 kHz with the frequency bandwith of 2.15 kHz and half beam angle of 30.2$^{\circ}$at -3dB.The resonance peaks in the transmitting voltage response of the 7 element circular transducer were observed at 11.50 kHz in air and 11.45 kHz in water, respectively. The value of TVR in water 144.84 dB re 1$\mu$Pa/V at 11.5kHz with the frequency bandwith of 4.25 kHz and the half beam angle of $22.3^{\circ} $ at -3dB.Reasonable agreement between the experimental measurements and the theoretical predictions for the directivity patterns, TVRs and the impedance characteristics of the designed transducer was achieved.

• Archives of Plastic Surgery
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• 제39권4호
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• pp.338-344
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• 2012

Background It is known that nonsynostotic plagiocephaly does not spontaneously improve, and the craniofacial deformities that result from it. This study was conducted to analyze the effectiveness of helmet therapy for the nonsynostotic plagiocephaly patient, and to suggest a new treatment strategy based on this analysis. Methods A total of 108 pediatric patients who had undergone helmet therapy after being diagnosed with nonsynostotic plagiocephaly were included in this study. The patients were classified according to the initiation age of the helmet therapy, severity, and helmet wearing time. The treatment effect was compared using cranial vault asymmetry (CVA) and the cranial vault asymmetry index (CVAI), which were obtained from diagonal measurements before and after therapy. Results The discrepancy of CVA and CVAI of all the patients significantly decreased after helmet therapy. According to the initiation time of helmet therapy, the treatment effect was best at 5 months old or less. The helmet wearing time per day was proportional to the treatment effect up to 20 hours. In addition, the rate of the successful treatment (final CVA ${\leq}$ 5 mm) significantly decreased when the initiation age was 9.1 months or older and the treatment period was less than 7.83 months. Conclusions This study showed the effectiveness of the helmet therapy for nonsynostotic plagiocephaly patients. Based on analysis of this study, helmet therapy should be started at the age of 9 months or younger for 7.83 months or more, and the helmet wearing time should be more than 20 hours a day.

• 소음진동
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• 제7권2호
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• pp.231-238
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• 1997

진동하는 구조물의 평면 진동장을 측정하기 위해, 자동화된 스캐닝 레이저 도플러 진동 측정기를 개발하고 이의 성능을 시험하였다. 광섬유를 사용하여 레이저 탐침이 진동체 표면을 따라 움직일 수 있도록 하였으며, 시스템의 자동화를 이루기 위한 알고리즘을 고안하였다. 시스템의 자동화과정은, 레이저 탐침이 진동체 표면을 따라 움직이도록 하며, 표면의 각 측정 점마다 두 레이저 광선들의 초점을 맞추고, 진동 신호 데이터를 얻고 저장하는 모든 과정을 포함한다. 따라서 이 자동화 과정을 이용하여 구조물의 표면 진동장을 측정할 수 있도록 하였다. 이 진동 측정기의 성능을 시험하기 위하여, 연속신호로 가진되는 압전 원통 셸의 진동과 펄스 신호에 의해 가진되는 평판의 진동을 측정하였다. 측정결과로부터, 구조물의 평면 진동장을 측정하고 표면을 따라 전파되는 탄성파들을 분리해내기 위하여, 이 자동화된 스캐닝 레이저 도플러 진동 측정기가 유용한 측정 도구가 될 수 있음을 보였다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.363-367
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• 2003

우라늄 산화물의 금속전환을 위해 고온 용융염 중에서 전기화학적 환원공정에 대한 관심이 고조되고 있다. 본 공정은 우라늄 산화물뿐만 아니라 다른 악틴족 원소 산화물 및 일부 희토류원소 산화물 역시 금속으로 환원되는 장점을 가지고 있다. 이러한 금속산화물들은 독창적으로 고안된 일체형 음극 및 불활성 양극을 이용하여 금속으로 환원되며, 음극에서 발생된 산소 이온은 양극으로 전달되어 산화됨으로서 산소기체를 발생시킨다. 용융염 중에서 알칼리 및 알칼리토류 산화물에 대한 전기화학적 거동은 아직 완전히 밝혀지지 않았으며, 후행핵연료주기의 단위공정으로서 개발중에 있다. 사용후핵연료의 열 부하는 주로 세슘 및 스트론슘에 의한 것으로, LiC1 용융염 중에서 세슘, 스트론슘 및 바륨 산화물에 대한 용해 속도 및 환원전위를 고찰하였다.

• 한국산학기술학회논문지
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• 제16권4호
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• pp.2744-2748
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• 2015

본 논문에서는 전자정부 표준 프레임워크 프로젝트 내에서 MDD/MDA 기술 적용으로 인한 생산성과 품질 향상효과를 기능점수 (Function Point) 관점과 코드 인스펙션 관점에서 분석하여 제시한다. 또한 본 사례의 프로젝트에서 적용한 MDD/MDA적용 방법을 소개한다. MDD 기법의 발전과 더불어 그 효과를 검증하기 위해 다양한 연구가 진행되고 있으나, 대부분은 사례 연구를 통해 얻어지는 교훈이나, 제한된 측정 데이터로 분석된 효과를 제시하고 있다. 본 연구에서는 효율적인 개발 방법론과 전자정부 표준 프레임워크를 활용하여 MDD를 실제 정보시스템 개발 프로세스에 적용한 사례 연구를 통해 새로운 측정지표로 정량적 효과성을 측정하였다. 더불어 Application Life-Cycle 환경에서 모델링 된 정보들을 통합 저장소를 통하여 관리함으로써 추적성과 가시성이 확보된 방안을 제시한다.

• Imaging Science in Dentistry
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• 제38권1호
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• pp.7-15
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• 2008

Purpose: This study provides comparative measurements of absorbed and effective doses for newly developed cone beam computed tomography (CT) in comparison with these doses for conventional CT. Materials and Methods: Thermoluminescent dosimeter rods (TLD rod: GR-200, Thermo Fisher Scientific Inc., Waltham, MA, USA) were placed at 25 sites throughout the layers of Male ART Head and Neck Phantom (Radiology Support Devices Inc., Long Beach, USA) for dosimetry. Implagraphy, DCT Pro (Vatech Co., Hwasung, Korea) units, SCT-6800TXL (Shimadzu Corp., Kyoto, Japan), and Crane x 3+(Soredex Orion Corp., Helsinki, Finland) were used for radiation exposures. Absorption doses were measured with Harshaw 3500TLD reader (Thermo Fisher Scientific Inc., Waltham, MA, USA). Radiation weighted doses and effective doses were measured and calculated by 2005 ICRP tissue weighting factors. Results: Absorbed doses in Rt. submandibular gland were 110.57 mGy for SCT 6800TXL (Implant), 24.56 mGy for SCT 6800TXL (3D), 22.39 mGy for Implagraphy 3, 7.19 mGy for DCT Pro, 5.96 mGy for Implagraphy 1, 0.70 mGy for Cranex 3+. Effective doses $(E_{2005draft)$ were 2.551 mSv for SCT 6800TXL (Implant), 1.272 mSv for SCT 6800TXL (3D), 0.598 mSv for Implagraphy 3, 0.428 mSv for DCT Pro and 0.146 mSv for Implagraphy 1. These are 108.6, 54.1, 25.5, 18.2 and 6.2 times greater than panoramic examination (Cranex 3+) doses (0.023mSv). Conclusion: Cone beam CT machines recently developed in Korea, showed lower effective doses than conventional CT. Cone beam CT provides a lower dose and cost alternative to conventional CT, promising to revolutionize the practice of oral and maxillofacial radiology.

• Bulletin of the Korean Chemical Society
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• 제29권4호
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• pp.799-804
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• 2008

An amphiphilic diacetylene compound was deposited on the surface of nano sized magnetite particles ($Fe_3O_4$) using a self-assembly method. The diacetylene molecular assembly formed on the surface of nanoparticle was subjected to photopolymerization. This resulted in the formation of a polymeric assembly on the surface of the nanoparticles in which the adjacent diacetylene molecules were connected through conjugated covalent networks. The presence of immobilized polymer species on the surface of nanoparticles is expected to protect them from agglomeration and ripening, thereby stabilizing their physical properties. In this work, $Fe_3O_4$ nanoparticles were prepared by chemical coprecipitation method and the diacetylene molecule 10,12- pentacosadiynoic acid (PCDA) was anchored to the surface of $Fe_3O_4$ nanoparticles through its carboxylate head group. Irradiation of UV light on the nanoparticles containing immobilized diacetylenes resulted in the formation of a polymeric assembly. Presence of diacetylene molecules on the surface of nanoparticles was confirmed by X-ray photoelectron spectroscopy and FT-IR measurements. Photopolymerization of the diacetylene assembly was detected by UV-Visible spectroscopy. Magnetic properties of the nanoparticles coated with polymeric assembly were investigated with SQUID and magnetic hysteresis showed superparamagnetic behaviors. The results put forward a simple and effective method for achieving polymer coating on the surface of magnetic nanoparticle.