• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.487-494
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• 2009

Friction coefficients of the prestressing tendon are the basic information required to control the prestressing force introduced to PSC structure during jacking. However, the friction coefficients show considerable differences depending on the specifications, causing much confusion to designers. In this study, the ranges of the friction coefficients presented in domestic and foreign specifications are compared together to clarify the differences. Then, a procedure is proposed that can be used to estimate the wobble and curvature friction coefficients from field data such as elongation and prestressing force and from theory related to the friction. The procedure is applied to various tendon profiles of several PSC bridges constructed by ILM, FCM and MSS. The resulting values are compared with those presented in some specifications and assumed in jacking and a reasonable range of the friction coefficient is discussed. Lift-off tests are also performed in some bridges to further verify the results. The resulting wobble friction coefficients are not as small as those presented in AASHTO specifications but range from the lower limit to mid point of domestic specifications, while the curvature friction coefficients approach or slightly exceed the upper limit.

• Monthly Korean Chicken
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• s.148
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• pp.86-89
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• 2007

본고는 지난 8월 일본식조협회로부터 받은 일본 계육산업의 전반에 대한 자료를 번역 정리한 것으로 우리나라의 계육업계에서도 참고할 내용이 있다고 보여진다. 내용 중 엔환율은 일본 엔화 100엔당 한화 800원으로 환산해 바로 볼 수 있도록 표를 편집한 것이다. 아울러 개념적으로 조금은 다른 부분들이 있어(예를 들면 출하 중량 : 일본의 출하 중량 1.7Kg KFC 출하를 위한 부분출하 후 생계중량 3.0Kg까지 사육 : 정육 유통 개념) 이를 감안하여 자료를 보아야 한다는 점이다. 이러한 자료를 통해 구체적인 일본의 계육산업을 돌아보고 파상적인 일본 시장이 아닌 실체적인 일본 시장에 보다 접근하는 계기가 되었으면 한다. 아울러 본 자료에는 유통 시장에 대한 내용이 보다 많이 소개되어 있다. 유통을 한번쯤 되돌아 볼 수 있는 기회가 되길 바란다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.16-19
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• 2001

접지된 유전체위에 스트립 격자에 대해 파가 비스비스듬하게 도파할 경우에 비교적 평탄한 Helix 구조로 볼수 있으며 이때 누설파 안테나 관점에서 복소전파상수와 복사패턴을 구하는 방법을 제시하였다. 그리고 유전체 두께가 매우 얇은 경우와 비교적 두꺼운 경우에 대하여 유전체 내부에서 파가 스트립 격자를 가로 질러 도파하거나 비스듬하게 도파하는 경우에 복소전 파상수와 복사패턴을 수치 계산하여 비교 고찰하였다.

• 동물약계
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• no.77
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• pp.3-4
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• 2001

[ $\cdot$ ]협회 제3차 이사회 개최 $\cdot$동물약사감시 행정처분 결과 홍보 $\cdot$생물학적제제 수급 협의회 개최 $\cdot$이산화염소제제 관련 협의회 개최 $\cdot$병역특례 지정업체 신청 안내 $\cdot$염산 옥시테트라싸이클린 알선 오파상 선정 $\cdot$2001년도 하반기 알찬 거래선 선정 $\cdot$동물 무료 진료활동 약품지원 $\cdot$제2차 OIE 동아시아 구제역 방역대책회의 $\cdot$'2001 한국 국제 애완동물 및 용품 박람회' 참가 안내

• Tribology and Lubricants
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• v.28 no.1
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• pp.12-18
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• 2012

This application study of a swash-plate type axial piston pump was concerned about the lubrication characteristics between cylinder barrel and valve plate which are the main rotating body and its opposite sliding part respectively. A computer simulation was implemented to assess bearing and sealing functions of the fluid film between cylinder barrel and valve plate. A numerical algorithm was developed to facilitate simultaneous calculations of dynamic cylinder pressure, 3 degree-of-freedom barrel motions considering inertia effect, and fluid film pressure assuming full fluid film lubrication regime. Central clearance, tilt angle, and azimuth angle of the rotating body were calculated for each time step. Surface waviness was found to be an influential factor due to the small fluid film thickness which can appear in flat land bearings. Five surface lays which can form on the lubrication surface in accordance with machining process were defined and analyzed using the simulation tool. Oil leakage flow and frictional torque in the fluid film between cylinder barrel and valve plate were also calculated to discuss in the viewpoint of energy loss. The simulation results showed that in actual sliding conditions proper surface non-flatness can make a positive effect on the energy efficiency and reliability of the thrust bearing.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.53-57
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• 1999

The experiments were conducted to determine the factors such as light and darkness, phytohormone and seed coat, influencing on seed germination of Bidens tripartita L. and B. frondosa. The seeds of both species were germinated when seed coat was damaged and weakened. $GA_3$ and BA stimulated germination of both species but ABA and IAA had no effect on germination of them, which ranged 50.0% to 80.0%. In B. forndosa, when inner layer of seed coat was removed, germination was highly promoted up to 96.7% compared with 10.0% germination rate in another treatments.

• Journal of the Korean Society for Nondestructive Testing
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• v.16 no.3
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• pp.184-191
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• 1996

The purpose of this paper is to investigate components of surface roughness in turning with respect to the tool configuration and the changes of working conditions. Tool configurations of SNMG120404, SNMG120408 and DNMG150404, DNMG150408 are used, and working conditions such as cutting speed 3nd feed are varied. That is, the changes of cutting speed and feed were 150, 200, 250 m/min and 0.05, 0.1, 0.3 mm/rev, respectively. From the results obtained by the frequency analysis with spectrum, it is noted that the surface roughness was influenced most significantly by the feed. It is also observed that the vibration of bite had an effect on both the surface roughness and the surface waviness. Moreover, the influence of surface roughness increases as the feed decreases. Lastly, the vibration of the spindle was found to have little influence on the surface roughness in normal cases and the tool configuration was not the components of the surface roughness.

• Korean Journal of Ichthyology
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• v.35 no.4
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• pp.244-252
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• 2023

This study compared the morphological and molecular characteristics of the two Pampus spp. in Korea, Japan and China to clarify the long-confused taxonomic status of the two Korean pomfrets named as "Byeong-eo" and "Deok-dae". Among them "Byeong-eo" was identified as Pampus punctatissimus in having the following morphological traits: patch of wavy ridges extending beyond the anterior tip of the pectoral fin, the groove on the lower ridge of gill cover absent, and the number of vertebrae 34. On the other hand, "Deok-dae" was identified as Pampus argenteus in having the following morphological traits: patch of wavy ridges not reaching to the anterior tip of the pectoral fin, the groove on the lower ridge of gill cover reaching to the lower jaw, and the number of vertebrae 38~42. In addition, "Byeong-eo" almost corresponded to P. punctatissimus from Japan in the mitochondrial DNA cytochrome c oxidase subunit I sequences (genetic distance=0.1%), while "Deokdae" showed genetic distance of 0.3% when compared to P. argenteus from China. Our comprehensive results suggest the validify of P. punctatissimus for "Byeong-eo", and P. argenteus for "Deok-dae".

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06c
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• pp.229-234
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• 1994

본 논문에서는 한국어 변이음을 인식하기 위한 시간지연 신경망의 확장 방법을 살펴보고 한국어 파열음의 벼이음을 인식하는 실험을 통해 각 확장 방법의 인식 성능을 비교한다. 먼저 변이음을 연속음성인식의 인식단위로 사용하기 위하여 한 음소이모든 변이음을 고려하면서 서로 유사한 변이음을 통합 분류하여 3개의 변이음 군으로 나눈다. 한국어 파열음에 대한 인식 실험결과, 음향 음성학적인 특성에 따라 나누어진 trbah 시간지연 신경망들을 모듈 별로 학습한 후, 계층적으로 통합하여 전체적인 시간지연 신경망을 구성하는 방법이 가장 좋은 성능을 나타내었다. 또한, 변이음 단위 인식이 음소 단위 인식에서 문제가 되는 조음 결합 현상을 해결할 수 있음을 확인하였고, 변이음 인식의 결과인 변이음 열이 제공하는 부가적인 정보를 음운파상에 이용하는 방법에 대해 고찰하였다.

• Journal of KSNVE
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• v.7 no.6
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• pp.953-958
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• 1997

Corrugation of railway track can be caused by the various dynamic behaviors of traveling wheels and track. In this paper, the coupled vibrations of traveling wheel and railway track are analyzed as the cause of corrugations. To analyze the coupled vibration, the track supported by the sleepers and the traveling wheels are identified to the elastically supported infinite beam and the spring-mass system which runs at constant speed. The Hertzian contact spring is considered between the infinite beam and spring-mass system are calculated. The cause and development of rail corrugation are discussed in the view point of contact force fluctuation affected by the elastic supports and the corrugated surface profile on the track. By the obtained results, the possibilities of resonance are checked between the excitation by the corrugated surface profile and the natural frequency of contact spring-mass system. It may be thought to a development of railway corrugation.