• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.198-203
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• 2007

본 연구의 목표는 air core의 길이 조절이 가능한 스월인젝터의 음향학적인 감쇠기능을 통해 고주파 연소불안정을 억제하는 것이다. air core(길이, 형상, 부피)와 인젝터의 위치에 대한 음향학적인 감쇠 효과는 선행 연구를 통해 실험되었다. 이러한 결과들을 바탕으로 다중 인젝터들의 효과에 대한 연구를 진행하였다. 실험 결과로부터 각 모드의 배(anti-node)에 장착된 인젝터들의 수의 증가로 감쇠효과가 증가하는 것을 확인하였다. 또한 각 모드들의 배(anti-node)에 장착되어 동조된 인젝터들이 동시에 개별적인 모드 감쇠 성능을 보일 수 있음을 확인했다.

• 미생물학회지
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• 제29권4호
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• pp.221-225
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• 1991

The RNA transcripts produced from in vitro transcription reaction of BTV core were analyzed on agarose-urea gel. Fast migrating abortive RNAs, in addition to full length species of RNA, were observed. Fast migrating RNAs extracted from agarose-urea gel were hybridized to all 10 segments of genomic ds RNA, while solw migrating RNAs extracted from agarose-urea gel were hybridized only to the large and medium size genomic ds RNA. These results indicate that fast migrating RNA transcripts are most likely the products of abortive transcription.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.178-178
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• 2008

This paper presents an efficient approach for simulating the loss of the laminated core joints in power transformers. Two laminated core models, with the same material and joint type but different leg length, are established for validating the specific total loss inside the joint region.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.1073-1077
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• 1996

This paper presents a recoil and counter recoil(R&CR) motion measurement method using linear variable differential transformers(LVDT). The output of a LVDT is obtained from the differential voltage of the 2nd transformers. As a sensor core is attached at the motion body, the output is directly proportional to the core motion. Displacement, velocity and acceleration are measure from the core length. With a comparison between the measurement result and the known value which is obtained by the precision steel tape, the accuracy and the usefulness of the proposed scheme is validated.

• 지구물리와물리탐사
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• 제14권4호
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• pp.305-315
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• 2011

암석시료에 대한 음파 속도측정의 정확성을 검증하고 정밀한 측정을 위한 기초적인 실험의 일환으로 아크릴과 스테인리스강 재질의 시료에 대하여 길이와 축하중을 달리하여 각각에 대해 3회씩 측정한 총 864 경우에 대하여, 시험편을 통과한 초동 주시를 측정하고 분석하였다. 축하중이 가해진 상태에서의 S-파 측정은 P-파에 비해 측정에 어려움이 있었으며 이에 따라 반복측정, 길이, 축하중에 의한 편차도 S-파가 훨씬 크게 나타났다. 또한, 재질에 따라서는 스테인레스강 시편보다는 아크릴 시편의 초동주시 편차가 약 2배 정도 양호하게 나타났으며 이는 아크릴 시험편의 경우가 트랜스 듀서와 시험편 간의 접촉 coupling이 안정적이며 또한 동일한 시간 분해능이나 유사한 전기적 잡음에 비하여 초동 주시가 길기 때문으로 판단된다. 실험결과, 아크릴 시험편과 스테인리스강 시험편의 탄성파 속도를 측정할 때는 60 ~ 90 mm 정도의 길이를 갖는 시험편을 20 kg (27.7 $N/cm^2$) ~ 30 kg (41.6 $N/cm^2$) 내외의 축하중 하에서 측정하는 것이 가장 좋으며, 스테인리스강 시험편의 S-파 속도는 길이 50 mm 이하의 시험편을 사용하여 측정해야 한다. 이러한 실험 결과는 암석 코어의 속도 측정시 시스템 지연의 측정 및 보정에 활용될 수 있을 것이다.

• Structural Engineering and Mechanics
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• 제66권6호
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• pp.783-792
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• 2018

This paper presents a detailed theoretical study of the sleeved compression members based on a mechanical model. In the mechanical model, the core protrusion above sleeve and the contact force between the core and sleeve are specially taken into account. Via the theoretical analyses, load-displacement relationships of the sleeved compression members are obtained and verified by the experimental results. On the basis of the core moment distribution changing with the increase of the applied axial load, failure mechanism of the sleeved compression members is assumed and proved to be consistent with the experimental results in terms of the failure modes and the ultimate bearing capacities. A parametric study is conducted to quantify how essential factors including the core protrusion length above sleeve, stiffness ratio of the core to sleeve, core slenderness ratio and gap between the core and sleeve affect the mechanical behaviors of the sleeved compression members, and it is concluded that the constrained effect of the sleeve is overestimated neglecting the core protrusion; the improvement of ultimate bearing capacity for the sleeved compression member is considered to be decreasing with the decrease of the core slenderness ratio and for the sleeved compression member with core of small slenderness ratio, small gap and small stiffness ratio are preferred to obtain larger ultimate bearing capacity and stiffness.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 춘계학술발표회논문집(1)
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• pp.19-26
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• 1998

Nuclear design bases for System-Integrated Modular Advanced ReacTor(SMART) core are presented. Based on the proposed design bases, a SMART core loading pattern is constructed and its nuclear characteristics are studied. The proposed core loading pattern satisfies 3-year cycle length and soluble boron-free operation requirements at any time during the cycle

• Computers and Concrete
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• 제27권4호
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• pp.369-383
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• 2021

This article deals with the frequency analysis of viscoelastic sandwich disk with graphene nano-platelets (GPLs) reinforced viscoelastic concrete (GPLRVC) face sheets and honeycomb core. The honeycomb core is made of aluminum due to its low weight and high stiffness. The rule of the mixture and modified Halpin-Tsai model are engaged to provide the effective material constant of the concrete. By employing Hamilton's principle, the governing equations of the structure are derived and solved with the aid of the Generalize Differential Quadrature Method (GDQM). In this paper, viscoelastic properties are modeled according to Kelvin-Voigt viscoelasticity. The deflection as the function of time can be solved by the fourth-order Runge-Kutta numerical method. Afterward, a parametric study is carried out to investigate the effects of the outer to inner radius ratio, hexagonal core angle, thickness to length ratio of the concrete, the weight fraction of GPLs into concrete, and the thickness of honeycomb core to inner radius ratio on the frequency of the viscoelastic sandwich disk with honeycomb core and FG-GPLRVC face sheet.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2009년도 정기 학술대회
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• pp.561-566
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• 2009

The outrigger system with a core is widely used for lateral load resisting system of tall building. Recently, structural systems in tall building are adopted to eccentric core and offset outrigger or one-armed outrigger system by trends in planning buildings of irregular type. Therefore, the performance of outrigger system with eccentric core in tall building is evaluated by 50-stories examples which are analyzed for variables such as layout of core and outrigger, arm length of outrigger and depth of outrigger and belt wall.

• International Journal of CAD/CAM
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• 제6권1호
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• pp.167-172
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• 2006

Recently, wire-EDM became a necessity for many engineering applications, particularly in the dies making. No-Core cut process is helpful for operations in which falling slug can jam the machine or wire. In this paper a proposed CAM system (called NCPP) is introduced, to overcome the limitations of the existing CAM systems in the machining of No-Core cut. The proposed CAM system (NCPP) provides pocketing of No-core cut and optimal selection of the position of starting hole (wire threading point), to minimize toolpath length. It was written for data exchange between CAD-CAM-CNC machines. This data model will become part of the ISO (Data model for Computerized Numerical Controllers) international standard. The NCPP system has been implemented in Visual C++. Many examples are used to illustrate NCPP system. The results show that, NCPP saves the machining time by significant value. This value depends on the shape and complexity of the workpiece that is being cut.