• Structural Engineering and Mechanics
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• 제37권3호
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• pp.267-283
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• 2011

Although earthquakes generate random cyclic lateral loading on structures, a quasi-static cyclic loading pattern with gradually increasing amplitude has been commonly used in the laboratory tests because of its relatively low cost and simplicity compared with pseudo-dynamic and shake table tests. The number, amplitudes and sequence of cycles must be chosen appropriately as important parameters of a quasi-static cyclic loading pattern in order to account for cumulative damage matter. This paper aims to reach a new cyclic displacement pattern to be used in quasi-static tests of well-confined, flexure-dominated reinforced concrete (RC) columns. The main parameters of the study are sectional dimensions, percentage of longitudinal reinforcement, axial force intensity and earthquake types, namely, far-fault and near-fault.

• 한국지진공학회논문집
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• 제20권2호
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• pp.91-101
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• 2016

This study is the compared seismic performance that are difference between the performance of structures on various site classes and beam-column connection. this analysis model was designed the previous earthquake load. To compare the performance levels of the structure was subjected to nonlinear static and nonlinear dynamic analysis. Nonlinear analysis was used to The Perform 3D program. Nonlinear static analysis was compared with the performance point and Nonlinear dynamic analysis was compared the drift ratio(%). Analysis results, the soft site class of the displacement was more increase than rock site classes of the displacement. Also The smaller the displacement was increased beam-column connection stiffness.

• 한국산업융합학회 논문집
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• 제15권1호
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• pp.29-36
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• 2012

Reinforced concrete shear walls and X-type steel braces were applied in seismic retrofit techniques for seismic performance evaluation of school buildings constructed in accordance with standard design announced by the ordinance of the ministry of construction in 1980s. Seismic performance evaluation was based on FEMA 356 using response spectrum as elastic analysis and conducted to pushover analysis with nonlinear static analysis. The maximum displacement ratio between floors in 4th and 3rd floors of the existing school buildings was less than 1.0%, which was functioning level in FEMA 356. However, because plastic hinge occurs somewhat in structural members according to the results of pushover analysis, partial reinforcement will be required. X-direction of the maximum lateral displacement of reinforced concrete shear walls than X-type steel braces was 45% and 32% in 4th and 3rd floors of school buildings, and Y-direction was 18% and 17%, respectively.

• 한국산업융합학회 논문집
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• 제9권3호
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• pp.199-206
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• 2006

Extraordinary displacement and vibration by heavy vehicle causes passengers to feel mental uncomfortableness and bridge to be damaged. To increase serviceability, the research on the human influence for vibration to happen at the bridge has been performed for a long time in oversea but it does not draw concern relatively in the domestic. The purpose of this research is to develop an evaluation method for vibration serviceability of continuous slab bridge. This research is focused on establishing theoretical method to assess vibration serviceability of bridge considering natural frequency, displacement, and acceleration since the criteria for the human responses to vibration is generally based on frequency band. By examining the characteristics of vibration serviceability which has been assessed with human response curve through field experiments as well as analytical study, the evaluation method of vibration serviceability for continuous slab bridges is proposed. Based on applications to the example of continuous slab bridge, the simple evaluation of vibration serviceability in the paper may be used in the initial step of design practice.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1997년도 Proceedings of the 13th KACG Technical Meeting `97 Industrial Crystallization Symposium(ICS)-Doosan Resort, Chunchon, October 30-31, 1997
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• pp.155-159
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• 1997

We investigated the effect of mechanical backside damage in Czochralski silicon wafer. The intensity of mechanical damage were evaluated by minority carrier recombination lifetime by a laser excitation/microwave reflection photoconductance decay method, photo-acoustic displacement method, X-ray section topography, and wet oxidation/preferential etch methods. The data indicate that the higher the mechanical damage intensity, the lower the minority carrier lifetime, and the photoacoustic displacement values are also increased proportionally.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.376-380
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• 2004

This paper is to develop an optical ruer displacement sensor for monitoring high speed spindle. Proper magnitude of optical power as well as amplification of output signal are necessary to improve sensitivity of the sensor. In this paper, to meet the need of improvement of the sensor resolution, we choose proper optical power and amplification level through speculating on optical power of a laser diode.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.1442-1447
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• 2005

Based on the field measuring data obtained from excavation sections in Inchon International Airport project, the relationships between the horizontal displacement of sheet-pile walls and the deformations of soft ground around the excavation were investigated. The horizontal displacements of walls according to supporting method are largely occurred in order of anchors, anchors with struts, and struts. The depths of maximum horizontal displacement are varied with supporting systems. If the stability number shows lower than ${\pi}$, the maximum horizontal displacement and the velocity of maximum horizontal displacement are respectively developed less than 1% of excavation depth and 1mm/day. When the stability number shows lower than ${\pi}+2$, the maximum horizontal displacement and the velocity are respectively developed less than 2.5% of excavation depth and 2mm/day. Also, when the stability number shows more than ${\pi}+2$, the maximum horizontal displacement and the velocity are rapidly increased.

• 한국지진공학회논문집
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• 제7권5호
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• pp.67-73
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• 2003

현 도로교의 내진해석은 구조물이 하중 이상의 강도를 갖도록 하는 하중기반해석법에 근거하고 있다. 본 연구에서는 이러한 하중기반해석의 대안책으로 구조물의 성능평가 대상을 변위로 하는 변위기반해석의 일종인 역량스펙트럼법을 제시하였다. 하중기반해석에서 내진설계가 수행되어진 기존 철근콘크리트 교각에 대하여 역량스펙트럼법에 의한 내진성능을 평가하였다. 그 결과, 역량스펙트럼법은 간편하고 신속하게 구조물의 비탄성 응답을 현실적으로 평가할 수 있었으며 비탄성 응답을 일으키는 다양한 지반운동 수준에 대해 구조물에 발생하는 변위를 평가할 수 있었고, 기존 구조물의 내진성능에 대한 평가나 신설구조물의 성능목표에 대한 설계검증에 효율적으로 적용 가능하였다.

• 전기학회논문지P
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• 제57권2호
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• pp.153-159
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• 2008

We have developed an absolute evaluation method to obtain the ratio error and phase displacement of a current transformer (CT) without any precise standard CT by measuring four parameters in a CT equivalent circuit. The excitation admittance in the CT equivalent circuit can be obtained by employing standard resistors with negligible reactive component. The secondary leakage impedance in the CT equivalent circuit can be measured using a universal impedance bridge. The method was applied to CTs under test with the wide current ratios in the range of 5 A / 5 A - 5,000 A / 5 A and 5 A / 1 A - 5,000 A / 1 A. The ratio error and phase displacement of the CT under test obtained in this study are consistent with those measured at the national institute in Canada using the same CT under test within an expanded uncertainty (k = 2) in the overall current ratios.

• 센서학회지
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• 제28권1호
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• pp.58-63
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• 2019

This research aims at designing a diaphragm made of SUS316L stainless steel for ultra high pressure sensors and evaluating its performance with a PZT driven deformation tester instead of high pressure chamber testing up to 100 MPa. Finite element method analysis indicates that the optimum thickness of a flat diaphragm is 1.5 mm not only to secure safety of sensors up to 100 MPa but also to enhance displacement measuring sensitivity. For this thickness, the maximum displacement at the center of the diaphragm is $5.3{\mu}m$. The PZT actuator must offer a force of 1,669 N to create a pressure of 100 MPa at the diaphragm surface in order to obtain a displacement of $5.3{\mu}m$. The performance evaluation by the PZT driven tester demonstrates nearly the same results as the same results as the sensors tested in the ultra high pressure chamber.