• Journal of Conservation Science
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• v.22
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• pp.31-42
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• 2008

A stone cultural heritage often lacks design drawing and detailed geometric informations, thus it becomes more difficult to conservation and restoration. Even though there is active database of detail shape information and numerical measurement for stone monuments, most of the data is in hard-to-utilize two-dimensional images. The new technology developed to overcome this problem is three-dimensional image scanning system. The multi-storied stone pagoda of the Daewonsa temple was analysed with 3D scanning image data then survey map with orientation displacement was evaluated. The difference of each side became apparent with the members of the stone properties was measured, also horizontal and vertical displacement occurred. Horizontal displacement occurred in increasing severity from left to right and from body section to upper part. The 8th roof stones are leaning toward northwest direction due to lateral displacement. The evaluation and measurement of displacement could cause a little errors due to the characteristics uneven surface of stone monuments, computer program and mistakes from the researcher. In future, more precise measurement and stability studies should be done to suggest that accurate data for conservation and understanding of damage condition can be provided.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.4 s.19
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• pp.49-57
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• 2005

The purpose of this study is to closely examine the influence of the surcharge load applied to the retaining wall through some model tests, in which wall stiffness in each stage of excavation, horizontal displacement of the retaining wall and surface displacement of the backfill according to wall stiffness and ground conditions, and change and distribution of the earth pressure applied to it were measured and their values were produced, then these values were mutually compared with their theoretical values and their values after analysis of the data obtained at the field, and they were analytically studied, in order to closely examine the influence of the surcharge load applied to the retaining wall. Findings from this study are as follows: The shape of ground surface settlement curve on the model ground under surcharge load, different from the distribution curve of regular probabilities which is of a shape of ground surface settlement under no surcharge load, appears in that settlement in an arching shape shows where the center part of surcharge load shows the maximum settlement. In examining the maximum horizontal displacement with the surcharge load applied to each stage of excavation, it occured at the point of 0.8H(excavation depth) when finally excavated. Regarding the range in which the displacement of the retaining wall increases according to application of surcharge load, the increment of displacement showed till the point of depth which is of two times of the distance of load from the upper part of the wall. Also since each displacement of the foundation plate caused by the ground surface settlement according to each stage of excavation occured most significantly at the final stage. Also since regarding wall stiffness, the wall of its thickness of 4mm(flexible coefficient $p:480m^3/t$), produced maximum 3 times of wall stiffness than its thickness of 9mm(flexible coefficient $p: 40m^3/t$), it was found out that influence of wall stiffness is so significant.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.181-186
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• 1993

Thermal expansion of ball screw in the semi-closed loop type CNC LATHE introduces positioning errors directly along the travelling the axis. In this paper the thermal displacements of the ball screw were estimated by using macro variable. The estimated displacements of the ball screw were given to the ball screw of the CNC LATHE under the constant driving conditions were measured to examine the effectiveness of the compensation method. The results showed that thermal displacements of the ball screw could be maintained less then 6 .mu.m positioning accaracy while using this compensation.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.86.1-86
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• 2001

Combined with a counter, wheel or strip encoders which have equally divided markers are one of frequent measuring choices towards various applications in terms of cost, simplicity, and diversity of measurements, e.g., measuring displacement, velocity, acceleration, and so on. Often, velocity is measured by counting the series of reference clocks for a period of time which sensor-carrying device took for traveling two adjacent encoding markers. Quantizaion error of such that the disturbance caused by quantization error is under control. This paper identifies design issues, developes theory, and proposes a paradigm to design a velocity measurement system such ...

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.364-369
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• 2003

Crack propagation and AE characteristics of CFRP plain woven laminate composites are examined with acoustic sensor by AEDSP 32/16 board in PC system. AE signals are measured during the fracture behavior tests. The purpose of study is the estimation of the crack extension behavior effected between three kinds of fiber orientation for plain woven CFRP laminate composite and the relationship between AE characteristics and load-displacement curves and crack extension length.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.71-75
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• 1998

This study deals with the friction weldability of A7075-T6 having high specific strength. The friction welding conditions used are rotation speed 2000rpm, friction pressure 40MPa, friction time 1.5sec, upset pressure 40~100MPa, upset time 5sec. First, upset length was measured by displacement transducer. The plastic flow in 7075-T6 weld generates convex lens shaped resion by friction and concave lens shaped resion by axial force. Under the condition of upset pressure 85MPa, the friction welds have tensile strength of 552MPa and shear strength of 262MPa.

• Journal of Welding and Joining
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• v.22 no.2
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• pp.33-37
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• 2004

Since the preflex beam is fabricated by welding, the pre-compressive stresses that should occur over the concrete pier are diminished by the welding residual stresses. For this reason distribution of welding residual stresses must be analyzed accurately and welding residual stresses should be relieved during the fabrication. In this study strain history, displacement of beam and re-distributed welding residual stresses by different loading conditions are measured and compared to choose more appropriate preflex condition.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.529-533
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• 1994

Atrains in microstain range are measured accurately by means of holographic interometric technique. Holographic fringes of the cantilever beam subjected to out-of-plane deflection and in-plane deflection respectively are obtained experimentally. Form these fringe patterns, 3rd order polynomial of displacements is induced using polynomial regression method. And strain stress distribution could be determined from the secound derivative of this polynomial. These results agree well with FEM.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.10a
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• pp.275-282
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• 1999

In this study, the algorithm which can estimate displacements from the acceleration data is developed. For proving the validity of this study, the calculated displacements are compared with the measured displacements through the forced vibration tests in the laboratory. So the sampling frequency and filtering range for the estimation of the displacements are proposed. Finally, these results are applied to estimate displacements from the acceleration data obtained from the real bridge.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.418-423
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• 2005

In designing underground structure such as tunnels, estimating geotechnical characteristics of the ground is one of the most important and difficult tasks. In this paper, a methodology that can identify geotechnical parameters using only field-measured relative convergence displacements is presented. By using only relative convergence measurement data, inevitable errors in absolute convergence estimation can be avoided and in turn the parameter estimation process can be simplified. The methodology utilizes sensitivity relationship between static displacement measurements and geotechnical parameters. The feasibility and applicability of the proposed methodology is verified via a 3-d numerical example of a tunnel structure.