• 한국가시화정보학회:학술대회논문집
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• 2004.12a
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• pp.15-23
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• 2004

The present study is aimed to achieve dynamic visualization from the in-house 3-D stereoscopic PIV to represent quantitative flow information such as time-resolved 3-D velocity distribution, vorticity, turbulent intensity or Reynolds stresses and so on. One of the application of the present study is Leading edge extension(LEX) flow appearing on modern delta wing aircraft. The other is mixing flow in stirring tank used in industry field. LEX in a highly swept shape applied to a delta wing features the modern air-fighters. The LEX vortices generated upon the upper surface of the wing at high angle of attack enhance the lift force of the delta wing by way of increased negative suction pressure over the surfaces. The present method resolves also the complicated flow patterns of two type impellers rotating in stirring vessel. Flow quantities such as three velocity vector components, vorticity and other flow information can be easily visualized via the 3D time-resolved post-processing visualization. And it makes the easy understanding of the unsteady flow characteristics of the typical industrial mixers.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.4
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• pp.371-382
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• 2001

The recognition of such natural wave guides as plates, rods, hollow cylinders, multi-layer structures or simply an interface between two materials combined with an increased understanding of the physics and wave mechanics of guided wave propagation has led to a significant increase in the number of guided wave inspection applications being developed each year. Of primary attention Is the ability to inspect partially hidden structures, hard to access areas, and teated or insulated structures. An introduction to some physical consideration of guided waves followed by some sample problem descriptions in pipe, ice detection, fouling detection in the foods industry, aircraft, tar coated structures and acoustic microscopy is presented in this paper. A sample problem in Boundary Element Modeling is also presented to illustrate the move in guided wave analysis beyond detection and location analysis to quantification.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1049-1052
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• 2010

생산성 및 품질혁신을 위하여 Lean 6시그마에 대한 다양한 국외 적용사례는 존재하나, 고도의 하이테크 산업이며 품질을 최우선으로 삼는 항공산업에 적용 및 평가에 대한 국내 연구사례는 거의 전무한 것이 현실이다. 본 연구에서는 린 6시그마 기법이나 사상들이 국내 항공산업 프로세스의 생산성 및 품질을 향상시키는데 과연 적합한지 판단하여, 현장적용을 사례로 적용 방법론을 제안하는데 목적이 있다.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.689-690
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• 2006

The development method of a pneumatic solenoid actuator which is used as key components in automobile and aircraft industry is described. For the optimal design of solenoid actuator, we applied the general electromagnetic theory and empirical knowledge. By using the governing equation for the solenoid actuator based on the electromagnetic theory and empirical coefficient, and constrained of optimization technique, we proposed the optimal design technique of low consumption type DC solenoid actuator. The design results of the DC 24V, 0.5W solenoid actuator were presented.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1148-1153
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• 2004

Recently the high speed end-milling processing is demanded the high-precise technique with good surface rougj1ness and rapid time in aircraft, automobile part and molding industry. The working factors of high speed end-milling has an effect on surface roughness of cutting surface. Therefore this study was carried out to analyze the working factors to get the optimum surface roughness by design of experiment. From this study, surface roughness have an much effect according to priority on Spindle speed, feed rale, hardness and axial depth of cut By design of experiment, it is effectively represented shape characteristics of surface roughness in high speed end-milling And determination($R^2$) coefficient of regression equation had a satisfactory reliability of 89.7% and regression equation of surface roughness is made by regression analysis.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.473-476
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• 2005

Today's manufacturing industry is facing challenges from advanced difficult-to-machine materials (WC-Co alloys, ceramics, and composites), stringent design requirements (high precision, complex shapes, and high surface quality), and machining costs. Advanced materials play an increasingly important role in modem manufacturing industries, especially, in aircraft, automobile, tool, die and mold making industries. The greatly-improved thermal, chemical, and mechanical properties of the material (such as improved strength, heat resistance, wear resistance, and corrosion resistance), while having yielded enormous economic benefits to manufacturing industries through improved product performance and product design, are making traditional machining processes unable to machine them or unable to machine them economically. In this paper, mechanical characteristic evaluation test of fine powder type WC-Co alloy was accomplished to obtain clear data for miniaturized special die parts machining with high reliability and high quality.

• Journal of Applied Reliability
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• v.3 no.1
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• pp.73-82
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• 2003

Reliability Centered Maintenance(RCM) was initially developed for the commercial aviation industry in the late 1960s and now is equally applicable to a variety of equipment other than aircraft. RCM is a method for establishing a preventive maintenance program which will efficiently and effectively allow the achivement of the the required safety and availability levels of equipment and structures. RCM provides for the use of a decision logic tree to identify applicable and effective preventive maintenance requirements for equipment and structures according to the safety, maintenance requirements for equipment and structures according to the safety, operational and economic consequences of identifiable failures, and the degradation mechanism, reponsible for the those failures. The end result of working through the decision logic is a judgement as to the necessity of performing a maintenance task. In this paper, we provide guiding principles based on IEC 60300-3-11 for RCM analysis methods and operational method of structure and equipment.

• Advances in aircraft and spacecraft science
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• v.2 no.3
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• pp.249-261
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• 2015

The mechanical characterization of composite materials is nowadays a major interest due to their increasing use in the aeronautic industry. The design of most of these materials is based on their stiffness, which is mainly obtained by means of tensile tests with strain gauge measurement. For thin laminated composites, this classical method requires adequate samples with specific orientation and does not provide all the independent elastic constants. Regarding ultrasonic characterization, especially immersion technique, only one specimen is needed and the entire determination of the stiffness tensor is possible. This paper presents a study of different methods to determine the mechanical properties of transversely isotropic carbon fibre composite materials (gauge and correlation strain measurement during tensile tests, ultrasonic immersion technique). Results are compared to ISO standards and manufacturer data to evaluate the accuracy of these techniques.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.52-53
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• 2017

Through the case study, we surveyed an applicability of digital fabrication in irregular-shaped building construction project. By digital fabrication, we mean is a precision manufacturing method has been used in aircraft, ship and car manufacturing industry. We collected construction-completed "LotteWorld Tower Podium" project data and analyzed its process in terms of construction quality andduration. The result shows that digital fabrication is considered a competitive technology that enabled to complete the project in seven months within 3mm surface curvature threshold. The digitalfabrication is expected to apply on a number of irregular-shaped building construction project.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.6
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• pp.52-59
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• 2004

Recently the high speed end-milling processing is demanded the high-precise technique with good surface roughness and rapid time in aircraft, automobile part and molding industry. The working factors of high speed end-milling has an effect on surface roughness of cutting surface. Therefore this study was carried out to analyze the working factors to get the optimum surface roughness by design of experiment. From this study, surface roughness have an much effect according to priority on distance of cut, feed rate, revolution of spindle and depth of cut. By design of experiment, it is effectively represented shape characteristics of surface roughness in high speed end-milling. And determination($R^2$) coefficient of regression equation had a satisfactory reliability of 76.3% and regression equation of surface roughness is made by regression analysis.