• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.3
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• pp.296-301
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• 2012

This paper describes an analytic method for infrared thermography to detect surface cracks in thin plates. Traditional thermographic method uses the spatial contrast of a thermal field, which is often corrupted by noise in the experiment induced mainly by emissivity variations of target surfaces. This study developed a robust analytic approach to crack detection for thermography using the holomorphic function of a temperature field in thin plate under steady-state thermal conditions. The holomorphic function of a simple temperature field was derived for 2-D heat flow in the plate from Cauchy-Riemann conditions, and applied to define a contour integral that varies depending on the existence and strength of singularity in the domain of integration. It was found that the contour integral at each point of thermal image reduced the noise and temperature variation due to heat conduction, so that it provided a clearer image of the singularity such as cracks.

• Bulletin of the Korean Mathematical Society
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• v.61 no.4
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• pp.1033-1051
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• 2024

In this paper, we define a parametric variant of generalized Euler sums and construct contour integration to give some explicit evaluations of these parametric Euler sums. In particular, we establish several explicit formulas of (Hurwitz) zeta functions, linear and quadratic parametric Euler sums. Furthermore, we also give an explicit evaluation of alternating double zeta values ${\zeta}({\bar{2j}};\,2m+1)$ in terms of a combination of alternating Riemann zeta values by using the parametric Euler sums.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2001.11a
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• pp.17-22
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• 2001

This paper gave a review of form factor computations in the luminous flux transfer method and practical application of DiLaura's recently developed form factor computation. A systematic analysis of how the results of a contour integration solution differ from those of existing numeric solutions were undertaken with a developed computer simulation program. Various situations between sending and receiving surfaces were considered, including the facing, size, and distance between surfaces.

• Bulletin of the Korean Mathematical Society
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• v.45 no.2
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• pp.277-283
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• 2008

The paper deals with the values at the negative integers of a certain Dirichlet series related to the Riemann zeta function and with the expression of these values in terms of Bernoulli numbers.

• Bulletin of the Society of Naval Architects of Korea
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• v.16 no.4
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• pp.13-21
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• 1979

A method of evaluating Kelvin wave pattern is presented in this paper. The mathematical manipulation of x-derivative of the Green function of the Havelock source by the use of contour integration on the complex plane has resulted in the expression that can be readily incorporated with computer program. The efficiency and accuracy that can be secured by the use of the present mathematical expressions seem to be excellent when suitable numerical quadratures are employed. The wave patterns for particular submergences of the singularity are presented.

• Bulletin of the Korean Chemical Society
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• v.14 no.2
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• pp.238-243
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• 1993

A self-consistent-field Green's matrix method for the calculation of electronic properties of chemisorbed system is devised and applied to the methanol on copper(110) surface. The method is based on CNDO Hartree-Fock approximation. Contour integration in the complex energy plane is used for an efficient calculation of the charge-density bond-order matrix. The information on each fragment prior to chemisorption is efficiently used and a small number of iterations are needed to reach the self-consistency. The changes of density of states and other quantities of methanol due to chemisorption are consistent with reported experimental results.

• The Journal of the Korean dental association
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• v.55 no.10
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• pp.733-737
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• 2017

Successful osseo-integration of dental implants that Dr. Bronemak reported in 1965 had been ground-breaking research in the restorative dentistry for the missing dentition. Clinical application of dental implants in the restorative dentistry has begun with the role of retention and support for the complete denture, beyond the functional recovery in partially missing area, and succeeds in the cosmetic recovery for anterior missing area. Recently, immediate implantation and loading after the extraction have been preferred by many excellent clinicians especially on maxillary anterior missing area, because they want to prevent from the absorption of residual alveolar bone. But it is hard to decide immediate loading for common clinicians also, because it is difficult for them to convict proper osseo-integration. In this article, immediate implantation and delayed loading case on maxillay anterior region have been introduced and predictable prosthetic procedure for the esthetic result has suggested.

• Smart Structures and Systems
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• v.1 no.2
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• pp.159-184
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• 2005

The paper intends to summarize some guidelines for future smart structure system application in military aircraft. This preview of system integration is based upon a review on approximately one and a half decades of application oriented aerospace related smart structures research. Achievements in the area of structural health monitoring, adaptive shape, adaptive load bearing devices and active vibration control have been reached, potentials have been identified, several feasibility studies have been performed and some smart technologies have been already implemented. However the realization of anticipated visions and previously initial timescales announced have been rather too optimistic. The current development shall be based on a more realistic basis including more emphasis on fundamental aircraft strength, stiffness, static and dynamic load and stability requirements of aircraft and interdisciplinary integration requirements and improvements of integrated actors, actuator systems and control systems including micro controllers.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.3
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• pp.479-489
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• 1989

The $J_{k}$ integral method for determining mixed mode stress intensity factors separately in the cracked anisotropic plate is developed. Stress intensity factors are indirectly determined from the values of $J_{1}$ and $J_{2}$. The $J_{2}$ integral can be evaluated efficiently from a finite element solution, neglecting the contribution from the portion of the integration contour along the crack faces, by selecting the integration contour in the vicinity of the crack tip. Using functions of a complex variable, the complete relations between $J_{1}$, $J_{2}$ and $K_{I}$ , $K_{II}$ for anisotropic materials are derived conveniently by selecting narrow rectangular contours shrinking to the crack tip. Compared to the existing path independent integral methods, the present method does not involve calculating the auxiliary solution and hence numerical procedures become quite simple. Numerical results to various problems are given and demonstrate the accuracy, stability and versatility of the method.

• Composites Research
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• v.17 no.4
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• pp.25-31
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• 2004

In this study, a refined beam analysis model has been developed for multi-celled composite blades with elliptic cross-sections. Reissner's semi-complimentary energy functional is introduced to describe the beam theory and also to deal with the mixed-nature of the formulation. The wail of elliptic sections is discretized into finite number of elements along the contour line and Gauss integration is applied to obtain the section properties. For each cell of the section, a total of four continuity conditions are used to impose proper constraints for the section. The theory is applied to single- and double-celled composite blades with elliptic cross-sections and is validated with detailed finite element analysis results.