• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.214-215
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• 2020

The 3D scanning technology is being introduced for quality inspection of building construction. Therefore, this study tried to confirm whether it is possible to check the quality of rebar by using 3D scanning. After rebar placed on the formwork slab was scanned with a 3D scanner, the rebar spacing was confirmed by overlapping with the CAD drawing. As a result, the 3D scanner was able to check the quality of rebar work on one floor at a time. Therefore, 3D scanning could be used for quality inspection of rebar works such as columns, beam and girders, walls, and slabs in the future.

• International Journal of CAD/CAM
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• 제5권1호
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• pp.91-98
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• 2005

This paper presents a scheme for interpolating intersecting uniform cubic B-spline curves by Catmull-Clark subdivision surfaces. The curves are represented by polygonal complexes and the neighborhoods of intersection points are modeled by X-Configurations. When these structures are embedded within a control polyhedron, the corresponding curves will automatically be interpolated by the surface limit of subdivision of the polyhedron. The paper supplies a construction which clearly shows that interpolation can still be guaranteed even in the absence of symmetry at the X-configurations. In this sense, this scheme generalizes an already existing technique by the same authors, thereby allowing more freedom to designers.

• 한국전산유체공학회지
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• 제6권4호
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• pp.15-25
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• 2001

Numerical prediction of the diffusion controlled transition in a turbine gas pass is important because it can change the local heat transfer rate over a turbine blade as much as three times. In this study, the gas flow over turbine blade is simplified to the flat plate boundary layer, and an adaptive grid scheme redistributing grid points within the computation domain is proposed with a great emphasis on the construction of the grid control function. The function is sensitized to the second invariant of the mean strain tensor, its spatial gradient, and the interaction of pressure gradient and flow deformation. The transition process is assumed to be described with a κ-ε turbulence model. An elliptic solver is employed to integrate governing equations. Numerical results show that the proposed adaptive grid scheme is very effective in obtaining grid independent numerical solution with a very low grid number. It is expected that present scheme is helpful in predicting actual flow within a turbine to improve computation efficiency.

• 한국물환경학회지
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• 제24권3호
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• pp.297-305
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• 2008

It is necessary to select proper reduction methods and to calculate reasonably reduction amount for making good practice of the reduction scheme. Moreover, it is suggested that the reduction amount have to be distributed properly during the planning period. In other words, it has not to be concentrated on the specific year (especially final year of the planning period). The reason why, if the reduction amount concentrate on the final year of the planning period, allotment loading amount could not be achieved in some cases (e.g., insufficiency of budget, extension of construction duration). Even though much of the budget have been supported from national treasury (about 50%), it is thought the role of the local government must be strengthened gradually.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2002년도 추계 학술발표회 논문집
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• pp.51-60
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• 2002

In this study we developed the visualization scheme of spatial ground-motion measurements in real time by using DSS data. Even though this scheme itself is useful for national earthquake mitigation plans, this scheme could be served as the crucial core for constructing rapid earthquake damage evaluation system. DSS is the abbreviation of Data Subscription Service and this is the pre-assigned request for the seismic stations to send very limited brief data with high priority and negligible transmission load. In addition to visualize the damage area with intensity, the corresponding epicenter can be estimated roughly for quick event alarm. For the interpolation of spatially irregular PGA data, the program, named as surface. of GMT was used with NetCDF grid file format. Since the grid file is similar to a postscript file, the program, called as shading, was coded with C language by using Matpak library in order to convert grid files into image files.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.1731-1734
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• 2003

In this paper, we describe an approach for image denoising using the lifting construction, with the spatial adaptive wavelet transform. The adaptive lifting scheme is implemented in spatial domain to be adjusted thresholds to reduce noise. In this approach we represent adaptive characteristics of biorthogonal wavelets for choosing predictors effectively. Predict filter is changed from sample to sample according to local signal features with their vanishing moments. We in this approach have implemented and applied to image denoising by finding a relevant minimax threshold. Experimental results show that the adaptive method of denoising process is compared with existing ones, such as non-adaptive wavelet, CRF(13, 7) and SWE(13, 7) wavelets used by JPEG2000.

• 한국통신학회논문지
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• 제23권6호
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• pp.1546-1553
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• 1998

본 논문에서는 복잡한 암호학적 연산없이 숨겨진 화상을 복원할 수 있는 시각암호를 이용한 개인 인증 방식에 대하여 고찰한다. Katoh와 Imai는 1개의 표시화상에 인증을 위한 2개의 질문 화상을 숨길 수 있는 방식을 제안하였다. 이 방식을 확장시켜 복수개의 질문화사을 숨길 수 있는 일반화 구성법을 제시한다. 나아가, Droste방식을 적용시켜 모든 슬라이드의 조합에 따라 서로 다른 비밀화상을 숨길 수 있는 방식을 제안한다.

• Journal of Communications and Networks
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• 제17권2호
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• pp.157-161
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• 2015

A new block low-density parity-check (Block-LDPC) code based on quadratic permutation polynomials (QPPs) is proposed. The parity-check matrix of the Block-LDPC code is composed of a group of permutation submatrices that correspond to QPPs. The scheme provides a large range of implementable LDPC codes. Indeed, the most popular quasi-cyclic LDPC (QC-LDPC) codes are just a subset of this scheme. Simulation results indicate that the proposed scheme can offer similar error performance and implementation complexity as the popular QC-LDPC codes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.304-307
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• 1998

High speed railway is under construction from Seoul to Pusan. A traveling train is large single phase load that consumes 14MW power in feeding system of high speed railroad. In this paper, measurement scheme and method of power system harmonics which are generated from those loads in railroad supply system are described. This measurement scheme will be used as a first step to pave a way to power quality management due to harmonic distortion by the highspeed rail way.

• 한국구조물진단유지관리공학회 논문집
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• 제3권2호
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• pp.221-232
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• 1999

This study investigates the applicability and design scheme of fieldbus network in the measurement system used for precise and safe construction as well as efficient maintenance of bridges. In order to maximize the function and performance of bridge monitoring system, this study introduces the CAN(Controller Area Network), one of the fieldbus protocols, in the measurement system of bridges. This study presents the implementation method of CAN on the monitoring system of bridge, and also proposes a bandwidth allocation scheme for the design of network. The validity of the proposed CAN design method is verified through a simulation experiment. It is shown that the CAN can be readily applicable to the measurement system of bridges.