• Earthquakes and Structures
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• v.5 no.2
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• pp.143-160
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• 2013

This paper presents the results of an experimental program concerning the efficiency of a specific strengthening technique which utilizes a small steel link element connected to the R/C frame through bracing elements. Brittle types of failure, especially at the connections between steel and concrete elements, can be avoided by appropriate design of the local details. Five single storey one bay R/C frames scaled 1:3 were constructed according to older codes with substandard details. The first one was a typical bare reference frame. The other four were identical to the first one, strengthened by steel bracing elements. The behavior of the strengthened frames is described with respect to the reference bare frame. The concrete frames were constructed according to older code provisions by the use of smooth steel bars, low strength concrete, sparsely spaced stirrups and substandard details. The strengthening scheme aimed to the increase of both strength and deformation capacity of the original R/C frame. The inelastic deformations are purposely concentrated to a short steel link element connecting the steel bracing to the R/C frame. The results show that the steel link element can increase considerably the strength and the energy dissipation capacity of the frame.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.7
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• pp.983-990
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• 2002

A numerical analysis has been carried out on forced convection heat transfer in the developing region of a porous channel. The channel is filled with an isotropic porous medium. At the channel walls, a uniform heat flux is given. Comprehensive numerical solutions are acquired to the Brinkman-Forchheimer extended Darcy equation and the LTNE model which does not employ the assumption of local thermal equilibrium between solid and fluid phases. Details of thermal fields in the developing region are examined over wide ranges of the thermal parameters. The numerical solutions at the fully developed region are compared with the previous analytical solutions. The correlation for predicting local Nusselt number in a porous channel is proposed.

• Nuclear Engineering and Technology
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• v.34 no.3
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• pp.202-210
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• 2002

The details of the electronic structure of the perfect crystal provides a critically important foundation for understanding the various defect states in uranium dioxide. In order to understand the local defect and impurity mechanism, the calculation of electronic structure of UO$_2$ in the one-electron approximation was carried out, using a semi-empirical tight-binding formalism(LCAO) with and without f-orbitals. The energy band, local and total density of states for both spin states are calculated from the spectral representation of Green’s function. The bonding mechanism in Perfect lattice of UO$_2$ is discussed based upon the calculations of band structure, local and total density of states.

• Journal of Sensor Science and Technology
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• v.29 no.2
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• pp.133-140
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• 2020

This study proposes a method of blending visible and near infrared images to enhance edge details and local contrast. The proposed method consists of radiance map generation and color compensation. The radiance map is produced by a Laplacian pyramid and a soft mixing method based on principal component analysis. The color compensation method uses the ratio between the composed radiance map and the luminance channel of a visible image to preserve the visible image chrominance. The proposed method has better edge details compared to a conventional visible and NIR image blending method.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.851-852
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• 2008

In this paper, we propose a tone mapping method using Non-linear Dynamic Range Normalization (NDRN) for High Dynamic Range (HDR) images. HDR images are not suitable for commercial display devices because dynamic range of HDR images do not match with one of Low Dynamic Range (LDR) display devices. To reproduce a tone of HDR images for LDR displays, tone mapping methods have been proposed such as local and global tone mapping. We introduce NDRN to locate mean of HDR images at the center of LDR. NDRN preserves the details for highlight and shadow. By suppressing the significant luminance change in tone mapping, naturalness of original image can be also preserved. The experimental results show that the proposed method preserves details and naturalness of original images.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.309-310
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• 2006

This paper presents an enhanced algorithm for compensating the visual quality in backlight image. Current cameras do not represent all details of scene into human's eye. Saturation and underexposure are common problems in backlight image. Retinex algorithm, derived from Land's theory on human visual perception is known to be effective in enhancing the contrast. However, its weaknesses are long processing time and low contrast of bright area in backlight scene because of compensating the details of dark area. In this paper, K-Retinex algorithm is proposed to reduce the processing time and enhance the contrast in both dark and bright area. To show the superiority of proposed algorithm, we compare the processing time and local variance of each area above.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.5
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• pp.601-607
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• 2018

Median filtering is a nonlinear method which is known to be effective in removing impulse noise while preserving local image structure relatively well. However, it could still suffer the smearing phenomena of edges and fine details into neighbors due to undesirable influence from the pixels whose values are far off from the true value of the pixel at hand. This drawback mainly comes from the fact that median filters typically employ a regular shape window for collecting the pixels used in the filtering operation. In this paper, we propose a median filtering method which employs an irregular shape filter window in collecting neighboring pixels around the pixel to be denoised. By employing an irregular shape window, we can achieve good noise suppression while preserving image details. Experimental results have shown that our approach is superior to regular window-based methods.

• The Journal of the Korea Contents Association
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• v.22 no.7
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• pp.126-135
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• 2022

Decentralization is a structural characteristic surrounding the allocation of power within an organization and is discussed at the organizational, national and local levels. This study examined the evaluation and decentralization direction of decentralization of public officials to derive problems and development directions of decentralization in Korea. We also derive our decentralization task. The decentralization task is, first, the expansion of autonomy in organization composition. The organization of local governments shall be determined according to the details and amount of local affairs. Second, it is to secure autonomy in personnel management. It is desirable for local governments to handle local gardens and manpower management autonomously rather than central uniform control. However, it is necessary to leave the checks and supervision to the local council, civic groups, and local residents. Third, the expansion of fiscal decentralization. First of all, the tax rate should be determined by ordinance within the scope prescribed by law to expand the autonomous financial authority. Next, it is necessary to expand local finances through the conversion of national taxes to local taxes. Next, it is necessary to expand local income taxes and local consumption taxes. Decentralization requires cooperation between the central and local governments and participation of local residents and stakeholders, breaking away from central unilateral and short-term thinking.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.2 s.314
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• pp.37-45
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• 2007

We propose an adaptive image enhancement method for epigraphic images, which is based on local statistics. Local statistics of the image are utilized for adaptive realization of the enhancement, that controls the contribution of the smoothing or sharpening paths. Image contrast enhancement occurs in details and noises are suppressed in smooth areas. For modeling the epigraphic image, pre~process is achieved by HSDI(Hanzi squeezed digital image). We have calculated the local statistics from this HSDI model. Application of this approach to HSDI has shown that processing not only smooths the background areas but also improves the subtle variations of edges, so that the word regions can be enhanced. Experimental results show that the proposed algorithm has better performance than the conventional image enhancement ones.

• Journal of Korean Society of societal Security
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• v.3 no.1
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• pp.33-42
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• 2010

This study predicts the stress history for truss bridge with local damages by using global-local model combination method. For this end, the global structure is modeled by 3D frame elements and the selected local details are modeled by shell elements. Then superposition principle enable the global-local model to be combined interactively. Because the frame model cannot consider the rigidity of gusset plate and the interation of structural members due to the complexity of stress distribution in truss connection. The section modification factors are proposed to calibrate the stiffness of global frame element. The global-local model combination is verified by comparing the numerical results with experimental data obtained from the proof loading test to the operating truss bridge. Furthermore, stress histrories of the truss bridge are generated in the consideration of the rigidity of truss connection with local damage by using the combination method.