• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.2
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• pp.495-513
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• 2020

The correlation identification of the subsurface is a novel electrical prospecting method which could suppress stochastic noise. This method is increasingly being utilized by geophysicists. It achieves the frequency response of the underground media through division of the cross spectrum of the input & output signal and the auto spectrum of the input signal. This is subject to the spectral leakage when the cross spectrum and the auto spectrum are computed from cross correlation and autocorrelation function by Discrete Fourier Transformation (DFT, "To obtain an accurate frequency response of the earth system, we propose an improved correlation identification method which uses all phase Fast Fourier Transform (APFFT) to acquire the cross spectrum and the auto spectrum. Simulation and engineering application results show that compared to existing correlation identification algorithm the new approach demonstrates more precise frequency response, especially the phase response of the system under identification.

• Korean Journal of Computational Design and Engineering
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• v.5 no.2
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• pp.184-195
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• 2000

MDO (Multidisciplinary Design Optimization) methodology is an emerging new technology to solve a complicate structural analysis and design problem with a large number of design variables and constraints. In this paper MDO methodology is adopted through the use of computer aided systems such as Geometric Solid Modeller, Mesh Generator, CAD system and CAE system. And this paper introduces MDO methodology as a new method for structural analysis and design through the application to the structural design of flap drive system. In a MDO methodology application to the structural design of flap drive system, kinetodynamic analysis is done using a simple aerodynamic analysis model for the air flow over the flap surface instead of difficult aerodynamic analysis. Simultaneously the structural static analysis is done to obtain the optimum structural condition. And the structural buckling analysis for push pull rod is also done to confirm the optimum structural condition (optimum cross section shape of push pull rod).

• Journal of Korean Society of Steel Construction
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• v.24 no.5
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• pp.559-569
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• 2012

Cross-beam in the existing temporary bridge system is usually installed to prevent the lateral-torsional buckling of girders and to promote the construction efficiency. However, most of this cross-beams are connected to the girder web by bolts, and therefore, gravitational load resisting capacity of the cross-beams are negligibly small. In recent years, new temporary bridge system, in which the cross-beams and girders are connected to resist the external loads as a unit, was developed. In this paper, we present the experimental and analytical study results pertaining to the structural behavior and load carrying capacity of new temporary bridge system. From the results of study, it was found that the continuous cross-beam increased the flexural rigidity and reduced the maximum flexural stress in the girder. In addition, it was also found that the new temporary bridge system developed is more appropriate for the application in the long-span temporary bridge.

• Membrane Journal
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• v.9 no.1
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• pp.36-42
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• 1999

Permeation behavior of the semiconductor rinsing wastewater contammg Si particles was examined by ultrafiltration using the polyolefin tubular membrane. Flux decline with time was due to the growth of Si cake deposited on the membrane surface and the pore plugging by Si particles. Cake filtration from the cross flow application is compared to the combination of pore blocking and cake filtration from the dead-end application. The cake resistance is 3.16 x $10^{12}$ -4.34 X $\times$$10^{12}$ $m^{-1}$ for the cross flow and 6.6 x $\times$$10^{12}$ -12.19 X $\times$$10^{12}$ $\times$$m^{-1}$for the dead-end flow, respectively. At the initial stage of operation, permeation flux of cross flow type was 1.7 time higher than that of the dead end flow type. Permeation flux of cross flow was about 42 e 1m2 hr and the rejection rate of Si particles was about 96 %. The average particle size of Si particle in the permeate was 20 nm.

• Clean Technology
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• v.17 no.1
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• pp.13-18
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• 2011

Phosphine ligand-grafted mesoporous silica materials with large pores were prepared for the ligand-modified heterogeneous Pd nanocatalysts. New heterogeneous catalytic system was developed using palladium nanoparticles encapsulated in phosphine ligand-grafted mesoporous silica. The catalyst showed good catalytic activities for Suzuki cross-coupling using bromobenzene derivatives due to excellent phosphine ligand effects. Catalytic results showed nanoparticie catalysts can be recycled twice with decreased yields.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.2_2
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• pp.289-299
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• 2020

The composition of convergence cross-section of the material is a technique that provides reasonable design and construction of structures. It is frequently used in medium-sized bridges and architectural structures. However, the structural behavioral spare capacity enhancement of the structure by the application of the convergence cross-section is still limited by the expandability due to the limiting state of each material. In order to overcome these limitations, this study reasonably analyzed the construction stages before and after the convergence cross-section constructed and developed a technique for forming multi-point boundary conditions using struts, which are compression members. Based on the existing cases, a reasonable construction step for forming the material composite section of the entire structural system of the structure was derived, and a numerical analysis model for a specific part was constructed to analyze the behavior of the strut application. As a result of this study, the effect of reducing the sectional force of 7.40% in beam-column joint and 6.31% in the center of girder was derived, and the deflection, which is a measure of the serviceability of the structure, improved by 54.41% from the installation and dismantling of strut members at each construction stage.

• Journal of the Semiconductor & Display Technology
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• v.15 no.1
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• pp.47-51
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• 2016

Human visual system infers 3D vision through stereo disparity in the stereoscopic images, and stereo visioning are recently being used in consumer electronics which has resulted in much research in the application field. Basically, stereo vision system consists of four processes, which are cost computation, cost aggregation, disparity calculation, and disparity refinement. In this paper, we present and evaluate the existing various methods, focusing on cost aggregation for stereo vision system to comparatively analyze the performance of their algorithms for a given set of resources. Experiments show that Normalized Cross Correlation and Zero-Mean Normalized Cross Correlation provide higher accuracy, however they are computationally heavy for embedded system in the real time systems. Sum of Absolute Difference and Sum of Squared Difference are more suitable selection for embedded system, but they should be required on improvement to apply to the real world system.

• Journal of Electrical Engineering and Technology
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• v.4 no.1
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• pp.35-42
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• 2009

When two adjacent AC systems operate at different frequency such as 50Hz and 60Hz, as in the case of ROK and Russia, the only way to practically obtain the advantages of power system interconnection is to use HVDC connection. In this paper, application of the VSC-HVDC transmission for power system interconnection between Russia and ROK is evaluated through the PSCAD/EMTDC modeling and analysis. The simulation results show the feasibility of proposed system for cross border power system interconnection.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.2
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• pp.31-39
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• 2012

Recently new construction and reconstruction of the bridge have been required to minimize traffic congestion, environmental disadvantage, to reduce the period of construction, and to improve the quality and workability during the construction. For this reason, the application of modular bridge system, which is assembly of the structural members, is necessary to prepare for near future. Fall of girders can occur at the moment to connect between precast girders during the construction, so appropriate cross beams should be installed to solve the mentioned problem. In this study, understanding the structural characteristics and domestic and international case of cross beam, alternative cross beam system for modular bridge was developed. To inspect the structural characteristics of the alternative system, specimens were built and static loading test was performed. Afterward, the behavior of cross beam interms of joints and load distribution was observed. Experimental results were analyzed and compared with each data. Therefore, the appropriate cross beam system for modular bridge will be chosen and proposed in this paper.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.6
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• pp.10-19
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• 2003

As the technical demand for biometrics is increasing, users expect that fingerprint recognition systems are operable with various fingerprint readers. However, current commercial off-the-shelf fingerprint recognition systems are no interoperable due to the lack of standardization in application program interfaces for fingerprint readers. A cross-matching fingerprint recognition system is a person authentication system based on fingerprints and utilizing different types of fingerprint readers. It should be able to overcome variations in fingerprint images acquired by different readers, such as the size, resolution, contrast of images. The purpose of this research is to develop across-matching fingerprint recognition system for fingerprint research of different sensing mechanism. The fingerprint readers tested in this study are optical, semiconductor and thermal sensor modules, and the prpoposed cross-matching system utilizes both a minutiae-based similarity and a ridge count-based similarity in matching fingerprint images acquired by different sensors.