• Journal of the Korean Geotechnical Society
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• v.25 no.4
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• pp.69-75
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• 2009

The load distribution and deformation of pile-bent structures are investigated using a numerical study. A numerical analysis that takes into account the effects of varying cross-sectional area was performed for different pier diameters, loading steps, and soil conditions. Through the comparison study, it is shown that the location of maximum bending moment is almost the same per each loading step, regardless of varying cross-sections. However, the member force (i.e., stress of pile material) has the largest value at the ground surface when the cross-section is changed. Based on the results obtained, it is found that the location of maximum member force influences highly the behavior of pile-bent structure with varying cross-sections for repair works.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.3
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• pp.615-622
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• 2007

In general, Harris detector is commonly used for finding salient points in watermarking systems using feature points. Harris detector is a kind of combined comer and edge detector which is based on neighboring image data distribution, therefore it has some limitation to find accurate salient points after watermark embedding or any kinds of digital attacks. In this paper, we have used cross reference points which use not data distribution but geometrical structure of a normalized image in order to avoid pointing error caused by the distortion of image data. After normalization, we find cross reference points and take inverse normalization of these points. Next, we construct a group of triangles using tessellation with inversely normalized cross reference points. The watermarks are affine transformed and transformed-watermarks are embedded into not normalized image but original one. Only locations of watermarks are determined on the normalized image. Therefore, we can reduce data loss of watermark which is caused by inverse normalization. As a result, we can detect watermarks with high correlation after several digital attacks.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.10
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• pp.891-895
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• 2005

Novel structure ultrasonic motors which have cross type stator were designed and fabricated. Driving characteristics of the motors were analyzed and measured by changing the materials of the stator. This ultrasonic motor has stator with hollowed cross bar and the stator rotate the rotor using elliptical displacement of the inside tips. This motion is generated by lateral vibration mode of cross bars. This stator was analyzed by finite element analysis depandent on stator's materials. And the cross type ultrasonic motors were made by analyzed results. The larger displacements were obtained, when the density of material was decreased. But the stress was increased when the stator's material has large density and Young's modulus. The fabricated one has high speed and torque in large stress on contact point between rotor and stator. The stress was more effected on speed and torque than the displacement.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.236-239
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• 2002

The electron-atom collision studies has been essentially use\ulcorner for testing and developing suitable theories of the scattering and collision processes, and for providing a tool for obtaining detailed information on the structure of the target atoms and molecules and final collision products. And, the development of that has also been strongly motivated by the need for electron collision data in such fields as laser physic and development, astrophysics, plasma devices, upper atmospheric processes and radiation physics. Therefore, we explains the concept and the principle of determination of the electron collision cross sections for atoms and molecules by using the present electron swarm method.

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.2
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• pp.117-127
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• 2000

In this paper, we propose a new convex combination weight rule for the cross decomposition method which is known to be one of the most reliable and promising strategies for the large scale optimization problems. It is called generalized cross decomposition, a modification of linear mean value cross decomposition for specially structured linear programming problems. This scheme puts more weights on the recent subproblem solutions other than the average. With this strategy, we are having more room for selecting convex combination weights depending on the problem structure and the convergence behavior, and then, we may choose a rule for either faster convergence for getting quick bounds or more accurate solution. Also, we can improve the slow end-tail behavior by using some combined rules. Also, we provide some computational test results that show the superiority of this strategy to the mean value cross decomposition in computational time and the quality of bounds.

• Nuclear Engineering and Technology
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• v.46 no.4
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• pp.475-480
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• 2014

We developed a simple method to prepare the displacement damage cross section of SiC using NJOY and SRIM/TRIM. The number of displacements per atom (DPA) dependent on primary knock-on atom (PKA) energy was computed using SRIM/TRIM and it is directly used by NJOY/HEATR to compute the neutron energy dependent DPA cross sections which are required to estimate the accumulated DPA of nuclear material. SiC DPA cross section is published as a table in DeCART 47 energy group structure. Proposed methodology can be easily extended to other materials.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.5
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• pp.435-440
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• 2003

The electron-atom collision studies have been essentially used for testing and developing suitable theories of the scattering and collision processes, and for providing a tool for obtaining detailed information on the structure of the target atoms and molecules and final collision products. And, the development of that has also been strongly motivated by the need for electron collision data in such fields as laser Physics and development, astrophysics, Plasma devices, upper atmospheric processes and radiation physics. The concept and the Principle of determination of the electron collision cross sections for atoms and molecules by using the present electron swarm method are explained.

• Journal of Ocean Engineering and Technology
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• v.17 no.4
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• pp.59-65
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• 2003

In order to achieve the desired lightweight and robust design of a structure, it is preferable to design a structure and its control system, simultaneously, which is termed the combined optimal design. A constant-cross-sectional area cantilever beam was chosen as the optimum design method, An initial load and a time-varying disturbance were applied at the free end of the beam. Sliding mode control was selected, due to its insensitivity to the disturbance, compared with other modes. It is known that the sliding mode control is robust to the disturbance and is uncertain, only if a matching condition is met, after giving a switching hyper plane. In this study, the optimum method was used for the design of the switching hyper plane, and the objective function of the optimum switching hyper plane was assumed to be the objective of the control system. The total weight of the structure was treated as a constraint, and the cross sectional areas of the beam were considered as design variables, the result being a nonlinear programming problem. To solve it, the sequential linear programming method was applied. As a result of the optimum design, the effect of attenuating vibrations has been substantially improved. Moreover, the lightweight design of the structure became possible as a result of the relationship of the weight of the structure to the control objective function.

• Journal of the Korean Operations Research and Management Science Society
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• v.42 no.2
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• pp.49-61
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• 2017

The study on the efficiency analysis of Korean automobile parts companies is mostly based on the calculation of the size of output such as sales. However, the performance indicators such as sales, operating profit, and net profit are directly related to the cost structure, and this cost structure is affected by changes in the company's asset structure and capital structure. As a result, it is necessary that efficient capital procurement should be done at the same time to create efficient management performance through proper investment. In this study, we aim to measure the efficiency of asset and capital procurement compared to the sales figures, such as sales, generated by 33 primary suppliers who supply parts to Hyundai Kia Motors. For this purpose, this study proposed a DEA cross analysis model that can simultaneously measure efficiency in terms of input assets and capital procurement based on the same management performance when analyzing the efficiency of domestic auto parts companies.

• International Journal of High-Rise Buildings
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• v.3 no.3
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• pp.205-214
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• 2014

The super high rise building construction is characterized by a large quantity of engineering works and structural components, high demanding of construction technology and complex cross operations. As the height of super high rise building increases, the construction difficulties increase, it is challenging the steel structural building construction technology. In this paper, the key technologies in the construction of Chinese modern super high rise steel structure building have been studied. The innovative tower crane supporting frame suspension disassembly technology has been developed to allow the crane supporting frame to turnover in the air without occupying materials stockyard. A new self-elevating platform technique which is capable of striding over structural barriers has been developed. This new technology allows the platform to be self-elevated along variable cross section column with a maximum 600 mm size change. A new automatic submerged arc welding technology has also been developed to ensure the process continuity and quality stability of welding job on the construction site.