• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.944-950
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• 2008

When small cogenerators are operated in connected with power system, there are many positive aspects such as the reduction of power plant construction, making a improvement of power security etc. At the same time, there are some negative effects or difficulties such as we should make sure of protective coordination, especially, Actually these are not fault, but it is likely to consider the current as the fault. This is one of major causes of malfunctions for protective relays in power distribution system which is including interconnection point. Thus, in this paper, We showed that the directional protection is necessary to the dispersed generation system which is including connection point. We also executed contingency analysis to find out the magnitude of fault current and direction which are classified by fault points, length of line and kinds of faults using ETAP power system analysis program.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.3
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• pp.48-57
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• 2005

This paper presents a novel algorithm in order to extract lane-related information based on machine vision techniques. The algorithm makes up for the weak points of the former method, the Edge Distribution Function(EDF)-based approach, by introducing a Lane Boundary Pixel Extractor (LBPE) and the well-known Hough Transform(HT). The LBPE that serves as a filter to extract pixels expected to be on lane boundaries enhances the robustness of machine vision, and provides its results to the HT implementation and EDF construction. The HT forms the accumulator arrays and extracts the lane-related parameters composed of orientation and distance. Furthermore, as the histogram of edge magnitude with respect to edge orientation angle, the EDF has peaks at the orientations corresponding to lane slopes on the perspective image domain. Therefore, by fusing the results from the EDF and the HT the proposed algorithm improves the confidence of the extracted lane-related information. The system shows successful results under various degrees of illumination.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.65-68
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• 2003

This paper presents a design and construction of IIR multiple notch filter by modifying the pole-zero placement with least square estimation to find the appropriate gain and pole positions for the filter within a unit circle in z-plane. The appropriated gain and pole position will render the controllable unit gain of filter magnitude. Algorithm design and system simulation are performed on MATLAB while the actual implementation is done on the TMS320C31 digital signal processing board.

• Journal of Industrial Technology
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• v.17
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• pp.103-110
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• 1997

This thesis is to investigate the one-dimensional consolidation behavior of soft marine clay with uniform surcharges by perfoming numerical and experimental works. Parametric experimental works of centrifuge model test were carried out changing test conditions of gravitational level in centrifuge, magnitude of surcharges and construction sequence of applying surcharges. Results of centrifuge model experiments were analyzed by using the numerical technique of explicit finite difference method based on the finite strain consolidation theory, being known to be appropriate to analyze the consolidational behavior of soft clay with a very high initial void ratio using the Lagrangian and the material coordinate systems. Test results were in relatively good agreements with analyzed results in terms of excess pore pressure dissipation and consolidation settlement with time and final void ratio distribution.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.64.2-64.2
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• 2013

As more spectroscopic observations accumulate, it becomes evident that there are variations in light elements, such as C, N, O, and Na, between the sub-populations in most globular clusters (GC) in the Milky Way. We have constructed a new set of isochrones and horizontal branch evolutionary tracks with enhanced Nitrogen and depleted Oxygen to study their effects on the evolution of stars in GCs. From these results, we found that their effects on the evolution in color-magnitude diagram are significant in determining the age of GCs. In order to reflect these effects in the construction of population models for GCs, we have expanded the parameter space of Yonsei-Yale Isochrones and HB evolutionary tracks by introducing abundance enhancements of N for various global metal abundances and helium contents. In this paper, we will present our preliminary results from these calculations.

• Transactions of Materials Processing
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• v.22 no.1
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• pp.5-10
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• 2013

Steel plates are widely used in many manufacturing areas such as ship and bridge construction industries and are fabricated by different forming processes. Steel plates can have various shape defects, such as curl or camber. Roller leveling reduces the magnitude of the residual stress by using small amounts of reverse bending via an appropriate arrangement of the rolls and the associated plastic deformation in the steel plate. In this study a model for the residual stress after roller leveling is developed. In order to simplify the formulation, a plane-strain condition is assumed and the stress in the thickness direction is assumed to be negligible. The camber deformation in a real sized plate are measured and compared with the prediction values from the model to validate the accuracy of the model.

• Korean Journal of Hydrosciences
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• v.4
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• pp.81-92
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• 1993

This paper presents a model on the migration characteristics which is developed by using the equations for conservation of mass, momentum, and for lateral stability of the streambed. This model enables prediction of the magnitude the location of near-bank bed scour as well as rates and direction of meander migration in the sine-wave type revers (SWR) of small sinuosity. It is evident from this study that the transverse bed slope factor B' and transverse mass flux factor play significant roles in predicting migration characteristics, and their values of B'=4.0 and $\alpha$= 0.4 seem reasonable. This model will produce a useful quidelines in planning, design, construction, and development of SWR basin projects.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.1
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• pp.85-91
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• 1996

In the elM construction of naval architecture industry, ship hull surface modeling is critical process of design/manufacture process. This paper describes a fairing process of ship waterlines to represent boundary curves which are input data of surface modeling. Among the fairing methods, Sapidis's method and Rong's method are used in sequential to fair the boundary curves. Also it proposed four methods of determining the magnitude of end tangent vector. Among the four end tangents the best one is chosen by comparing with the shape of near curves. An application to the actual ship hull is given as an example.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.3-9
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• 2001

The Ms 7.7 earthquake of Gujarat, India occured early in the morning of January 26, 2001. Subsequent of the earthquake, as a Seismologist at Korea Institute of Geoscience and Mineral Resources(KIGAM), I have been visited epicentral area here reporting the impressions and initial observations collected during the period of Feb. 07 to 13. The trace of surface faulting was not founded. However the mechanism of the earthquake suggests the indenting Indian plate to the Eurasian plate was the tectonic background of this earthquake. Large casualties compare with the magnitude and focal depth of the event, seems due to the poor construction of the typical ordinary Indian housing structure. The wall and roof of the house are very thick to avoid high temperature of the epicentral region.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.721-726
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• 1999

Diverse strengthening methods for reinforced concrete are applied to real structures with a variety of materials. On the other hand, only external prestressing is used for strengthening damaged prestressed concrete girders. But the end brackets for external prestressing are hard to design and to manufacture, the magnitude of prestressing is limited when applied to real structures. The current end brackets are not clearly understood in load transmitting mechanisms and they may damage the original girder by drilling during construction. And also the designed welding area of the current bracket is insufficient to support the high load. The problems of current end bracket are solved in this study. And a new and improved end bracket is proposed and tested. The tested end bracket is similar to the end bearing bracket, but many supportting plates are addded to increase its welding length of the weakest point of the bracket. The increased welding length finally increases its load carrying capacity significantly.