• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.43 no.5
• /
• pp.848-860
• /
• 1994

Generally, to get the minimum distance between two arbitrary shapes that are composed of circular arcs and lines, we must calculate distances for all the possible pairs of the components from two given shapes. In this paper, we propose an efficient method for the minimum distance problem between two shapes by using their structural features after extracting the reduced component lists which are essential to calculate the minimum distance considering the relationship of shape location. Even though the reduced component lists may contain all the components of the shapes in the worst case, in the average we can reduce the required computation much by using the reduced component lists. This method may be efectively applied to calculating the minimum distance between two shapes which are generated by the CAD tool, like in the nesting system.

• Proceedings of the KIEE Conference
• /
• 1999.07g
• /
• pp.2809-2811
• /
• 1999

In this paper, we develope an algorithm to calculate field inhomogeneity in MR imaging using a dual fast spin echo pulse sequence. Because phase modulation time can be easily modified with this pulse sequence, high resolution image can be obtained and acquisition time can be reduced compared to gradient echo technique. In the case of phase wrapping in field map, phase corrected using image processing technique. We assume the field pattern to be second order polynomial and apply Pseudo-Inverse equation to calculate second order polynomial coefficients. These coefficients can be used for the shimming of the magnetic field.

• Proceedings of the KIEE Conference
• /
• 1993.07a
• /
• pp.134-136
• /
• 1993

This paper presents a novel and efficient method to calculate the critical point of voltage collapse. Conjugate gradient and modified Newton-Raphson methods are employed to calculate two pairs of multiple load flow solutions for two operating conditions, i.e., both +mode and -mode voltages for two loading conditions respectively. Then these four voltage magnitude-load data sets of the bus which is most susceptible to voltage collapse, are fitted to third order polynomial using Lagrangian interpolation in order to represent approximate nose curve (P-V curve). This nose curve locates first estimate of the critical point of voltage collapse. The procedure described above is repeated near the critical point and the new estimate will be very close to the critical point. The proposed method is tested for the eleven bus Klos-Kerner system, with good accuracy and fast computation time.

• Proceedings of the KIEE Conference
• /
• 1993.07a
• /
• pp.177-179
• /
• 1993

Best generation mix belongs to a multi attribute decision making, because we should consider many uncertain factors and choose the best one of the alternatives. Sugeno's fuzzy integral has been used as the solution of multi attribute decision making, but the exact value of the coefficient $\lambda$ hat not known yet which is needed to calculate fuzzy measure. This paper proposes the new method to calculate fuzzy measure without fixing the value of $\lambda$. The proposed method considers $\lambda$ as a probability distribution function and calculated expectation of fuzzy measure. The method is applied to the test system and the validity of the method is verified.

• Proceedings of the KIEE Conference
• /
• 1993.07a
• /
• pp.64-66
• /
• 1993

This paper presents an efficient method to calculate voltage collapse point and to improve static voltage stability. To evaluate static voltage stability in power systems. it is necessary to get critical loading points. For this purpose, we use linear programming to calculate efficiently voltage collapse point. And if index value becomes larger than given threshold value, vol tags stability is improved by compensation of reactive power at selected bus. This algorithm is verified by simulation on the sample system.

• The Journal of Engineering Geology
• /
• v.11 no.2
• /
• pp.131-139
• /
• 2001

Until recently, limestone yield production is mainly depend on geological investigation and boring. In the study seismic and electrical method are applied to calculate the basic data of limestone yield production. the result of geophysical prospecting, the depth of bed rock is approximately 17m. And there is a slightly difference between the limestone layer boundary which is drawn by electrical prospecting method and that of geological investigation.

• Economic and Environmental Geology
• /
• v.32 no.6
• /
• pp.661-667
• /
• 1999

Estimation of inflow rates into subsection of a tunnel is establishing the proposed grouting part, measuring the degree of grouting, and settling the dispute over deplrtion of groundwater which may be resulted from tunneling. A current meter was used to calculate inflow rates of groundwater to each subsection of the tunnel. The study area is composed of section 1 and 2 of Imha-Youngchun waterway trnnel which has 32.976km length, with each section having 3,745m and 4,079m, respectively. The depth from groung surface to tunnel ranges from 122.45m to 358.3m. Total inflow rates of groundwater into each section measured three times by the current meter, together with bottle and eye measurement, were compared with groundwater inflow rates of each section measured by datalogger. The calcuated inflow rates of the sections by bottle and eye measurement were 8.8%∼54.7% of inflow rate (averaging 27,4%), whwewas those by the current meter were 76.9%∼110.6%(averaging 92.9%). Therfore, the current meter is regarded as useful method to calculate groundwater inflow rates into subsections of a tunnel.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 1999.06a
• /
• pp.125-131
• /
• 1999

In this paper, we address practical methods for calculating camera lens distortion for real time applications. Although the lens distortion problem can be easily ignored for constant-parameter lenses, in the field of real-time camera calibrations, for zoom lenses a large number of calculations are needed to calculate the distortion. However, if the distortion can be calculated independently of the other camera parameter, we can easily calibrate a camera without the need for a large number of calculations. Based on Tsai's camera model, we propose two different methods for calculating lens distortion. These methods are so simple and require so few calculations that the lens distortion can be rapidly calculated even in real-time applications. The first method is to refer to the focal length - lens distortion Look Up Table(LUT), which is constructed in the initialization process. The second method is to use the relationship between the feature points found in the image. Experiments were carried out for both methods, results of which show that the proposed methods are favorably comparable in performance with non-real full optimization method.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.602-603
• /
• 2007

In this paper, the RCF method is applied to analyze small signal stability of power systems including thyristor controlled FACTS equipments such as SVC. The eigenvalue sensitivity analysis algorithm in discrete systems by the RCF method are presented and applied to the power system including SVC. As a result of simulation, the RCF analysis method is very powerful to calculate the newly generated unstable oscillation modes precisely after periodic switching operations of SVC. Also the RCF analysis method enabled to precisely calculate eigenvalue sensitivity coefficients of dominant oscillation modes after periodic switching operations. These simulation results are very different from those of the conventional continuous system analysis method such as the state space equation method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2006.05a
• /
• pp.288-292
• /
• 2006

Usually, equations that calculate ground resistance of earth electrode was already informed well by form of earth electrode. But, when apply on the spot because general expressions are very insufficient at point that calculate exact ground resistance value by variation of earth electrode, and constant value that corrective coefficient for ground resistance calculation is fixed regardless of change of the earth resistivity specially is presented, it is actuality that difficulty is. Therefore, in this study, about these problem, proposed corrective coefficient for calculation of ground resistance according to change of the earth resistivity.