• 한국산업정보학회논문지
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• 제18권1호
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• pp.11-17
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• 2013

A design method to achieve multiple band-rejection characteristics in a wideband circular slot antenna is presented. First, a wideband circular slot antenna fed by a coplanar waveguide is designed to operate in the frequency range between 2.3 and 11GHz, which covers WLAN, WiBro, WiMAX, and UWB frequency bands. Next, resonant frequency variations of rejection bands are examined with respect to different slot locations and lengths when slots are inserted on the ground conductor and the circular patch of the antenna. When arc-shaped slots are placed close to the circular transition from a feeding part, multiple notch bands are obtained. In this case, a half of the guided wavelength of the first notch band corresponds to the slot length and other notch bands are integer-multiple of the first band. Single notch band can be obtained when the slot is located off the transition part. Based on this study, a wideband circular slot antenna with five band-rejection frequency bands at 2.45, 3.5, 4.9, 7.35, and 9.8GHz is designed and fabricated. The first arc-shaped slots are located in the ground conductor close to the circular transition from a feeding part to generate notch bands at 2.45, 4.9, 7.35, and 9.8GHz, while the second slot for 3.73 GHz is placed on top side in the circular patch. The proposed design method is validated by good agreement between the simulated and measured results.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
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• pp.247-250
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• 2003

This paper proposed to digital watermarking technique for architectural drawing using LINES and ARCs based on vertex in CAD system to prevent infringement of copyright from unlawfulness reproductions and distribution. After extract LINES and ARCs from designed drawing, we embed watermarks using adaptive algorithm in each characteristics. Watermarks robust to various attacks like as geometrical transformation as being embedded in LINE's length and ARC's angle information. Also, the proposed method satisfies enough transparency about watermarked drawing because have suitable embedding strength to each component. By experimental result, we confirmed robustness and invisibility of embedded watermarks in several conversions of architectural design drawing.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제11B권2호
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• pp.22-27
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• 2001

Salient pole rotor type single phase switched reluctance motor is of simple and rigid structure, short shaft and simple driving circuit. Especially, the output power per unit volume of salient pole rotor structure is comparatively high because the magnetic fluxes of axial and radial direction are simultaneously used. Therefore, this motor will be used at small space and difficult maintenance situations. In this paper, the selecting method of proper pole arc, stator, and rotor dimension of salient pole rotor type single phase SRM is proposed.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제2B권4호
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• pp.156-161
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• 2002

This paper proposes an optimized universal motor for improving its performance using the finite element method (FEM) with the (1＋1) Evolution Strategy (ES) algorithm. To do this, various design parameters are modified, such as air gap length, shape of motor slot, pole shoe, pole width, and rotor shaft diameter. Two parameters (arc length of stator pole and thickness of pole shoe) are chosen and optimized using the program, and the optimized model is built and tested with a performance measuring system. The measured values of the model are compared with those of the initial and the optimized model to prove the algorithm. As a result, the final model improves its performance compared with those of the initial model.

• 한국구조물진단유지관리공학회 논문집
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• 제9권2호
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• pp.137-146
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• 2005

본 연구는 형상반복법과 수정 라그랑쥐 방법으로 사장교 케이블의 초기장력과 기준길이를 계산하였다. 사장교의 거더와 주탑은 3차원 frame 요소로, 케이블은 비선형 트러스요소와 Ernst의 케이블 요소로 이상화하였다. 본 연구의 유한요소법에 의한 케이블의 초기장력과 실무에서 사용하는 시산법에 의한 케이블의 장력을 비교한 결과, 전자의 경우가 후자의 경우보다 적음을 알 수 있었다. 케이블의 기준길이는 비선형 트러스요소를 사용한 해석결과와 Ernst의 케이블 요소를 사용한 해석결과를 비교하였으며 두 가지 해석결과가 거의 일치함을 알 수 있었다. 또한 기준길이는 초기장력값을 나타내는 단순교의 지간과 거의 일치함을 알 수 있었다. 따라서 케이블의 기준 길이는 본 연구로부터 얻은 초기장력을 가진 단순보의 호의 길이를 나타냄을 알 수 있었다.

• Journal of Welding and Joining
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• 제34권1호
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• pp.54-58
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• 2016

In this research paper, suggest method of generate same bead as an actual measurement data in virtual welding conditions, exploit morphology information of the bead that acquired through robot welding. It has many multiple risk factors to Beginners welding training, by we make possible to train welding in virtual reality, we can reduce welding training risk and welding material to exploit bead visualization algorithm that we suggest so it will be expected to achieve educational, environmental and economical effect. The proposed method is acquire data to each case performing robot welding by set the voltage, current, working angle, process angle, speed and arc length of welding condition value. As Welding condition value is most important thing in decide bead form, we would selected one of baseline each item and then acquired metal followed another factors change. Welding type is FCAW, SMAW and TIG. When welding trainee perform the training, it's difficult to save all of changed information into database likewise working angle, process angle, speed and arc length. So not saving data into database are applying the method to infer the form of bead using a neural network algorithm. The way of bead's visualization is applying the spline algorithm. To accurately represent Morphological information of the bead, requires much of morphological information, so it can occur problem to save into database that is why we using the spline algorithm. By applying the spline algorithm, it can make simplified data and generate accurate bead shape. Through the research paper, the shape of bead generated by the virtual reality was able to improve the accuracy when compared using the form of bead generated by the robot welding to using the morphological information of the bead generated through the robot welding. By express the accurate shape of bead and so can reduce the difference of the actual welding training and virtual welding, it was confirmed that it can be performed safety and high effective virtual welding education.

• Communications for Statistical Applications and Methods
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• 제15권5호
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• pp.775-781
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• 2008

It is developed that a family of the semicircular Laplace distributions for modeling semicircular data by simple projection method. Mathematically it is simple to simulate observations from a semicircular Laplace distribution. We extend it to the l-axial Laplace distribution by a simple transformation for modeling any arc of arbitrary length. Similarly we develop the l-axial log-Laplace distribution based on the log-Laplace distribution. A bivariate version of l-axial Laplace distribution is also developed.