• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.545-548
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• 2002

This paper proposes a unidirectional beam antenna using a probe excited circular ring near the reflector. The antenna structure is simple. The radiation characteristics of the antenna fur various spacing between a probe excited circular ring and the reflector are analyzed. These characteristics are also compared with the conventional single aperture near the reflector. It is found that the proposed structure yields better characteristics than the conventional structure. The numerical results of the radiation pattern, elevational beam peak, beamwidth, and maximum directivity are investigated. The result of the analysis is very useful to design the antenna of the high directivity with unidirectional beam.

• 한국기계가공학회지
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• 제20권7호
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• pp.25-32
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• 2021

In the previous study, a study was conducted to improve the exhaust gas intake efficiency by improving the existing soot measurement probe in the shape and angle of the exhaust port. As a result, it can be seen that the smoke measurement performance according to the shape and angle is improved. In previous studies, the performance of the soot probe was not confirmed for the Korean KD 147 mode, which has a low suction flow rate and a long inspection time. So, we would like to confirm the improvement of the smoke probe performance of the Korean KD 147 mode, which is close to the actual driving conditions. The probe used in this study is another type of probe, and has a circular ring shape instead of a rib and variable center position unit, so the probe center hole is located close to the center of the exhaust pipe.

• 한국공작기계학회논문집
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• 제11권2호
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• pp.24-29
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• 2002

A study for the circularity of machine tool is classified into two ways. One is to measure the circularity of machine tool by a existing measuring device. The other is to measure the circularity by remodeling the existing measuring device. We will improve on measurement of circularity using circular test method by a two-dimensional probe and a master ring for machining tools and investigate influence of trigger method, acceleration data sampling.

• 한국정밀공학회지
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• 제10권2호
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• pp.54-65
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• 1993

The paper describes and alternative method based on a new idea to measure the circular movement of machining centers. ISO has employed three testing methods for the acceptance tests of machine tools; the first is a rotating one-dimensional probe method, the second is a two-dimensional probe and a master circular ring, and the third is a kinematic ball bar. The last two methods were proposed and introduced by W. Knapp and J. B. Bryan, respectively. The newly developed method is superior to above two methods; the rotating angle can be detected and the rotating radius is variable. Circular movement errors of machining centers were investigated by the analysis of data measured by R- .THETA. method. Followint observations are obtained 1) The errors which depend on positions, i.e., periodical errors by the pitch of ball screws, errors by compensation of backlash and errors by perpendicularity of X and Y-axis, were analyzed. 2) The errors which depend on NC control system, i.e., errors by the unbalance of position-loop-gaians, errors by velocity-loop-gains and errors by feed speeds, were quantiatively analyzed. 3) The method of extracting error information, which uses moving technique of averaging angle and fourier's analysis data mesured by the R- .THETA. method, was proposed.

• 한국정밀공학회지
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• 제13권3호
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• pp.56-62
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• 1996

This paper presented a new measuring system to improve circular motion accuracy by using two-dimensonal probe and master ring for NC machine tools. This measuring system reduced the circular motion error conspicuously by eliminating the influence of the acceleration/deceleration range and compensating the friction force whose influences were significant while measuring the motion. Experimental results show that this system had enough accuracy to measure a circular motion for NC machine tools, compared with the circular test method and the r .theta. method.

• 정보통신설비학회논문지
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• 제2권1호
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• pp.13-21
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• 2003

This paper presents the analysis of the mode characteristics of an annular ring microstrip patch antenna for circular polarization with attachment mode using method of moments in the spectral domain. For a probe excitation, the input impedance are obtained by using the single mode approximation for both the $TM_{11}$ and $TM_{12}$ modes and compared with those by Vector Hankel Transform. While the $TM_{11}$ mode has a high Q, it is a poor radiating mode; the $TM_{12}$ mode is more suitable for antenna applications. It is also shown that the bandwidth of the $TM_{12}$ mode is wider than that of the $TM_{11}$ mode in terms of axial ratio for circular polarizatio

• E2M - 전기 전자와 첨단 소재
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• 제11권11호
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• pp.17-21
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• 1998

The surface potential distribution on insulating polymers was measured by scanning of the probe of an electrostatic voltmeter. The measurements were done for two measured by scanning of the probe of an electrostatis voltmeter. The measurements were done for two cases. In the first case, it was measured on the free surface of insulating films which had been inserted between plane electodes after the removal of the upper brass disk electrode. In the second case, we measured the charging region between a circular and its opposing concentric ring electrodes after the removal of dc ramp voltage in air and nitrogen gas.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.719-722
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• 2002

This paper reports the characteristics of a bidirectional antenna by using a planar array of a probe excited circular ring. The element of a bidirectional antenna is first designed to achieve the maximum directivity. The directivity can be further increased by arranging these elements to form the linear array. There are two types of linear array to be investigated i.e., on axis and off axis arrangement. On-axis linear array yields better directivity than off-axis linear array. Therefore, this orientation is further used to form the planar array. The radiation characteristics of this optimum planar array are rigorously reported. The proposed structure is very useful to extend the distance between the base station in PCT system.

• 전자공학회논문지
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• 제50권10호
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• pp.41-49
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• 2013

본 논문에서는 차량 충돌 방지용 밀리미터파 레이더 시스템용 안테나에 적용 가능한 LTCC(low temperature co-fired ceramic) 공정을 사용한 유전체 공진기 안테나(DRA, dielectric resonator antenna)를 제안한다. 76-77 GHz에서 공진하는 DRA를 설계하며, LTCC 공정을 사용하여 유전체 공진기 내부에 SRR(split ring resonator)을 넣은 구조와 모노폴을 넣은 구조를 제안한다. 또한 모노폴을 넣은 구조는 선형 편파를 제공하는 안테나와 원형편파를 제공하는 두 가지 구조로 설계한다. 유전체 공진기 내부 구조 및 편파, 급전 마이크로스트립 선로 길이 및 마이크로스트립 구조에 따라 총 3가지 모델의 DRA를 설계하고, EM 해석 소프트웨어인 CST를 사용하여 각 안테나의 반사손실 특성 및 방사 패턴을 계산한다. 설계된 안테나를 실제 제작하여 특성을 측정하고 계산치와 비교한다. 제작된 DRA 측정결과 원하는 대역인 76-77GHz 대역에서 공진 특성을 나타내고, 8.15 dBi에서 10.82 dBi의 안테나 이득을 획득하였다.

• 전자공학회논문지SC
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• 제47권5호
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• pp.52-61
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• 2010

최근 피부의 마찰계수를 이용하여 한의학에서의 체질을 구별하는 연구가 활발히 이루어지고 있다. 피부의 마찰계수는 여러 고문헌에서도 알려져 있듯이 태음인과 소양인의 체질을 구별하는 인자로 활용되고 있다. 본 연구에서는 다축 로드셀과 일정하중식 접촉 프로브를 이용하여 피부의 마찰계수를 정량적으로 측정하는 장비를 개발하였고 이의 측정 불확도를 측정하였다. 개발된 장비의 상대 반복도는 2 %였다. 태음인과 소양인의 체질진단 구분을 위해 왼속 손등을 측정부위로 선택하여 실험한 결과 약지를 따라 측정하는 것이 가장 효과적임을 알 수 있었다. 20명의 피험자를 대상으로 임상측정을 한 결과, 개발된 장비의 경우 3 % 이내의 측정 불확도를 가지고 태음인과 소양인의 체질 구분을 할 수 있었다.