• 대한의용생체공학회:의공학회지
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• 제26권4호
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• pp.207-214
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• 2005

Breast cancer detection using electrical impedance techniques is based on numerous experimental findings that cancerous tissues have higher electrical conductivity values than normal tissues. Lately, by taking advantage of the structure of current flows underneath a planar probe of array electrodes, a mathematical formula to find lesions from a measured trans­admittance map has been derived. In order to experimentally validate its mathematical analysis and the suggested lesion estimation algorithm, we developed a 256-channel trans-admittance scanner (TAS) for probing anomalies underneath a planar array of electrodes. In this paper, we describe the design and implementation of the TAS. Its performance together with the lesion estimation algorithm was evaluated using saline phantoms. Further studies are proposed to validate the system on human subjects.

• 한국음향학회지
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• 제15권1호
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• pp.40-45
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• 1996

이 논문에서는 최적의 빔패턴을 얻기 위한 비선형 최적 설계 기법을 제시하였다. 제시된 방법을 사용하여 진동체 사이의 자기 및 상호 방사 임피던스를 고려하여 최대 허용 부엽준위가 주어진 경우 빔폭이 최소화된 빔 패턴을 설계할 수 있다. 그리고 37개의 진동체가 X, Y 및 $45^{circ}$축에 대칭으로 배열된 평면 배열에 대해 제안된 기법을 적용한 결과 빔폭은 변화없이 상당히 낮은 부엽 준위를 얻었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.993-994
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• 2007

This paper presents the normal force minimization design and the analysis of normal force effect which acts on the characteristics of the Synchronous Permanent Magnet Planar Motor (SPMPM) with new array. The experiments are applied to verify the analytical analysis. There is no doubt that the significant reduction of normal force and the experimental values dovetail nicely with the simulation.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1992년도 추계종합학술발표회 논문집
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• pp.323-326
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• 1992

• 한국음향학회지
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• 제15권1호
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• pp.17-22
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• 1996

소나 시스템에 주로 사용이 되는 평면 배열형 음향 트랜스듀서는 수중에서 음을 방사하여 빔(beam)을 형성하게 된다. 이러한 빔은 트랜스듀서 진동체에서 발생하는 음향 출력이 공간상에 분포되어 일어난다. 따라서 방사 출력의 산출은 트랜스듀서의 성능 및 효율을 예측하는데 필요하다. 본 논문에서는 무한 배플에 고정된 9개의 음향 진동체를 모델로 선정하였다. 개별 진동체에서의 음향 방사량은 자기방사 및 상호방사의 조합으로 표현이 되며 전기적 등가회로 기법을 이용하여 진동체 상호간의 음향 간섭 영향을 고려하여 평면 배열형 음향 트랜스듀서 진동체의 방사 출력 예측 기법을 제안 하였다.

• 한국군사과학기술학회지
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• 제21권1호
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• pp.61-68
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• 2018

In this paper, we described about methods and results to verify the Tx/Rx beam characteristics of a planar active phased array antenna as using a near-field measurement. The near-field system can effectively measure multiple beams and predict the performance degradation due to the partial failure of individual elements. Also, it can accurately predict the EIRP relating to detection performance of the active phased array radar. We briefly described the near-field measurement method to verify the Tx/Rx beam characteristics, and then verified the effectiveness of measurement method by analyzing the measured results.

• 전기전자학회논문지
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• 제26권1호
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• pp.129-132
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• 2022

본 논문에서는 위상배열안테나의 부엽레벨을 최소화할 수 있는 부배열 시스템 구조의 최적화에 관한 기술을 제안하였다. 제안된 배열안테나 구조의 최적화는 6개의 육각배열을 한 개의 부배열과 육각 부배열의 육각형 배열 구조를 이용하여, 부배열의 배열간격과 부배열 사이의 배열 간격을 조절하여, 전체 위상배열안테나 시스템의 방사패턴을 최적화하였다. 제안된 기술은 2차원 평명배열안테나 시스템에 비하여, 24.3 dBi의 이득과 8.46도의 반치각은 변화없이 유지하며, 오직 x축과 y축 방향으로 각각 -3.4 dB와 -6.5 dB를 감소시켰다.

• International Journal of Contents
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• 제6권2호
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• pp.6-9
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• 2010

Using symplectic relation and reaction concept, we propose a planar near-field antenna measurement method. A generalized probe compensation equation is deduced to obtain the probe correction formulation. To verify our approach, a reflector antenna with $1{\times}2$ horn array is fabricated and measured in the near-field measurement facility. The near-field measurement results are compared with the physical optics (PO) simulation. The results of measurement and simulation agree very well near to the mainbeam.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.1093-1097
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• 1995

A micro ion drag pump with planar electrodes on a glass substrate is fabricated and tested. the pump consisted of a 2- dimensional electrode pair array is driven by DC voltage using unipolar conduction. Ethy alcohol is pumped in both directions, and the flow rate and the pressure are measured, in channels of depth 100 .mu m or 200 .mu. m and width fixed at 3mm. It is found that the pump could be fabricated easily and at lower cost than the micro ion drag pumps previously investigated.

• 제어로봇시스템학회논문지
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• 제4권3호
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• pp.360-371
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• 1998

In this paper, output precision characteristics of a planar 6 degree-of-freedom parallel mechanisms are investigated, where the 6 degree-of-freedom mechanism is formed by adding an additional link along with an actuated joint in each serial subchain of the planar 3 degree-of-freedom parallel mechanism. Kinematic analysis for the parallel mechanism is performed, and its first-order kinematic characteristics are examined via kinematic isotropic index, maximum and minimum input-output velocity transmission ratios of the mechanisms. Based on this analysis, two types of planar 6 degrees-of-freedom parallel manipulators are selected. Then, dynamic characteristics of the two selected planar 6 degree-of-freedom parallel mechanisms, via Frobenius norms of inertia matrix and power modeling array, are investigated to compare the magnitudes of required control efforts of both three large actuators and three small actuators when the link lengths of three additional links are changed. It can be concluded from the analysis results that each of these two planar 6 degrees-of-freedom parallel mechanisms has an excellent control-in-the-small characteristics and therefore, it can be very effectively employed as a high-precision macro-micro manipulator when both its link lengths and locations of small and large actuators are properly chosen.