• 대한핵의학회지
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• 제29권3호
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• pp.287-293
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• 1995

Anterior temporal lobectomy has become a widely used resective surgery in patients with medically intractable temporal lobe epilepsies. Prerequisites of this resection include the accurate localization of the epileptogenic focus and the determination that the proposed resection would not result in unacceptable postoperative memory or language deficits. The purpose of this study was to evaluate the performance of ictal SPECT compared to MRI findings for localization of epiletogenic foci in this group of patients. 11 patients who had been anterior temporal lobectomy were evaluated with ictal $^{99m}Tc$-HMPAO SPECT and MRI. MRI showed 8/11(73%) concordant lesion to the side of surgery and ictal SPECT also showed 8/11(73%) concordant hyperperfusion. In 3 cases with incorrect or nonlocalizing findings of MRI, ictal SPECT showed concordant hyperperfusion. In 2 cases confirmed by pre-resectional invasive EEG, MRI showed bilateral and contralateral lesion but ictal SPECT showed concordant hyperperfusion. 3 delayed injection of ictal SPECT showed discordant hyperperfusion. Thus, ictal SPECT was a useful method for localizing epileptogenic foci in temporal lobe epilepsis and appeared complementay to MRI.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
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• pp.419-427
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• 2000

The 4 by 4 microstrip phased array antenna designed and radiation characteristics are studied. The design frequency was chosen to be 5.8GHz. Chebyshev ratio was achieved by unequal power divider and Wilkinson power divider. The ratio of current at each port is 1 : 2.6 : 2.6 : 1 and then side lobe level is less than -30 dB. It is shown that the radiation beam direction can be changed up to 30。 by control the phase at each port. The result can be used to design electrically controllable microwave scanning antennas.

• Journal of Chest Surgery
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• 제17권3호
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• pp.470-474
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• 1984

33-year old female was admitted chest surgery department for evaluation of mild chest pain. Chest plain film showed right anterior mediastinal mass and small metastatic daughter mass ipsilateral side. Exploratory thoracotomy was performed 24th Aug. 83 revealed that small nodular parenchymal mass at right middle lobe and large cystic mass at anterior mediastinum which was connected with anterior mediastinal fat. Histological examination confirmed diagnosis as pulmonary hamartoma and thymic cyst individually. We successfully treated these two masses by wedge resection and excision. Although postoperative course was uneventful, the cause and associated relationship between two tumor origin were obscure.

• 대한전자공학회논문지
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• 제27권5호
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• pp.684-689
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• 1990

We design a circular microstrip array antenna using the admittance of circular resonator. We can design the array antenna, considering equivalent radius of circular microstdrip consistant with conductances which are obtained from excitation coefficeients of the array elements. The antenna with 10 array elements are made on teflon substrate from Tshebyscheff method. It's perfermence are the gain 8.9dB, half power beam width 11.3dge, max, side lobe level -19dB, and they are almost in agreement with the theoretical results.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.173-176
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• 1999

Frequency responses of the surface acoustic wave(SAW) filters are simulated by using the impulse modeling. The simulation technique of the SAW filters is to use the Fourier transformation to make a correspondence between the impulse response of the filter and the taps in the delay line. Since the Fourier series must be truncated after a finite number of terms, window functions are often used to weight the coefficients to obtain the desirable side-lobe level and bandwidth. The filter design is operated through the iterative simulation procedures. The design process is capable of yielding filters with optimized frequency response characteristics.

• 한국광학회:학술대회논문집
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• 한국광학회 2003년도 제14회 정기총회 및 03년 동계학술발표회
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• pp.318-319
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• 2003

이동통신 시스템에서 데이터, 음성, 영상신호를 효율적으로 전송하기 위해 위상 배열 안테나(Phased-Array Antenna： PAA)에 관한 연구가 최근 국내외적으로 활발히 진행되고 있다. 광통신 기술을 이용한 PAA용 실시간 지연선로 (True Time-Delay： TTD)는 넓은 대역폭, 저 손실, 전자파 간섭에 무관, 소형화, 특히 ‘beam squintr´ 현상이 없는 장점이 있기 때문에 각광을 받고 있다. 특히, 신호의 간섭을 줄이기 위해 안테나 방사 패턴의 부엽 (side lobe)의 크기를 감소시킬 수 있는 안테나 설계기술이 필요하다. (중략)

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권6호
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• pp.257-263
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• 2005

WDM optical communication system requires wavelength division multiplexing, reverse multiplexing and optical filter. OADM is a device that can separate or combine specific wavelength of channel from the transmission line. This paper suggests OADM that uses 2 steps FBG based on MZI structure. The OADM that uses 2 steps FBG can minimize the system size and reduce the value of side lobe remarkably. The results obtained in this paper can be used for design and application of OADM that uses 2 steps FBG.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.9-11
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• 2002

We improve the free-space optical interconnection efficiency by using circular aperture computer-generated hologram (CGH). In free-space optical interconnection system using CGH, the single CGH is composed of sub-CGHs, which can change the direction of input beams to desired output positions, by Fourier transform. Each sub-CGH is rectangular shape, so the input beams through each sub-CGH are transformed to sinc functions in output plane. The side lobes of each sinc function are superimposed in output plane and they result in detection error in output plane, so the detection efficiency is low. We use the circular shaped sub-CGHs in order to reduce the side lobe value in output plane instead of rectangular shaped sub-CGHs. The each input beam is transformed to first-order Bessel functions through circular shaped sub-CGHs in output plane. The side lobes of first-order Bessel functions us low values compared with side lobes of sinc function, so we can improve the detection efficiency in output plane. We use binary phase modulated CGH, and confirm this improvement results by simulation.

• 한국통신학회논문지
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• 제9권1호
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• pp.39-44
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• 1984

周邊端裝苛 拗物形 空中線과 水兵形 테두리附着 拗物形 空中線 및 후드附着形 拗物形 空中線等 세가지 形態의 拗物形 空中線을 同一條件下에서 製作하여 側葉 및 後葉特性을 比較하였다. 側葉 및 後葉의 抑制效果가 가장 優秀한 것은 후드 內部에 炭素粉末 混入 포리우레탄 스폰지를 內한 것을 附着한 것으로 E面上에서 側葉에 5내지 10dB, 그리고 後葉 15dB 效果를 얻었다.

• 한국전자파학회논문지
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• 제23권2호
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• pp.187-195
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• 2012

본 논문에서는 유전 알고리즘에 기반하여 선형 위상 배열 안테나에서 합성 빔의 부엽 세기를 최소화하기 위한 부배열 구조 최적화 기법을 제안한다. 부배열 구조의 최적 설계 시 부배열 구성에 적용이 가능하도록 유전 알고리즘의 연산을 수정하였다. 제안된 부배열 설계법을 이용하여 40개의 배열 소자를 갖는 선형 배열 안테나에서 합성 빔 및 재밍에 대한 적응 신호 처리 후의 부엽 세기를 최소로 하는 불규칙 구조의 16개로 구성된 부배열구조를 설계하였고, 규칙적인 부배열 구조에서의 최대 부엽 세기보다 약 10 dB 감소된 부엽 세기를 확인하였다.