• 전자공학회논문지A
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• 제32A권11호
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• pp.79-85
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• 1995

In this paper, an epi layer and a device structure for InP/InGaAs p-i-n/HBT OEIC is designed for a receiving frontend of high speed optical communications. A 3 stage transimpedance circuit using the p-i-n/HBT device is also designed by SPICE simulations for a high sensitivity including ISI noises at a given bit rate. Our simulations show that the Personick's assumption which is not commonly satisfied have estimated a photoreceiver sensitivity too high, so thus we have to also consider ISI noises in OCIC receiver designs.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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• pp.71-71
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• 2003

For fast MRI, the number of phase encoding steps has to be reduced. However, the reconstructed image is aliased if the phase encoding steps don't satisfy Nyquist sampling theory. SENSE is used in order to eliminate the aliasing effect as well as to reduce imaging time. SENSE is a linear algebraic technique applied to the multiple receiver data. In this study, we implement a tool to reconstruct the original image (SENSE image) with Sensitivity Encoding (SENSE)

• 대한기계학회논문집A
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• 제34권2호
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• pp.183-189
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• 2010

위치인식시스템은 이동로봇이 실내에서 주행하는데 가장 중요한 기술의 하나인데 본 논문에서 연구된 시스템은 GPS 시스템과 유사하게 3 개이상의 위성 비이컨에서 초음파와 무선통신파를 발사하고 로봇에 부착된 리시버는 초음파와 무선통신파의 수신되는 시간차를 계산하여 각 비컨까지의 거리를 구하고 또한 이로부터 로봇의 위치를 계산한다. 일반적으로 거리정보는 초음파의 한 파장 이내의 오차를 가지게 되는데 본 논문에서는 이에 따른 위치오차를 테일러 확장과 SVD(Singular Value Decomposition)를 이용하여 구하였다. 또한 본 논문에서는 거리오차에 따른 위치오차의 정확도를 잴 수 있는 값으로 민감도를 제시하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.363-368
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• 2014

Determination of the cause of malignant pleural effusions is important for treatment and management, especially in cases of unknown primaries. There are limited biomarkers available for prediction of the cause of malignant pleural effusion in clinical practice. Hence, we evaluated pleural levels of five tumor biomarkers (CEA, AFP, CA125, CA153 and CA199) in predicting the cause of malignant pleural effusion in a retrospective study. Kruskal-Wallis or Mann-Whitney U tests were carried out to compare levels of tumor markers in pleural effusion among different forms of neoplasia - lung squamous cell carcinoma, adenocarcinoma, or small cell carcinoma, mesothelioma, breast cancer, lymphoma/leukemia and miscellaneous. Receiver operator characteristic analysis was performed to evaluate sensitivity and specificity of biomarkers. The Kruskal-Wallis test showed significant differences in levels of pleural effusion CEA (P<0.01), AFP (P<0.01), CA153 (P<0.01) and CA199 (P<0.01), but not CA125 (P>0.05), among the seven groups. Receiver operator characteristic analysis showed that, compared with other four tumor markers, CA153 was the best biomarker in diagnosing malignant pleural effusions of lung adenocarcinoma (area under curve (AUC): 0.838 (95%confidence interval: 0.787, 0.888); cut-off value: 10.2U/ml; sensitivity: 73.2% (64.4-80.8)%, specificity: 85.2% (77.8-90.8)%), lung squamous cell carcinoma (AUC: 0.716 (0.652, 0.780); cut-off value: 14.2U/ml; sensitivity: 57.6% (50.7-64.3)%, specificity: 91.2% (76.3-98.0)%), and small-cell lung cancer (AUC: 0.812 (0.740, 0.884); cut-off value: 9.7U/ml; sensitivity: 61.5% (55.0-67.8)%, specificity: 94.1% (71.2-99.0)%); CEA was the best biomarker in diagnosing MPEs of mesothelioma (AUC: 0.726 (0.593, 0.858); cut-off value: 1.43ng/ml; sensitivity: 83.7% (78.3-88.2)%, specificity: 61.1% (35.8-82.6)%) and lymphoma/leukemia (AUC: 0.923 (0.872, 0.974); cut-off value: 1.71ng/ml; sensitivity: 82.8% (77.4-87.3)%, specificity: 92.3% (63.9-98.7)%). Thus CA153 and CEA appear to be good biomarkers in diagnosing different causes of malignant pleural effusion. Our findings implied that the two tumor markers may improve the diagnosis and treatment for effusions of unknown primaries.

• 한국광학회지
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• 제17권3호
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• pp.290-295
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• 2006

전기전도도가 높은 구리선 도파로에 THz 전자기파의 결합은 THz 유선방식의 전파에 있어 테라파의 크기 및 주파수 특성을 결정짓는 중요한 요인 중의 하나이다. 본 연구에서는 직경 $480{\mu}m$, 길이 23 cm의 구리선 도파로에 테라파를 전파시켜 1 THz 주파수 범위를 가진 THz 펄스를 측정하였다. 도파로와 transmitter chip 또는 receiver chip 사이의 공극 간격을 최대 $275{\mu}m$까지 확대하여 송신부와 수신부의 결합 특성을 접촉상태와 비교 분석하였다. 실험결과 송신부의 결합민감도가 수신부보다 약 3배 이상 높게 나타났으며 수신부에서 도파로와 receiver사이의 공극을 통하여 테라파가 공기 중으로 전파됨을 알 수 있었다. 또한 구리선 도파로에 pin hole를 위치시켜 pin hole의 직경에 따른 테라파의 변화를 연구하였으며 대부분의 THz field는 구리선 표면에 분포됨을 확인할 수 있었다.

• 제어로봇시스템학회논문지
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• 제14권7호
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• pp.695-701
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• 2008

In this paper, we propose the efficient Doppler removal method using map-based partial-time common intermediate frequency removal technique. In the proposed algorithm, the 2-stage carrier removal process was used. First, the component of common intermediate frequency is removed. Next the component of Doppler was removed with averaging and approximation. For the evaluation of the proposed algorithm, The real-time software GPS L1 C/A-code receiver was implemented. When the proposed algorithms are used, 12 tracking channels with 3 track arm(early, prompt, late) is operated real-time on PC using a Intel Pentium-III 1.0GHz CPU. Also, the requirement of memory was less than 2Mbytes. The real-time software GNSS receiver using the proposed algorithms provides the navigation solution with below 10 meter rms error. Especially, in spited of using the various approximations for implementing the algorithms, the high sensitivity capability (able to track the weak signal with -159dBm) was achieved.

• ETRI Journal
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• 제28권1호
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• pp.103-106
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• 2006

We have fabricated a planar lightwave circuit (PLC) hybrid-integrated optical sub-assembly of a triplexer using a thin film filter (TFF)-attached wavelength division multiplexer (WDM) and photodiode (PD) carriers. Two types of TFFs were attached to a diced side of a silica-terraced PLC platform, and the PD carriers with a $45^{\circ}$ mirror on which pin-PDs were bonded were assembled with the platform. A clear transmitter eye-pattern and minimum receiver sensitivity of -24.5 dBm were obtained under 1.25 Gb/s operation for digital applications, and a second-order inter-modulation distortion (IMD2) of -70 dBc was achieved for an analog receiver.

• 한국광학회지
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• 제5권2호
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• pp.333-339
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• 1994

단일모드 광섬유를 부착한 고속 광통신용 PIN-전치증폭기 모듈을 GaInAs PIN 광검출기와 GaAs 전치증폭기를 하이브리드로 집적하여 제작하였다. PIN 광검출기의 정전용량은 0.35pF이었으며 이 소자의 수광직경은 $20{\mu}m$였다. 제작된 수광모듈의 -3dB 차단주파수는 2GHz 이상이었으며 2.5Gbps NRZ$(PRBS=2^{23}-1)$ 입력광신호에 대해 비트오율이 $10^{-9}$일 때 -25.2dBm의 수신감도를 보였다.

• 한국정보통신학회논문지
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• 제13권6호
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• pp.1051-1057
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• 2009

교량감시, 문화재감시, 하천감시, 노약자보호, 도시관제 및 환경감시 등 많은 분야에서 USN(Ubiquitous Sensor Network)을 이용한 서비스가 시작되고 있고, USN을 구현하기 위해서는 RF 송수신기가 반드시 필요하다. 본 논문은 2.4GHz 대역에서 동작하는 센서노드용 RF 송수신기의 설계 및 제작에 대해서 기술한다. RF 송수신기의 설계과정으로 AGC의 범위 설정과 송수신기의 설계 과정이 기술되어 있다. 또한 설계된 RF 송수신기를 제작하여 성능을 시험하였으며, 수신감도, 동작범위, 주파수 안정도, 위상잡음, 송신전력, 송신대역평탄도와 스펙트럼 마스크의 측정 결과가 기술되어 있다.

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.875-880
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• 2018

This paper proposes a novel combined compensation structure in the infrared receiver chip. For the infrared communication chip, the current-voltage (I-V) convert circuit is crucial and important. The circuit is composed by the transimpedance amplifier (TIA) and the combined compensation structures. The TIA converts the incited photons into photocurrent. In order to amplify the photocurrent and avoid the saturation, the TIA uses the combined compensation circuit. This novel compensation structure has the low frequency compensation and high frequency compensation circuit. The low frequency compensation circuit rejects the low frequency photocurrent in the ambient light preventing the saturation. The high frequency compensation circuit raises the high frequency input impedance preserving the sensitivity to the signal of interest. This circuit was implemented in a $0.6{\mu}m$ BiCMOS process. Simulation of the proposed circuit is carried out in the Cadence software, with the 3V power supply, it achieves a low frequency photocurrent rejection and the gain keeps 109dB ranging from 10nA to $300{\mu}A$. The test result fits the simulation and all the results exploit the validity of the circuit.