• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1996년도 춘계학술대회
• /
• pp.31-35
• /
• 1996

This paper presents a real time algorithm for monitoring of the arrythmia of ECG signal. A real time monitoring, following by detecting a QRS complex, is the most important. Using 2-dimensional time-delay coordinates which are reconstructed by the phase portrait plotting special trajectory, we detect QRS complexes. In this study, arrythmias are detected by matching the past standard template with tile present pattern when changing abruptly In order to matching with each other, we propose modified chain coding algorithm which applies vetor table consisting of eight orthonormal code(=binary code) to the phase portraits. This algorithm using logical function increases the weight if exceeding to the threshold determinded by correlation value and the distance from a straight line(y=x). Evaluating the performance of the proposed algorithm, we use standard MIT/BIH database. The results are fellowing, 1) Improve the speed of matching template than that of cross-correlation ever has been used. 2) Because the proposed algorithm is robust to varing fiducial point, it is possible to monitor the ECG signal with irregular RR interval. 3) In spite of baseline wandering owing to the low frequency noise, monitoring performance is not reduced.

• 한국콘텐츠학회논문지
• /
• 제15권9호
• /
• pp.411-417
• /
• 2015

Liver CT 검사에서 간세포암과 간혈관종의 구별은 악성종양과 양성종양을 구별하여 치료방법을 결정하는 것에 있어서 중요한 검사 방법 중 하나이다. 현재 사용되는 방법은 전문의의 주관적인 해석에 의해 판독이 이루어지고 있으며, 추가적인 해석을 위해 본 연구에서는 객관적인 방법을 제시하고자 한다. 조영제 주입 후 검사시간은 조영주입전기(Pre), 동맥기(35sec), 문맥기(70sec), 지연기(180sec)로 하였다. 조영증강패턴변화(Enhancement Pattern) 에서 간세포암의 일반적인 패턴변화는 26.6% 로 관찰 되었다. 간혈관종의 일반적인 패턴변화는 16.6%로 관찰 되었다. 간세포암과 간혈관종의 HU(Hounsfield unit)값 변화를 관찰하기 위해 각각의 시간별 평균값과 표준편차를 확인한 결과 Lesion부위의 artery-portal차이가 가장 큰 것으로 나타났다. (간세포암 $19.76{\pm}23.52$, 간혈관종 $60.23{\pm}29.43$). 간세포암 에서 76.6%, 간혈관종 에서 80.0%가 일치하게 나타났다. 본 연구를 통해 HCC와 HH의 객관적 분석 지표로 HU값 을 제안하고 분석방법을 임상에 사용 한다면 진단에 도움을 줄 것이다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 추계종합학술대회 논문집
• /
• pp.179-182
• /
• 1998

Carrier recovery, the process of recoverying the carrier in receiver, removes the phase difference between VCO and the received signal. However, the conventional structure of carrier recovery cannot be applied to multi-level QAM demodulator because of the increasing decision interval and the complexity of control as the number of symbol increases. In this paper, we suggest a new carrier recovery algorithm using $\theta-matching$ algorithm for multi-level QAM demodulation to overcome this problem and analysis the performance and implement it.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.1844-1845
• /
• 2007

A CUSUM control chart was used to monitor semiconductor plasma equipment. The performance of plasma monitoring was evaluated with various combinations of design variables involved in CUCUM control chart. Experimental data collected by using a real-time matching monitoring system include electrical positions of impedance and phase positions, and reflected power. The evaluation revealed that by determining specific design variables plasma states could be more strictly monitored.

• 전자공학회논문지A
• /
• 제32A권2호
• /
• pp.96-110
• /
• 1995

Traveling-wave electrodes for the high-speed Ti:LiNbO$_{3}$ modulators are designed. For a solution to the problems of 1) phase-velocity mismatching between the optical wave and the Modulating M/W, 2) M/W electrode characteristic impedance mismateching, we assume devices with 1$\mu$m thick SiO$_{2}$ buffer layer between the electrode and the Ti:LiNbO$_{3}$ substrate. The electrode analyses are performed by the FEM using the second-order triangular elements. The optimum design parameters to satisfy the phase-velocity matching and the characteristic impedance matching are sought for. By use of the analyses' results, a Mach-Zehnder optical modulator with a CPW electrode is designed as an example. the band-width estimation is also illustrated.

• 한국정밀공학회지
• /
• 제25권9호
• /
• pp.116-125
• /
• 2008

Inkjet printing technology with a drop-on-demand (DOD) inkget head technology has been recognized as one of versatile and low cost manufacturing tools in the electronics industry. Concerned with control of driving signal, however, general strategy to optimize jetting stability has not been understood well, because of the inherent complex multi-physics nature in inkjet phenomena. Motivated by this, present study investigates the effect of driving waveforms of piezoelectric head on jetting characteristics of DOD inkjet system focused on jetting stability with phase matching of pressure waves in the print head. The results show that velocities and volumes of the ink jetted droplets were linear relations with the driving signal's maximum voltage, while periodic behaviors are observed with the driving signal's pulse widths.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.1444-1449
• /
• 2007

Inkjet printing technology with a drop-on-demand (DOD) inkjet head technology has been recognized as one of versatile and low cost manufacturing tools in the electronics industry. Concerned with control of driving signal, however, general strategy to optimize jetting stability has not been understood well, because of the inherent complex multi-physics nature in inkjet phenomena. Motivated by this, present study investigates the effect of driving waveforms of piezoelectric head on jetting characteristics of DOD inkjet system focused on jetting stability with phase matching of pressure waves in the print head. The results show that velocities and volumes of the ink jetted droplets were linear relations with the driving signal's maximum voltage, while periodic behaviors are observed with the driving signal's pulse widths.

• Current Optics and Photonics
• /
• 제4권1호
• /
• pp.63-68
• /
• 2020

We built an optical parametric oscillator (OPO) generating orthogonally polarized signals at different wavelengths simultaneously, based on a periodically poled lithium niobate (PPLN) crystal. The OPO was pumped by ns-pulses at 1.064 ㎛ from a diode-pumped solid-state laser, where we found the type-0 and the type-1 quasi-phase matching conditions were satisfied simultaneously in the PPLN crystal. This enabled us to create a coherent light source which can emit dual signals which could be accessed easily by rotating a polarizer.

• 전자공학회논문지A
• /
• 제29A권8호
• /
• pp.41-48
• /
• 1992

The characteristics of traveling-wave electrodes for high-frequency electroptic integrated devices are described from the view point of improvement of phase-matching based on the conformal mapping method. Specific calculations of the characteristic impedance, effective microwave index, and eletrode loss for asymmetric coplanar strip(ACPS) and coplanar waveguide(CPW) electrode structures are presented as a function of the geometric electrode parameters including the electrode thickness and buffer layer thickness. 5-10(x10S0-6Tm) thick Au-ACPS electrodes were successfully fabricated by electroplating and ECR etcher. The improvement of modulation bandwidth can be theoretically observed from the combination of electrode and buffer layer thickness.

• Journal of Electrical Engineering and Technology
• /
• 제13권2호
• /
• pp.998-1007
• /
• 2018

The advent of Wireless Sensor Networks (WSN) has led to their use in numerous applications. Sensors are autonomous in nature and are constrained by limited resources. Designing an autonomous topology with criteria for economic and energy conservation is considered a major goal in WSN. The proposed honey-hive clustering consumes minimum energy and resources with minimal transmission delay compared to the existing approaches. The honey-hive approach consists of two phases. The first phase is an Intra-Cluster Min-Max Discrepancy (ICMMD) analysis, which is based on the local honey-hive data gathering technique and the second phase is Inter-Cluster Frequency Matching (ICFM), which is based on the global optimal data aggregation. The proposed data aggregation mechanism increases the optimal connectivity range of the sensor node to a considerable degree for inter-cluster and intra-cluster coverage with an improved optimal energy conservation.