• 대한전자공학회논문지
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• 제22권1호
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• pp.53-60
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• 1985

A computer vision system for robot is developed which can recognize a variety of two dimensional complex objects in gray level noisy scenes. the system is also capable of determining the position and orientation of the objects for robotlc manipulation. The hardware of the vision system is developed and a new edge tracking technique is also proposed. The linked edges are approximated to sample line drawing by split and merge algorithm. The system extracts many features from line drawing and constructs relational structure by the concave and convex hull of objects. In matching process, the input obhects are compared with the objects database which is formed by learning ability. Thelearning process is so simple that the system is very flexible. Several examples arc shown to demonstrate the usefulness of this system.

• 한국IT서비스학회지
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• 제14권2호
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• pp.143-158
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• 2015

Companies and governments in an era of big data have been tried to create new values with their data resources. Among many data resources, many companies especially pay attention to data which is obtained from Social Network Service (SNS) because it reveals precise opinion of customers and can be used to estimate profiles of them from their social relationships. However, it is not only hard to collect, store, and analyze the data, but system applications are also insufficient. Therefore, this study proposes a S-POS (Social POS) system which consists of three parts; Twitter Side, POS Side and TPAS (Twitter&POS Analysis System). In this system, SNS data and POS data which are collected from Twitter Side and POS Side are stored in Mongo D/B. And it provides several services with POS terminal based on analysis and matching results which are generated from TPAS. Through S-POS system, we expect to efficient and effective store and sales managements of system users. Moreover, they can provide some differentiated services such as cross-selling and personalized recommendation services.

• 대한전자공학회논문지SD
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• 제43권7호
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• pp.13-19
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• 2006

5Gb/s대역 크로스커플 구조의 트랜스임피던스 증폭기 및 제한증폭기가 연결된 광 수신기를 광 PCB에 응용하기 위해 설계 하였다. 회로는 0.18um CMOS 공정으로 구현되었다. 광 수신기는 0.5pF 광 다이오드 기생 캐퍼시턴스에서 $92.8db{\Omega}$ 임피던스 이득과 5Gbps의 주파수 대역을 갖는다. 그리고 1.8V, 2.4V 공급전압에서 9.74mV의 전력소모를 보인다. 입력단의 임피던스는 $50{\Omega}$ 이다. 회로를 광 PCB기판에 올려 광신호 송신 실험하여 5Gb/s 데이터의 수신을 확인하였다.

• ETRI Journal
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• 제36권2호
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• pp.214-223
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• 2014

A fully-integrated penta-band reconfigurable power amplifier (PA) is developed for handset Tx applications. The output structure of the proposed PA is composed of the fixed output matching network, power and frequency reconfigurable networks, and post-PA distribution switches. In this work, a new reconfiguration technique is proposed for a specific band requiring power and frequency reconfiguration simultaneously. The design parameters for the proposed reconfiguration are newly derived and applied to the PA. To reduce the module size, the switches of reconfigurable output networks and post-PA switches are integrated into a single IC using a $0.18{\mu}m$ silicon-on-insulator CMOS process, and a compact size of $5mm{\times}5mm$ is thus achieved. The fabricated W-CDMA PA module shows adjacent channel leakage ratios better than -39 dBc up to the rated linear power and power-added efficiencies of higher than around 38% at the maximum linear output power over all the bands. Efficiency degradation is limited to 2.5% to 3% compared to the single-band reference PA.

• Journal of electromagnetic engineering and science
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• 제17권4호
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• pp.178-180
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• 2017

This study presents a 2-20 GHz monolithic distributed power amplifier (DPA) using a $0.25{\mu}m$ AlGaN/GaN on SiC high electron mobility transistor (HEMT) technology. The gate width of the HEMT was selected after considering the input capacitance of the unit cell that guarantees decade bandwidth. To achieve high output power using small transistors, a 12-stage DPA was designed with a non-uniform drain line impedance to provide optimal output power matching. The maximum operating frequency of the proposed DPA is above 20 GHz, which is higher than those of other DPAs manufactured with the same gate-length process. The measured output power and power-added efficiency of the DPA monolithic microwave integrated circuit (MMIC) are 35.3-38.6 dBm and 11.4%-31%, respectively, for 2-20 GHz.

• 한국통신학회논문지
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• 제10권2호
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• pp.69-75
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• 1985

印章識別은 平滑化, 回轉 및 移動, 細線化整合技法의 순서로 수행된다. CCTV카메라에 入力된 印章映像은 A/D變換機와 8bit microcomputer에 의하여 $256{\times}256$畵素의 2進映像으로 변환한다. 두 映像을 定位置로 回轉시킨 후, 細線化過程을 거쳐 文字의 골격선을 찾는다. 畵素거리에 따라 Weight.를 정하고 distance-weighted Correlation, C를 계산한다. 계산된 $C^K$와 결정상수 $C_YES$, $C_NO$를 비교하여 印章을 識別한 결과 95%의 높은 識別率을 얻었고 한 개의 對象印章을 識別하는데 걸린 시간은 3분 이내였다.

• 센서학회지
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• 제14권2호
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• pp.116-124
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• 2005

In this paper range measurement systems are designed using an ultrasonic sensor and a camera. An ultrasonic sensor provides the range measurement to a target quickly and simply but its low resolution is a disadvantage. We tackle this problem by employing a camera. Instead using a stereoscopic sensor, which is widely used for 3D sensing but requires a computationally intensive stereo matching, the range is measured by focusing and structured lighting. In focusing a straightforward focusing measure named as MMDH(min-max difference in histogram) is proposed and compared with existing techniques. In the method of structure lighting, light stripes projected by a beam projector are used. Compared to those using a laser beam projector, the designed system can be constructed easily in a low-budget. The system equation is derived by analysing the sensor geometry. A sensing scenario using the systems designed is in two steps. First, when better accuracy is required, measurements by ultrasonic sensing and focusing of a camera are fused by MLE(maximum likelihood estimation). Second, when the target is in a range of particular interest, a range map of the target scene is obtained by using structured lighting technique. The systems designed showed measurement accuracy up to 0.3[mm] approximately in experiments.

• Journal of Plant Biotechnology
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• 제47권4호
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• pp.273-282
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• 2020

In Vietnam, Celastrus hindsii Benth, a medicinal plant rich in secondary metabolites, has been used to alleviate distress caused by ulcers, tumors, and inflammation for generations. The occurrence of two phenotypes, Broad Leaf (BL) and Narrow Leaf (NL), has raised questions about the selection of appropriate varieties for conservation and crop improvement to enhance medicinal properties. This study examined molecular differences in C. hindsii by comparing protein profiles between the NL and BL types using 2D-PAGE and MS. Peptide sequences and proteins were identified by matching MS data against the MSPnr100 databases and verified using the MultiIdent tool on ExPASy and the Blast2GO software. Our results revealed notable variations in protein abundance between the NL and BL proteomes. Selected proteins were confidently identified from 12 protein spots, thereby highlighting the molecular variation between NL and BL proteomes. Upregulated proteins in BL were found to be associated with flavonoid and amino acid biosynthesis as well as nuclease metabolism, which probably attributed to the intraspecific variations. Several bioactive proteins identified in this study can have applications in cancer therapeutics. Therefore, the BL phenotype characterized by healthier external morphological features has higher levels of bioactive compounds and could be better suited for medicinal use.

• 대한기계학회논문집B
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• 제34권12호
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• pp.1087-1092
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• 2010

단일카메라 기반의 마이크로 스테레오 PTV 측정시스템을 구축하였다. 단일의 카메라에 부착되는 마이크로 대물렌즈 후부에 2 개의 핀을 가진 얇은 원판을 설치하여 한 장의 영상에 스테레오 영상을 얻을 수 있었다. 스테레오 영상간의 동일한 입자영상을 대응시키기 위하여(matching) 반복계산 기반의 PTV 알고리듬을 구축하였다. 계산시간을 줄이기 위하여 에피폴라선을 이용하였으며 스테레오 영상으로부터 얻어진 동일입자들의 3 차원 위치정보(X, Y, Z)의 시간 이동량을 계산함으로써 3 차원 속도벡터를 구하였다. 측정시스템은 광원레이저(Ar-ion, 500mW), 1 대 카메라($1028{\times}1024$ pixel, 500fps), 2 개의 핀홀을 지닌 원판 및 호스트컴퓨터로 구성된다. 가상영상을 이용하여 2 개의 핀홀 간격과 핀홀 직경의 크기변화에 대한 측정알고리듬의 오차와 속도벡터 회복률 특성을 구하였다. 구축된 시스템을 마이크로후향단채널($H{\times}h{\times}W:\;36{\mu}m{\times}70{\mu}m{\times} 3000{\mu}m$) 유동의 측정에 적용하여 얻어진 결과를 수치계산 결과와의 비교로부터 정성적으로 일치한 결과를 얻었다.

• 한국자기학회지
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• 제15권2호
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• pp.67-75
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• 2005

경량 전파흡수체 구현 방안의 하나로 저밀도(약 0.2g/cc) 중공미세구 표면에 수 ${\cal}um$ 두께의 Co 피막을 무전해 도금에 의해 코팅하고, 고주파 전자기 특성 및 전파흡수특성을 조사하였다. Co 도금은 활성화 처리와 도금공정 2단계 과정을 거쳐 시행되었다. 도금공정의 반복에 의해 두께 $2{\~}3\mu$m의 균일한 Co 피막을 얻을 수 있었다. 이 분말을 실리콘 고무와 혼합하여 복합체를 제조하고, 고주파 전자기 물성 및 전파흡수특성을 회로망 분석기로 측정하였다. Co 피막의 강자성 특성 및 전도 특성에 의해 높은 자기손실 및 유전상수를 얻을 수 있었다. 이와 같은 전자기적 특성에 의해 GHz 대역에서 우수한 전파흡수특성(두께 2.0$\~$2.5mm, 전파흡수능 20dB 이상)이 확인되었다. 특히 Co 도금 중공미세구의 밀도(0.84 g/cc)는 페라이트(5.0 g/cc)에 비해 약 1/6에 불과하기 때문에 경량 전파흡수체로서 응용가치가 매우 높음을 제시할 수 있었다.