• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.356-359
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• 2000

In this paper, we propose a model based moving object tracking algorithm in dynamic scene. To adapt the shape change of the moving object, the Hausdorff distance is applied as the measurement of similarity between model and image. To reduce the processing time, 2-D logarithmic search method is applied for locate the position of moving object. Experiments on a running motorcycle, the result showed that the mean square error of real position and tracking result is 1.845 and consequently, matching process is relatively simple and reduced.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.3
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• pp.1-7
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• 1999

A single RF transceiver evaluation board have been developed for the purpose of application to the 900MHz band transceiver contained RF-IC chip And environment test was evaluated. The RF-IC chipset includes LNA(Low Noise Amplifier), down-conversion mixer, AGC(Automatic Gain Controller), switched capacitor filter and down sampling mixer. The RF evaluation board for the testing of chipset contained various external matching circuits, filters such as RF/IF SAW(Surface Acoustic Wave) filter and duplexer and power supply circuits. With the range of 2.7~3.3V the operated chip revealed moderate power consumption of 42mA. The chip was well operated at the receiving frequency of 925~960MHz. Measurement result is similar to general RF receiving specification of the 900MHz digital mobile phone.

• Journal of the Korea Computer Graphics Society
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• v.10 no.4
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• pp.27-36
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• 2004

본 논문에서는 뇌의 하부구조인 해마를 정확하게 분석하기 위한 형상 정규화 방법과 정상인과 간질 환자의 해마를 분류하기 위한 방법을 제시한다. 해마에 대한 형상 분석 과정은 크게 형상 표현을 구축하는 과정, 형상의 유사도를 측정하는 과정, 정상인 집단과 환자 집단을 분류하는 과정으로 이루어진다. 본 연구에서는 해마의 형상 표현으로 메쉬, 골격, 복셀로 이루어진 하이브리드 옥트리 자료구조를 구축하였다. 또한 Iterative Closest Point (ICP) 알고리즘을 사용하여 해마 골격을 기반으로 한 정규화를 수행하였다. 그리고 정규화된 해마 형상을 전역적, 국부적으로 분석하여 최종적으로 입력된 해마가 정상인 또는 간질 환자에 속하는지를 학습된 데이터를 이용하여 분류하였다. 본 논문에서 제시한 ICP 기반의 정규화 방법은 3차원 해마 형상을 정확하게 분석하게 해주고, 골격의 정점 수를 조절함으로써 정규화 시간을 감소시킬 수 있다. 뿐만 아니라 3차원 해마 모델의 형상을 신경망을 통하여 학습시킴으로써 해마의 형상이 변형된 환자 집단과 정상인 집단을 분류하는데 이용할 수 있다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.223-226
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• 2013

정확한 움직임 추정 기술은 원본과 가장 유사한 영상의 복원에 효과적이고 압축률에도 중요한 영향을 미친다. 하지만 기존의 전역 탐색 (Full Search) 알고리듬과 Sum of Absolute Difference (SAD)라는 정합 오차 기준은 연산량이 높고 하드웨어 구현시 비효율적이다. 이를 보완하기 위한 1비트 변환 알고리듬은 움직임 벡터의 변화량을 0과 1의 연산으로 나타내는데, 이 알고리듬은 움직임이 많아 픽셀 값의 변화가 심한 블록의 변화량도 0과 1로만 표현한다. 그렇기 때문에 정확한 움직임이 반영되지 않고 그로 인해 낮은 Peak Siganl to Noise Ratio (PSNR)을 가져온다. 이 점을 개선하고자 본 논문에서는 참조블록들의 움직임 벡터를 파악하고 분류하여 선택적으로 움직임의 변화량이 큰 영역은 전역 탐색 알고리듬을, 움직임이 작거나 없는 영역은 1비트 연산을 수행하도록 하여 기존의 알고리듬과 비교하여 Peak Siganl to Noise Ratio (PSNR)측면에서 우수한 성능을 확인할 수 있었다.

• Journal of Biomedical Engineering Research
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• v.19 no.3
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• pp.233-242
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• 1998

In anatomical aspects, magnetic resonance image offers more accurate information than other medical images such as X ray ultrasonic and CT images. This paper introduces a method that recognizes disk diseases from spine MR images. In this method, image enhancement, image segmentation and feature extraction for sagittal plane and axial plane images are performed to separate the disk region. And then template matching method is used to extract disease region for axial plane imges. Finally, disease feature vectors are integrated and disease discrimination processes are performed. Experimental results show that the proposed method discriminates between normal and diseased disk with a considerable recognition ratio.

• Journal of Broadcast Engineering
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• v.5 no.1
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• pp.41-49
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• 2000

In this paper, we propose a new method of indexing and searching based on object-specific features at different semantic levels for video retrieval. A moving trajectory model is used as an indexing key for accessing the individual object in the semantic level. By tracking individual objects with segmented data, we can generate motion trajectories and set model parameters using polynomial curve fitting. The proposed searching scheme supports various types of queries including query by example, query by sketch, and query on weighting parameters for event-based video retrieval. When retrieving the interested video clip, the system returns the best matching event in the similarity order.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.3
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• pp.79-87
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• 2000

In this paper, we propose a model based moving object tracking algorithm In dynamic scenes To adapt shape change of the moving object, the Hausdorff distance is applied as the measurement of similarity between model and image To reduce processing time, 2D logarithmic search method is applied for locate the position of moving object Experiments on a running vehicle and motorcycle, the result showed that the mean square error of real position and tracking result is 1150 and 1845; matching times are reduced average 1125times and 523 times than existing algorithm for vehicle image and motorcycle image, respectively It showed that the proposed algorithm could track the moving object accurately.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.4
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• pp.368-378
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• 2004

In this paper, we proposed the compensation structures for the enhanced directivity of CPW(Coplanar waveguide) directional couplers with finite-extent backed conductor. The proposed compensation structures are. realized by expanding the slot width between signal line and ground plane in center region of couplers. The CPW couplers with expanded slot have the same phase velocity for even and odd mode because of added inductance and changed capacitance appropriately, so the enhanced directivity is accomplished. The designed CPW directional couplers have good directivity and matching characteristic at center frequency in simulation and measurement.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.10 s.89
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• pp.915-921
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• 2004

In this paper, we propose a printed monopole antenna called the saw tooth monopole antenna(STMA) with a very wide band. And impedance matching of the antenna for the wideband is achieved using a special matching structure to vary ground size of back plate. The proposed antenna is smaller than general $\lambda$/4 monopole antenna in size but provides a 2:1 VSWR bandwidth of about $89.6\%$. The radiation pattern is omni-directional at 0.8 GHz$\~$2.0 GHz with gain of about -0.02 dBi$\~$2.54 dBi.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.8
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• pp.764-768
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• 2002

In this paper, a double balanced gilbert cell MMIC mixer was realized in Tachyonics SiGe HBT technology. The fabricated mixer has 17 dB conversion gain, 9.8 dB noise figure, -4.2 dBm output 1 dB compression point, -27 dBc RF to IF isolation, and the good input, output matching characteristics. It draws 10 mA from a 3 V supply. The simulation and the measured results are closer to each other, which confirms accuracy of the model library and reliability of the process.