• 대한전자공학회논문지
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• 제21권2호
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• pp.29-35
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• 1984

LMS(least mean Square) 알고리즘은 그 간편성에 의하여 적응 필터의 대표적인 알고리즘으로 되고 있다. 본 논문에서는 잘 알려진 1차원 LMS 원응 필터를 2차원 필터로 광장시킬 수 있음을 보였으며, 필터의 목산 속도 양선방안 및 2차원 적응 필터에서 발생하는 몇 가지 문제점들에 관하여 고찰하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.49-52
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• 1999

In this paper, we describe the structure of the DWMT (discrete wavelet multitone) transceiver for VDSL system. The DWMT transceiver is basically consisted of the transmultiplexer using cosine modulation filter bank (CMFB), time domain equalizer (TEQ) and frequency domain equalizer (FEQ) minimizing the effects of the transmission channel. For FEQ, we expanded the general LMS algorithm to 2-dimensions: time and subchannel axes and examined the 2-dimensional LMS methods with the various array size.

• 전자공학회논문지 IE
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• 제45권2호
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• pp.20-27
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• 2008

본 논문에서는 TFT-LCD 편광필름의 결함을 검출하기 위한 새로운 영상처리기법을 제안한다. 레이저 반사광을 이용하여 획득한 편광필름 영상에서 우선 배경잡음을 제거하기 위하여 형태론적 영상처리기법(열림, 닫힘)을 사용한다. 배경잡음이 제거된 영상으로부터 결함을 검출하기 위하여 2차원 LMS 적응 예측기를 사용하여 밝은 결함을 검출하고 통계적 특성을 이용하여 어두운 결함을 검출한다. 산업현장에서 제공된 TFT-LCD 편광필름을 사용하여 제안된 기법의 성능을 평가한다.

• 한국통신학회논문지
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• 제25권4B호
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• pp.629-634
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• 2000

본 논문에서는 VSDL 시스템을 위한 discrete wavelet multitone (DWMT) 송수신기의 구조에 대해 기술한다. DWMT 송수신기는 코사인 변조 필터 뱅크를 사용한 트랜스 멀티플렉서, 전송 채널의 영향을 최소화하기 위한 시간 영역 등화기 및 주파수 영역 등화기 등으로 구성된다. 주파수 영역 등화기를 위해 기존의 1차원 선형 등화기법을 시간 및 부채널 축의 2차원으로 확장하여 2차원 LMS 방법으로 구현하였다. 등화기 평가 계수를 DWMT 기반 VDSL 송수신기에 적용하여 ANSI T1E1.4의 VDSL 전송 시험 선로 규격을 사용한 모의실험을 통해 성능을 확인하였다.

• 통합자연과학논문집
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• 제2권2호
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• pp.69-72
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• 2009

Pentiptycenediacetylene is very useful precursor materials for the synthesis of conducting polymer materials. The incorporation of rigid three-dimensional pentiptycene moieties into conjugated polymer backbones would offer several design advantages. They prevent ${\pi}$-stacking of the polymer backbones and thereby maintain high fluorescence quantum yields and spectroscopic stability in thin films. The pentiptycenediactylene was synthesized and characterized by 1H- and 13C-NMR spectroscopy.

• 한국통신학회논문지
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• 제21권9호
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• pp.2317-2327
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• 1996

Original binary image can be reconstructed without any distortion by MS(morphological skeleton) image. Though we reduce some points in a MS image, there is no problem to reconstruct original image by it. And then, there are two methods of LMS and GMS which reduce the redundant points of a MS image. The redundancy degree of a GMS image is zero and it is less than that of LMS. And then, GMS image is the best thing of the three kinds of morphological skeleton image to enhance the compression efficienty by the Elias code. But there are continous SKF=1 points in a GMS image whenever using 2 dimensional structureing element. Those points in a GMS image gives rise to a bad compression efficiency. And then, solving this problem, this paper proposes hybrid structuring elements algorithms for binary image compression.

• 전기학회논문지
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• 제58권11호
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• pp.2299-2301
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• 2009

The adaptive IIR filters for active noise control systems are more effective when acoustic feedback exists, but the adaptive IIR filters could be unstable when the filter algorithm is not yet converged. In this paper, auto-secondary path estimation techniques and a stabilizing process for adaptive Multi-Channel Recursive LMS (MCRLMS) filters are developed to improve the stability of multi-channel active noise control systems. Experiments using a TMS320VC33 digital signal processor in a three dimensional enclosure have performed to show the effectiveness of the proposed algorithm.

• 한국군사과학기술학회지
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• 제15권1호
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• pp.1-8
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• 2012

Obstacle detection is much studied by using sensors such as laser, vision, radar and ultrasonic in path planning for UGV(Unmanned Ground Vehicle), but not much reported about its characterization. In this paper not only an obstacle classification method using 2-dimensional LMS(Laser Measurement System) but also a decision making method whether to avoid or traverse the obstacle is proposed. The basic idea of decision making is to classify the characteristics by 2D laser scanned data and intensity data. Roughness features are obtained by range data using a simple linear regression model. The standard deviations of roughness and intensity data are used as measures for decision making by comparing with those of reference data. The obstacle classification and decision making for the UGV can facilitate a short path to the target position and the survivability of the robot.

• Journal of information and communication convergence engineering
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• 제7권3호
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• pp.392-398
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• 2009

A novel approach is presented to improve the array performance of the alternate mainbeam nulling in a linearly constrained adaptive array processor in coherent environment. The convergence parameters in the linearly constrained LMS algorithm with a unit gain constraint and a null constraint in the direction of the desired signal are adaptively estimated to reduce the error power between the desired signal and the array output in the 2-dimensional convergence parameter space. It is shown that the case for estimating the convergence parameter for the unit gain constraint with that for null constraint fixed performs best. Also, it is observed that the proposed method performs significantly better than conventional methods as the number of coherent interferences increases.

• Journal of Korean Neurosurgical Society
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• 제50권3호
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• pp.166-172
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• 2011

Objective : The intralaminar screw (ILS) fixation technique offers an alternative to pedicle screw (PS) and lateral mass screw (LMS) fixation in the C7 spine. Although cadaveric studies have described the anatomy of the pedicles, laminae, and lateral masses at C7, 3-dimensional computed tomography (CT) imaging is the modality of choice for pre-surgical planning. In this study, the goal was to determine the anatomical parameter and optimal screw trajectory for ILS placement at C7, and to compare this information to PS and LMS placement in the C7 spine as determined by CT evaluation. Methods : A total of 120 patients (60 men and 60 women) with an average age of $51.7{\pm}13.6$ years were selected by retrospective review of a trauma registry database over a 2-year period. Patients were included in the study if they were older than 15 years of age, had standardized axial bone-window CT imaging at C7, and had no evidence of spinal trauma. For each lamina and pedicle, width (outer cortical and inner cancellous), maximal screw length, and optimal screw trajectory were measured, and the maximal screw length of the lateral mass were measured using m-view 5.4 software. Statistical analysis was performed using Student's t-test. Results : At C7, the maximal PS length was significantly greater than the ILS and LMS length (PS, $33.9{\pm}3.1$ mm; ILS, $30.8{\pm}3.1$ mm; LMS, $10.6{\pm}1.3$; p<0.01). When the outer cortical and inner cancellous width was compared between the pedicle and lamina, the mean pedicle outer cortical width at C7 was wider than the lamina by an average of 0.6 mm (pedicle, $6.8{\pm}1.2$ mm; lamina, $6.2{\pm}1.2$ mm; p<0.01). At C7, 95.8% of the laminae measured accepted a 4.0-mm screw with a 1.0 mm of clearance, compared with 99.2% of pedicle. Of the laminae measured, 99.2% accepted a 3.5-mm screw with a 1.0 mm clearance, compared with 100% of the pedicle. When the outer cortical and inner cancellous height was compared between pedicle and lamina, the mean lamina outer cortical height at C7 was wider than the pedicle by an average of 9.9 mm (lamina, $18.6{\pm}2.0$ mm; pedicle, $8.7{\pm}1.3$ mm; p<0.01). The ideal screw trajectory at C7 was also measured ($47.8{\pm}4.8^{\circ}$ for ILS and $35.1{\pm}8.1^{\circ}$ for PS). Conclusion : Although pedicle screw fixation is the most ideal instrumentation method for C7 fixation with respect to length and cortical diameter, anatomical aspect of C7 lamina is affordable to place screw. Therefore, the C7 intralaminar screw could be an alternative fixation technique with few anatomic limitations in the cases when C7 pedicle screw fixation is not favorable. However, anatomical variations in the length and width must be considered when placing an intralaminar or pedicle screw at C7.