• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
• /
• pp.172-177
• /
• 1988

In this paper, a new fast algorithm of FIR least squares filter with linear phase is presented. The general unknown statistics case is considered, whereby only sample records of the data are available. Taking advantage of the near-to-Toeplitz+Hankel structure of the resulting normal equation, a fast algorithm which gurantees the linear phase constraint, is developed that recursively produces the filter coefficient of linear phase FIR filter for a single block of data.

• 한국광학회:학술대회논문집
• /
• 한국광학회 1991년도 제6회 파동 및 레이저 학술발표회 Prodeedings of 6th Conference on Waves and Lasers
• /
• pp.177-180
• /
• 1991

본 연구는 광 패턴 인식을 위한 사진 위상 필터(QPOG)를 분석하였다. 사진 위상 필터를 이용하여 광 패턴 인식을 한 경우 특정한 패턴에 대해서는 판별력이 뛰어나지만 한 패턴이 다른 패턴의 부분 패턴이 되면 판별력이 떨어짐을 알 수 있었다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
• /
• pp.1445-1448
• /
• 1987

The phase-only filter (POF) to the classical matched filter is compared for the criteria of discrimination, correlation peak, and optical efficiency in Korean alphabet. In addition, logarithmically scaled POF is presented to improve the recognition efficiency and this shows the superior performances in English alpanumeric characters to Korean.

• 대한전자공학회논문지
• /
• 제26권12호
• /
• pp.2046-2054
• /
• 1989

Improved algorithms are presented to design linear phase digital FIR filters with coefficients of +1,0,-1 only followed by a multiple integrator. It has been shown that the existing linear phase filter design concept for the single integrator(or, accumulator)case can be extended to the case of the multiple integrator. Linear phase conditions for the multiple integrators are summarized. Filter design methods with double or triple integrator are exploited in datail and its computer simulation results are presented to deduce the advantages of multiple integrator to the single integrator.

• 전자공학회논문지D
• /
• 제34D권6호
• /
• pp.65-74
• /
• 1997

In this paper, SA-multiplexed filter is designed using SA (simulated ananealing) to recognize music notation patterns varying in size, shape, position and having considerably many similar shapes for optical pattern recognition system. This filter has correlation resutls at wanted location and can identify same class, classify similar class for scale-varianted or rotation-varianted music notation patterns havng learning process. Also, the optimum filter is oriented to analyze on the similar discrimination at acquired position using SA and enhances optical diffractive efficiency as well as peak beam intensity. Compared with POF *(phase only filter), cosine-BPOF(cosine-binary phase only filter), that has excellent discrimination capability even if the different rate is 0.1% quantitatively.

• 대한전자공학회논문지
• /
• 제26권8호
• /
• pp.1262-1269
• /
• 1989

For the efficient recognition of Korean characters, a modified ternary phase-only synthetic discriminanty function filter(MTPOF-SDF) is proposed. MTPOF-SDF can not only discriminate the true class patterns and the similar, symmetric, or patially included false ones but also recognize the diverse variations in true class patterns due to combinatorial form as the same ones. And scale and rotation-invariant recognition is achieved. To preserve the features of the characters, phase information should be used. And to contsrol phase information easily, ternary quantization of the phase is preferred. Also low resolution requirement is achieved for compatibility with low resulution devices such as spatial light modulators.

• 한국방송∙미디어공학회:학술대회논문집
• /
• 한국방송공학회 2009년도 IWAIT
• /
• pp.450-455
• /
• 2009

Amplitude-only logarithmic Radon transform (ALR transform) for pattern matching is proposed. This method provides robustness for object translation, scaling, and rotation. An ALR image is invariant even if objects are translated in a picture. For the object scaling and rotation, the ALR image is merely translated. The objects are identified using a phase-only matched filter to the ALR image. The ratio of size, the difference of rotation angle, and the position between the two objects are detected. Our pattern matching procedure is described, herein, and its simulation is executed. We compare matching scores with the Fourier-Mellin transform, and the general phase-only matched filter.

• Journal of the Optical Society of Korea
• /
• 제20권1호
• /
• pp.101-106
• /
• 2016

A pupil filter is a useful technique for modifying the light intensity distribution near the focus of an optical system to realize depth of field (DOF) extension and superresolution. In this paper, we proposed a new design of the phase only pupil filter by using Zernike polynomials. The effect of design parameters of the new filters on DOF extension and superresolution are discussed, such as defocus Strehl ratio (S.R.), superresolution factor (G) and relative first side lobe intensity (M). In comparison with the other two types of pupil filters, the proposed filter presents its advantages on controlling both the axial and radial light intensity distribution. Finally, defocused imaging simulations are carried out to further demonstrate the effectiveness and superiority of the proposed pupil filter on DOF extension and superresolution in an optical imaging system.

• 한국통신학회논문지
• /
• 제29권6C호
• /
• pp.777-784
• /
• 2004

이 논문에서는 CIC(Cascaded Integrator-Comb) 필터와 half band 필터를 직렬로 연결하여 사용하는 데시메이션 필터의 주파수 응답을 향상시키는 보간 필터를 제안한다. 기존의 방식들은 통과대역의 리플 특성만을 향상시키나, 이 논문에서는 통과대역의 특성과 저지대역의 감쇠특성을 동시에 향상시키는 IFOP(Interpolated Fourth-Order Polynomials) 필터를 제안한다. 설계 방법도 저지대역을 특성향상을 완료한 후에 통과대역 특성을 향상시키므로 최적화 프로그램을 사용하지 않고도 체계적으로 설계가 가능함을 보였다. 제안된 필터는 곱셈이 2개 필요한 구조이므로 부가적인 연산량이 적으며, 또한 선형위상의 특성을 갖고 있으므로 선형위상 특성을 그대로 유지할 수 있다. 예제들을 통하여 저지대역과 통과대역의 특성이 향상되는 양을 관찰하였으며, Verilog-HDL coding을 통하여 계수 양자화 영향도 분석하였다.

• 한국철도학회논문집
• /
• 제7권4호
• /
• pp.339-344
• /
• 2004

This paper proposes transformerless power conversion system consisting of a single-phase diode rectifier and a shunt hybrid filter for the electric-railway system. The hybrid filter consists of a single tuned LC filter per a phase and a low-rated NPC type multi-level inverter. Compared with conventional active filters. transformers are not used. Also, LC filter works as not only a harmonic filter tuned at the 3rd harmonic frequency but also a switching-ripple filter. The rating of the active filter can be decreased by using a NPC type multi-level inverter. The simulation results confirm the validity of the system.