• ETRI Journal
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• 제35권4호
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• pp.697-705
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• 2013

Emerging trends in the area of digital very large scale integration (VLSI) signal processing can lead to a reduction in the cost of the cochlear implant. Digital signal processing algorithms are repetitively used in speech processors for filtering and encoding operations. The critical paths in these algorithms limit the performance of the speech processors. These algorithms must be transformed to accommodate processors designed to be high speed and have less area and low power. This can be realized by basing the design of the auditory filter banks for the processors on digital VLSI signal processing concepts. By applying a folding algorithm to the second-order digital gammatone filter (GTF), the number of multipliers is reduced from five to one and the number of adders is reduced from three to one, without changing the characteristics of the filter. Folded second-order filter sections are cascaded with three similar structures to realize the eighth-order digital GTF whose response is a close match to the human cochlea response. The silicon area is reduced from twenty to four multipliers and from twelve to four adders by using the folding architecture.

• ETRI Journal
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• 제26권6호
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• pp.545-554
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• 2004

In this paper, we propose an efficient design method for area optimization in a digital filter. The conventional methods to reduce the number of adders in a filter have the problem of a long critical path delay caused by the deep logic depth of the filter due to adder sharing. Furthermore, there is such a disadvantage that they use the transposed direct form (TDF) filter which needs more registers than those of the direct form (DF) filter. In this paper, we present a hybrid structure of a TDF and DF based on the flattened coefficients method so that it can reduce the number of flip-flops and full-adders without additional critical path delay. We also propose a resource sharing method and sharing-pattern searching algorithm to reduce the number of adders without deepening the logic depth. Simulation results show that the proposed structure can save the number of adders and registers by 22 and 26%, respectively, compared to the best one used in the past.

• 한국컴퓨터정보학회논문지
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• 제25권7호
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• pp.57-64
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• 2020

본 논문에서는 상관필터를 이용한 영상 추적에서 탐색 영역의 크기 조절이 가능한 재탐지 방법을 제안한다. 실제 장비를 통해 영상 추적 기능을 실행할 때에는 표적이 특정 물체에 가리고 다시 나타나는 일이 빈번하게 일어나는데, 따라서 표적의 소실 판단과 재탐지 방법이 필요하다. 본 알고리즘은 강인한 추적을 위해 커널 상관필터를 사용한다. 일반적인 상관필터를 활용한 영상 추적 알고리즘에서는 표적을 탐지하는 범위가 학습된 필터의 크기에 국한된다. 하지만 표적의 가림이 오랜 시간 지속될수록 표적의 위치는 예측된 위치에서 벗어날 가능성이 커지고, 따라서 충분히 큰 범위에서 표적의 탐색이 이루어져야 한다. 제안하는 방법은 매 프레임 2%씩 탐색 범위를 넓히며 재탐지를 시도하여 성공률을 높인다. 실험은 항공에서 촬영된 4가지 영상을 활용하였고, 제안한 알고리즘은 재탐지가 어려운 데이터셋에서도 성공적인 결과를 보였다.

• 대한전자공학회논문지SD
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• 제37권10호
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• pp.73-81
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• 2000

본 논문은 분할된 look up table(LUT) 구조를 갖는 전력 소모 및 면적에 효율적인 보간 저역통과 여파기의 설계에 관한 것이다. 제안한 보간 여파기는 계수 대칭성과 LUT 데이터들이 대칭성을 이용하여 면적이 최소화된다. 최소의 면적으로 위상에 따라 분할된 LUT는 두개의 여파기가 공유하고 선택적으로 활성화됨으로써 저 전력 동작을 수행한다. 제안된 여파기는 5.0V 0.6${\mu}m$ CMOS 공정으로 설계되었으며 전력 소모 시뮬레이션은 Powermill을 사용하여 수행하였다. 기존에 제안된 여파기들과의 비교 실험 결과를 통하여 제안한 필터의 전력 소모는 26% 감소하였고 게이트 면적은 5% 감소하였음을 보인다.

• 한국산업보건학회지
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• 제25권4호
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• pp.542-553
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• 2015

Objectives: Many types of dust collector are used for industrial ventilation, with the most common types being the cylinder bag filter system, rectangular bag filter system and cylinder type cartridge filter system. The cylinder type cartridge bag filter, which has more filtering area than other types of bag filter, can increase the pulse time and extend the useful life of the filter. This can save operational costs and installation area. Materials: This study used cylinder type cartridge bag filter equipment and tested the impact of vibration level and filter pressure with different pulse jet cleaning conditions. The final, cleaning efficiency was calculated through input dust mass and cleaning dust mass Conclusions: Two optimum cleaning condition groups were found. The first condition group was $3kgf/cm^2$ pulse pressure, 15 cm pulse distance, 0.2 s pulse time with an H-10 type nozzle. The second condition group was $3kgf/cm^2$ pulse pressure, 15 cm pulse distance, 0.3 s pulse time with an H-10 type nozzle.

• Carbon letters
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• 제10권3호
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• pp.198-201
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• 2009

Among other filters such as light filter, wave filter, air filter, ultra filter and filter paper, a novel adsorption filter from thermostable polyester nonwoven fabrics immobilized with functional super activated carbon by means of quinoline soluble, activateable isotropic pitch binder were developed in this study. The activated carbon precursor is available in the market branded as coconut shell based activated carbon(CCS-AC) produced by Dongyang Carbon Co. Ltd. BET-surface area of this precursor was $1,355\;m^2/g$, after KOH-activation it increased over $2,970\;m^2/g$ and was named as super activated carbon. In the preliminary research, this precursor was impregnated with $PdCl_2$(0.188 wt%) $KMnO_4$(3 wt%) and redox-agent(CuCl2, 0.577 wt%) in order to promote TOF up to 100/h and Selectivity up 99% and patented as a functional AC for the ethylene adsorption. The enhancement of the isotropic pitch binder to the AC-immobilized adsorption filter was BET-surface area upgraded by $266\;m^2/g$ and promoted the Iodine- and MB-adsorption by 1.4 times, respectively and also micro pore wide ranges < $5{\AA}{\sim}30\;{\AA}$ >.

• 한국지구과학회지
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• 제38권2호
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• pp.105-114
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• 2017

Two dimensional finite element method with quadrilateral basis functions was applied to the spherical high order filter on the spherical surface limited area domain. The basis function consists of four shape functions which are defined on separate four grid boxes sharing the same gridpoint. With the basis functions, the first order derivative was expressed as an algebraic equation associated with nine point stencil. As the theory depicts, the convergence rate of the error for the spherical Laplacian operator was found to be fourth order, while it was the second order for the spherical Laplacian operator. The accuracy of the new high order filter was shown to be almost the same as those of Fourier finite element high order filter. The two-dimension finite element high order filter was incorporated in the weather research and forecasting (WRF) model as a hyper viscosity. The effect of the high order filter was compared with the built-in viscosity scheme of the WRF model. It was revealed that the high order filter performed better than the built in viscosity scheme did in providing a sharper cutoff of small scale disturbances without affecting the large scale field. Simulation of the tropical cyclone track and intensity with the high order filter showed a forecast performance comparable to the built in viscosity scheme. However, the predicted amount and spatial distribution of the rainfall for the simulation with the high order filter was closer to the observed values than the case of built in viscosity scheme.

• 응용통계연구
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• 제16권2호
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• pp.239-246
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• 2003

소지역에서 직접(direct) 시계열추정을 할 수 있다면, 소지역들 추정에서 최적선형 불편 예측량(BLUP)을 일반화 시킬 수 있다. 특히 조사에서 얻어지는 관측 값의 오차가 시간상으로 상관관계가 있다면 Kalman Filter(KF)기법이 사용 될 수 있다. 이 연구는 예측 값을 활용한 소지역의 실업자 수 추정에서 표본으로 추출되지 않은, 즉 관측되지 않은 값의 예측모형에 KF기법을 적용하였다. 이는 경제활동인구수를 이용하여 현 시점의 소지역 실업자 수를 예측함수(BLUP)를 통해 추정하게 된다. 그리고 이를 단순 회귀분석 추정치와 비교하였다.

• 한국지능시스템학회논문지
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• 제19권4호
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• pp.586-591
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• 2009

본 논문에서는 Particle filter를 이용한 특징 벡터 기반 이동 물체 추적 알고리즘을 제안한다. 이를 위해, 첫 번째, RGB 칼라 모델을 이용하여 초기 이동 물체의 움직임 영역(blob)을 추출하고, KLT-알고리즘을 이용하여 입력 영상에 대한 특징 벡터를 구한다. 그 다음, 초기 추출된 이동 물체의 움직임 영역에 이 특징 벡터를 매칭시켜 1차 특징 벡터를 구한다. 두 번째로, RGB와 HSI 칼라모델을 이용하여 이동 물체의 움직임 영역을 추출하고, 앞서 구한 1차 특징 벡터에 Snake 알고리즘을 적용함으로써 새로운 특징 벡터를 구한다. 그 다음, 기 추출된 이동 물체의 움직임 영역에 이 새롭게 구한 특징 벡터를 매칭시켜 2차 특징 벡터를 구한다. 최종적으로, 2차 특징 벡터에 Particle filter를 적용함으로써 본 논문에서 제안한 이동물체를 추적하는 알고리즘을 완성한다. 마지막으로, 본 논문에서 제안한 알고리즘은 복잡하고 다양한 환경에서 실험을 통해 그 응용 가능성을 증명한다.

• 반도체디스플레이기술학회지
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• 제21권4호
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• pp.33-38
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• 2022

With an attempt to suppress the moiré phenomenon caused by the interference between the black matrix of a display panel and the metal grid of a camera, we have fabricated an anti-moiré filter using light diffusing particles (LDPs) with the average diameter of 20 ㎛. It is demonstrated that the anti-moiré filter coated on a glass substrate (370 mm × 470 mm) using a table slot-die coater reduces the moiré intensity to a great extent when the area covered by LDPs is 50%. To quantify the intensity of moiré phenomenon, we have measured the lightness ratio and found that it is reduced from 132.12 down to 105.71 by the filter. To find the optimum area covered by LDPs, we have performed ray tracing simulations using Mie scatters as a substitute for LDPs. From the simulated irradiation distribution, we have calculated the standard deviation (SD) and contrast ratio (CR) to evaluate the moiré strength. As expected, the SD and CR values decrease with increasing covered area by LDPs. However, there exists a trade-off between the transmittance of the filter and its capability of reducing the moiré intensity in determining the area covered by LDPs.