• Journal of Advanced Marine Engineering and Technology
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• v.28 no.4
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• pp.611-617
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• 2004

Pixel classification is one of basic image processing issues. The general characteristics of the pixels belonging to various classes are discussed and the radical principles of pixel classification are given. At the same time. a pixel classification scheme based on image direction measure is proposed. As a typical application instance of pixel classification, an adaptive multi-level median filter is presented. An image can be classified into two types of areas by using the direction information measure, that is. smooth area and edge area. Single direction multi-level median filter is used in smooth area. and multi-direction multi-level median filter is taken in the other type of area. What's more. an adaptive mechanism is proposed to adjust the type of the filters and the size of filter window. As a result. we get a better trade-off between preserving details and noise filtering.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.11
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• pp.85-95
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• 2000

FIR digital filter is one of important blocks in DSP application. For more effective operation, lots of architecture are proposed. In our paper, we proposed a high speed FIR filter with area efficiency. To fast operation, we used transposed form filter as basic architecute. And, we used dual path registers line to wupport variation of filter operation, and filter cascade is also considered. To reduce area, we adopted truncated Booth multiplier to our filter design. As a result, we showed that filter area is reduced when filter optimization using of dual path registers line and truncated multiplier with same constraints againt previous method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.5
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• pp.1005-1009
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• 2010

This paper presents a digitally-controlled filter calibration technique for biquad RC filter using self oscillation. The biquad RC filter is converted to a fully-differential ring oscillator by changing its resistor connections, where the oscillation frequency reflects the cut-off frequency. The proposed calibration circuit measures the oscillation frequency by counting with a fixed higher-frequency clock and then tunes it to a desired frequency with a digital frequency-locked loop including a PI controller. Because the proposed circuit directly measures the cut-off frequency of the filter itself and calibrates it with the small area digital circuits, the area and the power consumption are much small compared with conventional works. When it is implemented in a 65nm CMOS process, the calibration circuit except the filter consumes the area of 80um X 50um and power consumption is 443uA at 1.2 V supply voltage.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.71-76
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• 2021

Digital decimation filters are used in various digital signal processing systems using ADCs, including digital communication systems and sensor network systems. When the sampling rate of digital data is reduced, aliasing occurs. So, an anti-aliasing filter is necessary to suppress aliasing before down-sampling the data. Since the anti-aliasing filter has to have a sharp transition band between the passband and the stopband, the order of the filter is very high. However, as the order of the filter increases, the complexity and area of the filter increase, and more power is consumed. Therefore, in this paper, we propose two types of decimation filters, focusing on reducing the area of the hardware. In both cases, the complexity of the circuit is reduced by applying the required down-sampling rate in two times instead of at once. In addition, CIC decimation filters without a multiplier are used as the decimation filter of the first stage. The second stage is implemented using a CIC filter and a down sampler with an anti-aliasing filter, respectively. It is designed with Verilog-HDL and its function and implementation are validated using ModelSim and Quartus, respectively.

• Korean Journal of Digital Imaging in Medicine
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• v.14 no.2
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• pp.47-56
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• 2012

Amount of radiation exposure by seeing through fluoroscopy examination while is many patient exposure administration and unprepared misgovernment be. In this study, abdominal fluoroscopy during the scan, the dose and image quality change according to the use of grid and added filter optimized by measuring the test condition is proposed. Uses seeing through fluoroscopy examination equipment of Image Intensifier of Easy Diagnost Eleva (Philips), under tube type and uses Human phantom and measures average area dose according to grid insertion existence and nonexistence and added filter kind change. Measure sum of 29 organ dose and effective dose through PCXMC imagination simulation program and image J program through noise, SNR, image distortion was measured. Resolution, sharpness, and analyzed using the MTF curves. Fluorography the grid to insert the filter thickness and thickening and increased the average area dose and organ doses and effective dose. In the case of spot examination, when inserted grid, average area dose and organ dose and effective dose increased. Filter thickens the average area dose decreased, but the organ doses and effective dose were increased when use 0.2mmCu+1mmAl filter, decreased slightly. Noise and SNR measurements without inserting the gird, if you do not use the added filter was the lowest and when measure the distortion, 0.1mmCu+1mmAl filter was no difference of image quality in case insert grid was judged that when did not use occasion added filter that do not use grid, difference of image quality does not exist. Did not show a big difference, according to the grid and uses of the added filter sharpness, and resolution. Patient dose increases with factors that reduce the quality of the image so reckless grid and the use of the added filter when abdominal fluoroscopy examination should be cautious in using.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.2
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• pp.205-209
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• 1998

This study was conducted to evaluate the effect of triacetin(TA) treatment during manufacturing carbon dual filter for the adsorption of cigarette smoke components by activated carbons. The measurements were carried out by separation of activated carbon from carbon dual filter, and the specific surface area analyzed. The specific surface area of activated carbon from the domestic cigarette filter and from the foreign cigarette filter by degassing at 9$0^{\circ}C$ was 163$\pm$32$m^2$/g, and 16.6$\pm$1.9$m^2$/g, respectively. Those values were very lower than that of degassing at 35$0^{\circ}C$ (Domestic brand: 952$\pm$30$m^2$/g, and Foreign brand: 847$\pm$73$m^2$/g). By comparing the adsorption capacity of acetone and benzene with and without triacetin treated activated carbon, there was a 20% reduction of adsorption capacity by 5% triacetin treatment. Also, from the cilia toxicity test with carbon dual filter treated 0 % TA and 8 % TA, the cilia survival time was 706$\pm$74sec. and 603$\pm$64sec. for 0% TA and 8% TA, respectively. The delivery rate of vapour phase of cigarette smoke, which consists of main components of cilia toxicity, was higher at 8% TA filter than 0 % TA filter. Our results indicate that the treated TA covered the micro-pore of activated carbon, and then reduced specific surface area, finally, decreased the adsorption of vapour phase from cigarette smoke.

• Journal of Korean Society on Water Environment
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• v.30 no.2
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• pp.159-165
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• 2014

Vegetative Filter Strip (VFS) is one of effective Best Management Practices (BMPs) to prevent sediment-laden water problem, is installed at the edge of source area such agricultural area so that sediment occurred in source area is trapped by VFS before it flow into stream or river. Appropriate scale of it needs to be simulated before it is installed, considering various field conditions. In this study, a model using VFSMOD-w model and Genetic Algorithm to determine effective VFS length was developed, it is available to calibrate input parameter related to source area sediment yield through thousands of VFSMOD-w simulations. Useful DBs, moreover, are stored in the model so that very specific input parameters can be used with reasonable values. Compared simulated values to observed data values for calibration, R2 and Nash-Stucliffe model efficiency coefficient were 0.74 and 0.65 in flow comparison, and 0.89 and 0.79 in sediment comparison. The model determined 1.0 m of Filter Length, 0.18 of Filter Slope, and 0.2 cm of Filter Media Spacing to reduce 80% of sediment by VFS. The model has not only Auto-Calibration module also DBs for specific input parameters, thus, the model is expected to be used for effective VFS scale.

• Journal of the Korea Society of Computer and Information
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• v.22 no.7
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• pp.47-54
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• 2017

Recently, correlation filter based trackers have shown excellent tracking performance and computational efficiency. In order to enhance tracking performance in the correlation filter based tracker, search area which is image patch for finding target must include target. In this paper, two methods to discriminatively represent target in the search area are proposed. Firstly, search area location is estimated using pyramidal Lucas-Kanade algorithm. By estimating search area location before filtering, fast motion target can be included in the search area. Secondly, we investigate multi-channel Local Edge Pattern(LEP) which is insensitive to illumination and noise variation. Qualitative and quantitative experiments are performed with eight dataset, which includes ground truth. In comparison with method without search area estimation, our approach retain tracking for the fast motion target. Additionally, the proposed multi-channel LEP improves discriminative performance compare to existing features.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.387-388
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• 2010

There is no generalized and systematic method yet to data pre-processing for point cloud data classification even if there have been lots of previous studies such as local maxima filter, morphology filter, slope based filter and so on. Main focus of this study is to present classification method for bare ground information from LiDAR data for the mountainous area.

• International Journal of Control, Automation, and Systems
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• v.1 no.3
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• pp.390-394
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• 2003

To classify the significant wavelet coefficients into edge area and noise area, a morphological clustering filter applied to wavelet shrinkage is introduced. New methods for wavelet shrinkage using morphological clustering filter are used in noise removal, and the performance is evaluated under various noise conditions.