• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3490-3507
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• 2014

License plate detection (LPD) is one of the most important aspects of an automatic license plate recognition system. Although there have been some successful license plate recognition (LPR) methods in past decades, it is still a challenging problem because of the diversity of plate formats and outdoor illumination conditions in image acquisition. Because the accurate detection of license plates under different conditions directly affects overall recognition system accuracy, different methods have been developed for LPD systems. In this paper, we propose a license plate detection method that is rapid and robust against variation, especially variations in illumination conditions. Taking the aspects of accuracy and speed into consideration, the proposed system consists of two stages. For each stage, Haar-like features are used to compute and select features from license plate images and a cascade classifier based on the concatenation of classifiers where each classifier is trained by an AdaBoost algorithm is used to classify parts of an image within a search window as either license plate or non-license plate. And it is followed by connected component analysis (CCA) for eliminating false positives. The two stages use different image preprocessing blocks: image preprocessing without adaptive thresholding for the first stage and image preprocessing with adaptive thresholding for the second stage. The method is faster and more accurate than most existing methods used in LPD. Experimental results demonstrate that the LPD rate is 98.38% and the average computational time is 54.64 ms.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.5
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• pp.626-630
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• 2010

Since the paper plagiarism has become one of important social issues, it is necessary to develop system for measuring the similarity between papers. The speed and accuracy of the system are very important features. So many researchers are studying the features. In this paper, we propose a preprocessing method using 'Global Dictionary' model to enhance performance of the system. The global dictionary includes information of all words in the document repository. The system uses the model to find similar papers with low computing time. Finally our experiment showed that a set of more than 20,000 documents could be reduced to about 50 documents drastically by our filtering techniques, which proves the excellence of our system.

• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.555-564
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• 2014

The boundary noise in image syntheses using DIBR consists of noisy pixels that are separated from foreground objects into background region. It is generated mainly by edge misalignment between the reference image and depth map or blurred edge in the reference image. Since hole areas are generally filled with neighboring pixels, boundary noise adjacent to the hole is the main cause of quality degradation in synthesized images. To solve this problem, a new boundary noise removal algorithm using a preprocessing of the depth map is proposed in this paper. The most common way to eliminate boundary noise caused by boundary misalignment is to modify depth map so that the boundary of the depth map can be matched to that of the reference image. Most conventional methods, however, show poor performances of boundary detection especially in blurred edge, because they are based on a simple boundary search algorithm which exploits signal gradient. In the proposed method, a two-step hierarchical approach for boundary detection is adopted which enables effective boundary detection between the transition and background regions. Experimental results show that the proposed method outperforms conventional ones subjectively and objectively.

• Journal of Navigation and Port Research
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• v.35 no.1
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• pp.77-82
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• 2011

The export of the containers consists of two steps, carrying them into the container yard and, then, out to the ship. For the safety of the ship, the heavier container should be loaded at the lower part of the ship. Because of this, the container rehandling happens during carrying out to the ship, and the number of the rehandling container is an important factor for the loading and unloading capability. There has been many studies for utilizing the idle times after loading the containers in the container yard. This study suggests the method of decreasing the number of container rehandling by preprocessing the container using the information about the weight of the container. This method is the preprocessing one which can decrease, during carrying into the container yard, the number of container rehandling which can happen during carrying out to the ship, and, according to the simulation test, it showed to be more effective than other method.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.1
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• pp.34-41
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• 2017

In this study, the effect on the zinc nuclei crystallization caused by changes preprocessing of the zinc crystalline glaze preparation has been studied. The mechanism of the nuclei formation in the crystalline glaze and development of the nuclei by studying the preprocessing step was explained. The preprocessing step was improved by altering mixing process of the materials prior to sintering: number of sieving dispersion process and ultra-sonication prove tests with various duration of sonication. According to the result, the sieving and sonication of the starting materials facilitated the interface reactions of $ZnO-SiO_2$ from $680^{\circ}C$ where low temperature willemite is formulated, and altered Si bonding for the easier bonding between Zn-Si. In other words, solely sieving was enough to accelerate the formation of willemite in low temperature. When the particles were distributed evenly by sonication, the willemite formation was even more significant.

• Journal of Conservation Science
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• v.28 no.2
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• pp.95-99
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• 2012

The compressive strength of PEG along processing concentration and solvent is willing to be measured and proper processing condition for exhibition and storage is also willing to be measured by comparing with dimensional stability. In the advanced research of setting PEG-preprocessing concentration & solvent for freeze drying of waterlogged archaeological wood of high water content, vacuum freeze drying showed the highest dimension stability after 40% PEG-preprocessing of aqueous solution. In this study, the compressive strength increased in proportion of processing concentration and water showed the relatively-higher compressive strength than t-butanol regarding solvent. Especially, it showed that there is no big strength difference between PEG 40% and PEG 50% in aqueous solution by 6.6%(16kgf/$cm^2$). According to the above results, it was recognized that it is most effective to implement freeze drying after 40% PEG-preprocessing when want to dimensional stability and compressive strength simultaneously.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.2
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• pp.203-209
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• 2015

The purpose of this study is to estimate the applicability of a stable anaerobic digester using a separator membrane to the preprocessing thickening process. The results of the experiments showed about a 47.16% weight loss rate for the sludge under anaerobic condition, and about 41.17% under intermittent aeration condition. The concentrations of rejection water were $SCOD_{Cr}$ 25 mg/L, T-N 16.6 mg/L, and T-P 1.4 mg/L on the average under the intermittent aeration condition, which were lower than the concentrations of rejection water under an anaerobic condition. As for the factors affecting the reduction of the flux, correlation analyses of TTF, MLSS, $SCOD_{Cr}$, and $EPS_{Protein}$, $EPS_{Polysacchride}$ resulted in -0.97, -0.95, -0.84 and -0.86, -0.95, respectively, which showed that TTF had the highest correlation to the reduction of the flux. In addition, it was concluded that MLSS, $SCOD_{Cr}$ and $EPS_{Protein}$, $EPS_{Polysacchride}$ also have close correlations. The results are considered to show that, in the case of the process using a tubular membrane in the preprocessing process of an anaerobic digester, an intermittent aeration condition of the thickener considering the contamination of the membrane and load of rejection water is appropriate for the stable preprocessing process.

• Journal of Biosystems Engineering
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• v.27 no.4
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• pp.341-348
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• 2002

Quality evaluation of red ginsengs is determined by outer shape and inner qualities. Especially, the inner qualities are main grading criteria. Currently, red ginsengs are classified into 3-grades; heaven, earth and good. The best heaven grade must not include inner holes and sponge tissues. This study was conducted to develop a red ginseng sorting system using x-ray image processing technique. Because of lens characteristic, gray values of the central region in the x-ray image are higher and gradually decreased towards the edge regions. This difference of gray values gives trouble in segmentation and detection of inner holes in red ginseng image, so preprocessing technique is necessary. The preprocessing was done by subtracting source image from an empty background image. But, simple subtraction was not quite appropriate because of too small contrast between inner holes and sound part. Scaled subtraction images were obtained by multiplying all gray values by some numbers. However this method could not help to set threshold value because the gray values of root part are generally lower than body part when red ginseng is exposed to the x-ray. To determine threshold value for detecting inner holes, an algorithm was developed by increasing overall gray values of less clear images.

• The Journal of the Korea Contents Association
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• v.11 no.5
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• pp.84-92
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• 2011

The automated segmentation technique of cell region in Bio Images helps biologists understand complex functions of cells. It is mightly important in that it can process the analysis of cells automatically which has been done manually before. The conventional methods for segmentation of cell and nuclei from multi-channel images consist of two steps. In the first step nuclei are extracted from DNA channel, and used as initial contour for the second step. In the second step cytoplasm are segmented from Actin channel by using Active Contour model based on intensity. However, conventional studies have some limitation that they let the cell segmentation performance fall by not considering inhomogeneous intensity problem in cell images. Therefore, the paper consider correlation between DNA and Actin channel, and then proposes the preprocessing algorithm by which the brightness of cell inside in Actin channel can be compensated homogeneously by using DNA channel information. Experiment result show that the proposed preprocessing method improves the cell segmentation performance compared to the conventional method.

• Clean Technology
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• v.18 no.3
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• pp.265-271
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• 2012

The use of renewable energies has been required to diminish the dependency on fossil fuels. As one of clean energy sources biomass has been extensively studied because various biomass resources necessitated rapid characterization of their chemical and physical properties in an on-line or real-time basis. For such an analysis near-infrared (NIR) spectroscopy has been successfully applied because of its non-invasive and informative characteristics. In this work, the applicability of nonlinear chemometric techniques based on biomass near infrared (NIR) data is evaluated for the rapid prediction of ash/char contents in different types of biomass. The prediction results of various prediction models and the effect of using preprocessing methods for NIR data are compared using six types of biomass NIR data. The results showed that nonlinear prediction models yielded better prediction performance than linear ones. It also turned out that by adopting the use of proper preprocessing methods the performance of prediction of biomass properties improved.