• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.407-410
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• 2005

For reducing DFC(Dynamic False Contour), we propose a new PDP driving method by rearrangement of sub-fields. The proposed method constructs a frame using 16 sub-fields for expressing 256 gray levels. Although the number of sub-fields increases, the display time increases compared to the conventional 8 sub-fields driving method. This increase in display time is achieved by properly using both selective writing and selective erasing for each sub-field.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.927-930
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• 2004

We report on a new type of a flat and thin display with a secondary emission electron source. In this display device electrons are multiplied between two secondary emission plates under a high frequency electric field. This principle has a few important advantages over a field emission display: the emission comes from flat plates, which reduces the life-time problems of ion bombardment of field emitter tips. Furthermore, the electron emission is space charge limited which gives a uniform electron distribution. The electrons are extracted from the source and accelerated to a phosphor screen to generate light. Gray levels are made by pulse width modulation.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.911-914
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• 2004

This paper discusses on new two LCD technologies featured by the fast electro-optic response:one is polymer-stabilized FLCDs that exhibit V-shaped electro-optic (EO) switching called PSV-mode FLCDs with response time of 400 ${\mu}$ s; and the other is TN-mode LCDs that exhibit a frequency modulation response (called PM-TN LCDs)and a peculiar sensitivity to the high frequency component of driving voltage waveforms resulting in a short decay time constant of 5ms and an enhancement in the over-driving that yields short response time of 1ms between two gray levels.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.102-111
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• 1990

In this thesis, an optical bidirectional inner-product associative memory model using liquid crystal television is proposed and analyzed theoretically and realized experimentally. The LCTV is used as a SLM(spatial light modulator), which is more practical than conventional SLMs, to produce image vector in terms of computer and CCD camera. Memory and input vectors are recorded into each LCTV through the video input connectors of it by using the image board. Two multi-focus hololenses are constructed in order to perform optical inner-product process. In forward process, the analog values of inner-products are measured by photodetectors and are converted to digital values which are enable to control the weighting values of the stored vectors by changing the gray levels of the pixels of the LCTV. In backward process, changed stored vectors are used to produce output image vector which is used again for input vector after thresholding. After some iterations, one of the stored vectors is retrieved which is most similar to input vector in other words, has the nearest hamming distance. The experimental results show that the proposed inner-product associative memory model can be realized optically and coincide well with the computer simulation.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.17-26
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• 2005

In this paper we propose three nonparametric tests such as Wilcoxon test, Median test and Van der Waerden test, based on linear rank statistics for detecting edges in images. The methods used herein are based on detecting changes in gray-levels obtained using an edge-height parameter between two sub-regions in a 5$\times$5 window We compare and analysis the performance of three statistical edge detectors in terms of qualitative measures with the edge maps and objective, quantitative measures.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.644-647
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• 2003

This paper describes a neural network based machine vision system designed for inspecting yellow beans in real time. The system consists of a camera. lights, a belt conveyor, air ejectors, and a computer. Beans are conveyed in four lines on a belt and their images are taken by a monochrome line scan camera when they fall down from the belt. Beans are separated easily from their background on images by back-lighting. After analyzing the image, a decision is made by a multilayer artificial neural network (ANN) trained by the error back-propagation (EBP) algorithm. We use the global mean, variance and local change of gray levels of a bean for the input nodes of the network. In an our experiment, the system designed could process about 520kg/hour.

• The Korean Journal of Applied Statistics
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• v.14 no.1
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• pp.149-160
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• 2001

In this paper we employ two-sample location tests such as Wilcoxon test and T test for detecting edges in noisy images. For this, we compute a test statistic on pixel gray levels obtained using an edge-height parameter and compare it with a threshold determined by a significance level. Experimental results applied to sample images are given and performances of these tests in terms of the objective measure are compared.

• Biomedical Science Letters
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• v.11 no.1
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• pp.23-29
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• 2005

Molecular imaging with targeted contrast agents enables tissues to be distinguished by detecting specific cell-surface receptors. In the present study, a ligand-targeted acoustic nanoparticle system is used to identify angioplasty-induced expression of tissue factor by smooth muscle cell within carotid arteries. Pig carotid arteries were overstretched with balloon catheters, treated with tissue factor-targeted or a control nanoparticle system, and imaged with intravascular ultrasound before and after treatment. Tissue factor-targeted emulsion bound and increased the echogenicity and gray-scale levels of overstretched smooth muscle cell within the tunica media, versus no change in contralateral control arteries. Expression of stretch-induced tissue factor in carotid artery media was confirmed by immunohistochemistry. The potential for abnormal thrombogenicity of balloon-injured arteries, as reflected by smooth muscle expression of tissue factor, was imaged using a novel, targeted, nanoparticulate ultrasonic contrast agent.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.9
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• pp.1-10
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• 2006

In this paper, a new high resolution XGA-SLM is implemented through modification of a commercial TFT-LCD beam projector and its optical modulation characteristics as a spatial light modulator(SLM) is also analyzed. First, the optics module, projection lamp and fans are removed from a commercial beam projector and instead some electric circuits to compensate their removal are manufactured and then, by inserting them into the beam projector, a new XGA-SLM is finally implemented. Second, from some optical experimental results, this TFT-SLM is found to have a good optical linearity in amplitude and phase modulation characteristics as a function of the input gray levels. Especially, through implementation of a binary phase-type correlator such as BPEJTC by using the suggested TFT-LCD panel, the implemented SLM is proposed as a new relatively low-cost and high resolution SLM for optical information processing.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.11
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• pp.4869-4873
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• 2016

Colonoscopy is currently the best technique available for the detection of colon cancer or colorectal polyps or other precursor lesions. Computer aided detection (CAD) is based on very complex pattern recognition. Local binary patterns (LBPs) are strong illumination invariant texture primitives. Histograms of binary patterns computed across regions are used to describe textures. Every pixel is contrasted relative to gray levels of neighbourhood pixels. In this study, colorectal polyp detection was performed with colonoscopy video frames, with classification via J48 and Fuzzy. Features such as color, discrete cosine transform (DCT) and LBP were used in confirming the superiority of the proposed method in colorectal polyp detection. The performance was better than with other current methods.