• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.2
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• pp.188-194
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• 2010

In this paper, the typical Synthetic Aperture Radar (SAR) image quality parameters and analysis method are defined, and the SAR image analysis tool is presented for SAR image evaluation. The structure of the developed SAR image analysis tool consists of four key modules; point target analysis (PTA) module, distributed target analysis (DTA) module, ambiguity analysis (AMA) module, and NESZ analysis (NESZA) module. The developed tool is able to extract the various SAR system parameters from standard SAR product format files. Based on these extracted system parameters, typical SAR image quality parameters are derived from SAR image data.

• Progress in Medical Physics
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• v.33 no.4
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• pp.37-52
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• 2022

Over the past decades, radiation therapy combined with imaging modalities that ensure optimal image guidance has revolutionized cancer treatment. The two major purposes of using imaging modalities in radiotherapy are to clearly delineate the target prior to treatment and set up the patient during radiation delivery. Image guidance secures target position prior to and during the treatment. High quality images provide an accurate definition of the treatment target and the possibility to reduce the treatment margin of the target volume, further lowering radiation toxicity and improving the quality of life of cancer patients. In this review, the various types of image guidance modalities used in radiation therapy are distinguished into ionized (kilovoltage and megavoltage image) and nonionized imaging (magnetic resonance image, ultrasound, surface imaging, and radiofrequency). The functional aspects, advantages, and limitation of imaging using these modalities are described as a subsection of each category. This review only focuses on the technological viewpoint of these modalities and any clinical aspects are omitted. Image guidance is essential, and its importance is rapidly increasing in modern radiotherapy. The most important aspect of using image guidance in clinical settings is to monitor the performance of image quality, which must be checked during the periodic quality assurance process.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.111-120
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• 2020

Research should be actively conducted for the ability of X-ray equipment and Retrospective image analysis of X-ray equipment used in hospitals. Retrospective image analysis of X-ray machines, CT and MRI of radiology and medical equipment has been actively conducted. However, image quality measurement using angiography equipment of angiography room is mostly measured with phantom, and image quality measurement on image after being taken by actual patient is insufficient and researches on accurate image quality measurement method are remarkable. It is in short supply. Therefore, through this study, the researcher devised a method to measure the image quality of the acquired image after coronary angiography, and to provide a high quality image to the operator. The equipment and programs used were angiographic examination equipment (Axiom Artis Zee Ceiling) and Image J program. Subjects were images automatically saved in PACS program after coronary angiography.For image quality measurement, selected the AP Caudal 30° image that show the LCA vessel well and the LAO 30° image that show the RCA vessel well during the coronary angiography. In order to measure the background and ROI of the selected image by selecting an image, a criterion on how to find and measure a section where the overlap of the shadow, such as blood vessel, liver and lung is minimized, is presented. In conclusion, there is no exact standard for analyzing an image quality measurement method of angiography image. Therefore, in order to provide quality images to the practistioners, not only the technicians of the equipment but also the users who actually use them should become researchers and conduct research on image quality measurement in various ways. Thus, it is expected to provide excellent images to patients.

• Journal of Korea Multimedia Society
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• v.9 no.8
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• pp.971-981
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• 2006

As shear-warp volume rendering is the fastest rendering method among the software based approaches, image quality is not good as that of other high-quality rendering methods. In this paper, we propose two methods to improve the image quality of shear-warp volume rendering without sacrificing computational efficiency. First, supersampling is performed in intermediate image space. We propose an efficient method to transform between volume and image coordinates at the arbitrary ratio. Second, we utilize pre-integrated rendering technique for shear-warp rendering. We propose new data structure called overlapped min-max map. Using this structure, empty space leaping can be performed so that we can maintain the rendering speed even though pre-integrated rendering is applied. Consequently, shear-warp rendering can generate high-qualify images comparable to those generated by the ray-casting without degrading speed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3923-3927
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• 2010

Primary charging roller rotated with contacting surface of OPC drum and take charge OPC drum. Owing to this reason, primary charging roller is made by elasticity substance with electric conduction. Properties of charging and image is changed by class of coating, method of coating and environment. This study developed coating material and coating method to make Image Forming of High- quality.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.6
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• pp.22-34
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• 2010

Existing image scalers generally adopt simple interpolation methods such as bilinear method to take cost-benefit, or highly complex architectures to achieve high quality resulting images. However, demands for a low power, low cost, and high performance image scaler become more important because of emerging high quality mobile contents. In this paper we propose the novel low power hardware architecture for a high quality raster scan image scaler. The proposed scaler architecture enhances the existing cubic interpolation look-up table architecture by reducing and optimizing memory access and hardware components. The input data buffer of existing image scaler is replaced with line memories to reduce the number of memory access that is critical to power consumption. The cubic interpolation formula used in existing look-up table architecture is also rearranged to reduce the number of the multipliers and look-up table size. Finally we analyze the optimized parameter sets of look-up table, which is a trade-off between quality of result image and hardware size.

• The Journal of Natural Sciences
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• v.4
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• pp.191-220
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• 1991

A new texture segmentation-based image coding technique which performs segmentation based on roughness of textural regions and properties of the human visual system (HVS) is presented. This method solves the problems of a segmentation-based image coding technique with constant segments by proposing a methodology for segmenting an image texturally homogeneous regions with respect to the degree of roughness as perceived by the HVS. The fractal dimension is used to measure the roughness of the textural regions. The segmentation is accomplished by thresholding the fractal dimension so that textural regions are classified into three texture classes; perceived constant intensity, smooth texture, and rough texture. An image coding system with high compression and good image quality is achieved by developing an efficient coding technique for each segment boundary and each texture class. For the boundaries, a binary image representing all the boundaries is created. For regions belonging to perceived constant intensity, only the mean intensity values need to be transmitted. The smooth and rough texture regions are modeled first using polynomial functions, so only the coefficients characterizing the polynomial functions need to be transmitted. The bounda-ries, the means and the polynomial functions are then each encoded using an errorless coding scheme. Good quality reconstructed images are obtained with about 0.08 to 0.3 bit per pixel for three different types of imagery ; a head and shoulder image with little texture variation, a complex image with many edges, and a natural outdoor image with highly textured areas.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3591-3606
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• 2014

In this paper, a robust watermarking scheme is proposed that uses the scale-invariant feature transform (SIFT) algorithm in the discrete wavelet transform (DWT) domain. First, the SIFT feature areas are extracted from the original image. Then, one level DWT is applied on the selected SIFT feature areas. The watermark is embedded by modifying the fractional portion of the horizontal or vertical, high-frequency DWT coefficients. In the watermark extracting phase, the embedded watermark can be directly extracted from the watermarked image without requiring the original cover image. The experimental results showed that the proposed scheme obtains the robustness to both signal processing and geometric attacks. Also, the proposed scheme is superior to some previous schemes in terms of watermark robustness and the visual quality of the watermarked image.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.76-80
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• 2003

Recently as new digital media like High Definition Television (HDTV) have been made popularization. However In case of image quality characteristics of AC PDP, the problem especially raised is 'image sticking' phenomenon, the phenomenon that the previously displayed pattern still remains after the image in realizing high picture quality. In this paper, Image sticking Phenomena observed in AC PDP are defined and classified, these effects are analyzed as luminance, color purity through chromaticity diagram and firing voltage state using light waveform.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.5
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• pp.752-763
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• 2009

The purpose of this study was to develop an effective marketing strategy for socks made of paper mulberry fiber, a new natural fiber, by understanding consumers' concerns and perception about the product and its quality in several dimensions. The first survey determined their perception of the products' image before using it. The second survey gauged consumer satisfaction with product quality after a two-week home-use test. Factor analysis using Cronbach's a and ANOVA analysis were performed for statistical analysis. In conclusion, consumer image perceptions of socks of mulberry fiber were classified into four categories -'practicality', 'wellbeing', 'high-quality' and 'traditionality'. The survey revealed differences between men's and women's perception of the 'practicality' and 'high-quality' factors. The women recognized a mulberry fiber sock as being more practical but of lower quality than did the men. And the quality satisfaction of the product was classified into four factor 'durability', 'suitability, 'wearability' and 'care-easiness'. In the case of 'suitability', men were more satisfied with the product than the women and in 'suitability' and 'wearability', a group of over 40' year-old consumers was more satisfied. The analysis of a relationship between image perception and satisfaction showed that a consumer group that perceived this product to have more 'practicality', 'high-quality' and 'well-being' was also more satisfied with the product. However, the 'traditionality' factor was unrelated to consumer satisfaction.