• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.4
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• pp.148-156
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• 2009

This paper presents a new image rejection algorithm based on the analysis of the distortion of a single-frequency continuous-wave (CW) signal due to the I/Q mismatch. Existing methods estimated the gain mismatch and phase mismatch on RF receivers and compensated them However, this paper shows that the circular trajectory of a single-frequency CW signal is distorted elliptic-type trajectory due to the I/Q mismatch. Utilizing the analysis, we propose a I/Q mismatch compensation method. It has two processing steps. In the first processing step, the generated signal is rotated to align the major axis of the elliptic-type trajectory diagram with the x-axis. In the second processing step, the Q-channel signal in the regenerated signal is scaled to align the regenerated signal with the transmitted single-frequency CW signal. Simulation results show that a receiver using the proposed image rejection algorithm can achieve an image rejection ratio of more than 70dB. And, simulation results show that the bit error rate performances of receivers using the proposed image rejection algorithm are almost the same as those of conventional coherent demodulators, even in fading channels.

• Journal of the Korea Computer Graphics Society
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• v.21 no.1
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• pp.1-11
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• 2015

Researchers have developed virtual reality environments to provide audience with more visually immersive experiences than previously possible. One of the most popular solutions to build the immersive VR space is a multi-projection technique. However, utilization of multiple projectors requires large spaces, expensive cost, and accurate geometry calibration among projectors. This paper presents a novel omnidirectional projection system with a single projector and a single spherical mirror.We newly designed the simple and intuitive calibration system to define the shape of environment and the relative position of mirror/projector. For successful image projection, our optimized omnidirectional image generation step solves image distortion produced by the spherical mirror and a calibration problem produced by unknown parameters such as the shape of environment and the relative position between the mirror and the projector. Additionally, the focus correction is performed to improve the quality of the projection. The experiment results show that our method can generate the optimized image given a normal panoramic image for omnidirectional projection in a rectangular space.

• Journal of the Korean Society of Radiology
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• v.10 no.4
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• pp.241-246
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• 2016

The purpose of this study was to investigate the problems of low signal-to-noise ratio(SNR) of single-shot turbo spin echo(SS-TSE) by quantifying numerically decreased signal to noise ratio. Thirty five patients without brain disease underwent diffusion MRI in 3T scanner from July to October in 2015. Single shot echo planar imaging(SS-EPI) which is conventionally used in MRI was taken to compared SS-TSE in SNR of medulla oblongata. As a result, SNR of SS-TSE diffusion(b0=$314.41{\pm}42.96$, b1000=$117.33{\pm}14.04$) is than SS-EPI diffusion(b0=$514.84{\pm}48.97$, b=$208.65{\pm}25.70$) lower in b=0 image(38.9%) and b=1,000 image(43.8%). Thus, diffusion MR using SS-EPI of MS-EPI should be taken for diagnosis of disease in brain stem due to decreased SNR of diffusion using SS-TSE.

• Fashion & Textile Research Journal
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• v.11 no.1
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• pp.14-23
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• 2009

This study is to analyze the regional differences of sensibility image of wedding dress design for single women of marriageable age in Ulsan and Seoul. The conclusions of this study were as follows. In silhouette, both of two regions were not significant differences but within the same sensibility image there was a bit of differences. In neckline, reminded sweetheart of pure image, yet those of Ulsan reminded sweetheart of feminine image. Both of two regions reminded V of hard image, boat of feminine image, square of hard image, halter of complex image. But within the same sensibility image there was a bit of differences between two regions. Oval was significant differences between two regions. Subject of Ulsan reminded oval of mature image, yet those of Seoul reminded oval of elegance image. It was reminded ruffle of complex image. Subject of Ulsan reminded china of hard image, yet those of Seoul reminded china of calm image. In material, it was not significant differences between two regions, but within the same sensibility image there was a bit of differences between two regions. In detail, subject of Ulsan reminded ruffle of messy image, yet those of Seoul reminded ruffle of complex image. Both of two areas reminded ribbon of pure image, button of pure image. Subject of Ulsan reminded beads of feminine image, yet those of Seoul reminded beads of pure image. In conclusion, it could be said that there was no major differences in sensibility image for wedding dress design between Ulsan and Seoul.

• Journal of Korea Multimedia Society
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• v.19 no.6
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• pp.990-1002
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• 2016

In this paper, we propose a new compression method for the edge image by analyzing the characteristics and the distribution of pixel values of the edge image. The pixel values of the edge image have the Gaussian distribution around '0', and most of the pixel values are `0`. By these analyses we suggest the Zero-Based codec that expresses all values in a CU by a single bit flag. Also, in order to reduce the computational complexity of the proposed codec, the block partition and the intra-prediction techniques are proposed by using edge information like the number of each edge direction, the distribution and the amplitude of a major edge direction in the CU. Experimental results show that the proposed codec leads to a slighter distortion in Y domain than that of HEVC, but has far faster processing speed up to 53 times while it maintains the similar image quality compared to HEVC.

• Journal of IKEEE
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• v.18 no.1
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• pp.77-95
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• 2014

In general, image acquisition characteristics tests of image sensors and modules vary widely according to the characteristics of image sensors and modules under test, the application purpose of target devices where image sensors and modules are mounted, and the functions of test equipments. However, some de facto standard tests are frequently used in industry fields. They differ only in several parameters e.g. thresholds for fault detection, and they can be applied to most image sensors and modules. In this paper, 11 typical tests are explained in detail, and they are described in a simple and clear form under single framework, which significantly reduces errors and saves efforts.

• Journal of Broadcast Engineering
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• v.21 no.2
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• pp.272-275
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• 2016

This paper presents a method of single image dehazing and surface-based feature detection for remote sensing images. In the conventional dark channel prior (DCP) algorithm, the resulting transmission map invariably includes some block artifacts because of patch-based processing. This also causes image blur. Therefore, a refined transmission map based on a hidden Markov random field and expectation-maximization algorithm can reduce the block artifacts and also increase the image clarity. Also, the proposed algorithm enhances the accuracy of image matching surface-based features in an remote sensing image. Experimental results confirm that the proposed algorithm is superior to conventional algorithms in image haze removal. Moreover, the proposed algorithm is suitable for the problem of image matching based on feature extraction.

• Journal of Fashion Business
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• v.26 no.5
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• pp.22-35
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• 2022

This study examines the image pursuit behavior according to body surveillance, body shame of image-based SNS-used women. Questionnaires were administered to 215 SNS-used women aging between 20 to 30 years old. The SPSS 25.0 package was utilized for data analysis, which included frequency analysis, factor analysis, Cronbach's α, correlation analysis and regression analysis. The study analyzed the relationship between body surveillance, body shame single factor, and subfactors of image pursuit behavior(conformity, instrumentality, fashion pursuit, attractiveness pursuit, ostentation pursuit, interpersonal). It was observed that body surveillance and body shame had a positive influence on all the factors of image pursuit behavior. Body surveillance demonstrated a high influence on attractiveness pursuit while body shame demonstrated a high influence on ostentation pursuit. Body surveillance had a positive influence on body shame. These results provide useful information for understanding the influence of social media on the psychological attitude and consciousness of women with regard to their body and image pursuit behavior. In addition, results from this study will help to systematize women's theoretical physical consciousness, establish product strategies for physical appearance-related industries, and set marketing directions.

• International Commerce and Information Review
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• v.19 no.1
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• pp.67-98
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• 2017

This study intended to investigate to what extent country image of America and previous visit experience affect the cross-border shopping intention. In particular, the present study used a country image measurement brought from another research study the factors of which are economy-technology image, social-cultural image, and citizen image. A total of 155 respondents participated in the survey targeting Korean citizen for the present study. Single regression, multiple regression, and independent t-test were conducted for data analysis. The result of the single regression indicated that country image is a critical predictor of cross-border shopping intention. The Multiple regression revealed that among three factors composing country image, social-cultural image plays the most significant and economy-technology image plays the second-most significant role in influencing cross-border shopping intention. However, it was found that citizen image does not play a substantial role for some reason. Moreover, the result of t-test showed that those who have a prior visit experience to America are more likely to buy products online from America than those who don't have prior visit experience. More detailed findings and implications will be discussed in the manuscript.

• The Transactions of the Korea Information Processing Society
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• v.5 no.12
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• pp.3275-3284
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• 1998

In this paper, we deseribe a Medical Image Information System. Our system stores and manages 5 dimensional medical image data and provides the 3 dimensional medical data via the Internet. The Internet standard VR format. VRML(Virtual Reality Modeling Language) is used to represent the 3I) medical image data. The 3D images are reconstructed from medical image data which are enerated by medical imaging systems such ans CT(Computerized Tomography). MRI(Magnetic Resonance Imaging). PET(Positron Emission Tomograph), SPECT(Single Photon Emission Compated Tomography). We implemented the medical image information system shich rses a surface-based rendering method for the econstruction of 3D images from 2D medical image data. In order to reduce the size of image files to be transfered via the Internet. The system can reduce more than 50% for the triangles which represent the surfaces of the generated 3D medical images. When we compress the 3D image file, the size of the file can be redued more than 80%. The users can promptly retrieve 3D medical image data through the Internet and view the 3D medical images without a graphical acceleration card, because the images are represented in VRML. The image data are generated by various types of medical imaging systems such as CT, MRI, PET, and SPECT. Our system can display those different types of medical images in the 2D and the 3D formats. The patient information and the diagnostic information are also provided by the system. The system can be used to implement the "Tele medicaine" systems.