• Journal of the Korean Graphic Arts Communication Society
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• v.16 no.2
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• pp.45-59
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• 1998

Halftonig is a technique to create the appearance of intermideate tone levels by controlling the spatial distribution of the binary pixel values. Recently, many printing devices such as image setter, inkjet printer, laser printer and facsimile, generate image, they require the technique. Ordered dither is achieved comparing the gray scale image to periodic array. This method is fast, but it occurs periodic patterns. Conentional error diffusion generates a good image. But processing speed is very slow and appeares worm artifacts in middle tone scale. To improve it, Bns(Blue noise Screen) is developed based on Gaussian distribution. In this paper, we discribe methods to design BNS based human visual characteristics and to improve blue appearing at edge area of image by USM(using unsharp mask).

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1657-1662
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• 2017

Facial expression recognition systems using video devices have emerged as an important component of natural human-machine interfaces which contribute to various practical applications such as security systems, behavioral science and clinical practices. In this work, we present a new method to analyze, represent and recognize human facial expressions using a sequence of facial images. Under our proposed facial expression recognition framework, the overall procedure includes: accurate face detection to remove background and noise effects from the raw image sequences and align each image using vertex mask generation. Furthermore, these features are reduced by principal component analysis. Finally, these augmented features are trained and tested using Hidden Markov Model (HMM). The experimental evaluation demonstrated the proposed approach over two public datasets such as Cohn-Kanade and AT&T datasets of facial expression videos that achieved expression recognition results as 96.75% and 96.92%. Besides, the recognition results show the superiority of the proposed approach over the state of the art methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.2
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• pp.786-799
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• 2021

Road damage detection is important for road maintenance. With the development of deep learning, more and more road damage detection methods have been proposed, such as Fast R-CNN, Faster R-CNN, Mask R-CNN and RetinaNet. However, because shallow and deep layers cannot be extracted at the same time, the existing methods do not perform well in detecting objects with fewer samples. In addition, these methods cannot obtain a highly accurate detecting bounding box. This paper presents a Multi-level Feature Pyramids method based on M2det. Because the feature layer has multi-scale and multi-level architecture, the feature layer containing more information and obvious features can be extracted. Moreover, an attention mechanism is used to improve the accuracy of local boundary boxes in the dataset. Experimental results show that the proposed method is better than the current state-of-the-art methods.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1747-1753
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• 2022

Compton imaging is the main method for locating radioactive hot spots emitting high-energy gamma-ray photons. In particular, this imaging method is crucial when the photon energy is too high for coded-mask aperture imaging methods to be effective or when a large field of view is required. Reconstruction of the photon source requires advanced Compton event processing algorithms to determine the exact position of the source. In this study, we introduce a novel method based on a Deep Learning algorithm with a Convolutional Neural Network (CNN) to perform Compton imaging. This algorithm is trained on simulated data and tested on real data acquired with Caliste, a single planar CdTe pixelated detector. We show that performance in terms of source location accuracy is equivalent to state-of-the-art algorithms, while computation time is significantly reduced and sensitivity is improved by a factor of ~5 in the Caliste configuration.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.647-650
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• 2021

The most powerful and modern face recognition techniques are using deep learning methods that have provided impressive performance. The outbreak of COVID-19 pneumonia has spread worldwide, and people have begun to wear a face mask to prevent the spread of the virus, which has led existing face recognition methods to fail to identify people. Mainly, it pushes masked face recognition has become one of the most challenging problems in the face recognition domain. However, deep learning methods require numerous data samples, and it is challenging to find benchmarks of masked face datasets available to the public. In this work, we develop a new simulated masked face dataset that we can use for masked face recognition tasks. To evaluate the usability of the proposed dataset, we also retrained the dataset with ArcFace based system, which is one the most popular state-of-the-art face recognition methods.

• Journal of Environmental Health Sciences
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• v.46 no.1
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• pp.78-87
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• 2020

Objectives: To identify the degree of physical burden, a determination was undertaken of dust collection efficiency, inhalation pressure, and CO₂ concentration related to health masks certified by the Ministry of Food and Drug Safety (MFDS). Methods: Twenty health masks were purchased on the market. Dust collection efficiency and inhalation pressure were determined in the same manner as in MFDS certification testing, respectively using TSI Model 8130 (TSI, U.S.) and ART Plus (Korea). CO₂ concentrations for 20 subjects using a CO₂ analyzer (G100, G150, Geotechnical Instrument Ltd., UK) were measured with a similar method as a total inward leakage test. In addition to CO₂ levels, dead space volumes in the masks was determined for predicting concentrations of CO₂ in inhalation air. Results: Most of the dust collection efficiencies found for the 20 masks were far higher than the standard. Four KF94s met KF99 and four KF80s even met KF94. Most inhalation pressures were also much lower than the standard, with many almost one-half of the standard. The mean and standard deviation of CO₂ concentration in the mask were 2.9±0.44%. Considering dead volume, the prediction for CO₂ concentration in the inhalation air was 4,395±1,266 ppm. Conclusions: For healthy men and women, the dust collection efficiency and inhalation pressure of health masks were not at a level that would affect their health. Although CO₂ levels in the inhalation air were predicted not to affect health, research on the physiological effects of health masks on Koreans is needed for more precise research.

• Journal of the Korea Fashion and Costume Design Association
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• v.16 no.1
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• pp.105-115
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• 2014

The costumes (including mask) of the first World Master series of The National Changguk Company of Korea, Achim Freyer's 'Mr. Rabbit & Dragon king' is directly designed by Achim Freyer who was in charge of direction and stage design. The new form called Pansori opera is proposed for modernization of Korean traditional opera, it maintained the original form of music yet introduced play form of opera. The costumes and stage also promoted modernistic transformation while maintaining the original Korean form. The overall concept of 'Mr. Rabbit & Dragon king' costumes emphasizes comical effect by abstractness like childlike scribble. It expressed characteristic of characters diversely through exaggeration and expansion while maintaining original form of Hanbok, used surface of costumes as a drawing board, and created flat and geometrically transformed silhouette. The complicated characters was caricatured like everyone is doing mask play by using masks, and it still maintained sophisticated oriental color with modern application of five cardinal colors. It may seems it just mixed our traditional elements like a hint of humor, however, it could be known that it introduced various techniques in it to deliver new subject while maintaining the original form of 'Mr. Rabbit & Dragon king'. From this study, open mind for our tradition and need for diverse attempt could be rediscovered and could also see the possibility to contribute on creating a Nation Brand of traditional performing art.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.9
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• pp.4389-4411
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• 2018

High dynamic range (HDR) images are becoming pervasive due to capturing or rendering of a wider range of luminance, but their special display equipment is difficult to be popularized because of high cost and technological problem. Thus, HDR images must be adapted to the conventional display devices by applying tone mapping (TM) operation, which puts forward higher requirements for intellectual property protection of HDR images. As the robustness presents regional diversity in the low dynamic range (LDR) watermarked image after TM, which is different from the traditional watermarking technologies, a concept of watermarking activity is defined and used to distinguish the essential distinction of watermarking between LDR image and HDR image in this paper. Then, a novel robust HDR image watermarking algorithm is proposed against TM operations. Firstly, based on the hybrid processing of redundant discrete wavelet transform and singular value decomposition, the watermark is embedded by modifying the structure information of the HDR image. Distinguished from LDR image watermarking, the high embedding strength can cause more obvious distortion in the high brightness regions of HDR image than the low brightness regions. Thus, a perceptual brightness mask with low complexity is designed to improve the imperceptibility further. Experimental results show that the proposed algorithm is robust to the existing TM operations, with taking into account the imperceptibility and embedded capacity, which is superior to the current state-of-art HDR image watermarking algorithms.

• Journal of the Korea Fashion and Costume Design Association
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• v.24 no.2
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• pp.147-165
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• 2022

The purpose of this study is to examine various types and characteristics of masks and to consider what meanings they have in the recent fashion world. To this end, this study attempts to reflect on the internal meaning of masks exhibited in fashion designers' collections rather than functional meanings. It has an implication; in that it tries to help understand the expressive needs for variety and freshness pursued by modern fashion and use the unique design development to understand the internal meanings of masks. It, therefore, examines the existing domestic and foreign literature and data about masks from a theoretical perspective, and also attempts to draw findings from the data of fashion collections which have been held since the 2000s, as well as from literature research based on books about fashion and various other media. The meanings of masks in the field of fashion are as follows: First, they express identity, by criticizing the couture fashion, through the fashion. Second, they present a new concept of body, showing an illogical and ambiguous identity in which both feminine and masculine images coexist. Third, they are media externally communicating insights about human beings' inner world, through which various messages are transferred to modern people who are attached to external appearances, and the identities possessed by designers are revealed by the masks. Fourth, they ask about a boundary between gender and sexuality, as a means to make us concentrate on the important social issue, while expressing various and new identities, like the hybrid identity. In other words, they can be found to be used as effective media in communicating fashion massages intended by fashion experimental and creative designers.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.2
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• pp.194-205
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• 2012

Historically, garments have been spontaneously made with human instinct in order to warm and decorate the body using textiles that have been made and used by various peoples in different cultures. Contemporary garments have been used as a means of warming as well as express individual personality and a desire to pursue beauty. They have a unique formativeness and a symbolic nature according to cultural phenomena that reflect a cultural outcome that expresses contemporary thinking and ideology as well as their aesthetic consciousness. This study globally promotes Chinese opera mask culture and proposes the possibility of creative thinking through the introduction of Chinese opera mask elements into contemporary fashion, expressing them as patchworks. In order to endow artistic value (required in contemporary fashion) this study creates works by analyzing and applying a formative sense seen in patchwork techniques and the characteristics of Chinese opera masks; in addition, it sought the possibility of new expressions in garment designs. The results obtained from the research involve the following. First, the introduction of the traditional patchwork technique to contemporary garments may be a dynamic theme of garment expression and exceed stereotypical ideas that enable the creation of designs attuned to the globalization era. Second, it was possible to pursue independent formativeness which is in harmony with a modern sense through the restructuring of the harmony of colors and practical characteristics found in patchworks. Third, it was possible to demonstrate their artistry and unique effect in the expression of contemporary garments by the expression of the analyzed results of characteristic patterns of Chinese opera masks with a patchwork technique in creating works. Results show that it is necessary to conduct research into a patchwork technique that applies diverse materials as a new method to develop contemporary garment design also as a creative design. In addition, if the analyzed results of the characteristic patterns of Chinese opera masks can be expressed with a patchwork technique, they may be able to exhibit a genuine effect along with the artistry of expression in contemporary garments; thereby, relevant follow-up research should be further continued.