• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.3
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• pp.256-265
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• 2017

In this paper, an ascheme is proposed for multiuser underwater acoustic communication by using the multi-chirp rate signals. It differs from the well known TDMA (Time Division Multiple Access), FDMA (Frequency Division Multiple Access) or CDMA (Code Division Multiple Access), by assigning each users with different chirp-rate carriers instead of the time, frequency or PN code. Multi-chirp rate signals can be separated from each other by FrFT (Fractional Fourier Transform), which can be regarded as the chirp-based decomposing, and superior to the match filter in the underwater acoustic channel. VTRM (Virtual Time Reverse Mirror) is applied into the system to alleviate the ISI caused by the multipatch and make the equalization more simple. Results of computer simulations and pool experiments prove that the proposed multiuser underwater acoustic communication based on the multi-chirp rate exhibit well performance. Outfield experments carrie out in Xiamen Port show that using about 10 kHz bandwidth, four users could communicate at the same time with 425 bps with low BER and can match the UAC application.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.562-562
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• 2014

Assessment of aerodynamic noise is becoming increasingly important for automotive manufacturers. Flow passing a vehicle may indeed lead to high interior noise level and affect cabin comfort. Interior noise results from various mechanisms including aerodynamic fluctuations of the disturbed flow around the side mirror or pillar, hydrodynamic and acoustic loading of the car panels and windows, vibration of these panels and acoustic radiation inside the vehicle. Objective of the present study is to capture these important mechanisms in a simulation model and demonstrate the ability of the combined simulation tools Fluent / Virtual.Lab to provide accurate aerodynamic and interior noise prediction results. Previous study focused on the noise generated by the turbulence around the A-pillar structure of the HSM (Hyundai simplified model). The present study also includes the effect of the side-mirror and rain-gutter structures. Complete modeling process is presented including details on the unsteady CFD simulation and the vibro-acoustic model with absorption materials. Guidelines and best practices for building the simulation model are also discussed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.2.1-2.7
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• 2018

With the development of computer-aided design/computer-aided manufacturing (CAD/CAM) technology, it has been possible to reconstruct the cranio-maxillofacial defect with more accurate preoperative planning, precise patient-specific implants (PSIs), and shorter operation times. The manufacturing processes include subtractive manufacturing and additive manufacturing and should be selected in consideration of the material type, available technology, post-processing, accuracy, lead time, properties, and surface quality. Materials such as titanium, polyethylene, polyetheretherketone (PEEK), hydroxyapatite (HA), poly-DL-lactic acid (PDLLA), polylactide-co-glycolide acid (PLGA), and calcium phosphate are used. Design methods for the reconstruction of cranio-maxillofacial defects include the use of a pre-operative model printed with pre-operative data, printing a cutting guide or template after virtual surgery, a model after virtual surgery printed with reconstructed data using a mirror image, and manufacturing PSIs by directly obtaining PSI data after reconstruction using a mirror image. By selecting the appropriate design method, manufacturing process, and implant material according to the case, it is possible to obtain a more accurate surgical procedure, reduced operation time, the prevention of various complications that can occur using the traditional method, and predictive results compared to the traditional method.

• Journal of the Korea Computer Graphics Society
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• v.17 no.3
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• pp.21-31
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• 2011

This paper presents a practical method to estimate the directions of light sources in real environment, using a mirror sphere placed on a set of known natural features in augmented reality. For the stable result of static lighting, we take the multiple images around the sphere and estimate the principal light directions of the vector clusters for each light source in realtime. We also estimate the moving illuminant for changes of the scene illumination, and augment the virtual objects onto the real image with the proper highlighting and shadows. The proposed method of this paper can be applied to augmented reality visualization without any previous information respecting the environmental illuminations.

• Journal of Multimedia Information System
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• v.8 no.3
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• pp.167-174
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• 2021

This paper compares VR cinema with interactive cinema from an interactive perspective to examine cinemas as a new medium. Rather than revealing the difference through this, the focus is on presenting a methodology that understands the cinema in a new environment that is now standing at the starting point. The development of video technology is changing not only the external elements of content but also the internal storytelling method, but the lack of killer content has always been pointed out as a problem compared to the remarkable development of technology. Therefore, it is necessary to specify the characteristics and types of interactions represented by VR (virtual reality) and new media represented by interactive media and to present directions. Therefore, the types and characteristics of interactions were compared with VR film produced in line with the new phenomenon and interactive film . Through this, we would like to present the meaning and value of the new film format from a media perspective.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.4
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• pp.155-165
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• 2013

For the service and creation of new space, the next generation smart device for interactive space using tailor-made contents process serve as an opportunity for the growth of new special display due to the integration of the latest digital technology. The application of next generation technology is in the field that most people expect. So, this thesis serving as the beginning, it is hoped that the smart mirror and wall industry in Korea will play a practical and academic momentum. An interactive environment which is the smart device can be realized when space displays based on smart device built on the experience of the user can provide various tailor-made processes such as academics, performances, meetings, virtual experience, exhibits and promotion, and through this a strategic direction was suggested for the development of each field.

• Journal of the HCI Society of Korea
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• v.8 no.2
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• pp.21-27
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• 2013

Recently, the use of floating hologram has increased in many different aspects, such as exhibitions, education, advertisements, and so on. Especially, the floating hologram that makes use of half-mirror is widely used. Nevertheless, half-mirror, unfortunately, cannot lead users to the perfect three dimensional hologram experience. Even though it can make the vision look to be up on the air, it does not have the capacity to display itself up on the air, which is the ultimate goal of hologram. In addition, it looks inconsistent when a real object is located behind the half-mirror in order to show the convergence of the two (object and the half-mirror). In this paper, we did the study on comparison of 3D space perception for the stereoscopic AR holography. At first, we applied stereoscopic technology to the half-mirror hologram system for the accurate and realistic AR environment. Then, the users can feel as if the real 3D object behind half-mirror and the reflected virtual image are converged much better in the 3D space. Furthermore, by using depth camera, the location and direction of graphics can be controlled to change depending on the user's point of view. This is the effective way to produce augmented stereoscopic images simply and accurately through half-mirror film without any additional devices. What we saw from the user test were applying 3D images and user interaction leads the users to have 3D spatial awareness and realism more effectively and accurately.

• Journal of the Korea Fashion and Costume Design Association
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• v.25 no.2
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• pp.31-44
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• 2023

Fashion design in the metaverse is not simply a 3D avatar or virtual fashion, it is an important clue for shopping trends, and the role of fashion design has grown even more because avatars and humans are identified and active. This study, I attempts to understand the metaverse platform accurately and find out the scope of fashion design within the metaverse platform. In addition, we want to provide basic data that can expand the field by using fashion design in various ways on the metabus platform. This study investigated and analyzed various metaverse fashion cases, articles, software, and methods used by metaverse fashion creators, and the results are as follows. First, the metaverse platform is a new level of virtual interaction where users and creators communicate through the convergence of augmented reality, lifelogging, mirror world, and virtual world. Second, most of the users of the metaverse platform are generation Z, and metaverse creators who make money by producing avatars or items, including fashion design, are emerging as a new job field. Third, many fashion brands created spaces on the Metaverse platform, collaborated with games, or opened fashion weeks for publicity, marketing, and sales. Fourth, as a 3D program for metaverse fashion creator activities, open-source software is easier and free of charge compared to programs for fashion design specialists, and most costumes can be reproduced, so it will be easier for fashion design majors to utilize.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6105-6110
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• 2012

Smart devices have made our daily life more intelligent and provided convenient life styles in which advanced interface and high speed LTE enable us to have proliferation of empirical Apps. This research has analyzed and evaluated Unstructured data from the users who experienced 'Hair Style Magic Mirror App' by focusing on emotional information. Further this study suggests some directions that the application development industry should take in the near future. The findings through Chi-Square analysis indicate that the application has not affected the overall satisfaction of the consumers; consumers received higher satisfaction in paid version of applications than free versions. Emotional Information analysis shows that users value the practicality of each application the most. Thus, the application developers should focus on practicality and sensitivity side corresponding to the demand of consumers.

• Smart Media Journal
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• v.10 no.4
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• pp.111-120
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• 2021

This study looked at how the digital cultural heritage, which is being actively built by the government and public institutions, can be utilized in the metaverse service. Through an expert interview, we investigated how the digital cultural heritage of Bulguksa can be serviced with the four elements of the metaverse: augmented reality, mirror world, lifelogging, and virtual world. As a result of the study, it was confirmed that when digital cultural heritage is used in a virtual space called metaverse, interactive and realistic services can be provided to users. In addition, it was found that users can exhibit, experience, and educate online parts that are not available in real life in the same situation as if they were in the field. Through this, it was confirmed that if digital cultural heritage is designed as a metaverse service, it can provide functions and services of a different level than before. In particular, the result was obtained that it is possible to provide services considering the characteristics of each of the four elements of the metaverse. First, it is possible to obtain the convenience of augmenting the senses by using augmented reality, and secondly, it is possible to obtain the scalability and efficiency of reproducing the real space by using it as a mirror world element. Third, by using the lifelogging element, communication can be strengthened through the user's record and connection, and fourthly, through the virtual world element, roles and activities in the virtual world can be given to the user. Therefore, if digital cultural heritage is developed as a metaverse service in consideration of these factors, a more active and open experience environment can be provided to users.