• Journal of Broadcast Engineering
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• v.19 no.3
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• pp.342-354
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• 2014

This paper deals with digital watermarking methods to protect ownership of image with targeting the ultra-high multi-view or free-view image service in which an arbitrary viewpoint image should be rendered at the user side. The main purpose of it is not to propose a superior method to the previous methods but to show how difficult to construct a watermarking scheme to overcome the viewpoint translation attack. Therefore we target the images with various attacks including viewpoint translation. This paper first shows how high the error rate of the extracted watermark data from viewpoint-translated image by basic schemes of the method using 2DDCT(2D discrete cosine transform) and the one using 2DDWT(2D discrete wavelet transform), which are for 2D image. Because the difficulty in watermarking for the viewpoint-translated image comes from the fact that we don't know the translated viewpoint, we propose a scheme to find the translated viewpoint, which uses the image and the corresponding depth information at the original viewpoint. This method is used to construct the two non-blind watermarking methods to be proposed. They are used to show that recovery of the viewpoint affect a great deal of the error rate of the extracted watermark. Also by comparing the performances of the proposed methods and the previous ones, we show that the proposed ones are better in invisibility and robustness, even if they are non-blind.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.5
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• pp.1728-1743
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• 2021

Three-dimensional (3D) video scenes are complex and difficult to control, especially when scene switching occurs. In this paper, we propose two algorithms based on an incremental proportional-integral-derivative (PID) algorithm and a similarity analysis between views to improve the method of bit allocation for multi-view high efficiency video coding (MV-HEVC). Firstly, an incremental PID algorithm is introduced to control the buffer "liquid level" to reduce the negative impact on the target bit allocation of the view layer and frame layer owing to the fluctuation of the buffer "liquid level". Then, using the image similarity between views is used to establish, a bit allocation calculation model for the multi-view video main viewpoint and non-main viewpoint is established. Then, a bit allocation calculation method based on hierarchical B frames is proposed. Experimental simulation results verify that the algorithm ensures a smooth transition of image quality while increasing the coding efficiency, and the PSNR increases by 0.03 to 0.82dB while not significantly increasing the calculation complexity.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.425-429
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• 2004

A new multi-level type energy recovery sustaining driver for AC PDP(Plasma Display Panel) is proposed in this paper. The multi-level driver has been developed to reduce the voltage stress on switching elements. Comparing the proposed driver with the conventional multi-level driver, 4 switching elements, 4 diodes, and two auxiliary capacitors are eliminated in the viewpoint of circuit structure. Moreover, the voltage stress on switching elements is more reduced and the sustain period is extended. To verify the validity of the proposed energy recovery circuit, computer simulations using PSpice program are carried out.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.1
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• pp.9-16
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• 1994

In this paper, we propose a frequency assignment algorithm to minimize intermodulation effect which is caused by nonlinear amplipification of the satellite transponder. Allmost all of the published algorithms up to now are applicable to one-level SCPC systems, the application range of those algorithms is very restricted from the viewpoint of actual practice. In this paper, we develope and propose a new frequency assignment algorithm which utilize the basic concept of Okinaka's DELINS-INSDEL algorithm to extend its applicabilty from one-level SCPC systems to multi-level systems. The proposed TDTI algorithm provides considerable generality in reducing intermodulation effect in practical satellite communication systems because of its alpplicability to multi-level and multi-bandwidth systems as well as one-level systems. Besides the TDTI algorithm which shows excellent characteristics in performance but requires somewhat long excution time. the WTDI-SDELINS algorithm is proposed in this paper to compensate TDTI's demerits in excution time. Considering the fact that there are very little published sterategies for multi-level and muti-bandwidth systems. the algorithm proposed in this paper is quite meaningful.

• Journal of Internet of Things and Convergence
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• v.2 no.1
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• pp.29-33
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• 2016

This study aims to analyze the change in communication after the advent of internet in the viewpoint of multi-dimensional communication network, Especially this study tried to explain that the multi-dimensional communication network leads to p luralization of society. And it analyzed the increase of consumer activeness in commercial communication in multi-dimensional communication network.

• Journal of the Korea Society for Simulation
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• v.14 no.3
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• pp.55-66
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• 2005

Virtual reality (VR) simulators have been extended to transfer knowledge and education, and demands for exhibition systems for science education and cultural experiences has also increased. Existing VR simulators, which are based on the dynamics equations of motion, cannot easily be adapted to changes in simulation contents. In order to effectively transfer knowledge and maintain interests through educational applications, an experiential system that has multi-sensory effects as well as motion effects is required. In this study, we designed and implemented a motion generation that is tailored to experiential exhibition systems and multi-sensory VR effects. Both the sense of motion which is generated from the movement of the viewpoint of the visual image, and motion effects which are constructed in advance, are applied to motion simulation. Motion effects which occur during interaction between the user and the exhibition system can be easily added. Various sensory cues that are appropriate to the exhibition system are also considered.

• Journal of the Korea Society of Computer and Information
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• v.4 no.3
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• pp.93-100
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• 1999

In this Paper. Multi-channels L-Expressnet protocol is proposed by supplementing multi-channels control method. This protocol is proposed to complement the shortcomings of the basic protocol which is used for the medium access in LAN. We analyzed the protocol in channel utilization viewpoint and compared the result with that of the Expressnet and L-Expressnet protocol. From this result, we showed that the channel utilization or the Multi-channels L-Expressnet Protocol is superior to that of the other medium access control methods when the channel traffic is increased.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.2
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• pp.390-407
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• 2011

Three-dimensional (3D) video technologies are becoming increasingly popular, as it can provide users with high quality and immersive experiences. However, color inconsistency between the camera views is an urgent problem to be solved in multi-view imaging. In this paper, a perception-based color correction method for multi-view images is proposed. In the proposed method, human visual sensitivity (VS) and visual attention (VA) models are incorporated into the correction process. Firstly, the VS property is used to reduce the computational complexity by removing these visual insensitive regions. Secondly, the VA property is used to improve the perceptual quality of local VA regions by performing VA-dependent color correction. Experimental results show that compared with other color correction methods, the proposed method can greatly promote the perceptual quality of local VA regions greatly and reduce the computational complexity, and obtain higher coding performance.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.375-378
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• 2005

The multi-view video is a collection of multiple videos capturing the same scene at different viewpoints. The multi-view video can be used in various applications, including free viewpoint TV and three-dimensional TV. Since the data size of the multi-view video linearly increases as the number of cameras, it is necessary to compress multi-view video data for efficient storage and transmission. The multi-view video can be coded using the concept of the layered depth image (LDI). In this paper, we describe a procedure to generate LDI from the natural multi-view video and present a method to encode multi-view video using the concept of LDI.

• Journal of architectural history
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• v.24 no.3
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• pp.17-29
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• 2015

This study is about the change of multi-storied buildings in Hanyang, the capital city of Joseon Dynasty. The changes are divided into 3 phases in the viewpoint of architectural types and building types. The first phase is from the early Joseon Dynasty to the time of Japanese invasion to Korea and Sungryemun remains until now. The second phase is from 1592 to the the first half of the 18th century. Many multi-storied Buddhist halls were rebuilt at that time. In the final phase, many multi-storied gate buildings and multi-storied main buildings of palaces were rebuilt. And there are differences between the Buddhist buildings and the main buildings of palaces. By the way the change that architectural style of the Buddhist buildings and the main buildings of pal were switched and mixed occurred. For example, Anguksa Daeungjeon adopted the style of multi-storied gates and Injeongjeon adopted the style of multi-storied Buddhist halls. These phenomenon was result from periodical situation the monk carpenter and his disciple took part in governmental construction like Janganmun.