• Journal of Korea Multimedia Society
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• v.15 no.10
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• pp.1212-1220
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• 2012

In this paper, a collision-free resource reservation scheme for WUSB (Wireless Universal Serial Bus) networks with WiMedia D-MAC (Distributed Medium Access Control). Since distributed characteristic of the WiMedia D-MAC supporting DRP (Distributed Reservation Protocol) scheme may cause lots of conflicts, overall performances of the WUSB with WiMedia D-MAC can be deteriorated. In addition, when we consider multi-hop environment, "mobile" hidden node problem due to mobility of WUSB devices can be happened, and it is a critical problem to mobile WUSB devices transceiving real-time QoS (Quality of Service) traffic. To tackle the problem, we propose a new DRP reservation mechanism to prevent DRP conflicts for multi-hop mobility support in WUSB networks with WiMedia D-MAC and show its improved performance via simulation results.

• Journal of Korea Multimedia Society
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• v.10 no.3
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• pp.373-380
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• 2007

In this paper we propose a new efficient authentication protocol that reduces overheads of computation for digital signature generation/verification on mobile devices in the Personal Area Network (PAN). In particular, we focus on eliminating the traditional public key operations on mobile devices without any assistance of a signature server. Moreover, the proposed protocol provides a simplified procedure for certificate status management to alleviate communication and computational costs on mobile devices in the PAN.

• Journal of Korea Multimedia Society
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• v.17 no.4
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• pp.405-412
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• 2014

Due to the popularity of mobile phones, Peer-to-Peer (P2P) content sharing in mobile phones is highly desirable, especially in a mobile data connection. In addition, there has been an increasing demand for content sharing applications for P2P communication in Android-based smartphones as ubiquitous mobile devices. However, due to wireless network limits, unstable characteristic and restricted storage space, mobile users confront challenges in establishing connections and sharing video frames with other users. To solve this issue, we propose an architectural design and implementation of key frame sharing application that uses Chord, a distributed lookup protocol to establish a content sharing platform for mobile devices, combined with the Chord SDK based on Android. Our proposed system enables users easily to share key information on video data in real-time over a wireless network without manual processing of devices which join or leave the group and cost associated with the 3G/4G network.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.953-960
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• 2018

In recently, eye blink recognition, and face recognition are very popular and promising techniques. In some cases, people can use the photos and face masks to hack mobile security systems, so we propose an eye blinking detection, which finds eyes through the proportion of human face. The proposed method detects the movements of eyeball and the number of eye blinking to improve face recognition for screen unlock on the mobile devices. Experimental results show that our method is efficient and robust for the screen unlock on the mobile devices.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1395-1403
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• 2016

In recent years, researches of security threats reported that various types of social engineering attack were frequently observed. In this paper, we propose secure keypad scheme for mobile devices. In our scheme, every edge of keypad is linked each other, and it looks like a sphere. With this keypad, users input their password using pre-selected grid pointer. Because of circulation of the keypad layout, even though the attacker snatch the user password typing motion through the human eyes or motion capture devices, attacker do not estimate the original password. Moreover, without the information of grid pointer position, the attacker do not acquire original password. Therefore, our scheme is resistant to password guessing attack.

• Journal of Korea Multimedia Society
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• v.25 no.9
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• pp.1307-1315
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• 2022

In this paper, we proposed and developed a new portable skin elasticity measuring device based on the indentation method using piezoelectric effect. The proposed device is designed to minimize the uncertainty caused by the layer structure of the skin when measuring the elasticity of the skin. And, we developed a piezoelectric-based thin-film pressure sensor that can measure quantitatively and quickly during repeated measurement as a device sensor. To confirm the effectiveness of the proposed measuring device, it was compared with the experimental results of the conventional measuring devices under the same experimental conditions, and statistical correlation analysis was performed between the experimental data of the proposed measuring device and the experimental data of the conventional measuring devices. As a result of the correlation analysis, it was confirmed that the proposed measuring device had a high correlation with the conventional measuring devices. Therefore, it was confirmed that the proposed skin elasticity measuring device was effective.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.827-832
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• 2001

기존 신호등 체계의 문제점을 보완하기 위해 센서를 이용하여 각 차로에 진행하려고 하는 차량을 감지하고, 대기 차량이 없을 경우 다음방향으로 신호를 주어 소통에 효율성을 높였으며 특히 GAL소자 하나로 설계함으로써 개발비용을 줄이도록 하였다.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.62-62
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• 2012

• Journal of Advanced Information Technology and Convergence
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• v.9 no.2
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• pp.55-63
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• 2019

Vehicle communication networks have some deficient network resources to support a vast multimedia service including safety driving information, video, news and some broadcast relayed from the playgrounds such as professional baseball games for autonomous vehicles. This paper deals with the framework for providing seamless multimedia service including safety driving information using multicast in cooperated-connected vehicle communication network (CVCN). It adopts smart-switch (SS) and smart intelligent multicast agent(SIMA) to support the seamless multimedia service. The SS manages and switches multimedia streams through SIMA in CVCN network. The SIMA to operate as an access point, is composed of multicast supporting part and control part of mobile devices/autonomous vehicles in CVCN network. Therefore this proposed technique using SS and SIMA within CVCN network is a new framework for multimedia service that can disperse the load of server.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.105-112
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• 2015

In this paper, we propose a simultaneously streaming method of multimedia files. The main features and contributions of the proposed method are as follows. First, to share and play at the same time one video playback in more than two devices to provide convenience for users. Second, to contribute communications and multimedia technologies by developing a streaming technology that can work on two or more devices. The results of implementation and performance evaluation show successful UDP data communication and the simultaneous transfer of streaming multimedia with data to the receiving sides.