• Journal of Digital Convergence
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• v.10 no.4
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• pp.265-270
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• 2012

The subscriber access network is cause of the bottleneck phenomenon because equipment and infrastructure were not originally designed for busty high-bandwidth traffic between MAN(Metro Area Network) and LAN(Local Area Network). Whether riding on shorter copper drops or optical fiber, Ethernet is emerging as the future broadband protocol of choice, offering plug and play simplicity, and low cost. EPON(Ethernet Passive Optical Network) combines point-to-multipoint optical infrastructure with low-cost high-bandwidth Ethernet. The future broadband access network will be a combination of point-to-point and point-to-multipoint Ethernet, optimized for transporting IP data, as well as time critical voice and video. EPON is being considered as a novel communications infrastructure for next-generation broadband access network for the convergence of low-cost Ethernet equipment and low-cost fiber infrastructure. But, EPON has a problem with duplex multimedia services. It is the insufficiency of bandwidth for upstream. Because all ONUs use a shared transmission media for upstream. In this paper, we addressed the problem of upstream bandwidth in EPONs. We presented a wavelength division EPON supporting QoS in the differentiated services framework.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.231-231
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• 2008

최근 인터넷의 보급과 함께 고화질 및 양방향 TV, VOD 방송, 화상 전화 등의 멀티미디어 시대가 열리면서 초고속 통신 시스템에 대한 관심이 증가되고 있다. 특히 화상이나 동영상 같은 대량의 정보가 졸은 품질 및 빠른 속도로 전달될 수 있는 통신 시스템의 필요성이 대두됨에 따라 가장 효율적인 고속 전송 수단으로 광통신이 이용되고 있으며 그에 따른 광통신 능 수동 소자 개발에 관한 연구도 활발히 이루어지고 있다. 이러한 광통신 소자 중 원하는 빛을 선택적으로 투과하고 반사할 수 있는 flat-band pass(FP) filter의 역할이 중요한 부분을 차지하고 있다. 본 논문에서는 IR 영역에서 투과성이 우수한 칼코게나이드 물질을 이용해 l 차원 광자결정구조의 FP-filter를 설계, 제작하고 그에 대한 특성을 평가하였다. 시료는 5N의 순도를 갖는 As, Se, Te 물질을 준비하고 $As_xSe_yTe_z$를 조성비에 맞추어서 석영관에 진공 봉입한 후 용융 혼합하여 $As_{33}Se_{67}$과 $As_{40}Se_{25}Te_{35}$ 조성의 두 가지 비정질 벌크를 제작하였다. 제작된 시료의 굴절률은 ellipsometer을 사용하여 측정하였고, 본 연구진이 자체 개발한 계산툴에 따라 다중층막 구조를 설계하였다. 열 증착법을 이용하여 설계된 구조에 맞게 기판에 올리는 방법으로 1차원 광자결정 구조의 다중층막 샘플을 제작하였고 UV-Vis-IR Spectroscopy를 사용하여 반사도와 투과도를 측정하였다. 광통신용 L/C 밴드 주파수 범위에서 투과성이 우수한 칼코게나이드 박막의 1차원 광자결정 구조는 FP-filter등의 소자로써 유용하게 사용될 수 있다.

• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.137-144
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• 2007

Advances in networking technology digital media, and codecs have made it possible for the Internet evolves into a Broadband convergence Network (BcN) and provides various services including Voice over Internet Protocol (VoIP) and IPTV over their high-speed IP networks. In order for the Internet to make a profit as traditional Public Switched Telephone Network (PSTN), it must provide high qualify VoIP services. Therefore, real time qualify measurement framework is the most important requisite to provide VoIP service. For this, IETF (Internet Engineering Task Force) defined RTCP-Extended Reports (RTCP-XR) that extend RTCP (Real-Time Transport Protocol Control Protocol). However, procedure and method tot actually VoIP qualify measurement did not recommended nothing but defined item to measure voice quality. Our objective in this paper is to describes a practical measuring framework for end-to-end QoS of switched voice packet in an IP environment. It includes concepts as well as step-by-step procedures for measuring packetized voice streams. It also proposes new formats that extend RTCP-XR's concept.

• Broadcasting and Media Magazine
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• v.11 no.4
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• pp.118-131
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• 2006

With rapid development in ultra fast communication and digital multimedia, the realistic broadcasting technology, that can stimulate five human senses beyond the conventional audio-visual service is emerging as a new generation broadcasting technology. In this paper, we introduce a haptic broadcasting system and related core system and component techniques by which we can 'touch and feel' objects in an audio-visual scene. The system is composed of haptic media acquisition and creation, contents authoring, in the haptic broadcasting, the haptic media can be 3-D geometry, dynamic properties, haptic surface properties, movement, tactile information to enable active touch and manipulation and passive movement following and tactile effects. In the proposed system, active haptic exploration and manipulation of a 3-D mesh, active haptic exploration of depth video, passive kinesthetic interaction, and passive tactile interaction can be provided as potential haptic interaction scenarios and a home shopping, a movie with tactile effects, and conducting education scenarios are produced to show the feasibility of the proposed system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.627-630
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• 2009

The combination of the marine use various multi sensor surveillance system technology with the development of servo motion control algorithm and gyro sensor in six freedom motion is implemented to analyze the movement response. The stabilization of the motion control is developed and Nano driving Precision Pan-Tilt/Gimbal system is obtained from the security positioning cameras with ultra high speed device is used to carry out the exact behavior of the device. The exact behavior will be used to make a essential equipment. Finally the development of the Nano Driving Multi Sensor, Nano of Surveillance System Driving Precision Pan-Tilt/Gimbal optimal design and production, 3-aix Gyro Sensor based with Servo Motion Control algorithm development, Image trace video software and hardware tracking the development is organized and discuss in details. The development of the equipment and the system integration are fully experimented and verified.

• Management & Information Systems Review
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• v.28 no.3
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• pp.191-210
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• 2009

Internet was first designed only for sending data, but as the time passed, internet started to evolve into a broadband multi-media web that is capable of transmitting sound, video, high-capacity data and more due to the demands of internet users and the rapid changing internet-communication technology. Domestically, in January, 2000 Saerom C&T, launched a free VoIP, but due to limited ways of conversation(PC to PC) and absence of a revenue model, and bad speech quality, it had hit it's growth limit. This research studied VoIP based on technological enhancement in super-speed internet. According to IDC, domestic internet market's size was 80,800 million in 2008, and it formed a percentage of 12.5% out of the whole sound-communication market. in case of VoIP, it is able to maximize it's profit by connecting cable and wireless network, also it has a chance of becoming firm-concentrated monopoly market by fusing with IPTV. Considering the fact that our country is insignificant in MVNO revitalization, regulating organizations will play a significant roll on regulating profit between large and small businesses. Further research should be done to give VoIP a secure footing to prosper and become popularized.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.9
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• pp.1093-1098
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• 2013

A single-crystal sapphire is used as a transparent bulletproof window material; however, few studies have investigated the dynamic behavior and fracture properties under high-speed impact. High-speed and high-resolution sequential images are required to study the interaction of the bullet with the brittle ceramic materials. In this study, a device is developed to capture the sequence of high-speed impact/penetration phenomena. This system consists of a speed measurement device, a microprocessor-based camera controller, and multiple CCD cameras. By using a linear array sensor, the speed-measuring device can measure a small (diameter: up to 1 2 mm) and fast (speed: up to Mach 3) bullet. Once a bullet is launched, it passes through the speed measurement device where its time and speed is recorded, and then, the camera controller computes the exact time of arrival to the target during flight. Then, it sends the trigger signal to the cameras and flashes with a specific delay to capture the impact images sequentially. It is almost impossible to capture high-speed images without the estimation of the time of arrival. We were able to capture high-speed images using the new system with precise accuracy.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04b
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• pp.727-730
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• 2001

초고속 인터넷 서비스의 확대에 따라 이를 교육에 직 간접적으로 응용하기 위한 노력이 지속적으로 진행되어 왔다. 특히 웹 기반의 가상강의 저작도구를 통한 웹 코스웨어는 원거리 학습자들의 학습 욕구를 자기 주도적인 학습을 통해 가능케 했고 기존의 텍스트, 사운드를 통한 가상강의에서 동영상이 가미된 주문형 교육 서비스(EOD: Education On Demand)가 가능해졌다. 그러나 이를 이용하는 학습자는 전체적인 모듈의 이해를 통해 수업이 진행됨에 따라 학습과정에서는 질의응답을 튜터를 통해 웹 캐스팅이 이루어졌다. 따라서, 질의응답은 텍스트 형식의 E-mail, 채팅, 게시판, 방명록을 통해 이루어지므로 학습자가 요구한 질의 내용을 잘못 이해하고 튜터가 학습 과정에서의 피드백을 제공하지 못함으로써 개인 학습의 동기부여가 감소됨에 따라 흥미를 잃게 되었다. 본 논문에서는 이러한 문제점을 개선하기 위해 멀티 캐스팅 기법을 통해 교육용 서버를 이용한 학습지원도구를 분석, 설계한다. 가상강의는 기본적인 컨텐츠를 제시하고 그를 통해 수업이 진행되는 과정에서의 질의응답을 일대다(One-To-Many)의 멀티 캐스팅 서비스를 튜터가 지정한 교육용 서버를 통해 텍스트 형식이 아닌 강의자료로 쓰인 문서 파일에 직접 작성하여 전송하게 된다. 따라서 튜터는 메일링 서비스를 통해 질문사항을 자신의 폴더 서비스로 확인하고 즉시 학습자에게 피드백을 제공함으로써 튜터와 학습자들간의 커뮤니케이션이 활발히 이루어지며, 상호작용의 증가를 통해 웹 기반의 컨퍼런싱(WBC: Web Based Conferencing)을 가질 수 있게 된다.rver는 Client가 요청한 Content(services)를 전달 해 주는 컨텐트 전달 모듈(Content Deliver Module)과 서버 Phonebook 엑세스 모들(Server Phonebook Access Module)로 구성되어 있다.외 보다 높았다(I/O ratio 2.5). BTEX의 상대적 함량도 실내가 실외보다 높아 실내에도 발생원이 있음을 암시하고 있다. 자료 분석결과 유치원 실내의 벤젠은 실외로부터 유입되고 있었고, 톨루엔, 에틸벤젠, 크실렌은 실외뿐 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.28 no.2
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• pp.89-95
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• 2017

Background and Objectives : High-speed videolaryngoscopy (HSV) is the only technique that captures the true intra-cycle vibratory behavior of the vocal folds by capturing full images of the vocal folds. However, it has problems of no immediate feedback during examination, considerable waiting time for digital kymography (DKG), recording duration limited to a few seconds, and extreme demands for storage space. Herein, we demonstrate a new post-processing method that converts HSV images to two-dimensional digital kymography (2D-DKG) images, which adopts the algorithm of 2D videokymography (2D VKG). Materials and Methods : HSV system was used to capture images of vocal folds. HSV images were post-processed in Kay image-process software (KIPS), and conventional DKG images were retrieved. Custom-made post-processing system was used to convert HSV images to 2D-DKG images. The quantitative parameters of the post-processed 2D-DKG images was validated by comparing these parameters with those of the DKG images. Results : Serial HSV images for all phases of vocal fold vibratory movement are included. The images were converted by the scanning method using U-medical image-process software. Similar to conventional DKG, post-processed 2D DKG image from the HSV image can provide quantitative information on vocal fold mucosa vibration, including the various vibratory phases. Differences in amplitude symmetry index, phase symmetry index, open quotient, and close quotient between 2D-DKG and DKG were analyzed. There were no statistical differences between the quantitative parameters of vocal fold vibratory movement in 2D-DKG and DKG. Conclusion : The post-processing method of converting HSV images to 2D DKG images could provide clinical information and storage economy.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.39-52
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• 2006

As accelerates the technical evolution of high-speed network and progresses the digitalization of broadcasting network, TV channel service through satellite/cable/terrestrial networks becomes more stable and mature. However, TV channel service using IP network such as IPTV is recently emerging. Especially, when it comes to current mosaic EPG(Electronic Program Guide) as a channel guide, the implementation of EPG via IP network is under developing. Furthermore, the personal target mosaic EPG is not provided at all in the IPTV. This paper proposes a construction method of mosaic system which can support fixed and personalized mosaic EPG using IP network for viewers. The fixed mosaic EPG is made several steps as follows ; First, H/E generates several mosaic A/V streams. Then, which are transmitted to the STB in terms of multicasting via IP network. Finally, mosaic EPG is displayed on TV through STB. In addition, this paper describes a construction model of the personalized A/V mosaic EPG that represents each person's favorite channels according to their tastes and interests. As for the contributions. The TV channel guide using IP network enable viewer to select channel more easily with practical adaptation of multi-channel expansibility and sufficient usability. In addition, through personal mosaic EPG, a number of viewers can compose their own mosaic EPG and enjoy a variety of channel easily in accordance with their preferences. Finally, the personal mosaic EPG can prohibit non-adult users from connecting adult-only contents more efficiently.