• Title/Summary/Keyword: Media Access Control

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A Development of Access Management System Server Based on Smartphone (스마트폰 기반의 출입관리시스템 서버 개발)

  • Lim, Ji-yong;Oh, Am-suk;Kim, Gwan-Hyung
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2015.07a
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    • pp.325-326
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    • 2015
  • 본 논문은 스마트폰 기반의 출입관리시스템을 목표로 하며, 이를 위한 출입관리시스템 서버를 개발하였다. 출입관리시스템 서버에서는 자동개폐기를 제어하고 출입자의 권한관리, 출입 및 점검 이력 등 체계적인 출입관리를 한다. 그리고 자동개폐기 동작에 관한 상태정보를 스마트폰 앱으로 전송하여 원격지 서버에서의 실시간 모니터링을 제공한다.

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Design and Implementation of variable TDMA MAC Protocol of WDM method on Ethernet PON Using OPNET (OPNET을 이용한 Ethernet PON에서의 WDM 방식의 가변 TDMA MAC 프로토콜의 설계 및 구현)

  • 정민석;장용석;엄종훈;조정현;김승호
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.04d
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    • pp.608-610
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    • 2003
  • Ethernet PON(Passive Optical Network)에서 핵심 기술 중의 하나인 MAC(Media Access Control) 프로토콜은 ONU(Optical Network틴nit)들이 상향으로 트래픽을 전송할 때 공유되어 있는 링크상의 충돌을 방지하고, 효율적인 대역폭을 할당하기 위한 스케줄링 알고리즘을 포함하고 있다. 본 논문에서는 차세대 가입자 망인 Ethernet PON에서 상향으로의 대역폭 부족을 개선하기 위하여, n개의 파장을 사용한 가변 슬롯 할당 TDMA(Time Division Multiple Access) 방식의 MAC 프로토콜을 제안한다. 이를 검증하기 위하여 OPNET 시뮬레이션 도구를 이용해 Ethernet PON 모델을 설계하고 시뮬레이션 한다.

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Dynamic Characteristic Analysis and Position Control for High Density Optical Head Using Bimorph PZT (고밀도 광학헤드를 위한 Bimorph 압전 액추에이터의 동특성 해석 및 위치제어)

  • Park, Tae-Wook;Park, No-Cheol;Yang, Hyun-Seok;Park, Young-Pil;Kwon, Young-Ki
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.1 s.94
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    • pp.12-19
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    • 2005
  • This paper proposed a dual actuator using Bimorph PZT for information storage device based on prove array NSOM(near-field scanning optical microscopy). The gap between the media and the optical head should be maintained within the optical tolerance. Therefore, a new actuator having high sensitivity is required. Bimorph PZT, which has fast access time and high sensitivity characteristic, is suitable for this precise actuating system. This paper is focused on derivation of mathematical model of dual Bimorph PZT actuator and control algorithm. Hamilton's principle was used for mathematical model. The model is verified by FEA(finite element analysis), and compared with experimental results. Different control algorithms were used for two Bimorph PZT actuating same direction and opposite direction. The gap between recording media and optical head was controlled within 20nm in experiment.

Access to Anti-smoking Information among School Children and its Potential Impact on Preventing Smoking Initiation: Results from the Global Youth Tobacco Use Survey (GYTS) 2014 in Viet Nam

  • Hoang, Van Minh;Kim, Bao Giang;Phan, Thi Hai;Trinh, Dinh Hoang;Doan, Thu Huyen;Luong, Ngoc Khue;Nguyen, Thuy Linh;Nguyen, Tuan Lam;Pham, Thi Quynh Nga
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup1
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    • pp.31-36
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    • 2016
  • Scientific evidence on all aspects of smoking amongst youth is very important for designing appropriate interventions to reduce smoking among this vulnerable population. This paper describes current access to anti-smoking information among school children aged 13 to 15 years in Vietnam in 2014 and examines its potential impact on preventing smoking initiation. The data used in this paper were obtained from the 2014 Global Youth Tobacco Survey (GYTS) in Vietnam. Students were asked questions about their level of awareness of anti-smoking information from various sources in the past 30 days and about lessons in school regarding the dangers of tobacco use during the last 12 months. Those who have never smoked were asked "whether or not they thought about avoiding cigarettes because of health warnings on cigarette packages" and answers were analyzed in combination with data on access to anti-smoking information from other sources. The prevalence of exposure to antismoking campaigns was high among school children in Viet Nam: 55.3% of current smokers reported thoughts of smoking cessation because of health warnings on cigarette packages; 60.5% of never smokers avoided initiating smoking because of the same health warnings. The potential impact of graphic health warnings to prevent school-aged children from smoking initiation would be stronger if there was concurrent access to anti-smoking programs on the dangers of tobacco use in schools. However, school education for tobacco prevention and control has not been as strong as expected. A more comprehensive school curriculum on tobacco prevention and control is recommended to reinforce antismoking messages among school children.

A Fault-tolerant Network-based Mobility Management Scheme for Supporting Multi-media Services (방통융합 멀티미디어 서비스를 제공하기 위한 안정된 네트워크 기반의 이동성 관리 기술)

  • Lee, Sung-Kuen;Lee, Kyoung-Hee;Hong, Kang-Woon;Um, Tai-Won;Lee, Hyun-Woo;Ryu, Won;Park, Jin-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.3B
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    • pp.526-535
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    • 2010
  • In this paper, we propose the fault-tolerant network-based mobility management scheme for supporting multimedia services of broadcasting & communications convergence in fixed mobile convergence (FMC) networks. The proposed scheme is based on AIMS (Access Independent Mobility Service) which is developed for the mobility support among heterogeneous access networks. To support stable location management and handover control for a MN, the proposed scheme supports stable management of binding information by sensing network attachment and detachment of a mobile node (MN). In addition, the proposed fault-tolerant (FT) AIMS supports a function of message retransmission for the support of handover control message and a function of heartbeat message transmission for the support of stable access network environments to a mobile node. We evaluate and analyze the performance of the proposed scheme through the implementation of AIMS system test-bed.

The Mouse & Keyboard Control Application based on Smart Phone (스마트 폰 기반의 마우스와 키보드 제어 어플리케이션)

  • Lim, Yang Mi
    • Journal of Korea Multimedia Society
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    • v.20 no.2
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    • pp.396-403
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    • 2017
  • In recent years, the use of touch screens has expanded, and devices such as remote controllers have been developed in various ways to control and access contents at long range. The wireless-based touch screen is used in classroom, seminar room, and remote video conversation in addition to the TV remote control. The purpose of the study is to design a smart phone-based intuitive interface that can perform the role of a wireless mouse and a wireless keyboard at range using Bluetooth and to develop an application that integrates functions of a mouse and a keyboard. Firstly, touch interaction model for controlling software such as PowerPoint by connecting to a general PC on a smart phone has been studied. The most simple touch operation interface is used to reproduce the function of existing devices and design more simply. The studies of the extension of interfaces with various functions are important, but development of optimized interfaces for users will become more important in the future. In this sense, this study is valuable.

Design and Implementation of a Stereoscopic Image Control System based on User Hand Gesture Recognition (사용자 손 제스처 인식 기반 입체 영상 제어 시스템 설계 및 구현)

  • Song, Bok Deuk;Lee, Seung-Hwan;Choi, HongKyw;Kim, Sung-Hoon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.3
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    • pp.396-402
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    • 2022
  • User interactions are being developed in various forms, and in particular, interactions using human gestures are being actively studied. Among them, hand gesture recognition is used as a human interface in the field of realistic media based on the 3D Hand Model. The use of interfaces based on hand gesture recognition helps users access media media more easily and conveniently. User interaction using hand gesture recognition should be able to view images by applying fast and accurate hand gesture recognition technology without restrictions on the computer environment. This paper developed a fast and accurate user hand gesture recognition algorithm using the open source media pipe framework and machine learning's k-NN (K-Nearest Neighbor). In addition, in order to minimize the restriction of the computer environment, a stereoscopic image control system based on user hand gesture recognition was designed and implemented using a web service environment capable of Internet service and a docker container, a virtual environment.

Dynamic CSMA Protocol Based on the Network Status (네트워크 상태에 따른 동적 CSMA 프로토콜)

  • Lee, Wang-Jong;Rhee, Seung-Hyong
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.7 no.2
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    • pp.70-80
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    • 2008
  • CSMA(Carrier Sense Multiple Access) is a media access control protocol when nodes use a shared channel. To reduce the probability of collision and increase the performance, the station lust checks the state of the channel. In this paper, we study the performance improvement method based on p-persistent strategy. The p-persistent method reduces the chance of collision and improves the efficiency. However, a probability p and the number of station affect the performance. This paper proposes a dynamic CSMA multiple access based on the network status. If the possibility of collision is low, the station increases the probability p to improve the performance. In the opposite case, the station decreases the probability p. Our simulation results show that the proposed scheme outperforms any methods of CSMA multiple access according to the current persistent strategy.

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A QoS-aware Time slot allocation Algorithm for Distributed MAC in UWB Wireless Personal Area Networks (UWB 분산 제어기반 WPAN MAC 에서 QoS를 고려한 시간 슬롯 할당 알고리즘의 제안)

  • Park, Ji-Seon;Hur, Kyeong;Eom, Doo-Seop
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.263-264
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    • 2008
  • 고속 무선 PAN(Personal Area Networks)기술은 10m 이내의 짧은 거리에서 고속으로 대용량의 데이터를 전송하기 위한 기술로, 최근 무선 USB(Wireless Universal Serial Bus)나 HDTV(High Definition TV)와 같은 광대역 멀티미디어 응용 시장을 겨냥한 연구가 IEEE 802.15.3과 WiMedia를 중심으로 활발히 진행되고 있다. [1] 본 논문에서는 WiMedia Alliance에서 제안한 Distributed Medium Access Control (D-MAC)에서 다수 스트림의 QoS 요구를 만족시키는 신뢰성 있는 전송을 위해 데이터 시간 슬롯을 효율적으로 할당하는 알고리즘에 대해 연구하고자 한다.

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Study on Protection and Access Control of Personal Bioinformation in Telemecine Environment (원격의료환경에서 개인생체정보 보호 및 무결성에 관한 연구)

  • Kim, Soon Seok;Lee, Jae Hyun
    • Smart Media Journal
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    • v.5 no.4
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    • pp.57-62
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    • 2016
  • By using personal health devices, a type of bio-censor at home and building, for telemedicine, this paper proposes a new method to protect more robust patient's privacy than before scheme [1] by ensuring the integrity and the secure transmission further when it communicates with gateway which collecting bio-information from them. As the suggested method is designed to conform with ISO/IEEE 11073-20601 [2], which is international standard, it considered interoperability with various health devices.