• 제목/요약/키워드: Computer terminals

검색결과 244건 처리시간 0.035초

WiFi-Based Home IoT Communication System

  • Chen, Wenhui;Jeong, Sangho;Jung, Hoekyung
    • Journal of information and communication convergence engineering
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    • 제18권1호
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    • pp.8-15
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    • 2020
  • Internet-of-Things (IoT) technologies are used everywhere, and communication is one of its core and essential aspect. To solve the networking and communication of small IoT terminals, in this paper, a communication scheme based on low-cost WiFi is proposed, which also has the advantages of good compatibility and low power consumption. At the same time, it has a convenient one-key configuration mode, which reduces the technical requirements for operators. In this study, a communication protocol is designed that mainly aims at up to dozens of domestic IoT terminals, in which the amount of data is not large, data exchange is not high, and network is unstable. According to the alarm data, update data, and equipment or network fault, the protocol can respectively transmit in real time, regularly and repeatedly. This protocol is open and easy to integrate, and after cooperating with tiny encryption algorithm, information can be safely transmitted.

자동화 크레인 터미널을 위한 통신망에 관한 연구 (Communication Networks for Automated Crane Terminals)

  • 이경창;이석;이장명;이만형
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 1999년도 추계학술대회논문집
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    • pp.357-361
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    • 1999
  • Currently, many research projects are focusing on automation of various equipment such as cranes and AGV's for automated container terminals. However, for more productivity of these terminals, integration of the required equipment is most crucial as proved in Computer Integrated Manufacturing (CIM). The integration requires information exchange via a type of network interconnecting various pisces of equipment. In order to better design such networks, this paper presents the requirements, available protocols, and basic network structure for an communication network in an automated crane terminal

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효율적인 공공 자전거 재배치를 위한 실시간 자전거 수요량 기반의 HDPRA 기법 제안 (An Efficient Public Bicycle Reallocation using the Real-Time Bicycle on-Demand HDPRA Scheme)

  • 윤은옥;김강민;박혜성;정성욱
    • 한국정보전자통신기술학회논문지
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    • 제17권2호
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    • pp.83-92
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    • 2024
  • 현재 여러 나라에서 생활 속에서 편리하게 자전거를 이용할 수 있도록 자전거 대여 서비스를 제공하며 접근성을 늘리고 있다. 본 논문에서는 우리나라의 창원시 공공자전거 누비자 서비스를 소개하고 누비자 자전거의 수요와 공급의 불균형을 방지하기 위한 최우선 재배치 방법을 제안하고자 한다. 무작위로 터미널을 방문하여 재배치하는 알고리즘과 현재 위치에서 가장 짧은 거리에 있는 터미널을 방문하여 재배치하는 알고리즘을 제안한 방법과 비교하여 더 효율적임을 설명한다. 본 논문에서 제시하는 최우선 재배치 방법은 주위 터미널 중 수요가 가장 높고 거리가 가장 짧은 터미널부터 방문한다. 본 논문에서는 실험을 통하여 제안한 최우선 재배치 방법이 트럭이 운행한 총 거리 평균 817.44km로 가장 낮은 비용을 보이고, 대여 성공 평균 횟수 6437.45회, 88.14%로 가장 높아 두 알고리즘보다 우수함을 보여준다.

Providing Efficient Secured Mobile IPv6 by SAG and Robust Header Compression

  • Wu, Tin-Yu;Chao, Han-Chieh;Lo, Chi-Hsiang
    • Journal of Information Processing Systems
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    • 제5권3호
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    • pp.117-130
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    • 2009
  • By providing ubiquitous Internet connectivity, wireless networks offer more convenient ways for users to surf the Internet. However, wireless networks encounter more technological challenges than wired networks, such as bandwidth, security problems, and handoff latency. Thus, this paper proposes new technologies to solve these problems. First, a Security Access Gateway (SAG) is proposed to solve the security issue. Originally, mobile terminals were unable to process high security calculations because of their low calculating power. SAG not only offers high calculating power to encrypt the encryption demand of SAG's domain, but also helps mobile terminals to establish a multiple safety tunnel to maintain a secure domain. Second, Robust Header Compression (RoHC) technology is adopted to increase the utilization of bandwidth. Instead of Access Point (AP), Access Gateway (AG) is used to deal with the packet header compression and de-compression from the wireless end. AG's high calculating power is able to reduce the load on AP. In the original architecture, AP has to deal with a large number of demands by header compression/de-compression from mobile terminals. Eventually, wireless networks must offer users "Mobility" and "Roaming". For wireless networks to achieve "Mobility" and "Roaming," we can use Mobile IPv6 (MIPv6) technology. Nevertheless, such technology might cause latency. Furthermore, how the security tunnel and header compression established before the handoff can be used by mobile terminals handoff will be another great challenge. Thus, this paper proposes to solve the problem by using Early Binding Updates (EBU) and Security Access Gateway (SAG) to offer a complete mechanism with low latency, low handoff mechanism calculation, and high security.

On the Design of Optimal Response Time in Computer Terminal Networks

  • An Young-Ki
    • 한국국방경영분석학회지
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    • 제2권1호
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    • pp.185-194
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    • 1976
  • A terminal response time analysis for a general class of terminals-to-computer subsystem is presented in this paper. On the point of the front view, it should be considered for R.O.K. Military Defense to set up the communication network in order to facilitate for the currency of the information and the data communication system. The model used to study is based on the advanced data communications system in which terminals are connected to Terminal Control Units(TCU) that are in turn connected to local Front-End Processor(FEP). The line control procedures used to interface a TCU and an FEP may be half-duplex Binary Synchronous Communication(BSC), half-duplex Synchronous Data Link Control(SDLC), or full-duplex SLDC. This paper will contribute to facilitate the initial phase of system design and configuration for the Military Defense Communication Network System in future.

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무선 ATM 망을 위한 매체 전근 제어 프로토콜 설계 (Design of MAC protocol for Wireless ATM Networks)

  • 강용운;여현
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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    • pp.44-48
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    • 2000
  • In this study was modify the PRMA for supporting various types of traffic classes such as CBR, VBR, ABR and UBR. For uplink, we use reservation slots and so the performance will not degrade in case of over load conditions. For downlink broadcasting slots for informing the status of slot reservations are used so the high priority priority terminal can preempt. And we use almost same size buffer as the frame size. So we can dynamically deal with, the traffic changes of VBR terminals. It makes easy for the terminals to reserve supplementary slots. Each terminal is reallocated by the priority of traffic classes and so we can easily select the dropping packets in case of overload conditions. As a result, using our scheme, we can get high channel efficiency and get low packet dropping ratio and delay.

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이동통신 시스템에서 Cooperative Diversity를 위한 Partner Assignment Algorithm (Partner Assignment Algorithm for Cooperative Diversity in mobile communication systems)

  • 정영석;이재홍
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.81-82
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    • 2006
  • Most work on cooperative diversity has assumed that the cooperating group (source and partners) and the associated average channel conditions between terminals (source, partners, and destination) are predetermined. In practical situations, however, it is important to develop the efficient algorithms for assigning the terminals with good inter-user channels for cooperating groups. In this paper, we propose the partner assignment algorithm for cooperative diversity in mobile communication systems. The proposed partner assignment algorithm is investigated by using the path loss model for mobile communication systems. Numerical results show that the proposed partner assignment algorithm provides the comparable probability of cooperative transmission to the partner assignment algorithm using exhaustive search. The probability of cooperative transmission increases with the number of users, which gives potential benefits of practical implementation to user cooperation in mobile communication systems.

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고효율 Boost DC-DC 변환기를 위한 Line Regulation 향상에 대한 연구 (A Study On The Improved Line Regulation For High Efficiency BoostDC-DCConverter)

  • 두수연;정성연;정진일;곽계달
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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    • pp.391-392
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    • 2007
  • In recent, portable information and communication terminals such as a notebook computer, an electronic pocketbook, a hand personal computer(PC) have been regards as the leading role in the coming next generation portable multimedia terminals which have hi-directional wireless data communication capability and can receive information and communication services such as electronic mail, database searching, and electronic shopping at anytime and anyplace. Therefore, in this paper, the circuit is simulated by 0.35um memory process used Current Limit for Boost DC-DC converter. Supply voltage $2.5V{\sim}3.3V$, output voltage 5V, Clock Frequency 1MHz, output current 200mA and line regulation decreased 12.46%.

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Transmission Power Minimization with Network Coding for Mobile Terminals in Cellular Relay Networks

  • Du, Guanyao;Xiong, Ke;Li, Dandan;Qiu, Zhengding
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권9호
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    • pp.2098-2117
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    • 2012
  • This paper jointly investigates the bandwidth allocation, transmission strategy and relay positions for two-way transmission aware cellular networks with network coding (NC). Our goal is to minimize the transmission power of mobile terminals (MTs). Consider a cellular system, where multiple MTs exchange information with their common base station, firstly, we propose an efficient bandwidth allocation method and then give a transmission strategy for each MT to determine whether to use relay stations (RSs) for its two-way transmission with the BS or not. To further improve the system performance, the optimal positions of RSs are also jointly discussed. A GA-based algorithm is presented to obtain the optimum positions for RSs. Besides, the impacts of frequency reuse on MT's transmission power and system spectral efficiency (SE) under different number of relays are also discussed in our work. Numerical results show that the proposed NC aware scheme can extend MTs' battery life at least 6% more than traditional method.

Enhancing Location Privacy through P2P Network and Caching in Anonymizer

  • Liu, Peiqian;Xie, Shangchen;Shen, Zihao;Wang, Hui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제16권5호
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    • pp.1653-1670
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    • 2022
  • The fear that location privacy may be compromised greatly hinders the development of location-based service. Accordingly, some schemes based on the distributed architecture in peer-to-peer network for location privacy protection are proposed. Most of them assume that mobile terminals are mutually trusted, but this does not conform to realistic scenes, and they cannot make requirements for the level of location privacy protection. Therefore, this paper proposes a scheme for location attribute-based security authentication and private sharing data group, so that they trust each other in peer-to-peer network and the trusted but curious mobile terminal cannot access the initiator's query request. A new identifier is designed to allow mobile terminals to customize the protection strength. In addition, the caching mechanism is introduced considering the cache capacity, and a cache replacement policy based on deep reinforcement learning is proposed to reduce communications with location-based service server for achieving location privacy protection. Experiments show the effectiveness and efficiency of the proposed scheme.