• Title/Summary/Keyword: 비동기식통신

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Cluster-based Continuous Object Prediction Algorithm for Energy Efficiency in Wireless Sensor Networks (무선 센서 네트워크에서 에너지 효율성을 위한 클러스터 기반의 연속 객체 예측 기법)

  • Lee, Wan-Seop;Hong, Hyung-Seop;Kim, Sang-Ha
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.8C
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    • pp.489-496
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    • 2011
  • Energy efficiency in wireless sensor networks is a principal issue to prolong applications to track the movement of the large-scale phenomena. It is a selective wakeup approach that is an effective way to save energy in the networks. However, most previous studies with the selective wakeup scheme are concentrated on individual objects such as intruders and tanks, and thus cannot be applied for tracking continuous objects such as wild fire and poison gas. This is because the continuous object is pretty flexible and volatile due to its sensitiveness to surrounding circumferences so that movable area cannot be estimated by the just spatiotemporal mechanism. Therefore, we propose a cluster-based algorithm for applying the efficient and more accurate technique to the continuous object tracking in enough dense sensor networks. Proposed algorithm wakes up the sensors in unit cluster where target objects may be diffused or shrunken. Moreover, our scheme is asynchronous because it does not need to calculate the next area at the same time.

Detection Performance of Noncoherent Radar: MIMO Radar, Phased Array Radar, Directional MIMO Radar (비동기식 레이더의 검출 성능 비교: MIMO 레이더, 위상 배열 레이더, 지향성 MIMO 레이더)

  • An, Chan-Ho;Yang, Jang-Hoon;Pak, Ui-Young;Ryu, Young-Jae;Han, Duk-Chan;Kim, Dong-Ku
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.12B
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    • pp.1752-1757
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    • 2011
  • In a traditional phased array radar, closely spaced antenna elements transmit a scaled version of single waveform to maximize the signal energy. On the contrary, a multiple-input multiple-output (MIMO) radar consists of widely separated antennas and transmits an arbitrary waveform from each antenna element. These waveforms and spatial diversity enable superior capabilities compared with phased array radar. At high signal-to-noise ratio (SNR), the detection performance of the MIMO radar is better than the phased array radar due to the diversity gains. However, the phased array radar outperforms the MIMO radar at low SNR, due to the energy maximization. In this paper, we investigate the compromised scheme between the MIMO radar and the phased array radar. Employing the MIMO radar equipped with phased array elements, the compromised scheme achieves both array gain and diversity gain. Also, we compare the performance degradation when the steering direction is incorrect.

Soft And Timely Encourgement by AI with Behavior Modification Therapy to Help Middle-Aged Obesity (중년비만 관리를 위한 행동수정요법과 인공지능 기법을 활용한 유연하고 상황에 맞는 격려 방법에 대한 연구)

  • Jung, Hee Young;Choi, Ki-Won;Hong, Soo-Young;Kim, Hee-Cheol;Kim, Dae-Young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.05a
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    • pp.730-732
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    • 2017
  • While the short term effect of diet and exercise therapy has been proven, there has still been a problem of its long term effect. So, researchers has utilized behaviour modification therapy. It is expected to lead to natural weight loss by modifying wrong dietary life patterns and practices. However, this approach has turned out to be a more effective method for weight maintenance than loss of weight. In spite of its strength, as a matter of fact, persistent and continuous effort for weight management has not worked properly. This study proposes an artificial intelligence approach with the advantages of behaviour modification therapy, overcoming current approaches which is goal-driven and too uniform. For this, we plan to develop a health management program in which users get the messages that are customized for themselves according to different situations so that it can promotes persistent effort for exercise. Here, customized messages are handled by AI techniques, which eventually promotes soft persuasion, encouragement, and motivation.

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A Study of design Asyn communication eletronic cash protocol and system using PSTN/leased line (PSTN/전용선을 이용한 비동기 통신방식의 전자지불 프로토콜과 시스템 설계연구)

  • Kim, Whi-Young
    • Proceedings of the Korea Information Processing Society Conference
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    • 2002.04b
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    • pp.1563-1566
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    • 2002
  • The increase of vehicles stagnations leads to the increasing attention to the way customers pay and a large number of projects on electronic cash system. Tranport system is comprised of a number of advanced technologies, including information processing, communications, control, and electronics. Recently many research on a system which provides contact in order to protect driver is vehicle passage have been carried out. And some potential problems from that system are being reviewed by electronic cash system. In this papers, we suggest RF protocol developing technology using the concept of electronic cash. ATM electronic cash developing is consist of component of pre-developed coin throw, integration of component using its, and production of more requirement-satisfactory ITS solution. Result increase $15{\sim}40%$ pre-type vehicles stagnations. Especially, we expect this proposed concept would be well adapted to our national environments.

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Validation Testing Tool for Light-Weight Stream Ciphers (경량 스트림 암호 구현 적합성 검증 도구)

  • Kang Ju-Sung;Shin Hyun Koo;Yi Okyeon;Hong Dowon
    • The KIPS Transactions:PartC
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    • v.12C no.4 s.100
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    • pp.495-502
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    • 2005
  • Cryptographic algorithm testing is performed to ensure that a specific algorithm implementation is implemented correctly and functions correctly. CMVP(Cryptographic Module Validation Program) of NIST in US is the well-known testing system that validates cryptographic modules to Federal Information Processing Standards (FIPS). There is no FIPS-approved stream cipher, and CMVP doesn't involve its validation testing procedure. In this paper we provide validation systems for three currently used light-weight stream ciphers: Bluetooth encryption algorithm E0, 3GPP encryption algorithm A5/3, and RC4 used for WEP and SSL/TLS Protocols. Moreover we describe our validation tools implemented by JAVA programing.

A Design of Non-Coherent CMOS IR-UWB Receiver (비동기식 CMOS IR-UWB 수신기의 설계 및 제작)

  • Ha, Min-Cheol;Park, Young-Jin;Eo, Yun-Seong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.9
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    • pp.1045-1050
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    • 2008
  • In this paper presents a CMOS RF receiver for IR-UWB wireless communications is presented. The impulse radio based UWB receiver adopts the non-coherent demodulation that simplifies the receiver architecture and reduces power consumption. The IR-UWB receiver consists of LNA, envelop detector, VGA, and comparator and the receiver including envelope detector, VGA, and comparator is fabricated on a single chip using $0.18{\mu}m$ CMOS technology. The measured sensitivity of IR-UWB receiver is down to -70 dBm and the BER $10^{-3}$, respectively at data rate 1 Mbps. The current consumption of IR-UWB receiver except external LNA is 5 mA at 1.8 V.

Mutual-Backup Architecture of SIP-Servers in Wireless Backbone based Networks (무선 백본 기반 통신망을 위한 상호 보완 SIP 서버 배치 구조)

  • Kim, Ki-Hun;Lee, Sung-Hyung;Kim, Jae-Hyun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.1
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    • pp.32-39
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    • 2015
  • The voice communications with wireless backbone based networks are evolving into a packet switching VoIP systems. In those networks, a call processing scheme is required for management of subscribers and connection between them. A VoIP service scheme for those systems requires reliable subscriber management and connection establishment schemes, but the conventional call processing schemes based on the centralized server has lack of reliability. Thus, the mutual-backup architecture of SIP-servers is required to ensure efficient subscriber management and reliable VoIP call processing capability, and the synchronization and call processing schemes should be changed as the architecture is changed. In this paper, a mutual-backup architecture of SIP-servers is proposed for wireless backbone based networks. A message format for synchronization and information exchange between SIP servers is also proposed in the paper. This paper also proposes a FSM scheme for the fast call processing in unreliable networks to detect multiple servers at a time. The performance analysis results show that the mutual backup server architecture increases the call processing success rates than conventional centralized server architecture. Also, the FSM scheme provides the smaller call processing times than conventional SIP, and the time is not increased although the number of SIP servers in the networks is increased.