• 제목/요약/키워드: Link adaptation

검색결과 101건 처리시간 0.025초

A Hand Gesture Recognition Method using Inertial Sensor for Rapid Operation on Embedded Device

  • Lee, Sangyub;Lee, Jaekyu;Cho, Hyeonjoong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권2호
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    • pp.757-770
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    • 2020
  • We propose a hand gesture recognition method that is compatible with a head-up display (HUD) including small processing resource. For fast link adaptation with HUD, it is necessary to rapidly process gesture recognition and send the minimum amount of driver hand gesture data from the wearable device. Therefore, we use a method that recognizes each hand gesture with an inertial measurement unit (IMU) sensor based on revised correlation matching. The method of gesture recognition is executed by calculating the correlation between every axis of the acquired data set. By classifying pre-defined gesture values and actions, the proposed method enables rapid recognition. Furthermore, we evaluate the performance of the algorithm, which can be implanted within wearable bands, requiring a minimal process load. The experimental results evaluated the feasibility and effectiveness of our decomposed correlation matching method. Furthermore, we tested the proposed algorithm to confirm the effectiveness of the system using pre-defined gestures of specific motions with a wearable platform device. The experimental results validated the feasibility and effectiveness of the proposed hand gesture recognition system. Despite being based on a very simple concept, the proposed algorithm showed good performance in recognition accuracy.

DeNitrification-DeComposition (DNDC) Improvement through Model Coupling and Sub-model Development Considering Agricultural Land Use and Future Climate Change

  • Min, Hyungi;Hwang, Wonjae;Kim, Min-Suk;Kim, Jeong-Gyu
    • 환경생물
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    • 제35권1호
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    • pp.37-46
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    • 2017
  • Climate change is the biggest concern of the $21^{st}$ century. Greenhouse gas (GHG) emissions from various sectors are attracting attention as a cause of climate change. The DeNitrification-DeComposition (DNDC) model simulates GHG emissions from cropland. To study future GHG emissions using this simulation model, various factors that could change in future need to be considered. Because most problems are from the agricultural sector, DNDC would be unable to solve the factor-changing problem itself. Hence, it is necessary to link DNDC with separate models that simulate each element. Climate change is predicted to cause a variety of environmental disasters in the future, having a significant impact on the agricultural environment. In the process of human adaptation to environmental change, the distribution and management methods of farmland will also change greatly. In this study, we introduce some drawbacks of DNDC in considering future changes, and present other existing models that can rectify the same. We further propose some combinations with models and development sub-models.

차량 운전 시뮬레이터에서 모션과 영상의 동기화를 위한 알고리즘 및 구현 방안 (Motion and Image Matching Algorithms and Implementation for Motion Synchronization in a Vehicle Driving Simulator)

  • 김헌세;김대섭;김동환
    • 로봇학회논문지
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    • 제12권2호
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    • pp.184-193
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    • 2017
  • This work shows how to create an algorithm and implementation for motion and image matching between a vehicle simulator and Unity 3D based virtual object. The motion information of the virtual vehicle is transmitted to the real simulator via a RS232 communication protocol, and the motion is controlled based on the inverse kinematics solution of the platform adopting rotary-type six actuators driving system. Wash-out filters to implement the effective motion of the motion platform are adopted, and thereby reduce the dizziness and increase the realistic sense of motion. Furthermore, the simulator system is successfully designed aiming to reducing size and cost with adaptation of rotary-type six actuators, real driving environment via VR (Virtual Reality), and control schemes which employ a synchronization between 6 motors and 3rd order motion profiles. By providing relatively big sense of motion particularly in impact and straight motions mainly causing simulator sickness, dizziness is remarkably reduced, thereby enhancing the sense of realistic motion.

Clustering Ad hoc Network Scheme and Classifications Based on Context-aware

  • Mun, Chang-Min;Lee, Kang-Whan
    • Journal of information and communication convergence engineering
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    • 제7권4호
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    • pp.475-479
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    • 2009
  • In ad hoc network, the scarce energy management of the mobile devices has become a critical issue in order to extend the network lifetime. Current research activity for the Minimum Energy Multicast (MEM) problem has been focused on devising efficient centralized greedy algorithms for static ad hoc networks. In this paper, we consider mobile ad hoc networks(MANETs) that could provide the reliable monitoring and control of a variety of environments for remote place. Mobility of MANET would require the topology change frequently compared with a static network. To improve the routing protocol in MANET, energy efficient routing protocol would be required as well as considering the mobility would be needed. In this paper, we propose a new method, the CACH(Context-aware Clustering Hierarchy) algorithm, a hybrid and clustering-based protocol that could analyze the link cost from a source node to a destination node. The proposed analysis could help in defining the optimum depth of hierarchy architecture CACH utilize. The proposed CACH could use localized condition to enable adaptation and robustness for dynamic network topology protocol and this provide that our hierarchy to be resilient. As a result, our simulation results would show that CACH could find energy efficient depth of hierarchy of a cluster.

입각기.유각기 동시제어식 대퇴의지의 개발 (Development of a Stance and Swing Phase Control Transfemoral Prosthesis)

  • 김신기;김경훈;문무성;이순걸;백영남
    • 대한기계학회논문집A
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    • 제25권4호
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    • pp.685-694
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    • 2001
  • In this study, a transfemoral prosthesis system of which both stance phase and swing phase are controllable has been developed for the recovery of the biomechanical function of the amputated leg. It consists of a 5 bar link mechanism, a hydraulic-rubber knee damper for stance phase control and a pneumatic cylinder controlled via a microprocessor for stance phase control. The mechanical characteristics of the knee damper which absorbs the impact energy generated at the heel contact were investigated. The characteristics of the pneumatic cylinder essential for the speed adaptation of the prosthesis during swing phase were also studied for its mechanical characteristics. The prosthesis was subject to the clinical tests, and the gait characteristics obtained were very close to those of normal subjects. The stance and swing controlled prosthesis that were developed in this study showed good stability during the stance phase and showed good controllability during the swing phase.

제한된 입력 전압을 갖는 전기 구동 로봇 매니퓰레이터에 대한 분산 강인 적응 신경망 제어 (Decentralized Robust Adaptive Neural Network Control for Electrically Driven Robot Manipulators with Bounded Input Voltages)

  • 신진호;김원호
    • 한국소음진동공학회논문집
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    • 제25권11호
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    • pp.753-763
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    • 2015
  • This paper proposes a decentralized robust adaptive neural network control scheme using multiple radial basis function neural networks for electrically driven robot manipulators with bounded input voltages in the presence of uncertainties. The proposed controller considers both robot link dynamics and actuator dynamics. Practically, the controller gain coefficients applied at each joint may be nonlinear time-varying and the input voltage at each joint is saturated. The proposed robot controller overcomes the various uncertainties and the input voltage saturation problem. The proposed controller does not require any robot and actuator parameters. The adaptation laws of the proposed controller are derived by using the Lyapunov stability analysis and the stability of the closed-loop control system is guaranteed. The validity and robustness of the proposed control scheme are verified through simulation results.

Identification of a PAS Domain-containing Protein in a Mammalian Hibernator, Murina leucogaster

  • Cho, Sang-Gil;Kim, Dong-Yong;Eom, Ki-Hyuk;Bae, Ki-Ho
    • Animal cells and systems
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    • 제13권2호
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    • pp.119-125
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    • 2009
  • Mammalian hibernation is a type of natural adaptation that allows organisms to avoid harsh environment and to increase the possibility of survival. To investigate the molecular link between circadian and hibernating rhythms in the greater tube-nosed bats, Murina leucogaster, we set out to identify circadian genes that are expressed in bats, with specific focus on the PAS domain by using PCR-based screens. We could isolate a eDNA clone, designated as LPAS1, that encodes a protein of 521 amino acid residues. LPAS1 is closely related with CLOCK family with the highest homology to human CLOCK. Based on RT-PCR analyses, LPAS1 transcripts are ubiquitously present in tissues from both summer active and winter dormant periods. Given that LPAS1 is a member of the bHLH-PAS protein superfamily but lacks polyglutamine transactivation domains, it is likely to function as a repressor for endogenous CLOCK to hinder its roles in promoting transcription. Our result will open a new avenue to further examine the functional interconnection between the circadian clock and the circannual clock such as mammalian hibernation.

유비쿼터스 환경에서 다중 인터페이스를 탑재한 이동 단말의 인터페이스 선택 기법에 관한 연구 (A Study on the Interface Selection Scheme of Mobile Nodes with Multiple Interfaces in Ubiquitous Environments)

  • 김성철;문일영;조성준
    • 한국항행학회논문지
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    • 제14권2호
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    • pp.198-205
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    • 2010
  • 유비쿼터스 환경에서 사용자가 언제 어디서나 네트워크에 접속할 수 있도록 하기 위해 다중 인터페이스 기술에 대한 관심과 연구가 늘고 있다. 본 논문에서는 다중 인터페이스를 탑재한 이동 단말이 이동 중에 단일 인터페이스만 고정적으로 이용하지 않고, 계속해서 변화하는 무선 채널의 상태에 따라 적절한 인터페이스를 적응적으로 이용하기 위한 기법을 제안한다. 본 논문에서 제안하는 기법은 각 인터페이스의 전송률과 패킷 오류율, 그리고 종단간 지연시간에 따라 가장 적절한 무선 인터페이스를 판단할 수 있다. 시뮬레이션 결과 본 논문에서 제안한 기법이 쓰였을 때 단일 인터페이스만 사용한 환경보다 약 20% 더 많은 패킷 전송을 할 수 있었다.

입각기와 유각기 제어 대퇴의지의 개발 (Development of a Stance & Swing Phase Control Transfemoral Prosthesis)

  • 김신기;김종권;홍정화;김경훈;문무성;이순걸;백영남
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 추계학술대회논문집A
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    • pp.504-509
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    • 2000
  • In this study, a transfemoral prosthesis system of which stance phase and swing phase are controlled during walking has been developed for the recovery of the biomechanical function of the amputated leg. It consists of a 5 bar link mechanism, a hydraulic-rubber knee damper for stance phase control and a pneumatic cylinder controlled via a microprocessor for stance phase control. The mechanical characteristics and behaviour of the knee damper which absorbs the impact energy generated at the heel contact was investigated. The characteristics of the pneumatic cylinder essential for the speed adaptation of the prosthesis during swing phase was also studied for its mechanical characteristics. The prosthesis was subject to the clinical test ant the gait characteristics obtained were very close to those of normal. The stance and swing controlled prosthesis that were developed in this study showed good stability during the stance phase and showed good controllability during the swing phase.

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FMT 시스템에서 동기 오차와 잡음에 강인한 도플러 주파수 추정 기법 (Doppler Frequency Estimation Robust to Synchronization Error and Noise in FMT Systems)

  • 염재흥;조영훈
    • 한국통신학회논문지
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    • 제35권6C호
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    • pp.572-579
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    • 2010
  • Filtered multi-tone (FMT) 다중 경로 페이딩에 강인하고 보호 구간 없이 전송됨으로 이동 통신 시스템에 효율적 방식이다. 이동 통신 시스템은 채널 추정과 링크 적응 성능의 향상을 위해서 도플러 주파수 정보를 필요로 하지만 기존 도플러 주파수 추정 연구는 직교 분할 다중 접속 (OFDM)에 집중되었고 FMT 방식에서 수행되지 않았다. OFDM에서 기존 연구는 잡음 회피를 위해서 시간 영역에서 처리함으로 상당한 복잡도를 갖고 또한 수신기의 동기 오차를 고려하지 않는다. 본 논문은 동기 오차로 인하여 발생하는 시간 영역과 주파수 영역에서 자기 상관의 위상 성분을 제거함으로써 동기 오차와 잡음에 강인한 도플러 주파수 추정 기법을 제안한다. 제안 기법이 FMT 방식의 상용화 시스템인 TETRA enhanced data service (TEDS)에 적용될 때 정확한 도플러 주파수를 추정한다.