• 제목/요약/키워드: Synchronize

검색결과 351건 처리시간 0.031초

Measurement Delay Error Compensation for GPS/INS Integrated Systems

  • Lim, You-chol;Joon Lyou
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.33.1-33
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    • 2002
  • The INS provides high rate position, velocity and attitude data with good short-term stability while the GPS provides position and velocity data with long-term stability. By integrating the INS with GPS, a navigation system can be achieved to provide highly accurate navigation performance. For the best performance, time synchronization of GPS and INS data is very important in GPS/INS integrated system. But, it is impossible to synchronize them exactly due to the communication and computation time-delay. In this paper, to reduce the error caused by the measurement time-delay in GPS/INS integrated systems, error compensation methods using separate bias Kalman filter are suggested for both the...

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The role of mitochondria in apoptosis

  • Jeong, Seon-Yong;Seol, Dai-Wu
    • BMB Reports
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    • 제41권1호
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    • pp.11-22
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    • 2008
  • Apoptosis (programmed cell death) is a cellular self-destruction mechanism that is essential for a variety of biological events, such as developmental sculpturing, tissue homeostasis, and the removal of unwanted cells. Mitochondria play a crucial role in regulating cell death. $Ca^{2+}$ has long been recognized as a participant in apoptotic pathways. Mitochondria are known to modulate and synchronize $Ca^{2+}$ signaling. Massive accumulation of $Ca^{2+}$ in the mitochondria leads to apoptosis. The $Ca^{2+}$ dynamics of ER and mitochondria appear to be modulated by the Bcl-2 family proteins, key factors involved in apoptosis. The number and morphology of mitochondria are precisely controlled through mitochondrial fusion and fission process by numerous mitochondria-shaping proteins. Mitochondrial fission accompanies apoptotic cell death and appears to be important for progression of the apoptotic pathway. Here, we highlight and discuss the role of mitochondrial calcium handling and mitochondrial fusion and fission machinery in apoptosis.

Method of DASH segments into a MMTP stream for switching contents under a hybrid broadcasting environment

  • Kang, Jeonho;Kang, Dongjin;Kim, Kyuheon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권12호
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    • pp.5981-5997
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    • 2017
  • Advanced Television Systems Committee (ATSC) produced ATSC 2.0 standard, which has been used for a HD/SD digital broadcasting service with MPEG-2 Transport Stream (TS) as a delivery protocol. Recently, users might want to consume multimedia services without being constrained by transport network. However, MPEG-2 TS is not suitable protocol for IP network. Thus, ATSC has enacted ATSC 3.0 standard, which is designed for a hybrid service through a conversion of both broadcasting and broadband channels. The ATSC 3.0 specifies delivery protocols as MPEG Media Transport (MMT) for a broadcasting environment and Dynamic Adaptive Streaming over HTTP (DASH) for a broadband. However, it seems difficult to combine broadcast and broadband for hybrid broadcasting, and it is difficult to synchronize media data between MMT and DASH. This paper suggests various new service scenarios to be brought up by a hybrid broadcasting, ATSC 3.0, and also proposes a stable mechanism for switching contents between different delivery protocols such as MMT and DASH.

CDR을 사용한 FPGA 기반 분산 임베디드 시스템의 클록 동기화 구현 (An Implementation of Clock Synchronization in FPGA Based Distributed Embedded Systems Using CDR)

  • 송재민;정용배;박영석
    • 대한임베디드공학회논문지
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    • 제12권4호
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    • pp.239-246
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    • 2017
  • Time synchronization between distributed embedded systems in the Real Time Locating System (RTLS) based on Time Difference of Arrival (TDOA) is one of the most important factors to consider in system design. Clock jitter error between each system causes many difficulties in maintaining such a time synchronization. In this paper, we implemented a system to synchronize clocks between FPGA based distributed embedded systems using the recovery clock of CDR (clock data recovery) used in high speed serial communication to solve the clock jitter error problem. It is experimentally confirmed that the cumulative time error that occurs when the synchronization is not performed through the synchronization logic using the CDR recovery clock can be completely eliminated.

동기화 운전을 통한 에너지 절약형 열차군 관리에 관한 연구 (A Study on the Control a Group of Trains for Energy Saving by Synchronized Driving)

  • 김경민
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.1159-1165
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    • 2010
  • This paper describes an energy efficient train control. In these days, the researchers develop the energy efficient railway technologies, such as energy storage system, energy efficient driving. Mass rapid transit (MRT) railways, which are an important means of public transportation in urban areas, have operational characteristics that include short headways, frequent departures and arrivals. Therefore, when multiple trains are operating in the same power supply system, it is important to synchronize the energy tractions and regenerations. This paper define the group of trains for energy saving according to a power supply. We analyze the current synchronized driving situations and estimate the effect.

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에일러론 링키지 해석을 통한 작동기 변위와 조종면 변위의 상관관계 규명 (Investigation of Kinematic Relation Between Actuator and Control Surface Deflection Using Aileron Linkage Analysis)

  • 이석천;이상종
    • 항공우주시스템공학회지
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    • 제6권3호
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    • pp.24-28
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    • 2012
  • An actuator should be added to a existing control linkage to make manned aircraft to unmanned. But it is quiet difficult to synchronize actuator with control surface because non-linear error necessarily occurs when four-bar linkage acts in three dimensional motion. In addition, in point of controller design view, while a real-time model needs the control surface deflection as its input, controller needs the actuator command as its output. Hence, the relation between both should be investigated. In this paper, the mathematical relation between actuator and control surface deflection investigated by kinematic analysis of a plant aircraft. The performance margin of the selected actuator also was verified.

광섬유 케이블을 이용한 콘크리트 구조물의 균열 탐사 (Crack Detection of Concrete Structures Using Optical Fiber Cables)

  • 조남소;김남식
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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    • pp.896-902
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    • 2000
  • Crack detection technique for concrete structures has been developed in this study,. The technique utilizes OTDR(Optical Time Domain Reflectometer) method that is widely used in the field of optical engineering. At present, some techniques, such as the naked eye inspection, inspection by crack gauge, ultra sonic detection and os on, are used for crack detection. However, these are not economical and are often time-consuming works. This method employs a common optical fiber as a means of crack detection. Th optical fiber is fully attached to concrete surface, and a crack on concrete could be detected to synchronize with the crack on optical fiber. The experimental verification was performed for concrete beams and the intial crack on the beam was detected under cracking force.

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CAN을 이용한 계층구조를 갖는 분산형 애니매트로닉스 시스템에 관한 연구 (Research on the multilayered animatronics system with CAN)

  • 이충호;장성룡;허욱열
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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    • pp.131-133
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    • 2007
  • The aninmatronics is a technique for representing animals or new kinds of living things like aliens with robots and machines. The motions of cameras and objects can be made complicatedly and finely by using various kinds of actuators. But it needs so many actuators to make complicated motions. To handle difficulty to synchronize actuators and to make a database of motions of actuators, the animatronics system that has layered structure with CAN is proposed. The system is devided by a three layers-PC, microcontrollers and actuators so that the problems which arise from using too many actuators such as management of data and time delay of processing data can be handled.

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피아노 연주 로봇의 개발 (Development of Piano Playing Robot)

  • 박광현;정성훈;;;변증남
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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    • pp.334-336
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    • 2007
  • This paper presents a beat gesture recognition method to synchronize the tempo of a robot playing a piano with the desired tempo of the user. To detect an unstructured beat gesture expressed by any part of a body, we apply an optical flow method, and obtain the trajectories of the center of gravity and normalized central moments of moving objects in images. The period of a beat gesture is estimated from the results of the fast Fourier transform. In addition, we also apply a motion control method by which robotic fingers are trained to follow a set of trajectories, Since the ability to track the trajectories influences the sound a piano generates, we adopt an iterative learning control method to reduce the tracking error.

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SRM의 정밀 각도제어를 위한 아날로그 엔코더 (Analog Encoder for Precise Angle Control of SRM)

  • 김태형;안영주;안진우
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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    • pp.667-670
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    • 2003
  • In a switched reluctance motor drive, it is important to synchronize the stator phase excitation with the rotor position, because the position of rotor is an essential information. In the high-speed region, switching angles are fluctuated back and forth out of\ the preset value, which is caused by the sampling period of the microprocessor. In this paper, a low cost analog encoder suitable for practical applications is proposed. The validity of the proposed analog encoder with a proper logic controller is verified from the experiments.

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