• Title/Summary/Keyword: Communication speed

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Technology development trend of the train network for high speed train (차세대 고속열차 통신네트워크 기술개발 동향)

  • Choi Kweon-hee;Shim Jae-Chul;Baek Jung-Hyun;Lee Byung-Won;Kang Ki-Suk
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.1005-1009
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    • 2005
  • The On Board Computer System (ORCS) used for rolling stocks is one of the core equipments in trains, which deals with collecting real-time data of a train to display and record the train's statuses, control the train, and support the driver and maintenance function. Resides, due to high reliability and high speed communication required lately for various electronics including signal1ing devices, train protection system, and multimedia, the necessity of a more robust train communication network is on the lise. This study aims at understanding the technological trend of the current train communication network in order to rapidly cope with the tendency above and providing fundamental data for designing a more advanced communication network for high-speed trains hereafter.

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The Impact of Water Depth and Speed on Lower Muscles Activation During Exercise in Different Aquatic Environments

  • Gyu-sun, Moon
    • International Journal of Internet, Broadcasting and Communication
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    • v.16 no.2
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    • pp.169-178
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    • 2024
  • This study aimed to investigate the effects of water depth and speed on the activation of lower muscles during squat exercises, utilizing electromyography(EMG). It involved ten male participants in there. Participants performed 30 squats over a minute at a speed of 60bpm and maximum speed squats until exhaustion within a minute. The Integrated electromyography(iEMG) readings for the rectus femoris showed statistically significant differences due to water depth and speed, with a significant interaction effect between depth and speed during squat exercises. The iEMG readings for the biceps femoris also showed statistically significant differences, with a significant interaction effect between depth and speed during squat exercises. The iEMG readings for the gastrocnemius showed statistically significant differences according to water depth and speed. However, the interaction effect of water depth and speed during squat exercises did not show a statistically significant difference. In contrast, the iEMG readings for the tibialis anterior demonstrated statistically significant differences, with a statistically significant interaction effect during squats. These findings suggest that water depth and speed positively influence the activation patterns of lower muscles. Therefore, appropriately tailored aquatic exercises based on water depth for individuals with musculoskeletal discomfort, including the elderly or those with physical impairments, can effectively reduce physical strain and enhance balance, as well as physical and perceptual aspects. It is concluded that such exercises could provide a safer and more effective method of exercise compared to ground-based alternatives.

Design and Architecture of Low-Latency High-Speed Turbo Decoders

  • Jung, Ji-Won;Lee, In-Ki;Choi, Duk-Gun;Jeong, Jin-Hee;Kim, Ki-Man;Choi, Eun-A;Oh, Deock-Gil
    • ETRI Journal
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    • v.27 no.5
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    • pp.525-532
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    • 2005
  • In this paper, we propose and present implementation results of a high-speed turbo decoding algorithm. The latency caused by (de)interleaving and iterative decoding in a conventional maximum a posteriori turbo decoder can be dramatically reduced with the proposed design. The source of the latency reduction is from the combination of the radix-4, center to top, parallel decoding, and early-stop algorithms. This reduced latency enables the use of the turbo decoder as a forward error correction scheme in real-time wireless communication services. The proposed scheme results in a slight degradation in bit error rate performance for large block sizes because the effective interleaver size in a radix-4 implementation is reduced to half, relative to the conventional method. To prove the latency reduction, we implemented the proposed scheme on a field-programmable gate array and compared its decoding speed with that of a conventional decoder. The results show an improvement of at least five fold for a single iteration of turbo decoding.

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Sensorless Vertor Control of PMSM using Neural Networks (신경회로망을 이용한 PMSM의 센서리스 벡터제어)

  • Lee, Young-Sil;Lee, Jung-Chul;Lee, Hong-Gyun;Kim, Jong-Gwan;Jung, Tack-Gi;Chung, Dong-Hwa
    • Proceedings of the KIEE Conference
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    • 2003.04a
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    • pp.240-243
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    • 2003
  • Sensorless Vector control of the permanent magnet synchronous motor(PMSM) typically requires knowledge of the PMSM structure and parameters, which in some situations are not readily available or may be difficult to obtain. In this paper, by measuring the currents of the PMSM drive, a neural-network-based rotor position and speed estimation method for PMSM is described. Because the proposed estimator treats the estimated motor speed as the weights, it is possible to estimate motor speed to adapt back propagation algorithm with 2 layered neural network. The proposed control algorithm is applied to PMSM drive system. The operating characteristics controlled by neural networks control are examined in detail.

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Development of Self-Tuning and Adaptive Fuzzy Controller to Control Induction Motor Drive (유도전동기 드라이브의 제어를 위한 자기동조 및 적응 퍼지제어기 개발)

  • Ko, Jae-Sub;Choi, Jung-Sik;Jung, Chul-Ho;Kim, Do-Yeon;Jung, Byung-Jin;Chung, Dong-Hwa
    • Proceedings of the KIEE Conference
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    • 2009.04b
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    • pp.32-34
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    • 2009
  • The field oriented control of induction motors is widely used in high performance applications. However, detuning caused by parameter disturbance still limits the performance of these drives. In order to accomplish variable speed operation, conventional PI-like controllers are commonly used. These controllers provide limited good Performance over a wide range of operation, even under ideal field oriented conditions. This paper is proposed model reference adaptive fuzzy control(MFC) and artificial neural network(ANN) based on the vector controlled induction motor drive system. Also, this paper is proposed control of speed and current using fuzzy adaption mechanism(FAM), MFC and estimation of speed using ANN. The proposed control algorithm is applied to induction motor drive system using FAM, MFC and ANN controller. Also, this paper is proposed the analysis results to verify the effectiveness of this controller.

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A Study on the Flow Control Based Estimated Receiving Capacity on the Video Conference System (화상회의 시스템에서 수신능력 예측을 이용한 흐름제어에 관한 연구)

  • 김상진;남지승
    • Journal of Korea Multimedia Society
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    • v.6 no.3
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    • pp.488-495
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    • 2003
  • With the development of networks, multimedia communication has expanded its application field. From the remote control for household electric appliances to medicine, games, video conferencing and multimedia chatting, multimedia communication is being used in all parts of our lives. This multimedia communication requires the transmission of a lot of data at high speed. But if the transmission rate of the communication network exceeds the processing speed of being used in the high speed network environment, a bottleneck occurs in each node and deteriorates the performance of the network. This is the main reason for the slow speed of data transmission and packet loss. In this paper, considering the client's processing performance, reception performance was predicted and the way of flow control was shown. The computing performance of relevant Processor and its performance was estimated through the actual implementation.

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On the study of depulication method of communication and Backup device for an Electric Car using Flash Disk and Ethernet (Flash DISK와 Ethernet을 이용한 전동차의 통신 이중화 및 백업장치에 관한 연구)

  • Seo, Won-Yong;Yeon, Jun-Sang;Yang, Oh
    • Proceedings of the KIEE Conference
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    • 2002.11c
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    • pp.472-475
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    • 2002
  • This paper presents a high speed ethernet communication and depulication method of communication to prevent decrease of reliability that was generated by high speed communication. Thus communication reliability was improved and this paper was considered that if any physical breakdown of line of communication occurred, other line of communication could operate collect. This paper used Flash memory for setting storage of backup data at Electric Car that have an humidity and a temperature and an impact. also improved reliability and besides matching data format to windows data format realized to confirm application program at PC or note book computer.

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An Accurate Velocity Estimation using Low Resolution Tachometer of High-Speed Trains (고속열차의 저해상도 타코미터를 이용한 정확한 속도 추정에 관한 연구)

  • Lee, Jae-Ho;Kim, Seong Jin;Park, Sungsoo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.1
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    • pp.131-136
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    • 2018
  • Reliable velocity estimation technology for trains is one of technologies used to operate trains safely and effectively. Various sensors such as tachometers, doppler radars, and global positioning systems are used to estimate velocity of a train. Tachometer is widely used to estimate velocity of a trains due to its simplicity, small volume, cost-effectiveness, continuously measurement at high speed, and robustness against noise. Accuracy in the velocity calculation using a tachometer depends on quantization error, measurement error of wheel radius or diameter, and tachometer's imperfection from manufacturing or installation process. In this paper, we present an accurate velocity estimation method using a low-resolution tachometer, which is commonly installed on a high-speed train. Baseline estimation method is proposed to accurately calculate the velocity of the high-speed train from tachometer's pulses. HEMU-430x test train is used for the experiment and verification of the proposed method. Experimental results with several routes show that the proposed method is more accurate than a conventional method.

A Study on ADSL transmission speed enhancement in High-speed Internet (초고속 인터넷을 위한 ADSL 전송속도 향상연구)

  • 김홍모;고남영
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.5
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    • pp.1077-1083
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    • 2000
  • With rising demand of Internet Service, the existing communication for users (aced the restricted capability and speed, and also failed to satisfy consumer's desire for providing service-quality to them. It can be accomplished the broad-band on subscribe-line to offer various multimedia service to subscriber. But it takes a lot of times and costs. Consequently, it stands out the most economic subscribe-line for acheving a broadband scheme that new transmission technology can be realized the high-speed data communication as the present telephone-line and telephone by the general public of FTTH(Fiber To The Home). As using the pseudo line, this paper have the result that the mesured speed was improved by connecting a variable resistor on the line.

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A Study on the High Speed Communication Interface with Virtual Modem (가상 모뎀과의 고속 인터페이스구조에 관한 연구)

  • Song, Tae-Hoon;Song, Moon-Vin;Chung, Yun-Mo
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.1
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    • pp.84-89
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    • 2007
  • In order to design and test an SoC modem for high speed communication, the platform with the architecture of such high speed communication is needed. That platform is needed for testing large data in speed of 500Mbps. This paper shows that transmission data can be uploaded and downloaded by 250Mbps between a virtual modem target board and a PC through the AHB-PCI IP and the speed of based on DPRAM and PCI.