• Title/Summary/Keyword: Data transfer time

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A Study on the Flow Control Mechanism based on RTP/RTCP for Real-Time Traffic Transmission (실시간 트래픽 전송을 위한 RTP/RTCP의 흐름제어 기법 연구)

  • Choi, Hyun-Ah;Song, Buk-Sub;Kim, Jeong-Ho
    • Proceedings of the Korea Contents Association Conference
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    • 2007.11a
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    • pp.60-64
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    • 2007
  • Increasing using multimedia services as VoIP, Video conference, DMB, IPTV, etc, it is necessary to increase network traffics and develop the mechanism about a flow control for real time traffic transmission. In order to transfer realtime multimedia data, the transfer rate can be control on network state data measuring packet losses of a receiver and delay time of packets through getting periodical feedback RTP/RTCP packet. This paper describes using efficiant flow control on multicast that can reduce errors according to getting feedback tranfer delay and proposes the mechanism that can adapt dynamic change of network. In simulation, the transfer rate can efficiently be control on dynamic change of network and it makes the maximum of the use of a bandwidth and the minimum of packet losses.

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Predicting Dynamic Response of a Railway Bridge Using Transfer-Learning Technique (전이학습 기법을 이용한 철도교량의 동적응답 예측)

  • Minsu Kim;Sanghyun Choi
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.36 no.1
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    • pp.39-48
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    • 2023
  • Because a railway bridge is designed over a long period of time and covers a large site, it involves various environmental factors and uncertainties. For this reason, design changes often occur, even if the design was thoroughly reviewed in the initial design stage. In particular, design changes of large-scale facilities, such as railway bridges, consume significant time and cost, and it is extremely inefficient to repeat all the procedures each time. In this study, a technique that can improve the efficiency of learning after design change was developed by utilizing the learning result before design change through transfer learning among deep-learning algorithms. For analysis, scenarios were created, and a database was built using a previously developed railway bridge deep-learning-based prediction system. The proposed method results in similar accuracy when learning only 1000 data points in the new domain compared with the 8000 data points used for learning in the old domain before the design change. Moreover, it was confirmed that it has a faster convergence speed.

The Effect of the Learning Transfer Climate of Korea Coast Guard on the Learning and Learning Transfer (해양경찰공무원의 학습전이풍토가 교육훈련의 전이효과에 미치는 영향)

  • Lee, Seung-Hyun;Yoon, Sung-Hyun
    • Korean Security Journal
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    • no.51
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    • pp.61-78
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    • 2017
  • This study aims to empirically validate the relationship between organizational learning transfer climate and the transfer of training and to enhance the transfer of training among South Korean coast guards. The empirical data was collected through 526 South Korean coast guards admitted to the institute, and support by managers and peers, and potential for organizational change were selected as independent variables for multiple regression. As a result, the transfer of training is positively correlated with support of mangers and peers, and potential for organizational change, thus suggesting factors like supervisor participation and long-term educational planning as policy implications for the effective transfer of training to work environment. Though findings from research cannot be generalized to the broader population due to limitations of sampling, this study does find its significance in that organizational learning transfer climate was considered as a key factor influencing the transfer of learning for the first time.

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Data-Based Model Approach to Predict Internal Air Temperature of Greenhouse (데이터 기반 모델에 의한 온실 내 기온 변화 예측)

  • Hong, Se Woon;Moon, Ae Kyung;Li, Song;Lee, In Bok
    • Journal of The Korean Society of Agricultural Engineers
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    • v.57 no.3
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    • pp.9-19
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    • 2015
  • Internal air temperature of greenhouse is an important variable that can be influenced by the complex interaction between outside weather and greenhouse inside climate. This paper focuses on a data-based model approach to predict internal air temperature of the greenhouse. External air temperature, solar radiation, wind speed and wind direction were measured next to an experimental greenhouse supported by the Electronics and Telecommunications Research Institute and used as input variables for the model. Internal air temperature was measured at the center of three sections of the greenhouse and used as an output variable. The proposed model consisted of a transfer function including the four input variables and tested the prediction accuracy according to the sampling interval of the input variables, the orders of model polynomials and the time delay variable. As a result, a second-order model was suitable to predict the internal air temperature having the predictable time of 20-30 minutes and average errors of less than ${\pm}1K$. Afterwards mechanistic interpretation was conducted based on the energy balance equation, and it was found that the resulting model was considered physically acceptable and satisfied the physical reality of the heat transfer phenomena in a greenhouse. The proposed data-based model approach is applicable to any input variables and is expected to be useful for predicting complex greenhouse microclimate involving environmental control systems.

The Prediction of Temperature in Composite Box Girder Bridges (합성 박스형 교량의 온도 예측)

  • Chang, Sung Pil;Im, Chang Kyun
    • Journal of Korean Society of Steel Construction
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    • v.9 no.3 s.32
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    • pp.431-440
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    • 1997
  • The paper describes a theoretical model for the prediction of bridge temperatures from meteorological data measured at bridge site and local meteorological center together with existing finite element heat transfer theory and solar radiation transfer theory to determine the time dependent temperature distribution of bridge. In this analytical model, the most adequate equation for the calculation of solar radiation on the bridge surface, which is dominant in day time is described based on the results of several experimental studies for the solar energy. The validity of this model is tested against field data obtained from long term experimental program on Sadang Viaduct in Seoul. Also, this paper describes the linear correlation between design variables and meteorological data to establish analytical criteria for the prediction of the average temperature, which are responsible for the longitudinal deformation of the bridges and of the vertical differential temperature profiles. which are responsible for the bending deformations from the long term experimental results.

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User Benefit Analysis By Transfer Fare Policy : Focuses on the case of Gyeonggi-do (지역별 대중교통 환승혜택 형평성 개선방안에 관한 연구 : 경기도를 중심으로)

  • Eunyoung Kim;Donghyung Yook;Seungneo Son
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.21 no.6
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    • pp.225-240
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    • 2022
  • Gyeonggi-do comprises several types of areas, including urban, semi-urban, and rural areas. The availability of public transportation services varies depending on the area types, but the fare structure is based on a simple transfer rule, i.e., a transfer is free when completed within 30 minutes. As a result, users in non-urban areas with a poor frequency of public transportation services do not receive transfer discounts because most of the bus routes in these areas have a gap of more than 30 minutes between services. In terms of equality of opportunity, the transfer rule is being applied unfavorably and, as a result, equality of opportunity of the non-urban commuter is severely affected. Therefore, this study analyzed the user benefits mainly stemming from transfer fares using the smart card data of commuters using public transportation in Gyeonggi-do. An index called the beneficiary rate of the free transfer was developed and a scenario analysis was conducted based on the various levels of the rate. The results of this analysis proved that the users of public transportation services in non-urban areas in Gyeonggi-do can only receive transfer benefits by the extended time for free transfer and not by the implementation of a uniform policy irrespective of the type of area. The study also suggested an equitable fare transfer system and policy alternatives.

Design Scheme of A Micro Real-Time Control System with CAN and RTOS (CAN과 RTOS를 내장한 소형 실시간 시스템 설계 기법)

  • Lim, Young-Gyu;Kim, Dong-Seoung
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.5
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    • pp.207-215
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    • 2014
  • In this paper, we propose a Micro Real-Time Control System (MRTCS) for decreasing the delay during interrupts processing and data transfer on sensor nodes. The MRTCS consists of a control, sensor nodes based on Controller Area Network (CAN) device. The control node was designed with Real Time Operating System (RTOS) on top of the small Micro Control Unit (sMCU). Sensor nodes have the CAN device without sMCU, which have multiple Digital Inputs, Outputs (DI/DO) and the CAN controller. We have evaluated with OCTAVE v3.6.4 from open source for system performance. Simulation results show that the system performance was increased through the delay reducing for interrupt processing and internal data transfer. We verify that a proposed MRTCS approach will be adapted to various real-time control system.

TFRC Flow Control Mechanism based on RTP/RTCP for Real-time Traffic Transmission (실시간 트래픽 전송을 위한 RTP/RTCP의 TFRC 흐름제어 기법)

  • Choi, Hyun-Ah;Song, Bok-Sob;Kim, Jeong-Ho
    • The Journal of the Korea Contents Association
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    • v.8 no.8
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    • pp.57-64
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    • 2008
  • In this paper, to resolve the problem caused by a network state information inaccuracy the slow delay time that conclusion of network state of one way delay time which accuracy delay time information, according to network state changes on the based TFRC flow control, and suggest that flow control mechanism to adjust transfer rate fit of real time multimedia data. In simulation, to measure of netowork state information that on the average about 12% difference of compared RTT and $OWD{\times}2$. When used RTT, used fair bandwidth TFRC much better than TCP about 32%, when used OWD, difference about 3% used fair bandwidth. Thus, conclusion of accuracy network state that used fair bandwidth according to network state changes on the based TFRC, users can support service of high quality that flow control mechanism to adjust transfer rate fit of real time data.

Design of a hardware system for ECG feature extraction (ECG 특징추출을 위한 하드웨어시스템의 설계)

  • 이경중;윤형로;이명호
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.697-700
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    • 1988
  • This paper describes the design of a hardware system for ECG feature extraction based on pipeline processor consisting of three computers. ECG data is acquisited by 12 bit A/D converter with hardware QRS triggred detector. Four diagnostic parameters-heart, axis, and ST axis, and ST segment are used for the classification and the diagnosis of arrhythmia. The functions of the main CPU were distributed and processed with three microcomputers. Therefore the effective data process and the real time process using microcomputer can be obtained. The interconnection structure consisting of two common memory units is designed to decrease the delay time caused by data transfer between processors and designed by which the delay time can be taken 1% of one clock period.

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Design of Pipeline Processor for ECG Feature Extraction (ECG 특징추출을 위한 파이프라인 프로세서의 설계)

  • 이경중;윤형로
    • Journal of Biomedical Engineering Research
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    • v.9 no.1
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    • pp.79-86
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    • 1988
  • This paper describes the design of a hardware systenl for ECG feature extraction based on pipeline processor consistinsf of three microcomputers. ECG data is acquisited by 12 bit A/D converter with hardware QRS triggered detector. Four diagnostic parameters parameters-heart rate, morPhology, axis, and 57 segment-are used for the classification and the diagnosis of arrhythmia. The functions of the main CPU were distributed and processed with three microcomputers. Therefore the effective data process and the real time process using microcomputer can be obtained. The interconnection structure consisting of two common memory units is designed to decrease the delay time caused by data transfer between processors and designed by which the delay time can be taken Loye of one clock period.

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