• Title/Summary/Keyword: Real-time Response

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Dynamic effect of high-speed trains on simple bridge structures

  • Adam, Christoph;Salcher, Patrick
    • Structural Engineering and Mechanics
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    • v.51 no.4
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    • pp.581-599
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    • 2014
  • In this paper the overall dynamic response of simple railway bridges subjected to high-speed trains is investigated numerically based on the mechanical models of simply supported single-span and continuous two-span Bernoulli-Euler beams. Each axle of the train, which is composed of rail cars and passenger cars, is considered as moving concentrated load. Distance, magnitude, and maximum speed of the moving loads are adjusted to real high-speed trains and to load models according to Eurocode 1. Non-dimensional characteristic parameters of the train-bridge interaction system are identified. These parameters permit a spectral representation of the dynamic peak response. Response spectra assist the practicing engineers in evaluating the expected dynamic peak response in the design process of railway bridges without performing time-consuming time history analyses.

Design of a Real-time Sensor Node Platform for Efficient Management of Periodic and Aperiodic Tasks (주기 및 비주기 태스크의 효율적인 관리를 위한 실시간 센서 노드 플랫폼의 설계)

  • Kim, Byoung-Hoon;Jung, Kyung-Hoon;Tak, Sung-Woo
    • The KIPS Transactions:PartC
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    • v.14C no.4
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    • pp.371-382
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    • 2007
  • In this paper, we propose a real-time sensor node platform that efficiently manages periodic and aperiodic tasks. Since existing sensor node platforms available in literature focus on minimizing the usage of memory and power consumptions, they are not capable of supporting the management of tasks that need their real-time execution and fast average response time. We first analyze how to structure periodic or aperiodic task decomposition in the TinyOS-based sensor node platform as regard to guaranteeing the deadlines of ail the periodic tasks and aiming to providing aperiodic tasks with average good response time. Then we present the application and efficiency of the proposed real-time sensor node platform in the sensor node equipped with a low-power 8-bit microcontroller, an IEEE802.15.4 compliant 2.4GHz RF transceiver, and several sensors. Extensive experiments show that our sensor node platform yields efficient performance in terms of three significant, objective goals: deadline miss ratio of periodic tasks, average response time of aperiodic tasks, and processor utilization of periodic and aperiodic tasks.

Schedulability Analysis for Task Migration under Multiple Mixed-Criticality Systems (멀티 혼합 중요도 시스템에서 태스크 마이그레이션의 스케줄가능성 분석)

  • Baik, Jeanseong;Kang, Kyungtae
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2019.07a
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    • pp.7-8
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    • 2019
  • In this paper, we applied the migration technique to real-time tasks that have relatively low criticality but still important to be dropped by the mixed-criticality scheduling algorithms. The proposed drop and migrate algorithm analyzes the schedulability by calculating CPU utilization and response time of using task migration. We provide analysis to guarantee the deadline of LO-tasks, by transforming the response time equation specified with migration time. The transformed response time equation was able to analyze the migration schedulability. This algorithm can be used with various mixed-criticality schedulers as a supplementary method. We expect this algorithm will be used for scheduling LO-tasks such as communication task that requires safety guarantee especially in platooning and autonomous driving by utilizing the advantages of multiple node connectivities.

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The study of frictional damper with various control algorithms

  • Mirtaheri, Masoud;Samani, Hamid Rahmani;Zandi, Amir Peyman
    • Earthquakes and Structures
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    • v.12 no.5
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    • pp.479-487
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    • 2017
  • Frictional dampers are used in structural engineering as means of passive control. Meanwhile, frictional damper shave a disadvantage compared to viscous rivals since the slippage force must be exceeded to activate the device, and cannot be ideal full range of possible events. The concept of semi-active control is utilized to overcome this shortcoming. In this paper, a new semi-active frictional damper called Smart Adjustable Frictional (SAF) damper is introduced. SAF damper consists of hydraulic, electronic units and sensors which are all linked with an active control discipline. SAF acts as a smart damper which can adapt its slippage threshold during a dynamic excitation by measuring and controlling the structural response. The novelty of this damper is, while it controls the response of the structure in real time with acceptable time delay. The paper also reports on the results of a series of experiments which have been performed on SAF dampers to obtain their prescribed hysteretic behavior for various control algorithms. The results show that SAF can produce the desired slippage load of various algorithms in real time. Numerical models incorporating control simulations are also made to obtain the hysteretic response of the system which agrees closely with test results.

Prediction of Dynamic Response of Structures Using CMAC (CMAC을 이용한 구조물의 동적응답 예측)

  • Kim, Dong Hyawn;Kim, Hyon Taek;Lee, In Won
    • Journal of Korean Society of Steel Construction
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    • v.12 no.5 s.48
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    • pp.605-615
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    • 2000
  • Cerebellar model articulation controller (CMAC) is introduced and used for the identification of structural dynamic model. CMAC has fascinating features in learning speed. It can learn structural response within a few seconds. Therefore it is suitable for the real time identification structures. Real time identification is required in the control of structure which may be damaged or undergo severe change in mechanical properties due to shrinkage or relaxation etc. In numerical examples, it is shown that CMAC trained with the dynamic response of three-story building can predict responses under not trained earthquakes with allowable error. Finally, CMAC has great potential in structural and control engineering.

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Design and Implementation of Fault-Tolerant IVR for Multi-Channel Service (다중 채널 서비스를 위한 결함허용 IVR 설계 및 구현)

  • Han, Yun-Ki;Koo, Yong-Wan
    • Journal of Internet Computing and Services
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    • v.9 no.3
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    • pp.103-117
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    • 2008
  • General customer uses internet, SMS(Short Message Service), ATM(Automated Teller Machine), DM(Direct Mail), and telephony services, etc, for service of big businesses and small and medium enterprises, securities, financial institutions, bank. In particular, the case of Fire insurance & Securities, financial institutions, banks must meet Real-Time constrain control through QoS(Quality of Service) ensure. In this paper, we design and implement a system model about Fault-Tolerance IVR(Interactive Voice Response) of Multi Channel Service based on CRM(Customer Relationship Management) environment for the first inbound position of customer. The proposed model can be widely used in Large-scale Customer Response service.

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A Real-time Eye Tracking Algorithm for Autostereoscopic 3-Dimensional Monitor (무안경식 3차원 모니터용 실시간 눈 추적 알고리즘)

  • Lim, Young-Shin;Kim, Joon-Seek;Joo, Hyo-Nam
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.8
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    • pp.839-844
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    • 2009
  • In this paper, a real-time eye tracking method using fast face detection is proposed. Most of the current eye tracking systems have operational limitations due to sensors, complicated backgrounds, and uneven lighting condition. It also suffers from slow response time which is not proper for a real-time application. The tracking performance is low under complicated background and uneven lighting condition. The proposed algorithm detects face region from acquired image using elliptic Hough transform followed by eye detection within the detected face region using Haar-like features. In order to reduce the computation time in tracking eyes, the algorithm predicts next frame search region from the information obtained in the current frame. Experiments through simulation show good performance of the proposed method under various environments.

Appliance identification algorithm using multiple classifier system (다중 분류 시스템을 이용한 가전기기 식별 알고리즘)

  • Park, Yong-Soon;Chung, Tae-Yun;Park, Sung-Wook
    • IEMEK Journal of Embedded Systems and Applications
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    • v.10 no.4
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    • pp.213-219
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    • 2015
  • Real-time energy monitoring systems is a demand-response system which is reported to be effective in saving energy up to 12%. Real-time energy monitoring system is commonly composed of smart-plugs which sense how much electrical power is consumed and IHD(In-Home Display device) which displays power consumption patterns. Even though the monitoring system is effective, users should themselves match which smart plus is connected to which appliance. In order to make the matching work to be automatic, the monitoring system need to have appliance identification algorithm, and some works have made under the name of NILM(Non-Intrusive Load Monitoring). This paper proposed an algorithm which utilizes multiple classifiers to improve accuracy of appliance identification. The algorithm proposes to understand each classifiers performance, that is, when a classifier make a result how much the result is reliable, and utilize it in choosing the final result among result candidates from many classifiers. By using the proposed algorithm this paper make 4.5% of improved accuracy with respect to using single best classifier, and 2.9% of improved accuracy with respect to other method using multiple classifiers, so called CDM(Commitee Decision Mechanism) method.

Damage detection of railway bridges using operational vibration data: theory and experimental verifications

  • Azim, Md Riasat;Zhang, Haiyang;Gul, Mustafa
    • Structural Monitoring and Maintenance
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    • v.7 no.2
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    • pp.149-166
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    • 2020
  • This paper presents the results of an experimental investigation on a vibration-based damage identification framework for a steel girder type and a truss bridge based on acceleration responses to operational loading. The method relies on sensor clustering-based time-series analysis of the operational acceleration response of the bridge to the passage of a moving vehicle. The results are presented in terms of Damage Features from each sensor, which are obtained by comparing the actual acceleration response from the sensors to the predicted response from the time-series model. The damage in the bridge is detected by observing the change in damage features of the bridge as structural changes occur in the bridge. The relative severity of the damage can also be quantitatively assessed by observing the magnitude of the changes in the damage features. The experimental results show the potential usefulness of the proposed method for future applications on condition assessment of real-life bridge infrastructures.

Real-time video Surveillance System Design Proposal Using Abnormal Behavior Recognition Technology

  • Lee, Jiyoo;Shin, Seung-Jung
    • International journal of advanced smart convergence
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    • v.9 no.4
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    • pp.120-123
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    • 2020
  • The surveillance system to prevent crime and accidents in advance has become a necessity, not an option in real life. Not only public institutions but also individuals are installing surveillance cameras to protect their property and privacy. However, since the installed surveillance camera cannot be monitored for 24 hours, the focus is on the technology that tracks the video after an accident occurs rather than prevention. In this paper, we propose a system model that monitors abnormal behaviors that may cause crimes through real-time video, and when a specific behavior occurs, the surveillance system automatically detects it and responds immediately through an alarm. We are a model that analyzes real-time images from surveillance cameras and uses I3D models from analysis servers to analyze abnormal behavior and deliver notifications to web servers and then to clients. If the system is implemented with the proposed model, immediate response can be expected when a crime occurs.