• Title/Summary/Keyword: physical simulator

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IDENTIFICATION OF AIRWAY CHARACTERISTICS USING THE INPUT IMPEDANCE

  • Tung, V.X.;Jumaily, Al;Cheng, S.H.;Ro, S.H.
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1037-1044
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    • 2007
  • In an attempt to determine the correlations between the input acoustic impedance and the variations of the physical characteristics of the terminal elements, a five-lobe branched tube-network is mathematically developed and experimentally simulated using a lung simulator. The model takes into account some realistic conditions such as varying cross-sectional areas, flexible wall properties and branching. The effects of airway constrictions expressed by lobe stiffness variations on the impedance are determined for a range of frequencies up to 256 Hz. It is concluded that the developed model is capable of non-invasively predicting various physiological changes in the airway passages.

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Real-Time Communication of Periodic Messages on Wireless Sensor and Actor Networks (무선 센서-엑터 네트워크에서 주기적 메시지의 실시간 전송)

  • Ngo, Dao Quan;Lee, Sang-Jin;Kim, Myung-Kyun
    • Proceedings of the Korean Information Science Society Conference
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    • 2008.06d
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    • pp.291-296
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    • 2008
  • Wireless network technologies are becoming more widely used in industrial environment. The industrial communication system requires a real-time delivery of messages. The sensors periodically senses the physical environment and wants to deliver the data in real-time to the sink. This paper proposes a real-time protocol for periodic messages on wireless sensor and actor networks to be used in industrial communications. The proposed protocol delivers the data message using the shortest path from the source and the nearest actor. The protocol considers the energy consumption by reducing the number of broadcast messages during flooding. We have evaluated the performance of the proposed protocol using QualNet simulator. The simulation results show that the data messages have been delivered in real-time and the number of broadcast messages is reduced from 90% to 35% compared the existing protocols.

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Simulation Performance of WAVE System with Combined DD-CE and LMMSE Smoothing Scheme in Small-Scale Fading Models

  • Seo, Jeong-Wook;Kwak, Jae-Min;Kim, Dong-Ku
    • Journal of information and communication convergence engineering
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    • v.8 no.3
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    • pp.281-288
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    • 2010
  • This paper investigates the performance of IEEE 802.11p wireless access in vehicular environments (WAVE) system in small-scale fading models reported by Georgia Institute of Technology (Georgia Tech). We redesign the small-scale fading models to be applied to the computer simulation and develop the IEEE 802.11p WAVE physical layer simulator to provide the bit error rate and packet error rate performances. Moreover, a new channel estimator using decision directed channel estimation and linear minimum mean square error smoothing is proposed in order to improve the performance of the conventional least square channel estimator using two identical long training symbols. The simulation results are satisfactorily coincident with the scenarios of Georgia Tech report, and the proposed channel estimator significantly outperforms the conventional channel estimator.

Implementation of a Fieldbus System Based On Distributed Network Protocol Version 3.0 (Distributed Network Protocol Version 3.0을 이용한 필드버스 시스템 구현)

  • 김정섭;김종배;최병욱;임계영;문전일
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.4
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    • pp.371-376
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    • 2004
  • Distributed Network Protocol Version 3.0 (DNP3.0) is the communication protocol developed for the interoperability between a RTU and a central control station of SCADA in the power utility industry. In this paper DNP3.0 is implemented by using HDL with FPGA and C program on Hitachi H8/532 processor. DNP3.0 is implemented from physical layer to network layer in hardware level to reduce the computing load on a CPU. Finally, the ASIC for DNP3.0 has been manufactured from Hynix Semiconductor. The commercial feasibility of the hardware through the communication test with ASE2000 and DNP Master Simulator is performed. The developed protocol becomes one of IP, and can be used to implement SoC for the terminal device in SCADA systems. Also, the result can be applicable to various industrial controllers because it is implemented in HDL.

Drone Simulation Technologies (드론 시뮬레이션 기술)

  • Lee, S.J.;Yang, J.G.;Lee, B.S.
    • Electronics and Telecommunications Trends
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    • v.35 no.4
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    • pp.81-90
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    • 2020
  • The use of machine learning technologies such as deep and reinforcement learning has proliferated in various domains with the advancement of deep neural network studies. To make the learning successful, both big data acquisition and fast processing are required. However, for some physical world applications such as autonomous drone flight, it is difficult to achieve efficient learning because learning with a premature A.I. is dangerous, cost-ineffective, and time-consuming. To solve these problems, simulation-based approaches can be considered. In this study, we analyze recent trends in drone simulation technologies and compare their features. Subsequently, we introduce Octopus, which is a highly precise and scalable drone simulator being developed by ETRI.

The Effect of Changing Driving Brightness on Older Drivers

  • Jeon, Yong-Wook;Shin, Sung-Heon
    • Journal of the Ergonomics Society of Korea
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    • v.29 no.4
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    • pp.619-624
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    • 2010
  • The traffic accidents of the aged are increasing because old people generally experience a decline of physical functions and judgment but their dependence on automobiles increases. In order to investigate the older drivers' response to traffic signs and surrounding environment according to changing driving brightness, this study measured the visual cognitive behavior, driving behavior, and subjective evaluation while the driving brightness was changed using a driving simulator. Furthermore, the drivers who recognized traffic signs and those who did not were compared. As a result, it was found that some older drivers had declined ability of cognition, some failed to adapt to rapid brightness change even if sufficient attention was given to traffic sign, and some could not safely control the vehicle when approaching intersections. Therefore, the development of support systems for aged drivers in traffic environment is necessary in the future.

ADVANCES IN MULTI-PHYSICS AND HIGH PERFORMANCE COMPUTING IN SUPPORT OF NUCLEAR REACTOR POWER SYSTEMS MODELING AND SIMULATION

  • Turinsky, Paul J.
    • Nuclear Engineering and Technology
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    • v.44 no.2
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    • pp.103-122
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    • 2012
  • Significant advances in computational performance have occurred over the past two decades, achieved not only by the introduction of more powerful processors but the incorporation of parallelism in computer hardware at all levels. Simultaneous with these hardware and associated system software advances have been advances in modeling physical phenomena and the numerical algorithms to allow their usage in simulation. This paper presents a review of the advances in computer performance, discusses the modeling and simulation capabilities required to address the multi-physics and multi-scale phenomena applicable to a nuclear reactor core simulator, and present examples of relevant physics simulation codes' performances on high performance computers.

Neighbor-Referenced Coordination of Multi-robot Formations (다중 로봇의 네이버기준 편대제어)

  • Lee, Geun-Ho;Chong, Nak-Young
    • The Journal of Korea Robotics Society
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    • v.3 no.2
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    • pp.106-111
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    • 2008
  • This paper presents a decentralized coordination for a small-scale mobile robot teams performing a task through cooperation. Robot teams are required to generate and maintain various geometric patterns adapting to an environment and/or a task in many cooperative applications. In particular, all robots must continue to strive toward achieving the team's mission even if some members fail to perform their role. Toward this end, given the number of robots in a team, an effective coordination is investigated for decentralized formation control strategies. Specifically, all members are required first to reach agreement on their coordinate system and have an identifier (ID) for role assignment in a self-organizing way. Then, employing IDs on individual robots within a common coordinate system, a decentralized neighbor-referenced formation control is realized to generate, keep, and switch between different geometric shapes. This approach is verified using an in-house simulator and physical mobile robots. We detail and evaluate the formation control approach, whose common features include self-organization, robustness, and flexibility.

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Dynamics modeling of a GHP in cooling mode for development of control algorithm (제어 알고리즘 개발을 위한 GHP 냉방모드 동특성 모델링)

  • Shin Younggy;Kim Young Il
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.3
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    • pp.243-249
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    • 2005
  • The present study has been conducted to simulate dynamics of a gas engine-driven heat pump(GHP) for design of control algorithm. The dynamic modeling of a GHP was based on conservation laws of mass and energy. For automatic control of refrigerant pressures, actuators such as engine speed, outdoor fan, coolant three-way valves and liquid injection valve were PI or P controlled. The simulation results showed physical behavior that is realistic enough to apply for control algorithm design.

Development of Virtual Integrated Prototyping Simulation Environment for Plasma Chamber Analysis and Design (VIP-SEPCAD) (플라즈마 챔버의 특성 분석 및 최적 설계를 위한 가상의 시뮬레이션 환경 개발)

  • 김헌창;설용태
    • Journal of the Semiconductor & Display Technology
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    • v.2 no.4
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    • pp.9-12
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    • 2003
  • This paper describes a newly developed simulation environment for analysis and design of a plasma processing chamber based on first principles including complicated physical and chemical interactions of plasma, fluid dynamics of neutrals, and transport phenomena of particles. Capabilities of our simulator, named VIP-SEPCAD (Virtual Integrated Prototyping Simulation Environment for Plasma Chamber Analysis and Design), are demonstrated through a two dimensional simulation of an oxygen plasma chamber. VIP-SEPCAD can provide plasma properties such as spatiotemporal profiles of plasma density and potential, electron temperature, ion flux and energy, etc. By coupling neutral and particle transport models with a three moment plasma model, VIP-SEPCAD can also predict spatiotemporal profiles of chemically reactive species and particles exist in plasma.

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