• Title/Summary/Keyword: P-wave speed

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Implementation of WAVE system for ITS (지능형 도로 교통망을 위한 WAVE 시스템 구현)

  • Lee, Se-Yeun;Jeong, Han-Gyun;Shin, Dae-Kyo;Lim, Ki-Taeg;Lee, Joo-Shin
    • Journal of Advanced Navigation Technology
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    • v.13 no.6
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    • pp.933-942
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    • 2009
  • In this paper, the WAVE technology for IT based on Intelligent Transport System(ITS) which using by IEEE 802.11a PHY, IEEE 802.11p MAC(Medium Access Control) and IEEE P1609.3 was implemented. The WAVE system was designed that has maximum 0.5km communication range for RSU(Road Side Equipment) between vehicle, 12Mbps transfer speed when downlink at maximum 120km/h vehicle speed. To verify suitableness of the WAVE system for ITS, we measured several parameters on the real road: communication range when low and high speed, link establishment time, data transfer speed, PER (Percent Error Rate), and latency. From the experiment results, we demonstrated that WAVE is a suitable technology for IT based on ITS.

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A Tentative Methodology for Quality Control of Trackbed Fills Using Field and Laboratory P-Wave Measurements

  • Park, Chul-Soo;Park, In-Beom;Kim, Eun-Jung;Mok, Young-Jin
    • International Journal of Railway
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    • v.1 no.2
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    • pp.64-71
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    • 2008
  • The quality of track-bed fills of railways has been controlled by field measurements of density $({\gamma}_d)$ and the results of plate-load tests. The control measures are compatible with the design procedures whose design parameter is $k_{30}$ for both ordinary-speed railways and high-speed railways. However, one of fatal flaws of the design procedures that there are no simple laboratory measurement procedures for the design parameters ($k_{30}$ or, $E_{v2}$ and $E_{v2}/E_{v1}$) in design stage. A new quality control procedure, in parallel with the advent of the new design procedure, is being proposed. This procedure is based upon P-wave velocity involving consistently the evaluation of design parameters in design stage and the field measurements during construction. The Key concept of the procedure is that the target value for field compaction control is the P-wave velocity determined at OMC using modified compaction test, and direct-arrival method is used for the field measurements during construction. The procedure was verified at a test site and the p-wave velocity turned out to be an excellent control measure. The specifications for the control also include field compaction water content of OMC${\pm}$2% as well as the p-wave velocity.

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A numerical analysis of the delivery pressure wave in a 210-kW/cyl fuel injection pump for medium-speed diesel engines (210 kW/cyl 급 중속디젤엔진의 연료분사펌프 송출 압력파에 관한 수치 해석)

  • Kong, Kyeong-Ju;Jung, Suk-Ho;Lee, Sang-Deuk;Koh, Dae-Kwon
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.4
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    • pp.295-300
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    • 2016
  • This paper presents a numerical analysis of the delivery pressure wave in a 210-kW/cyl fuel injection pump (P. Corporation, Changwon-si, Korea) for medium-speed diesel engines using Ansys Fluent R15.0. Results obtained from experiment and from numerical analysis of the fuel delivery pressure wave were compared and found to be similar, thereby confirming the reliability of the numerical analysis of the delivery pressure wave in the fuel injection pump.

A Study on the Performance of WAVE Communication System using Jakes Channel Model (Jakes 채널 모델을 이용한 WAVE 통신시스템 성능에 관한 연구)

  • Oh, Se-Kab;Choi, Jae-Myeong;Kang, Heau-Jo
    • Journal of Advanced Navigation Technology
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    • v.13 no.6
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    • pp.943-949
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    • 2009
  • In this paper, the 5.9GHz WAVE(Wireless Access in Vehicular Environments) channel modeling is used by the Jakes channel model for the suitability of the fast wireless channel fluctuation. The performance analysed the fading signal constellation and the spectrum in the IEEE 802.11p spectrum mask, the Doppler effect, the modulation scheme. In addition, the vehicular speed, exactly the performance analysis the WAVE communication systems follow the Doppler effect.

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Performance evaluation of WAVE communication systems under a high-speed driving condition in a highway (고속주행 환경에서의 WAVE 통신장치 성능분석)

  • Song, Yoo Seung;Lee, Sang Woo;Oh, Hyun Seo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.3
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    • pp.96-102
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    • 2013
  • In recent years, a variety of ITS services are available such as driving information, road conditions, V2X messages as well as navigation and traffic jams notification. The development of ITS services is accelerating by V2X communication technologies for high-speed vehicles. In this paper, WAVE communication devices based on the IEEE802.11p standard is introduced as a solution of V2X communication technologies. The H/W and S/W structures of the WAVE communication device and the characteristics of RF/antenna are described. The performance is evaluated in the test road by measuring throughput, PER and latency. The implemented WAVE communication device has 6~7 Mbps throughput with 10% PER at 1km coverage. The packet latency is less than 3ms for the whole test road. It is shown that the implemented WAVE technology is satisfactory to provide ITS services and Internet video-streaming services.

RF Circuit Design for IEEE 802.11p Implementation (IEEE 802.11p 구현을 위한 RF 회로 설계)

  • Lee, Se-Yeun;Lee, Myung-Ho
    • Journal of Advanced Navigation Technology
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    • v.16 no.1
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    • pp.54-61
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    • 2012
  • The WAVE specification, which for the Next-Generation ITS environment is a common title: IEEE 802.11p and IEEE P1609 specifications. These days, there are many activities for researching WAVE specification by release of the IEEE 802.11p specification. The difference between high-speed vehicle environment and the indoor environment, the wireless communication channel mode is that much more severe. Thus, the wireless communication system design, temperature, noise, multipath fading and can degrade the performance of the system points should be fully considered matters of. In this paper, we showed WAVE wireless communication system which based on IEEE 802.11p PHY/MAC design process, and also showed solving process many implementation problems.

A Study on the Analysis and Simulation of WAVE Channel for IEEE802.11p Communication Systems (IEEE802.11p 통신 시스템을 위한 WAVE 채널 분석과 시뮬레이션 연구)

  • Kwak, Jae-Min
    • Journal of Advanced Navigation Technology
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    • v.13 no.2
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    • pp.214-223
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    • 2009
  • In this paper, we analysed and simulated the high speed mobile wireless channel for IEEE802.11p WAVE/DSRC standard draft. IEEE802.11p working group measured and suggested 6 channel model for WAVE/DSRC systems which is used for vehicle to vehicle or vehicle to infra communication. However, the models only provides numerical model, it did not provide Computer based software simulation model. So it can not be used directly for performance estimation of WAVE system. In this paper we suggested simulation technique of WAVE channel simulation which is developed S/W based WAVE channnel simulator. The simulation results for PSD, LCR, and AFD are also obtained, which can be used for performance estimation of IEEE802.11p based vehicular communication system.

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Design and Implementation of an IEEE WAVE Multi-channel Transmission Emulator (IEEE WAVE 멀티채널 전송 에뮬레이터의 설계 및 구현)

  • Lee Woo-Sin;Lee Hyuk-Joon;Lee Sang-Lock;Lee Won-Gi
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.4 no.3 s.8
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    • pp.1-8
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    • 2005
  • IEEE WAVE(Wireless Access in Vehicular Environment) is being developed to operate in 5 GHz DSRC band to provide cars moving at high-speed with vehicle-to-vehicle and vehicle-to-roadside communication. IEEE P 1609.3 of the WAVE protocol stack defines how multiple channels are used based on the exchange of provider-service-tables (PST) and user-service-tables (UST) for rapid link establishment and data transmission. This paper presents the design and implementation of an IEEE WAVE multi-channel transmission emulator that we have developed to study the operation of protocol and applications. Applications for a public-safety and a download service have been implemented and are shown to operate effectively on top of the emulator.

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Fractional wave propagation in radially vibrating non-classical cylinder

  • Fadodun, Odunayo O.;Layeni, Olawanle P.;Akinola, Adegbola P.
    • Earthquakes and Structures
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    • v.13 no.5
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    • pp.465-471
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    • 2017
  • This work derives a generalized time fractional differential equation governing wave propagation in a radially vibrating non-classical cylindrical medium. The cylinder is made of a transversely isotropic hyperelastic John's material which obeys frequency-dependent power law attenuation. Employing the definition of the conformable fractional derivative, the solution of the obtained generalized time fractional wave equation is expressed in terms of product of Bessel functions in spatial and temporal variables; and the resulting wave is characterized by the presence of peakons, the appearance of which fade in density as the order of fractional derivative approaches 2. It is obtained that the transversely isotropic structure of the material of the cylinder increases the wave speed and introduces an additional term in the wave equation. Further, it is observed that the law relating the non-zero components of the Cauchy stress tensor in the cylinder under consideration generalizes the hypothesis of plane strain in classical elasticity theory. This study reinforces the view that fractional derivative is suitable for modeling anomalous wave propagation in media.

Performance Evaluation of WAVE Communication System for the Next-Generation ITS (차세대 ITS를 위한 WAVE 통신 시스템 성능 평가)

  • Lee, Se-Yeun;Jeong, Han-Gyun;Shin, Dae-Kyo;Lim, Ki-Taeg;Lee, Myung-Ho
    • Journal of Advanced Navigation Technology
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    • v.15 no.6
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    • pp.1059-1067
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    • 2011
  • Next-Generation ITS environment requires high-speed data packet transmission, security, authentication, and hand-over supportable for driving vehicle on road by installing RSEs and OBUs. Therefore, wireless communication technology for next-generation ITS services are advancing to 200km/h maximum speed supportable, 1km communication radius, minimum 10Mbps hish-speed datarate for multimedia data(such as text, images, movie clips and so on) supportable, high reliability. In this paper, we implemented WAVE communication system which based on IEEE 802.11p PHY/MAC and evaluated that the system meets next-generation ITS environments.