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Hidenori Muramatsu – One of the best experts on this subject based on the ideXlab platform.

  • analysis of termination impedance influence to radiated emission from ac cable with cmad
    International Symposium on Electromagnetic Compatibility, 2014
    Co-Authors: Nobuo Kuwabara, Kunihiro Osabe, Takuto Nakanishi, Hidenori Muramatsu

    Abstract:

    The method of stabilizing termination impedance at AC cables is discussed to improve the reproducibility of test results between test sites. The common-mode Absorbing Device (CMAD) and the VHF band line impedance stabilization network (VHF-LISN) were investigated as the Devices which can stabilize the termination impedance, and the investigation indicated that the deviation between test sites depended on the type of equipment when CMAD was used as the Device. The phenomenon was studied by connecting the artificial network (AN) to the AC cable end. Comb generator and PC were used for the study as EUT. The termination impedance of the AC cable was changed by the AN, and then, the radiated electric field strength and the common-mode current were measured. The investigation indicated that the standard deviation of the field strength is similar to that of the common-mode current. The AC cable with CMAD and the AN were presented by an equivalent circuit, and the circuit parameters were determined from the measurement value of S-parameters. The equivalent circuit and disturbance sources of EUT were determined from the measured currents intensity and S-parameters. The common-mode current was calculated when the termination impedance of the AC cable was changed, and the standard deviation of the common-mode current was estimated. The comparison with the measurement value showed that the type of EUT influenced the deviation between test sites.

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  • improvement of radiated emission measurement reproducibility by vhf lisn interim results of international inter laboratory comparison
    International Symposium on Electromagnetic Compatibility, 2014
    Co-Authors: Shinichi Okuyama, Kunihiro Osabe, Katsuyuki Tanakajima, Hidenori Muramatsu

    Abstract:

    At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to equipment under test (EUT) in the test site. Because of the difference in the terminating condition of EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we developed a Device called very high frequency line impedance stabilization network (VHF-LISN) and investigated its effectiveness. After performing the domestic inter-laboratory comparison, we proposed an international inter-laboratory comparison program to CISPR Subcommittee I, and the proposal was accepted. For the comparison purpose, we have investigated the reproducibility also by using a common mode Absorbing Device (CMAD) and a versatile coupling/decoupling network of AC mains for emission testing (CDNE-M). This investigation is just in progress as a future work of CISPR SC-I WG2 until February, 2014. As a glance from an interim result, we could find that all Devices are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such Device. But also we were able to presume that the effectiveness of Devices to the measurement reproducibility differs with the type of EUT.

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  • investigation on effectiveness of very high frequency line impedance stabilization network vhf lisn for measurement reproducibility
    International Symposium on Electromagnetic Compatibility, 2013
    Co-Authors: Shinichi Okuyama, Kunihiro Osabe, Katsuyuki Tanakajima, Hidenori Muramatsu

    Abstract:

    At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to the equipment under test (EUT) in the test site, i.e., do not define the common mode impedance as the terminating condition on the far end of the EUT power cable. Because of the difference in the terminating condition of the EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we investigated the effectiveness of some Devices through inter-laboratory comparison measurements in which a very high frequency line impedance stabilization network (VHF-LISN) and a common mode Absorbing Device (CMAD), one at a time, were inserted between the mains network and the EUT power cable for the purpose of defining the terminating condition. As a result, we found that both VHF-LISN and CMAD are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such Device, but we also found that their effectiveness differs with the type of EUT.

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Abdul Qadir Bhatti – One of the best experts on this subject based on the ideXlab platform.

  • Computational Modeling of Energy Dissipation Characteristics of Expanded Polystyrene (EPS) Cushion of Reinforce Concrete (RC) Bridge Girder Under Rockfall Impact
    International Journal of Civil Engineering, 2018
    Co-Authors: Abdul Qadir Bhatti

    Abstract:

    As a part of rock sheds, reinforced concrete (RC) girder is usually covered by traditional soil cushion as a shock-Absorbing Device. In this paper, expanded polystyrene (EPS) has been numerically modeled using RC girder under impact load analysis. A numerical method was established in comparison with the proposed prototype experiment. Furthermore, expanded polystyrene (EPS) cushions of different thicknesses and densities as an energy dissipation Device for rockfall impact were tested using the proposed numerical model. The dynamic analysis and modeling were performed using LS-DYNA. The impact forces and displacements of the RC girder were measured. The simulated results revealed a major increase in terms of energy dissipation after introducing the EPS cushion. The results obtained from this study are: (1) the displacement can be reduced by 25% as compared to sand cushion as Absorbing material using an EPS layer, (2) a large decrease in contact force was observed using a layer of EPS cushion at the top of the RC girder having lesser density of 19 kg/m^3, and (3) EPS cushions with 0.5 m thicker layer and lower 19 kg/m^3 density showed more remarkable energy dissipation effect when all the other conditions were the same.

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  • Computational Modeling of Energy Dissipation Characteristics of Expanded Polystyrene (EPS) Cushion of Reinforce Concrete (RC) Bridge Girder Under Rockfall Impact
    International Journal of Civil Engineering, 2018
    Co-Authors: Abdul Qadir Bhatti

    Abstract:

    As a part of rock sheds, reinforced concrete (RC) girder is usually covered by traditional soil cushion as a shock-Absorbing Device. In this paper, expanded polystyrene (EPS) has been numerically modeled using RC girder under impact load analysis. A numerical method was established in comparison with the proposed prototype experiment. Furthermore, expanded polystyrene (EPS) cushions of different thicknesses and densities as an energy dissipation Device for rockfall impact were tested using the proposed numerical model. The dynamic analysis and modeling were performed using LS-DYNA. The impact forces and displacements of the RC girder were measured. The simulated results revealed a major increase in terms of energy dissipation after introducing the EPS cushion. The results obtained from this study are: (1) the displacement can be reduced by 25% as compared to sand cushion as Absorbing material using an EPS layer, (2) a large decrease in contact force was observed using a layer of EPS cushion at the top of the RC girder having lesser density of 19 kg/m^3, and (3) EPS cushions with 0.5 m thicker layer and lower 19 kg/m^3 density showed more remarkable energy dissipation effect when all the other conditions were the same.

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Kunihiro Osabe – One of the best experts on this subject based on the ideXlab platform.

  • analysis of termination impedance influence to radiated emission from ac cable with cmad
    International Symposium on Electromagnetic Compatibility, 2014
    Co-Authors: Nobuo Kuwabara, Kunihiro Osabe, Takuto Nakanishi, Hidenori Muramatsu

    Abstract:

    The method of stabilizing termination impedance at AC cables is discussed to improve the reproducibility of test results between test sites. The common-mode Absorbing Device (CMAD) and the VHF band line impedance stabilization network (VHF-LISN) were investigated as the Devices which can stabilize the termination impedance, and the investigation indicated that the deviation between test sites depended on the type of equipment when CMAD was used as the Device. The phenomenon was studied by connecting the artificial network (AN) to the AC cable end. Comb generator and PC were used for the study as EUT. The termination impedance of the AC cable was changed by the AN, and then, the radiated electric field strength and the common-mode current were measured. The investigation indicated that the standard deviation of the field strength is similar to that of the common-mode current. The AC cable with CMAD and the AN were presented by an equivalent circuit, and the circuit parameters were determined from the measurement value of S-parameters. The equivalent circuit and disturbance sources of EUT were determined from the measured currents intensity and S-parameters. The common-mode current was calculated when the termination impedance of the AC cable was changed, and the standard deviation of the common-mode current was estimated. The comparison with the measurement value showed that the type of EUT influenced the deviation between test sites.

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  • improvement of radiated emission measurement reproducibility by vhf lisn interim results of international inter laboratory comparison
    International Symposium on Electromagnetic Compatibility, 2014
    Co-Authors: Shinichi Okuyama, Kunihiro Osabe, Katsuyuki Tanakajima, Hidenori Muramatsu

    Abstract:

    At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to equipment under test (EUT) in the test site. Because of the difference in the terminating condition of EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we developed a Device called very high frequency line impedance stabilization network (VHF-LISN) and investigated its effectiveness. After performing the domestic inter-laboratory comparison, we proposed an international inter-laboratory comparison program to CISPR Subcommittee I, and the proposal was accepted. For the comparison purpose, we have investigated the reproducibility also by using a common mode Absorbing Device (CMAD) and a versatile coupling/decoupling network of AC mains for emission testing (CDNE-M). This investigation is just in progress as a future work of CISPR SC-I WG2 until February, 2014. As a glance from an interim result, we could find that all Devices are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such Device. But also we were able to presume that the effectiveness of Devices to the measurement reproducibility differs with the type of EUT.

    Free Register to Access Article

  • investigation on effectiveness of very high frequency line impedance stabilization network vhf lisn for measurement reproducibility
    International Symposium on Electromagnetic Compatibility, 2013
    Co-Authors: Shinichi Okuyama, Kunihiro Osabe, Katsuyuki Tanakajima, Hidenori Muramatsu

    Abstract:

    At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to the equipment under test (EUT) in the test site, i.e., do not define the common mode impedance as the terminating condition on the far end of the EUT power cable. Because of the difference in the terminating condition of the EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we investigated the effectiveness of some Devices through inter-laboratory comparison measurements in which a very high frequency line impedance stabilization network (VHF-LISN) and a common mode Absorbing Device (CMAD), one at a time, were inserted between the mains network and the EUT power cable for the purpose of defining the terminating condition. As a result, we found that both VHF-LISN and CMAD are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such Device, but we also found that their effectiveness differs with the type of EUT.

    Free Register to Access Article