The Experts below are selected from a list of 13227 Experts worldwide ranked by ideXlab platform

Hiroshi Takahashi - One of the best experts on this subject based on the ideXlab platform.

  • High performance planar lightwave circuit devices for large capacity transmission
    Optics express, 2011
    Co-Authors: Hiroshi Takahashi
    Abstract:

    Both high-density multiplexing and high-speed transmission are required for large capacity networks supporting broadband Service Penetration. Silica waveguide optical circuit technology can provide key optical devices for such systems because it has high controllability as regards optical amplitude and sufficient phase for realizing sophisticated optical interferometric circuits. This paper reviews recent progress on this technology, and reports experimental results for an ultra wideband AWG, an optical OFDM filter, a demodulator for a coherent receiver and a highly functional modulator.

  • High performance planar lightwave circuit devices for large capacity transmission
    37th European Conference and Exposition on Optical Communications, 2011
    Co-Authors: Hiroshi Takahashi
    Abstract:

    Both high density multiplexing and high speed transmission are required for large capacity networks supporting broadband Service Penetration. This paper reviews recent progress on key devices based on silica waveguide lightwave circuits for such systems.

Y. Ogura - One of the best experts on this subject based on the ideXlab platform.

  • Cost and quantity analysis of passive double-star optical-access-network facilities for broadband Service multiplexing
    Journal of Lightwave Technology, 2006
    Co-Authors: I. Sankawa, Yasuyuki Okumura, F. Yamamoto, Y. Ogura
    Abstract:

    In this paper, the authors propose the most suitable passive double-star network (PON) configuration for multiplexing more than two kinds of broadband Service by wavelength division multiplexing (WDM) in optical access networks. They calculate the cost and number of facilities in outside plant and central offices by using the latest cost trend and investigate their dependence on certain structural conditions such as the number of splits, network configuration, and fiber structure, and Service conditions such as multiplexing Service number and Service Penetration. Moreover, the required network configuration for multiplexing more than three Services was investigated. As a result, the most suitable PON network for cost-effective Service provision and fiber to the home (FTTH) deployment was determined

Sharif Ismail - One of the best experts on this subject based on the ideXlab platform.

  • health system functionality in a low income country in the midst of conflict the case of yemen
    Health Policy and Planning, 2017
    Co-Authors: Naseeb Qirbi, Sharif Ismail
    Abstract:

    Background  Although the literature on effects of armed conflict on population health is extensive, detailed assessments of effects on public health 'systems' are few. This article aims to help address this deficit through the medium of a case study on Yemen, describing health system and health outcome performance prior to the internationalisation of the conflict there in March 2015, before assessing the impact of war on health system functionality since that time. Method  Review of peer- and non-peer reviewed literature from 2005 to 2016 from academic sources, multilateral organizations, donors and governmental and non-governmental organizations, augmented by secondary data analysis. Results  Despite significant health system weaknesses and structural vulnerabilities pre-conflict, there were important improvements in selected health outcome measures in Yemen up to early 2015 (life expectancy, and infant and maternal mortality, e.g.), partly driven by a fragile health sector that was heavily reliant on out-of-pocket expenditure, and hampered by weak Service Penetration especially in rural areas. High intensity conflict has resulted in rising mortality and injury rates since March 2015, the first decline in life expectancy and increase in child and maternal mortality in Yemen for some years, and worsening levels of malnutrition. Service delivery has become increasingly challenging in the context of a funding crisis, destruction of health facilities, widespread shortages of essential medicines and equipment across the country, and governance fragmentation. Conclusion  Conflict in Yemen has resulted in humanitarian disaster on a wide scale in a short period of time, and crippled an already weak health system. Important areas of uncertainty remain, however, including the scale of health worker flight, and the extent to which alternative providers have stepped in to fill widening Service gaps as the conflict has unfolded. Planning for longer-term health system reconstruction should begin as soon as possible.

  • Health system functionality in a low-income country in the midst of conflict: the case of Yemen.
    Health Policy and Planning, 2017
    Co-Authors: Naseeb Qirbi, Sharif Ismail
    Abstract:

     Although the literature on effects of armed conflict on population health is extensive, detailed assessments of effects on public health 'systems' are few. This article aims to help address this deficit through the medium of a case study on Yemen, describing health system and health outcome performance prior to the internationalisation of the conflict there in March 2015, before assessing the impact of war on health system functionality since that time. Review of peer- and non-peer reviewed literature from 2005 to 2016 from academic sources, multilateral organizations, donors and governmental and non-governmental organizations, augmented by secondary data analysis. Despite significant health system weaknesses and structural vulnerabilities pre-conflict, there were important improvements in selected health outcome measures in Yemen up to early 2015 (life expectancy, and infant and maternal mortality, e.g.), partly driven by a fragile health sector that was heavily reliant on out-of-pocket expenditure, and hampered by weak Service Penetration especially in rural areas. High intensity conflict has resulted in rising mortality and injury rates since March 2015, the first decline in life expectancy and increase in child and maternal mortality in Yemen for some years, and worsening levels of malnutrition. Service delivery has become increasingly challenging in the context of a funding crisis, destruction of health facilities, widespread shortages of essential medicines and equipment across the country, and governance fragmentation. Conflict in Yemen has resulted in humanitarian disaster on a wide scale in a short period of time, and crippled an already weak health system. Important areas of uncertainty remain, however, including the scale of health worker flight, and the extent to which alternative providers have stepped in to fill widening Service gaps as the conflict has unfolded. Planning for longer-term health system reconstruction should begin as soon as possible. © The Author 2017. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

I. Sankawa - One of the best experts on this subject based on the ideXlab platform.

  • Cost and quantity analysis of passive double-star optical-access-network facilities for broadband Service multiplexing
    Journal of Lightwave Technology, 2006
    Co-Authors: I. Sankawa, Yasuyuki Okumura, F. Yamamoto, Y. Ogura
    Abstract:

    In this paper, the authors propose the most suitable passive double-star network (PON) configuration for multiplexing more than two kinds of broadband Service by wavelength division multiplexing (WDM) in optical access networks. They calculate the cost and number of facilities in outside plant and central offices by using the latest cost trend and investigate their dependence on certain structural conditions such as the number of splits, network configuration, and fiber structure, and Service conditions such as multiplexing Service number and Service Penetration. Moreover, the required network configuration for multiplexing more than three Services was investigated. As a result, the most suitable PON network for cost-effective Service provision and fiber to the home (FTTH) deployment was determined

Yasuyuki Okumura - One of the best experts on this subject based on the ideXlab platform.

  • cost analysis of optical access network migration scenarios to broadcast Service
    IEICE Transactions on Communications, 2007
    Co-Authors: Yasuyuki Okumura
    Abstract:

    This paper proposes the most effective deployment scenario of the passive double-star (PON) system to provide multiple broadband Services, such as high speed Internet access and broadcast Services. The deployment costs of the two major PON technologies, wavelength division multiplexing (WDM) and 10Gbps time division multiplexing (TDM), are analyzed using the latest cost trend and the most popular access network architecture. These two technologies are compared using the cost analysis results to identify the cost-effective scenarios of PON system deployment. Based on the comparison, this paper reveals that the WDM network becomes cost effective when the Service Penetration and the shift ratio becomes high.

  • Cost and quantity analysis of passive double-star optical-access-network facilities for broadband Service multiplexing
    Journal of Lightwave Technology, 2006
    Co-Authors: I. Sankawa, Yasuyuki Okumura, F. Yamamoto, Y. Ogura
    Abstract:

    In this paper, the authors propose the most suitable passive double-star network (PON) configuration for multiplexing more than two kinds of broadband Service by wavelength division multiplexing (WDM) in optical access networks. They calculate the cost and number of facilities in outside plant and central offices by using the latest cost trend and investigate their dependence on certain structural conditions such as the number of splits, network configuration, and fiber structure, and Service conditions such as multiplexing Service number and Service Penetration. Moreover, the required network configuration for multiplexing more than three Services was investigated. As a result, the most suitable PON network for cost-effective Service provision and fiber to the home (FTTH) deployment was determined