The Experts below are selected from a list of 38562 Experts worldwide ranked by ideXlab platform
Osama Farrag - One of the best experts on this subject based on the ideXlab platform.
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adaptive Security Provision for increased energy efficiency in wireless sensor networks
Local Computer Networks, 2009Co-Authors: Mohamed Younis, Nick Krajewski, Osama FarragAbstract:This paper introduces a novel optimization strategy for increasing the resource efficiency and Security of data routing in a wireless sensor network. Most secure routing schemes found in the literature Provision Security at the highest level by involving sophisticated data encryption with a large key. This imposes lots of overhead both in computation, while performing the encryption and decryption, and in communication due to bit padding. The proposed optimization approach strives to adapt the Security measures to the trust level on the nodes on the path and factors in the Security-related overhead in the link cost. In addition, a novel path rotation scheme is proposed to enable the use of resource-efficient Security measures without risking an increase in vulnerability. The applicability of the proposed optimization is validated using the Ad hoc On-Demand Multipath Distance Vector (AOMDV) routing protocol and its performance advantage is confirmed via ns2 simulation experiments.
Bekele Shiferaw - One of the best experts on this subject based on the ideXlab platform.
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land degradation drought and food Security in a less favoured area in the ethiopian highlands a bio economic model with market imperfections
Agricultural Economics, 2004Co-Authors: Stein T Holden, Bekele ShiferawAbstract:This paper presents a bio-economic model of Andit Tid, a severely degraded crop-livestock farming system with high population density and good market access in the highlands of Ethiopia. Land degradation, population growth, stagnant technology, and drought threaten food Security in the area. Drought or weather risk appears to have increased in recent years. The bio-economic model is used to analyse the combined effects of land degradation, population growth, market imperfections and increased risk of drought on household production, welfare and food Security. We find that the indirect effects of drought on household welfare through the impact on crop and livestock prices are larger than the direct production effects of drought. Provision and adoption of credit for fertiliser, although risky in itself, may lead to increased grain production and improved household welfare and food Security. Provision of credit may have a negative effect on conservation incentives but this effect may be mitigated by linking a conservation requirement to the Provision of credit for fertiliser. © 2003 Elsevier B.V. All rights reserved.
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land degradation drought and food Security in a less favoured area in the ethiopian highlands a bio economic model with market imperfections
Agricultural Economics, 2004Co-Authors: Stein T Holden, Bekele ShiferawAbstract:Abstract This paper presents a bio-economic model of Andit Tid, a severely degraded crop–livestock farming system with high population density and good market access in the highlands of Ethiopia. Land degradation, population growth, stagnant technology, and drought threaten food Security in the area. Drought or weather risk appears to have increased in recent years. The bio-economic model is used to analyse the combined effects of land degradation, population growth, market imperfections and increased risk of drought on household production, welfare and food Security. We find that the indirect effects of drought on household welfare through the impact on crop and livestock prices are larger than the direct production effects of drought. Provision and adoption of credit for fertiliser, although risky in itself, may lead to increased grain production and improved household welfare and food Security. Provision of credit may have a negative effect on conservation incentives but this effect may be mitigated by linking a conservation requirement to the Provision of credit for fertiliser.
Goran Strbac - One of the best experts on this subject based on the ideXlab platform.
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capacity value of energy storage in distribution networks
Journal of energy storage, 2018Co-Authors: Ioannis Konstantelos, Goran StrbacAbstract:Abstract Security of supply in electricity distribution networks has been traditionally delivered by conventional assets such as transformers and circuits to supply energy to consumers. Although non-network solutions, such as energy storage (ES), can also be used to provide Security of supply by carrying out peak shaving and maintaining supply for the duration of a network outage, present network design standards do not provide a framework for quantifying their Security contribution and corresponding capacity value. Given the fundamentally different operating principles of ES, it is imperative to develop novel methodologies for assessing its contribution to Security of supply and enable a level playing field to be established for future network planning. To this end, a novel probabilistic methodology based on chronological Monte Carlo simulations is developed for computing the Effective Load Carrying Capability (ELCC) of an energy storage plant. Substantial computational speed-up is achieved through event-based modelling and decomposing between energy and power constraints. The paper undertakes, for the first time, the in-depth analysis of key factors that can affect ES Security contribution; plant and network outage frequency and duration, network redundancy level, demand shape, islanding operation capability and ES availability. ES capacity value is shown to decrease in networks with an unreliable connection to the grid; time to restore supply is shown to be more important that frequency of faults. Capacity value increases in cases of peaky demand profiles, while the ability to operate in islanded conditions is shown to be a critical factor. These findings highlight the need for sophisticated network design standards. The proposed methodology enables planners to consider ES solutions and allows network and non-network assets to compete on an equal basis for Security Provision.
Mohamed Younis - One of the best experts on this subject based on the ideXlab platform.
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adaptive Security Provision for increased energy efficiency in wireless sensor networks
Local Computer Networks, 2009Co-Authors: Mohamed Younis, Nick Krajewski, Osama FarragAbstract:This paper introduces a novel optimization strategy for increasing the resource efficiency and Security of data routing in a wireless sensor network. Most secure routing schemes found in the literature Provision Security at the highest level by involving sophisticated data encryption with a large key. This imposes lots of overhead both in computation, while performing the encryption and decryption, and in communication due to bit padding. The proposed optimization approach strives to adapt the Security measures to the trust level on the nodes on the path and factors in the Security-related overhead in the link cost. In addition, a novel path rotation scheme is proposed to enable the use of resource-efficient Security measures without risking an increase in vulnerability. The applicability of the proposed optimization is validated using the Ad hoc On-Demand Multipath Distance Vector (AOMDV) routing protocol and its performance advantage is confirmed via ns2 simulation experiments.
Stein T Holden - One of the best experts on this subject based on the ideXlab platform.
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land degradation drought and food Security in a less favoured area in the ethiopian highlands a bio economic model with market imperfections
Agricultural Economics, 2004Co-Authors: Stein T Holden, Bekele ShiferawAbstract:This paper presents a bio-economic model of Andit Tid, a severely degraded crop-livestock farming system with high population density and good market access in the highlands of Ethiopia. Land degradation, population growth, stagnant technology, and drought threaten food Security in the area. Drought or weather risk appears to have increased in recent years. The bio-economic model is used to analyse the combined effects of land degradation, population growth, market imperfections and increased risk of drought on household production, welfare and food Security. We find that the indirect effects of drought on household welfare through the impact on crop and livestock prices are larger than the direct production effects of drought. Provision and adoption of credit for fertiliser, although risky in itself, may lead to increased grain production and improved household welfare and food Security. Provision of credit may have a negative effect on conservation incentives but this effect may be mitigated by linking a conservation requirement to the Provision of credit for fertiliser. © 2003 Elsevier B.V. All rights reserved.
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land degradation drought and food Security in a less favoured area in the ethiopian highlands a bio economic model with market imperfections
Agricultural Economics, 2004Co-Authors: Stein T Holden, Bekele ShiferawAbstract:Abstract This paper presents a bio-economic model of Andit Tid, a severely degraded crop–livestock farming system with high population density and good market access in the highlands of Ethiopia. Land degradation, population growth, stagnant technology, and drought threaten food Security in the area. Drought or weather risk appears to have increased in recent years. The bio-economic model is used to analyse the combined effects of land degradation, population growth, market imperfections and increased risk of drought on household production, welfare and food Security. We find that the indirect effects of drought on household welfare through the impact on crop and livestock prices are larger than the direct production effects of drought. Provision and adoption of credit for fertiliser, although risky in itself, may lead to increased grain production and improved household welfare and food Security. Provision of credit may have a negative effect on conservation incentives but this effect may be mitigated by linking a conservation requirement to the Provision of credit for fertiliser.