The Experts below are selected from a list of 141576 Experts worldwide ranked by ideXlab platform
Pierre-philippe Combes - One of the best experts on this subject based on the ideXlab platform.
-
Transport costs measures determinants and regional policy implications for france
Journal of Economic Geography, 2005Co-Authors: Pierre-philippe Combes, Miren LafourcadeAbstract:We develop a methodology to accurately compute Transport costs. Based on the real Transport network, our measure encompasses the characteristics of infrastructure, vehicle and energy used, as well as labor, insurance, tax and general charges borne by Transport carriers. Computed for the 341 French employment areas, road Transport shipments and the period 1978--1998, this new measure is compared to alternative ones such as great circle distance, real distance, or real time. We conclude that these proxies do a very good job in capturing Transport costs in cross-section analysis. However, important discrepancies limit the possibility of using them in time series analysis. Moreover, our measure allows us to identify the policies that most impact Transport costs. We show that Transport Technology and market structure are responsible for most of the Transport cost decrease. Infrastructure improvements only condition the spatial distribution of the gains. Finally, some implications for researchers and regional policy makers are derived. Copyright 2005, Oxford University Press.
-
Transport Costs: Measures, Determinants and Regional Policy Implications for France
Journal of Economic Geography, 2005Co-Authors: Miren Lafourcade, Pierre-philippe CombesAbstract:We develop a methodology to accurately compute Transport costs. Based on the real Transport network, our measure encompasses the characteristics of infrastructure, vehicle and energy used, as well as labor, insurance, tax and general charges borne by Transport carriers. Computed for the 341 French employment areas, road Transport shipments and the period 1978-1998, this new measure is compared to alternative ones such as great circle distance, real distance, or real time. We conclude that these proxies do a very good job in capturing Transport costs in cross-section analysis. However, important discrepancies limit the possibility of using them in time series analysis. Moreover, our measure allows us to identify the policies that most impact Transport costs. We show that Transport Technology and market structure are responsible for most of the Transport cost decrease. Infrastructure improvements only condition the spatial distribution of the gains. Finally, some implications for researchers and regional policy makers are derived.
Miren Lafourcade - One of the best experts on this subject based on the ideXlab platform.
-
Transport costs measures determinants and regional policy implications for france
Journal of Economic Geography, 2005Co-Authors: Pierre-philippe Combes, Miren LafourcadeAbstract:We develop a methodology to accurately compute Transport costs. Based on the real Transport network, our measure encompasses the characteristics of infrastructure, vehicle and energy used, as well as labor, insurance, tax and general charges borne by Transport carriers. Computed for the 341 French employment areas, road Transport shipments and the period 1978--1998, this new measure is compared to alternative ones such as great circle distance, real distance, or real time. We conclude that these proxies do a very good job in capturing Transport costs in cross-section analysis. However, important discrepancies limit the possibility of using them in time series analysis. Moreover, our measure allows us to identify the policies that most impact Transport costs. We show that Transport Technology and market structure are responsible for most of the Transport cost decrease. Infrastructure improvements only condition the spatial distribution of the gains. Finally, some implications for researchers and regional policy makers are derived. Copyright 2005, Oxford University Press.
-
Transport Costs: Measures, Determinants and Regional Policy Implications for France
Journal of Economic Geography, 2005Co-Authors: Miren Lafourcade, Pierre-philippe CombesAbstract:We develop a methodology to accurately compute Transport costs. Based on the real Transport network, our measure encompasses the characteristics of infrastructure, vehicle and energy used, as well as labor, insurance, tax and general charges borne by Transport carriers. Computed for the 341 French employment areas, road Transport shipments and the period 1978-1998, this new measure is compared to alternative ones such as great circle distance, real distance, or real time. We conclude that these proxies do a very good job in capturing Transport costs in cross-section analysis. However, important discrepancies limit the possibility of using them in time series analysis. Moreover, our measure allows us to identify the policies that most impact Transport costs. We show that Transport Technology and market structure are responsible for most of the Transport cost decrease. Infrastructure improvements only condition the spatial distribution of the gains. Finally, some implications for researchers and regional policy makers are derived.
Dimitra Simeonidou - One of the best experts on this subject based on the ideXlab platform.
-
cross layer optimization of network resource virtualization in ip over o ofdm networks
IEEE\ OSA Journal of Optical Communications and Networking, 2016Co-Authors: Ali Hammad, Reza Nejabati, Dimitra SimeonidouAbstract:Optical orthogonal frequency division multiplexing (O-OFDM) is a promising Transport Technology for virtualization and bandwidth sharing over highcapacity optical fibers. In this paper, we propose an IPover O-OFDM optical network architecture utilizing network virtualization across IP and optical layers. A design goal of this architecture is to provide dynamicity and flexibility in addition to the high capacity required to support multirate traffic with various quality of service requirements. In this architecture, optimized allocation of optical resources to virtual optical networks that accommodate the traffic of IP networks is considered. O-OFDM is utilized to allocate a set of low-rate contiguous subcarriers to each traffic connection represented by a virtual optical link. In addition, we study virtualization of IP network resources (i.e., routers and bandwidth capacities of links) in order to compose several customized virtual IP networks. Furthermore, coordination between IP and optical network virtualization mechanisms is investigated in order to achieve the required optimization of network resource virtualization across the different domains. For this purpose, a novel replanning approach is proposed and is aimed to adapt the resources allocated for virtual optical networks based on the requirements of an IP layer.
-
experimental demonstration of an openflow based software defined optical network employing packet fixed and flexible dwdm grid technologies on an international multi domain testbed
Optics Express, 2013Co-Authors: Mayur Channegowda, Dimitra Simeonidou, Reza Nejabati, Rashidi M Fard, Shuping Peng, N Amaya, Georgios Zervas, R Vilalta, Ramon Casellas, R MartinezAbstract:Software defined networking (SDN) and flexible grid optical Transport Technology are two key technologies that allow network operators to customize their infrastructure based on application requirements and therefore minimizing the extra capital and operational costs required for hosting new applications. In this paper, for the first time we report on design, implementation & demonstration of a novel OpenFlow based SDN unified control plane allowing seamless operation across heterogeneous state-of-the-art optical and packet Transport domains. We verify and experimentally evaluate OpenFlow protocol extensions for flexible DWDM grid Transport Technology along with its integration with fixed DWDM grid and layer-2 packet switching.
-
The application of optical packet switching in future communication networks
Communications Magazine IEEE, 2001Co-Authors: Michael Joseph Mahony, David K. Hunter, Dimitra Simeonidou, Anna TzanakakiAbstract:Telecommunication networks are experiencing a dramatic increase in demand for capacity, much of it related to the exponential takeup of the Internet and associated services. To support this demand economically, Transport networks are evolving to provide a reconfigurable optical layer which, with optical cross-connects, will realize a high-bandwidth flexible core. As well as providing large capacity, this new layer will be required to support new services such as rapid provisioning of an end-to-end connection under customer control. The first phase of network evolution, therefore, will provide a circuit-switched optical layer characterized by high capacity and fast circuit provisioning. In the longer term, it is currently envisaged that the bandwidth efficiency associated with optical packet switching (a Transport Technology that matches the bursty nature of multimedia traffic) will be required to ensure economic use of network resources. This article considers possible network application scenarios for optical packet switching. In particular, it focuses on the concept of an optical packet router as an edge network device, functioning as an interface between the electronic and optical domains. In this application it can provide a scalable and efficient IP traffic aggregator that may provide greater flexibility and efficiency than an electronic terabit router with reduced cost. The discussion considers the main technical issues relating to the concept and its implementation
Henrique Andrade - One of the best experts on this subject based on the ideXlab platform.
-
evaluation of a high volume low latency market data processing system implemented with ibm middleware
Software - Practice and Experience, 2012Co-Authors: Yoonho Park, Senthil Nathan, Richard Pervin King, Wesley Most, Henrique AndradeAbstract:A stock market data processing system that can handle high data volumes at low latencies is critical to market makers. Such systems play a critical role in algorithmic trading, risk analysis, market surveillance, and many other related areas. The current systems tend to use specialized software and custom processors. We show that such a system can be built with general-purpose middleware and run on commodity hardware. The middleware we use is IBM System S which includes Transport Technology from IBM WebSphere MQ Low Latency Messaging (LLM). Our performance evaluation consists of two parts. First, we determined the effectiveness of each system optimization that the hardware and software infrastructure makes available. These optimizations were implemented at all software levels--application, middleware, and operating system. Second, we evaluated our system on different hardware platforms.
-
Implementing a high-volume, low-latency market data processing system on commodity hardware using IBM middleware
Proc. of the 2nd Workshop on High Performance Computational Finance - WHPCF '09, 2009Co-Authors: Xiaolan J. Zhang, Randall Schnier, Philippe Selo, Michael Spicer, John Morar, C. Venkatramani, Bugra Gedik, Henrique Andrade, Senthil Nathan, Richard King, Raju Pavuluri, Volkmar Uhlig, Yoonho Park, Edward PringAbstract:A stock market data processing system that can handle high data volumes at low latencies is critical to market makers. Such systems play a critical role in algorithmic trading, risk analysis, market surveillance, and many other related areas. We show that such a system can be built with general-purpose middleware and run on commodity hardware. The middleware we use is IBM System S, which has been augmented with Transport Technology from IBM WebSphere MQ Low Latency Messaging. Using eight commodity x86 blades connected with Ethernet and Infiniband, this system can achieve 80 μsec average latency at 3 times the February 2008 options market data rate and 206 μsec average latency at 15 times the February 2008 rate.
Henry D Jacoby - One of the best experts on this subject based on the ideXlab platform.
-
Technology detail in a multisector cge model Transport under climate policy
Energy Economics, 2005Co-Authors: Andreas Schafer, Henry D JacobyAbstract:A set of three analytical models is used to study the imbedding of specific Transport technologies within a multisector, multiregion evaluation of constraints on greenhouse emissions. The key parameters of a computable general equilibrium (CGE) model are set to mimic the behavior of a model of modal splits and a market allocation (MARKAL) model of household and industry Transport activities. In simulation mode, the CGE model provides key economic data to an analysis of the details of Transport Technology under policy restraint. Results focus on the penetration of new automobile technologies into the vehicle market.
