The Experts below are selected from a list of 93474 Experts worldwide ranked by ideXlab platform
Takashi Mizuochi - One of the best experts on this subject based on the ideXlab platform.
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soft decision based forward error correction for 100 gb s transport systems
IEEE Journal of Selected Topics in Quantum Electronics, 2010Co-Authors: Kiyoshi Onohara, Yoshikuni Miyata, Takashi Sugihara, Kazuo Kubo, Hideo Yoshida, Yoshiaki Konishi, Tomoka Inoue, Soichiro Kametani, Kenya Sugihara, Takashi MizuochiAbstract:Soft-decision-based forward error correction (FEC) and its practical implementation for 100 Gb/s transport systems are discussed. In applying soft-decision FEC to a digital coherent transponder, we address the configuration of the frame structure of the FEC. For dual-polarized multilevel modulation formats, the keys are having the FEC frames constructed individually for each polarization and a multilane Distribution Architecture to align each frame. We present two types of soft-decision FEC. One is the concatenation of a Reed-Solomon code and a low-density parity-check (LDPC) code with 2-bit soft decision yielding a Q limit of 7.5 dB. The other, even more powerful, is a triple-concatenated FEC, with a pair of concatenated hard-decision-based block codes further concatenated with a soft-decision-based LDPC code for 20.5% redundancy. We expect that the proposed triple-concatenated codes can achieve a Q limit of 6.4 dB and a net coding gain of 10.8 dB at a post-FEC bit error ratio of 10-15. For the practical implementation of soft-decision FEC for 100 Gb/s systems, we developed field-programmable gate array boards to emulate it. The concept of hardware emulation, with a scalable Architecture for the FEC decoder boards, is introduced by way of a pipelined Architecture.
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Soft decision FEC for 100G transport systems
Optical Fiber Communication Conference, 2010Co-Authors: Kiyoshi Onohara, Yoshikuni Miyata, Takashi Sugihara, Kazuo Kubo, Hideo Yoshida, Takashi MizuochiAbstract:A practical implementation of soft decision based FEC for 100G transport systems is discussed. The keys are a stronger coding gain using triple-concatenated FEC and a multi-lane Distribution Architecture to improve the error correction capability.
Liam Murphy - One of the best experts on this subject based on the ideXlab platform.
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A dependable multisource streaming system for peer-to-peer -based video on demand services provisioning
Multimedia Tools and Applications, 2012Co-Authors: Abdelhamid Nafaa, Baptiste Gourdin, Liam MurphyAbstract:In this article, we present the design, implementation, and analysis of a scalable VOD (Video On Demand) Distribution Architecture for IP networks. The focus of our work is on the underlying multisource streaming Architecture upon which the P2P (Peer-to-Peer) -based VOD services provisioning system relies. While multipoint-to-point multisource streaming is the core building block for a distributed VOD services provisioning system, it also introduces new reliability challenges as the streaming failure probability increases with the number of sources in a session. A major contribution of our work is the design of a suite of distinct yet complementary reliability/failover mechanisms that can be leveraged to improve the dependability of multisource streaming, and the viability of P2P-based VOD systems in general. Our work shows that the reliability/failover mechanisms can be arranged, combined, and alternated in advanced adaptation policies in order to deal with different conditions exhibited by the network. Another contribution of our work consists of implementing and assessing the performance of the different reliability mechanisms and adaptation policies in a real prototype system. We evaluate both the accuracy of streaming problems diagnosis, and the efficiency of the reliability mechanisms, in two adaptation strategies: one responsive to loss variation, and the other responsive to delay variation.
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analysis of a large scale vod Architecture for broadband operators a p2p based solution
IEEE Communications Magazine, 2008Co-Authors: Abdelhamid Nafaa, Sean Murphy, Liam MurphyAbstract:VOD services Distribution is gaining unprecedented interest from the consumer communication industry due to its growing success in both the Internet and residential broadband market. In this article we present a scalable VOD Distribution Architecture for broadband operators. The solution is based on a P2P streaming concept in which a VOD streaming session requested by a given STB is actually provisioned via a multisource streaming session. This solution has the advantage of scaling naturally with the number of STBs in the network. In this article we focus on efficiently translating the popularity Distribution into content availability in the network. Different aspects related to this issue are analyzed and challenges highlighted.
Kiyoshi Onohara - One of the best experts on this subject based on the ideXlab platform.
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soft decision based forward error correction for 100 gb s transport systems
IEEE Journal of Selected Topics in Quantum Electronics, 2010Co-Authors: Kiyoshi Onohara, Yoshikuni Miyata, Takashi Sugihara, Kazuo Kubo, Hideo Yoshida, Yoshiaki Konishi, Tomoka Inoue, Soichiro Kametani, Kenya Sugihara, Takashi MizuochiAbstract:Soft-decision-based forward error correction (FEC) and its practical implementation for 100 Gb/s transport systems are discussed. In applying soft-decision FEC to a digital coherent transponder, we address the configuration of the frame structure of the FEC. For dual-polarized multilevel modulation formats, the keys are having the FEC frames constructed individually for each polarization and a multilane Distribution Architecture to align each frame. We present two types of soft-decision FEC. One is the concatenation of a Reed-Solomon code and a low-density parity-check (LDPC) code with 2-bit soft decision yielding a Q limit of 7.5 dB. The other, even more powerful, is a triple-concatenated FEC, with a pair of concatenated hard-decision-based block codes further concatenated with a soft-decision-based LDPC code for 20.5% redundancy. We expect that the proposed triple-concatenated codes can achieve a Q limit of 6.4 dB and a net coding gain of 10.8 dB at a post-FEC bit error ratio of 10-15. For the practical implementation of soft-decision FEC for 100 Gb/s systems, we developed field-programmable gate array boards to emulate it. The concept of hardware emulation, with a scalable Architecture for the FEC decoder boards, is introduced by way of a pipelined Architecture.
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Soft decision FEC for 100G transport systems
Optical Fiber Communication Conference, 2010Co-Authors: Kiyoshi Onohara, Yoshikuni Miyata, Takashi Sugihara, Kazuo Kubo, Hideo Yoshida, Takashi MizuochiAbstract:A practical implementation of soft decision based FEC for 100G transport systems is discussed. The keys are a stronger coding gain using triple-concatenated FEC and a multi-lane Distribution Architecture to improve the error correction capability.
Marney E. Isaac - One of the best experts on this subject based on the ideXlab platform.
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Variation in fine root traits reveals nutrient-specific acquisition strategies in agroforestry systems
Plant and Soil, 2019Co-Authors: Kira A. Borden, Sean C Thomas, Marney E. IsaacAbstract:AimsChanges in root functional traits reveal important nutrient acquisition strategies, with well documented patterns in root trait expression within complex communities or along gradients of singular nutrients. In this field study, we investigate intra-root functional trait expression with six soil macro- and micro-nutrients in Theobroma cacao agroforestry systems.MethodsUsing image, chemical, and spatial analysis, the fine root Distribution, Architecture, and morphology of T. cacao were compared to localized soil nutrients on two-dimensional soil profiles with conspecific and heterospecific neighbours.ResultsFine-scale variation in soil nutrients was observed within the range of T. cacao root systems. Higher NH_4^+ and Ca^2+ was associated with greater root length and biomass densities, coupled with greater investment to individual roots, expressed as increased fine root tissue density and diameter and lower specific root length. Conversely, NO_3^− had the opposite effect. Overall, roots tended towards higher acquisitive trait values when next to a shade tree.ConclusionsPlants generally employ several concomitant and at times opposing strategies for nutrient acquisition in heterogeneous soils. We show that fine-scale root plasticity is highly linked to localized nutrient-specific and neighbour-specific effects, driving patterns of nutrient acquisition in agroforestry systems.
Giuseppe Parise - One of the best experts on this subject based on the ideXlab platform.
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Innovations in a container terminal area and electrical power Distribution for the service continuity
2016 IEEE IAS 52nd Industrial and Commercial Power Systems Technical Conference (I&CPS), 2016Co-Authors: Giuseppe Parise, F.m. Pepe, S Ricci, Luigi Parise, Chun-lien Su, P. ChavdarianAbstract:The economic efficiency in competitive container terminals promotes continuous innovations to reduce the operating costs based on the reduction of processes operating time by automated means, on the service continuity enhancement and on energy saving techniques. The increasing container number moved makes necessary the compensation of high values of energy absorbed from the utility by promoting renewable energy sources and an innovative approach of a coordinated management of the global energy absorption of all the port tenants (microgrid management). The paper deals with the relevance of system integrity aspects in the design phase and in its following management. Electrical Distribution Architecture, integrated at least by two independent sources from the utility company, has a vital impact on system availability throughout its lifecycle. Thanks to a flexible power Distribution system assisted by a prompt reaction of a qualified maintenance staff, system critical loads could be re-energized in emergency condition such as faults, maintenance operations and interruption of one energy supply from the utility company. The paper used as reference the Port of Long Beach for the data reported as example.
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wise port and business energy management port facilities electrical power Distribution
IEEE Transactions on Industry Applications, 2016Co-Authors: Giuseppe Parise, Luigi Parise, Luigi Martirano, P Chavdaria, Andrea FerranteAbstract:This paper deals with the relevance of analyzing the necessary development and of proposing a plan for research and remodeling the electrical infrastructures of port facilities. Good energy management principles, as well as electrical Distribution Architecture have a vital impact on performance of the installed system throughout its life cycle. The ports are the interface of maritime transport and are integrated in the surrounding land. They are required to arrange their electrical power Distribution system, possibly in microgrids, that is, as a “utility” system, appropriate and adequate even to power the ship from shore. Harbors must have an energy master plan and their areas have to be considered as a unique customer. The energy management of a port area may be a great business opportunity for the port authority, which until now was not, involving different stakeholders who may benefit from service, including the same power utility company that benefits from the optimization and control of the energy flows.
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electrical Distribution for a reliable data center
IEEE Transactions on Industry Applications, 2013Co-Authors: Giuseppe Parise, Luigi PariseAbstract:For the reliability of data centers, the electrical Distribution Architecture has a vital impact on performances throughout its life cycle. Special standards establish tier classifications for the site infrastructures. The switchboard (SWB) design needs to plan the load balancing, the future expansion and rehabilitation of the Distribution (road map), and periodic maintenances without loss service continuity. The protection must be coordinated for the selectivity of the fault on the final circuits to ensure service continuity of the whole system. Equipment like electronic components exhibits excessive inrush currents at start-up that request a rating current value higher than the load current value. Maintaining for many years a protection coordination tolerant to the initial inrush current, it is a technical inadmissible inaccuracy for the data center service. The failure of a final circuit not adequately selected and cleared can cause an impact on the fault selectivity on the SWB section or all the uninterruptible power system supply. Starting systems for equipment should be adopted to solve the problem of inrush current and to allow an adequate protection coordination for the long service of the data center.
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Architecture Impact on Integrity of Electrical Installations: Cut&Tie Rule, Ring Configuration, Floating Node
IEEE Transactions on Industry Applications, 2009Co-Authors: Giuseppe Parise, Erling Hesla, Rasheek RifaatAbstract:An electrical Distribution Architecture has a vital impact on the performance of an installed system throughout its lifecycle. The Architecture of an installation involves the configuration, the choice of power sources (utility and alternate power source), the definition of the different Distribution levels, and the choice of equipment. Previous papers have introduced a language program for analyzing and transcribing the instructions of the safety procedures for each working zone and of the integrity procedures for each source node versus the loss of service continuity (the Parise program). Each node presents a kit of instructions as a logic gene, describing a complete and reversible evolution of the component switching means from an opening status to a closing one. This paper deals with the Architecture of a power system and the combination of procedures in the operation on a nodes system. It will show the impact of the Architecture on the comprehensive procedures for a complex system. To enhance the integrity of power system analysis and operation, the design could adopt the cut&tie rule, introducing ring configuration and floating nodes. The suggested advanced approach assists in the elaboration of the procedures for switching from one set or configuration of a power system to another and will help the training of operators in defining the instructions to be used in the development and the operating of each power system.
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Architecture impact on integrity of electrical installations: Cut&tie rule, ring configuration, floating node
2008 IEEE IAS Industrial and Commercial Power Systems Technical Conference, 2008Co-Authors: Giuseppe Parise, Erling Hesla, Rasheek RifaatAbstract:The electrical Distribution Architecture has a vital impact on performance of the installed system throughout its lifecycle. The Architecture of an installation involves the configuration, the choice of power sources (utility and alternate power source) the definition of different Distribution levels and the choice of equipment. Previous papers have introduced a language-program for analyzing and transcribing the instructions of safety procedures for each working zone WZ and of integrity procedures for each sources node versus the loss of service continuity (Parise's program). Each node presents a kit of instructions as a logic gene describing a complete and reversible evolution of the component switching means from a opening status to a closing one. This paper deals with the Architecture of a power system and the combination of procedures in the operation on a nodes system. It will show the impact of the Architecture on the comprehensive procedures for a complex system. To enhance the integrity of power system analysis and operation, the design could adopt the cut and tie rule, introducing ring configuration and floating nodes. The suggested advanced approach assists in the elaboration of the procedures for switching from one set or configuration of a power system to another and will help the training of operators in defining the instructions to be used in the development and the operating of each power system.