Embedded Network Test-Bed for Validating Real-Time Control Algorithms to Ensure Optimal Time Domain Performance

The paper presents a Stateflow based network test-bed to validate real-time optimal control algorithms. Genetic Algorithm (GA) based time domain performance index minimization is attempted for tuning of PI controller to handle a balanced lag and delay type First Order Plus Time Delay (FOPTD) process over network. The tuning performance is validated on a real-time communication network with artificially simulated stochastic delay, packet loss and out-of order packets characterizing the network.Comment: 6 pages, 12 figure

Co-simulation of a Low-Voltage Utility Grid Controlled over IEC 61850 protocol

International audienceThis paper presents a co-simulation model using MATLAB® toolboxes to illustrate an interaction between the communication system and the energy grid, coherent with the concept of smart grid that employs IEC 61850 communication standard. The MMS (Manufacturing Message Specification) protocol supported by IEC 61850, based on TCP/IP is used for the vertical communication between the Supervisory and Data Acquisition (SCADA) system and Intelligent Electronic Devices (IEDs) embedding the local control of different parts of the smart grid. In this paper an IED supporting the power control of a photovoltaic (PV) plant connected to a low-voltage (LV) utility grid is considered. Communication system consisting of the transport layer and a router placed on the network layer is modeled as an event driven system using SimEvents® toolbox and energy grid is modeled as a time-driven system using SimPowerSystems® toolbox. Co-simulation results are obtained by combining different communication scenarios and time-varying irradiance scenarios for thee PV plant when the PV plant is required to provide a certain power in response to a power reference received from SCADA over the communication network. The analysis aims at illustrating the impact that stochastic behavior and delays due to network communication have on the global system behavior

Hybrid DES-based Vehicular Network Simulator with Multichannel Operations

Vehicular Ad-hoc Network (VANET) is considered to be a viable technology for inter- vehicle communications for the purpose of improving road safety and efficiency. The En- hanced Distribution Channel Access (EDCA) mechanism and multichannel operations are introduced to ensure the Quality of Service (QoS). Therefore, it is necessary to create an accurate vehicular network simulator that guarantees the vehicular communications will work as described in the protocols. A comprehensive vehicular network simulator should consider the interaction between mobility models and network protocols. In this dissertation, a novel vehicular network simulation environment, VANET Toolbox, designed using discrete-event system (DES) is presented. The APP layer DES Module of the proposed simulator integrates vehicular mo- bility operations with message generation functions. The MAC layer DES module supports single channel and multichannel EDCA operations. The PHY layer DES module supports bit-level processing. Compared with packet-based simulator such as NS-3, the proposed PHY layer is more realistic and accurate. The EDCA scheme is evaluated and compared with the traditional Carrier-Sensing Mul- tiple Access (CSMA) scheme, with the simulations proving that data with different priorities can coexist in the same channel. The multichannel operation for the EDCA scheme is also analyzed in this dissertation. The multichannel switching operation and coordination may cause packet dropping or increased latency to the communication. The simulations show that with heavy network traffic, multichannel communication performs better than single channel communication. From the perspective of safety-related messages, the multichannel operation is able to isolate the interference from the non-safety messages in order to achieve a better packet delivery rate and latency. On the other hand, the non-safety messages can achieve high throughput with reasonable latency from multichannel communication under heavy load traffic scenario

On modelling network coded ARQ-based channels

Network coding (NC) has been an attractive research topic in recent years as a means of offering a throughput improvement, especially in multicast scenarios. The throughput gain is achieved by introducing an algebraic method for combining multiple input streams of packets which are addressing one output port at an intermediate node. We present a practical implementation of network coding in conjunction with error control schemes, namely the Stop-and-Wait (SW) and Selective Repeat (SR) protocols. We propose a modified NC scheme and apply it at an intermediate SW ARQ-based link to reduce ARQ control signals at each transmission. We further extend this work to investigate the usefulness of NC in the Butterfly multicast network which adopts the SR ARQ protocol as an error control scheme. We validate our throughput analysis using a relatively recent discrete-event simulator, SimEvents®. The results show that the proposed scheme offers a throughput advantage of at least 50% over traditional SW ARQ, and that this is particularly noticeable in the presence of high error rates. In the multicast network, however, simulation results show that when compared with the traditional scheme, NC-SR ARQ can achieve a throughput gain of between 2% and 96% in a low bandwidth channel and up to 19% in a high bandwidth channel with errors

Cognitive Sensor Platform

This paper describes a platform that is used to build embedded sensor systems for low energy implantable applications. One of the key characteristics of the platform is the ability to reason about the environment and dynamically modify the operational parameters of the system. Additionally the platform provides to ability to compose application specific sensor systems using a novel computational element that directly supports a synchronous-dataflow (SDF) programming paradigm. Cognition in the context of a sensor platform is defined as the “process of knowing, including aspects of awareness, perception, reasoning, and judgment”.DOI:http://dx.doi.org/10.11591/ijece.v4i4.568

Performance Analysis of Simulation-based Multi-objective Optimization of Bridge Construction Processes Using High Performance Computing

Bridges constitute a crucial component of urban highways due to the complexity and uncertain nature of their construction process. Simulation is an alternative method of analyzing and planning the construction processes, especially the ones with repetitive and cyclic nature, and it helps managers to make appropriate decisions. Furthermore, there is an inverse relationship between the cost and time of a project and finding a proper trade-off between these two key elements using optimization methods is important. Thus, the integration of simulation models with optimization techniques leads to an advancement in the decision making process. In addition, the large number of resources required in complex and large scale bridge construction projects results in a very large search space. Therefore, there is a need for using parallel computing in order to reduce the computational time of the simulation-based optimization. Most of the construction simulation tools need an integration platform to be combined with optimization techniques. Also, these simulation tools are not usually compatible with Linux environment which is used in most of the massive parallel computing systems or clusters. In this research, an integrated simulation-based optimization framework is proposed within one platform to alleviate those limitations. A master-slave (or global) parallel Genetic Algorithm (GA) is used as a parallel computing technique to decrease the computation time and to efficiently use the full capacity of the computer. In addition, sensitivity analysis is applied to identify the promising configuration for GA and analyzing the impact of GA parameters on the overall performance of the specific simulation-based optimization problem used in this research. Finally, a case study is implemented and tested on a server machine as well as a cluster to explore the feasibility of the proposed approach. The results of this research showed better performance of the proposed framework in comparison with other GA optimization techniques from the points of view of the quality of the optimum solutions and the computation time. Also, acceptable improvements in the computation time were achieved for both deterministic and probabilistic simulation models using master-salve parallel paradigm (8.32 and 20.3 times speedups were achieved using 12 cores, respectively). Moreover, performing the proposed framework on multiple nodes using a cluster system led to 31% saving on the computation time on average. Furthermore, the GA was tuned using sensitivity analyses which resulted in the best parameters (500 generations, population size of 200 and 0.7 as the crossover probability)

Proposal of a complementary method of data compression by discrete event methodology applied at a low level of abstraction

Orientadores: Edson Moschim, Yuzo IanoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: O presente trabalho implementa um modelo baseado em eventos discretos aplicados em um baixo nível de abstração em um sistema de telecomunicações chamado método híbrido, sendo usado o ambiente de simulação Simulink® do software Matlab®. Com o objetivo de melhorar a transmissão da informação em sistemas de telecomunicações e contribuir para a área de estudo, em ambiente de simulação é proposto um processo de pré-codificação de bits baseada na aplicação de eventos discretos no sinal antes do processo de modulação. A proposta traz uma abordagem diferente do que se é usualmente feito, na qual a transmissão de sinal no canal é realizada no domínio discreto com a implementação de entidades discretas no processo de geração de bits, tendo como ênfase o bit zero. Na simulação são considerados formatos de modulação avançada para transmissão de sinal em um canal AWGN. Os resultados mostram melhorias na utilização da memória e no desempenho computacional, sendo de 9 a 34%, assim como também ao tempo de simulação. Sendo assim, a extensão desses resultados, tem um forte impacto no melhoramento de métodos realizados em camadas mais altas, já que a proposta atua na camada físicaAbstract: The present work implements a model based on discrete events applied at a low level of abstraction in a telecommunication system named hybrid method, being used the Simulink® simulation environment of the Matlab® software. With the objective of improving the transmission of information in telecommunication systems and contribute to the study area, in simulation environment is proposed a pre-coding process of bits based in the application of discrete events in the signal before of the modulation process. The proposal brings a different approach of usual technical, in which the signal transmission on the channel is realized in the discrete domain with the implementation of discrete entities in the process of bit generation having as emphasis the zero bit. In the simulation are considered advanced modulation formats for signal transmission in an AWGN channel. The results show improvements in memory utilization and computational performance, from 9 to 34%, as well as simulation time. Thus, the extension of these results has a strong impact on the improvement of methods performed in higher layers, since the proposal acts on the physical layerMestradoEletrônica, Microeletrônica e OptoeletrônicaMestre em Engenharia Elétrica132495/2016-3CNP

Distance-based Cluster Head Election for Mobile Sensing

Energy-efficient, fair, stochastic leader-selection algorithms are designed for mobile sensing scenarios which adapt the sensing strategy depending on the mobile sensing topology. Methods for electing a cluster head are crucially important when optimizing the trade-off between the number of peer-to- peer interactions between mobiles and client-server interactions with a cloud-hosted application server. The battery-life of mobile devices is a crucial constraint facing application developers who are looking to use the convergence of mobile computing and cloud computing to perform environmental sensing. We exploit the mobile network topology, specifically the location of mobiles with respect to the gateway device, to stochastically elect a cluster head so that (1) different energy saving policies can be implemented and (2) battery lifetime is increased given an energy efficiency policy, in a fair way. We demonstrate that the battery usage can be made more fair by reducing the difference in battery life-time of mobiles by up to 66%