Design and implementation of ultra-low-power sensor interface circuits for ECG acquisition

Master'sMASTER OF ENGINEERIN

Control evaluation in a LVoD system based on a peer-to-peer multicast scheme

Providing Quality of Service (QoS) in video on demand systems (VoD) is a challenging problem. In this paper, we analyse the fault tolerance on a P2P multicast delivery scheme, called Patch Collaboration Manager / Multicast Channel Distributed Branching (PCM/MCDB) [13]. This scheme decentralizes the delivery process between clients and scales the VoD server performance. PCM/MCDB synchronizes a group of clients in order to create local network channels to replace on-going multicast channels from the VoD server. Using the P2P paradigm supposes facing the challenge of how often peers connect and disconnect from the system. To address this problem, a centralized mechanism is able to replace the failed client. We evaluate the failure management process of the centralized scheme in terms of the overhead injected into the network and analyse the applicability of a distributed approach to managing the process. Analytical models are developed for centralized and distributed approaches. Their behaviour are compared in order to evaluate whether the distributed scheme can improve the fault management process, in terms of reducing server load and generating better scalability.Proporcionar Calidad de Servicio (QoS) en sistemas de Vídeo bajo Demanda (VoD) es un problema desafiador. En este artículo, analizamos la tolerancia a fallos en un esquema de envío de informaciones, basado en comunicaciones multicast y colaboraciones P2P, denominado PCM/MCDB [13]. El esquema descentraliza el proceso de envío de información entre los clientes y escala las prestaciones del servidor de VoD. PCM/MCDB sincroniza un grupo de clientes con objeto de crear canales de redes locales para reemplazar canales multicast en curso del servidor. La aplicación del paradigma P2P supone cómo afrontar el problema de la conexión y desconexión de clientes del sistema. Para resolver este problema, un mecanismo centralizado es capaz de reemplazar el cliente fallido. En el trabajo evaluamos el proceso de gestión de fallos del esquema centralizado en términos del flujo de informaciones insertado en la red y analizamos la aplicabilidad de un esquema distribuido para el proceso de gestión. Modelos analíticos son desarrollados para las aproximaciones centralizada y distribuida. Sus comportamientos son comparados con objeto de evaluar si un esquema distribuido puede mejorar el proceso de gestión de fallos desde el punto de vista de reducir la carga del servidor y proporcionar mejor escalabilidad.VIII Workshop de Procesamiento Distribuido y ParaleloRed de Universidades con Carreras en Informática (RedUNCI

Control evaluation in a LVoD system based on a peer-to-peer multicast scheme

Providing Quality of Service (QoS) in video on demand systems (VoD) is a challenging problem. In this paper, we analyse the fault tolerance on a P2P multicast delivery scheme, called Patch Collaboration Manager / Multicast Channel Distributed Branching (PCM/MCDB) [13]. This scheme decentralizes the delivery process between clients and scales the VoD server performance. PCM/MCDB synchronizes a group of clients in order to create local network channels to replace on-going multicast channels from the VoD server. Using the P2P paradigm supposes facing the challenge of how often peers connect and disconnect from the system. To address this problem, a centralized mechanism is able to replace the failed client. We evaluate the failure management process of the centralized scheme in terms of the overhead injected into the network and analyse the applicability of a distributed approach to managing the process. Analytical models are developed for centralized and distributed approaches. Their behaviour are compared in order to evaluate whether the distributed scheme can improve the fault management process, in terms of reducing server load and generating better scalability.Proporcionar Calidad de Servicio (QoS) en sistemas de Vídeo bajo Demanda (VoD) es un problema desafiador. En este artículo, analizamos la tolerancia a fallos en un esquema de envío de informaciones, basado en comunicaciones multicast y colaboraciones P2P, denominado PCM/MCDB [13]. El esquema descentraliza el proceso de envío de información entre los clientes y escala las prestaciones del servidor de VoD. PCM/MCDB sincroniza un grupo de clientes con objeto de crear canales de redes locales para reemplazar canales multicast en curso del servidor. La aplicación del paradigma P2P supone cómo afrontar el problema de la conexión y desconexión de clientes del sistema. Para resolver este problema, un mecanismo centralizado es capaz de reemplazar el cliente fallido. En el trabajo evaluamos el proceso de gestión de fallos del esquema centralizado en términos del flujo de informaciones insertado en la red y analizamos la aplicabilidad de un esquema distribuido para el proceso de gestión. Modelos analíticos son desarrollados para las aproximaciones centralizada y distribuida. Sus comportamientos son comparados con objeto de evaluar si un esquema distribuido puede mejorar el proceso de gestión de fallos desde el punto de vista de reducir la carga del servidor y proporcionar mejor escalabilidad.VIII Workshop de Procesamiento Distribuido y ParaleloRed de Universidades con Carreras en Informática (RedUNCI

Stochastic Optimization of Coupled Power Distribution-Urban Transportation Network Operations with Autonomous Mobility on Demand Systems

Autonomous mobility on demand systems (AMoDS) will significantly affect the operation of coupled power distribution-urban transportation networks (PTNs) by the optimal dispatch of electric vehicles (EVs). This paper proposes an uncertainty method to analyze the operational states of PTNs with AMoDS. First, a PTN operation framework is designed considering the controllable EVs dispatched by AMoDS as well as the uncontrollable driving behaviors of other vehicle users. Then, a bi-level power-traffic flow (PTF) model is proposed to characterize the interaction of power distribution networks (PDNs) and urban transportation networks (UTNs). In the upper level, a social optimum model is established to minimize the operating cost of PDNs and UTNs embedded with controllable EVs. In the lower level, a stochastic user equilibrium (SUE) model is established to minimize the operating cost of uncontrollable EVs and gasoline vehicles (GVs) in UTNs. Finally, a probabilistic PTF analysis method is developed to evaluate PTN operations under environmental and human uncertainties. A regional sensitivity analysis method is proposed to identify the critical uncertainties and quantify the impacts of their distribution ranges on PTN operations. The effectiveness of the proposed method is verified by the PTN consisting of a 21-bus PDN and a 20-node UTN.Comment: 10 pages, 13 figure

Galactic diffuse gamma-ray emission from GeV to PeV energies in light of up-to-date cosmic ray measurements

The diffuse gamma-ray emission between 10 and 1000 TeV from the Galactic plane was recently measured by the Large High Altitude Air Shower Observatory (LHAASO). These observations will help tremendously in constraining the propagation and interaction of cosmic rays in the Milky Way. Additionally, new measurements of CR spectra reach a very high precision up to 100 TeV energies, revealing multiple spectral structures of various species. In this work, we confront the model prediction of the diffuse gamma-ray emission, based on up-to-date measurements of the local cosmic ray spectra and simplified propagation setup, with the measurements of diffuse gamma-rays. To better constrain the low-energy part of the model, we analyze the 14.6 years of Fermi-LAT data to extract the Galactic diffuse emission between 1 and 500 GeV from the same sky regions of LHAASO, after subtracting the contribution from known sources and the isotropic diffuse gamma-ray background. The joint Fermi-LAT and LHAASO spectra thus cover a very wide energy range from 1 GeV to 1 PeV with small gaps from 0.5 to 10 TeV. Compared with the prediction, we find that clear excesses between several GeV and ~60 TeV of the diffuse emission exist. Possible reasons to explain the excesses may include unresolved sources or more complicated propagation models. We illustrate that an exponential-cutoff-power-law component with an index of -2.40 and cutoff energy of ~30 TeV is able to account for such excesses