The K-Th derivatives of the immanant and the X-symmetric power of an operator

In recent papers, formulas are obtained for directional derivatives, of all orders, of the determinant, the permanent, the m-th compound map and the m-th induced power map. This paper generalizes these results for immanants and for other symmetric powers of a matrix.

Optimal brake specific fuel consumption trajectory for stand-alone variable speed Diesel Gen-Set

Energy efficiency plays an important role to the CO2 emissions reduction, combating climate change and improving the competitiveness of the economy. The problem presented here is related to the use of stand-alone diesel gen-sets and its high specific fuel consumptions when operates at low loads. The variable speed gen-set concept is explained as an energy-saving solution to improve this system efficiency. This paper details how an optimum fuel consumption trajectory based on experimentally Diesel engine power map is obtained.

Étude de la réponse aiguë à l'exercice intermittent à haute intensité chez le patient coronarien

L'entraînement par intervalles à haute intensité est plus efficace que l'entraînement continu d’intensité modérée pour améliorer la consommation maximale d’oxygène (VO2max) et le profil métabolique des patients coronariens. Cependant, il n’y a pas de publications pour appuyer la prescription d’un type d’exercice intermittent (HIIE) spécifique dans cette population. Nous avons donc comparé les réponses aiguës cardio-pulmonaires de quatre sessions différentes d’exercice intermittent dans le but d’identifier l’exercice optimal chez les patients coronariens. De manière randomisée, les sujets participaient aux sessions d’HIIE, toutes avec des phases d’exercice à 100% de la puissance maximale aérobie (PMA), mais qui variaient selon la durée des phases d’exercice et de récupération (15s ou 1 min) et la nature de la récupération (0% de la PMA ou 50% de la PMA). Chaque session était réalisée sous forme de temps limite et l’exercice était interrompu après 35 minutes. En considérant l’effort perçu, le confort du patient et le temps passé au-dessus de 80% de VO2max, nous avons trouvé que l’exercice optimal consistait à alterner des courtes phases d’exercice de 15s à 100% de la PMA avec des phases de 15s de récupération passive. Ensuite, nous avons comparé les réponses physiologiques de l’HIIE optimisé avec un exercice continu d’intensité modérée (MICE) iso-calorique chez des patients coronariens. En considérant les réponses physiologiques, l’aspect sécuritaire (aucune élévation de Troponin T) et l’effort perçu, le protocole HIIE est apparu mieux toléré et plus efficace chez ces coronariens. Finalement, une simple session d’HIIE n’induit pas d’effets délétères sur la paroi vasculaire, comme démontré avec l’analyse des microparticules endothéliales. En conclusion, l’exercice intermittent à haute intensité est un mode d'entraînement prometteur pour les patients coronariens stables qui devrait faire l’objet d’autres études expérimentales en particulier pour les patients coronariens ischémiques.

Étude des réponses physiologiques aiguës à l’exercice intermittent de haute intensité chez le patient insuffisant cardiaque

L’optimisation de l’exercice par intervalles de haute intensité (EIHI) chez les patients insuffisants cardiaques (IC) n’a jamais été étudiée auparavant. Nous avons comparé les réponses cardio-pulmonaires aiguës lors de 4 différents EIHI dans le but de trouver le protocole optimisé chez les patients IC. Les patients IC étaient aléatoirement alloués à 4 sessions d’EIHI. Chaque phase d’exercice était à une intensité de 100% de la puissance aérobie maximale (PAM), mais de différentes durées (30s ou 90s) et de type de récupération (passive ou active). Chaque protocole d’EIHI durait un maximum de 30 minutes ou jusqu’à épuisement. Considérant le temps total d’exercice, l’adhérence, une perception d’effort moins élevée, le confort du patient ainsi que des temps similaires passés à un haut pourcentage du VO2pic, le mode avec intervalles courts (30s) et récupération passive s’est avéré être le protocole d’EIHI optimisé chez ces patients. Suite à cette étude, nous avons voulu comparer les réponses cardio-pulmonaires aiguës d’un exercice continu d’intensité modéré (ECIM) par rapport à celles de l’EIHI optimisé de dépense énergétique équivalente chez les patients IC. L’objectif de cette étude était de comparer les réponses cardio-pulmonaires, l’adhérence, la perception de l’effort, l’inflammation et les biomarqueurs cardiaques. Comparativement à l’ECIM, l’adhérence, l’efficience et la tolérance étaient plus élevées lors de l’EIHI optimisé chez les patients IC tout en produisant un stimulus physiologique important. L’EIHI n’a causé aucune arythmie significative ou d’effets délétères sur l’inflammation (CRP), le BNP et la nécrose myocardique (C-TnT) chez les patients IC. L’EIHI semble être un mode d’exercice prometteur et devrait être considéré lors de la réadaptation cardiaque chez les patients IC.

Simultaneous B(0)- and B(1)+-map acquisition for fast localized shim, frequency, and RF power determination in the heart at 3 T.

High-field (>or=3 T) cardiac MRI is challenged by inhomogeneities of both the static magnetic field (B(0)) and the transmit radiofrequency field (B(1)+). The inhomogeneous B fields not only demand improved shimming methods but also impede the correct determination of the zero-order terms, i.e., the local resonance frequency f(0) and the radiofrequency power to generate the intended local B(1)+ field. In this work, dual echo time B(0)-map and dual flip angle B(1)+-map acquisition methods are combined to acquire multislice B(0)- and B(1)+-maps simultaneously covering the entire heart in a single breath hold of 18 heartbeats. A previously proposed excitation pulse shape dependent slice profile correction is tested and applied to reduce systematic errors of the multislice B(1)+-map. Localized higher-order shim correction values including the zero-order terms for frequency f(0) and radiofrequency power can be determined based on the acquired B(0)- and B(1)+-maps. This method has been tested in 7 healthy adult human subjects at 3 T and improved the B(0) field homogeneity (standard deviation) from 60 Hz to 35 Hz and the average B(1)+ field from 77% to 100% of the desired B(1)+ field when compared to more commonly used preparation methods.

Ontario Hydro map of the St. Lawrence Power Project General Plan

Ontario Hydro map of the St. Lawrence Power Project General Plan, n.d.

Low dimensional behavior in three-dimensional coupled map lattices

The analysis of one-, two-, and three-dimensional coupled map lattices is here developed under a statistical and dynamical perspective. We show that the three-dimensional CML exhibits low dimensional behavior with long range correlation and the power spectrum follows 1/f noise. This approach leads to an integrated understanding of the most important properties of these universal models of spatiotemporal chaos. We perform a complete time series analysis of the model and investigate the dependence of the signal properties by change of dimension. (c) 2008 Elsevier Ltd. All rights reserved.

Spectral properties of chaotic signals generated by the skew tent map

Chaotic signals have been considered potentially attractive in many signal processing applications ranging from wideband communication systems to cryptography and watermarking. Besides, some devices as nonlinear adaptive filters and phase-locked loops can present chaotic behavior. In this paper, we derive analytical expressions for the autocorrelation sequence, power spectral density and essential bandwidth of chaotic signals generated by the skew tent map. From these results, we suggest possible applications in communication systems. (C) 2009 Elsevier B.V. All rights reserved.

Dynamic power- and failure-aware cloud resources allocation for Sets of independent tasks

Cloud computing is increasingly being adopted in different scenarios, like social networking, business applications, scientific experiments, etc. Relying in virtualization technology, the construction of these computing environments targets improvements in the infrastructure, such as power-efficiency and fulfillment of users’ SLA specifications. The methodology usually applied is packing all the virtual machines on the proper physical servers. However, failure occurrences in these networked computing systems can induce substantial negative impact on system performance, deviating the system from ours initial objectives. In this work, we propose adapted algorithms to dynamically map virtual machines to physical hosts, in order to improve cloud infrastructure power-efficiency, with low impact on users’ required performance. Our decision making algorithms leverage proactive fault-tolerance techniques to deal with systems failures, allied with virtual machine technology to share nodes resources in an accurately and controlled manner. The results indicate that our algorithms perform better targeting power-efficiency and SLA fulfillment, in face of cloud infrastructure failures.

Quantifying, generating and mitigating radio interference in Low-Power Wireless Networks

Doctoral Programme in Telecommunication - MAP-tele

Power transformations in correspondence analysis

Power transformations of positive data tables, prior to applying the correspondence analysis algorithm, are shown to open up a family of methods with direct connections to the analysis of log-ratios. Two variations of this idea are illustrated. The first approach is simply to power the original data and perform a correspondence analysis this method is shown to converge to unweighted log-ratio analysis as the power parameter tends to zero. The second approach is to apply the power transformation to thecontingency ratios, that is the values in the table relative to expected values based on the marginals this method converges to weighted log-ratio analysis, or the spectral map. Two applications are described: first, a matrix of population genetic data which is inherently two-dimensional, and second, a larger cross-tabulation with higher dimensionality, from a linguistic analysis of several books.

Self-organized criticality and synchronization in a coupled map lattice model of integrate-and-fire oscillators

We introduce two coupled map lattice models with nonconservative interactions and a continuous nonlinear driving. Depending on both the degree of conservation and the convexity of the driving we find different behaviors, ranging from self-organized criticality, in the sense that the distribution of events (avalanches) obeys a power law, to a macroscopic synchronization of the population of oscillators, with avalanches of the size of the system.

Development of power flows around Baltic countries with new grid links

In the Thesis main focus is done on power flow development paths around the Baltic States as well as on market-based requirements for creation of the common Baltic electricity market. Current market regulations between the countries are presented; barriers for creating competitive common Baltic power market and for electricity trading with third countries are clarified; solutions are offered and corresponding road map is developed. Future power development paths around the Baltic States are analysed. For this purpose the 330 kV transmission grid of Estonia, Latvia and Lithuania is modelled in a power flow tool. Power flow calculations are carried out for winter and summer peak and off-peak load periods in 2020 with different combinations of interconnections. While carrying out power balance experiments several power flow patterns in the Baltic States are revealed. Conclusions are made about security of supply, grid congestion and transmission capacity availability for different scenarios.

Clustering and diffusion in a symplectic map lattice with non-local coupling

We study a symplectic chain with a non-local form of coupling by means of a standard map lattice where the interaction strength decreases with the lattice distance as a power-law, in Such a way that one can pass continuously from a local (nearest-neighbor) to a global (mean-field) type of coupling. We investigate the formation of map clusters, or spatially coherent structures generated by the system dynamics. Such clusters are found to be related to stickiness of chaotic phase-space trajectories near periodic island remnants, and also to the behavior of the diffusion coefficient. An approximate two-dimensional map is derived to explain some of the features of this connection. (C) 2008 Elsevier Ltd. All rights reserved.

Wind Power Suitability Analysis for the Gulf of Maine

This map shows one option for a viable energy source that is clean, free and endless: wind power. This map shows that the coast of Maine has the potential space and wind speed to be a location for wind farms. Four NOAA buoys placed in different locations along the Maine coast are the source of the wind speed data for this project. The average wind speed of every ten minutes of every day for the year 2004 were averaged so that each buoy was represented by one number of wind speed measured in meters/ second. The values in between these four buoys were estimated, or interpolated, using ArcGIS. Other factors that I took into consideration during this lab were distance from airports (no wind farm can be with in a three mile radius of an airport ) and distance from counties (no one wants an offshore wind farm that obstructs their view). I calculated the most appropriate locations for a wind farm in ArcGIS, by adding these three layers. The final output shows an area along Mt. Desert to be the most appropriate for development.