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See detailDistintas variantes naturales del BLV presentan patrones diferenciales de unión a factores celulares
Rodriguez, Sabrina ULg; Varone, C.; Mozgovoj, M. et al

Poster (2003, December 01)

DISTINTAS VARIANTES NATURALES DEL BLV PRESENTAN PATRONES DIFERENCIALES DE UNIÓN A FACTORES CELULARES. S. Rodriguez1, C. Varone2, M. Mozgovoj1, C. Gómez1, M.J. DusSantos1, A. Wigdorovitz1, E. Cánepa2, K ... [more ▼]

DISTINTAS VARIANTES NATURALES DEL BLV PRESENTAN PATRONES DIFERENCIALES DE UNIÓN A FACTORES CELULARES. S. Rodriguez1, C. Varone2, M. Mozgovoj1, C. Gómez1, M.J. DusSantos1, A. Wigdorovitz1, E. Cánepa2, K. Trono1 1Instituto de Virología, CICVyA, INTA – Castelar. 2Cátedra de Biologia Molecular, Facultad de Ciencias Exactas, UBA. Buenos Aires, Argentina. La relación entre el genotipo y las formas de manifestación patogénica está demostrada para ciertos Retrovirus, y las zonas regulatorias Long Terminal Repeats (LTR) han sido descriptas, entre otros factores, como portadoras de determinantes de patogenia. En el caso del Virus de la Leucosis Bovina (VLB), estudios previos de secuencias llevados a cabo en nuestro laboratorio sobre las zona R-U5 de las regiones genéticas provirales LTR aisladas de 36 animales infectados naturalmente y con diferentes formas de evolución revelaron la presencia de 4 cambios fijos y característicos de provirus aislados de linfosarcoma (LS)(100%), 1 en la región R y 3 en U5. Estas modificaciones están ausentes en la mayoría (16/22) de los provirus aislados de formas asintomáticas (AL/PL). La alta asociación entre los cambios de nucleótidos y las formas de patogenia demostró la existencia de una secuencia de nucleótidos consenso y propia de los aislados de LS en la región U5 del LTR del genoma proviral de VLB. Con el objetivo de analizar si existe una capacidad diferencial de reconocimiento de factores de regulación de la transcripción celular en la célula hospedadora de las secuencias LTRs de aislamientos de distintas formas de patogenia, se utilizaron ensayos de cambio en la movilidad electroforética (EMSA). La evaluación conjunta de los resultados demuestra que existirían diferencias específicas de unión de la región U5 a proteínas del complejo de regulación de la transcripción celular denominadas E2F en relación con las diferentes presentaciones de esta patología. Estos hallazgos aportan datos en relación con la caracterización de esta co-variación de nucleótidos como marcadores de patogenia del VLB, así como también representan un adelanto en el conocimiento de la patobiología del BLV. [less ▲]

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See detailLes distorsions de ségrégation chez les plantes et leurs conséquences sur l'amélioration génétique
Diouf, F.B.H.; Mergeai, Guy ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(4), 499-508

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See detailThe Distorted Shape of Jupiter's North Auroral Oval - A Possible Magnetic Anomaly
Clarke, J. T.; Grodent, Denis ULg; Connerney, J.

Poster (2002)

Repeated imaging of Jupiter's aurora has shown that the northern main oval has a distorted "kidney bean" shape in the general range of 40-100 deg magnetic longitude, which appears unchanged since 1994 ... [more ▼]

Repeated imaging of Jupiter's aurora has shown that the northern main oval has a distorted "kidney bean" shape in the general range of 40-100 deg magnetic longitude, which appears unchanged since 1994. More recently, improved accuracy in locating the satellite footprint auroral emissions has provided new information about the geometry of Jupiter's magnetic field in this and other areas. The persistent pattern of the main oval implies a disturbance of the local magnetic field, and the increased latitudinal separation of the locus of satellite footprints from each other and from the main oval implies a locally weaker field strength. It is possible that these phenomena result from a magnetic anomaly in Jupiter's intrinsic magnetic field, as was proposed by A. Dessler in the 1970's. There is presently only limited evidence from the scarcity of auroral footprints observed in this longitude range. Similarly, while it is difficult to observe the conjugate regions in the southern aurora, there does not appear to be any corresponding distortion in the south. We will present the observational evidence that we have accumulated to date, propose future observations to determine the nature of this disturbance, and speculate on its causes and implications. [less ▲]

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See detailDistortion function and clustering for local linear models
Kerschen, Gaëtan ULg; Yan, Ai Min; Golinval, Jean-Claude ULg

in Journal of Sound & Vibration (2005), 280(1-2), 443-448

Principal component analysis (PCA) is a ubiquitous statistical technique for data analysis. PCA is however limited by its linearity and may sometimes be too simple for dealing with real-world data ... [more ▼]

Principal component analysis (PCA) is a ubiquitous statistical technique for data analysis. PCA is however limited by its linearity and may sometimes be too simple for dealing with real-world data especially when the relations among variables are nonlinear. Recent years have witnessed the emergence of nonlinear generalizations of PCA, as for instance nonlinear principal component analysis (NLPCA) [1] or vector quantization principal component analysis (VQPCA) [2]. VQPCA involves a two-step procedure, namely a clustering of the data space into several regions and the application of PCA in each local region. In Ref. [3], VQPCA was applied for the reconstruction of dynamical response and it was shown that it is potentially a more effective tool than conventional PCA. The purpose of this technical note is to further investigate VQPCA and to have a closer look at the choice of the distortion function used for clustering the data space. [less ▲]

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See detailDistortion-Invariant FOPEN Detection Filter Improvements
Casasent, David P.; Ippolito, K.; Verly, Jacques ULg

Conference (1999, April)

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See detailDistrait? Agité? Mon enfant présente-t-il un trouble déficitaire de l'attention avec/sans hyperactivité?
Catale, Corinne ULg

Conference given outside the academic context (2012)

La Clinique Psychologique et Logopédique Universitaire (CPLU) a le plaisir de vous inviter à sa prochaine conférence donnée par Corinne Catale (Docteur en Sciences Psychologiques) Le diagnostic du trouble ... [more ▼]

La Clinique Psychologique et Logopédique Universitaire (CPLU) a le plaisir de vous inviter à sa prochaine conférence donnée par Corinne Catale (Docteur en Sciences Psychologiques) Le diagnostic du trouble déficitaire de l'attention chez l'enfant reste encore très complexe. L'exposé aura comme premier objectif de décrire le fonctionnement cognitif des enfants atteints de ce trouble et ses conséquences sur la vie quotidienne. Ensuite, nous montrerons l'intérêt de la neuropsychologie dans son diagnostic, mais également dans sa prise en charge, avec la mise en place d'une remédiation cognitive personnalisée et focalisée sur les difficultés que l'enfant présente. [less ▲]

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See detailDistribución de tasas evolutivas en plantas vasculares entre el Silúrico y el Pleistoceno
Cascales - Miñana, Borja ULg; Ruiz-Sánchez, Francisco J.

in Cambra-Moo, O.; Martínez-Pérez, C.; Chamero, B. (Eds.) et al Cantera Paleontológica (2007)

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See detailDistribución geográfica y relaciones genéticas del género Arracacia Bancroft en el Perú
Blas Sevillano, R.; Arbizu, C.; Baudoin, Jean-Pierre ULg

Conference given outside the academic context (2004)

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See detailA distributed algorithm for weighted max-min fairness in MPLS networks
Skivée, Fabian ULg; Leduc, Guy ULg

in Lecture Notes in Computer Science (2004, August), 3124

We propose a novel distributed algorithm to achieve a weighted max-min sharing of the network capacity. We present the Weight Proportional Max-Min policy (WPMM) that supports a minimal rate requirement ... [more ▼]

We propose a novel distributed algorithm to achieve a weighted max-min sharing of the network capacity. We present the Weight Proportional Max-Min policy (WPMM) that supports a minimal rate requirement and an optional maximal rate constraint and allocates network bandwidth among all aggregates based on a weight associated with each one. Our algorithm achieves this policy for IP/MPLS networks using the RSVP-TE signalling protocol. It uses per-LSP accounting in each node to keep track of the state information of each LSP. It uses a novel explicit bottleneck link strategy and a different control architecture in which we update the control packet in the forward path. Simulations show that these two elements improve substantially the convergence time compared to algorithms designed for ATM networks. [less ▲]

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See detailDistributed Collaborative Design Studio : a sketch-based environment to support rich distant collaboration. Workshop.
Safin, Stéphane ULg; Delfosse, Vincent ULg; Elsen, Catherine ULg et al

Conference (2008)

An increasing number of large scale projects requires that distant teams collaborate together remotely. At the same time, the current CAD tools only offer minimal support for partial and asynchronous ... [more ▼]

An increasing number of large scale projects requires that distant teams collaborate together remotely. At the same time, the current CAD tools only offer minimal support for partial and asynchronous interactions. The application we propose enables full synchronous and remote sketch-based collaborative design. This setup is a combination of a virtual desktop (a remote meeting table), a standard videoconference system, a gesture recognition module and a networked, real-time, collaborative drawing software (SketSha). The solution as a whole is multimodal in essence (gestures, speech, drawing…) supporting immersive remote collaborative design. [less ▲]

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See detailDistributed control of electromechanical oscillations in very large-scale electric power systems
Wang, Da ULg

Doctoral thesis (2014)

Electromechanical oscillations threaten the secure operation of power systems and if not controlled efficiently can lead to generator outages, line tripping and even large-scale blackouts. Different ... [more ▼]

Electromechanical oscillations threaten the secure operation of power systems and if not controlled efficiently can lead to generator outages, line tripping and even large-scale blackouts. Different damping devices, like Power System Stabilizers (PSSs), Thyristor Controlled Series Compensators (TCSCs), and so on, are installed to damp these oscillations. This thesis proposes a trajectory-based supplementary control to improve damping effects of existing controllers, which treats damping control as a multi-step optimization control problem with discrete dynamics and costs. At each control time, it collects current system states, solves the optimal control problem and superimposes the calculated supplementary inputs on the outputs of existing damping controllers, in order to enhance the damping. These supplementary signals are continuously updated, which allows to adaptively adjust and coordinate a subset of existing damping controllers, and eventually all of them. Two kinds of methods, Model Predictive Control (MPC) and Reinforcement Learning (RL), are used to embody the proposed supplementary damping control. Firstly, a fully centralized MPC scheme is designed based on a linearized, discrete, complete state space model. Its performances are evaluated both in ideal conditions and considering realistic state estimation errors, and computation and communication delays. The effects of the number and type of available damping controllers are also studied. This scheme is further extended into a distributed scheme with the aim of making it more viable for very large-scale or multi-area systems. Different ways of decoupling and coordinating between subsystems are analyzed. Finally, a robust hierarchical multi-area MPC scheme is proposed, introducing a second layer of MPC based controllers at the level of individual power plants and transmission lines. Secondly, a tree-based batch mode RL algorithm is applied to carry on the proposed supplementary damping control. Using a set of dynamic and reward four-tuples, it constructs an approximation of the optimal $Q$-function over a given temporal horizon. The actions greediest with respect to the $Q$-function are applied as supplementary signals to existing damping controllers. The scheme is firstly tested on a single generator, and then on multiple generators. Different reward signals and damping levels are also considered. Finally, the combined control effects of MPC and RL are investigated. [less ▲]

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See detailDistributed Dynamic Load Balancing for Iterative-Stencil Applications
Dethier, Gérard ULg; Marchot, Pierre ULg; de Marneffe, Pierre-Arnoul ULg

in Cracow Grid Workshop '08 Proceedings (2009, March)

In the context of jobs executed on heterogeneous clusters or Grids, load balancing is essential. Indeed, a slow machine must receive less work than a faster one otherwise the overall job termination will ... [more ▼]

In the context of jobs executed on heterogeneous clusters or Grids, load balancing is essential. Indeed, a slow machine must receive less work than a faster one otherwise the overall job termination will be delayed. This is particularly true for Iterative-Stencil Applications where tasks are run simultaneously and are interdependent. The problem of assigning coexisting tasks to machines is called mapping. With dynamic clusters (where the number of machines and their available power can change over time), dynamic mapping must be used. A new mapping must be calculated each time the cluster changes. The mapping calculation must therefore be fast. Also, a new mapping should be as close as possible to the previous mapping in order to minimize task migrations. Dynamic mapping methods exist but are based on iterative optimization algorithms. Many iterations are required to reach convergence. In the context of a distributed implementation, many communications are needed. We developed a new distributed dynamic mapping method which is not based on iterative optimization algorithms. Current results are encouraging. Load balancing execution time remains bounded for tested cluster sizes. Also, a decrease of ~20% of the global available computational power of a cluster leads to ~30% of migrated tasks during load rebalancing. A new mapping is therefore close to the previous one. [less ▲]

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See detailDistributed fiber-optic temperature sensing for hydrologic systems
Selker, John S.; Thévenaz, Luc; Huwald, Hendrik et al

in Water Resources Research (2006), 42(12), 12202

Instruments for distributed fiber-optic measurement of temperature are now available with temperature resolution of 0.01°C and spatial resolution of 1 m with temporal resolution of fractions of a minute ... [more ▼]

Instruments for distributed fiber-optic measurement of temperature are now available with temperature resolution of 0.01°C and spatial resolution of 1 m with temporal resolution of fractions of a minute along standard fiber-optic cables used for communication with lengths of up to 30,000 m. We discuss the spectrum of fiber-optic tools that may be employed to make these measurements, illuminating the potential and limitations of these methods in hydrologic science. There are trade-offs between precision in temperature, temporal resolution and spatial resolution, following the square root of the number of measurements made; thus brief, short measurements are less precise than measurements taken over longer spans in time and space. Five illustrative applications demonstrate configurations where the distributed temperature sensing (DTS) approach could be used: (1) lake bottom temperatures using existing communication cables, (2) temperature profile with depth in a 1400 m deep decommissioned mine shaft, (3) air-snow interface temperature profile above a snow-covered glacier (4) air-water interfacial temperature in a lake, and (5) temperature distribution along a first-order stream. In examples 3 and 4 it is shown that by winding the fiber around a cylinder, vertical spatial resolution of millimeters can be achieved. These tools may be of exceptional utility in observing a broad range of hydrologic processes including evaporation, infiltration, limnology, and the local and overall energy budget spanning scales from 0.003 to 30,000 m. This range of scales corresponds well with many of the areas of greatest opportunity for discovery in hydrologic science. [less ▲]

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See detailDistributed GIS for sharing large scale data between public agencies. A case study in Belgium
Donnay, Jean-Paul ULg

in GIS 2002 International Conference Proceedings (2002)

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See detailA Distributed Implementation of Fast Fourier Transforms
Verly, Jacques ULg; Kirk, Donald E.

Conference (1984, November)

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See detailA Distributed Lattice Boltzmann-based Flow Simulator
Dethier, Gérard ULg

Conference (2009, January 22)

The use of Lattice Boltzmann (LB) methods is interesting to describe flows through complex geometries encountered in Chemical Engineering (porous media, packed beds, multi phase flows). However, flow ... [more ▼]

The use of Lattice Boltzmann (LB) methods is interesting to describe flows through complex geometries encountered in Chemical Engineering (porous media, packed beds, multi phase flows). However, flow simulations based on LB methods can require big amounts of memory. It is not always possible to run a simulation on a single machine. Distributed computing is a solution to this problem and also accelerates the execution of the flow simulation. In the context of dynamic heterogeneous clusters, the available machines can have different computational powers. The computational power of each machine can vary during a flow simulation (because of background load). Also, the number of available machines can change. These characteristics impose the use of special technics. Dynamic Load Balancing allows the optimal use of available machines. A fault occurs when one or several machines interrupt the execution of the distributed software component they were executing. Checkpointing makes the system fault tolerant. In order to obtain a scalable software and to suppress single points of failure, a special effort is made to decentralize as much as possible the software components of the simulator. Currently, fluid flows of 400³ points (more than 9 GBytes of data) are simulated using an heterogeneous cluster of 54 machines. [less ▲]

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See detailDistributed load interruption and shedding against voltage delayed recovery or instability
Otomega, Bogdan; Van Cutsem, Thierry ULg

in Proc. IEEE PES 2013 PowerTech Conference (2013, June)

This paper deals with a two-part system integrity protection scheme to be installed in distribution networks, to counteract fault-induced delayed voltage recovery or even short-term voltage instability ... [more ▼]

This paper deals with a two-part system integrity protection scheme to be installed in distribution networks, to counteract fault-induced delayed voltage recovery or even short-term voltage instability due to induction motors. The first part consists of a fast triggered but temporary reduction of some loads to facilitate motor re-acceleration after fault clearing. The second part resorts to load shedding, as a back-up. The scheme relies on purely distributed controllers; each of them measures a bus voltage and interrupts/disconnects load at the same bus. Tests have been performed on a generic MV/LV system. They illustrate the benefit of load interruption and the selectivity of the proposed scheme. [less ▲]

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See detailDistributed Model-free Control of Photovoltaic Units for Mitigating Overvoltages in Low-Voltage Networks
Aristidou, Petros ULg; Olivier, Frédéric ULg; Hervas, Maria Emilia et al

in Proc. of CIRED 2014 workshop (2014, June)

In this paper, a distributed model-free control scheme to mitigate overvoltage problems caused by high photovoltaic generation in low-voltage feeders is proposed. The distributed controllers are ... [more ▼]

In this paper, a distributed model-free control scheme to mitigate overvoltage problems caused by high photovoltaic generation in low-voltage feeders is proposed. The distributed controllers are implemented on the photovoltaic inverters and modulate the active and reactive power injected into the network. In particular, they direct photovoltaic units first to consume reactive power and, if necessary, curtail active power generation to reduce high voltages in the feeder. [less ▲]

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See detailDistributed MPC of wide-area electromechanical oscillations of large-scale power systems
Wang, Da ULg; Glavic, Mevludin; Wehenkel, Louis ULg

in Proceedings of ISAP 2011 (2011, September)

We investigate distributed Model Predictive Control (MPC) to damp wide-area electromechanical oscillations. Our distributed MPC schemes are derived from and compared with a fully centralized MPC scheme ... [more ▼]

We investigate distributed Model Predictive Control (MPC) to damp wide-area electromechanical oscillations. Our distributed MPC schemes are derived from and compared with a fully centralized MPC scheme proposed in a previous publication. Based on simulations carried out using a 16-generator, 70-bus, two-area test power system, we show that simple coordination schemes based on additional local measurements’ feedback yield already a significant improvement with respect to a scheme with only implicit coordination, improve significantly with respect to purely local controls, and in this respect reach about 75% of the improvements obtained by an ideal centralized MPC scheme. [less ▲]

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See detailA Distributed Signal Processing Architecture
Filip, A. E.; Arthur, James S.; Drinan, John D. et al

Report (1983)

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