26 research outputs found
Self-adaptive online virtual network migration in network virtualization environments
This is the peer reviewed version of the following article: Zangiabady, M, GarciaâRobledo, A, Gorricho, JâL, SerratâFernandez, J, RubioâLoyola, J. Selfâadaptive online virtual network migration in network virtualization environments. Trans Emerging Tel Tech. 2019; 30:e3692. https://doi.org/10.1002/ett.3692, which has been published in final form at https://doi.org/10.1002/ett.3692. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.In Network Virtualization Environments, the capability of operators to allocate resources in the Substrate Network (SN) to support Virtual Networks (VNs) in an optimal manner is known as Virtual Network Embedding (VNE). In the same context, online VN migration is the process meant to reallocate components of a VN, or even an entire VN among elements of the SN in real time and seamlessly to end-users. Online VNE without VN migration may lead to either over- or under-utilization of the SN resources. However, VN migration is challenging due to its computational cost and the service disruption inherent to VN components reallocation. Online VN migration can reduce migration costs insofar it is triggered proactively, not reactively, at critical times, avoiding the negative effects of both under- and over-triggering. This paper presents a novel online cost-efficient mechanism that self-adaptively learns the exact moments when triggering VN migration is likely to be profitable in the long term. We propose a novel self-adaptive mechanism based on Reinforcement Learning that determines the right trigger online VN migration times, leading to the minimization of migration costs while simultaneously considering the online VNE acceptance ratio.Peer ReviewedPostprint (author's final draft
Seeking and Avoiding Choice Closure to Enhance Outcome Satisfaction
Consumers gain choice closure when they perceive a sense of finality over a past decision and limit comparisons between the selected and the forgone options. We investigate consumersâ ability to make strategic use of choice closure to enhance outcome satisfaction. Seven studies show that consumers experience greater satisfaction when they achieve choice closure with an inferior outcome and when they do not achieve choice closure with a superior outcome; however, they expect to be more satisfied by avoiding choice closure with an inferior outcome and by seeking it with a superior outcome. We provide a rationale for this experienceâexpectation contrast based on rule overgeneralization.
Consumers form their expectation on an implicit rule learned and internalized in a context in which it is appropriate and advantageous: when they aim to increase satisfaction with a future choice; however, consumers erroneously apply the same implicit rule to a different context, one in which they aim to increase satisfaction with a past choice. We conclude that consumers are unlikely to be able to make strategic use of choice closure to enhance satisfaction with the outcome of a decision they have made
Kokonaislukuoptimointiin perustuva koodigenerointi nÀkyvÀn datapolun arkkitehtuureille
As the use of embedded processors has spread throughout the society pervasively, the requirements for the processors have become much more diverse causing general purpose processors to be inefficient on many occasions. This creates the need for customized processors that are tailored for a particular use case. Transport triggered architecture is a processor architecture template that exploits the instruction level parallelism. The architecture provides the basic building blocks and means to construct custom tailored processors. Transport triggered architecture processors are statically scheduled, thus powerful instruction scheduling algorithms can bring up significant efficiency increases in terms of chip area, clock frequency, and energy consumption.
This thesis proposes an integer linear programming model for the instruction scheduling problem of the transport triggered architecture. The model describes the architecture characteristics, the particular processor resource constraints, and the operation dependencies of the scheduled program. It is possible to optimize the model for various criterion, for example to achieve as energy efficient processors as possible. This scheduling algorithm was implemented to the high-level language compiler of the TTA-based Co-design Environment, which is a toolset for designing processors using the transport triggered architecture template. The model was tested and measured with example problems such as complex number arithmetics, and vector dot product. Such example algorithms are typically executed in embedded processors and parallelize reasonably well. The performance results were compared to the existing heuristic graph-based scheduling algorithm of the toolset compiler.
The study indicates that the integer linear programming based instruction scheduler produced significantly shorter schedules compared to the heuristic scheduler. In addition, the amount of register access in the compiled programs was generally notably less than those of the heuristic scheduler. On the other hand, the proposed scheduler used distinctly more execution time than the heuristic scheduler
CTF3 BPM acquisition system
International audienc
Specification, Validation and Verification of Social, Legal, Ethical, Empathetic and Cultural Requirements for Autonomous Agents
Autonomous agents are increasingly being proposed for use in healthcare, assistive care, education, and other applications governed by complex human-centric norms. To ensure compliance with these norms, the rules they induce need to be unambiguously defined, checked for consistency, and used to verify the agent. In this paper, we introduce a framework for formal specification, validation and verification of social, legal, ethical, empathetic and cultural (SLEEC) rules for autonomous agents. Our framework comprises: (i) a language for specifying SLEEC rules and rule defeaters (that is, circumstances in which a rule does not apply or an alternative form of the rule is required); (ii) a formal semantics (defined in the process algebra tock-CSP) for the language; and (iii) methods for detecting conflicts and redundancy within a set of rules, and for verifying the compliance of an autonomous agent with such rules. We show the applicability of our framework for two autonomous agents from different domains: a firefighter UAV, and an assistive-dressing robot
Crustal Structure Across the Northern Region of the Islas Marias Archipelago
The tectonic interaction between the Rivera and North American plates north
of the Bahia de Banderas is poorly understood. The nature of the crust and
where the subduction ends in the western part of the Islas Marias Archipelago
are still controversial. Based on new geophysical data provided by the TsuJal
project, we present the shallow and deep crustal structure of the Rivera North
American plate contact zone along two seismic transects, TS09b and RTSIM01b,
and the bathymetry obtained across the northern region of Maria Madre Island.
Detailed bathymetric analysis allowed mapping of a series of lineaments along
the study region, with two main preferred tendencies (020 050 and 290 320)
associated with the evolution of the Pacific-Rivera rise and the transform
faults of the Gulf of California, respectively. The shallow structure is
characterized by five sedimentary basins without deformation, whose horizons
are subparallel, suggesting that the sediment deposition occurred after the
extension process ended. The deep structure corresponds to a transition between
oceanic crust (Rivera Plate), with an average thickness of 10 km to the Islas
Marias Escarpment, and a thinned continental crust, whose thickness increases
toward the continent until it reaches 28 km, with a dip angle of 7 10. The
absence of an accretionary prism suggests that the subduction process of the
Rivera Plate beneath the North American Plate to the north of Islas Marias has
ceased. In this study, we determined that the morphological expression of the
northern limit of the Rivera Plate corresponds to the Islas Marias Escarpment.Comment: Frontiers in Earth Science, 202
Prototyp-Radiatoren eines Barrel-DIRC fĂŒr das PANDA-Experiment
Das Antiprotonen-Experiment PANDA an der zukĂŒnftigen Beschleunigeranlage FAIR wird unter anderem Charmonium-ZustĂ€nde mit einer bis dato unerreichten Genauigkeit messen können. Um dieses Ziel zu erreichen, wird eine sehr gute TeilchenidentifikationsfĂ€higkeit verlangt. Eine gute Trennung zwischen Pionen und Kaonen wird durch den Einsatz eines Cherenkovdetektors erreicht. Die LeistungsfĂ€higkeit eines DIRC hĂ€ngt von dessen RadiatorgĂŒte ab. Um die QualitĂ€t der RadiatorstĂ€be spezifizieren zu können, wurde im Rahmen dieser Doktorarbeit eine optische Messapparatur entwickelt. Dieser Aufbau erlaubt es die Transmission sowie die OberflĂ€chenrauheit der StĂ€be zu messen. Es wurden mehrere RadiatorstĂ€be aus synthetischem Quarzglas und Acrylglas untersucht. Die Messgenauigkeit bei hochqualitativen StĂ€ben liegt fĂŒr die Transmissionsmessung bei etwa 1 Promille und fĂŒr die Rauheit bei 1-2 Angström. Die Messergebnisse bei verschiedenen WellenlĂ€ngen zeigen eine gute Ăbereinstimmung mit der skalaren Streutheorie, die den Zusammenhang zwischen Reflexionskoeffizienten und Rauheit beschreibt. Bei einer Strahlzeit an der GSI mit einem 2 GeV Protonenstrahl wurde ein erster Prototyp fĂŒr den Barrel-DIRC mit einem Stab aus synthetischem Quarzglas als Radiator getestet. Durch Variation des Einfallswinkels und der Position des Protonenstrahls auf dem Radiator konnten Cherenkovringe eindeutig nachgewiesen werden. Zudem wurde der Cherenkovwinkel und die Einzelphotonauflösung in guter Ăbereinstimmung mit dem Erwartetem und der Simulation bestimmt
The 2011 Eruption of the Recurrent Nova T Pyxidis; the Discovery, the Pre-eruption Rise, the Pre-eruption Orbital Period, and the Reason for the Long Delay
We report the discovery by M. Linnolt on JD 2455665.7931 (UT 2011 April
14.29) of the sixth eruption of the recurrent nova T Pyxidis. This discovery
was made just as the initial fast rise was starting, so with fast notification
and response by observers worldwide, the entire initial rise was covered (the
first for any nova), and with high time resolution in three filters. The speed
of the rise peaked at 9 mag/day, while the light curve is well fit over only
the first two days by a model with a uniformly expanding sphere. We also report
the discovery by R. Stubbings of a pre-eruption rise starting 18 days before
the eruption, peaking 1.1 mag brighter than its long-time average, and then
fading back towards quiescence 4 days before the eruption. This unique and
mysterious behavior is only the fourth known anticipatory rise closely spaced
before a nova eruption. We present 19 timings of photometric minima from 1986
to February 2011, where the orbital period is fast increasing with
P/dot{P}=313,000 yrs. From 2008-2011, T Pyx had a small change in this rate of
increase, so that the orbital period at the time of eruption was
0.07622950+-0.00000008 days. This strong and steady increase of the orbital
period can only come from mass transfer, for which we calculate a rate of
1.7-3.5x10^-7 Mo/yr. We report 6116 magnitudes between 1890 and 2011, for an
average B=15.59+-0.01 from 1967-2011, which allows for an eruption in 2011 if
the blue flux is nearly proportional to the accretion rate. The
ultraviolet-optical-infrared spectral energy distribution is well fit by a
power law with flux proportional to nu^1.0, although the narrow ultraviolet
region has a tilt with a fit of \nu^{1/3}. We prove that most of the T Pyx
light is not coming from a disk, or any superposition of blackbodies, but
rather is coming from some nonthermal source.Comment: ApJ submitted, 62 pages, 8 figures; much added data, updated analysi
Luminosity Measurement in the L3 Detector at LEP
One of the limiting factors in the determination of the electroweak parameters from cross section measurements of e+e- annihilation close to the Z pole is the precision of the luminosity measurement. The luminosity monitor of the L3 detector at LEP and the analysis of its data are described. Using a combination of a BGO calorimeter and a 3-layer silicon tracker, the absolute luminosity has been measured with an experimental precision of 0.08% in 1993 and 0.05% in 1994. The measurement relies on a detailed understanding of small-angle elastic e+e-(Bhabha) scattering from the experimental and theoretical point of view, as well as an excellent knowledge of the detector geometry
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The Extended Continental Crust West of Islas MarĂas (Mexico)
The crustal structure around the Islas MarĂas Archipelago has been debated for a long time. An important unresolved question is where the Rivera-North American plate subduction ends and the Tamayo fracture zone begins, from SE to NW. Results from the TsuJal project have shed light on the northwesternmost part of the Jalisco block structure. It is now clear that Sierra de Cleofas and the Islas MarĂas Escarpment comprise the northwestern continuation of the Middle America trench. However, other questions remain. In this paper, we present the structure of the shallow and deep crust and the upper mantle of the Islas MarĂas western region through the integration of multichannel seismic reflection, wide-angle seismic bathymetric and seismicity data, including records of an amphibious seismic network, OBS, and portable seismic stations, purposely deployed for this project, providing an onshore-offshore transect of 310 km length. Our findings disclose new evidence of the complex structure of the Rivera plate that dips 8°â9° underneath the NW Jalisco block as revealed by two seismic profiles parallel to the Islas MarĂas Escarpment. Moreover, we find five sedimentary basins and active normal faults at the edges of tectonic structures of the E-W oriented West Ranges and the N-S trending Sierra de Cleofas. Furthermore, the Sierra de Cleofas is the beginning of the active subduction of the Rivera plate beneath North America. The oceanic crust thickens and submerges towards the south while is coupled with the continental crust, from 6 km at the northern ends of the seismic profiles to 15 km in the contact region and 24 km at the coast and southern ends of them. The continental Moho was not fully characterized because of the geometry of the seismic transects, but a low-velocity layer associated with Rivera Plate subduction was observed beneath the Jalisco Block. Our results constrain the complexity of the area and reveal new structural features from the oceanic to continental crust and will be pivotal to assess geohazards in this area.</jats:p