173,690 research outputs found
Resilient Cloud Network Mapping with Virtualized BBU Placement for Cloud-RAN
No full textCloud Radio Access Network (C-RAN) will improve mobile radio coordination and resource efficiency by allowing baseband processing unit (BBU) functions to be virtualized and centralized, i.e., deployed in a BBU hotel. We consider a BBU hoteling scheme based on the concept of access cloud network (ACN). An ACN consists of virtualized BBUs (vBBUs) placed in metro cloud data centers (metro DCs). A vBBU is connected to a set of remote radio heads (RRHs). ACN resiliency against network and processing failures is critical for C-RAN deployments. Hence, in this study, we propose three protection approaches: 1+1 ACN protection, 1+1 ACN and vBBU protection, and partial ACN protection. Simulation results show that both 1+1 ACN and 1+1 ACN and vBBU protection requires large capacity for backup to provide 100% survivability for singlelink and single-DC failures. As a result, we suggest a partial ACN protection approach which provides degraded services with only 8% additional network resources.</p
Recurrence coefficients for discrete orthonormal polynomials and the Painlevé equations
No full textWe investigate semi-classical generalizations of the Charlier and Meixner polynomials, which are discrete orthogonal polynomials that satisfy three-term recurrence relations. It is shown that the coefficients in these recurrence relations can be expressed in terms of Wronskians of modified Bessel functions and confluent hypergeometric functions, respectively for the generalized Charlier and generalized Meixner polynomials. These Wronskians arise in the description of special function solutions of the third and fifth Painlevé equations
Load balancing and latency reduction in multi-user CoMP over TWDM-VPONs
No full textIn emerging cellular systems, optical fronthaul is expected to play a major role to support many control operations, e.g., Coordinated Multipoint (CoMP). CoMP is a promising technique for interference mitigation as it can transform interfing signals into joint transmission (reception) in which signals from adjacent cell sites are simultaneously transmitted (received) to (from) mobile terminals. But the exchange of information required by CoMP demands high flexibility and capacity. This paper proposes a new architecture for supporting CoMP operations in emerging cellular systems. It is based on a time-and-wavelength-division-multiplexed passive optical network (TWDM-PON) fronthaul, using virtualized base stations and a cloud radio access network (C-RAN) architecture. We also propose techniques to distribute the load on controllers to minimize the coordination delay. Results show that, for a typical setting, our methods can save up to 37% on the time required to distribute channel state information among multiple base stations
Disaster-Survivable Cloud-Network Mapping
No full textCloud-computing services are provided to consumers through a network of servers and network equipment. Cloud-network (CN) providers virtualize resources [ e. g., virtual machine (VM) and virtual network (VN)] for efficient and secure resource allocation. Disasters are one of the worst threats for CNs as they can cause massive disruptions and CN disconnection. A disaster may also induce post-disaster correlated, cascading failures which can disconnect more CNs. Survivable virtual-network embedding (SVNE) approaches have been studied to protect VNs against single physical-link/-node and dual physical-link failures in communication infrastructure, but massive disruptions due to a disaster and their consequences can make SVNE approaches insufficient to guarantee cloud-computing survivability. In this work, we study the problem of survivable CN mapping from disaster. We consider risk assessment, VM backup location, and post-disaster survivability to reduce the risk of failure and probability of CN disconnection and the penalty paid by operators due to loss of capacity. We formulate the proposed approach as an integer linear program and study two scenarios: a natural disaster, e. g., earthquake and a human-made disaster, e. g., weapons-of-mass-destruction attack. Our illustrative examples show that our approach reduces the risk of CN disconnection and penalty up to 90% compared with a baseline CN mapping approach and increases the CN survivability up to 100% in both scenarios
From appraisal and attention to affective experience : genetic, social and exercise-based influences on emotional evaluation and psychophysiological reactions
No full textExperiencing an affective, emotional state upon encountering novel stimuli is dependent on the nature of the stimulus as well as the appraisal of the stimulus by the perceiving individual. Contemporary views on stimulus processing consider appraisal to be the underlying mechanism determining the subjective affective outcome, as it is experienced by the individual. This thesis had the objective of contributing to the understanding of appraisal processes in healthy participants, with a special focus on self- versus other-reference of the experienced stimuli. To this extent, the experimental His-Mine paradigm (Herbert, DFG HE5880/3-1) has been repeatedly employed, assessing the emotional evaluation of positive, negative, and neutral words, combined with self- or other-reference.
In the first study, associations between genetic markers (OXTR polymorphisms rs53576 and rs2268498) and emotional evaluation have been investigated, demonstrating a possible relationship in the form of an interpretation bias in the appraisal of neutral words, i.e., ambiguous stimuli devoid of valence information (Meixner, Montag, & Herbert, 2019). While the usually found self-positivity bias did not interact with participants’ genotype, rs53576-A+/rs2268498-C+ carriers displayed a less positive, and more negative interpretation bias in the appraisal of neutral stimuli, depending on self- or other-reference of the stimuli.
In the second study, romantic relationships have been examined as a possible factor changing the appraisal of self- and other-related emotional information, even in the absence of explicit partner-related instructions. It could be shown that the self-positivity bias persisted in a romantic relationship. However, participants in a romantic relationship evaluated positive, other-related stimuli more often in a valence-congruent fashion, and therefore akin to positive, self-related stimuli (Meixner & Herbert, 2018).
In the third study, the influence of acute aerobic exercise with varying attentional focus on the evaluation of self- and other-related emotional stimuli has been tested. Results suggested that while aerobic exercise is an affective experience influencing mood and subjective exertion, this did not transfer into subsequent emotional evaluation, ruling out effects of mood-congruent
processing. However, it could be shown that the attentional focus instruction led to slower reaction times in the subsequent emotional evaluation paradigm compared to the exercise condition without attentional focus instruction, possibly caused by the increased demands of the additional attention task. The direction of the self-reported attentional focus during exercise proved to be related to the self-positivity bias in subsequent emotional evaluation: An internal focus of attention on bodily stimuli during the aerobic exercise was associated with a larger difference between the number of valence-congruent answers in positive, self-related compared to positive, other-related words, and vice versa for an external focus of attention (Meixner & Herbert, 2022).
Lastly, in the fourth study, the psychophysiological effects of acute aerobic exercise with different attentional focus have been examined. It could be shown that instructed attentional focus did not influence affective experience of exercise, perceived exertion, or physiological parameters, such as heart rate variability (HRV), and pre-ejection period (PEP). Follow-up analyses, however, hinted at a possible relationship between self-reported attentional focus and psychophysiological parameters (Meixner & Herbert, 2021).
Taken together, the presented studies and their results illustrate associations of factors which differ on their time scale, on stimulus appraisal and affective experiences: Stable factors, such as genetics, long-term factors such as romantic relationships and short-term influences, such as acute aerobic exercise with varying attentional focus on stimulus appraisal have been
investigated. In sum, these findings contribute to uncovering the relationship of biopsychological influences, emotional evaluation, and affective experiences in the appraisal process of verbal and bodily stimuli.Affektives, emotionales Erleben als Reaktion auf neuartige Reize wird beeinflusst von den
Eigenschaften des Reizes, aber auch von der Bewertung der wahrnehmenden Person. Aktuelle
Theorien zur Reizverarbeitung nennen die Bewertung eines Reizes als essenzielle Komponente,
die dem subjektiven affektiven Erleben eines Individuums zugrunde liegt. Diese Dissertation
wurde mit dem Ziel angefertigt, das Verständnis dieser Bewertungsprozesse in gesunden
Stichproben zu verbessern, mit speziellem Augenmerk auf den Selbst- oder Fremdbezug der
erlebten Reize. Dabei wurde das experimentelle His-Mine Paradigma (Herbert, DFG
HE5880/3-1) mehrfach verwendet, mit dem die emotionale Evaluation positiver, negativer und
neutraler Worte, gekoppelt mit Selbst- oder Fremdbezug erfasst werden kann.
In der ersten Studie wurden Zusammenhänge zwischen genetischen Markern (OXTR
Polymorphismus rs53576 und rs2268498) und emotionaler Evaluation untersucht. Die
Ergebnisse stützen einen möglichen Zusammenhang in Form eines Interpretationsbias bei der
Bewertung neutraler Worte, also ambiger Reize, die keine Valenzinformationen beinhalten
(Meixner, Montag, & Herbert, 2019). Der übliche Befund eines Self-Positivity Bias war
unabhängig vom Genotyp der Teilnehmenden nachzuweisen. Träger der rs53576-
A+/rs2268498-C+ Allele zeigten jedoch einen weniger positiven, eher negativen
Interpretationsbias in der Bewertung neutraler Reize, in Abhängigkeit von deren Selbst- und
Fremdbezug.
In der zweiten Studie wurden romantische Beziehungen als ein möglicher Einflussfaktor
untersucht, der die Bewertung von selbst- und fremdbezogenen Reizen verändern könnte. Es
wurde geprüft, ob sich dies sogar in Abwesenheit von expliziten, partnerbezogenen
Instruktionen zeigen lässt. Die Ergebnisse zeigten, dass der Self-Positivity Bias in einer
romantischen Beziehung insgesamt erhalten bleibt, aber Teilnehmende in einer romantischen
Beziehung positive, fremdbezogene Stimuli häufiger als valenzkongruent, und somit
vergleichbar zu positiven, selbstbezogenen Stimuli bewerten (Meixner & Herbert, 2018).
In der dritten Studie wurde der Einfluss von akuter sportlicher Aktivität im aeroben Bereich mit
verschiedenem Aufmerksamkeitsfokus auf die Evaluation selbst- und fremdbezogener
emotionaler Reize erforscht. Aerobe sportliche Aktivität erwies sich als eine affektive
Erfahrung und beeinflusste Stimmung sowie die subjektive Anstrengung. Diese Effekte
übertrugen sich jedoch nicht auf die Evaluation emotionaler Reize, was einer
stimmungskongruenten Verarbeitung im verwendeten experimentellen His-Mine Paradigma widerspricht. Es konnte jedoch gezeigt werden, dass eine Instruktion zur
Aufmerksamkeitsfokussierung zu langsameren Reaktionszeiten im nachfolgenden
Evaluationsparadigma führte, was auf die erhöhten Anforderungen durch die parallele
Aufmerksamkeitsfokussierung zurückzuführen sein könnte. Die selbstberichtete Richtung der
Aufmerksamkeit zeigte einen Zusammenhang mit dem Self-Positivity Bias in der emotionalen
Evaluationsaufgabe: Je stärker Teilnehmende ihre Aufmerksamkeit auf internale Reize während
der sportlichen Aktivität fokussierten, desto größer war die Differenz zwischen
valenzkongruenten Antworten auf positive, selbstbezogene Worte und positive, fremdbezogene
Worte. Je ausgeprägter Teilnehmende external fokussierten, desto geringer war diese Differenz
(Meixner & Herbert, 2022).
Zuletzt wurden in der vierten Studie zusätzlich die psychophysiologischen Effekte von
sportlicher Aktivität mit verschiedenem Aufmerksamkeitsfokus untersucht. Es konnten hierbei
keine Zusammenhänge von affektivem Erleben sportlicher Aktivität, der subjektiven
Anstrengung und physiologischen Parametern, wie der Herzratenvariabilität (HRV) und der
Präejektionsperiode (PEP), und dem instruierten Aufmerksamkeitsfokus während der Aktivität
gezeigt werden. Sekundäre Analysen deuteten jedoch auf einen möglichen Zusammenhang
zwischen selbstberichtetem Aufmerksamkeitsfokus und psychophysiologischen Parametern hin
(Meixner & Herbert, 2021).
Zusammengefasst beleuchten die dargestellten Studien und Ergebnisse die Beziehungen
diverser Einflussfaktoren der emotionalen Evaluation von Reizen und affektivem Erleben
verschiedener zeitlicher Ausdehnung: Zeitstabile genetische Faktoren, Langzeitfaktoren, wie
romantische Beziehungen, sowie kurzzeitige Einflüsse, wie akute sportliche Aktivität, wurden
erforscht. Die berichteten Befunde leisten einen Beitrag, unser Verständnis der
Zusammenhänge zwischen biopsychologischen Einflüssen, emotionaler Evaluation und
affektivem Erleben in den Bewertungsprozessen von verbalen und körperlichen Reizen zu
verbessern
Disaster-resilient virtual-network mapping and adaptation in optical networks
No full textToday's Internet applications include grid- and cloud-computing services which can be implemented by mapping virtual networks (VNs) over physical infrastructure such as an optical network. VN mapping is a resource-allocation problem where fractions of the resources (e.g., bandwidth and processing) in the physical infrastructure (e.g., optical network and servers/data-centers) are provisioned for specific applications. Researchers have been studying the survivable VN mapping (SVNM) problem against physical-infrastructure failures (typically by deterministic failure models), because this type of failure may disconnect one or more VNs, and/or reduce their capacities. However, disasters can cause multiple link/node failures which may disconnect many VNs and dramatically increase the post-disaster vulnerability to correlated cascading failures. Hence, we investigate the disaster-resilient and post-disaster- survivable VN mapping problem using a probabilistic model to reduce the expected VN disconnections and capacity loss, while providing an adaptation to minimize VN disconnections by any postdisaster single-physical-link failure. We model the problem as an integer linear program (ILP). Numerical examples show that our approach reduces VN disconnections and the expected capacity loss after a disaster.</p
Manhattan 1926
No full textPictorial map. Bird's-eye view. Oriented with north to the upper right. Title within illustrative cartouche. Map within illustrative border. Inset: The continuation of the map of Manhattan showing the northern part, 1926.Color"The is all askew.
Meervoudige Charlier en Meixner veeltermen
No full textWe investigate multiple Charlier and multiple Meixner polynomials. These are extensions of the classical Charlier and Meixner polynomials which are orthogonal polynomials with respect to the Poisson distribution and the Pascal distribution (negative binomial distribution). For multiple C harlier polynomials we impose orthogonality conditions with respect to&n bsp;r different Poisson distributions (with r > 1) and for multiple Meixner polynomials we use r different Pasc al distributions. Depending on the choice of which parameters we select, we then get multiple Meixner polynomials of the first or of the second kind. We give a generating function for multiple Charlier polynomials an d we explicitly compute the recurrence coefficients for the recurrence r elations connecting the nearest neighbor multiple Charlier polynomials. The most important result is the asymptotic behavior of the ratio of two neighboring multiple Charlier polynomials and the asymptotic behavior o f the distribution of the (scaled) zeros, which turn out to be uniformly distributed, independent of the choice of the parameters of the Poisson distributions. We also investigate the case where one of the parameters depends on the scaling and then find a combination of a uniform distrib ution and a new distribution, which in some cases lives on an interval d isjoint of the interval where the scaled zeros are uniformly distributed . We also give a generating function for multiple Meixner polynomials of the first and of the second kind and we compute the coefficients in the nearest neighbor recurrence relations explicitly. Using these formulas, we are able to build on recent results of Miki, Tsujimoto, Vinet and Zh edanov who introduced non-Hermitian oscillator Hamiltonians for which th e eigenstates can be expressed in terms of multiple Charlier polynomials or multiple Meixner polynomials of the first kind. We extend this by co nstructing non-Hermitian oscillator Hamiltonians for which the eigenstat es can be described in terms of multiple Meixner polynomials of the seco nd kind (for r = 2).status: Publishe
Modèles Combinatoires pour les Polynômes de Meixner
No full textNous décrivons trois modèles combinatoires pour les polynômes de Meixner mn(x: β, c), à savoir les endofonctions de Meixner, les permutations bicolorées et les permutations partiellement soulignées. Ce dernier modèle a été introduit par Kreweras, qui a étudié le cas particulier des polynômes mn (x; 1, 1/2)
Meixner-like functions having a rational z-transform
No full textSquare-summable causal functions can be expressed in a Meixner series. In principle, approximate filter synthesis is thus possible. However, Meixner filters are not realizable since the Meixner functions do not have a rational z-transform. A set of orthonormal functions is constructed with the following properties. Like the Meixner functions, these functions are a generalization of the discrete Laguerre functions and they have a polynomial character as well. In contrast with the Meixner functions, they have the desired property of a rational z-transform
- …
