Filters








10,722 Hits in 2.8 sec

Carta de 23 de abril de Matthias Langhoff a Nicolas Royer, diretor do Espace des Arts, Scène nationale, Chalon-sur-Saône

Matthias Langhoff, Nicolas Royer
2020 Sala Preta  
Carta de 23 de abril de Matthias Langhoff a Nicolas Royer, diretor do Espaço das Artes, Cena Nacional, Chalon-sur-Saône  ...  Carta de 23 de abril de Matthias Langhoff a Nicolas Royer que não têm padaria.  ...  Carta de 23 de abril de Matthias Langhoff a Nicolas Royer Comentário de uma carta Quando reli minha carta a Nicolas Royer, tive um antigo sentimento de impotência que me é familiar.  ... 
doi:10.11606/issn.2238-3867.v20i1p55-68 fatcat:h6ebb2kctfcr7b3hosotz34bem

Unifying Parsimonious Tree Reconciliation [article]

Nicolas Wieseke, Matthias Bernt, Martin Middendorf
2013 arXiv   pre-print
Evolution is a process that is influenced by various environmental factors, e.g. the interactions between different species, genes, and biogeographical properties. Hence, it is interesting to study the combined evolutionary history of multiple species, their genes, and the environment they live in. A common approach to address this research problem is to describe each individual evolution as a phylogenetic tree and construct a tree reconciliation which is parsimonious with respect to a given
more » ... nt model. Unfortunately, most of the previous approaches are designed only either for host-parasite systems, for gene tree/species tree reconciliation, or biogeography. Hence, a method is desirable, which addresses the general problem of mapping phylogenetic trees and covering all varieties of coevolving systems, including e.g., predator-prey and symbiotic relationships. To overcome this gap, we introduce a generalized cophylogenetic event model considering the combinatorial complete set of local coevolutionary events. We give a dynamic programming based heuristic for solving the maximum parsimony reconciliation problem in time O(n^2), for two phylogenies each with at most n leaves. Furthermore, we present an exact branch-and-bound algorithm which uses the results from the dynamic programming heuristic for discarding partial reconciliations. The approach has been implemented as a Java application which is freely available from http://pacosy.informatik.uni-leipzig.de/coresym.
arXiv:1307.7831v1 fatcat:e2yrtfm77rguzekvn4y6rjzcfe

Biased contests

Matthias Dahm, Nicolás Porteiro
2008 Public Choice  
We examine the e¤ects of providing more accurate information to a political decisionmaker who is lobbied by competing interests. Conventional wisdom holds that such a bias in the direction of the correct decision improves the e¢ ciency of government. We provide a formal de...nition of bias which is derived from the same fundamentals that give rise to a contest model of lobbying. E¢ ciency of government is measured by both the probability of taking the correct decision and the amount of social
more » ... ste associated to lobbying activities. We present a benchmark model in which increasing the bias always improves the e¢ ciency of government under both criteria. However, this result is fragile in the sense that reasonable alternative assumptions in the micro-foundations lead to slightly di¤erent models in which -due to di¤erent strategic e¤ects of bias -under either criterion there is no guarantee that more accurate information improves government.
doi:10.1007/s11127-008-9278-x fatcat:5ouvpnhx2fc7zhfqfpstz3bwzu

Increasing the Expressiveness of Analytical Performance Models for Replicated Databases [chapter]

Matthias Nicola, Matthias Jarke
1999 Lecture Notes in Computer Science  
The vast number of design options in replicated databases requires efficient analytical performance evaluations so that the considerable overhead of simulations or measurements can be focused on a few promising options. A review of existing analytical models in terms of their modeling assumptions, replication schemata considered, and network properties captured, shows that data replication and intersite communication as well as workload patterns should be modeled more accurately. Based on this
more » ... nalysis, we define a new modeling approach named 2RC (2-dimensional replication model with integrated communication). We derive a complete analytical queueing model for 2RC and demonstrate that it is of higher expressiveness than existing models. 2RC also yields a novel bottleneck analysis and permits to evaluate the trade-off between throughput and availability. Introduction Replication management in distributed databases concerns the decision when and where to allocate physical copies of logical data fragments (replica placement), and when and how to update them to maintain an acceptable degree of mutual consistency (replica control). Replication intends to increase data availability in the presence of site or communication failures, and to decrease retrieval costs by local access if possible. The maintenance of replicated data is therefore closely related to intersite communication, and replication management has significant impact on the overall system performance. The literature offers several algorithms for replica placement [32, 22] as well as for replica control [8, 9, 15] . However, the sophistication of such methods is not matched by today's analytical models for performance evaluation. Considering the vast number of alternatives in the design of a replication schema, it becomes apparent that existing analytical models only consider very extreme replication schemata, e.g. no replication or full replication. Furthermore, the important role of intersite communication in replica management is not sufficiently taken into account. While the evolution and symbiosis of distributed database and modern communication systems is progressing, theoretical performance models to evaluate such systems lag behind. Our aim is to identify and remedy such flaws in the performance evaluations
doi:10.1007/3-540-49257-7_10 fatcat:wsqlcyzefjcppjfiohdg66vdee

NMR Quantum Information Processing [article]

Chandrasekhar Ramanathan, Nicolas Boulant, Zhiying Chen, David G. Cory, Isaac Chuang, Matthias Steffen
2004 arXiv   pre-print
Nuclear Magnetic Resonance (NMR) has provided a valuable experimental testbed for quantum information processing (QIP). Here, we briefly review the use of nuclear spins as qubits, and discuss the current status of NMR-QIP. Advances in the techniques available for control are described along with the various implementations of quantum algorithms and quantum simulations that have been performed using NMR. The recent application of NMR control techniques to other quantum computing systems are
more » ... wed before concluding with a description of the efforts currently underway to transition to solid state NMR systems that hold promise for scalable architectures.
arXiv:quant-ph/0408166v1 fatcat:x2v2wuzj6zgkvm5qtu6mfnqds4

Development Workflow for Manifolds and Fluid Components Based on Laser Powder Bed Fusion

Nicolas Rolinck, Matthias Schmitt, Matthias Schneck, Georg Schlick, Johannes Schilp
2021 Applied Sciences  
(Matthias Schmitt) and M.S. (Matthias Schneck); methodology, N.R. and M.S. (Matthias Schneck); software, N.R.; validation, N.R. and M.S.  ...  (Matthias Schneck); writing-original draft preparation, N.R. and M.S. (Matthias Schmitt); writing-review and editing, M.S. (Matthias Schneck), G.S., J.S.; supervision, J.S.  ... 
doi:10.3390/app11167335 fatcat:qq66bocv6zcythfrqk7ct7gaxa

Global distribution and conservation status of ecologically rare mammal and bird species

Nicolas Loiseau, Nicolas Mouquet, Nicolas Casajus, Matthias Grenié, Maya Guéguen, Brian Maitner, David Mouillot, Annette Ostling, Julien Renaud, Caroline Tucker, Laure Velez, Wilfried Thuiller (+1 others)
2020 Nature Communications  
Identifying species that are both geographically restricted and functionally distinct, i.e. supporting rare traits and functions, is of prime importance given their risk of extinction and their potential contribution to ecosystem functioning. We use global species distributions and functional traits for birds and mammals to identify the ecologically rare species, understand their characteristics, and identify hotspots. We find that ecologically rare species are disproportionately represented in
more » ... IUCN threatened categories, insufficiently covered by protected areas, and for some of them sensitive to current and future threats. While they are more abundant overall in countries with a low human development index, some countries with high human development index are also hotspots of ecological rarity, suggesting transboundary responsibility for their conservation. Altogether, these results state that more conservation emphasis should be given to ecological rarity given future environmental conditions and the need to sustain multiple ecosystem processes in the long-term.
doi:10.1038/s41467-020-18779-w pmid:33033235 fatcat:m6ovzgv7ojdstdnbmakm67xdhi

10. Globale Gesundheit [chapter]

Mathias Egger, Nicola Low, Kathrin Zürcher, Oliver Razum, Matthias Egger, Oliver Razum, Anita Rieder
2017 Public Health Kompakt  
Durch die Globalisierung werden wir zunehmend mit Problemen konfrontiert, welche Landesgrenzen überschreiten. Auch viele gesundheitspolitische Entscheidungen werden heute auf europäischer Ebene oder unter der Mitarbeit internationaler Organisationen getroffen. In diesem Kapitel betrachten wir Gesundheitsindikatoren sowie Krankheits-und Todesursachen im Hinblick auf das Bevölkerungseinkommen und die Entwicklung in verschiedenen Ländern. Wir analysieren die wichtigsten Faktoren, die die
more » ... der Menschen in Industrie-und Entwicklungsländern beeinflussen und beschäftigen uns schließlich mit den Strategien und Akteuren, welche die Globale Gesundheit heute prägen.
doi:10.1515/9783110466867-014 fatcat:ingtcosuebg27dwnio4r4ksmd4

Chirurgische Zugänge zum Tibiakopf

Tim-Nicolas Hissnauer, Matthias Krause, Jannik Frings, Karl-Heinz Frosch
2019 OP-Journal  
ZusammenfassungIntraartikuläre Tibiakopffrakturen sind häufig komplex und können eine große chirurgische Herausforderung darstellen. Das Ziel der operativen Versorgung ist die anatomische stufenlose Gelenkrekonstruktion. Die Frakturmorphologie erfordert eine frakturspezifische Zugangsstrategie, welche entscheidende Voraussetzung für ein gutes postoperatives Ergebnis ist. Um eine komplette visuelle Einsicht über die frakturierten Gelenkflächen zu erlangen, können die verschiedenen Zugänge
more » ... ert oder bedarfsweise erweitert werden. Dabei kann durch eine laterale oder mediale femorale Epikondylenosteotomie die Einsicht auf die betroffene Gelenkfläche maßgeblich verbessert werden. Darüber hinaus ist zu beachten, dass dorsale Anteile der Gelenkfläche meist nur mit dorsalen Zugängen visualisiert werden können! Auch die geplante Positionierung von Platten und Schrauben sollte in der Zugangswahl Berücksichtigung finden!
doi:10.1055/a-0785-1655 fatcat:6ocuqeqzn5cthjpxjxb4fqxvym

Mostly Sunny: A Forecast of Tomorrow's Power Index Research [article]

Sascha Kurz, Nicola Maaser, Stefan Napel, Matthias Weber
2014 arXiv   pre-print
Power index research has been a very active field in the last decades. Will this continue or are all the important questions solved? We argue that there are still many opportunities to conduct useful research with and on power indices. Positive and normative questions keep calling for theoretical and empirical attention. Technical and technological improvements are likely to boost applicability.
arXiv:1405.1510v1 fatcat:hola6zgqvrbmzfk6plwo263kra

Role of the filter functions in noise spectroscopy [article]

Nicola Dalla Pozza, Stefano Gherardini, Matthias M. Müller, Filippo Caruso
2019 arXiv   pre-print
The success of quantum noise sensing methods depends on the optimal interplay between properly designed control pulses and statistically informative measurement data on a specific quantum-probe observable. To enhance the information content of the data and reduce as much as possible the number of measurements on the probe, the filter orthogonalization method has been recently introduced. The latter is able to transform the control filter functions on an orthogonal basis allowing for the optimal
more » ... reconstruction of the noise power spectral density. In this paper, we formalize this method within the standard formalism of minimum mean squared error estimation and we show the equivalence between the solutions of the two approaches. Then, we introduce a non-negative least squares formulation that ensures the non-negativeness of the estimated noise spectral density. Moreover, we also propose a novel protocol for the design in the frequency domain of the set of filter functions. The frequency-designed filter functions and the non-negative least squares reconstruction are numerically tested on noise spectra with multiple components and as a function of the estimation parameters.
arXiv:1911.10598v1 fatcat:eswssewnibc7fptsorrhvbxj3a

Actuarial Adjustments, Retirement Behaviour and Worker Heterogeneity

Matthias Nicolas Giesecke
2014 Social Science Research Network  
Standard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen
more » ... bedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. Abstract The behavioural response with respect to actuarial adjustments in the German public pension system is analysed. The introduction of actuarial adjustments serves as a source of exogenous variation to estimate discrete time transition rates into retirement. The analysis is conducted on administrative data from social security records and on survey data in a comparative scenario. Probability mass points that occur for institutional reasons and due to social norms are controlled for. Moreover, worker heterogeneity is taken into account, which has not been addressed in the previous literature. The results show that on average retirement is postponed by fi ve months due to fi nancial incentives via actuarial adjustments. However, this response is about 40 per cent lower for manual workers compared to non-manual workers which indicates that their retirement income may deteriorate. JEL Classifi cation: C41, H55, J26
doi:10.2139/ssrn.2471598 fatcat:535vw2kap5h4ppmdsegmjxxmtu

Continual Learning from Synthetic Data for a Humanoid Exercise Robot [article]

Nicolas Duczek, Matthias Kerzel, Stefan Wermter
2021 arXiv   pre-print
In order to detect and correct physical exercises, a Grow-When-Required Network (GWR) with recurrent connections, episodic memory and a novel subnode mechanism is developed in order to learn spatiotemporal relationships of body movements and poses. Once an exercise is performed, the information of pose and movement per frame is stored in the GWR. For every frame, the current pose and motion pair is compared against a predicted output of the GWR, allowing for feedback not only on the pose but
more » ... o on the velocity of the motion. In a practical scenario, a physical exercise is performed by an expert like a physiotherapist and then used as a reference for a humanoid robot like Pepper to give feedback on a patient's execution of the same exercise. This approach, however, comes with two challenges. First, the distance from the humanoid robot and the position of the user in the camera's view of the humanoid robot have to be considered by the GWR as well, requiring a robustness against the user's positioning in the field of view of the humanoid robot. Second, since both the pose and motion are dependent on the body measurements of the original performer, the expert's exercise cannot be easily used as a reference. This paper tackles the first challenge by designing an architecture that allows for tolerances in translation and rotations regarding the center of the field of view. For the second challenge, we allow the GWR to grow online on incremental data. For evaluation, we created a novel exercise dataset with virtual avatars called the Virtual-Squat dataset. Overall, we claim that our novel architecture based on the GWR can use a learned exercise reference for different body variations through continual online learning, while preventing catastrophic forgetting, enabling for an engaging long-term human-robot interaction with a humanoid robot.
arXiv:2102.10034v1 fatcat:wmm76qvsmrgbbbxugqcn3msubq

Acoustic source identification using multiple frequency information

Matthias Eller, Nicolas P Valdivia
2009 Inverse Problems  
We consider the inverse problem of identifying the location and shape of a finitely supported acoustic source function, separable with respect to space and frequency, from measurements of the acoustic field on a closed surface for many frequencies. A simple uniqueness proof and an error estimate for the unknown source function are presented. From the uniqueness proof an efficient numerical algorithm for the solution is developed. The algorithm is tested using numerically generated data in dimensions 2 and 3.
doi:10.1088/0266-5611/25/11/115005 fatcat:3n5yvho7fbfdlcajue5ajxeobu

Imprint of Southern Ocean eddies on chlorophyll

Ivy Frenger, Matthias Münnich, Nicolas Gruber
2018 Biogeosciences Discussions  
Although mesoscale ocean eddies are ubiquitous in the Southern Ocean, their spatial and seasonal association with phytoplankton has to date not been quantified in detail. To this end, we identify over 100,000 eddies in the Southern Ocean and determine the associated phytoplankton biomass anomalies using satellite-based chlorophyll-a (Chl) as a proxy. The mean eddy associated Chl anomalies (𝛿Chl) exceed ±10 % over wide regions. The structure of these anomalies is largely zonal,
more » ... with cyclonic, thermocline lifting, eddies having positive anomalies in the subtropical waters north of the Antarctic Circumpolar Current (ACC) and negative anomalies along the ACC. The pattern is similar, but reversed for anticyclonic, thermocline deepening eddies. The seasonality of 𝛿Chl is weak in subtropical waters, but pronounced along the ACC, featuring a seasonal sign switch. The spatial structure and seasonality of 𝛿Chl can be explained largely by lateral advection, especially eddy-<i>stirring</i>. A prominent exception is the ACC region in winter, where 𝛿Chl is consistent with a modulation of phytoplankton light exposure caused by an eddy-induced modification of the mixed layer depth. The clear impact of eddies on phytoplankton may implicate a downstream effect on Southern Ocean biogeochemical properties, such as mode water nutrient contents.
doi:10.5194/bg-2018-70 fatcat:qdpwwzyibvaq7gs2xohtftnkxi
« Previous Showing results 1 — 15 out of 10,722 results