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Climate change is becoming a widely recognized risk factor of farmer-herder conflict in Africa. Using an 8 year dataset (Jan 2015 to Sep 2022) of detailed weather and terrain data across four African nations, we apply statistical and machine learning methods to analyze pastoral conflict. We test hypotheses linking these variables with pastoral conflict within each country using geospatial and statistical analysis. Complementing this analysis are risk maps automatically updated for decision-makers. Our models estimate which cells have a high likelihood of experiencing pastoral conflict with high predictive accuracy and study the variation of this accuracy with the granularity of the cells.
The article of Pastore et al, while proposing an interesting and potentially useful approach for the generalisation of Quantum Monte Carlo techniques to the treatment of the nuclear electromagnetic response, features an incorrect and misleading discussion of y-scaling. The response to interactions with transversely polarised virtual photons receives sizeable contributions from non-scaling processes, in which the momentum transfer is shared between two nucleons. It follows that, contrary to what is stated by the the authors, y-scaling in the transverse channel is accidental.
Enthymemes, arguments with unstated premises or conclusions, are pervasive in persuasive discourse, yet their annotation remains notoriously subjective. We present a resource of 1,482 tweets from politically controversial discourse, annotated by five annotators for the presence of enthymemes and their argument structure, designed to study label variation. We first revisit the definition of enthymemes and propose annotation guidelines anchored in Walton's argumentation schemes, offering a structured and constrained approach that nonetheless preserves room for the interpretive nature of the task. This contrasts with past resources, which tend to eliminate disagreement, obscuring its sources and preventing investigation of its potential benefits for model performance. We further propose a complexity analysis of the task, identifying where annotation imposes high cognitive load and may give rise to inconsistent annotation. Our preliminary experiments show that models trained on annotator disagreement outperform models trained on hard majority-vote labels. We close by reflecting on how structural openness in enthymeme definitions and guidelines enables the study of variation in subjecti
This paper is concerned with a cubic nonlinear Schrödinger system modeling the interaction between an optical beam and its third harmonic in a material with Kerr-type nonlinear response. We are mainly interested in the so-called energy-critical case, that is, in dimension four. Our main result states that radially symmetric solutions with initial energy below that of the ground states but with kinetic energy above that of the ground states must blow-up in finite time. The proof of this result is based on the convexity method. As an independent interest we also establish the existence of ground state solutions, that is, solutions that minimize some action functional. In order to obtain our existence results we use the concentration-compactness method combined with variational arguments. As a byproduct, we also obtain the best constant in a vector critical Sobolev-type inequality.
This work is devoted to study the relation between the regularity index and the decay for solutions of the modified Korteweg-de Vries equation in weighted Sobolev spaces. We show if a solution belongs to a Sobolev space and has a large polynomial decay, compared to the regularity, then actually it is more regular than initially considered.
In this paper, we evolve from sparsity, a key concept in robust statistics, to concepts and theoretical results of what we call the mathematics of resilience, at the interface between category theory, the theory of dynamical systems, statistical signal processing and biology. We first summarize a recent result on dynamical systems [Beurier, Pastor, Spivak 2019], before presenting the de-generacy paradigm, issued from biology [Edelman, Gally 1973] and mathematically formalized by [Ehresmann Vanbremeersch 2007] [Ehresmann Vanbremeersch 2019] as the Multiplicity Principle (MP). We then make the connection with statistical signal processing by showing that two distinct and structurally different families of tests satisfy the MP.
Enterprise information systems can be developed following a model-driven paradigm. This way, models that represent the organisational work practice are used to produce models that represent the information system. Current software development methods are starting to provide guidelines for the construction of conceptual models, taking as input requirements models. This paper proposes the integration of two methods: Communication Analysis (a communication-oriented requirements engineering method [España, González et al. 2009]) and the OO-Method (a model-driven object-oriented software development method [Pastor and Molina 2007]). For this purpose, a systematic technique for deriving OO-Method Conceptual Models from business process and requirements models is proposed. The business process specifications (which include message structures) are processed in order to obtain static and dynamic views of the computerised information system. Then, using the OLIVANOVA framework, software source code can be generated automatically [CARE Technologies].
The moment method is used to prove the exact controllability of a wide class of bidimensional linear dispersive PDE's posed on the two-dimensional torus $\mathbb{T}^{2}.$ The control function is considered to be acting on a small vertical and horizontal strip of the torus. Our results apply to several well-known models including some bidimesional extensions of the Benajamin-Ono and Korteweg-de Vries equations. As a by product, the exponential stabilizability with any given decay rate is also established in $H^{s}_{p}(\mathbb{T}^{2}),$ with $s\geq 0,$ by constructing an appropriated feedback control law.
This report describes de design of an experiment that intends to compare two variants of a modeldriven system development method, so as to assess the impact of requirements engineering practice in the quality of the conceptual models. The conceptual modelling method being assessed is the OO-Method [Pastor and Molina 2007]. One of its variants includes Communication Analysis, a communication-oriented requirements engineering method [España, González et al. 2009] and a set of guidelines to derive conceptual models from requirements models [España, Ruiz et al. 2011; González, España et al. 2011]. The other variant is an ad-hoc, text-based requirements practice similar to the one that is applied in industrial projects by OO-Method practitioners. The goal of the research, summarised according to the Goal/Question/Metric template [Basili and Rombach 1988], is to: *) analyse the resulting models of two model-based information systems analysis method variants; namely, the OO-Method (OOM) and the integration of Communication Analysis and the OO-Method (CA+OOM), *) for the purpose of carrying out a comparative evaluation *) with respect to performance of the subject and acceptance of the met
NASA is preparing for future astronaut landings on the Moon with an unusually ambitious orbital rehearsal。 During Artemis III in 2027, Orion astronauts will rendezvous and dock separately with prototype lunar landers from Blue Origin and SpaceX, allowing crews and ground teams to test the complex maneuvers needed for later missions
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Europa’s hidden ocean has made the icy moon one of the solar system’s most promising places to search for habitable conditions。 Scientists have hoped that water from this deep ocean might rise through cracks and form shallow reservoirs that future spacecraft could more easily study。 New simulations suggest that journey is unlikely because turbulent
Sweden could become an important source of rare earth elements needed for magnets and green technologies。 Instead of extracting one target metal, researchers are cataloging everything contained in Swedish mineral deposits。 They will then develop magnets using those naturally available combinations, potentially reducing pollution, waste, and relianc
NASA’s Swift Observatory observed a supermassive black hole ripping apart a star more than 30,000 light-years from the center of a distant galaxy。 The extraordinary flare briefly outshone its entire host galaxy in ultraviolet light and revealed a black hole about a million times the Sun’s mass
JWST has captured unusually detailed images of gas feeding the supermassive black hole at the center of NGC 4696。 A vast filament appears to funnel material into an 800-light-year-wide spinning disk, where gas races around at up to 600 kilometers per second。 The findings suggest black holes may recycle their own fuel by heating gas with jets and la
A new theoretical study offers a possible explanation for how the Universe can grow more complex without violating the second law of thermodynamics。 Using a quantum gravity framework called Gravity from Entropy, mathematician Ginestra Bianconi found that the Universe’s total entropy may rise as space expands, even while entropy within each unit of