Comment on "Support Vector Machines with Applications"

Comment on "Support Vector Machines with Applications" [math.ST/0612817]Comment: Published at http://dx.doi.org/10.1214/088342306000000475 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Effect of quantum and thermal jitter on the feasibility of Bekenstein’s proposed experiment to search for Planck-scale signals

A proposed experiment to test whether space is discretized [J. D. Bekenstein, Phys. Rev. D 86, 124040 (2012); Found. Phys. 44, 452 (2014)] is based on the supposed impossibility of an incident photon causing a displacement of a transparent block by less than the Planck length. An analysis of the quantum and thermal jitter of the block shows that it greatly diminishes the possibility that the experiment could reveal Planck-scale signals

Lithium in strong magnetic fields

The electronic structure of the lithium atom in a strong magnetic field 0 <= gamma <= 10 is investigated. Our computational approach is a full configuration interaction method based on a set of anisotropic Gaussian orbitals that is nonlinearly optimized for each field strength. Accurate results for the total energies and one-electron ionization energies for the ground and several excited states for each of the symmetries ^20^+, ^2(-1)^+, ^4(-1)^+, ^4(-1)^-, ^2(-2)^+, ^4(-2)^+, $^4(-3)^{+}$ are presented. The behaviour of these energies as a function of the field strength is discussed and classified. Transition wave lengths for linear and circular polarized transitions are presented as well.Comment: 12 pages, 13 figures, accepted for publication in Phys. Rev.

Ensemble Forecasting of Major Solar Flares: Methods for Combining Models

One essential component of operational space weather forecasting is the prediction of solar flares. With a multitude of flare forecasting methods now available online it is still unclear which of these methods performs best, and none are substantially better than climatological forecasts. Space weather researchers are increasingly looking towards methods used by the terrestrial weather community to improve current forecasting techniques. Ensemble forecasting has been used in numerical weather prediction for many years as a way to combine different predictions in order to obtain a more accurate result. Here we construct ensemble forecasts for major solar flares by linearly combining the full-disk probabilistic forecasts from a group of operational forecasting methods (ASAP, ASSA, MAG4, MOSWOC, NOAA, and MCSTAT). Forecasts from each method are weighted by a factor that accounts for the method's ability to predict previous events, and several performance metrics (both probabilistic and categorical) are considered. It is found that most ensembles achieve a better skill metric (between 5\% and 15\%) than any of the members alone. Moreover, over 90\% of ensembles perform better (as measured by forecast attributes) than a simple equal-weights average. Finally, ensemble uncertainties are highly dependent on the internal metric being optimized and they are estimated to be less than 20\% for probabilities greater than 0.2. This simple multi-model, linear ensemble technique can provide operational space weather centres with the basis for constructing a versatile ensemble forecasting system -- an improved starting point to their forecasts that can be tailored to different end-user needs.Comment: Accepted for publication in the Journal of Space Weather and Space Climat

Investigating the function of prehistoric stone bowls and griddle stones in the Aleutian Islands by lipid residue analysis

The earliest durable cooking technologies found in Alaska are stone bowls and griddle stones recovered from the Aleutian Islands. This article aims to identify the function of these artefacts. Molecular and chemical analyses of carbonised residues found on their surfaces confirm that these artefacts were used to process marine resources. Both artefacts have high lipid content and C:N ratios, suggesting they were used to process oily substances. Stable isotope results of individual lipids suggest that they were used to process different sets of resources within the aquatic spectrum as griddle stones have slightly more 13C-depleted lipids than stone bowls, possibly indicating more variable use. Integration of these results with archaeological and ethnographic data leads us to infer that griddle stones were used for cooking a diversity of aquatic resources, possibly with the addition of plant foods, whereas stone bowls were specifically used to render marine mammal fats. We further hypothesize that a sudden peak in stone bowl frequencies at 4000–3000 cal yr BP was connected to a Neoglacial cold spell bringing sea ice conditions to the Aleutian Islands. This may have led to new subsistence strategies in which the rendering of marine mammal fats played a central role

Editorial: Long-Term Perspectives on Circumpolar Social-Ecological Systems

Modern climate change is having profound environmental impacts at the world's higher latitudes, leading to the disappearance of sea ice, the melting of permafrost and the northward shift of major biogeographic zones. These changing conditions have consequences for contemporary Arctic Indigenous peoples and their traditional lifeways. As planning and mitigation efforts intensify, there is renewed interest in looking back through time to understand how past Arctic societies were able to maintain a long-term—and often highly-resilient —presence in these ever-changing ecosystems. Of particular interest is how past groups coped with earlier changes in climate, both shorter-term “shocks” as well as longer-term up- and downturns in temperatures. A number of recent publications have highlighted the abundance of high-resolution and human-scale data that archaeology is uniquely positioned to contribute to this discussion (Riede, 2014; Jackson et al., 2018; Fitzhugh et al., 2018). So far, however, the practical integration of such long-term “paleo-” perspectives on specific future-orientated planning and management efforts has been limited. For example, the Arctic Council's Arctic Resilience Report (2016)—an in-depth comparative analysis of fragility and resilience in numerous local circumpolar social-ecological systems—acknowledges the importance of “deep history”, and the role of flexibility and traditional knowledge, while the chronological coverage of all 25 local case-studies remains firmly rooted in the present and very recent historical past. The overarching aim of this Special Issue is to explore the gap in knowledge between archaeological understandings of long-term Arctic adaptations and the practical application of these insights to the future-oriented challenges of sustainability and cultural survival. The first objective is to illustrate the wealth and diversity of archaeological research that is currently taking place in both the northern and southern polar regions. The issue showcases a selection of case-studies focusing on long-term human-environment interactions, integrating archaeological, climatic and paleoecological datasets. A wide range of insights emerge in terms of cultural responses to specific climatic fluctuations, but also in terms of longer-term cultural trajectories, including major shifts in settlement, subsistence, demography and interaction networks, all of which can be understood in terms of fragility and resilience in particular social-ecological systems. Another objective of the volume is to stimulate reflection and debate about what these archaeological datasets—and the long-term insights that emerge—can contribute to future planning and mitigation efforts. Seventeen papers in this issue “look back”, examining human-environment interactions in three regions: Arctic Eurasia; Arctic North America and Greenland; and Sub-Antarctic South America. Conversely, three papers “look ahead”, exploring emerging challenges and future implications. We conclude this editorial with a series of recommendations – or “action points” – that are addressed to the wider interdisciplinary research community

From Dyck Paths to Standard Young Tableaux

We present nine bijections between classes of Dyck paths and classes of standard Young tableaux (SYT). In particular, we consider SYT of flag and rectangular shapes, we give Dyck path descriptions for certain SYT of height at most 3, and we introduce a special class of labeled Dyck paths of semilength n that is shown to be in bijection with the set of all SYT with n boxes. In addition, we present bijections from certain classes of Motzkin paths to SYT. As a natural framework for some of our bijections, we introduce a class of set partitions which in some sense is dual to the known class of noncrossing partitions