Considerations in the Interpretation of Cosmological Anomalies

Anomalies drive scientific discovery -- they are associated with the cutting edge of the research frontier, and thus typically exploit data in the low signal-to-noise regime. In astronomy, the prevalence of systematics --- both "known unknowns" and "unknown unknowns" --- combined with increasingly large datasets, the widespread use of ad hoc estimators for anomaly detection, and the "look-elsewhere" effect, can lead to spurious false detections. In this informal note, I argue that anomaly detection leading to discoveries of new physics requires a combination of physical understanding, careful experimental design to avoid confirmation bias, and self-consistent statistical methods. These points are illustrated with several concrete examples from cosmology.Comment: An informal summary of an invited talk given at the IAU symposium "Statistical Challenges in 21st Century Cosmology", accepted in the Proceedings IAU Symposium No. 306, 2014 (A.F. Heavens, J.-L. Starck, A. Krone-Martins eds.). 7 pages, 1 figure. Comments welcom

A small, computationally flexible network produces the phenotypic diversity of song recognition in crickets.

How neural networks evolved to generate the diversity of species-specific communication signals is unknown. For receivers of the signals, one hypothesis is that novel recognition phenotypes arise from parameter variation in computationally flexible feature detection networks. We test this hypothesis in crickets, where males generate and females recognize the mating songs with a species-specific pulse pattern, by investigating whether the song recognition network in the cricket brain has the computational flexibility to recognize different temporal features. Using electrophysiological recordings from the network that recognizes crucial properties of the pulse pattern on the short timescale in the cricket Gryllus bimaculatus, we built a computational model that reproduces the neuronal and behavioral tuning of that species. An analysis of the model's parameter space reveals that the network can provide all recognition phenotypes for pulse duration and pause known in crickets and even other insects. Phenotypic diversity in the model is consistent with known preference types in crickets and other insects, and arises from computations that likely evolved to increase energy efficiency and robustness of pattern recognition. The model's parameter to phenotype mapping is degenerate - different network parameters can create similar changes in the phenotype - which likely supports evolutionary plasticity. Our study suggests that computationally flexible networks underlie the diverse pattern recognition phenotypes, and we reveal network properties that constrain and support behavioral diversity

Tevatron-for-LHC Report of the QCD Working Group

The experiments at Run 2 of the Tevatron have each accumulated over 1 inverse femtobarn of high-transverse momentum data. Such a dataset allows for the first precision (i.e. comparisons between theory and experiment at the few percent level) tests of QCD at a hadron collider. While the Large Hadron Collider has been designed as a discovery machine, basic QCD analyses will still need to be performed to understand the working environment. The Tevatron-for-LHC workshop was conceived as a communication link to pass on the expertise of the Tevatron and to test new analysis ideas coming from the LHC community. The TeV4LHC QCD Working Group focussed on important aspects of QCD at hadron colliders: jet definitions, extraction and use of Parton Distribution Functions, the underlying event, Monte Carlo tunes, and diffractive physics. This report summarizes some of the results achieved during this workshop.Comment: 156 pages, Tevatron-for-LHC Conference Report of the QCD Working Grou

Optimisation of Mobile Communication Networks - OMCO NET

The mini conference “Optimisation of Mobile Communication Networks” focuses on advanced methods for search and optimisation applied to wireless communication networks. It is sponsored by Research & Enterprise Fund Southampton Solent University. The conference strives to widen knowledge on advanced search methods capable of optimisation of wireless communications networks. The aim is to provide a forum for exchange of recent knowledge, new ideas and trends in this progressive and challenging area. The conference will popularise new successful approaches on resolving hard tasks such as minimisation of transmit power, cooperative and optimal routing

Lepironia articulata as a sustainable acoustic absorber

Lepironia articulata is found abundant in a swamp and along streams in West Malaysia and it is commonly used for grey water treatment, numerous traditional craft and now commercialise as an organic straw. However, there is a scarcity of knowledge on the physical and acoustical properties of this natural fibre. Therefore, this study was to determine the potential of Lepironia articulata as acoustic absorber. The absorption coefficient was tested using the impedance tube method (ASTM E1050-98) for four different structure arrangements, namely “axial”, “horizontal”, “crossed” and “combination” made up of Lepironia articulata with the diameter ranging from 2 to 4 mm and 4 to 7 mm respectively and the thickness remains at 50 mm. The influence of air gap of 0 to 25 mm, in 5 mm increment was introduced in each sample and other physical properties such as density, porosity and tortuosity were investigated. The results revealed that the Lepironia articulata in horizontal, crossed and combination arrangements showed greatest absorption performance especially in the low frequency range compared to the axial arrangement. If compared between samples with the range diameter of 4 to 7 mm and 2 to 4 mm, bigger stalks diameter in axial arrangement exhibits the least NRC value. Next, air gaps have great influence at low frequency range whereby it shifted the peaks and sound absorption coefficient curve toward lower frequency. Sound absorption coefficient increases as porosity increase and decrease as density�tortuosity increase. Overall, Lepironia articulata has the potential to be used as a sustainable acoustic absorber as all the samples has the NRC value more than or equal to 0.20