On the Convergence of Massive MIMO Systems

In this paper we examine convergence properties of massive MIMO systems with the aim of determining the number of antennas required for massive MIMO gains. We consider three characteristics of a channel matrix and study their asymptotic behaviour. Furthermore, we derive ZF SNR and MF SINR for a scenario of unequal receive powers. In our results we include the effects of spatial correlation. We show that the rate of convergence of channel metrics is much slower than that of the ZF/MF precoder properties.Comment: 6 pages, 6 figures, ICC 201

On the Impact of Antenna Topologies for Massive MIMO Systems

Approximate expressions for the spatial correlation of cylindrical and uniform rectangular arrays (URA) are derived using measured distributions of angles of departure (AOD) for both the azimuth and zenith domains. We examine massive multiple-input-multiple-output (MIMO) convergence properties of the correlated channels by considering a number of convergence metrics. The per-user matched filter (MF) signal-to-interference-plus-noise ratio (SINR) performance and convergence rate, to respective limiting values, of the two antenna topologies is also explored.Comment: 6 pages, 6 figure

Identification of Stocked Muskellunge and Potential for Distinguishing Hatchery-Origin and Wild Fish Using Pelvic Fin Ray Microchemistry

The effectiveness of pelvic fin ray microchemistry of muskellunge Esox masquinongy Mitchill to identify stocked individuals along with the potential to identify naturally reproduced fish were evaluated. Fish and water samples were obtained from one hatchery and seven lakes with natural differences in water Sr:Ca to determine whether location-specific environmental signatures were recorded in sectioned muskellunge pelvic fin rays, including fish of known environmental history. Water and fin ray Sr:Ca were strongly correlated. Six lakes in Illinois possessed Sr:Ca signatures that were distinct from the hatchery where muskellunge were raised, resulting in pronounced shifts in Sr:Ca across sectioned fin rays of stocked fish. Hatchery and lake-specific Sr:Ca signatures were stable across years. Sixteen of 19 individual fish known to have been stocked based on PIT tags implanted at stocking were correctly identified as hatchery-origin fish using fin ray core Sr:Ca. Results also indicated that the hatchery Sr:Ca signal can be retained for at least seven years in fin rays of stocked fish. Fin ray microchemistry is a non-lethal approach for determining environmental history of muskellunge that could be used to assess movement patterns in lake and river systems and the degree to which muskellunge populations are supported by natural reproduction and stocking

Early detection of seepage-induced internal erosion using acoustic emission monitoring

Techniques for monitoring water-retaining earth structures are currently limited in their capacity to detect seepage-induced internal erosion (e.g. suffusion) in its early stages, or before serious damage has occurred. Acoustic emission (AE) is widely used in many industries for non-destructive assessment of materials and systems, but despite its advantages it is seldom used in geotechnical engineering as the AE generated by particulate materials is highly complex and difficult to measure and interpret. This project aims to develop the interpretation of AE generated by seepage-induced internal instability phenomena. A continuous, real-time AE early warning system for detecting seepage erosion mechanisms and processes will enable safety-critical decisions to be made. Laboratory testing with a large permeameter apparatus is being used to characterise and quantify the AE generated by the hydromechanical behaviour of a range of internally unstable soils. Initial results show that key processes such as the internal movement of particles can be measured and interpreted using AE

An Observational Study of Tropical Cyclone Spinup in Supertyphoon Jangmi (2008) from 24 to 27 September

The article of record as published may be found at http://dx.doi.org/10.1175/MWR-D-12-00306.1An observational study of tropical cyclone intensification is performed using dropsondes, in situ flight-level data, satellite imagery, and Electra Doppler Radar (ELDORA) during the spinup of Tropical Storm Jangmi (2008) in the western North Pacific. This event was observed with research aircraft during the Tropical Cyclone Structure 2008 (TCS08) field experiment over the course of 3 days as Jangmi intensified rapidly from a tropical storm to a supertyphoon. The dropsonde analysis indicates that the peak azimuthally averaged storm-relative tangential wind speed occurs persistently within the boundary layer throughout the spinup period and suggests that significant supergradient winds are present near and just within the radius of maximum tangential winds. An examination of the ELDORA data in Tropical Storm Jangmi reveals multiple rotating updrafts near the developing eye beneath cold cloud top temperatures ≤ -65°C. In particular, there is a 12-km-wide, upright updraft with a peak velocity of 9m s¯¹ with collocated strong low-level (z < 2 km) convergence of 2 x 10¯³ s¯¹ and intense relative vorticity of 4 x 10¯³ s¯¹. The analysis of the corresponding infrared satellite imagery suggests that vortical updrafts are common before and during rapid intensification. The findings of this study support a recent paradigm of tropical cyclone intensification in which rotating convective clouds are important elements in the spinup process. In a system-scale view of this process, the maximum tangential wind is found within the boundary layer, where the tangential wind becomes supergradient before the air ascends into the eyewall updraft.Naval Postgraduate SchoolOffice of Naval Research (Grant N001408WR20129),National Science FoundationOffice of Naval Research (Grant N001408WR20129

The persistence of modernism in the music and thought of Mathias Spahlinger

This thesis discusses the music and thought of one of Germany’s leading practitioners of contemporary music, composer Mathias Spahlinger. His work will be examined within the framework of studies of modernism in music, and aesthetics more widely, revealing a compositional approach that displays significant continuities with the practice of previous modernists, while also constituting a compellingly critical reinvention of many of their ideas. Through engaging with positions critical of previous modernist music, crucial debates in the composer’s music and thought will be identified, including the modes of listening assumed by modernist composers, implicit hierarchies in the thought and practice of modernist music, and issues of musical autonomy and political effect. In particular, Spahlinger’s unique exploration of the issue of musical autonomy will be considered from two differing perspectives in analyses of his breakthrough orchestral piece, passage/paysage (1990), and the choral work, in dem ganzen ocean von empfindungen eine welle absondern, sie anhalten (1985). It will be shown that these pieces rely on a form of expression in which abstract musical argument and political intention are merged to the point of indivisibility – and that this constitutes a crucial element of Spahlinger’s modernist project. Alongside these two vital examples of the composer’s practice, this thesis will also seek to contextualise the composer within a specifically West German historical situation, and within a wider aesthetic discourse than his own favoured Frankfurt-School-influenced paradigm. To this end, the practice of the poet Hans Magnus Enzensberger, and the painter Anselm Kiefer, will be discussed to argue that the composer is part of a wider, particularly German, strand of modernist thinking; while the work of Jacques Rancière will also be employed as a framework to examine the composer’s intense interest in the politics of musical perception. In considering these broader cultural and aesthetic conditions, this project is wider ranging than previous scholarly contributions in German, and is the most substantial contribution to English-speaking Spahlinger scholarship to date

Population phenomena inflate genetic associations of complex social traits

Heritability, genetic correlation, and genetic associations estimated from samples of unrelated individuals are often perceived as confirmation that genotype causes the phenotype(s). However, these estimates can arise from indirect mechanisms due to population phenomena including population stratification, dynastic effects, and assortative mating. We introduce these, describe how they can bias or inflate genotype-phenotype associations, and demonstrate methods that can be used to assess their presence. Using data on educational achievement and parental socioeconomic position as an exemplar, we demonstrate that both heritability and genetic correlation may be biased estimates of the causal contribution of genotype. These results highlight the limitations of genotype-phenotype estimates obtained from samples of unrelated individuals. Use of these methods in combination with family-based designs may offer researchers greater opportunities to explore the mechanisms driving genotype-phenotype associations and identify factors underlying bias in estimates

KSwAGS: A Swift X-ray and UV Survey of the Kepler Field. I

We introduce the first phase of the Kepler-Swift Active Galaxies and Stars survey (KSwAGS), a simultaneous X-ray and UV survey of ~6 square degrees of the Kepler field using the Swift XRT and UVOT. We detect 93 unique X-ray sources with S/N>3 with the XRT, of which 60 have observed UV counterparts. We use the Kepler Input Catalog (KIC) to obtain the optical counterparts of these sources, and construct the X-ray to optical flux ratio as a first approximation of the classification of the source. The survey produces a mixture of stellar sources, extragalactic sources, and sources which we are not able to classify with certainty. We have obtained optical spectra for thirty of these targets, and are conducting an ongoing observing campaign to fully identify the sample. For sources classified as stellar or AGN with certainty, we construct SEDs using the 2MASS, UBV and GALEX data supplied for their optical counterparts by the KIC, and show that the SEDs differ qualitatively between the source types, and so can offer a method of classification in absence of a spectrum. Future papers in this series will analyze the timing properties of the stars and AGN in our sample separately. Our survey provides the first X-ray and UV data for a number of known variable stellar sources, as well as a large number of new X-ray detections in this well-studied portion of the sky. The KSwAGS survey is currently ongoing in the K2 ecliptic plane fields.Comment: Accepted for publication in the Astronomical Journal. 19 pages, 8 figures, 3 table