Transmission Rank Selection for Opportunistic Beamforming with Quality of Service Constraints

In this paper, we consider a multi-cell multi-user MISO broadcast channel. The system operates according to the opportunistic beamforming framework in a multi-cell environment with variable number of transmit beams (may alternatively be referred as the transmission rank) at each base station. The maximum number of co-scheduled users in a cell is equal to its transmission rank, thus increasing it will have the effect of increasing the multiplexing gain. However, this will simultaneously increase the amount of interference in the network, which will decrease the rate of communication. This paper focuses on optimally setting the transmission rank at each base station such that a set of Quality of Service (QoS) constraints, that will ensure a guaranteed minimum rate per beam at each base station, is not violated. Expressions representing the achievable region of transmission ranks are obtained considering different network settings. The achievable transmission rank region consists of all achievable transmission rank tuples that satisfy the QoS constraints. Numerical results are also presented to provide further insights on the feasibility problem.Comment: To appear in IEEE ICC 2014, Sydney, Australi

A Closer Look at Spatiotemporal Convolutions for Action Recognition

In this paper we discuss several forms of spatiotemporal convolutions for video analysis and study their effects on action recognition. Our motivation stems from the observation that 2D CNNs applied to individual frames of the video have remained solid performers in action recognition. In this work we empirically demonstrate the accuracy advantages of 3D CNNs over 2D CNNs within the framework of residual learning. Furthermore, we show that factorizing the 3D convolutional filters into separate spatial and temporal components yields significantly advantages in accuracy. Our empirical study leads to the design of a new spatiotemporal convolutional block "R(2+1)D" which gives rise to CNNs that achieve results comparable or superior to the state-of-the-art on Sports-1M, Kinetics, UCF101 and HMDB51

Neighbourhood greenspace quantity, quality and socioeconomic inequalities in mental health

There is tentative evidence suggesting that socioeconomically disadvantaged groups may benefit more from access to neighbourhood greenspace and therefore could be a lever for narrowing socioeconomic inequalities (‘equigenesis’) in mental health, although studies are equivocal. One potential explanation for this inconsistency is differences in study designs, particularly how greenspace is measured. Most previous studies are from high income countries, and there has been no investigations into equigenic environments in China. Using survey data collected from 26 neighbourhoods in Guangzhou, China, this study examines whether local greenspaces may narrow socioeconomic inequalities in health (i.e. equigenesis) in the Chinese context. The study is the first to explore the contribution of greenspace in reducing socioeconomic inequalities in mental health in the Chinese context. It uses Normalized Difference Vegetation Index (NDVI), Street View Greenness (SVG) and self-reported neighbourhood greenness quality as estimates of residential greenness exposure Results show that SVG-quantity, SVG-quality and self-reported greenspace quality narrow the neighbourhood socioeconomic inequalities in mental health. Our findings demonstrate the importance of improving equity in local green infrastructure for promoting health equity through urban planning and design, including improving access to green spaces, and providing more street trees in socioeconomically disadvantaged neighbourhoods

Measuring Information Leakage in Website Fingerprinting Attacks and Defenses

Tor provides low-latency anonymous and uncensored network access against a local or network adversary. Due to the design choice to minimize traffic overhead (and increase the pool of potential users) Tor allows some information about the client's connections to leak. Attacks using (features extracted from) this information to infer the website a user visits are called Website Fingerprinting (WF) attacks. We develop a methodology and tools to measure the amount of leaked information about a website. We apply this tool to a comprehensive set of features extracted from a large set of websites and WF defense mechanisms, allowing us to make more fine-grained observations about WF attacks and defenses.Comment: In Proceedings of the 2018 ACM SIGSAC Conference on Computer and Communications Security (CCS '18

Multidrug-resistant Escherichia coli and Tetracycline-resistant Enterococcus faecalis in wild raptors of Alabama and Georgia, USA

Wild birds inhabit in a wide variety of environments and can travel great distances. Thus, wild birds can possibly spread antimicrobial resistance along the way, and this may represent a potential public health concern. We characterized antimicrobial resistance in fecal Escherichia coli and Enterococcus faecalis in wild raptors in the southeastern US. Cloacal samples were collected from 118 wild raptors of 17 species from 18 counties in Alabama and 15 counties in Georgia. A total of 112 E. coli and 76 E. faecalis isolates were recovered, and we found significantly more antimicrobial-resistant E. coli (20/112, 18%) than E. faecalis (6/76, 8%; P = 0.05). Five antimicrobial-resistant genes: blaTEM-1, blaCTX-M-1, tet(M), cmlA, cat, and gyrA, were identified in antimicrobial-resistant E. coli isolates. Five of 13 (38%) ampicillin-resistant E. coli harbored both bla-TEM-1 and blaCTX-M-1 genes, indicating they are extended-spectrum beta-lactamase-carrying strains. Both of the tetracycline resistance genes, tet(M) and tet(L), were identified in E. faecalis isolates. Wild raptors seem to be a reservoir host of antimicrobial-resistant E. coli and E. faecalis and may represent a hazard to animal and human health by transmission of these isolates

Tropical pseudolinear and pseudoquadratic optimization as parametric mean-payoff games

We apply an approach based on parametric mean-payoff games to develop bisection and Newton schemes for solving problems of tropical pseudolinear and pseudoquadratic optimisation with general two-sided constraints.Comment: 30 pages (with appendices), 9 figure

Multiple shift second order sequential best rotation algorithm for polynomial matrix EVD

In this paper, we present an improved version of the second order sequential best rotation algorithm (SBR2) for polynomial matrix eigenvalue decomposition of para-Hermitian matrices. The improved algorithmis entitledmultiple shift SBR2 (MS-SBR2) which is developed based on the original SBR2 algorithm. It can achieve faster convergence than the original SBR2 algorithm by means of transferring more off-diagonal energy onto the diagonal at each iteration. Its convergence is proved and also demonstrated by means of a numerical example. Furthermore, simulation results are included to compare its convergence characteristics and computational complexity with the original SBR2, sequential matrix diagonalization (SMD) and multiple shift maximum element SMD algorithms

Coordination among ERP Consultants: Controlling Mechanisms

Consultants are deemed critical to the success of an ERP implementation because of the breadth and complexity of the system, the management of multiple modules, and the one-time nature of the project that limits desire to increase investment in a permanent workforce. However, consultants often fail to effectively coordinate their activities, making integration of the ERP problematic. Coordination across module implementation of the ERP is essential to the overall success. Achievements of consultants are often controlled by organizations though the negotiated contract, but just how do consultants apply controls to meet their obligations and reach an effective level of integration for the system? A qualitative analysis of consultant perspectives on coordination controls will serves as the basis of the study. Grounded theory techniques will be applied to surface appropriate controls applied by consultants. Taiwan ERP consultants serve as the interview cases. We expect that the level of knowledge of the tasks and procedures could be a determinant of the choice of control mechanisms adopted by ERP consultants firms

Order-controlled multiple shift SBR2 algorithm for para-hermitian polynomial matrices

In this work we present a new method of controlling the order growth of polynomial matrices in the multiple shift second order sequential best rotation (MS-SBR2) algorithm which has been recently proposed by the authors for calculating the polynomial matrix eigenvalue decomposition (PEVD) for para-Hermitian matrices. In effect, the proposed method introduces a new elementary delay strategy which keeps all the row (column) shifts in the same direction throughout each iteration, which therefore gives us the flexibility to control the polynomial order growth by selecting shifts that ensure non-zero coefficients are kept closer to the zero-lag plane. Simulation results confirm that further order reductions of polynomial matrices can be achieved by using this direction-fixed delay strategy for the MS-SBR2 algorithm