Spin-dependent plasmonics based on interfering topological defects

Observation of spin-dependent plasmonics based on the interference of topological defects in the near-field is presented. We utilize the surface plasmons' scattering dynamics from localized vortex sources to create spinoptical devices as an ensemble of isolated nanoantennas to observe a "giant" spin-dependent plasmonic vortex and a spin-dependent plasmonic focusing lens. The spin-orbit point spread function, a spiral wavefront, is introduced, where the optical spin is a degree of freedom.     

A close-to-capacity dirty paper coding scheme

The "writing on dirty paper"-channel model offers an information-theoretic framework for precoding techniques for canceling arbitrary interference known at the transmitter. It indicates that lossless precoding is theoretically possible at any signal-to-noise ratio (SNR), and thus dirty-paper coding may serve as a basic building block in both single-user and multiuser communication systems. We design an end-to-end coding realization of a system materializing a significant portion of the promised gains. We employ multidimensional quantization based on trellis shaping at the transmitter. Coset decoding is implemented at the receiver using "virtual bits." Combined with iterative decoding of capacity-approaching codes we achieve an improvement of 2dB over the best scalar quantization scheme. Code design is done using the EXIT chart technique.     

CRUST: cryptographic remote untrusted storage without public keys

This paper presents CRUST, a stackable file system layer designed to provide secure file sharing over remote untrusted storage systems. CRUST is intended to be layered over insecure network file systems without changing the existing systems. In our approach, data at rest is kept encrypted, and data integrity and access control are provided by cryptographic means. Our design completely avoids public-key cryptography operations and uses more efficient symmetric-key alternatives to achieve improved performance. As a generic and self-contained system, CRUST includes its own in-band key distribution mechanism and does not rely on any special capabilities of the server or the clients. We have implemented CRUST as a Linux file system and shown that it performs comparably with typical underlying file systems, while providing significantly stronger security.     

Core Self-Evaluations and Job and Life Satisfaction: The Role of Self-Concordance and Goal Attainment.

The present study tested a model explaining how the core self-evaluations (i.e., positive self-regard) concept is linked to job and life satisfaction. The self-concordance model, which focuses on motives underlying goal pursuit, was used as an explanatory framework. Data were collected from 2 samples: (a) 183 university students (longitudinal measures of goal attainment and life satisfaction were used) and (b) 251 employees (longitudinal measures of goal attainment and job satisfaction were utilized). In both studies, the core self-evaluations concept was positively related to goal self-concordance, meaning that individuals with positive self-regard were more likely to pursue goals for intrinsic and identified (value-congruent) reasons. Furthermore, in both studies, goal self-concordance was related to satisfaction (job satisfaction in Study 1 and life satisfaction in Study 2). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The ML decoding performance of LDPC ensembles over Z/sub q/

We derive the asymptotic spectra of low-density parity-check (LDPC) ensembles over Z/sub q/. We consider two ensembles of LDPC matrices, one is binary and the other q-ary. We also show that for modulo-additive noise channels, both ensembles achieve the random coding error exponent, for graphs with sufficiently large connectivity.     

Improving the generalized likelihood ratio test for unknown linear Gaussian channels

In this work, we consider the decoding problem for unknown Gaussian linear channels. Important examples of linear channels are the intersymbol interference (ISI) channel and the diversity channel with multiple transmit and receive antennas employing space-time codes (STC). An important class of decoders is based on the generalized likelihood ratio test (GLRT). Our work deals primarily with a decoding algorithm that uniformly improves the error probability of the GLRT decoder for these unknown linear channels. The improvement is attained by increasing the minimal distance associated with the decoder. This improvement is uniform, i.e., for all the possible channel parameters, the error probability is either smaller by a factor (that is exponential in the improved distance), or for some, may remain the same. We also present an algorithm that improves the average (over the channel parameters) error probability of the GLRT decoder. We provide simulation results for both decoders.     

A noninvasive radiotelemetry system to monitor heart rate for assessing stress responses of bovines.

A noninvasive radiotelemetry system was developed to monitor heart rates of cows and to view and analyze data. The system was validated by comparing heart rate data of two restrained heifers collected simultaneously using telemetric and direct electrocardiogram measurements and by acquiring data over 72 h from two dry cows housed in an experimental handling facility consisting of a free-stall pen, a holding pen, a pass-through stall, and a second holding pen. Telemetric and direct measurements in response to pharmacological elevation of heart rates were essentially identical. For cows in the experimental facility, peristimulus-time histograms indexed to standing or lying showed that average heart rates for cows increased 4.0 +/- 1.4 beats/min after cows stood and decreased 4.8 +/- 1.0 beats/min after cows lay. Similarly, the average heart rate for the cow naive to the facility increased from 60 to 86 beats/min and remained elevated for 6.3 min when heart rate was indexed to maximal heart rate within +/- 3 min of entry into the pass-through stall. Heart rate for the naive cow increased consistently from around 60 to over 160 beats/min during repeated agonistic encounters between animals. Heart rate for the other cow was not affected by the encounters. These results show clearly that heart rate can be used to monitor animal anxiety.     

Near-field Fourier transform polarimetry by use of a discrete space-variant subwavelength grating

We present a unique method for real-time polarization measurement by use of a discrete space-variant subwavelength grating. The formation of the grating is done by discrete orientation of the local subwavelength grooves. The complete polarization analysis of the incident beam is determined by spatial Fourier transform of the near-field intensity distribution transmitted through the discrete subwavelength dielectric grating followed by a subwavelength metal polarizer. We discuss a theoretical analysis based on Stokes-Mueller formalism, as well as on Jones calculus, and experimentally demonstrate our approach with polarization measurements of infrared radiation at a wavelength of 10.6 microm.