Detection of Mines in Acoustic Images using Higher Order Spectral Features

A new pattern-recognition algorithm detects approximately 90% of the mines hidden in the Coastal Systems Station Sonar0, 1, and 3 databases of cluttered acoustic images, with about 10% false alarms. Similar to other approaches, the algorithm presented here includes processing the images with an adaptive Wiener filter (the degree of smoothing depends on the signal strength in a local neighborhood) to remove noise without destroying the structural information in the mine shapes, followed by a two-dimensional FIR filter designed to suppress noise and clutter, while enhancing the target signature. A double peak pattern is produced as the FIR filter passes over mine highlight and shadow regions. Although the location, size, and orientation of this pattern within a region of the image can vary, features derived from higher order spectra (HOS) are invariant to translation, rotation, and scaling, while capturing the spatial correlations of mine-like objects. Classification accuracy is improved by combining features based on geometrical properties of the filter output with features based on HOS. The highest accuracy is obtained by fusing classification based on bispectral features with classification based on trispectral features

Relative pay and job satisfaction: some new evidence

This paper investigates the determinants of job satisfaction using data from the National Educational Longitudinal Study. The determinants of interest include actual pay, relative pay, hours of work, job autonomy and several personal characteristics. We also investigate the determinants of satisfaction with pay conditional on a worker's satisfaction with other domains of job satisfaction, such as satisfaction with job security. We find that relative pay is statistically significant but that its effect on satisfaction with pay is relatively small. Job autonomy has a powerful influence on satisfaction with pay. So too does being black.JOB SATISFACTION WAGES AUTONOMY SECURITY

Inferring models of bacterial dynamics toward point sources

Experiments have shown that bacteria can be sensitive to small variations in chemoattractant (CA) concentrations. Motivated by these findings, our focus here is on a regime rarely studied in experiments: bacteria tracking point CA sources (such as food patches or even prey). In tracking point sources, the CA detected by bacteria may show very large spatiotemporal fluctuations which vary with distance from the source. We present a general statistical model to describe how bacteria locate point sources of food on the basis of stochastic event detection, rather than CA gradient information. We show how all model parameters can be directly inferred from single cell tracking data even in the limit of high detection noise. Once parameterized, our model recapitulates bacterial behavior around point sources such as the "volcano effect". In addition, while the search by bacteria for point sources such as prey may appear random, our model identifies key statistical signatures of a targeted search for a point source given any arbitrary source configuration

Has the U.S.-Vietnam Bilateral Trade Agreement Led to Higher FDI into Vietnam?

In December 2001, a Bilateral Trade Agreement (BTA) came into effect that normalized economic relations between the United States and Vietnam. The resulting surge in trade surpassed most expectations. The impact of the BTA on FDI, however, has been less visible, especially with regard to U.S. FDI into Vietnam. This paper uses new data that accounts for FDI by U.S. subsidiaries resident in third counties to show that U.S. firms have been much more aggressive investors in Vietnam than normally reported in typical bilateral FDI data using Balance of Payments definitions of capital flows. While the U.S. is widely reported as the 11th largest investor into Vietnam, the new data shows that U.S.-related FDI exceeded all other countries in 2004. Although a formal model is not developed, descriptive data supports strongly the conclusion that the BTA has had a major impact on FDI into Vietnam, especially with regard to FDI from U.S. multinationals.FDI; Trade Agreement

The framing and fashioning of therapeutic citizenship among people living with HIV taking Antiretroviral Therapy in Uganda

In this article, we examine how people living with HIV (PLWH) were able to reconceptualize or “reframe” their understanding of HIV and enhance their capacity to self-manage the condition. Two in-depth interviews were held with 38 PLWH (20 women, 18 men) selected from three government and nongovernment antiretroviral therapy (ART) delivery sites in Wakiso District, and the narratives analyzed. ART providers played an important role in shaping participants’ HIV self-management processes. Health workers helped PLWH realize that they could control their condition, provided useful concepts and language for emotional coping, and gave advice about practical self-management tasks, although this could not always be put into practice. ART providers in this setting were spaces for the development of a collective identity and a particular form of therapeutic citizenship that encouraged self-management, including adherence to ART. Positive framing institutions are important for many PLWH in resource-limited settings and the success of ART programs