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In this paper, we consider the problem of detecting a primary user in a cognitive radio network by employing multiple antennas at the cognitive receiver. In vehicular applications, cognitive radios typically transit regions with differing densities of primary users. Therefore, speed of detection is key, and so, detection based on a small number of samples(More)
Through the study of single molecules it has become possible to explain the function of many of the complex molecular assemblies found in cells. The protein titin provides muscle with its passive elasticity. Each titin molecule extends over half a sarcomere, and its extensibility has been studied both in situ and at the level of single molecules. These(More)
This paper's findings suggest that an arbitrary Chinese policy that greatly increases total suspended particulates (TSPs) air pollution is causing the 500 million residents of Northern China to lose more than 2.5 billion life years of life expectancy. The quasi-experimental empirical approach is based on China's Huai River policy, which provided free winter(More)
We used force-clamp atomic force microscopy to measure the end-to-end length of the small protein ubiquitin during its folding reaction at the single-molecule level. Ubiquitin was first unfolded and extended at a high force, then the stretching force was quenched and protein folding was observed. The folding trajectories were continuous and marked by(More)
We present in this paper a linear blind multiuser receiver, referred to as the Capon receiver, for code-division multiple-access (CDMA) systems utilizing multiple transmit antennas and space-time (ST) block coding. The Capon receiver is designed by exploiting signal structures imposed by both spreading and ST coding. We highlight the unique ST coding(More)
In this paper, we investigate how reductions of barriers to migration affect the decision of middle school graduates to attend high school in rural China. Change in the cost of migration is identified using exogenous variation across counties in the timing of national identity card distribution, which make it easier for rural migrants to register as(More)
This paper examines differential binary modulation for wireless networks that utilize wireless relays to seek cooperative diversity and improved performance. Two differential cooperative transmission schemes, referred to as differential amplify-and-forward (DAF) and differential decode-and-forward (DDF), respectively, are introduced. These schemes require(More)
A Markov-like weighted least squares (WLS) estimator is presented herein for harmonic sinusoidal parameter estimation. The estimator involves two distinct steps whereby it "rst obtains a set of initial parameter estimates that neglect the harmonic structure by some standard sinusoidal parameter estimation technique, and then the initial parameter estimates(More)
C economic reforms, which have been in flux for three decades, have more than doubled China’s economic growth, from an average of 4.4 percent annually before 1978 to an average of 9.5 percent after 1978. Even more impressively, the contribution of TFP to the growth has increased from 11 percent before 1978 to more than 40 percent afterwards (Dwight H.(More)
Immunoglobulin-like modules are common components of proteins that play mechanical roles in cells such as muscle elasticity and cell adhesion. Mutations in these proteins may affect their mechanical stability and thus may compromise their function. Using single molecule atomic force microscopy (AFM) and protein engineering, we demonstrate that point(More)