On the trade-off between energy efficiency and estimation error in compressive sensing

Compressive sensing (CS) refers to the process of reconstructing a signal that is supposed to be sparse or compressible. CS has wide applications, such as in cognitive radio networks. In this paper, we investigate effective CS schemes for the trade-off between energy efficiency and estimation error. We propose an enhancement to a Bayesian estimation approach and an enhancement to the isotonic regression approach that is based on nearly isotonic regression. We also show how to compute the routing matrix for selecting active sensor nodes. The proposed enhancements are evaluated with trace-driven simulations. Considerable gaps are observed between the original approaches and the proposed enhancements in the simulation results. The near isotonic regression method achieves the best performance among all the CS schemes examined in this paper.     

Benzannulation through Ruthenium(0)-Catalyzed Transfer Hydrogenative Cycloaddition: Precision Synthesis and Photophysical Characterization of Soluble Diindenoperylenes

The first application of ruthenium(0)-catalyzed 1,2-dione-diyne [2+2+2] cycloaddition to PAH construction is achieved by the precision synthesis of soluble diindenoperylenes (DIPs), the electronic structures of which were investigated using steady-state absorption and emission, transient absorption, cyclic voltammetry and time-dependent density functional theory     

Connected graphs switching equivalent to their iterated line graphs

In this paper, the problem of determining graphs which are switching equivalent to at least one of their iterated line graphs is considered, and such connected graphs are characterized.     

CuI/l-proline-catalyzed selective one-step mono-acylation of styrenes and stilbenes

Vicinal di-oxygenation of styrene-type olefins was achieved with cheaper, less toxic CuI in the presence of l-proline as ligand and NaIO₄ as the oxidant. This approach provides a straightforward and efficient access to mono-acylated diols from both styrene and stilbene derivatives with good to excellent yields and diastereoselectivity.     

Syntheses of Novel 3-Substituted-2′-deoxy-3-deazauridine Nucleosides

Syntheses of novel 3-ethynyl (8), 3-vinyl (10) and 3-acetoxy (13)-2′-deoxy-3-deazauridine analogs starting from the protected 2′-deoxy-3-deazauridine derivative 4 are described.     

Surface-enhanced Raman scattering of methyl <Emphasis Type="Italic">p</Emphasis>-hydroxy benzoate: A molecular orientational study

The surface geometry of a methyl p-hydroxy benzoate (MPHB) molecule was studied by analysis of the SERS spectra adsorbed on silver colloid surfaces. For a reliable analysis of the SERS spectrum, we also performed density functional theoretical calculations. The large enhancement of the in-plane ring-stretching and ring-stretching modes in the surface-enhanced Raman scattering spectrum indicates that the molecule is adsorbed on the silver surface in a stand on orientation of MPHB on a silver surface.     

Extracting secret keys from integrated circuits

Modern cryptographic protocols are based on the premise that only authorized participants can obtain secret keys and access to information systems. However, various kinds of tampering methods have been devised to extract secret keys from conditional access systems such as smartcards and ATMs. Arbiter-based physical unclonable functions (PUFs) exploit the statistical delay variation of wires and transistors across integrated circuits (ICs) in manufacturing processes to build unclonable secret keys. We fabricated arbiter-based PUFs in custom silicon and investigated the identification capability, reliability, and security of this scheme. Experimental results and theoretical studies show that a sufficient amount of inter-chip variation exists to enable each IC to be identified securely and reliably over a practical range of environmental variations such as temperature and power supply voltage. We show that arbiter-based PUFs are realizable and well suited to build, for example, key-cards that need to be resistant to physical attacks.     

Solving covering problems using LPR-based lower bounds

Unate and binate covering problems are a subclass of general integer linear programming problems with which several problems in logic synthesis, such as two-level logic minimization and technology mapping, are formulated. Previous branch-and-bound methods for solving these problems exactly use lower bounding techniques based on finding maximal independent sets. In this paper, we examine lower bounding techniques based on linear programming relaxation (LPR) for the covering problem. We show that a combination of traditional reductions (essentiality and dominance) and incremental computation of LPR-based lower bounds can exactly solve difficult covering problems orders of magnitude faster than traditional methods     

Statistical timing analysis of combinational logic circuits

Efficient methods for computing an exact probability distribution of the delay of a combinational circuit, given probability distributions for the gate and wire delays, are developed. The derived distribution can give the probability that a combinational circuit will achieve a certain performance, across the possible range. This information can then be used to predict the expected performance of the entire circuit. The techniques presented target fast analysis as well as reduced memory requirements. The notion of a correct approximation, based on convex inequality, which never overestimates the percentage of circuits that will achieve any given performance is defined. It is shown that given the assumption that all the topologically longest paths are responsible for the delay, the computation technique provides a correct probabilistic measure in the sense given above. Methods are given to identify and to ignore false paths in the probabilistic analysis, so as to obtain correct and less pessimistic answers to the performance prediction question. Some practical results are given for a number of benchmark combinational circuits