Now showing items 1149-1168 of 1532

  • QEPAS based ppb-level detection of CO and N2O using a high power CW DFB-QCL 

    Ma, Yufei; Lewicki, Rafał; Razeghi, Manijeh; Tittel, Frank K. (2013-01-14)
    An ultra-sensitive and selective quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor platform was demonstrated for detection of carbon monoxide (CO) and nitrous oxide (N2O). This sensor used a stateof- the art ...
  • QoS-driven server migration for Internet data centers 

    Ranjan, Supranamaya (2002)
    Many organizations have chosen to host Internet applications at Internet Data Centers (IDCs) located near network access points of the Internet to take advantage of their high availability, large network bandwidths and low ...
  • QRD-QLD searching based sphere detection for emerging MIMO downlink OFDM receivers 

    Radosavljevic, Predrag; Kim, Kyeong Jin; Cavallaro, Joseph R. (2008-11-01)
    In this paper, a detection algorithm with parallel partial candidate-search algorithm is presented. Two fully independent partial search processes are simultaneously employed for two groups of transmit antennas based on ...
  • Quantifying spectral changes experienced by plasmonic nanoparticles in a cellular environment to inform biomedical nanoparticle design 

    Chen, Allen L.; Hu, Ying S.; Jackson, Meredith A.; Lin, Adam Y.; Young, Joseph K.; Langsner, Robert J.; Drezek, Rebekah A. (2014)
    Metal nanoparticles (NPs) scatter and absorb light in precise, designable ways, making them agile candidates for a variety of biomedical applications. When NPs are introduced to a physiological environment and interact ...

  • Quantization of Sparse Representations 

    Boufounos, Petros T.; Baraniuk, Richard G. (2007-01-16)
    Compressive sensing (CS) is a new signal acquisition technique for sparse and compressible signals. Rather than uniformly sampling the signal, CS computes inner products with randomized basis functions; the signal is then ...
  • Quantum Cascade Laser Spectrometer for Trace-Gas Detection of Exhaled Carbonyl Sulfide 

    Wysocki, Gerard; So, Stephen; McCurdy, Matthew; Roller, Chad; Weidman, Daniel; Frantz, Patrick; Curl, Robert; Tittel, Frank K. (2004-05-01)
    Simultaneous concentration measurements of echaled carbonyl sulfide and carbon dioxide were demonstrated using a pulsed quantum cascade laser based gas sensor. This sensor has potential applications in biomedical diagnostics ...
  • Quantum cascade laser-based multipass absorption system for hydrogen peroxide detection 

    Cao, Yingchun; Sanchez, Nancy P.; Jiang, Wenzhe; Ren, Wei; Lewicki, Rafal; Jiang, Dongfang; Griffin, Robert J.; Tittel, Frank K. (2015)
    Hydrogen peroxide (H2O2) is a relevant molecular trace gas species, that is related to the oxidative capacity of the atmosphere, the production of radical species such as OH, the generation of sulfate aerosol via oxidation ...
  • Quartz Enhanced Photoacoustic Spectroscopy Based Trace Gas Sensors Using Different Quartz Tuning Forks 

    Ma, Yufei; Yu, Guang; Zhang, Jingbo; Yu, Xin; Sun, Rui; Tittel, Frank K. (2015)
    A sensitive trace gas sensor platform based on quartz-enhanced photoacoustic spectroscopy (QEPAS) is reported. A 1.395 μm continuous wave (CW), distributed feedback pigtailed diode laser was used as the excitation source ...
  • Quartz-Enhanced Photoacoustic Spectroscopy: A Review 

    Patimisco, Pietro; Scamarcio, Gaetano; Tittel, Frank K.; Spagnolo, Vincenzo (2014)
    A detailed review on the development of quartz-enhanced photoacoustic sensors (QEPAS) for the sensitive and selective quantification of molecular trace gas species with resolved spectroscopic features is reported. The basis ...
  • Quasi-Circular Rotation Invariance in Image Denoising 

    Wan, Yi; Nowak, Robert David (1999-10-20)
    This paper studies a new method for wavelet-based image denoising which is translation invariant (TI) <b>and</b> rotation invariant (RI). These invariances are crucial in image denoising and, more generally, may play ...
  • Quaternion Wavelets for Image Analysis and Processing 

    Chan, Wai Lam; Choi, Hyeokho; Baraniuk, Richard G. (2004-10-01)
    Using the concepts of two-dimensional Hubert transform and analytic signal, we construct a new quaternion wavelet transform (QWT). The QWT forms a tight frame and can be efficiently computed using a-2-D dual-tree filter ...
  • Queuing analysis of long-range-dependent traffic 

    Ribeiro, Vinay Joseph (1998-04-20)
  • A Radially-Gaussian, Signal-Dependent Time-Frequency Representation 

    Baraniuk, Richard G.; Jones, Douglas L. (1991-04-01)
    An optimization formulation for designing signal-dependent kernels that are based on radially Gaussian functions is presented. The method is based on optimality criteria and is not ad hoc. The procedure is automatic. The ...
  • Random Filters for Compressive Sampling and Reconstruction 

    Baraniuk, Richard G.; Wakin, Michael; Duarte, Marco F.; Tropp, Joel A.; Baron, Dror (2006-05-01)
    We propose and study a new technique for efficiently acquiring and reconstructing signals based on convolution with a fixed FIR filter having random taps. The method is designed for sparse and compressible signals, i.e., ...
  • Random observations on random observations: Sparse signal acquisition and processing 

    Davenport, Mark A. (2010)
    In recent years, signal processing has come under mounting pressure to accommodate the increasingly high-dimensional raw data generated by modern sensing systems. Despite extraordinary advances in computational power, ...
  • Random Projections of Signal Manifolds 

    Wakin, Michael; Baraniuk, Richard G. (2006-05-01)
    Random projections have recently found a surprising niche in signal processing. The key revelation is that the relevant structure in a signal can be preserved when that signal is projected onto a small number of random ...
  • Random Projections of Smooth Manifolds 

    Baraniuk, Richard G.; Wakin, Michael (2006-10-01)
    Many types of data and information can be described by concise models that suggest each data vector (or signal) actually has â few degrees of freedomâ relative to its size N. This is the motivation for a variety of ...
  • Randomized Parallel Prefetching and Buffer Management 

    Kallahalla, Mahesh; Varman, Peter J. (1999)
    We show that deterministic algorithms using bounded lookahead cannot fully exploit the potential of a parallel I/O system. Randomization can be used to significantly improve the performance of parallel prefetching and ...
  • Rapid and Continuous Modulation of Hippocampal Network State during Exploration of New Places 

    Kemere, Caleb; Carr, Margaret F.; Karlsson, Mattias P.; Frank, Loren M. (2013-09)
    Hippocampal information processing is often described as two-state, with a place cell state during movement and a reactivation state during stillness. Relatively little is known about how the network transitions between ...