Now showing items 41-60 of 1765

    • Client Beamforming for Rate Scalability of MU-MIMO Networks 

      Yu, Hang (2015-04-24)
      The multi-user MIMO (MU-MIMO) technology allows an AP with multiple antennas to simultaneously serve multiple clients to improve the network capacity. To achieve this, the AP leverages zero-forcing beamforming (ZFBF) to ...
    • Protocol Design and Experimental Evaluation for Efficient Multi-User MIMO Wireless Networks 

      Bejarano Chavez, Oscar (2015-04-24)
      Information theoretic results on Multi-User MIMO (MU-MIMO) have demonstrated a many-fold increase in capacity compared to Single-Input Single-Output. By leveraging multiple antennas at the Access Point (AP) and beamforming ...
    • MU-MIMO WLANs in Diverse Bands and Environments 

      Anand, Narendra (2015-04-24)
      Multi-user MIMO (MU-MIMO) is a precoding technique that allows for an Access Point (AP) to transmit data to multiple receivers in parallel resulting in an overall capacity increase. However, achieving these gains requires ...
    • Imaging Plasmons with Compressive Hyperspectral Microscopy 

      Lu, Liyang (2015-04-23)
      With the ability of revealing the interactions between objects and electromagnetic waves, hyperspectral imaging in optical microscopy is of great importance in the study of various micro/nano-scale physical and chemical ...
    • WrAP: Hardware and Software Support for Atomic Persistence in Storage Class Memory 

      Giles, Ellis Robinson (2015-04-23)
      In-memory computing is gaining popularity as a means of sidestepping the performance bottlenecks of traditional block-based storage devices. However, the volatile nature of DRAM makes these systems vulnerable to system ...
    • Compressive Sensing in Positron Emission Tomography (PET) Imaging 

      Valiollahzadeh, Majid (2015-04-16)
      Positron emission tomography (PET) is a nuclear medicine functional imaging modality, applicable to several clinical problems, but especially in detecting the metabolic activity (as in cancer). PET scanners use multiple ...
    • Virtual Ring Buffer for Camera Application Concurrency 

      Reyes, Jose Eduardo (2015-01-26)
      Smartphones with integrated cameras have inspired a growing number of real- time, computer vision applications. Existing camera software architectures, however, do not support concurrency: only one application accesses the ...
    • Circular Differential Scattering of Single Chiral Self-Assembled Gold Nanorod Dimers 

      Wang, Lin-Yung; Smith, Kyle W.; Dominiquez-Medina, Sergio; Moody, Nicole; Olson, Jana M.; Zhang, Huanan; Chang, Wei-Shun; Kotov, Nicholas; Link, Stephan (2015)
      Circular dichroism spectroscopy is essential for structural characterization of proteins and chiral nanomaterials. Chiral structures from plasmonic materials have extraordinary strong circular dichroism effects compared ...
    • New approaches in quartz-enhanced photoacoustic sensing 

      Sampaolo, Angelo; Patimisco, Pietro; Pennetta, Riccardo; Scamarcio, Gaetano; Tittel, Frank K. (2015)
      We report on the design and realization of custom quartz tuning forks with different geometries and sizes aimed to improve the photoacoustic effect in quartz-enhanced photoacoustic (QEPAS) sensor systems. A detailed analysis ...
    • Focused terahertz waves generated by a phase velocity gradient in a parallel-plate waveguide 

      McKinney, Robert W.; Monnai, Yasuaki; Mendis, Rajind; Mittleman, Daniel (2015)
      We demonstrate the focusing of a free-space THz beam emerging from a leaky parallel-plate waveguide (PPWG). Focusing is accomplished by grading the launch angle of the leaky wave using a PPWG with gradient plate separation. ...
    • Decision-Directed Channel Estimation Implementation for Spectral Efficiency Improvement in Mobile MIMO-OFDM 

      Ketonen, Johanna; Juntti, Markku; Ylioinas, Jari; Cavallaro, Joseph R. (2015)
      Channel estimation algorithms and their implementations for mobile receivers are considered in this paper. The 3GPP long term evolution (LTE) based pilot structure is used as a benchmark in a multiple-input multiple-o ...
    • Photoluminescence of a Plasmonic Molecule 

      Huang, Da; Byers, Chad P.; Wang, Lin-Yung; Hoggard, Anneli; Hoener, Ben; Chang, Wei-Shun; Landes, Christy F.; Link, Stephan (2015)
      Photoluminescent Au nanoparticles are appealing for biosensing and bioimaging applications because of their non-photobleaching and non-photoblinking emission. The mechanism of one-photon photoluminescence from plasmonic ...
    • Non-intrusive Persistence with a Backend NVM Controller 

      Pu, Libei; Doshi, Kshitij; Giles, Ellis; Varman, Peter (2015)
      By providing instruction-grained access to vast amounts of persistent data with ordinary loads and stores, byte-addressable storage class memory (SCM) has the potential to revolutionize system architecture. We describe a ...
    • Transaction local aliasing in storage class memory 

      Giles, Ellis; Doshi, Kshitij; Varman, Peter (2015)
      This paper describes a lightweight software library to solve the challenges [6], [3], [1], [5], [2] of programming storage class memory (SCM). It provides primitives to demarcate failure-atomic code regions. SCM loads and ...
    • Extraordinary sensitivity enhancement by metasurfaces in terahertz detection of antibiotics 

      Xie, Lijuan; Gao, Weilu; Shu, Jie; Ying, Yibin; Kono, Junichiro (2015)
      We have detected trace amounts of molecules of antibiotics (kanamycin sulfate) dispersed on metasurfaces with terahertz (THz) spectroscopy. Utilizing the extraordinary optical transmission resonance of an array of square-shaped ...
    • Superfluorescence from photoexcited semiconductor quantum wells: Magnetic field, temperature, and excitation power dependence 

      Cong, Kankan; Wang, Yongrui; Kim, Ji-Hee; Noe, G. Timothy II; McGill, Stephen A.; Belyanin, Alexey; Kono, Junichiro (2015)
      Superfluorescence (SF) is a many-body process in which a macroscopic polarization spontaneously builds up from an initially incoherent ensemble of excited dipoles and then cooperatively decays, producing a delayed pulse ...
    • Direct Plasmon-Driven Photoelectrocatalysis 

      Robatjazi, Hossein; Bahauddin, Shah Mohammad; Doiron, Chloe; Thomann, Isabell (2015)
      Harnessing the energy from hot charge carriers is an emerging research area with the potential to improve energy conversion technologies. Here we present a novel plasmonic photoelectrode architecture carefully designed to ...
    • Charge Transfer Plasmons: Optical Frequency Conductances and Tunable Infrared Resonances 

      Wen, Fangfang; Zhang, Yue; Gottheim, Samuel; King, Nicholas S.; Zhang, Yu; Nordlander, Peter; Halas, Naomi J. (2015)
      A charge transfer plasmon (CTP) appears when an optical-frequency conductive pathway between two metallic nanoparticles is established, enabling the transfer of charge between nanoparticles when the plasmon is excited. ...
    • Distinguishing between plasmon-induced and photoexcited carriers in a device geometry 

      Zheng, Bob Y.; Zhao, Hangqi; Manjavacas, Alejandro; McClain, Michael; Nordlander, Peter (2015)
      The use of surface plasmons, charge density oscillations of conduction electrons of metallic nanostructures, to boost the efficiency of light-harvesting devices through increased light-matter interactions could drastically ...