Now showing items 1-20 of 1401

    • 1-bit Phase Shifters for Large-Antenna Full-Duplex mmWave Communications 

      da Silva, José Mairton Barros Jr.; Sabharwal, Ashutosh; Fodor, Gábor; Fischione, Carlo (2020)
      Millimeter-wave using large-antenna arrays is a key technological component for the future cellular systems, where it is expected that hybrid beamforming along with quantized phase shifters will be used due to their implementation and cost efficiency. In this paper, we investigate the efficacy of full-duplex mmWave communication with hybrid beamforming ...
    • The 2nu-SVM: A Cost-Sensitive Extension of the nu-SVM 

      Davenport, Mark A. (2005-12-01)
      Standard classification algorithms aim to minimize the probability of making an incorrect classification. In many important applications, however, some kinds of errors are more important than others. In this report we review cost-sensitive extensions of standard support vector machines (SVMs). In particular, we describe cost-sensitive extensions of ...
    • 3-D Local Radon Power Spectra for Seismic Attribute Extraction 

      Steeghs, Philippe; Fokkema, Jacob T; Diephuis, Gerhard (1998-01-15)
      In this paper we discuss a method for volume attribute extraction that is based on a new type of local Radon power spectrum. The new algorithm results in robust and geologically meaningful volume attributes, such as volume dip and azimuth. Seismic volume attribute analysis greatly facilitates the interpretation of large 3-D seismic data volumes. ...
    • 3D Geometry Coding using Mixture Models and the Estimation Quantization Algorithm 

      Lavu, Sridhar (2002-09-01)
      3D surfaces are used in applications such as animations, 3D object modeling and visualization. The geometries of such surfaces are often approximated using polygonal meshes. This thesis aims to compress 3D geometry meshes by using an algorithm based on normal meshes and the Estimation-Quantization (EQ) algorithm. Normal meshes are multilevel ...
    • 3D microfabrication of single-wall carbon nanotube/polymer composites by two-photon polymerization lithography 

      Ushiba, Shota; Shoji, Satoru; Masui, Kyoko; Kuray, Preeya; Kono, Junichiro; (2013)
      We present a method to develop single-wall carbon nanotube (SWCNT)/polymer composites into arbitrary three-dimensional micro/nano structures. Our approach, based on two-photon polymerization lithography, allows one to fabricate three-dimensional SWCNT/polymer composites with a minimum spatial resolution of a few hundreds nm. A near-infrared ...
    • 3D printed fiber optic faceplates by custom controlled fused deposition modeling 

      Wang, Ye; Gawedzinski, John; Pawlowski, Michal E.; Tkaczyk, Tomasz S. (2018)
      A 3D printing technique for manufacturing air-clad coherent fiber optic faceplates is presented. The custom G-code programming is implemented on a fused deposition modeling (FDM) desktop printer to additively draw optical fibers using high-transparency thermoplastic filaments. The 3D printed faceplate consists of 20000 fibers and achieves spatial ...
    • 802.11b Operating in a Mobile Channel: Performance and Challenges 

      Steger, Christopher; Radosavljevic, Predrag; Frantz, Patrick (2003-09-20)
      In the past, the worlds of wireless voice and data transmission have been largely disjoint. Voice traffic has been carried over circuit-switched cellular links, and data has been largely restricted to packet-switched wireless LANs. Now, as consumers demand higher bandwidth connections without sacrificing mobility and traffic transitions from primarily ...
    • A Context-Aware Trust Framework for Resilient Distributed Cooperative Spectrum Sensing in Dynamic Settings 

      Vosoughi, Aida; Cavallaro, Joseph R.; Marshall, Alan (2017)
      Cognitive radios enable dynamic spectrum access where secondary users (SUs) are allowed to operate on the licensed spectrum bands on an opportunistic noninterference basis. Cooperation among the SUs for spectrum sensing is essential for environments with deep shadows. In this paper, we study the adverse effect of insistent spectrum sensing data ...
    • A distinct population of heterogeneously color-tuned neurons in macaque visual cortex 

      Nigam, Sunny; Pojoga, Sorin; Dragoi, Valentin (2021)
      Color is a key feature of natural environments that higher mammals routinely use to detect food, avoid predators, and interpret social signals. The distribution of color signals in natural scenes is widely variable, ranging from uniform patches to highly nonuniform regions in which different colors lie in close proximity. Whether individual neurons ...
    • A framework to identify structured behavioral patterns within rodent spatial trajectories 

      Donnarumma, Francesco; Prevete, Roberto; Maisto, Domenico; Fuscone, Simone; Irvine, Emily M.; (2021)
      Animal behavior is highly structured. Yet, structured behavioral patterns—or “statistical ethograms”—are not immediately apparent from the full spatiotemporal data that behavioral scientists usually collect. Here, we introduce a framework to quantitatively characterize rodent behavior during spatial (e.g., maze) navigation, in terms of movement ...
    • A hyperspectral projector for simultaneous 3D spatial and hyperspectral imaging via structured illumination 

      Xu, Yibo; Giljum, Anthony; Kelly, Kevin F. (2020)
      Both 3D imaging and hyperspectral imaging provide important information of the scene and combining them is beneficial in helping us perceive and understand real-world structures. Previous hyperspectral 3D imaging systems typically require a hyperspectral imaging system as the detector suffers from complicated hardware design, high cost, and high ...
    • A microfluidic-induced C. elegans sleep state 

      Gonzales, Daniel L.; Zhou, Jasmine; Fan, Bo; Robinson, Jacob T. (2019)
      An important feature of animal behavior is the ability to switch rapidly between activity states, however, how the brain regulates these spontaneous transitions based on the animal’s perceived environment is not well understood. Here we show a C. elegans sleep-like state on a scalable platform that enables simultaneous control of multiple environmental ...
    • A Miniaturized QEPAS Trace Gas Sensor with a 3D-Printed Acoustic Detection Module 

      Yang, Xiaotao; Xiao, Youhong; Ma, Yufei; He, Ying; Tittel, Frank K. (2017)
      A 3D printing technique was introduced to a quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor and is reported for the first time. The acoustic detection module (ADM) was designed and fabricated using the 3D printing technique and the ADM volume was compressed significantly. Furthermore, a small grin lens was used for laser focusing and ...
    • A NDIR Mid-Infrared Methane Sensor with a Compact Pentahedron Gas-Cell 

      Ye, Weilin; Tu, Zihan; Xiao, Xupeng; Simeone, Alessandro; Yan, Jingwen; (2020)
      In order to improve the performance of the large divergence angle mid-infrared source in gas sensing, this paper aims at developing a methane (CH4) sensor with non-dispersive infrared (NDIR) technology using a compact pentahedron gas-cell. A paraboloid concentrator, two biconvex lenses and five planar mirrors were used to set up the pentahedron ...
    • A novel mathematical method for disclosing oscillations in gene transcription: A comparative study 

      Antoulas, Athanasios C.; Zhu, Bokai; Zhang, Qiang; York, Brian; O'Malley, Bert W.; (2018)
      Circadian rhythmicity, the 24-hour cycle responsive to light and dark, is determined by periodic oscillations in gene transcription. This phenomenon has broad ramifications in physiologic function. Recent work has disclosed more cycles in gene transcription, and to the uncovering of these we apply a novel signal processing methodology known as the ...
    • A Probabilistic Framework for Deep Learning 

      Patel, Ankit B.; Nguyen, Tan; Baraniuk, Richard G. (2016)
      We develop a probabilistic framework for deep learning based on the Deep Rendering Mixture Model (DRMM), a new generative probabilistic model that explicitly capture variations in data due to latent task nuisance variables. We demonstrate that max-sum inference in the DRMM yields an algorithm that exactly reproduces the operations in deep convolutional ...
    • A room-temperature mid-infrared photodetector for on-chip molecular vibrational spectroscopy 

      Zheng, Bob; Zhao, Hangqi; Cerjan, Ben; Yazdi, Sadegh; Ringe, Emilie; (2018)
      Infrared (IR) photodetection is of major scientific and technical interest since virtually all molecules exhibit characteristic vibrational modes in the mid-infrared region of the spectrum, giving rise to molecular spectroscopy and chemical imaging in this wavelength range. High-resolution IR spectroscopies, such as Fourier Transform IR spectroscopy, ...
    • A Sensitive Carbon Dioxide Sensor Based on Photoacoustic Spectroscopy with a Fixed Wavelength Quantum Cascade Laser 

      Qiao, Shunda; Qu, Yanchen; Ma, Yufei; He, Ying; Wang, Yao; (2019)
      A photoacoustic spectroscopy (PAS) based carbon dioxide (CO2) sensor with a fixed wavelength quantum cascade laser (FW-QCL) was demonstrated. The emission wavelength of the FW-QCL at 4.42 μm in the mid-infrared spectral region matched a fundamental CO2 absorption line. Amplitude modulation of the laser intensity was used to match the resonant ...
    • A Sensitive Carbon Monoxide Sensor Based on Photoacoustic Spectroscopy with a 2.3 μm Mid-Infrared High-Power Laser and Enhanced Gas Absorption 

      Qiao, Shunda; Ma, Yufei; He, Ying; Yu, Xin; Zhang, Zhonghua; (2019)
      A photoacoustic spectroscopy (PAS)-based carbon monoxide (CO) gas sensor with a high-power laser and an enhanced gas absorption was demonstrated. The light source was a distributed feedback (DFB), continuous wave (CW) diode laser with a high output power of ~8 mW to give a strong excitation. The target gas received optical absorption enhanced two ...
    • A terahertz band-pass resonator based on enhanced reflectivity using spoof surface plasmons 

      Liu, Jingbo; Mendis, Rajind; Mittleman, Daniel M. (2013)
      We demonstrate a band-pass resonator in the terahertz (THz) range, based on a frequency-selective designer reflector. The resonator consists of a parallel-plate waveguide, a designed groove pattern cut into the output facet of each plate, and a reflecting mirror. The patterned facet supports a spoof surface plasmon mode, which modifies the reflectivity ...