Recently, some variants of the l1 norm, particularly matrix norms such as the l1,2 and l 1,∞ norms, have been widely used in multi-task learning, compressed sensing and other related areas to enforce sparsity via joi...
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ISBN:
(纸本)9781617823800
Recently, some variants of the l1 norm, particularly matrix norms such as the l1,2 and l 1,∞ norms, have been widely used in multi-task learning, compressed sensing and other related areas to enforce sparsity via joint regularization. In this paper, we unify the l 1,2 and l1,∞ norms by considering a family of l 1,q norms for 1 1,q norm. Based on this probabilistic interpretation, we develop a probabilistic model using the noninformative Jeffreys prior. We also extend the model to learn and exploit more general types of pairwise relationships between tasks. For both versions of the model, we devise expectation-maximization (EM) algorithms to learn all model parameters, including q, automatically. Experiments have been conducted on two cancer classification applications using microarray gene expression data.
HermesD is a high-rate, low-power wireless transmission system to aid research in neural prosthetic systems for motor disabilities and basic motor neuroscience. It is the third generation of our Hermes systems aimed a...
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HermesD is a high-rate, low-power wireless transmission system to aid research in neural prosthetic systems for motor disabilities and basic motor neuroscience. It is the third generation of our Hermes systems aimed at recording and transmitting neural activity from brain-implanted electrode arrays. This system supports the simultaneous transmission of 32 channels of broadband data sampled at 30 ks/s, 12 b/sample, using frequency-shift keying modulation on a carrier frequency adjustable from 3.7 to 4.1 GHz, with a link range extending over 20 m. The channel rate is 24 Mb/s and the bit stream includes synchronization and error detection mechanisms. The power consumption, approximately 142 mW, is low enough to allow the system to operate continuously for 33 h, using two 3.6-V/1200-mAh Li-SOCl2batteries. The transmitter was designed using off-the-shelf components and is assembled in a stack of three 28 mm × 28-mm boards that fit in a 38 mm × 38 mm × 51-mm aluminum enclosure, a significant size reduction over the initial version of HermesD. A 7-dBi circularly polarized patch antenna is used as the transmitter antenna, while on the receiver side, a 13-dBi circular horn antenna is employed. The advantages of using circularly polarized waves are analyzed and confirmed by indoor measurements. The receiver is a stand-alone device composed of several submodules and is interfaced to a computer for data acquisition and processing. It is based on the superheterodyne architecture and includes automatic frequency control that keeps it optimally tuned to the transmitter frequency. The HermesD communications performance is shown through bit-error rate measurements and eye-diagram plots. The sensitivity of the receiver is - 83 dBm for a bit-error probability of 10-9. Experimental recordings from a rhesus monkey conducting multiple tasks show a signal quality comparable to commercial acquisition systems, both in the low-frequency (local field potentials) and upper-frequency bands (act
Experiments and complimentary simulations are presented to demonstrate the size-dependent infiltration and detection of variable length nucleic acids in porous silicon with controllable pore diameters in the range of ...
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Purpose: A preliminary study on the magnetic resonance (MRI) characteristics of (vegetable) tissue NTIRE is an emerging minimally invasive surgery technique for tissue ablation in which, microsecond, high electrical f...
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作者：
Ramachandra Rao, Raghu AmbekarMehta, Monal R.Leithem, ScottToussaint, Kimani C. Jr.
Department of Electrical and Computer Engineering Urbana-Champaign IL 61820 United States
Department of Mechanical Science and Engineering Urbana-Champaign IL 61820 United States
Affiliate in the departments of Electrical and Computer Engineering and Bioengineering University of Illinois Urbana-Champaign IL 61820 United States
We compare the forward and backward SHG images for porcine tendon, sclera, and ear cartilage using Fourier transform-second-harmonic generation microscopy. The preferred orientation and peaks in the magnitude spectrum...
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With the development of optical coherence tomography,the application optical coherence elastography(OCE)has gained more and more attention in biomechanics for its unique features including micron-scale resolution,real...
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With the development of optical coherence tomography,the application optical coherence elastography(OCE)has gained more and more attention in biomechanics for its unique features including micron-scale resolution,real-time processing,and non-invasive *** this review,one group of OCE techniques,namely dynamic OCE,are introduced and discussed including external dynamic OCE mapping and imaging of ex vivo breast tumor,external dynamic OCE measurement of in vivo human skin,and internal dynamic OCE including acoustomotive OCE and magnetomotive *** techniques overcame some of the major drawbacks of traditional static OCE,and broadened the OCE application *** by scientific needs to engineer new quantitative methods that utilize the high micron-scale resolution achievable with optics,results of biomechanical properties were obtained from biological *** results suggest potential diagnostic and therapeutic clinical *** from these studies also help our understanding of the relationship between biomechanical variations and functional tissue changes in biological systems.
Scanning Kelvin probe microscopy (SKPM) and conductive atomic force microscopy (C-AFM) are used to image surfaces of GaN grown by molecular beam epitaxy (MBE). Numerical simulations are used to assist in the interpret...
Scanning Kelvin probe microscopy (SKPM) and conductive atomic force microscopy (C-AFM) are used to image surfaces of GaN grown by molecular beam epitaxy (MBE). Numerical simulations are used to assist in the interpretation of SKPM images. Detailed analysis of the same area using both techniques allows imaging of surface potential variations arising from the presence of negatively charged dislocations and dislocation-related current leakage paths. Correlations between the charge state of dislocations, conductivity of leakage current paths, and possibly dislocation type can thereby be established. Approximately 25% of the leakage paths appear to be spatially correlated with negatively charged dislocation features. This is approximately the level of correlation expected due to spatial overlap of randomly distributed, distinct features of the size observed, suggesting that the negatively charged dislocations are distinct from those responsible for localized leakage paths found in GaN. The effects of charged dislocation networks on the local potential profile is modeled and discussed.
作者：
Rao, Raghu Ambekar RamachandraMenta, Monal R.Leithem, ScottToussaint Jr., Kimani C.
Department of Electrical and Computer Engineering University of Illinois Urbana-Champaign IL 61820 United States
Department of Mechanical Science and Engineering University of Illinois Urbana-Champaign IL 61820 United States
Departments of Electrical and Computer Engineering and Bioengineering University of Illinois Urbana-Champaign IL 61820 United States
We compare the forward and backward SHG images for porcine tendon, sclera, and ear cartilage using Fourier transform-second-harmonic generation microscopy. The preferred orientation and peaks in the magnitude spectrum...
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作者：
Rao, Raghu Ambekar RamachandraToussaint Jr., Kimani C.
Department of Electrical and Computer Engineering University of Illinois at Urbana-Champaign Urbana IL 61801 United States
Department of Mechanical Science and Engineering University of Illinois at Urbana-Champaign Urbana IL 61801 United States
Departments of Electrical and Computer Engineering Bioengineering Beckman Institute for Advanced Science and Technology University of Illinois at Urbana-Champaign Urbana IL 61801 United States
We discuss the application of harmonic analysis in second-harmonic generation microscopy in developing useful quantitative metrics for assessing tissue morphology. A comparison between the information content in forwa...
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Artificial Immune Systems (AISs) are composed of techniques inspired by immunology. The clonal selection principle ensures the organism adaptation to fight invading antigens by an immune response activated by the bind...
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