Journal Article Square-root lasso: pivotal recovery of sparse signals via conic programming Get access A. Belloni, Belloni Duke University, Fuqua School Business, 100 Street, Durham, North Carolina 27708, U.S.A.abn5@duke.edu Search for other works by this author on: Oxford Academic Google Scholar V. Chernozhukov, Chernozhukov Massachusetts Institute Technology, Department Economics, 52 Memorial Drive, Cambridge, 02142, U.S.A.vchern@mit.edu L. Wang Mathematics, 77 Avenue, 02139,...

We have reported a novel type of partially polarized dissipative soliton in mode-locked erbium-doped all-fiber laser with strong net normal dispersion. The output pulses exhibit as quasi-trapezoid spectral profiles 3-dB width large 83 nm. maximum pulse energy and peak power approach 75 nJ 6 kW at the available pump 1 W, respectively. Experimental observations show that polarization state broadband changes along cavity position from totally to polarized, which is distinct typical completely...

The material point method is ideally suited to modelling problems involving large deformations where conventional mesh-based methods would struggle. However, total and updated Lagrangian approaches are unsuitable non-ideal, respectively, in terms of formulating equilibrium for the method. This due basis functions, particularly derivatives normally being defined on an unformed, sometimes regular, background mesh. It possible map function spatial using deformation at a but this introduces...

A broadly tunable dual-wavelength erbium-doped ring fiber laser based on a high-birefringence loop mirror (HiBi-FLM) and polarization controller is demonstrated experimentally. The measured transmission spectrum of HiBi-FLM covers wide range from 1525 to 1575 nm. wavelength proposed can be flexibly during this ∼50 nm by adjusting the controller. In addition, spacing two wavelengths adjustable changing length HiBi fiber. lasers with 1 2 m are experimentally compared. experimental results show...

We have experimentally observed a new kind of ultra-broadband high-energy dissipative soliton pulse in compact erbium-doped all-fiber laser with long cavity length and large net normal dispersion. The characteristics evolution processes are quite distinct from those reported previous literatures. Remarkablely, the spectral width pulses increases whereas duration decreases increase pump power, so energy peak power monotonically. At maximum available 1.1 W, this fiber delivers 3-dB bandwidth...

A kernel-independent treecode (KITC) is presented for fast summation of particle interactions. The method employs barycentric Lagrange interpolation at Chebyshev points to approximate well-separated particle-cluster KITC requires only kernel evaluations, suitable non-oscillatory kernels, and it utilizes a scale-invariance property interpolation. For given level accuracy, the reduces operation count pairwise interactions from $O(N^2)$ $O(N\log N)$, where $N$ number particles in system....

In this paper, we focus on the decentralized optimization problem over Stiefel manifold, which is defined a connected network of $d$ agents. The objective an average local functions, and each function privately held by agent encodes its data. agents can only communicate with their neighbors in collaborative effort to solve problem. existing methods, multiple rounds communications are required guarantee convergence, giving rise high communication costs. contrast, paper proposes algorithm,...

We report on experimental observations of dual-wavelength solitons in a passively mode-locked erbium-doped fiber laser. Two kinds with different spectrum shapes are achieved. One is exhibited to have sidebands and the other one shown smooth profile without any sideband. The mode-locking mechanism at central wavelengths analyzed. Experimental results suggest that pump level together cavity filtering effect play key roles generation solitons.

We propose a class of multipliers correction methods to minimize differentiable function over the Stiefel manifold. The proposed combine value reduction step with proximal step. former one searches along an arbitrary descent direction in Euclidean space instead vector tangent Meanwhile, latter minimizes first-order approximation objective range current iterate make Lagrangian associated orthogonality constraints symmetric at any accumulation point. global convergence has been established for...

<p>To address the problem of low localization accuracy in node algorithms wireless sensor networks (WSN) based on received signal strength indication (RSSI) ranging, a WSN algorithm ranging optimization and graph is proposed. In terms RSSI outliers are removed using Grubbs method, data processed moving average smoothing-Gaussian hybrid filter to establish Bessel function model reduce error; localization, employed construct distance cost term, built these terms, adopted minimize this...

We have investigated and compared the pulse evolutions in low ultra-large anomalous dispersion erbium-doped fiber lasers mode-locked by nonlinear polarization rotation technique. Two deliver pulses that exhibit quite distinct characteristics such as duration, spectral width, sidebands. Experimental observations show width decreases from several nanometers to less than one nanometer whereas duration extends about three times changing cavity −0.03 −15.50 ps2. The solitons laser dips optical...

Supercontinuum (SC) generation is experimentally achieved in a compact all-fiber laser system by using high-energy wave-breaking-free dissipative soliton (DS) pulses. The pulses exhibit Gaussian (rectangular) shape profiles spectral (temporal) domain, which even reversed of the typical rectangular-spectrum DSs. With increase pump power pulse duration enlarges dramatically whereas bandwidth and peak keep almost constant, enables to accumulate much higher energy during pulse-shaping process....

In this paper, two low-complexity adaptive step size algorithms are investigated for blind beamforming. Both of them used in a stochastic gradient (SG) algorithm, which employs the constrained constant modulus (CCM) criterion as design approach. A brief analysis is given illustrating their properties. Simulations performed to compare performances novel with other well-known methods. Results indicate that proposed achieve superior performance, better convergence behavior and lower...

The Stokeslet and stresslet kernels are commonly used in boundary element simulations singularity methods for slow viscous flow. Evaluating the velocity induced by a collection of Stokeslets stresslets direct summation requires $O(N^2)$ operations, where $N$ is system size. present work develops treecode algorithm 3D that reduces cost to $O(N\log N)$. particles divided into hierarchy clusters, well-separated particle-cluster interactions computed far-field Cartesian Taylor approximation....

We report on the evolution of dissipative-soliton laser from single pulse to soliton molecule, lastly multiple pulses. The experimental observations show that separation molecules is oscillating stochastically. It found proposed fiber delivers pulses a two solitons, molecule together with soliton, and three respectively, when, pump strength enhanced gradually.

We have experimentally investigated supercontinuum generation in a conventional single-mode fiber pumped with nanosecond pulse source. The experimental results show that, when pump power increases, the spectral flatness is improved obviously and broadening only occurs red-shifted radiation rather than blue-shifted radiation. A source reported of 4.7 dB over 180 nm (ranging from 1555 to >1735 nm) at P R = 5 W predicted less 1 > 8 W. cascade stimulated Raman scattering (SRS) together soliton...

The numerous recruitment information and the asymmetry between college majors work posts make it difficult for students to seize job opportunities that conform their occupational values, employment success rate is always at a low level. effect of current student career recommendation systems usually unsatisfactory, existing haven’t fully considered role students’ values in instructing employment. To fill this research blank, paper studied method based on values. At first, proposed...

In this paper, several reported blind adaptive beam- forming algorithms, including the stochastic gradient (SG) methods and recursive least squares (RLS) are reviewed. Then, conjugate (CG) algorithm is introduced as a tradeoff between SG RLS algorithms. On basis of idea, novel constrained constant modulus (CCM) design criterion described employed for deriving modified optimization algorithm, which does not require information desired user beforehand. Simulations performed to compare...