Probabilistic Inference from Arbitrary Uncertainty using Mixtures of Factorized Generalized Gaussians

This paper presents a general and efficient framework for probabilistic inference and learning from arbitrary uncertain information. It exploits the calculation properties of finite mixture models, conjugate families and factorization. Both the joint probability density of the variables and the likelihood function of the (objective or subjective) observation are approximated by a special mixture model, in such a way that any desired conditional distribution can be directly obtained without numerical integration. We have developed an extended version of the expectation maximization (EM) algorithm to estimate the parameters of mixture models from uncertain training examples (indirect observations). As a consequence, any piece of exact or uncertain information about both input and output values is consistently handled in the inference and learning stages. This ability, extremely useful in certain situations, is not found in most alternative methods. The proposed framework is formally justified from standard probabilistic principles and illustrative examples are provided in the fields of nonparametric pattern classification, nonlinear regression and pattern completion. Finally, experiments on a real application and comparative results over standard databases provide empirical evidence of the utility of the method in a wide range of applications

GROUNDWATER RESTORATION FOLLOWING IN-SITU LEACH MINING OF URANIUM

From 1950 to the early 1980’s New Mexico played an important role in the production of uranium (U) for the nuclear power industry and the nation’s weapon programs. Though the U mining and milling industry in New Mexico is inactive at present, increased interest in nuclear energy as a CO2 free power source has led to proposals for renewed development of U resources. In particular, U mining projects have been proposed using both underground mining and in situ leach (ISL) mining. When feasible, ISL mining minimizes waste by eliminating; mine waste, mine dewatering, radiation exposure and the recovered U does not require milling with consequent production of milling wastes. However, ISL does not completely avoid environmental impacts and it does produce some wastes which must be managed at the surface. A much greater concern is restoration of groundwater quality following completion of mining operations. This research consisted of 4 phases. Phase 1 involved collection of samples representative of ore materials that might be mined by ISL processes and characterization of their composition and characteristics. Phase 2 consisted of leach studies to determine the leachability of U from the ore materials and to generate an understanding of the expected chemistry after reaction with bicarbonate and dissolved oxygen which are used in ISL lixiviants. Phases 3 and 4 column experiments for the investigation of aquifer stabilization methods that might be used to restore groundwater following the completion of ISL mining. Phase 3 investigated the use of chemical methods while Phase 4 considered application of biological processes. Results from batch experiments suggest that U and co-constituents are released after reaction of ore solids with bicarbonate and dissolved oxygen showing the potential impacts of ISL U mining on groundwater quality. Column leach experiments were conducted to investigate the potential of chemical and biological processes for restoration. The addition of phosphate was used to immobilize U(VI) by chemical precipitation. Sodium lactate was used as an electron donor for the activation of sulfate and metal reducing bacteria, and a control column without a chemical or biological reductant was used to interpret results differences. Given column experiment results, effluent concentrations of U and co-constituents for chemical and biological treatments are similar to those of the control, suggesting limited mixing between the contaminated groundwater and amended restoration fluid. Groundwater restoration should consider hydrodynamics, specifically the mixing that takes place in the interstitial pores within the aquifer

Implementación de un sistema de control para el sistema nacional de contratación publica

The project seeks that all preferential processes comply 100% with the purpose for which they were created, which is promoting the micro and small entrepreneurs originally from where it is to make the purchase, delivery or performance of service the work. We will be able to confirm address information, financial statements, the volume of assets in a truthful and provide us the Internal Revenue Service which is responsible for checking the veracity of them. For these processes of engagement which are very attractive to providers as an opportunity to be awarded is very high, overlooking the fact that manipulate their information by making false information is grounds for suspension of the National Register of Suppliers. In this way our system of control that will optimize the savings and especially the participation of micro and small entrepreneurs and artisans, because processes and contribution minor there is a marked preference for this group of suppliers. The initial investment of this project is 8840 because we only have to equip the space you already have the National Institute of Public Procurement within its administrative offices in the city of Quito

Probing the "μ\mu from ν\nu" supersymmetric standard model with displaced multileptons from the decay of a Higgs boson at the LHC

The "$\mu$ from $\nu$" supersymmetric standard model ($\mu\nu$SSM) cures the $\mu$-problem and concurrently reproduces measured neutrino data by using a set of usual right-handed neutrino superfields. Recently, the LHC has revealed the first scalar boson which naturally makes it tempting to test $\mu\nu$SSM in the light of this new discovery. We show that this new scalar while decaying to a pair of unstable long-lived neutralinos, can lead to a distinct signal with non-prompt multileptons. With concomitant collider analysis we show that this signal provides an unmistakable signature of the model, pronounced with light neutralinos. Evidence of this signal is well envisaged with sophisticated displaced vertex analysis, which deserves experimental attention.Comment: 5 pages, 3 figures, title, text, abstract and references modifie

Hunting physics beyond the standard model with unusual W±W^\pm and ZZ decays

Nonstandard on-shell decays of $W^\pm$ and $Z$ bosons are possible within the framework of extended supersymmetric models, i.e., with singlet states and/or new couplings compared to the minimal supersymmetric standard model. These modes are typically encountered in regions of the parameter space with light singlet-like scalars, pseudoscalars, and neutralinos. In this letter we emphasize how these states can lead to novel signals at colliders from $Z$- or $W^\pm$-boson decays with prompt or displaced multileptons/tau jets/jets/photons in the final states. These new modes would give distinct evidence of new physics even when direct searches remain unsuccessful. We discuss the possibilities of probing these new signals using the existing LHC run-I data set. We also address the same in the context of the LHC run-II, as well as for the future colliders. We exemplify our observations with the "$\mu$ from $\nu$" supersymmetric standard model, where three generations of right-handed neutrino superfields are used to solve shortcomings of the minimal supersymmetric standard model. We also extend our discussion for other variants of supersymmetric models that can accommodate similar signatures.Comment: New discussions and references added, 8 pages, 1 figure, matches with the published version in Phys. Rev.

Non-linear response of single-molecule magnets: field-tuned quantum-to-classical crossovers

Quantum nanomagnets can show a field dependence of the relaxation time very different from their classical counterparts, due to resonant tunneling via excited states (near the anisotropy barrier top). The relaxation time then shows minima at the resonant fields H_{n}=n D at which the levels at both sides of the barrier become degenerate (D is the anisotropy constant). We showed that in Mn12, near zero field, this yields a contribution to the nonlinear susceptibility that makes it qualitatively different from the classical curves [Phys. Rev. B 72, 224433 (2005)]. Here we extend the experimental study to finite dc fields showing how the bias can trigger the system to display those quantum nonlinear responses, near the resonant fields, while recovering an classical-like behaviour for fields between them. The analysis of the experiments is done with heuristic expressions derived from simple balance equations and calculations with a Pauli-type quantum master equation.Comment: 4 pages, 3 figures. Submitted to Phys. Rev. B, brief report

A Chandra View Of Nonthermal Emission In The Northwestern Region Of Supernova Remnant RCW 86: Particle Acceleration And Magnetic Fields

The shocks of supernova remnants (SNRs) are believed to accelerate particles to cosmic ray (CR) energies. The amplification of the magnetic field due to CRs propagating in the shock region is expected to have an impact on both the emission from the accelerated particle population, as well as the acceleration process itself. Using a 95 ks observation with the Advanced CCD Imaging Spectrometer (ACIS) onboard the Chandra X-ray Observatory, we map and characterize the synchrotron emitting material in the northwestern region of RCW 86. We model spectra from several different regions, filamentary and diffuse alike, where emission appears dominated by synchrotron radiation. The fine spatial resolution of Chandra allows us to obtain accurate emission profiles across 3 different non-thermal rims in this region. The narrow width (l = 10''-30'') of these filaments constrains the minimum magnetic field strength at the post-shock region to be approximately 80 {\mu}G.Comment: 7 pages, 3 figures, submitted for publication at the Astrophysical Journa

Impact of disorder on dynamics and ordering in the honeycomb-lattice iridate Na2IrO3

Kitaev's honeycomb spin-liquid model and its proposed realization in materials such as α-RuCl3, Li2IrO3, and Na2IrO3 continue to present open questions about how the dynamics of a spin liquid are modified in the presence of non-Kitaev interactions as well as the presence of inhomogeneities. Here we use Na23 nuclear magnetic resonance to probe both static and dynamical magnetic properties in single-crystal Na2IrO3. We find that the NMR shift follows the bulk susceptibility above 30 K but deviates from it below; moreover below TN the spectra show a broad distribution of internal magnetic fields. Both of these results provide evidence for inequivalent magnetic sites at low temperature, suggesting inhomogeneities are important for the magnetism. The spin-lattice relaxation rate is isotropic and diverges at TN, suggesting that the Kitaev cubic axes may control the critical quantum spin fluctuations. In the ordered state, we observe gapless excitations, which may arise from site substitution, emergent defects from milder disorder, or possibly be associated with nearby quantum paramagnetic states distinct from the Kitaev spin liquid