An event-based architecture for solving constraint satisfaction problems

Constraint satisfaction problems (CSPs) are typically solved using conventional von Neumann computing architectures. However, these architectures do not reflect the distributed nature of many of these problems and are thus ill-suited to solving them. In this paper we present a hybrid analog/digital hardware architecture specifically designed to solve such problems. We cast CSPs as networks of stereotyped multi-stable oscillatory elements that communicate using digital pulses, or events. The oscillatory elements are implemented using analog non-stochastic circuits. The non-repeating phase relations among the oscillatory elements drive the exploration of the solution space. We show that this hardware architecture can yield state-of-the-art performance on a number of CSPs under reasonable assumptions on the implementation. We present measurements from a prototype electronic chip to demonstrate that a physical implementation of the proposed architecture is robust to practical non-idealities and to validate the theory proposed.Comment: First two authors contributed equally to this wor

Well-posedness results for triply nonlinear degenerate parabolic equations

We study the well-posedness of triply nonlinear degenerate elliptic-parabolic-hyperbolic problem $$b(u)_t - {\rm div} \tilde{\mathfrak a}(u,\nabla\phi(u))+\psi(u)=f, \quad u|_{t=0}=u_0$$ in a bounded domain with homogeneous Dirichlet boundary conditions. The nonlinearities $b,\phi$ and $\psi$ are supposed to be continuous non-decreasing, and the nonlinearity $\tilde{\mathfrak a}$ falls within the Leray-Lions framework. Some restrictions are imposed on the dependence of $\tilde{\mathfrak a}(u,\nabla\phi(u))$ on $u$ and also on the set where $\phi$ degenerates. A model case is $\tilde{\mathfrak a}(u,\nabla\phi(u)) =\tilde{\mathfrak{f}}(b(u),\psi(u),\phi(u))+k(u)\mathfrak{a}_0(\nabla\phi(u)),$ with $\phi$ which is strictly increasing except on a locally finite number of segments, and $\mathfrak{a}_0$ which is of the Leray-Lions kind. We are interested in existence, uniqueness and stability of entropy solutions. If $b=\mathrm{Id}$, we obtain a general continuous dependence result on data $u_0,f$ and nonlinearities $b,\psi,\phi,\tilde{\mathfrak{a}}$. Similar result is shown for the degenerate elliptic problem which corresponds to the case of $b\equiv 0$ and general non-decreasing surjective $\psi$. Existence, uniqueness and continuous dependence on data $u_0,f$ are shown when $[b+\psi](\R)=\R$ and $\phi\circ [b+\psi]^{-1}$ is continuous

Rhythmic inhibition allows neural networks to search for maximally consistent states

Gamma-band rhythmic inhibition is a ubiquitous phenomenon in neural circuits yet its computational role still remains elusive. We show that a model of Gamma-band rhythmic inhibition allows networks of coupled cortical circuit motifs to search for network configurations that best reconcile external inputs with an internal consistency model encoded in the network connectivity. We show that Hebbian plasticity allows the networks to learn the consistency model by example. The search dynamics driven by rhythmic inhibition enable the described networks to solve difficult constraint satisfaction problems without making assumptions about the form of stochastic fluctuations in the network. We show that the search dynamics are well approximated by a stochastic sampling process. We use the described networks to reproduce perceptual multi-stability phenomena with switching times that are a good match to experimental data and show that they provide a general neural framework which can be used to model other 'perceptual inference' phenomena

Ameliorating Drought-Induced Stress in Turfgrass through Genetic Manipulation

To delineate the major processes associated with short water scarcity in four tall fescue species, we examined their enzymatic and nonenzymatic antioxidant activity and FaSGR expression levels. Moreover, we examined the possibility of Agrobacterium-mediated transformation of Arabidopsis P5CS1 gene in tall fescue. According to the results, proline has been introduced as an important compatible osmolyte, so as to protect enzymes and cellular structures under water scarcity. In addition to that, superoxide dismutase (SOD) along with proline can be used as a core physiological indicator for the assessment of adaptability to environmental conditions. Results indicated that most of the superoxide that was produced as a result of drought stress was converted to H2O2 by SOD and subsequently detoxified by ascorbate peroxidase (APX) into H2O. Notably, the FaSGR transcript increased drastically over the course of the drought stress in Pixie and Mini-mustang, in contrast to jaguar and h–d, supporting the notion of Stay GReen (SGR)-mediated chlorophyll degradation in the less drought-tolerant cultivars. Different modulations of ROSs quenching system in tall fescue genotypes suggest that even one stress signal causes different signaling responses in different cultivars. The heterologous transformation of P5CS1 in Festuca arundinacea background, confirmed by PCR and transient GUS assay, most probably can improve tall fescue tolerance to drought stress

Degradation of Addition Polymers by Ultrasonic Waves and the Role of Cavitation

Abstract Not Provided

Multivariate data analysis for monitoring the quality of the commercialized bottled water in Bangladesh

Dissertation presented as the partial requirement for obtaining a Master's degree in Statistics and Information Management, specialization in Information Analysis and ManagementSeveral multivariate statistical or chemometrics or pattern recognition techniques e.g. Principal Component Analysis, Factor Analysis, Hierarchical and Non-Hierarchical k-Mean Cluster Analysis have been applied to gain understanding about the quality of the packaged bottled drinking water in the market of Bangladesh. Twenty three (23) physico-chemical properties of total of 51 water samples have been investigated. The data set consists of 49 individuals from 11 Brands and 2 deionized ASTM TYPE-I water samples produced in the laboratory to be a technically pure water having Electrical Conductivity ~0.056 μS-cm-1. Descriptive statistics, analysis of variance, Non-Parametric Kruskal-Wallis tests have been conducted to detect statistical differences between the water types and different brands. Total of 23 attributes of water covering major ion contents: sodium, potassium, calcium, magnesium, iron, manganese, chloride, fluoride, sulphate, bicarbonate and nitrate and other features: pH, temperature, total dissolved solids, electrical conductivity, hardness, ammonium, nitrite, free cyanogen and chemical oxygen demand, total cation sum and total anion sum. Both the Principal Components Analysis and the Factor Analysis revealed that the differences between water individuals are best characterized by four Principal Components or Factors indicating material loadings, hardness or softness aesthetic acceptability and lightness/sutability for human consumption. Hierarchical and Non- Hierarchical k-means Cluster Analysis clearly identified the presence of four distinct clusters: A, B, C and D among the bottled water products in the market of Bangladesh. The profile features for each cluster have been defined as such the classification achieved to acquire improved and detailed understanding of the general properties of the products under study. We have observed that HCA using WARD algorithm provided us with more realistic classification solution in comparison with non-hierachical k-means as the Cluster members are truly reflecting their group pattern in line with their chemical compositions. HCA using WARD showed that BRAND05 and BRAND11 belonging to Cluster A products execssively loaded with materials and considered to be as hard waters. And BRAND09 and BRAND10 staying with DEIONIZEDWATER belonging to Cluster B are completely devoide of essential minerals as such seemed to be as ultra low mineral content type water or too soft in nature. The other folks BRAND03, BRAND04, BRAND06, BRAND07 and BRAND08 are also not having sufficient mineral contents so as to be very soft water indeed. Hence, waters belonging to Clusters A, B and C are not suitable for human consumption. Only two brands BRAND01 and BRAND02 staying in Cluster D appeared to be suitable for human consumption in every respect.The fact is the BRAND01 is produced by a foreign manufacturer. That means, all other local brands, except BRAND02 are essentially not having the appropriate quality to be drinking waters. From both PCA and FA these two brands BRAND01 and BRAND02 have been very well explained. These are the major outcomes of this study not immediately apparent from univariate approach or not appeared from the data set while looking through naked eyes. It is revealed that the multivariate data analytical techniques have potential to be useful complementary techniques to support the existing univariate practices for industrial quality assurance quality control, market surveillance, standardization process and or regulatory purposes and also seemed to be interesting to academic and scientific communities seeking advanced knowledge

Influence of Classification on Information Filtering

Vast amounts of information are available via the Internet and there are indications that the volume of scholarly information shared across the Internet is increasing [Okerson, 1995]. Tools such as WAIS, Lycos and Webcrawler have been developed to allow users to access information, but these tools require the user to be actively involved in locating that information. With the explosive growth in digital and non-digital information, however, it has become increasingly difficult to find the time necessary to search for information

The potential for liquid biopsies in the precision medical treatment of breast cancer.

Currently the clinical management of breast cancer relies on relatively few prognostic/predictive clinical markers (estrogen receptor, progesterone receptor, HER2), based on primary tumor biology. Circulating biomarkers, such as circulating tumor DNA (ctDNA) or circulating tumor cells (CTCs) may enhance our treatment options by focusing on the very cells that are the direct precursors of distant metastatic disease, and probably inherently different than the primary tumor's biology. To shift the current clinical paradigm, assessing tumor biology in real time by molecularly profiling CTCs or ctDNA may serve to discover therapeutic targets, detect minimal residual disease and predict response to treatment. This review serves to elucidate the detection, characterization, and clinical application of CTCs and ctDNA with the goal of precision treatment of breast cancer

Tunnel Probabilistic Structural Analysis Using the FORM

In this paper tunnel probabilistic structural analysis (TuPSA) was performed using the first order reliability method (FORM). In TuPSA, a tunnel performance function is defined according to the boundary between the structural stability and instability. Then the performance function is transformed from original space into the standard normal variable space to obtain the design point, reliability index, and also the probability of tunnel failure. In this method, it is possible to consider the design factors as the dependent or independent random parameters with arbitrary probability distributions. A software code is developed to perform the tunnel probabilistic structural analysis (TuPSA) using the FORM. For validation and verification of TuPSA, a typical tunnel example with random joints orientations as well as mechanical properties has been studied. The results of TuPSA were compared with those obtained from Monte-Carlo simulation. The results show, in spite of deterministic analysis which indicates that the rock blocks are stable, that TuPSA resulted in key-blocks failure with certain probabilities. Comparison between probabilistic and deterministic analyses results indicates that probabilistic results, including the design point and probability of failure, are more rational than deterministic factor of safety

Resistance to Direct-Acting Antiviral Agents in Treatment of Hepatitis C Virus Infections

Compounds targeting nonstructural (NS) proteins of hepatitis C virus (HCV) demonstrate clinical promise, suggesting that NS3/NS4a, NS5A, or NS5B inhibitors are potential components in direct-acting antiviral (DAA) combination therapies. In vitro studies revealed dramatic inhibition of viral replication or alteration in subcellular localization of NS proteins. DAAs bind either to catalytic sites (NS3 and NS5B) or to domain-1 of NS5A. Although >90% of the patients clear HCV RNA from their sera, a significant portion of cirrhotic patients suffer from resistance or virological relapse. Mutations in specific residues (Q80K) in NS3 (M28, A30, L31, and Y93 in genotypes 1a and 1b or L28, L30, M31, and Y93 in genotype 4) in NS5A and A282T in NS5B are associated with resistance to DAA [resistance-associated variants (RAVs)]. Current knowledge on the NS functions, mode of action of DAAs, and impacts of RAVs on treatment response are discussed. Not only mutations affecting the binding of DAAs to target proteins but also substitutions affecting the replication fitness of mutant quasispecies are major determinants of treatment failures. These resistance-associated substitutions (RASs) are now considered the major viral mutants that influence the virological outcome after DAA treatment