Weak Dependence

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Weak Dependence on Initialization in Mixture of Linear Regressions

Weak Dependence on Initialization in Mixture of Linear Regressions

Abstract—This paper examined how initial values of a learning algorithm influence the performance of mixture of linear regressions (MoLR). MoLR employs the EM algorithm as a learning algorithm. Our experiments used two kinds of artificial data and one real dataset. Experiments using artificial data showed MoLR discovered the original lines from data containing Gaussian or t-distribution noise. Moreover, almost all our experiments showed the best solution can be easily found with any initialization method. This suggests MoLR may have rather weak dependence on initialization.

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A Tight Prediction Interval for False Discovery Proportion under Dependence

A Tight Prediction Interval for False Discovery Proportion under Dependence

The false discovery proportion (FDP) is a useful measure of abundance of false positives when a large number of hy- potheses are being tested simultaneously. Methods for controlling the expected value of the FDP, namely the false dis- covery rate (FDR), have become widely used. It is highly desired to have an accurate prediction interval for the FDP in such applications. Some degree of dependence among test statistics exists in almost all applications involving multiple testing. Methods for constructing tight prediction intervals for the FDP that take account of dependence among test sta- tistics are of great practical importance. This paper derives a formula for the variance of the FDP and uses it to obtain an upper prediction interval for the FDP, under some semi-parametric assumptions on dependence among test statistics. Simulation studies indicate that the proposed formula-based prediction interval has good coverage probability under commonly assumed weak dependence. The prediction interval is generally more accurate than those obtained from ex- isting methods. In addition, a permutation-based upper prediction interval for the FDP is provided, which can be useful when dependence is strong and the number of tests is not too large. The proposed prediction intervals are illustrated using a prostate cancer dataset.
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Interface limited hole extraction from methylammonium lead iodide films

Interface limited hole extraction from methylammonium lead iodide films

from B10 5 to 2.7 cm 2 s 1 spanning five orders of magnitude. 6 This can be partly explained by different material properties of the same stoichiometry perovskites depending on the synthe- sis, deposition method, post processing and substrate choice, but in addition different measurement techniques and experi- ment conditions can give different results. Transient grating technique has revealed weak dependence of the ambipolar carrier diffusion coefficient on carrier density in perovskites of high compositional quality whilst other films showed very strong dependence on carrier density which was attributed to trap filling. 7 Another recent study has shown indications of different lattice reorganizations around excitons and charges in hybrid perovskites which are very likely to affect exciton and charge localization and transport. 8 Here we show carrier
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Interannual variability of winter precipitation in the European Alps: relations with the North Atlantic Oscillation

Interannual variability of winter precipitation in the European Alps: relations with the North Atlantic Oscillation

Overall, this study shows that the Alps are a rather sin- gular climatic region in Europe, which exhibits precipitation regimes with two major distinctive features: 1) a particularly high interannual variability of winter precipitation, and 2) a weak dependence on the North Atlantic Oscillation and a slightly better association with the East Atlantic West Russia for the first part of the winter. The relatively strong variability of winter precipitation in the Alps seems to be endogenous to this region, possibly resulting by the complex interactions between climatic forcings and topography. Due to the impor- tance of winter precipitation for the sustainability of alpine very diverse water uses that rely on snow accumulation and melting, the findings of this study deserve additional investi- gations. The challenge of dealing with uncertainties of rain- fall measurements in mountains would make this research even more appealing.
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Magnetic Properties of Cluster Glassy Ni/NiO Core–Shell Nanoparticles: an Investigation of Their Static and Dynamic Magnetization

Magnetic Properties of Cluster Glassy Ni/NiO Core–Shell Nanoparticles: an Investigation of Their Static and Dynamic Magnetization

AFM/FM core–shell nanocrystal system [14], they will interact magnetically via two mechanisms: the induce- ment of magnetic exchange across particle boundaries between particles in contact or dipolar interaction (DI) between the particles. The exchange inter-particle inter- action can give rise to the anomalous spin rotation of the agglomerated particles [15]. While a fair understand- ing of the mechanism underlying the field cooling magnetization process and enhanced exchange bias has been achieved in the case of diluted nanocrystals, many experimental results for interacting assemblies remain unexplained. To analyze and eventually understand the experimental results obtained for the static and dynamic properties of interacting or noninteracting nanoparticles, remanent magnetization measurements were used to investigate the enhancement of the exchange bias in core–shell nanocrystals in this work. We studied the size dependence of the conventional exchange bias and anisotropic energy between the Ni-core and NiO-shell nanoparticles. The shell grew at the expense of the Ni- core, forming a passivating layer of NiO, as confirmed and estimated by the X-ray absorption near-edge structure (XANES) measurements. The conventional exchange bias (CEB) effect observed in the system after the process of field cooling through the Neel temperature was attributed to FM unidirectional anisotropy that formed at the inter- face between the FM-core and AFM-shell. Cooling field mapping for the study of the dipole–dipole interaction was performed by measuring the remanent magnetization at 2 K, revealing a weak dependence of the dipolar inter- action on the cooling field which gives rise to the multiple anisotropic barriers observed during the cluster glassy behavior.
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Electron Cyclotron Heating Start-Up Experiments on TST-2

Electron Cyclotron Heating Start-Up Experiments on TST-2

Experiments were performed to study non-inductive current generation by electron cyclotron heating (ECH) in the TST-2 spherical tokamak. A magnetron (2.45 GHz / 5 kW) and a horn antenna were used to inject either the O- or X-mode. The maximum plasma current does not depend on the injected wave polarization; however, it has a weak dependence on the vertical field configuration and is proportional to the vertical field. The initial current ramp-up rate depends on various operational parameters. The ramp-up rate increases with the injected EC wave power, and decreases with the filling pressure, resonance position (i.e., the toroidal field strength), and vertical field strength. It also depends on the magnetic field configuration. Conversely, the ramp-up rate does not depend on wave polarization, suggesting that multiple pass absorption of the EC wave is important.
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Role of the Hoyle state in the 12C+12C fusion at low energies

Role of the Hoyle state in the 12C+12C fusion at low energies

Our calculation is free of parameters, except for a weak dependence on the absorption potential. It provides a simultaneous description of elastic scattering and of fusion. Elastic cross sections around the Coulomb barrier are well known experimentally [23] and will serve as a test of the model, in order to assess the accuracy of the less known fusion cross section. The main results are presented in Ref.[24], and we refer to that reference for detail.

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Weak localization and weak antilocalization in doped germanium epilayers

Weak localization and weak antilocalization in doped germanium epilayers

(Received 12 December 2016; accepted 23 January 2017; published online 7 February 2017) The magnetoresistance of 50 nm thick epilayers of doped germanium is measured at a range of temperatures down to 1.6 K. Both n- and p-type devices show quantum corrections to the conduc- tivity in an applied magnetic field, with n-type devices displaying weak localization and p-type devices showing weak antilocalization. From fits to these data using the Hikami-Larkin-Nagaoka model, the phase coherence length of each device is extracted, as well as the spin diffusion length of the p-type device. We obtain phase coherence lengths as large as 325 nm in the highly doped n-type device, presenting possible applications in quantum technologies. The decay of the phase coherence length with temperature is found to obey the same power law of l / / T c , where
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Thermal Contraction of Electrodeposited Bi/BiSb Superlattice Nanowires

Thermal Contraction of Electrodeposited Bi/BiSb Superlattice Nanowires

compared with the other samples. The temperature dependence of the a for SL1 is also relatively weak, but has a similar shape with other three samples, see Fig. 3b. The thermal expansion coefficient of the Bi/BiSb SLNWs with different bilayer thicknesses are different at different temperatures, but all have a negative value at the whole measuring temperature, and firstly increases with temper- ature, after reaches an extreme, then slightly decreases and finally increases till nearly zero. The negative thermal expansion coefficient indicates a thermal contraction effect, which is in accordance with the decrease of the lattice parameter. This result also indicates that the thermal expansion of AAM has no contribution to the nanowire expansion based on Poisson’s effect [36]. The increased a is mainly attributed to the partly elimination of the defect and stress at elevated temperature, as the elimination of stress is predominant at low temperature, while that of defects becomes predominant at high temperature. The defect and stress come from not only the bulk and the surface of the segment Bi and BiSb nanowires, but the interface of the SLNWs as well. The obvious different temperature Fig. 1 Top view (a) and side
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Assessment of tree layer biomass and structure using aerial photos in lake catchments of the Šumava Mts

Assessment of tree layer biomass and structure using aerial photos in lake catchments of the Šumava Mts

ABSTRACT: The combination of georeferenced colour aerial photos and limited field measurements of individual trees was used to determine tree stand biomass in forests of prevailing Norway spruce. The technique was carried out in two localities – small catchments of natural lakes in the Bohemian Forest (56 and 76 ha in size, respectively). This method is not so expansive as the inventory based on sample plots, namely in the terrain of high dynamics in the mountains. Tree crown diameters were determined semi-automatically on the basis of orthophotos. The catchment of Plešné jezero Lake can be described by these average values: crown diameter 4.5 ± 1.35 m, mean tree height varying between 19.6 and 30.2 m depending on altitude (tree average and standard deviation are 25.5 ± 3.9 m), tree density 154 ± 67.7 ha and stand biomass 197 t/ha. The Čertovo jezero Lake catchment shows somewhat different values: crown diameter 4.9 ± 1.35 m, mean tree height varying between 20.9 and 25.1 m (dependence on altitude is weak; tree average and standard devia- tion are 25.6 ± 2.0 m), tree density 200 ± 65.7 ha (all parameters for Norway spruce only), and stand biomass 156 t/ha (Norway spruce) + 17 t/ha (European beech). Some features are common to both catchments: a regular to random tree pattern prevails. Tree clumping is typical of the most extreme stands. Minimum tree density occurs in the zone of the altitudes 1,200–1,250 m a.s.l. The crown diameter to dbh ratio is independent of altitude. Tree height decreases linearly with altitude. The distribution of trees according to crown diameter is skewed to higher values.
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Allosteric interactions governing oxygen equilibria in the haemoglobin system of the spiny dogfish, Squalus acanthias

Allosteric interactions governing oxygen equilibria in the haemoglobin system of the spiny dogfish, Squalus acanthias

O2 affinity and its dependence on protons, organic phosphates, urea and temperature The stripped Hb showed a high O2 affinity, a weak Bohr effect at 10°C and pH 7-85, 7*50 = 2-3 and 0 = [r]

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The electrochemical deposition of mercury on glassy carbon electrodes : a thesis in partial fulfilment of the requirements for the degree of Masters in Science in Chemistry at Massey University, Palmerston North, New Zealand

The electrochemical deposition of mercury on glassy carbon electrodes : a thesis in partial fulfilment of the requirements for the degree of Masters in Science in Chemistry at Massey University, Palmerston North, New Zealand

A range of experiments were undertaken including concentration dependence, rotation dependence, scan rate dependence, electrochemical-cleaning, and the dependence of the length of time l[r]

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Dependence of GAMA galaxy halo masses on the cosmic web environment from 100 deg2 of KiDS weak lensing data

Dependence of GAMA galaxy halo masses on the cosmic web environment from 100 deg2 of KiDS weak lensing data

Section 3.2), and found the distribution in local density of galaxies in each cosmic environment. From these local density distributions they concluded that galaxies in denser cosmic environments (e.g. knots) tend to have higher local densities as well. The correlation between large-scale density and the local abundance of haloes com- plicates observational tests of the predicted tidal effects on galaxy properties. In order to separate the effects of local density from those of the cosmic web, E15 used a ‘shuffling’ method (see Section 3.3). By creating four new galaxy samples which retain the local density distribution from the original cosmic environments, but with the galaxies shuffled between the cosmic environments, they erased the information from the cosmic environment classification while re- taining the information on local density. By comparing the galaxies in these ‘shuffled environments’ to those in the true cosmic envi- ronments, they were able to eliminate the dependence on the local overdensity of their measurement of the galaxy LF. In this work we use the environment classification from E15, and follow their shuffling method in order to extract the effect on halo mass from the cosmic environment alone, without effects from the local density. As explained in Section 3.2 we use 4 h −1 Mpc radii to measure the local density, instead of the 8 h − 1 Mpc used in E15. This might com-
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On a weak form of weak quasi continuity

On a weak form of weak quasi continuity

1. Introduction. Weakly quasi-continuous functions were introduced by Popa and Stan [9]. Recently, weak quasi-continuity has been developed further by Noiri [5, 6] and Park and Ha [8]. Due to a result by Noiri [5], weak quasi-continuity is equiva- lent to the weak semicontinuity developed by Arya and Bhamini [1]. The purpose of this note is to introduce the concept of subweak quasi-continuity, which we define in terms of a base for the topology on the codomain. We establish that this condition is strictly weaker than weak quasi-continuity and we use it to strengthen some of the results in the literature concerning weak quasi-continuity. For example, we show that the graph of a subweakly quasi-continuous function with a Hausdorff codomain is semiclosed. We also show that, if the graph function is subweakly quasi-continuous with respect to the usual base for the product space, then the function itself is weakly quasi-continuous, and that, if a function is subweakly quasi-continuous with respect to the base Ꮾ , then the restriction to a preopen set is subweakly quasi-continuous with respect to the same base. These results strengthen slightly the comparable re- sults for weakly quasi-continuous functions. Finally, we extend a result concerning weakly quasi-continuous retractions and investigate some of the basic properties of subweakly quasi-continuous functions.
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Weak and $(-1)$-weak amenability of second dual of Banach algebras

Weak and $(-1)$-weak amenability of second dual of Banach algebras

{0}. In this paper we prove some important properties of this notion, for instance if A 00 is (−1)- weakly amenable then A is essential and there is no non-zero point derivation on A. We also give some examples, namely, the second dual of every C ∗ -algebras is (−1)-weakly amenable. Finally, we study the relationships between the (−1)-weakly amenability of A 00 and the weak amenability of A 00 or A.

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Aging in language dynamics

Aging in language dynamics

a rapid growth due to the pressure of discrimination (for a detailed description of CG we refer to the Materials and Methods section), followed by a rapid drop due to the onset of consensus and the merging of perceptual categories. A second regime is characterized by a quasi-arrested dynamics signaled by a “plateau” region, corresponding to a value of the average number of linguistic categories of the order of ten [21, 22]. Interestingly, the dependence of the number of linguistic categories on the population size N is different in the two regimes. In the first one, the average number of linguistic categories scales with log N (see inset of fig. 2a), while in the second regime the dependence of the height of the plateau on the population size is extremely weak (O( p log log (N ))): the average number of linguistic categories in the population remains limited to a small value (of the order of 20 ± 10) even for very large population sizes (up to billions of individuals). Furthermore, in the first regime we recover a time dependence on the population size of order N 3/2 (fig. 2a), with a similar behaviour as in the Naming Game [34, 35], while the length of the plateau features a much stronger dependence on N, reaching a practically infinite value for large populations. At very large times, when the population is finite, the average number of linguistic categories starts to drop. We shall come back to this finite-size effect later on in the article. Most importantly, at the onset of the plateau region we observe a slowing down of the dynamics signaled by the divergence of the persistence time (fig. 2b). The plateau region is thus the interesting regime describing the persistence and evolution of the category system, and we will next describe its properties by looking at a more sophisticated dynamical quantity.
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Spin-orbit interaction in InAs/GaSb heterostructures quantified by weak antilocalization

Spin-orbit interaction in InAs/GaSb heterostructures quantified by weak antilocalization

Here we show, through magnetotransport weak antilocal- ization (WAL) measurements of the temperature and gate dependence of the relevant scattering length scales, that the dominant underlying spin-relaxation mechanism in our InAs/GaSb heterostructure is EY, and not DP in the form of the Rashba SOI owing to structural inversion symmetry, as previously suggested [22–24,26]. We do this by demonstrating that the length for spin relaxation may be tuned using an electrostatic gate controlling the mean-free path. Finally, we report our results obtained from an InAs QW, which also shows strong indicators for the EY mechanism.
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Identification of Serpulina species associated with porcine colitis by biochemical analysis and PCR

Identification of Serpulina species associated with porcine colitis by biochemical analysis and PCR

Results of biochemical tests and a group IV PCR assay performed on Scottish field strains of Serpulina isolated from pigs with colitis Strain.. Strong Strong Weak Weak Weak Weak Weak Wea[r]

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Crossover from weak localization to weak antilocalization in a disordered microbridge

Crossover from weak localization to weak antilocalization in a disordered microbridge

In Fig. 2, we show results of a numerical solution of ␦ g for the examples s(x) constant, s(x) ⫽ 1 ⫹ 4 兩 2x/L 兩 and s(x) ⫽ 1 ⫹ 4(2x/L) 2 , ⫺ L/2 ⬍ x ⬍ L/2. These functional forms correspond to diffusive microbridges in a two- dimensional electron gas of the form shown in the inset of Fig. 2 with uniform impurity concentration and mean free path l Ⰶ W. The three sets of curves in the figure represent strong, intermediate and weak spin-orbit scattering, respec- tively. For the intermediate case 共 middle set of curves in Fig. 2 兲 , three different values of l SO were chosen so that the
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On weak bi ideals in near subtraction Semigroup

On weak bi ideals in near subtraction Semigroup

near subtraction semigroup we establish weak bi- under necessary and sufficient condition. In this paper we shall introduce weak bi-ideal in near ubtraction semigroups and obtain equivalent conditions for ubtraction semigroups using quasi- ideals. This concept motivates the study of different kinds of new ideas in algebraic theory especially ideas in subtraction bialgebra and Fuzzy Prime ideal in semigroup and maximal

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