Different statistical procedures are differently sensitive to data rounding. It turns out that tests for exponentiality are more sensitive to the data rounding than many classical parametric tests or ...than nonparametric tests for normality. In this work we find out which exponentiality tests are more robust and which ones are less robust to the rounding. The main tool is Monte Carlo simulation. We estimate and compare the probability of Type I error of nineteen exponentiality tests for different rounding levels and different sample sizes.
A new high light yield liquid scintillator based on linear alkylbenzene (LAB) as an organic solvent and a novel nanostructured organosilicon liminophore as a scintillation fluor has been developed ...for the next generation large-scale experiments in astroparticle physics. It is shown that the developed liquid scintillator has light yield almost two times higher than traditional LAB-based liquid scintillator with PPO fluor, when peak light yield values are compared, since the former peaks at 490 nm, while the latter peaks at 360 nm. At the same time light emission kinetics is characterized by about 10 ns decay time constant for its fastest component which contributes more than 80% to the total light yield of the scintillator.
The previously developed procedures for preparing dihydrodicyclopentadiene (DHDCPD) and tetrahydrodicyclopentadiene (THDCPD) are considered comprehensively. The performance of traditional ...dicyclopentadiene (DCPD) hydrogenation catalysts (Raney Ni, Pd/C) is compared to that of catalysts based on Ni or Pd nanoparticles on a polymer matrix. Metal-containing catalytic systems showing the highest performance in selective (to obtain DHDCPD) and exhaustive (to obtain THDCPD) DCPD hydrogenation are considered. Analysis of the data published in the chemical literature and in patents allows the catalytic methods for selective hydrogenation of dicyclopentadiene using catalysts based on palladium (and, possibly, also nickel), developed in the past decade, to be recommended as the most promising catalysts for commercial use.
The range of applications for distributed fiber-optic sensors is constantly expanding due to both the growing needs of industry and the development of the measurement capabilities of the sensors ...themselves. In connection with the need to develop methods for interpreting sensor signals, it is extremely important to form sets of test signals for distributed fiber-optic sensors obtained under known conditions and effects on the fiber. In the presence of reliable analytical models of signals from distributed fiber-optic sensors, it is extremely convenient to obtain test signals in the course of numerical experiments. The paper will consider the processes of formation of backscattering signals in Rayleigh reflectometric systems and describe physical and mathematical models that allow calculations of signals under different operating conditions. Two approaches for calculating the resulting backscatter signal are proposed: (1) based on the temporal representation of the probing signal and the impulse response of the sensitive fiber and (2) an alternative approach based on the spectral representation of the probing signal and the transfer function of the fiber. The presented results can be used both for direct simulation of the operation of reflectometric systems using Rayleigh scattering and for the analysis of existing limitations and the specifics of their operation.
Since data for statistical analysis are always given in a discretized form, observations contain not only measurement errors but also rounding errors which are determined by the discretization step. ...In this paper we consider situations where the rounding errors are considerable: they are comparable to or even greater (in average) than the measurement errors. It is shown that it can be reasonable to increase the measurement errors in order to reduce the error of the final result.
The existing methods for synthesizing 2-vinylnorbornane were considered comprehensively. The efficiency and feasibility of two main synthetic routes to 2-vinylnorbornane, heterocodimerization of ...ethylene with norbornene and selective hydrogenation of 5-vinylnorborn-2-ene, were compared on the basis of the available papers and patent data.
Polymer nanocomposites based on Cu(Cu
2
O)-LDPE with a volume fraction of 0.1–0.4 copper filler in the form of spherical nanoparticles with sizes from 10 to 25 nm were synthesized. The electrical ...conductivity of such composite nanomaterials was measured, which is 4.5–5 times higher than the electrical conductivity of a polyethylene matrix. To predict the electrical conductivity of such materials, an analysis of well-known mathematical models is carried out and models for predicting the electrical conductivity of such materials are selected that are adequate to the experimental data.
In some areas of statistical analysis (e.g., biology, medicine),data is often available in a roughly rounded form and relatively large samples. Statistical procedures vary in their sensitivities of ...data rounding. Different criteria of normality control the probability of Type I errors in rounding data. It is found that criteria based on a sample’s moments are robust when it comes to rounding, while the criteria based on order statistics are unstable. The situation is opposite to contrasts the spike robustness where sample moments are more sensitive and less robust than the order statistics.
Some new characterizations of the exponential distribution in the class of distributions with monotone hazard rate are obtained. The characterizations are formulated in terms of expectations of order ...statistics.
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