Statistical Average Values Research Articles

Distribution of the DC-potential level in the brain of older women in the circumpolar region

The distribution of the direct current (DC) potential level was investigated in the brain of 97 women aged 55–74 years and permanently living in the circumpolar region. The DC-potential distribution was analyzed by mapping the DC-potential values obtained using monopolar measurements. The distributional characteristics of the DC-potential level were compared with the average statistical reference values for the corresponding age group. The DC-potential level in 55-to 74-year old women of the North was characterized by specific features, such as the smoothing of interhemispheric asymmetry and higher total brain energy consumption, compared with the reference values for the majority of the brain regions.

Novel micro-rings of molybdenum disulfide (MoS2).

Recently, molybdenum disulfide (MoS(2)) has become a popular material due to its unique electrical and chemical properties, and its use as a potential substitute for graphene. Herein, we report a new two-step method by utilizing thermal evaporation-sulfurization to synthesize MoS(2) which possesses an innovative micro-ring structure. The average statistical values of the height, width and external diameter were 69 nm, 0.3 μm and 5.0 μm, respectively. Then the mechanism for the growth of such MoS(2) micro-rings was proposed. A device based on the MoS(2) micro-ring was prepared by electron beam lithography, and its electrical transport properties were determined at different temperatures.

Monte Carlo Simulation of the Echo Signals from Low-Flying Targets for Airborne Radar

A demonstrated hybrid method based on the combination of half-space physical optics method (PO), graphical-electromagnetic computing (GRECO), and Monte Carlo method on echo signals from low-flying targets based on actual environment for airborne radar is presented in this paper. The half-space physical optics method , combined with the graphical-electromagnetic computing (GRECO) method to eliminate the shadow regions quickly and rebuild the target automatically, is employed to calculate the radar cross section (RCS) of the conductive targets in half space fast and accurately. The direct echo is computed based on the radar equation. The reflected paths from sea or ground surface cause multipath effects. In order to accurately obtain the echo signals, the phase factors are modified for fluctuations in multipath, and the statistical average value of the echo signals is obtained using the Monte Carlo method. A typical simulation is performed, and the numerical results show the accuracy of the proposed method.

Angle of repose of landslide debris deposits induced by 2008 Sichuan Earthquake

The angle of repose is defined to be the angle made by the heap of the granular deposited materials in the slope or the run-out of the deposits. Present study focuses on the angle of repose of landslide debris deposits induced by the 2008 Sichuan Earthquake in China. The angle of repose was measured in the field and tested in laboratory, respectively. The angles of repose of 87 landslide debris deposits along the left bank of the Minjiang River from Yingxiu to Wenchuan County (that is the location of the earthquake's epicenter) in Sichuan Province, China, were measured based on the laser measurement device. The range of the measured angles was 28.8° to 44.7°, with the statistical arithmetic average value 35.5°. The angle of repose was also tested in laboratory by using a very simple manual test. The value of the angle of repose obtained in laboratory is larger than that in the field. Also investigated are the factors influencing the angle of repose, including the relative compaction, particle size, and non-uniformity.

Service provided by fading MIMO channels: a deterministic perspective

ABSTRACTIn this paper, we study the channel service process of a multiple‐input multiple‐output (MIMO) system over an independent and identically distributed (i.i.d.) fading channel. One key problem of communication over fading MIMO channels is what kind of service the MIMO channel can provide. In this paper, this problem is investigated in terms of channel service process. Assuming that the channel state information is available at the receiver, the channel service process S(t) is defined as the integral of the instantaneous channel capacity over a time interval of length t, which specifies the service provided by the channel during the period. Using the characteristic function approach and the infinitely divisible law, it is proved that the channel service process S(t) is a deterministic linear function of time t, other than any curve form or a stochastic process. Specifically, , where is a constant equal to the corresponding ergodic capacity. This result has two implications: (i) i.i.d. fading MIMO channels can support a constant rate traffic stream of rate without higher layer transmission delay; (ii) the ergodic capacity is the actual transmission capacity of the fading channel, other than only a statistical average value. Copyright © 2012 John Wiley & Sons, Ltd.

Statistical Analyses of Response Spectra on Medium-Stiff Soil Site

The analyses on the statistical response spectra have an important role in determining the earthquake demand. Elastic and inelastic spectra on acceleration of the 205 records on medium-stiff soil site for SDOF systems are presented in statistical analyses. The empirical probability distributions of the spectral values are derived according to the Kolmogorov-Smirnov (KS) goodness-of-fit test. The formula for statistical average spectra of the ground motion ensemble are recommended, which are valuable for current research and code revisal. The results show that the statistical averaged elastic α spectra fits well to the design spectra prescribed in Chinese code when the period is smaller than 2s. The inelastic responses decrease with the increase of ductility demand μ when μ<4. The coefficients of variance of the elastic and inelastic spectra are still large and the dispersion cannot be ignored. The probabilistic distribution of the spectra value on acceleration is validated as the lognormal distributions. The proposed formulas give a good fit to the statistical average values.

Nanoscale mechanical behavior of vanadium doped ZnO piezoelectric nanofiber by nanoindentation technique

The nanoscale mechanical behavior of Zn0.975V0.025O (V-ZnO) piezoelectric nanofibers by electrospinning was investigated using a nanoindenter in detail. After being calcined at 700 °C, V-ZnO nanofibers are of hexagonal wurtzite phase crystal structure, and the diameter and length are in the range of 50–300 nm and several tens to several hundreds of micrometers. The statistical average values of reduced modulus and hardness are 58.7±4.2 and 3.3±0.2 GPa for the nanofibers, and they decrease by 47.2% and 34.0% in comparison with those of bulk ZnO. It indicates that size effect of the mechanical behavior was obviously observed for the nanofibers, and the mechanism is discussed in conjunction with their high surface-to-volume ratio. Indentation depth-dependent reduced modulus and hardness properties were observed at indentation depth less than 18 nm, and it is attributed to the strain gradient effect during nanoindentation.

A Lifting Wavelet Domain Audio Watermarking Algorithm Based on the Statistical Characteristics of Sub-Band Coefficients

In this paper, a new lifting wavelet domain audio watermarking algorithm based on the statistical characteristics of sub-band coefficients is proposed. First of all, an original audio signal was segmented and each segment was divided into two sections. Then, the Barker code was used for synchronization, the LWT (lifting wavelet transform) was performed on each section, a synchronization code and a watermark were embedded into the first section and the second section, respectively, by modifying the statistical average value of the sub-band coefficients. The embed strength was determined adaptively according to the auditory masking property. Experiments show that the embedded watermark has better robustness against common signal processing attacks than present algorithms based on LWT and can resist random cropping in particular.

Conservative Design Rainfall Distribution

To design urban storm water infrastructures, hydrologists apply the SCS Types I, II, and III 24-h rainfall distribution curves to simulate the design rainfall hyetographs by which storm runoff can be predicted accordingly. Although SCS 24-h rainfall curves are recommended by the Natural Resources Conservation Service and have been widely adopted for many cosmopolitan areas in the United States, it is not enough to understand how these curves compare with observed data. In this study, a 57-year hourly rainfall data recorded in Denver was analyzed and then compared with the SCS 24-h rainfall curves. It is concluded that these SCS 24-h Types I and II curves do not represent the statistical average values. Rather, they represent the worst time distribution to form a severe storm. Using the concept of enveloping curves, conservative rainfall distributions can be derived using a similar approach as revealed by the SCS 24-h curves. The approach suggested in this study requires much less rainfall data than the statistical average.

Tracking performance and average error analysis of GPS discriminators in multipath

Signal multipath in GPS leads to undesirable tracking errors and inaccurate ranging information. The extent of the tracking error in compromising the receiver performance depends on the multipath amplitude, delay, and phase relative to the direct path. The coherent discriminator and the noncoherent early-minus-late power discriminator offer different tracking accuracy and sensitivity to multipath parameters. In this paper, we develop analyses of the effect of multipath carrier phase offset on GPS tracking error bounds as well as statistical average error values. Although the two receiver discriminators share the same performance bounds, they differ in their response to the multipath within these bounds. The analytical expressions for this response provide the framework to assess the average performance of the two discriminators over the multipath phase distribution and other important propagation channel variables.

Elastic Incoherent Neutron Scattering on Systems of Biophysical Interest: Mean Square Displacement Evaluation from Self-Distribution Function

In the present work an operational recipe for the mean square displacement (MSD) determination, highlighting the connection between the self-distribution function and average statistical values, is presented. The determination of the MSD and of its contributions associated with different mechanisms, together with their thermal behavior, is performed by evaluating the self-distribution function derived by elastic incoherent neutron scattering (EINS). The approach is tested on EINS data collected by the backscattering spectrometer IN13 (ILL, Grenoble, France) on two model systems such as dry myoglobin in trehalose and poly(ethylene glycol) with mean molecular weight M(w) = 400 (PEG 400).

Cholesterol Exchange, DNA Damages, Apoptosis and Necrosis of Blood Cells in Severe Concomitant Injury

Objective: to study a number of free-radical reactions, the parameters of cholesterol exchange, and the extent of blood cell DNA damages in victims early after concomitant injury. Subjects and methods. The study covered 77 patients who had experienced severe mechanical injury. The patients’ condition on admission was an APACHE II of 19.1±5.4 scores. According to the outcome of the disease, all the patients were divided into 2 groups: 1) deceased patients and 2) survivors. The study was conducted on admission to an intensive care unit and on days 3, 5, 7, and 15. The extent of blood cell DNA damages and the proportion of apoptotic and necrotic blood cells were estimated by gel isolated cell elec-trophoresis (DNA rocket electrophoresis). The «Human 8-oxoGuanine DNA Glycosylate (OGG1) FLARE Assay» kit was used to measure the content of 8-hydroxy-2-deoxyguanosine in cell DNA. The cholesterol and overall antioxida-tive statuses and biochemical parameters were determined on an automatic biochemical Cobas Miras Plus analyzer. Very low-density lipoproteins (VLDL) and low-density lipoproteins (LDL) were calculated. Results and discussion. In severe concomitant injury, there were increases in DNA damages in the blood cells and in their apoptotic and necrotic processes, which were particularly pronounced on days 3—5. In the group of deceased patients, the increase of 8-hydroxy-2-deoxyguanosine was greater than the normal values on days 5 and 7. On admission, the systemic antioxidative status was greater than the normal values in the survivors and deceased patients and tended to diminish in both groups during an observation. The average statistical values of total cholesterol were lower at all stages of the study. At the stages of the study, the concentration of triglycerides and VLDL were in the normal range in all the patients. At week 1 of the observation, the level of LDL was normal or greater in the survivors than in the deceased. The changes in high-density lipoproteins were characterized by their decreased plasma levels throughout the observation of the victims. In both groups, the activity of alkaline phosphatase increased over time and was 1.5—2 times higher than the normal values on days 15. In the survivors, the admission activity of y-glutamyltransferase (y-GT) was in the normal range. The activity of the enzyme in this group tended to increase, so did the plasma level of total protein in these patients. Conclusion. In severe concomitant injury, there is an increase in DNA damage processes, which is associated with the enhanced cell death. The time course of changes in the levels of total cholesterol, LDL cholesterol, and total protein and in the activities of y-GT and 8-hydroxy-2-deoxyguanosine may be used as predictors. Key words: apoptosis, necrosis, DNA damage, 8-hydroxy-2-deoxyguanosine, cholesterol exchange, injury.

Constraining interacting dark energy models with flux destabilization

A destabilization in the transfer energy flux from the vacuum to radiation, for two vacuum decay laws relevant to the dark energy problem, is analyzed using the Landau–Lifshitz fluctuation hydrodynamic theory. Assuming thermal (or near thermal) equilibrium between the vacuum and radiation, at the earliest epoch of the Universe expansion, we show that the law due to renormalization-group running of the cosmological constant term, with parameters chosen not to spoil the primordial nucleosynthesis scenario, does soon drive the flux to fluctuate beyond its statistical average value thereby distorting the cosmic background radiation spectrum beyond observational limits. While the law coming from the saturated holographic dark energy does not lead the flux to wildly fluctuate, a more realistic non-saturated form shows again such anomalous behavior.

드래프트 관이 장착된 교반기 내의 유동 및 혼합특성 연구

Because the mixing efficiency is influenced remarkably by varying the geometrical configurations, the study of flow characteristics inside the mechanical agitator is very important to improve the performances. The draught tube in the agitator makes intermixing between the screw and tube by interrupting radial flow, and it makes circulation region in a mixing chamber. In general, the helical screw agitator with a draught tube (HSA) is proved more efficient to mix than the others. Consequently, such as the shapes of helical screw, number of pitches and the variation of angular velocity are the main parameters for improving the capacity of HSA. And also the suspension of the solid particles in the agitator can be determined these parameters. The rate of solids suspension in the mixing chamber was quantified with a statistical average value, o2. Numerical analyses were carried out, using a commercial CFD code, Fluent, to obtain the velocity, pressure and particle distributions under steady, laminar flow and no-slip conditions. Results are graphically depicted with various parameters.

Effects of phase distribution and grain size on the effective anisotropy and coercivity of nanocomposite Nd2Fe14B∕α-Fe magnets

The effects of phase distribution and grain size on the effective anisotropy and coercivity of the exchange-coupled nanocomposite permanent materials have been investigated in this paper. The effective anisotropy of nanocomposite permanent materials is supposed to be equal to the statistical average value of the anisotropy of magnetically soft and hard grains. The dependence of coercivity on grain sizes is mainly determined by the effective anisotropy of the grains. The calculated results show that, when the grain sizes of the soft and hard phases are identical and the volume fraction of the hard phase is given, the coercivity decreases with the reduction of the grain size. For the given size of the soft grains and the volume fraction of the hard phase, the coercivity shows a peak value as a function of the hard-grain size. The experimental enhancement of the coercivity with reducing grain size is attributed not to only the exchange-coupling interactions but also to the phase distribution.

GENERALIZATION OF CLASSICAL STATISTICAL MECHANICS TO QUANTUM MECHANICS AND STABLE PROPERTY OF CONDENSED MATTER

Classical statistical average values are generally generalized to average values of quantum mechanics. It is discovered that quantum mechanics is a direct generalization of classical statistical mechanics, and we generally deduce both a new general continuous eigenvalue equation and a general discrete eigenvalue equation in quantum mechanics, and discover that a eigenvalue of quantum mechanics is just an extreme value of an operator in possibility distribution, the eigenvalue f is just classical observable quantity. A general classical statistical uncertain relation is further given, and the general classical statistical uncertain relation is generally generalized to the quantum uncertainty principle; the two lost conditions in classical uncertain relation and quantum uncertainty principle, respectively, are found. We generally expound the relations among the uncertainty principle, singularity and condensed matter stability, discover that the quantum uncertainty principle prevents the appearance of singularity of the electromagnetic potential between nucleus and electrons, and give the failure conditions of the quantum uncertainty principle. Finally, we discover that the classical limit of quantum mechanics is classical statistical mechanics, the classical statistical mechanics may further be degenerated to classical mechanics and we discover that merely stating that the classical limit of quantum mechanics is classical mechanics is a mistake. As application examples, we deduce both the Schrödinger equation and the state superposition principle, and deduce that there exists a decoherent factor from a general mathematical representation of the state superposition principle; the consistent difficulty between statistical interpretation of quantum mechanics and determinant property of classical mechanics is overcome.

Studies of Rigid Rotor-Rigid Surface Scattering in Dynamical Lie Algebraic Method**The project supported by Natural Science Foundation of Shandong Province of China and National Natural Science Foundation of China and the Doctor Foundation of the Ministry of Education of China

The dynamical Lie algebraic method is used for the description of statistical mechanics of rotationally inelastic molecule-surface scattering. It can give the time-evolution operators about the low power of and by solving a set of coupled nonlinear differential equations. For considering the contribution of the high power of and , we use the Magnus formula. Thus, with the time-evolution operators we can get the statistical average values of the measurable quantities in terms of the density operator formalism in statistical mechanics. The method is applied to the scattering of (rigid rotor) by a flat, rigid surface to illustrate its general procedure. The results demonstrate that the method is useful for describing the statistical dynamics of gas-surface scattering.

The sequential Monte Carlo-quantum mechanics methodology. Application to the solvent effects in the Stokes shift of acetone in water

The sequential Monte Carlo quantum mechanics methodology is used to obtain the solvent effects on the Stokes shift of acetone in water. One of the great advantages of this methodology is that all the important statistical information is known before running into the costly quantum mechanical calculations. This advantage is discussed not only with respect to the statistical correlation between the different structures generated by the simulation but also in the proper identification of hydrogen bonds in liquids. To obtain the solvent effects in the Stokes shift of the n–π ∗ absorption transition of acetone in water, quantum-mechanical calculations are performed in super-molecular structures generated by NVT Monte Carlo simulation. The statistical correlation between configurations is analyzed using the auto-correlation function of the energy. The largest calculations include one acetone and 170 water molecules. One-hundred INDO/CIS super-molecular calculations are performed for each solvation shell to obtain the statistical average value. The calculated solvatochromic shift of the n–π ∗ absorption transition of acetone in water, compared to gas phase, is ∼1310 cm −1 in good agreement with the experimental blue shift of 1500±200 cm −1. For the emission of the relaxed excited state, the calculated shift is ∼1850 cm −1. The total calculated solvent effect on the Stokes shift of acetone in aqueous solution is thus 540 cm −1. A detailed analysis of the sampling of the configurations obtained in the Monte Carlo simulation is made and it is shown that all results represent statistically converged values.

A dynamical Lie algebraic approach to the second order polarizability of the substituted benzenes

The dynamical Lie algebraic (DLA) method is used to study the second-order nonlinear optical properties of substituted benzene molecules. In this formulation a dynamical Lie algebra is generated for the Pariser–Parr–Pople π-electron Hamiltonian of the molecule, and the time evolution operator is then given in terms of the group parameters. The group parameters can be determined by solving a set of coupled nonlinear differential equations. Thus, statistical average values of the dipole moment of the molecule are obtained in terms of the density operator formalism in statistical mechanics. The method is applied to the calculation of the second order polarizability of the para-disubstituted benzene molecules. Comparison with other quantum calculations is made. The results demonstrate that DLA method appears to provide an effective means for calculating the second-order nonlinear optical properties of certain classes of conjugated organic molecules.

A New Approach to Controlled Natural Ventilation of Livestock Buildings

An alternative is considered for substitution of the present mechanically ventilated air-conditioning systems in standard livestock building structures on commercial pig-growing farms in Bulgaria. On the basis of a proposed method of controlled natural ventilation and air conditioning in a stock breeding building, some pig-breeding buildings for piglets and fattened pigs have been restructured. Seasonal studies of temperature and humidity have been conducted. Average statistical values for the air temperature and humidity in the restructured buildings and in the existing building with mechanical ventilation, which is regarded as reference, are presented. In the naturally ventilated building, a more favourable humid environment is maintained, the temperatures being comparable to those in the reference house. The regained heat flows of the heat exchange system have been calculated. A 28.25% degree of heat recovery of the ventilation heat loss can be obtained. The favourable results with the naturally ventilated systems show that this system is a realistic alternative for ventilation in pig-breeding buildings in Bulgaria and its application must be promoted.