Statistical characteristics of the mean level of an elite group utility in selection

2019 ◽  
pp. 57-64
Author(s):  
A. A. Monakov
Keyword(s):  
Error Probability ◽  
Social Systems ◽  
Group Development ◽  
Statistical Characteristics ◽  
High Status ◽  
Critical Probability ◽  
Utility Level ◽  
Selection Rules ◽  
Elite Group ◽  
The Mean

Introduction:The development of biological and social systems is largely determined by the utility level of the elite group which stands out from the main population, being characterized by a high status. An elite group development process is random due to unavoidable errors in selection. The degree of influence of these errors on the utility level of an elite group can differ depending on the selection rules.Purpose:Evaluation of the influence of selection rules on the dynamics of the mean level of an elite group utility.Results:We have studied the dynamically changing probabilistic characteristics of an average elite group utility level, following two different selection scenarios: with a fixed threshold, and with a threshold determined by the mean level of the group utility achieved by the moment of the selection. It has been found out that in the first scenario the mean level of the elite group utility tends to a level whose value, even when the selection error probability is high, is greater than the mean utility level for the whole population. However, if it is unacceptable to reduce the mean level of the elite utility below the selection threshold, the error probability should be less than or equal to the square of the probability that a population member is selected for the elite group. It is proved that in the second scenario the mean level of the elite group utility tends to the mean value of this parameter for the whole population, regardless of the selection error probability. The latter affects only the duration of the transition process during which the elite «dissolves» in the population and its representatives cease to differ on average from the other members of the population in terms of their utility. The concept of critical probability of selection errors is introduced, at which the mean level of the elite group utility is equal to the lowest permissible boundary.Practical relevance:It is proved that correct elite development requires a selection scenario with a fixed high threshold. The calculated value of the critical probability of selection errors can be used to control the development of an elite group.

scholarly journals Attitude and Heading Estimation for Indoor Positioning Based on the Adaptive Cubature Kalman Filter

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 79
Author(s):  
Jijun Geng ◽  
Linyuan Xia ◽  
Dongjin Wu
Keyword(s):  
Kalman Filter ◽  
Angular Rate ◽  
Indoor Positioning ◽  
Location Based Services ◽  
Statistical Characteristics ◽  
Fading Memory ◽  
Limited Memory ◽  
Cubature Kalman Filter ◽  
The Mean ◽  
Heading Estimation

The demands for indoor positioning in location-based services (LBS) and applications grow rapidly. It is beneficial for indoor positioning to combine attitude and heading information. Accurate attitude and heading estimation based on magnetic, angular rate, and gravity (MARG) sensors of micro-electro-mechanical systems (MEMS) has received increasing attention due to its high availability and independence. This paper proposes a quaternion-based adaptive cubature Kalman filter (ACKF) algorithm to estimate the attitude and heading based on smart phone-embedded MARG sensors. In this algorithm, the fading memory weighted method and the limited memory weighted method are used to adaptively correct the statistical characteristics of the nonlinear system and reduce the estimation bias of the filter. The latest step data is used as the memory window data of the limited memory weighted method. Moreover, for restraining the divergence, the filter innovation sequence is used to rectify the noise covariance measurements and system. Besides, an adaptive factor based on prediction residual construction is used to overcome the filter model error and the influence of abnormal disturbance. In the static test, compared with the Sage-Husa cubature Kalman filter (SHCKF), cubature Kalman filter (CKF), and extended Kalman filter (EKF), the mean absolute errors (MAE) of the heading pitch and roll calculated by the proposed algorithm decreased by 4–18%, 14–29%, and 61–77% respectively. In the dynamic test, compared with the above three filters, the MAE of the heading reduced by 1–8%, 2–18%, and 2–21%, and the mean of location errors decreased by 9–22%, 19–31%, and 32–54% respectively by using the proposed algorithm for three participants. Generally, the proposed algorithm can effectively improve the accuracy of heading. Moreover, it can also improve the accuracy of attitude under quasistatic conditions.

scholarly journals On the Performance Analysis of Switched Diversity Combining Receivers over Fisher–Snedecor ℱ Composite Fading Channels

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3014
Author(s):  
Weijun Cheng ◽  
Xiaoting Wang ◽  
Tengfei Ma ◽  
Gang Wang
Keyword(s):  
Fading Channels ◽  
Error Probability ◽  
Signal To Noise Ratio ◽  
Multipath Fading ◽  
Performance Criteria ◽  
Statistical Characteristics ◽  
Diversity Combining ◽  
Systematic Analysis ◽  
Average Bit Error Probability ◽  
Switched Diversity Combining

In some emerging wireless applications, such as wearable communication and low-power sensor network applications, wireless devices or nodes not only require simple physical implementation approaches but also require certain reliable receiver techniques to overcome the effects of multipath or shadowed fading. Switched diversity combining (SDC) systems could be a simple and promising solution to the above requirements. Recently, a Fisher–Snedecor ℱ composited fading model has gained much interest because of its modeling accuracy and calculation tractability. However, the performance of SDC systems over ℱ fading channels has not yet been analyzed in the open literature. To this end, this paper presents a systematic analysis of SDC systems over ℱ fading channels, including dual-branch switch-and-stay combining (SSC), multibranch switch-and examine combining (SEC), and SEC with post-examining selection (SECps) systems. We first investigate the statistical characteristics of univariate and bivariate ℱ distributions. Then, these statistical expressions are introduced into the above SDC systems and the statistical metrics of the output signal-to-noise ratio (SNR) for these systems are deduced in different ℱ fading scenarios. Thirdly, certain exact and novel expressions of performance criteria, such as the outage probability, the average bit error probability and average symbol error probability, as well as the average channel capacity for SSC, SEC, and SECps are derived. To find the optimum performance, optimal analysis is performed for the independent and identically distributed cases. Finally, numerical evaluation and simulations are carried out to demonstrate the validity of the theoretical analysis under various ℱ fading scenarios. According to the obtained results, the multipath fading parameter has more influence on the performance of SDC systems than the shadowing parameter, the correlation coefficient, or the average SNR. Importantly, the SDC systems can provide switched diversity gains only when the switching threshold is not too large or too small compared to the average SNR.

scholarly journals A Field Measurement Based Wind Characteristics Analysis of a Typhoon in Near-Ground Boundary Layer

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 873
Author(s):  
Dandan Xia ◽  
Liming Dai ◽  
Li Lin ◽  
Huaifeng Wang ◽  
Haitao Hu
Keyword(s):  
Turbulence Intensity ◽  
Field Measurement ◽  
Three Dimensional ◽  
Wind Data ◽  
Statistical Characteristics ◽  
Gust Factor ◽  
Characteristics Analysis ◽  
Wind Characteristics ◽  
The Mean ◽  
The Relationship

The field measurement was conducted to observe the wind field data of West Pacific typhoon “Maria” in this research. With the application of ultrasonic anemometers installed in different heights (10 m, 80 m, 100 m) of the tower, the three dimensional wind speed data of typhoon “Maria” was acquired. In addition, vane-type anemometers were installed to validate the accuracy of the wind data from ultrasonic anemometers. Wind characteristics such as the mean wind profile, turbulence intensity, integral length scale, and wind spectrum are studied in detail using the collected wind data. The relationship between the gust factor and turbulence intensity was also studied and compared with the existing literature to demonstrate the characteristics of Maria. The statistical characteristics of the turbulence intensity and gust factor are presented. The corresponding conclusion remarks are expected to provide a useful reference for designing wind-resistant buildings and structures.

scholarly journals Statistical Characteristics of Unsteady Storms in Radar Observations for the Beijing–Tianjin Region

2015 ◽  
Vol 54 (1) ◽  
pp. 106-116 ◽  
Author(s):  
Yu Wang ◽  
Hong-Qing Wang ◽  
Lei Han ◽  
Yin-Jing Lin ◽  
Yan Zhang
Keyword(s):  
Warm Season ◽  
Environmental Parameters ◽  
Statistical Characteristics ◽  
Movement Speed ◽  
Movement Direction ◽  
Upper Troposphere ◽  
Maximum Value ◽  
Dynamic Factors ◽  
The Mean ◽  
Wind Profiles

AbstractThis study was designed to provide basic information for the improvement of storm nowcasting. According to the mean direction deviation of storm movement, storms were classified into three types: 1) steady storms (S storms, extrapolated efficiently), 2) unsteady storms (U storms, extrapolated poorly), and 3) transitional storms (T storms). The U storms do not fit the linear extrapolation processes because of their unsteady movements. A 6-yr warm-season radar observation dataset was used to highlight and analyze the differences between U storms and S storms. The analysis included geometric features, dynamic factors, and environmental parameters. The results showed that storms with the following characteristics changed movement direction most easily in the Beijing–Tianjin region: 1) smaller storm area, 2) lower thickness (echo-top height minus base height), 3) lower movement speed, 4) weaker updrafts and the maximum value located in the mid- and upper troposphere, 5) storm-relative vertical wind profiles dominated by directional shear instead of speed shear, 6) lower relative humidity in the mid- and upper troposphere, and 7) higher surface evaporation and ground roughness.

The Reliability of Manuscript Evaluation for the South African Journal of Psychology

1993 ◽  
Vol 23 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Cornells Plug
Keyword(s):  
Peer Review ◽  
South African ◽  
Review Process ◽  
Peer Review Process ◽  
High Status ◽  
South African Journal ◽  
The South ◽  
Weighted Mean ◽  
The Mean ◽  
African Journal

The peer review process is widely used to evaluate manuscripts for publication in scientific journals. Yet the reliability of recommendations about the suitability of manuscripts has been found to be quite low: the weighted mean of the single-reviewer reliability for a variety of journals is only 0,29. This paper describes a study of the evaluation of manuscripts submitted to the South African Journal of Psychology (SAJP) from 1988 to 1990. Single-reviewer reliability was found to be 0,34, slightly (but not significantly) above the mean for high status overseas journals. An investigation of other aspects of the review process indicates that peer review is useful to both authors and editors despite its shortcomings. Most of the recommended improvements of peer review suggested recently were incorporated into the SAJP's review process several years ago.

Innovation approach to detect the faults in multidimensional dynamic systems

Kybernetes ◽  
2010 ◽  
Vol 39 (1) ◽  
pp. 127-139 ◽  
Author(s):  
Chingiz Hajiyev ◽  
Ali Okatan
Keyword(s):  
Kalman Filter ◽  
Real Time ◽  
Dynamic Systems ◽  
Detection Algorithm ◽  
Statistical Characteristics ◽  
Sensor Faults ◽  
Content Type ◽  
Longitudinal Dynamics ◽  
Mean And Variance ◽  
The Mean

PurposeThe purpose of this paper is to design the fault detection algorithm for multidimensional dynamic systems using a new approach for checking the statistical characteristics of Kalman filter innovation sequence.Design/methodology/approachThe proposed approach is based on given statistics for the mathematical expectation of the spectral norm of the normalized innovation matrix of the Kalman filter.FindingsThe longitudinal dynamics of an aircraft as an example is considered, and detection of various sensor faults affecting the mean and variance of the innovation sequence is examined.Research limitations/implicationsA real‐time detection of sensor faults affecting the mean and variance of the innovation sequence, applied to the linearized aircraft longitudinal dynamics, is examined. The non‐linear longitudinal dynamics model of an aircraft is linearized. Faults affecting the covariances of the innovation sequence are not considered in the paper.Originality/valueThe proposed approach permits simultaneous real‐time checking of the expected value and the variance of the innovation sequence and does not need a priori information about statistical characteristics of this sequence in the failure case.

Mean-Square Response of Thermoviscoelastic Medium to Nonstationary Random Excitation

1976 ◽  
Vol 43 (1) ◽  
pp. 150-158 ◽  
Author(s):  
W. Mosberg ◽  
M. Yildiz
Keyword(s):  
Random Excitation ◽  
Irreversible Thermodynamics ◽  
Envelope Function ◽  
Statistical Characteristics ◽  
Mean Square ◽  
Statistical Property ◽  
Step Functions ◽  
Mean Square Response ◽  
The Mean ◽  
Thermoviscoelastic Medium

The mean-square wave response of a lightly damped thermoviscoelastic medium to a special type of nonstationary random excitation is determined. The excitation function on the thermoviscoelastic medium is taken in the form of a product of a well-defined, slowly varying envelope function, and a part which prescribes the statistical characteristics of the excitation. Both the unit step and rectangular step functions are used for the envelope function, and both white noise and noise with an exponentially decaying harmonic correlation function are used to prescribe the statistical property of the excitation. By taking into consideration the slow variation envelope function and the wave characteristics of the lightly damped thermoviscoelastic medium, the mean-square response (as a function of temperature, excitation, and damping parameters with the aid of reversible and irreversible thermodynamics) is evaluated.

Non-Linear Model of Rubber Bearings under Random Excitation

2012 ◽  
Vol 452-453 ◽  
pp. 602-606
Author(s):  
Hai Yan Jing ◽  
Yan Ping Zheng ◽  
Ming Xia Fang
Keyword(s):  
Past Research ◽  
Random Excitation ◽  
Mean Value ◽  
Statistical Characteristics ◽  
The Past ◽  
Non Linear ◽  
The Mean ◽  
Rubber Bearings ◽  
Force Displacement ◽  
Sinusoidal Excitation

Through dynamics test and theoretical analysis about rubber bearings in Auto body’s sub-frame, and the past research results of sinusoidal excitation, a hysteretic non-linear mathematical model of the rubber bearings is established under the condition of random excitation. The model shows that the hysteretic renewed force of the rubber bearings under random excitation can be expressed with the mean value and variance of random excitation’s statistical characteristics and speed. Finally curves of the hysteretic renewed force - displacement are reconstructed with the model built, which match the test’s results well.

scholarly journals Statistical Properties of SNR for Compressed Measurements

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Yulong Gao ◽  
Yanping Chen ◽  
Linxiao Su
Keyword(s):  
Numerical Simulation ◽  
Signal Processing ◽  
Distribution Function ◽  
Cumulative Distribution Function ◽  
Statistical Properties ◽  
Cumulative Distribution ◽  
Statistical Characteristics ◽  
Communication Signal ◽  
The Mean ◽  
Simulation Results

Some basic statistical properties of the compressed measurements are investigated. It is well known that the statistical properties are a foundation for analyzing the performance of signal detection and the applications of compressed sensing in communication signal processing. Firstly, we discuss the statistical properties of the compressed signal, the compressed noise, and their corresponding energy. And then, the statistical characteristics of SNR of the compressed measurements are calculated, including the mean and the variance. Finally, probability density function and cumulative distribution function of SNR are derived for the cases of the Gamma distribution and the Gaussian distribution. Numerical simulation results demonstrate the correctness of the theoretical analysis.

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