A Statistical Load Weighted Average Fatigue Reliability Model for Uncertain Constant Amplitude Cyclic Load

2007 ◽  
Vol 353-358 ◽  
pp. 2497-2500
Author(s):  
Li Yang Xie ◽  
Xue Hong He
Keyword(s):  
Cyclic Load ◽  
Weighted Average ◽  
Random Variable ◽  
Amplitude Distribution ◽  
General Situation ◽  
Fatigue Reliability ◽  
Constant Amplitude ◽  
Statistical Average ◽  
Assigned Value ◽  
The Individual

The present paper interpreted the traditional stress-strength interference model as an equation expressing the statistical average of the probability of strength preponderating over stress. Thus, the same equation, which was traditionally applicable only in the situation of same-measure parameters, can be applied to more general situation of different-measure parameters. In other words, the traditional model was extended to the situation of any two variables, as long as one variable can be expressed as a function of the other. With a specific load amplitude distribution, the method is to calculate the statistical average of the probability that fatigue life random variable under the individual constant amplitude cyclic load is greater than an assigned value. The extended interference analysis method can be applied directly to calculate fatigue reliability under constant amplitude cyclic load with uncertainty in the stress range.

A Statistically Load-Weighted Probabilistic Fatigue Life Model

2008 ◽  
Vol 44-46 ◽  
pp. 51-56 ◽  
Author(s):  
Li Yang Xie ◽  
Wen Qiang Lin
Keyword(s):  
Fatigue Life ◽  
Stress Amplitude ◽  
Random Variable ◽  
Cyclic Stress ◽  
General Situation ◽  
Statistical Average ◽  
Underlying Principle ◽  
Model Configuration ◽  
System Of Units ◽  
Life Model

By interpreting traditional stress-strength interference model as a statistical average of the probability that strength (a random variable) is greater than stress (another random variable) over its whole distribution range, the same model configuration, which was conventionally applied only to the case of same system-of-units parameters (e.g., stress and strength, both are measured in MPa), was applied to more general situation of different system-of-units parameters. That is to say, the traditional model was extended to more general situations of any two variables, as long as one of the variables can be expressed as a function of the other. Further more, the probabilistic fatigue life under random stress can be predicted, with known probabilistic fatigue lives under several deterministic cyclic stress amplitudes and known distribution of the random cyclic stress amplitude. The underlying principle is that the fatigue life under random stress is equal to the statistical average of the fatigue lives under cyclic stress of deterministic amplitudes which can be considered as the samples of the random stress.

scholarly journals A Novel Multi-Criteria Group Decision-Making Approach Based on Bonferroni and Heronian Mean Operators under Hesitant 2-Tuple Linguistic Environment

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1489
Author(s):  
Shahzad Faizi ◽  
Wojciech Sałabun ◽  
Nisbha Shaheen ◽  
Atiq ur Rehman ◽  
Jarosław Wątróbski
Keyword(s):  
Decision Making ◽  
Group Decision Making ◽  
Group Decision ◽  
Weighted Average ◽  
Aggregation Operators ◽  
Bonferroni Mean ◽  
Operational Laws ◽  
Geometric Bonferroni Mean ◽  
The Individual ◽  
Heronian Mean

Ambiguous and uncertain facts can be handled using a hesitant 2-tuple linguistic set (H2TLS), an important expansion of the 2-tuple linguistic set. The vagueness and uncertainty of data can be grabbed by using aggregation operators. Therefore, aggregation operators play an important role in computational processes to merge the information provided by decision makers (DMs). Furthermore, the aggregation operator is a potential mechanism for merging multisource data which is synonymous with cooperative preference. The aggregation operators need to be studied and analyzed from various perspectives to represent complex choice situations more readily and capture the diverse experiences of DMs. In this manuscript, we propose some valuable operational laws for H2TLS. These new operational laws work through the individual aggregation of linguistic words and the collection of translation parameters. We introduced a hesitant 2-tuple linguistic weighted average (H2TLWA) operator to solve multi-criteria group decision-making (MCGDM) problems. We also define hesitant 2-tuple linguistic Bonferroni mean (H2TLBM) operator, hesitant 2-tuple linguistic geometric Bonferroni mean (H2TLGBM) operator, hesitant 2-tuple linguistic Heronian mean (H2TLHM) operator, and a hesitant 2-tuple linguistic geometric Heronian mean (H2TLGHM) operator based on the novel operational laws proposed in this paper. We define the aggregation operators for addition, subtraction, multiplication, division, scalar multiplication, power and complement with their respective properties. An application example and comparison analysis were examined to show the usefulness and practicality of the work.

Bachelorhood and Sexuality in a Context of Female Shortage: Evidence from a Survey in Rural Anhui, China

2013 ◽  
Vol 215 ◽  
pp. 703-726 ◽  
Author(s):  
Isabelle Attané ◽  
Zhang Qunlin ◽  
Li Shuzhuo ◽  
Yang Xueyan ◽  
Christophe Z. Guilmoto
Keyword(s):  
Cultural Context ◽  
Family Formation ◽  
Rural Society ◽  
General Situation ◽  
Rural County ◽  
Chinese Men ◽  
Married Men ◽  
Exploratory Survey ◽  
The Individual ◽  
Near Future

AbstractTraditionally, marriage is a near universality in China. However, in the coming decades, owing to the growing sex imbalance, millions of men will be unable to marry. As a consequence, bachelorhood is becoming a new demographic concern, particularly affecting men from the most disadvantaged socio-economic groups. In China's cultural context today, heterosexual marriage remains a prerequisite for family formation and, in rural society particularly, the legitimate setting for sexual activity. Under such circumstances, bachelorhood is likely to produce privations on various fronts, the consequences of which for both the individual and the community are still largely unknown. This article focuses on the opinions and sexual behaviour of bachelors, and highlights significant variations from those of married men. It is based on the findings of an exploratory survey conducted in 2008 in selected villages in a rural county in Anhui province, referred to here as JC county. The survey provides insights into the more general situation of rural men unable to marry in a context of female shortage, and indicates the conditions a growing number of Chinese men will face in the near future.

scholarly journals Flexibility Reserve of Self-Consumption Optimized Energy Systems in the Household Sector

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3017
Author(s):  
Elias Dörre ◽  
Sebastian Pfaffel ◽  
Alexander Dreher ◽  
Pedro Girón ◽  
Svenja Heising ◽  
...  
Keyword(s):  
Unit Commitment ◽  
Programming Model ◽  
Weighted Average ◽  
Heat Pumps ◽  
Mixed Integer ◽  
Single Family ◽  
Unit Commitment Problem ◽  
Household Sector ◽  
The Future ◽  
The Individual

Energy generation and consumption in the power grid must be balanced at every single moment. Within the synchronous area of continental Europe, flexible generators and loads can provide Frequency Containment Reserve and Frequency Restoration Reserve marketed through the balancing markets. The Transmission System Operators use these flexibilities to maintain or restore the grid frequency when there are deviations. This paper shows the future flexibility potential of Germany’s household sector, in particular for single-family and twin homes in 2025 and 2030 with the assumption that households primarily optimize their self-consumption. The primary focus is directed to the flexibility potential of Electric Vehicles, Heat Pumps, Photovoltaics and Battery Storage Systems. A total of 10 different household system configurations were considered and combined in a weighted average based on the scenario framework of the German Grid Development Plan. The household generation, consumption and storage units were simulated in a mixed-integer linear programming model to create the time series for the self-consumption optimized households. This solved the unit commitment problem for each of the decentralized households in their individual configurations. Finally, the individual household flexibilities were evaluated and then aggregated to a Germany-wide flexibility profile for single-family and twin homes. The results indicate that the household sector can contribute significantly to system stabilization with an average potential of 30 negative and 3 positive flexibility in 2025. In 2030, the corresponding flexibilities potentially increase to 90 and 30 , respectively. This underlines that considerable flexibility reserves could be provided by single-family and twin homes in the future.

scholarly journals THE COMPARISON OF TREE QUALITIES

1965 ◽  
Vol 41 (2) ◽  
pp. 215-221
Author(s):  
P. L. Northcott
Keyword(s):  
Computer Program ◽  
Linear Combination ◽  
Digital Computer ◽  
Weighted Average ◽  
Statistical Procedure ◽  
Weighted Sum ◽  
Average Quality ◽  
The Individual

The need to compare individuals is discussed briefly. It is suggested that the composite quality of an individual is best defined as the weighted sum of a number of measurable characteristics of the individual. A statistical procedure for comparison of weighted average quality is derived from application of the principle of the linear combination of variables. A digital computer program is available.

scholarly journals A consensus-based global optimization method for high dimensional machine learning problems

2020 ◽  
Author(s):  
Jose Carrillo ◽  
Shi Jin ◽  
Lei Li ◽  
Yuhua Zhu
Keyword(s):  
Optimization Problems ◽  
Computational Cost ◽  
Weighted Average ◽  
Planck Equation ◽  
Optimization Method ◽  
Learning Problems ◽  
High Dimensional ◽  
Nonconvex Functions ◽  
The Individual ◽  
Parameter Constraints

We improve recently introduced consensus-based optimization method, proposed in [R. Pinnau, C. Totzeck, O. Tse and S. Martin, Math. Models Methods Appl. Sci., 27(01):183{204, 2017], which is a gradient-free optimization method for general nonconvex functions. We rst replace the isotropic geometric Brownian motion by the component-wise one, thus removing the dimensionality dependence of the drift rate, making the method more competitive for high dimensional optimization problems. Secondly, we utilize the random mini-batch ideas to reduce the computational cost of calculating the weighted average which the individual particles tend to relax toward. For its mean- eld limit{a nonlinear Fokker-Planck equation{we prove, in both time continuous and semi-discrete settings, that the convergence of the method, which is exponential in time, is guaranteed with parameter constraints independent of the dimensionality. We also conduct numerical tests to high dimensional problems to check the success rate of the method.

Changes in Quantal Size Distributions Upon Experimental Variations in the Probability of Release at Striatal Inhibitory Synapses

1998 ◽  
Vol 79 (6) ◽  
pp. 2999-3011 ◽  
Author(s):  
Jan C. Behrends ◽  
Gerrit ten Bruggencate
Keyword(s):  
Amplitude Distribution ◽  
Inhibitory Synapses ◽  
Rat Striatum ◽  
Size Distributions ◽  
Presynaptic Neuron ◽  
Quantal Size ◽  
Vesicular Release ◽  
The Mean ◽  
The Individual ◽  
Whole Cell Recordings

Behrends, Jan C. and Gerrit ten Bruggencate. Changes in quantal size distributions upon experimental variations in the probability of release at striatal inhibitory synapses. J. Neurophysiol. 79: 2999–3011, 1998. Postsynaptic inhibitory γ-aminobutyric acid-A (GABAA)-receptor–mediated current responses were measured using simultaneous pre- and postsynaptic whole cell recordings in primary cell cultures of rat striatum. Substitution of Sr2+ for extracellular Ca2+ strongly desynchronized the inhibitory postsynaptic currents (IPSCs), resulting in a succession of asynchronous IPSCs (asIPSCs). The rise times and decay time constants of individual evoked asIPSCs were not significantly different from those of miniature IPSCs that are the result of spontaneous vesicular release of GABA. Thus asIPSCs reflect quantal transmission at the individual contacts made by one presynaptic neuron on the recorded postsynaptic cell. Increasing the concentration of Sr2+ from 2 to 10 mM and decreasing that of Mg2+ from 5 to 1 mM produced an increase in the frequency of asIPSCs consistent with an enhancement of the mean probability of release ( P r ). At the same time the amplitude distribution of asIPSCs was shifted toward larger values, whereas responses to exogenously applied GABA on average were slightly decreased in amplitude. Application of the GABAB-receptor agonist baclofen (3–10 μM) strongly reduced the frequency of asIPSC, consistent with a decrease in P r , and led to a shift of the amplitude distribution toward smaller values. Baclofen had no effect on responses to exogenously applied GABA. In summary, our data suggest that at striatal inhibitory connections the weight of single contacts may be controlled presynaptically by variation in the amount of transmitter released.

scholarly journals Statistical characteristics of sources of vehicle kinematic excitation

2020 ◽  
Vol 313 ◽  
pp. 00011
Author(s):  
Jozef Melcer ◽  
Eva Merčiaková ◽  
Mária Kúdelčíková
Keyword(s):  
Probability Theory ◽  
Spectral Density ◽  
Surface Quality ◽  
Correlation Functions ◽  
Random Variable ◽  
Point Of View ◽  
Statistical Characteristics ◽  
Kinematic Excitation ◽  
Power Spectral ◽  
The Individual

The longitudinal and transverse road profiles represent the functions of a random variable from a mathematical point of view. It is appropriate to use methods of probability theory and mathematical statistics for their description. The unevenness of the runway surface is the main source of the vehicle's kinematic excitation. This paper describes the statistical properties of the mapped road profiles. It shows a way of categorizing road surface quality based on the power spectral density of unevenness. The interrelationships between the individual points of the profile and the profiles with one another are evaluated by correlation functions.

scholarly journals Smoothing Algorithm for Planar and Surface Mesh Based on Element Geometric Deformation

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Shuli Sun ◽  
Minglei Zhang ◽  
Zhihong Gou
Keyword(s):  
Weighted Average ◽  
Processing Unit ◽  
Smoothing Algorithm ◽  
Surface Mesh ◽  
Polygonal Mesh ◽  
Second Stage ◽  
Geometric Deformation ◽  
Error Metric ◽  
The Individual

Smoothing is one of the basic procedures for improvement of mesh quality. In this paper, a novel and efficient smoothing approach for planar and surface mesh based on element geometric deformation is developed. The presented approach involves two main stages. The first stage is geometric deformation of all the individual elements through a specially designed two-step stretching-shrinking operation (SSO), which is performed by moving the vertices of each element according to a certain rule in order to get better shape of the element. The second stage is to determine the position of each node of the mesh by a weighted average strategy according to quality changes of its adjacent elements. The suggested SSO-based smoothing algorithm works efficiently for triangular mesh and can be naturally expanded to quadrilateral mesh, arbitrary polygonal mesh, and mixed mesh. Combined with quadratic error metric (QEM), this approach may be also applied to improve the quality of surface mesh. The proposed method is simple to program and inherently very suitable for parallelization, especially on graphic processing unit (GPU). Results of numerical experiments demonstrate the effectiveness and potential of this method.

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