scholarly journals BUILDING MODELS OF FREIGHT CARS REFUSALS INVOLVING BAYESIAN APPROACH

2016 ◽  
Vol 1 ◽  
pp. 54-60
Author(s):  
Leontii Muradian
Keyword(s):  
Mechanical Properties ◽  
Bayesian Approach ◽  
Posterior Probability ◽  
Likelihood Function ◽  
A Priori ◽  
Physical And Mechanical Properties ◽  
Total Probability ◽  
Knowledge Process ◽  
Building Models ◽  
Additional Value

Based on the theoretical analysis and Bayesian statistics ordinary shown that Bayesian analysis begins with the known data from the following consideration changes in knowledge process of obtaining new information and mathematical statistics methods of sample observation comes only with the knowledge of some group of objects. Using Bayesian formula, we can determine the probability of any event, provided that there was another statistically correlated with it an event that counted with greater accuracy the likelihood. This used previously known information and data obtained as a result of new observations. The study of failures of freight cars, the Bayesian approach allows you to evaluate the occurrence of each failure of parts or assemblies separately, as well as through changes in the formula for the total probability. The paper, based on Bayesian method was done combining two models: the failures of freight cars and the changing physical and mechanical properties of composite materials. This posterior probability determined a priori probability of failures given using the model change of physical and mechanical properties and the likelihood function that takes into account the additional value failures. Using the expression for the posterior probability held specification mentioned developments (run) freight wagon to failure.

scholarly journals Mathematical simulation of welded deposit layers as for adaptation of materials to failure in quasidissipative tribosystems

2021 ◽  
pp. 82-87
Author(s):  
S. Popov ◽  
S. Shumykin ◽  
Н. Laptieva
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Mathematical Models ◽  
A Priori ◽  
Structural Phase ◽  
Scientific Research ◽  
Physical And Mechanical Properties ◽  
Regression Equations ◽  
Mathematical Planning ◽  
Active Experiment

Purpose. To establish mathematical models for the adaptation of materials under conditions of activation of a metastable structural-phase state of quasi-dissipative tribosystems. Determination and substantiation of factors for planning an active experiment due to which it is possible to create mathematical models of stable forecasts for increasing the wear resistance of materials. Research methods. When conducting the experiments, a priori data were used in combination with our own scientific developments of mathematical models of the dependences of the influence of the chemical composition of alloys during manual and automatic electric arc surfacing on the physical and mechanical properties of the surface layer of the material, which is destroyed under tribosystem conditions. It was decided to use mathematical planning of research on the basis of an active experiment with the creation of models for the numerical description of the mathematical expectation in the form of regression equations. Obtained results. On the basis of theoretical and practical scientific research with planning a passive and active experiment, a set of relevant knowledge has been obtained, which makes it possible to determine the main criterion requirements for the sensitivity of deposited steels and alloys to adaptation under the action of external mechanical and energy influences and allows to mathematically describe the characteristics of the alloy and provide a numeri­cal estimate of the correlation parameters among themselves. On the basis of the theory of scientific mathematical planning of the experiment, a set of corresponding experiments was carried out, which made it possible to build spatial graphic models. Scientific novelty. For the first time, theoretical and practical scientific research is presented with the reproduction of a systemic multivariate analysis of the parameters of mathematical models and processes leading to the martensitic ( γ → α ) transformation and determines the substantiation of the chemical composition of the deposited materials to increase fracture resistance under conditions of quasi-dissipative and dissipative tribosystems. Practical meaning. The obtained results of the above studies allow, within the framework of technical and technological accuracy, which is necessary within the framework of practical engineering forecasts, to determine the physical and mechanical properties of wear-resistant deposited alloys under conditions of quasi-dissipative and dissipative tribosystems.

USING FULL PROBABILITY MODELS TO COMPUTE PROBABILITIES OF ACTUAL INTEREST TO DECISION MAKERS

2001 ◽  
Vol 17 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Frank E. Harrell ◽  
Ya-Chen Tina Shih
Keyword(s):  
Bayesian Approach ◽  
Posterior Distribution ◽  
Prior Distribution ◽  
Likelihood Function ◽  
Scientific Evidence ◽  
A Priori ◽  
Relevant Information ◽  
Decision Makers ◽  
Probability Models ◽  
The Bayesian Approach

The objective of this paper is to illustrate the advantages of the Bayesian approach in quantifying, presenting, and reporting scientific evidence and in assisting decision making. Three basic components in the Bayesian framework are the prior distribution, likelihood function, and posterior distribution. The prior distribution describes analysts' belief a priori; the likelihood function captures how data modify the prior knowledge; and the posterior distribution synthesizes both prior and likelihood information. The Bayesian approach treats the parameters of interest as random variables, uses the entire posterior distribution to quantify the evidence, and reports evidence in a “probabilistic” manner. Two clinical examples are used to demonstrate the value of the Bayesian approach to decision makers. Using either an uninformative or a skeptical prior distribution, these examples show that the Bayesian methods allow calculations of probabilities that are usually of more interest to decision makers, e.g., the probability that treatment A is similar to treatment B, the probability that treatment A is at least 5% better than treatment B, and the probability that treatment A is not within the “similarity region” of treatment B, etc. In addition, the Bayesian approach can deal with multiple endpoints more easily than the classic approach. For example, if decision makers wish to examine mortality and cost jointly, the Bayesian method can report the probability that a treatment achieves at least 2% mortality reduction and less than $20,000 increase in costs. In conclusion, probabilities computed from the Bayesian approach provide more relevant information to decision makers and are easier to interpret.

PEMANFAATAN KAYU AKASIA MANGIUM (Acacia mangium Willd) UNTUK MEBEL

2012 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Djoko Purwanto
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical Properties ◽  
Treatment Process ◽  
Acacia Mangium ◽  
Physical And Mechanical Properties ◽  
Wood Fibers ◽  
Test Parameters ◽  
Mechanical And Physical Properties ◽  
Scale Scores

Timber Acacia mangium (Acacia mangium, Willd) for Furniture. The study aims to determine the mechanical and physical properties and the decorative value (color and fiber) wood of acacia mangium with using finishing materials. This type of finishing material used is ultran lasur natural dof ,ultran lasur classic teak, aqua politur clear dof, aqua politur akasia dan aqua politur cherry. After finishing the wood is stored for 3 months. Test parameters were observed, namely, physical and mechanical properties of wood, adhesion of finishing materials, color and appearance of the fiber, and timber dimensions expansion. The results showed that the mechanical physical properties of acacia wood qualified SNI. 01-0608-89 about the physical and mechanical properties of wood for furniture, air dry the moisture content from 13.78 to 14.89%, flexural strength from 509.25 to 680.50 kg/cm2, and compressive strength parallel to fiber 342.1 - 412.9 kg/cm2. Finishing the treatment process using five types of finishing materials can increase the decorative value (color and fiber) wood. Before finishing the process of acacia mangium wood has the appearance of colors and fibers and less attractive (scale scores 2-3), after finishing acacia wood fibers have the appearance of colors and interesting and very interesting (scale 4-5).Keywords: mangium wood, mechanical properties, decorative value, finishing, furniture.

Physical and Mechanical Properties of Tenun Pahang Fabrics using Alternative Yarns

2016 ◽  
Vol 13 (2) ◽  
pp. 67
Author(s):  
Engku Liyana Zafirah Engku Mohd Suhaimi ◽  
Jamil Salleh ◽  
Suzaini Abd Ghani ◽  
Mohamad Faizul Yahya ◽  
Mohd Rozi Ahmad
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
The Other ◽  
Silk Fabrics ◽  
Recovery Angle ◽  
Made In

An investigation on the properties of Tenun Pahang fabric performances using alternative yarns was conducted. The studies were made in order to evaluate whether the Tenun Pahang fabric could be produced economically and at the same time maintain the fabric quality. Traditional Tenun Pahang fabric uses silk for both warp and weft. For this project, two alternative yarns were used which were bamboo and modal, which were a little lower in cost compared to silk. These yarns were woven with two variations, one with the yarns as weft only while maintaining the silk warp and the other with both warp and weft using the alternative yarns. Four (4) physical testings and three (3) mechanical testings conducted on the fabric samples. The fabric samples were evaluated including weight, thickness, thread density, crease recovery angle, stiffness and drapability. The results show that modal/silk and bamboo silk fabrics are comparable in terms of stiffness and drapability, hence they have the potential to replace 100% silk Tenun Pahang.

Basic set of experiments for determination of mechanical properties of sand

2014 ◽  
Vol 62 (1) ◽  
pp. 129-137
Author(s):  
A. Sawicki ◽  
J. Mierczyński
Keyword(s):  
Mechanical Properties ◽  
Soil Mechanics ◽  
Physical And Mechanical Properties ◽  
Local Strain ◽  
Initial State ◽  
Laboratory Equipment ◽  
Additional Information ◽  
Basic Set ◽  
Initial Anisotropy

Abstract A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.

PREPARATION AND CHARACTERIZATION OF REPROCESSED COMPOSITES OF POLYPROPYLENE REINFORCED BY WOOD FIBERS: PHYSICAL AND MECHANICAL PROPERTIES

2017 ◽  
Author(s):  
Thais Helena Sydenstricker Flores-Sahagun ◽  
Kelly Priscila Agapito ◽  
ROSA MARIA JIMENEZ AMEZCUA ◽  
Felipe Jedyn
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Wood Fibers
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