scholarly journals THE QUANTIFICATION METHOD OF FUNCTIONAL AVAILABILITY MILITARY VEHICLES

2020 ◽  
Author(s):  
Kamil Przybysz
Keyword(s):  
Mathematical Model ◽  
Markov Process ◽  
Accurate Estimation ◽  
Technical Object ◽  
Quantification Method ◽  
Model Based ◽  
Military Vehicles ◽  
Operational Quality ◽  
Operational Data ◽  
Exploitation System

The availability is one of the most important feature of a technical object which shapes its operational quality. The paper undertakes the issue related to the quantification of functional availability of vehicles, with reference to reliability aspects. The conducted exploitation research paved the way for elaborating methods of determining functional availability for vehicles, in particular focusing on reliability. The essential research was conducted using the developed mathematical model based on the probabilistic, stochastic Markov process, which allowed modelling the process of changes in the exploitation states of vehicles. In view of the above, it is essential to develop methods that enable the most accurate estimation of the functional availability of vehicles. Knowing the values of functional availability, we can estimate the probability of performing assigned tasks and precisely control the vehicle exploitation system, especially in terms of availability, which is important for vehicles. This work presents a method for determining the functional availability of vehicles, taking into account the limitations introduced by the vehicle exploitation system.  Particular attention was paid to the possibility of using probabilistic, stochastic semiMarkov models, whose rules and method of creation were generally described, with regard to the ability to acquire operational data in the vehicle exploitation system.

scholarly journals An Analysis and Testing of Functional Availability Military Vehicles, in the Aspect of Reliability

2019 ◽  
Vol 49 (1) ◽  
pp. 405-423
Author(s):  
Kamil Przybysz
Keyword(s):  
Mathematical Model ◽  
Markov Process ◽  
Model Based ◽  
Military Vehicles ◽  
Different Types ◽  
The Military ◽  
Exploitation Intensity ◽  
The Way

Abstract The paper pertains to matters related to the quantification of functional availability of military vehicles, with reference to exploitation intensity and reliability aspects. The conducted exploitation research paved the way for elaborating methods of determining functional availability for military vehicles, in particular focusing on exploitation intensity and reliability. The essential research was conducted using the developed mathematical model based on the probabilistic, stochastic Markov process, which allowed modelling the process of changes in the exploitation states of military vehicles. In the course of the research, which enabled the authors to estimate the functional availability value, four-layered probes of the military vehicles were used (different types and makes), from the second exploitation phase, with varied mileage from the beginning of the exploitation and average mileage per year.

scholarly journals Is this the beginning or the end of COVID-19 outbreak in India? A data driven mathematical model-based analysis

2020 ◽  
Author(s):  
Anupam Singh ◽  
Jhilik Dey ◽  
Shivam Bhardwaj
Keyword(s):  
Mathematical Model ◽  
Epidemiological Data ◽  
Data Driven ◽  
Accurate Estimation ◽  
Model Based ◽  
Pessimistic Scenario ◽  
Spread Of Infection ◽  
Model Based Analysis

AbstractIndia has experienced an early and harshest lockdown from 25th March 2020 in response to the outbreak. However, an accurate estimation of the progression of the spread of infection and the level of preparedness to combat this disease are urgently needed. Using a data-based mathematical model, our study has made predictions on the number of cases that are expected to rise in India till 14th June 2020. The epidemiological data of daily cases have been utilized from 25th March (i.e., the first day of lockdown) to 23rd April 2020. In the study, we have stimulated two possible scenarios (optimistic and pessimistic) for the prediction. As per the optimistic approach of modelling, COVID-19 may end in the first week of June 2020 with a total of 77,900 infected cases including 2,442 fatalities. However, the results under the pessimistic scenario are a bit scary as it shows that a total of 283,300 infected cases with 10,180 fatalities till 14th June. To win the battle, 10 weeks of complete lockdown is much needed at least in the infected states and the union territories of India. Alternatively, the isolation of clusters (hotspot regions) is required if India wants a resume of some essential activities.

DETERMINATION OF PERFORMANCE INDICATORS OF THE TRUCK KrAZ-6510TE

2020 ◽  
pp. 19-26
Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar
Keyword(s):  
Mathematical Model ◽  
Surface Friction ◽  
Building Structures ◽  
Maximum Torque ◽  
Military Equipment ◽  
Military Vehicles ◽  
Force Magnitude ◽  
Vehicle Mobility ◽  
The Mathematical Model

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.

Optimal control strategy for cancer remission using combinatorial therapy: A mathematical model-based approach

2021 ◽  
Vol 145 ◽  
pp. 110789
Author(s):  
Parthasakha Das ◽  
Samhita Das ◽  
Pritha Das ◽  
Fathalla A. Rihan ◽  
Muhammet Uzuntarla ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Optimal Control ◽  
Control Strategy ◽  
Optimal Control Strategy ◽  
Combinatorial Therapy ◽  
Model Based ◽  
Cancer Remission

scholarly journals Research on a novel data-driven aging estimation method for battery systems in real-world electric vehicles

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110277
Author(s):  
Yankai Hou ◽  
Zhaosheng Zhang ◽  
Peng Liu ◽  
Chunbao Song ◽  
Zhenpo Wang
Keyword(s):  
Electric Vehicles ◽  
Real World ◽  
Regression Models ◽  
Estimation Method ◽  
Recursive Least Squares ◽  
Data Driven ◽  
Accurate Estimation ◽  
Support Vector ◽  
Battery Degradation ◽  
Operational Data

Accurate estimation of the degree of battery aging is essential to ensure safe operation of electric vehicles. In this paper, using real-world vehicles and their operational data, a battery aging estimation method is proposed based on a dual-polarization equivalent circuit (DPEC) model and multiple data-driven models. The DPEC model and the forgetting factor recursive least-squares method are used to determine the battery system’s ohmic internal resistance, with outliers being filtered using boxplots. Furthermore, eight common data-driven models are used to describe the relationship between battery degradation and the factors influencing this degradation, and these models are analyzed and compared in terms of both estimation accuracy and computational requirements. The results show that the gradient descent tree regression, XGBoost regression, and light GBM regression models are more accurate than the other methods, with root mean square errors of less than 6.9 mΩ. The AdaBoost and random forest regression models are regarded as alternative groups because of their relative instability. The linear regression, support vector machine regression, and k-nearest neighbor regression models are not recommended because of poor accuracy or excessively high computational requirements. This work can serve as a reference for subsequent battery degradation studies based on real-time operational data.

A note on design-based versus model-based variance estimation in stereology

2002 ◽  
Vol 34 (03) ◽  
pp. 484-490 ◽  
Author(s):  
Asger Hobolth ◽  
Eva B. Vedel Jensen
Keyword(s):  
Mathematical Model ◽  
Original Problem ◽  
Variance Estimation ◽  
Point Of View ◽  
Systematic Sampling ◽  
Variance Estimator ◽  
Shape Model ◽  
Model Based ◽  
Versus Model ◽  
Special Case

Recently, systematic sampling on the circle and the sphere has been studied by Gual-Arnau and Cruz-Orive (2000) from a design-based point of view. In this note, it is shown that their mathematical model for the covariogram is, in a model-based statistical setting, a special case of the p-order shape model suggested by Hobolth, Pedersen and Jensen (2000) and Hobolth, Kent and Dryden (2002) for planar objects without landmarks. Benefits of this observation include an alternative variance estimator, applicable in the original problem of systematic sampling. In a wider perspective, the paper contributes to the discussion concerning design-based versus model-based stereology.

scholarly journals 27 years of the HIV epidemic amongst men having sex with men in the Netherlands: An in depth mathematical model-based analysis

Epidemics ◽  
2010 ◽  
Vol 2 (2) ◽  
pp. 66-79 ◽  
Author(s):  
Daniela Bezemer ◽  
Frank de Wolf ◽  
Maarten C. Boerlijst ◽  
Ard van Sighem ◽  
T. Deirdre Hollingsworth ◽  
...  
Keyword(s):  
Mathematical Model ◽  
The Netherlands ◽  
Model Based ◽  
Hiv Epidemic ◽  
Sex With Men ◽  
Model Based Analysis

Fitting Spherical Surface and Evaluating Sphericity Error Based on the Minimum Zone Principle

2014 ◽  
Vol 687-691 ◽  
pp. 1373-1376 ◽  
Author(s):  
Lei Zhang ◽  
Li Li Liu ◽  
Chuan Hui Huang ◽  
Xing Hua Lu ◽  
Gen Sun
Keyword(s):  
Mathematical Model ◽  
Spherical Surface ◽  
Least Square ◽  
Model Based ◽  
Minimum Zone

To address the fitting spherical surface and evaluating sphericity error, a mathematical model based on the minimum zone principle is presented. And the presented model is answered by GA. An example shows the performance of the proposed method by comparison with the methods based on the least square principle.

scholarly journals Model-Based Design Approach to Improve Performance Characteristics of Hydrostatic Bearing Using Multivariable Optimization

Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 388
Author(s):  
Waheed Ur Rehman ◽  
Xinhua Wang ◽  
Yiqi Cheng ◽  
Yingchun Chen ◽  
Hasan Shahzad ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Feedback Control ◽  
External Load ◽  
Sliding Mode ◽  
Feedforward Control ◽  
Spindle Speed ◽  
Performance Criteria ◽  
Model Based ◽  
Hydrostatic Bearings ◽  
Robust Control Design

Research in the field of tribo-mechatronics has been gaining popularity in recent decades. The objective of the current research is to improve static/dynamics characteristics of hydrostatic bearings. Hydrostatic bearings always work in harsh environmental conditions that effect their performance, and which may even result in their failure. The current research proposes a mathematical model-based system for hydrostatic bearings that helps to improve its static/dynamic characteristics under varying conditions of performance-influencing variables such as temperature, spindle speed, external load, and clearance gap. To achieve these objectives, the capillary restrictors are replaced with servo valves, and a mathematical model is developed along with robust control design systems. The control system consists of feedforward and feedback control techniques that have not been applied before for hydrostatic bearings in the published literature. The feedforward control tries to remove a disturbance before it enters the system while feedback control achieves the objective of disturbance rejection and improves steady-state characteristics. The feedforward control is a trajectory-based controller and the feedback controller is a sliding mode controller with a PID sliding surface. The particle swarm optimization algorithm is used to tune the 6-dimensional vector of the tuning parameters with multi-objective performance criteria. Numerical investigations have been carried out to check the performance of the proposed system under varying conditions of viscosity, clearance gap, external load and the spindle speed. The comparison of our results with the published literature shows the effectiveness of the proposed system.

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