scholarly journals Forecasting the life of a structure relative to the operating mode

2021 ◽  
Vol 2094 (4) ◽  
pp. 042061
Author(s):  
D A Ogorelkov ◽  
O A Lukashuk
Keyword(s):  
Normal Distribution ◽  
Service Time ◽  
Operating Mode ◽  
Operating Conditions ◽  
Design Calculation ◽  
Metallic Structure ◽  
Load Spectrum ◽  
The Real ◽  
The Law ◽  
High Level

Abstract The question of forecasting the service life of transport machines designed by taking into consideration the load spectrum, that is close to the real one, is an important problem at the calculation. One of the ways to simulate real operating conditions at the design calculation is a method of randomization quasirandom loads. Methods of randomization are widely used in many areas of science and technique. In the article, the numeric comparison of different ways of randomization is shown at the calculation for determining the service time using two techniques: the use of a standardized function of randomization in the high-level programming language of the and the law of normal distribution at its different parameters. The use of the law of normal distribution makes the more exact fatigue calculation because it makes it possible to simulate the quasirandom process that corresponds to the real operation picture to a greater degree. The results presented in the work make it possible to fulfill the calculation of the service time of the metallic structure that is under cyclic asymmetric loads, at the well-known nature of the application of loading to it.

scholarly journals Analysis of the Influence of Demographic Indicators on Satisfaction with Stationary Physical Therapy among Cardiosurgical Patients

2020 ◽  
Vol 5 (5) ◽  
pp. 258-264
Author(s):  
V. V. Vitomskyi ◽  
◽  
Keyword(s):  
Cardiac Surgery ◽  
Physical Therapy ◽  
Normal Distribution ◽  
Physical Therapists ◽  
Physical Therapist ◽  
Correct Diagnosis ◽  
Mean Value ◽  
Level Of Satisfaction ◽  
The Law ◽  
High Level

The purpose of the study was to assess satisfaction with physical therapy received during a stay in a cardiac surgery hospital, and to investigate the influence of gender and age of patients on its level. Material and methods. The study involved 87 patients (men n = 56; women n = 31; age 61.59±11.41 years) who underwent cardiac surgery. An adapted version of the Physical Therapy Satisfaction Questionnaire was used to assess satisfaction, which consisted of 17 statements. The obtained results were processed by methods of mathematical statistics. As the results of the vast majority of indicators did not comply with the law of normal distribution, the median (Me) and upper and lower quartiles (25%; 75%) were calculated. For the results of indicators that corresponded to the law of normal distribution, the mean value and the standard deviation (±S) were additionally calculated. To assess the significance of the difference, in the presence of a normal distribution of research results, Student's t-test (for independent groups) was used, and for indicators with a different distribution than normal, Mann-Whitney U-test (for independent groups) and χ2 test were used. Spearman's correlation rank criterion was used to study the effect of age on satisfaction with physical therapy. Results and discussion. Comparison of the results of men and women did not reveal significant differences in the results of the survey. Only two items (explaining the reasons for physical therapy; waiting after the appointment) out of seventeen had a significant inverse relationship with age, but its strength was weak. The results of all points of satisfaction with physical therapy were high. Most patients agreed or completely agreed with the statement of the questionnaire. The answer "uncertain" was observed much less often. In the analysis of the obtained indicators of satisfaction in the general sample of patients, the best results were obtained in the seventh item of the questionnaire (friendliness and politeness), the thirteenth (respect for the physical therapist) and the first (explanation of the reasons for physical therapy). The lowest scores were obtained in the third (the feeling the correct diagnosis of physical therapists), fifth (access to the necessary physical therapists for feedback on physical therapy procedures), sixteenth (matching the patient's ability to physical therapy). The reasons which could influence decrease in estimates in indicators with the lowest results are considered. The total score of all items was 81 (77; 85) points. Taking into account that the theoretical maximum is 85 points and a minimum of 17 points (with the answers "strongly disagree" in all points), the median was 94% of the maximum result, which further confirms the high level of patient satisfaction. Conclusion. The age and sex of cardiac surgery patients did not affect the level of satisfaction with physical therapy. The survey of patients confirmed a high level of satisfaction

Durability Study of a Machine Shaft Based on the Material Behavior of 41Cr4 Steel Subjected to Rotating Bending

2012 ◽  
Vol 188 ◽  
pp. 256-261
Author(s):  
Lorand Kun ◽  
Cristian Sorin Nes ◽  
Ion Dumitru ◽  
Nicolae Faur
Keyword(s):  
Equivalent Stress ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Material Behavior ◽  
Load Spectrum ◽  
Premature Failure ◽  
The Real ◽  
Durability Analysis ◽  
Rotating Bending

This paper presents the durability analysis of a machine shaft subjected to bending with torsion, based upon the stress analysis at a notch which joins segments of different cross-sections (circular and square respectively) of the shaft. During the specific operating conditions of the equipment which’s part the shaft is, this notch has proven to be critical, causing premature failure. The durability analysis is carried out based on the real loading conditions, allowing the stress state evaluation at the base of the notch for different radii, using ABAQUS 6.9-3 finite element analysis program. The experimental studies carried out on the shaft’s material, 41Cr4 steel, resulted in the determination of material properties and of torsion fatigue curves in case of two different heat treatments. The cycles composing the equivalent stress spectrum are counted using the rainflow algorithm. The number of loading blocks to failure (number of load spectrum repetitions), considering the real operating conditions, is obtained using Miner’s rule, based on the rotating bending fatigue curve, corrected corresponding to the shaft’s specific characteristics. The proposed calculation method, based on the variation in time of the stress tensor during operating conditions, leads to the determination of the optimal notch radius for which the shaft’s durability falls between prescribed limits.

scholarly journals Method for determining the actual group of classification (mode of operation) of load-lifting cranes

2021 ◽  
Author(s):  
Oleksiy Nyezhentsev
Keyword(s):  
Specific Energy Consumption ◽  
Operating Mode ◽  
Technical Condition ◽  
Operating Conditions ◽  
Safe Operation ◽  
The Real ◽  
Mode Of Operation ◽  
Definition Of ◽  
Actual Classification

The problems which arise during the period of expert inspection of the load-lifting cranes which have fulfilled regulatory lifetime, at definition of their actual group of classification (operating mode) are analyzed. It is established that the actual group of classification (mode of operation) of operated cranes, which is determined by the regulations on labor protection (NPAOP), often does not coincide with the passport modes of operation of cranes. A new method of diagnosing the actual classification group (operating mode) of operated cranes has been developed, which allows taking into account the real modes of their loading and classes of use using the value of specific energy consumption of cranes. The proposed method allows to reliably determining the actual group of classification of cranes that have served the regulatory lifetime, taking into account the real operating conditions of all crane mechanisms and their technical condition for the entire period of operation. This makes it possible to reasonably and qualitatively establish the terms and conditions of further safe operation of cranes.

“Farewell to Unjustified Enrichment?” – A Common Law Response

2016 ◽  
Vol 20 (3) ◽  
pp. 326-337
Author(s):  
Steve Hedley
Keyword(s):  
Common Law ◽  
German Law ◽  
Unjust Enrichment ◽  
Level Of Abstraction ◽  
The Law ◽  
Unjustified Enrichment ◽  
High Level ◽  
Logical Process

In this article, Professor Steve Hedley offers a Common Law response to he recently published arguments of Professor Nils Jansen on the German law of unjustified enrichment (as to which, see Jansen, “Farewell to Unjustified Enrichment” (2016) 20 EdinLR 123). The author takes the view that Jansen's paper provided a welcome opportunity to reconsider not merely what unjust enrichment can logically be, but what it is for. He argues that unjust enrichment talk contributes little of value, and that the supposedly logical process of stating it at a high level of abstraction, and then seeking to deduce the law from that abstraction, merely distracts lawyers from the equities of the cases they consider.

THE 2017 AMENDMENTS TO THE LAW REFORM (MARRIAGE AND DIVORCE) ACT 1976: A MILESTONE OR A STONE’S THROW IN THE DEVELOPMENT OF MALAYSIAN FAMILY LAW?

2020 ◽  
Vol 28 (2) ◽  
pp. 449-479
Author(s):  
Sridevi Thambapillay
Keyword(s):  
Child Custody ◽  
Family Law ◽  
Law Reform ◽  
The Real ◽  
The Past ◽  
Marriage And Divorce ◽  
Conversion To Islam ◽  
Family Issues ◽  
The Law ◽  
Muslim Family

The Law Reform (Marriage and Divorce) Act 1976 (LRA) which was passed in 1976 and came into force on 1st March 1982, standardized the laws concerning non-Muslim family matters. Many family issues concerning non-Muslim have emerged ever since, the most important being the effects of unilateral conversion to Islam by one of the parties to the marriage. There has been a lot of public hue and cry for amendments to be made to the LRA. After much deliberation, the Malaysian Parliament finally passed the amendments to the LRA in October 2017, which came into force in December 2018. Although the amendments have addressed selected family law issues, the most important amendment on child custody in a unilateral conversion to Islam was dropped from the Bill at the last minute. Howsoever, at the end of the day, the real question that needs to be addressed is whether the amendments have resolved the major issues that have arisen over the past four decades? Hence, the purpose of this article is as follows: first, to examine the brief background to the passing of the LRA, secondly, to analyse the 2017 amendments, thirdly, to identify the weaknesses that still exist in the LRA, and finally, to suggest recommendations to overcome these weaknesses by comparing the Malaysian position with the Singaporean position. In conclusion, it is submitted that despite the recent amendments to the LRA, much needs to be done to overcome all the remaining issues that have still not been addressed.

Power Test System Development and Dynamic Performance State Estimation Based on Hub Motor Vehicle

2020 ◽  
Vol 13 (2) ◽  
pp. 126-140
Author(s):  
Jing Gan ◽  
Xiaobin Fan ◽  
Zeng Song ◽  
Mingyue Zhang ◽  
Bin Zhao
Keyword(s):  
Real Time ◽  
Dynamic Performance ◽  
Test System ◽  
Operating Conditions ◽  
Motor Vehicles ◽  
Maximum Speed ◽  
Performance Parameters ◽  
Power Performance ◽  
Power Test ◽  
The Real

Background: The power performance of an electric vehicle is the basic parameter. Traditional test equipment, such as the expensive chassis dynamometer, not only increases the cost of testing but also makes it impossible to measure all the performance parameters of an electric vehicle. Objective: A set of convenient, efficient and sensitive power measurement system for electric vehicles is developed to obtain the real-time power changes of hub-motor vehicles under various operating conditions, and the dynamic performance parameters of hub-motor vehicles are obtained through the system. Methods: Firstly, a set of on-board power test system is developed by using virtual instrument (Lab- VIEW). This test system can obtain the power changes of hub-motor vehicles under various operating conditions in real-time and save data in real-time. Then, the driving resistance of hub-motor vehicles is analyzed, and the power performance of hub-motor vehicles is studied in depth. The power testing system is proposed to test the input power of both ends of the driving motor, and the chassis dynamometer is combined to test so that the output efficiency of the driving motor can be easily obtained without disassembly. Finally, this method is used to carry out the road test and obtain the vehicle dynamic performance parameters. Results: The real-time current, voltage and power, maximum power, acceleration time and maximum speed of the vehicle can be obtained accurately by using the power test system in the real road experiment. Conclusion: The maximum power required by the two motors reaches about 9KW, and it takes about 20 seconds to reach the maximum speed. The total power required to maintain the maximum speed is about 7.8kw, and the maximum speed is 62km/h. In this article, various patents have been discussed.

Features of accumulation of amounts of measurement error

2017 ◽  
Vol 928 (10) ◽  
pp. 58-63 ◽  
Author(s):  
V.I. Salnikov
Keyword(s):  
Measurement Error ◽  
Confidence Interval ◽  
Normal Distribution ◽  
Confidence Level ◽  
Measurement Errors ◽  
Truncated Normal Distribution ◽  
Truncated Normal ◽  
The Law ◽  
Normal Law

The initial subject for study are consistent sums of the measurement errors. It is assumed that the latter are subject to the normal law, but with the limitation on the value of the marginal error Δpred = 2m. It is known that each amount ni corresponding to a confidence interval, which provides the value of the sum, is equal to zero. The paradox is that the probability of such an event is zero; therefore, it is impossible to determine the value ni of where the sum becomes zero. The article proposes to consider the event consisting in the fact that some amount of error will change value within 2m limits with a confidence level of 0,954. Within the group all the sums have a limit error. These tolerances are proposed to use for the discrepancies in geodesy instead of 2m*SQL(ni). The concept of “the law of the truncated normal distribution with Δpred = 2m” is suggested to be introduced.

scholarly journals DeepFogSim: A Toolbox for Execution and Performance Evaluation of the Inference Phase of Conditional Deep Neural Networks with Early Exits Atop Distributed Fog Platforms

2021 ◽  
Vol 11 (1) ◽  
pp. 377
Author(s):  
Michele Scarpiniti ◽  
Enzo Baccarelli ◽  
Alireza Momenzadeh ◽  
Sima Sarv Ahrabi
Keyword(s):  
Neural Networks ◽  
Real Time ◽  
Future Internet ◽  
Operating Conditions ◽  
Graphic User Interface ◽  
Energy Aware ◽  
Internet Applications ◽  
The Real ◽  
Delay Performance ◽  
Hard Constraints

The recent introduction of the so-called Conditional Neural Networks (CDNNs) with multiple early exits, executed atop virtualized multi-tier Fog platforms, makes feasible the real-time and energy-efficient execution of analytics required by future Internet applications. However, until now, toolkits for the evaluation of energy-vs.-delay performance of the inference phase of CDNNs executed on such platforms, have not been available. Motivated by these considerations, in this contribution, we present DeepFogSim. It is a MATLAB-supported software toolbox aiming at testing the performance of virtualized technological platforms for the real-time distributed execution of the inference phase of CDNNs with early exits under IoT realms. The main peculiar features of the proposed DeepFogSim toolbox are that: (i) it allows the joint dynamic energy-aware optimization of the Fog-hosted computing-networking resources under hard constraints on the tolerated inference delays; (ii) it allows the repeatable and customizable simulation of the resulting energy-delay performance of the overall Fog execution platform; (iii) it allows the dynamic tracking of the performed resource allocation under time-varying operating conditions and/or failure events; and (iv) it is equipped with a user-friendly Graphic User Interface (GUI) that supports a number of graphic formats for data rendering. Some numerical results give evidence for about the actual capabilities of the proposed DeepFogSim toolbox.

Proving the Labeled Interval Calculus for Inferences on Catalogs

1990 ◽  
Author(s):  
Walid Habib ◽  
Allen C. Ward
Keyword(s):  
Mechanical Design ◽  
Formal System ◽  
Constraint Propagation ◽  
Operating Conditions ◽  
Manufacturing Processes ◽  
Entire System ◽  
High Level Language ◽  
Design Problems ◽  
High Level ◽  
Interval Constraint

Abstract The “labeled interval calculus” is a formal system that performs quantitative inferences about sets of artifacts under sets of operating conditions. It refines and extends the idea of interval constraint propagation, and has been used as the basis of a program called a “mechanical design compiler,” which provides the user with a “high level language” in which design problems for systems to be built of cataloged components can be quickly and easily formulated. The compiler then selects optimal combinations of catalog numbers. Previous work has tested the calculus empirically, but only parts of the calculus have been proven mathematically. This paper presents a new version of the calculus and shows how to extend the earlier proofs to prove the entire system. It formalizes the effects of toleranced manufacturing processes through the concept of a “selectable subset” of the artifacts under consideration. It demonstrates the utility of distinguishing between statements which are true for all artifacts under consideration, and statements which are merely true for some artifact in each selectable subset.

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