The Method of Complex Worthiness Assessment of an Engineering Object in the Process of its Use and Service

2008 ◽  
Vol 144 ◽  
pp. 45-52 ◽  
Author(s):  
Paweł Lindstedt
Keyword(s):  
Threshold Value ◽  
State Equation ◽  
Technical Condition ◽  
Complex Method ◽  
Technical Object ◽  
Common Information ◽  
Maintenance Practice ◽  
Condition Adjustment ◽  
Theoretical Foundations

A focus of the paper is concerned with the issue that optimal actions of regulation, diagnostics and reliability tests of technical objects are required from the maintenance staff involved in their use and servicing, and on the other hand, that they are performed independently and autonomously in the current maintenance practice instead of being accomplished in a strictly coordinated and complex way. It was noticed that only one and common information on the object exists and provides a solid basis for coordination of the regulation, diagnostics and reliability tests. This information can be applied many times for solving various problems no matter if they concern regulation, diagnostics or reliability. Next, this paper presents an original approach of conversion of the considered information into explicit time-and-space determined “number of threshold value overshoots” of signals related to the object and its environment as well as theoretical foundations (based on various configurations of the state equation) for conversion of the considered piece of information, expressed by the aforementioned “numbers”, into the parameters of the object ability condition (i.e., its technical condition, adjustment and reliability). The theses of the presented complex method for the assessment of technical object ability were subjected to long-term verification with positive result in the study of the Allison 250 engine bearing system.

Identification of Parametric and Momentary Damages on the Basis of Lindeberg-Levy’s Model

2017 ◽  
Vol 260 ◽  
pp. 249-257
Author(s):  
Paweł Lindstedt ◽  
Tomasz Sudakowski
Keyword(s):  
Standard Deviation ◽  
Threshold Value ◽  
Technical Condition ◽  
Technical Object ◽  
Reliability Parameters ◽  
Innovative Method ◽  
Condition Equation ◽  
Lévy’S Theorem ◽  
The Moment ◽  
Damage Map

Article presents the innovative method for the assessment of reliability condition of the exploited system, based on the appropriate analysis of changes in the current parameters of technical condition aRb and the regulation condition aRc, determined from the compressed condition equation (1 and 2). While analyzing the course of momentary parameters for technical condition aRb and the regulation condition aRc, it was observed that the parametric and momentary damages can be identified on the basis of quantitative relations between momentary threshold value dpr and corresponding momentary permissible value dprdop, which are calculated from equation (7, 8, 9) resulting from Lindeberg-Levy’s theorem. It is assumed that the damages are prevailing, when for the moment θi: dpri>dpr dopi. With the number of damages (damage map), reliability parameters for each moment of exploitation of technical object (before the catastrophic damages will occur) can be determined. Parametric damages (expected lifetime E(T) and standard deviation of expected lifetime σE(T) provides the reasonable information for the appropriate planning of the servicing of exploitative objects.

The Method of Assessment of Suitability of the Bearing System Based on Parameters of Technical and Adjustment State

2013 ◽  
Vol 199 ◽  
pp. 73-78 ◽  
Author(s):  
Paweł Lindstedt ◽  
Tomasz Sudakowski
Keyword(s):  
Threshold Value ◽  
Technical Condition ◽  
Complex Method ◽  
Technical Parameters ◽  
Coupled Equations ◽  
Operation Process ◽  
Regulatory Status ◽  
Method Of Assessment ◽  
Time Of Operation ◽  
Bearing System

In the operation process, a complex method evaluating technical condition and regulatory status (activities) of the bearing system is used. The method of determination of technical parameters and operating status is known. This is achieved through the interaction of two coupled equations and [2, 3, 7]. It was demonstrated that, on the basis of waveform parameters of technical condition and operating status (respectively), the identification of parametric and momentary damage can be carried out. During the identification process of parametric and momentary damage, it is assumed that damage arises when a parameter threshold value at the time of operation is greater than current permissible value. It is shown how the threshold value of the parameter and its current permissible value, taking into account the number of measurements, are determined.

scholarly journals The New Approach to Identification of Parametric and Momentary Damages on the Basis of Lindeberg – Levy’s Model

2017 ◽  
Vol 43 (1) ◽  
pp. 5-21
Author(s):  
Paweł Lindstedt ◽  
Tomasz Sudakowski ◽  
Artur Kułaszka
Keyword(s):  
Standard Deviation ◽  
Threshold Value ◽  
Technical Condition ◽  
Technical Object ◽  
New Approach ◽  
Reliability Parameters ◽  
Condition Equation ◽  
Lévy’S Theorem ◽  
The Moment ◽  
Damage Map

Abstract The new approach for the assessment of reliability condition of the exploited system, based on the appropriate analysis of changes in the current parameters of technical condition aRb and the regulation condition aRc, determined from the compressed condition equation (1 and 2). While analyzing the course of momentary parameters for technical condition aRb and the regulation condition aRc, it was observed that the parametric and momentary damages can be identified on the basis of quantitative relations between momentary threshold value dpr and corresponding momentary permissible value dpr dop, which are calculated from equation (7, 8, 9) resulting from Lindeberg–Levy’s theorem. It is assumed that the damages are prevailing, when for the moment θi: >dpri> dpr dopi. With the number of damages (damage map), reliability parameters for each moment of exploitation of technical object (before the catastrophic damages will occur) can be determined. Parametric damages (expected lifetime E(T) and standard deviation of expected lifetime σE(T) provides the reasonable information for the appropriate planning of the servicing of exploitative objects.

scholarly journals Automatic synchronisation of the cell cycle in budding yeast through closed-loop feedback control

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Giansimone Perrino ◽  
Sara Napolitano ◽  
Francesca Galdi ◽  
Antonella La Regina ◽  
Davide Fiore ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Autonomous Vehicles ◽  
Genetic System ◽  
Yeast Cells ◽  
Control Engineering ◽  
Loop Feedback ◽  
Experimental Approaches ◽  
Closed Loop Feedback ◽  
Theoretical Foundations

AbstractThe cell cycle is the process by which eukaryotic cells replicate. Yeast cells cycle asynchronously with each cell in the population budding at a different time. Although there are several experimental approaches to synchronise cells, these usually work only in the short-term. Here, we build a cyber-genetic system to achieve long-term synchronisation of the cell population, by interfacing genetically modified yeast cells with a computer by means of microfluidics to dynamically change medium, and a microscope to estimate cell cycle phases of individual cells. The computer implements a controller algorithm to decide when, and for how long, to change the growth medium to synchronise the cell-cycle across the population. Our work builds upon solid theoretical foundations provided by Control Engineering. In addition to providing an avenue for yeast cell cycle synchronisation, our work shows that control engineering can be used to automatically steer complex biological processes towards desired behaviours similarly to what is currently done with robots and autonomous vehicles.

أثر محددات الاستثمار في الاقتصاد العراقي للمدة (2004-2018) ، دراسة قياسية

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
مهند المحمدي ◽  
محمد الحياني
Keyword(s):  
Error Correction ◽  
Statistical Significance ◽  
Economic Thought ◽  
Explanatory Variables ◽  
Equilibrium Relationship ◽  
Cointegration Tests ◽  
Short And Long Term ◽  
Standard Models ◽  
Theoretical Foundations

The research aims to measure and analyze the determinants of investment in the Iraqi economy and study the theoretical foundations of investment and analyze the viewpoint of the most important schools of economic thought regarding investment and investment determinants and their effects on economic activity , and by using possible standard models as the results of standard analysis using the joint integration tests of time series . cointegration tests, they have proven the existence of a long-term equilibrium relationship according to the methodology of the results of estimating the short and long-term parameters and the error correction parameter(ECM) , it is moving from a set of explanatory variables towards The dependent variable, while the value of the error correction vector coefficient was negative and significant , as it reached (-0.59%) , which means the fulfillment of the two basic conditions in this parameter , namely : its negative value and the statistical significance . This means that (0.59) of the short-term errors are automatically corrected during the unit of time (year) to reach the equilibrium in the long term, meaning that the investment requires about less then a year (1.6) , that is , approximately a year and 6 days to reach its equilibrium value in the long term , In other words , the previous period deviates from the long-term equilibrium and is corrected in the current by (59%) . This indicates that the adjustment in the model was relatively fast .

scholarly journals Long-term analysis of clear-sky new particle formation events and non-events in Hyytiälä

2016 ◽  
Author(s):  
Lubna Dada ◽  
Pauli Paasonen ◽  
Tuomo Nieminen ◽  
Stephany Buenrostro Mazon ◽  
Jenni Kontkanen ◽  
...  
Keyword(s):  
Formation Rate ◽  
Threshold Value ◽  
Particle Formation ◽  
New Particle Formation ◽  
Organic Vapors ◽  
Clear Sky ◽  
Sky Conditions ◽  
Oxidized Products ◽  
Condensation Sink

Abstract. New particle formation (NPF) events have been observed all around the world and are known to be a major source of atmospheric aerosol particles. Here we combine 20 years of observations in a boreal forest at the SMEAR II station (Station for Measuring Ecosystem-Atmosphere Relations) in Hyytiälä, Finland, by utilizing previously accumulated knowledge, and by focusing on clear-sky (non-cloudy) conditions. We first investigated the effect of cloudiness on NPF and then compared the NPF event and non-event days during clear-sky conditions. In this comparison we considered, for example, the effects of calculated particle formation rates, condensation sink, trace gas concentrations and various meteorological quantities. The formation rate of 1.5 nm particles was calculated by using proxies for gaseous sulfuric acid and oxidized products of low volatile organic compounds. As expected, our results indicate an increase in the frequency of NPF events under clear-sky conditions. Also, focusing on clearsky conditions enabled us to find a clear separation of many variables related to NPF. For instance, oxidized organic vapors showed higher concentration during the clear-sky NPF event days, whereas the condensation sink (CS) and some trace gases had higher concentrations during the non-event days. The calculated formation rate of 3 nm particles showed a notable difference between the NPF event and non-event days during clear-sky conditions, especially in winter and spring. For spring time, we are able to find a threshold value for the combined values of ambient temperature and CS, above which practically no clear-sky NPF event could be observed. Finally, we present a probability distribution for the frequency of NPF events at a specific CS and temperature.

scholarly journals Cyber-yeast: Automatic synchronisation of the cell cycle in budding yeast through closed-loop feedback control

2020 ◽  
Author(s):  
Giansimone Perrino ◽  
Sara Napolitano ◽  
Francesca Galdi ◽  
Antonella La Regina ◽  
Davide Fiore ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Autonomous Vehicles ◽  
Genetic System ◽  
Yeast Cells ◽  
Control Engineering ◽  
Loop Feedback ◽  
Experimental Approaches ◽  
Closed Loop Feedback ◽  
Theoretical Foundations

ABSTRACTThe cell cycle is the process by which eukaryotic cells replicate. Yeast cells cycle asynchronously with each cell in the population budding at a different time. Although there are several experimental approaches to “synchronise” cells, these work only in the short-term. Here, we built a cyber-genetic system to achieve long-term synchronisation of the cell population, by interfacing genetically modified yeast cells with a computer by means of microfluidics to dynamically change medium, and a microscope to estimate cell cycle phases of individual cells. The computer implements a “controller” algorithm to decide when, and for how long, to change the growth medium to synchronise the cell-cycle across the population. Our work builds upon solid theoretical foundations provided by Control Engineering. In addition to providing a new avenue for yeast cell cycle synchronisation, our work shows that computers can automatically steer complex biological processes towards desired behaviours similarly to what is currently done with robots and autonomous vehicles.

scholarly journals A novel neural prosthesis providing long-term electrocorticography recording and cortical stimulation for epilepsy and brain-computer interface

2019 ◽  
Vol 130 (4) ◽  
pp. 1166-1179 ◽  
Author(s):  
Pantaleo Romanelli ◽  
Marco Piangerelli ◽  
David Ratel ◽  
Christophe Gaude ◽  
Thomas Costecalde ◽  
...  
Keyword(s):  
Nonhuman Primate ◽  
Large Scale ◽  
Brain Activity ◽  
Threshold Value ◽  
Time Span ◽  
Cortical Stimulation ◽  
Neural Prosthesis ◽  
Lower Limbs ◽  
Custom Made

OBJECTIVEWireless technology is a novel tool for the transmission of cortical signals. Wireless electrocorticography (ECoG) aims to improve the safety and diagnostic gain of procedures requiring invasive localization of seizure foci and also to provide long-term recording of brain activity for brain-computer interfaces (BCIs). However, no wireless devices aimed at these clinical applications are currently available. The authors present the application of a fully implantable and externally rechargeable neural prosthesis providing wireless ECoG recording and direct cortical stimulation (DCS). Prolonged wireless ECoG monitoring was tested in nonhuman primates by using a custom-made device (the ECoG implantable wireless 16-electrode [ECOGIW-16E] device) containing a 16-contact subdural grid. This is a preliminary step toward large-scale, long-term wireless ECoG recording in humans.METHODSThe authors implanted the ECOGIW-16E device over the left sensorimotor cortex of a nonhuman primate (Macaca fascicularis), recording ECoG signals over a time span of 6 months. Daily electrode impedances were measured, aiming to maintain the impedance values below a threshold of 100 KΩ. Brain mapping was obtained through wireless cortical stimulation at fixed intervals (1, 3, and 6 months). After 6 months, the device was removed. The authors analyzed cortical tissues by using conventional histological and immunohistological investigation to assess whether there was evidence of damage after the long-term implantation of the grid.RESULTSThe implant was well tolerated; no neurological or behavioral consequences were reported in the monkey, which resumed his normal activities within a few hours of the procedure. The signal quality of wireless ECoG remained excellent over the 6-month observation period. Impedance values remained well below the threshold value; the average impedance per contact remains approximately 40 KΩ. Wireless cortical stimulation induced movements of the upper and lower limbs, and elicited fine movements of the digits as well. After the monkey was euthanized, the grid was found to be encapsulated by a newly formed dural sheet. The grid removal was performed easily, and no direct adhesions of the grid to the cortex were found. Conventional histological studies showed no cortical damage in the brain region covered by the grid, except for a single microscopic spot of cortical necrosis (not visible to the naked eye) in a region that had undergone repeated procedures of electrical stimulation. Immunohistological studies of the cortex underlying the grid showed a mild inflammatory process.CONCLUSIONSThis preliminary experience in a nonhuman primate shows that a wireless neuroprosthesis, with related long-term ECoG recording (up to 6 months) and multiple DCSs, was tolerated without sequelae. The authors predict that epilepsy surgery could realize great benefit from this novel prosthesis, providing an extended time span for ECoG recording.

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