Space Sampling Effects in Nonlinear Distributed System Stability

1981 ◽  
Vol 103 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Guy Jumarie
Keyword(s):  
Distributed Control ◽  
Distributed System ◽  
Absolute Stability ◽  
Transfer Functions ◽  
Point Of View ◽  
System Stability ◽  
Distributed Parameter ◽  
Practical Point ◽  
Output Stability ◽  
Constant Coefficients

The purpose of this paper is to determine, from a practical point of view, the effects of a space sampling on the input-output stability, and the absolute stability of distributed parameter systems with distributed control. Three models are proposed which involve, respectively, transfer functions in space and time, Laplace-Green’s functions, and distributed transfer functions. It is shown that the first model is the most pessimistic, but in contrast is the easiest to use. While the first model applies to system with constant coefficients only, the other ones can be used with constant or space dependent coefficients.

Analyze a Feedback System with the R-H Stability Criterion

2014 ◽  
Vol 496-500 ◽  
pp. 1698-1701
Author(s):  
Ying Sun ◽  
Wei Yan
Keyword(s):  
Stability Analysis ◽  
Control Systems ◽  
Absolute Stability ◽  
Closed Loop ◽  
Feedback System ◽  
Point Of View ◽  
Practical Point ◽  
Loop Feedback ◽  
Closed Loop Feedback ◽  
The Right

From a practical point of view, a closed-loop feedback system that is unstable is of little value. Many control systems are subject to extraneous disturbance signals that cause the system to provide an inaccurate output. The Routh-Hurwitz criterion ascertains the absolute stability of a system by determining whether any of the roots of the characteristic equation lie in the right half of the s-plane. This study concludes with a stability analysis based on the Routh-Hurwitz method.

Input-Output Stability Criteria for a Broad Class of Stochastic Nonlinear Distributed Systems Defined by Green’s Function

1975 ◽  
Vol 97 (1) ◽  
pp. 83-91 ◽  
Author(s):  
G. Jumarie
Keyword(s):  
Distributed Systems ◽  
Transfer Functions ◽  
Broad Class ◽  
Linear Part ◽  
Point Of View ◽  
Feedback Gain ◽  
Stability Criteria ◽  
Nonlinear Feedback ◽  
Input Output ◽  
Output Stability

This paper deals with the input-output stability of a class of nonlinear distributed systems defined by their Laplace-Green’s functions, or similarly from a practical point of view, by their distributed transfer functions. The time dependent nonlinear feedback element is distributed and bounded by two limiting gains which depend explicitly upon the distributed parameter. These systems are disturbed by a state and space dependent Gaussian noise which is added to the input of their linear components. This noise depends explicitly upon the output of the system via its own nonlinear feedback gain. Some input-output stability criteria are stated, which can be considered as being stochastic distributed versions of the circle criterion available for deterministic lumped parameter systems. They involve the stochastic mean square norm and they are expressed in term of the relative positions, in the complex plane, of a circle which depends upon the nonlinearities and the variance of the noise on the one hand; and a locus which may be interpreted as being the Nyquist locus of the linear part on the other hand.

Tertiary Nitrification Pilot Plants on Parisian Waste Water

1990 ◽  
Vol 22 (1-2) ◽  
pp. 347-352 ◽  
Author(s):  
C. Paffoni ◽  
B. Védry ◽  
M. Gousailles
Keyword(s):  
Waste Water ◽  
Metropolitan Area ◽  
Fixed Bed ◽  
Point Of View ◽  
Operating Conditions ◽  
Research Center ◽  
Daily Output ◽  
Practical Point ◽  
Fixed Bed Reactors

The Paris Metropolitan area, which contains over eight million inhabitants, has a daily output of about 3 M cu.meters of wastewater, the purification of which is achieved by SIAAP (Paris Metropolitan Area Sewage Service) in both Achères and Valenton plants. The carbon pollution is eliminated from over 2 M cu.m/day at Achères. In order to improve the quality of output water, its tertiary nitrification in fixed-bed reactors has been contemplated. The BIOFOR (Degremont) and BIOCARBONE (OTV) processes could be tested in semi-industrial pilot reactors at the CRITER research center of SIAAP. At a reference temperature of 13°C, the removed load is approximately 0.5 kg N NH4/m3.day. From a practical point of view, it may be asserted that in such operating conditions as should be at the Achères plant, one cubic meter of filter can handle the tertiary nitification of one cubic meter of purified water per hour at an effluent temperature of 13°C.

scholarly journals On the Design of Outdoor Leader-Follower UAV-Formation Controllers from a Practical Point of View

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Lucas Vago Santana ◽  
Alexandre Santos Brandao ◽  
Mario Sarcinelli-Filho
Keyword(s):  
Point Of View ◽  
Practical Point

scholarly journals Vibroacoustic Assessment of an Innovative Composite Material for the Roof of a Coupe Car

2021 ◽  
Vol 11 (3) ◽  
pp. 1128
Author(s):  
Nunziante Cascone ◽  
Luca Caivano ◽  
Giuseppe D’Errico ◽  
Roberto Citarella
Keyword(s):  
Composite Material ◽  
Transfer Functions ◽  
Realistic Model ◽  
Point Of View ◽  
Damping Capacity ◽  
Geometry Structure ◽  
Fiberglass Composite ◽  
New Material ◽  
Static Rigidity ◽  
Innovative Material

The objective of this paper is the vibroacoustic evaluation of an innovative material for a sports car roof, aiming at replacing fiberglass composite materials. Such evaluation was carried out using numerical and experimental analysis techniques, with cross-comparison between the corresponding results. The innovative material under analysis is a composite material, with a thermoplastic polypropylene matrix and reinforcement made of cellulose fibers. In order to validate the virtual dynamic modeling of the new material, the inertance on different points of some sheets made of the material under analysis was evaluated by an in-house made experimental activity, performed in the CRF (Fiat Research Center) test room, and cross-compared with corresponding results from a numerical analysis performed with the MSC Nastran software. Then, a realistic model of the car roof of the Alfa Romeo 4C car, made with the new material, was implemented and analyzed from the vibroacoustic point of view. The mere switch to the new material, with no changes in the geometry/structure of the car roof, did not allow preserving the original values of static rigidity, dynamic rigidity, and configuration of modal shapes. For this reason, a geometric/structural optimization of the component was performed. Once the new geometry/structure was defined, a vibroacoustic analysis was carried out, checking for a possible coupling between the fluid cavity modes and the structure car body modes. Finally, the vibroacoustic transfer functions to the driver’s ear node were assessed, considering two different excitation points on the structure. The excellent damping capacity of the proposed material led to an improvement in the vibroacoustic transfer functions and to a reduction in the weight of the pavilion.

Quantitative Analysis of Microstructure and Modeling of Sintering

2009 ◽  
Vol 624 ◽  
pp. 1-18 ◽  
Author(s):  
Jean Marc Chaix
Keyword(s):  
Image Analysis ◽  
Input Data ◽  
3D Imaging ◽  
Point Of View ◽  
Size Distributions ◽  
Practical Point ◽  
The Past ◽  
Modeling Techniques ◽  
Mean Size ◽  
Sintering Mechanisms

Microstructure is the key scale to understand and describe sintering mechanisms and their consequences at the macroscopic level. As modeling techniques are continuously developing, the need for input data and comparison with more and more accurate descriptions of the evolution is expected to create a growing demand for quantitative microstructure data. Image analysis is the classic way to get these data. This paper reviews the practical use and progresses of this old technique in the sintering literature during the past and recent years. The place of basic tools and more recent ones, such as 3D imaging, are discussed from a practical point of view accounting from sintering models needs: mean size and size distributions in pores and grains, homogeneity, sintering trajectories…

Technology and the management imagination

2005 ◽  
Vol 13 (3) ◽  
pp. 533-563 ◽  
Author(s):  
Fred Phillips
Keyword(s):  
Corporate Culture ◽  
Point Of View ◽  
Local Culture ◽  
Social Consensus ◽  
Practical Point ◽  
Research Questions ◽  
Crisis Managers

This paper explores the evolution of the techno-management imagination (TMI). This is the process by which, in times of crisis, managers think not just out of the box, but out of the very reality in which the box resides. Tacit social consensus, also known as corporate culture, can lead to a shared, implicit, and incorrect view that certain actions are impossible. TMI transcends local culture, accessing technological solutions that are unknown and/or unimagined. Members of the organization tend to call such solutions “magic”. The paper looks at social, perceptual, and managerial aspects of magic from a practical point of view that is grounded in research. It examines the risks of TMI, and concludes with suggested perspectives and research questions for management scientists and cognitive scientists.

Towards a New Model of Conversion Careers: the Impact of Personality and Contingency Factors

Exchange ◽  
2005 ◽  
Vol 34 (2) ◽  
pp. 149-166 ◽  
Author(s):  
Henri Gooren
Keyword(s):  
Religious Conversion ◽  
Religious Affiliation ◽  
Point Of View ◽  
Small Scale ◽  
Central Question ◽  
Roman Catholicism ◽  
Guatemala City ◽  
Practical Point ◽  
The Poor ◽  
The Impact

AbstractThe central question of this article — why people may change their religious affiliation or become disaffiliated — is relevant from both an academic and a practical point of view. The article makes first an inventory of existing literature on religious conversion. Next I sketch the contours of the new conversion careers approach I am currently working on. I make some comparisons with a region that is not usually mentioned in the literature on conversion: Latin America. These comparisons are based on my earlier fieldwork on Roman Catholicism, Pentecostalism, and Mormonism in Costa Rica and Guatemala (H. Gooren, Rich among the Poor: Church, Firm, and Household among Small-scale Entrepreneurs in Guatemala City, Amsterdam: Thela Thesis 1999).

DURATION OF ACARICIDAL ACTION OF THE DRUG «KENEM» AND ECONOMIC JUSTIFICATION FOR THE PROTECTION OF CATTLE FROM IXODIC MITES

Habarshy ◽  
2021 ◽  
pp. 50-60
Author(s):  
A.B. Myrzhiyeva ◽  
M.Zh Suleimenov ◽  
Uslu Ugur ◽  
A.S. Ibazhanova ◽  
L.O Zhanteliyeva L.O
Keyword(s):  
Economic Feasibility ◽  
Point Of View ◽  
Scientific Article ◽  
Special Equipment ◽  
Practical Point ◽  
Acaricidal Efficacy ◽  
Economic Justification ◽  
Long Duration ◽  
Similar Drug ◽  
The Cost

The scientific article presents the duration of acaricidal effect of «Kenem» drug, and its economic feasibility for protecting cattle against ixodic ticks. As a result of the study, the acaricidal efficacy and the duration of the residual acaricidal effect of drugs are important components in the planning of anti-tick measures. From a practical point of view, the economic feasibility of treating cattle against ixodic ticks in the presented conditions of acaricides in the southern regions is considered important. Despite the fact that the cost of the drug per 100 head exceeds the cost of a similar drug by 1 788.15 tenge, the frequency of its use is less, and additional installations are not required. This is due to the long duration of residual acaricidal effect of Kenem, which is 30 days, which allows to reduce the number of therapeutic measures.When calculating the economic feasibility for the use of acaricides to protect cattle against ixodic ticks, the most convenient way to prevent the sucking of ixodic ticks to animals is the local application of Kenem, which does not require special equipment and special skills of technical staff. Drug duration is 30 days, therefore the cost of its use for the entire season of active ticks per 1 animal is 44% cheaper, compared to veteran, i.e. 1,421.4 tenge.

ERRORS CONVERSION ON TRANSFER FUNCTIONS OF MEASUREMENT AND CONTROL

2021 ◽  
Vol 4 ◽  
pp. 92-104
Author(s):  
Valentin Bahatskyi ◽  
◽  
Aleksey Bahatskyi ◽  
Keyword(s):  
Transfer Functions ◽  
Systematic Errors ◽  
Step Function ◽  
Control Device ◽  
Point Of View ◽  
Correct Operation ◽  
Analog To Digital ◽  
Analog To Digital Conversion ◽  
And Control ◽  
Measurement And Control

Currently, the measurement of electrical and non-electrical quantities is performed using analog-to-digital conversion channels, which consist of analog signal conditioning circuits and analog-to-digital converters (ADC) of electrical quantities into a digital code. The paper considers the case when the defining errors of the measurement and control channel are systematic errors of the ADC. The reliability of measurements is assessed by their errors, and the reliability of control - by the likelihood of correct operation of the control device. In our opinion, evaluating the reliability of such similar processes as measurement and control using different criteria seems illogical. The aim of the work is to study the effect of systematic errors of an analog-to-digital converter on the errors of parameter control depending on the type of conformity functions and the width of the control window, as well as the choice of the resolution of the ADC for various control tasks. The paper analyzes the transfer functions of measurement and control. It is shown that they are formed using step functions. It is proposed to use not a step function as a control transfer function, but other functions of conformity to the norm, for example, a linear function or functions of higher orders. In this case, the control result is assessed not according to the criterion of the probability of correct operation, but using the control error. Analyzed from the point of view of reconfiguring the errors of the line, parabolic and state parabolic functions of the norms for the development of changes windows in control. A recommendation has been given for the selection of functions for the conformity of standards and for the distribution of analog-to-digital conversions for industrial control enterprises.

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