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Article
Publication date: 1 January 1991

Special attention will be given in this part to the process of decline, which is to be seen as antipodal to development, and which nowadays is all too often neglected. By…

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Abstract

Special attention will be given in this part to the process of decline, which is to be seen as antipodal to development, and which nowadays is all too often neglected. By “decline” we mean here the decline of a whole society. But this definition is not yet sufficient to provide us with a very clear understanding. The statement that a whole society is in decline remains void of real meaning until we possess some concrete conception of what a “whole society” and the process of “decline” are. Since the meanings of both these terms are problematical, further explanation and closer precision are called for.

Details

International Journal of Social Economics, vol. 18 no. 1/2/3
Type: Research Article
ISSN: 0306-8293

Article
Publication date: 1 December 2003

J. Gyselinck, P. Dular, L. Vandevelde, J. Melkebeek, A.M. Oliveira and P. Kuo‐Peng

An original and easy‐to‐implement method to take into account movement (motion) in the 2D harmonic balance finite element modelling of electrical machines is presented. The global…

Abstract

An original and easy‐to‐implement method to take into account movement (motion) in the 2D harmonic balance finite element modelling of electrical machines is presented. The global harmonic balance system of algebraic equations is derived by applying the Galerkin approach to both the space and time discretisation. The harmonic basis functions, i.e. a cosine and a sine function for each nonzero frequency and a constant function 1 for the DC component, are used for approximating the periodic time variation as well as for weighing the time domain equations in the fundamental period. In practice, this requires some elementary manipulations of the moving band stiffness matrix. Magnetic saturation and electrical circuit coupling are considered in the analysis as well. As an application example, the noload operation of a permanent‐magnet machine is considered. The voltage and induction waveforms obtained with the proposed harmonic balance method are shown to converge well to those obtained with time stepping.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 22 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 September 2004

Javad Dargahi and Siamak Najarian

This paper describes the design, fabrication, testing, and mathematical modeling of a supported membrane type polyvinylidene fluoride (PVDF) tactile sensor. Using the designed…

Abstract

This paper describes the design, fabrication, testing, and mathematical modeling of a supported membrane type polyvinylidene fluoride (PVDF) tactile sensor. Using the designed membrane type sensor (MTS), it is shown that the entire surface of the PVDF film can be employed as a means of detecting the force magnitude and its application point. This is accomplished by utilizing only three sensing elements. Unlike the array type tactile sensors, in which the regions between the neighboring sensing elements are not active, all the surface points of the sensor are practically active in this MTS. A geometric mapping process is introduced, thereby, the loci of the isocharge contours for the three sensing elements are determined by applying force on various points of the sensor surface. In order to form a criterion for the comparison between the experimental findings and the theoretical analysis data, and also to determine the magnitude of the stresses generated in the membrane, finite element modeling is used. The correlation between the theoretical predictions and experimental findings is proven to be reasonable. Potentially, the designed MTS can be incorporated into various medical probes for tactile imaging.

Details

Sensor Review, vol. 24 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 1 August 1977

C.A. Smith

Andrews, by 1887, had already made a significant contribution to the knowledge of corrosion science and at this time, decided to investigate the effect of magnetisation on the…

Abstract

Andrews, by 1887, had already made a significant contribution to the knowledge of corrosion science and at this time, decided to investigate the effect of magnetisation on the relative electrochemical position of a pair of bright iron bars, one magnetised by a coil, the other not magnetised, when simultaneously exposed in circuit to the action of various powerful oxidising agents and saline solutions.

Details

Anti-Corrosion Methods and Materials, vol. 24 no. 8
Type: Research Article
ISSN: 0003-5599

Book part
Publication date: 13 March 2012

Silvina Gvirtz and Betina Duarte

History in Argentina shows that, from 1945, rotation between democratic and de facto governments was accompanied with changes in policies of free or restricted university access…

Abstract

History in Argentina shows that, from 1945, rotation between democratic and de facto governments was accompanied with changes in policies of free or restricted university access, respectively. In this way after more than 20 years of democracy, 60 percent of the university matriculation of the public system stays under the modality of free access. Nevertheless, the socioeconomic composition of the students of public universities shows overrepresentation of the higher income quintiles. This means that the policies of free access to the public universities have been better taken advantage of by the population with major resources. However, the ideology of free access remains in the social imaginary as the representative of progress policies. In this chapter, we set out, first of all, to describe the admission system to the universities in Argentina. Second, we analyze the relationship between unrestricted access and equity. Finally, we will raise the necessity to design policies of affirmative action, for the case of Argentina and more likely in other countries of Latin America, that consider the asymmetries in the distribution of the wealth on the questions of race and gender.

Details

As the World Turns: Implications of Global Shifts in Higher Education for Theory, Research and Practice
Type: Book
ISBN: 978-1-78052-641-6

Keywords

Article
Publication date: 25 January 2021

Rekha Yoganathan, Jamuna Venkatesan and William Christopher I.

This paper intent to design, develop, and fabricate a robust cascaded controller based on the dual loop concept i.e. Fuzzy Sliding Mode concept in the inner loop and traditional…

Abstract

Purpose

This paper intent to design, develop, and fabricate a robust cascaded controller based on the dual loop concept i.e. Fuzzy Sliding Mode concept in the inner loop and traditional Proportional Integral controller in the outer loop to reduce the unknown dynamics and disturbances that occur in the DC-DC Converter.

Design/methodology/approach

The proposed Fuzzy sliding mode approach combines the merits of both SMC and Fuzzy logic control. FSMC approach reduces the chattering phenomena that commonly occurs in the sliding mode control and speed up the response of the controller.

Findings

In most of the research work, the inner current loop of cascaded controller was designed by sliding mode control. In this paper FSMC is proposed and its efficacy is confirmed with SMC -PI. In most uncertainties, FSMC-PI produces null maximum peak overshoot and a very less settling time of 0.0005 sec.

Originality/value

The presence of Fuzzy SMC in the inner loop ensure satisfactory response against all uncertainties such as steady state, circuit parameter variations and sudden line and load disturbances.

Details

Circuit World, vol. 48 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 29 April 2014

André Pohlmann and Kay Hameyer

Total artificial hearts (TAHs) are required for the treatment of cardiovascular diseases. In order to replace the native heart a TAH must provide a sufficient perfusion of the…

Abstract

Purpose

Total artificial hearts (TAHs) are required for the treatment of cardiovascular diseases. In order to replace the native heart a TAH must provide a sufficient perfusion of the human body, prevent blood damage and meet the implantation constraints. Until today there is no TAH on the market which meets all constraints. So the purpose of this paper is to design a drive in such a way that the operated TAH meets all predefined constraints.

Design/methodology/approach

The drive is designed in terms of weight and electric losses. In setting up a cost function containing those constraints, the drive design can be included in a optimization process. When reaching the global minimum of the cost function the optimum drive design is found. In this paper the optimization methods manual parameter variation and differential evolution are applied.

Findings

At the end of the optimization process the drive's weight amounts to 460 g and its mean losses sum up to 10 W. This design meets all predefined constraints. Further it is proposed to start the optimization process with a parameter variation to reduce the amount of optimization parameters for the time consuming differential evolution algorithm.

Practical implications

This TAH has the potential to provide a therapy for all patients suffering from cardiovascular diseases as it is independent of donor organs.

Originality/value

The optimization-based design process yields an optimum drive for a TAH in terms of weight and electrical losses. In this way a TAH is developed which meets all implantation constraints and provides sufficient perfusion of the human body at the same time.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 33 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 August 1915

Before the appearance of our next issue, the Annual Meeting of the Library Association will have taken place. In many ways, as indicated last month, it will be an interesting…

Abstract

Before the appearance of our next issue, the Annual Meeting of the Library Association will have taken place. In many ways, as indicated last month, it will be an interesting meeting, largely because it is in the nature of an experiment. International conditions, the state of national and municipal finance, the absence of library workers with the colours, and the omission of social events, all tend to influence its character. It is possible, however, that these very circumstances may increase the interest in the actual conference business, especially as the programme bears largely upon the War. The programme itself is formidable, and it will be interesting to see how the section on the literature of the war, for example, will be treated. Probably the Publications' Committee have in mind the book symposia which are a feature of the meetings of various library associations in the United States. These consist of a few minutes' characterisation, by an opener, of a certain book or type of literature, and a discussion after it. The experiment was attempted in London last year at one of the monthly meetings, but owing to a misapprehension the speaker gave an excellent lecture on Francis Thompson of more than an hour's duration, when he had been expected to give a brief description of Francis Meynell's biography of that poet. If any gatherings for a similar purpose are arranged, we hope the speakers will be primed sufficiently to avoid that error. As for social events, their omission is less likely to be felt in London than anywhere else in the Kingdom. London is a perennial source of social amusement in itself, and the evenings can readily be filled there—“chacun à son goût”—really better than by attending pre‐arranged gatherings.

Details

New Library World, vol. 18 no. 2
Type: Research Article
ISSN: 0307-4803

Article
Publication date: 1 September 2003

J. Gyselinck, P. Dular, W. Legros and D. Grenier

This paper deals with the modelling of transformer supply in the two‐dimensional (2D) finite element (FE) simulation of rotating electrical machines. Three different transformer…

Abstract

This paper deals with the modelling of transformer supply in the two‐dimensional (2D) finite element (FE) simulation of rotating electrical machines. Three different transformer models are compared. The reference one is based on two 2D FE models, considering a cross‐section either parallel or perpendicular to the laminations of the magnetic core. The parameters of the two other transformer models, a magnetic equivalent circuit and an electrical equivalent circuit, can be derived from the reference model. Particular attention is paid to some common features of the transformer models, e.g. with regard to the inclusion of iron losses. The three models are used in the 2D FE simulation of the steady‐state load operation and the starting from stand‐still of an induction motor.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 22 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Abstract

Details

Visual Pollution
Type: Book
ISBN: 978-1-80382-042-2

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