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Open Access
Article
Publication date: 22 March 2022

Hong Zhang and Tianlin Chen

The purpose of the study is to obtain and analyze vibro-acoustic characteristics.

Abstract

Purpose

The purpose of the study is to obtain and analyze vibro-acoustic characteristics.

Design/methodology/approach

A unified analysis model for the rotary composite laminated plate and conical–cylindrical double cavities coupled system is established. The related parameters of the unified model are determined by isoparametric transformation. The modified Fourier series are applied to construct the admissible displacement function and the sound pressure tolerance function of the coupled systems. The energy functional of the structure domain and acoustic field domain is established, respectively, and the structure–acoustic coupling potential energy is introduced to obtain the energy functional. Rayleigh–Ritz method was used to solve the energy functional.

Findings

The displacement and sound pressure response of the coupled systems are acquired by introducing the internal point sound source excitation, and the influence of relevant parameters of the coupled systems is researched. Through research, it is found that the impedance wall can reduce the amplitude of the sound pressure response and suppress the resonance of the coupled systems. Besides, the composite laminated plate has a good noise reduction effect.

Originality/value

This study can provide the theoretical guidance for vibration and noise reduction.

Details

Journal of Intelligent Manufacturing and Special Equipment, vol. 3 no. 1
Type: Research Article
ISSN: 2633-6596

Keywords

Article
Publication date: 31 May 2011

Marie de Rochambeau, Mohamed Ichchou and Bernard Troclet

The purpose of this paper is to extend statistical energy analysis (SEA)‐like modeling to fluid‐structure coupled systems.

Abstract

Purpose

The purpose of this paper is to extend statistical energy analysis (SEA)‐like modeling to fluid‐structure coupled systems.

Design/methodology/approach

An equivalent approach of aerodynamic loads is applied to a SEA‐like modeling of a panel‐cavity coupled system with rain‐on‐the‐roof excitation. Two aerodynamic excitations are presented: turbulent boundary layer (TBL) and diffuse field excitation. The energetic description of the coupled system is studied with both aerodynamic excitations, taking in account the coincidence effects. In order to extent the approach to more general systems, some parameters of the coupled system are also modified and the accuracy of the coupled system modeling is investigated.

Findings

The boundary conditions of the panel and the coupling strength between the panel and the cavity have been modified. As it was expected, the accuracy of equivalent approach is shown to be independent of such modifications. The interest of such calculation is thus highlighted: modelings of systems and aerodynamic excitations are independent, and can be treated separately.

Originality/value

This result is interesting in the space industry, for launch vehicles are excited by different types of random excitations. Those excitations can be modeled by SEA‐like with low calculation time and memory and applied to a unique system modeling.

Details

Engineering Computations, vol. 28 no. 4
Type: Research Article
ISSN: 0264-4401

Keywords

Book part
Publication date: 31 July 2020

Rita Berggren, Johanna E. Pregmark, Tobias Fredberg and Björn Frössevi

The literature on organizational change has long acknowledged the need to balance stability and economic efficiency with the need to be flexible and to change. Authors, certainly…

Abstract

The literature on organizational change has long acknowledged the need to balance stability and economic efficiency with the need to be flexible and to change. Authors, certainly in the dynamic capabilities tradition but also in other perspectives, have stressed the importance of more open and loosely coupled systems to promote adaption. However, many organizations do not operate on such premises but rather rely on creating efficient business units through tight coupling, building strict social and administrative control, and jointly relying on common systems. In this study, we conduct 46 interviews with employees from three different retail organizations to investigate how units in such tightly coupled systems change within the framework of the set standards. Through contrasting the characteristics of high and low functioning units, we identify three mechanisms that seem to enable the units to successfully and repeatedly realign and establish new configurations. We conclude that the orchestrator of all three realignment mechanisms is the middle manager, and we discuss the middle manager's role and the different activities that enable a successful realignment.

Details

Research in Organizational Change and Development
Type: Book
ISBN: 978-1-83909-083-7

Keywords

Article
Publication date: 1 December 1997

Ioannis St Doltsinis

Addresses problems in mechanics and physics involving two or more coupled variables of different nature, or a number of distinct domains which interact. For these kinds of…

Abstract

Addresses problems in mechanics and physics involving two or more coupled variables of different nature, or a number of distinct domains which interact. For these kinds of problems, considers numerical solution by the coupling of operators appertaining to the individual participating phenomena, or defined in the domains. Reviews the co‐operation of distinct discretized operators in connection with the integration of temporal evolution processes, and the iterative treatment of stationary equations of state. The specification of subtasks complies with the demand for an independent treatment on different processing units arising in parallel computation. Physical subtasks refer to problems of different field variables interacting on the continuum level; their number is usually small. Fine granularity may be achieved by separating the problem region into subdomains which communicate via the boundaries. In multiphysics simulations operators are preferably combined such that subdomains are processed in parallel on different units, while physical phenomena are processed sequentially in the subdomain.

Details

Engineering Computations, vol. 14 no. 8
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 5 October 2015

Sez Atamturktur and Ismail Farajpour

Physical phenomena interact with each other in ways that one cannot be analyzed without considering the other. To account for such interactions between multiple phenomena…

Abstract

Purpose

Physical phenomena interact with each other in ways that one cannot be analyzed without considering the other. To account for such interactions between multiple phenomena, partitioning has become a widely implemented computational approach. Partitioned analysis involves the exchange of inputs and outputs from constituent models (partitions) via iterative coupling operations, through which the individually developed constituent models are allowed to affect each other’s inputs and outputs. Partitioning, whether multi-scale or multi-physics in nature, is a powerful technique that can yield coupled models that can predict the behavior of a system more complex than the individual constituents themselves. The paper aims to discuss these issues.

Design/methodology/approach

Although partitioned analysis has been a key mechanism in developing more realistic predictive models over the last decade, its iterative coupling operations may lead to the propagation and accumulation of uncertainties and errors that, if unaccounted for, can severely degrade the coupled model predictions. This problem can be alleviated by reducing uncertainties and errors in individual constituent models through further code development. However, finite resources may limit code development efforts to just a portion of possible constituents, making it necessary to prioritize constituent model development for efficient use of resources. Thus, the authors propose here an approach along with its associated metric to rank constituents by tracing uncertainties and errors in coupled model predictions back to uncertainties and errors in constituent model predictions.

Findings

The proposed approach evaluates the deficiency (relative degree of imprecision and inaccuracy), importance (relative sensitivity) and cost of further code development for each constituent model, and combines these three factors in a quantitative prioritization metric. The benefits of the proposed metric are demonstrated on a structural portal frame using an optimization-based uncertainty inference and coupling approach.

Originality/value

This study proposes an approach and its corresponding metric to prioritize the improvement of constituents by quantifying the uncertainties, bias contributions, sensitivity analysis, and cost of the constituent models.

Details

Engineering Computations, vol. 32 no. 7
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 December 2002

Lance D. Fusarelli

This article examines the loosely coupled nature of the US educational system and explores recent systemic reform initiatives designed to improve education through more tightly…

3894

Abstract

This article examines the loosely coupled nature of the US educational system and explores recent systemic reform initiatives designed to improve education through more tightly coupled education policy and practice. The utility and limitations of loose coupling as an organizational construct are examined and critiqued. A number of significant forces are exerting ever‐greater pressure on policymakers to more tightly couple US education, including environmental pressures, the emergence of powerful new institutional actors, an emergent institutional capacity, and institutional isomorphism. After reviewing the effectiveness of systemic reform initiatives in several states, the article concludes that education in the USA is moving toward a system of fragmented centralization in which policymakers have greater opportunity to craft more coherent, systemic education policy amidst competing demands for limited resources.

Details

Journal of Educational Administration, vol. 40 no. 6
Type: Research Article
ISSN: 0957-8234

Keywords

Article
Publication date: 10 April 2007

G.B. Kumbhar, S.V. Kulkarni, R. Escarela‐Perez and E. Campero‐Littlewood

This paper aims to give a perspective about the variety of techniques which are available and are being further developed in the area of coupled field formulations, with selective…

1219

Abstract

Purpose

This paper aims to give a perspective about the variety of techniques which are available and are being further developed in the area of coupled field formulations, with selective bibliography and practical examples, to help postgraduate students, researchers and designers working in design or analysis of electrical machinery.

Design/methodology/approach

This paper reviews the recent trends in coupled field formulations. The use of these formulations for designing and non‐destructive testing of electrical machinery is described, followed by their classifications, solutions and applications. Their advantages and shortcomings are discussed.

Findings

The paper gives an overview of research, development and applications of coupled field formulations for electrical machinery based on more than 160 references. All landmark papers are classified. Practical engineering case studies are given which illustrate wide applicability of coupled field formulations.

Research limitations/implications

Problems which continue to pose challenges to researchers are enumerated and the advantages of using the coupled‐field formulation are pointed out.

Practical implications

This paper gives a detailed description of the application of the coupled field formulation method to the analysis of problems that are present in different electrical machines. Examples of analysis of generators and transformers with this formulation are presented. The application examples give guidelines for its use in other analyses.

Originality/value

The coupled‐field formulation is used in the analysis of rotational machines and transformers where reference data are available and comparisons with other methods are performed and the advantages are justified. This paper serves as a guide for the ongoing research on coupled problems in electrical machinery.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 26 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 3 May 2013

Clive Dimmock and Cheng Yong Tan

While Singapore's outstanding educational achievements are well known worldwide, there is a disproportionate paucity of literature on school leadership practices that contribute…

3739

Abstract

Purpose

While Singapore's outstanding educational achievements are well known worldwide, there is a disproportionate paucity of literature on school leadership practices that contribute to and support pedagogical initiatives that – along with socio‐cultural factors – are normally considered responsible for its educational success. The aim of this paper is to explicate system‐wide school leadership factors that contribute to Singapore's educational success.

Design/methodology/approach

The paper includes critical discussion, review of literature and conceptualization.

Findings

It is argued that three unique features of Singapore school leadership, namely – logistics of a small tightly‐coupled school system, human resource policies that reinforce alignment, and a distinctive “leader‐teacher compact” reflecting the predominant Chinese culture – account for the extraordinary level of tight coupling and alignment of leadership across the school system. In turn, these unique features bring synergies of sustainability, scalability, succession, and high performance across the entire Singapore school system.

Research limitations/implications

Unique features of Singapore school leadership must be examined in conjunction with pedagogical initiatives and socio‐cultural factors for a more complete and nuanced understanding of educational success in Singapore.

Practical implications

Tightly coupled mechanisms of leadership underlie the success of Singapore education. Government needs to consider whether such tightly‐ coupled leadership will continue to serve it well in future, given the demand for twenty‐first century knowledge based skills.

Social implications

The influence of socio‐cultural factors (e.g. leader‐teacher compact) on educational success merits inclusion in any explanation.

Originality/value

This paper addresses an important gap in the literature by promulgating crucial features of school leadership that contribute to Singapore's educational success.

Details

Journal of Educational Administration, vol. 51 no. 3
Type: Research Article
ISSN: 0957-8234

Keywords

Book part
Publication date: 9 July 2010

Donald Palmer and Michael Maher

We use normal accident theory to analyze the financial sector, especially that part of the financial sector that processed home mortgages, and the mortgage meltdown. We maintain…

Abstract

We use normal accident theory to analyze the financial sector, especially that part of the financial sector that processed home mortgages, and the mortgage meltdown. We maintain that the financial sector was highly complex and tightly coupled in the years leading up to the mortgage meltdown. And we argue that the meltdown exhibited characteristics of a system or normal accident; the result of a component failure (unusually high mortgage defaults) that, in the context of unique conditions (which included low interest rates and government policy encouraging home loans to less credit-worthy households), resulted in complex and tightly coupled interactions that financial elites and government officials were ill-equipped to control. We also consider the role that agency and wrongdoing played in the design of the financial system and the unfolding of the mortgage meltdown. We conclude that a fundamental restructuring of the financial system, so as to reduce complexity and coupling, is required to avert future similar financial debacles. But we also conclude that such a restructuring faces significant obstacles, given the interests of powerful actors and the difficulties of labeling those responsible for the meltdown as wrongdoers.

Details

Markets on Trial: The Economic Sociology of the U.S. Financial Crisis: Part A
Type: Book
ISBN: 978-0-85724-205-1

Article
Publication date: 1 December 2002

Brian Rowan

In this paper, I argue that ideas about loose coupling can serve a useful purpose in organization theory, but only if they are re‐worked substantially. This re‐working, I argue…

1263

Abstract

In this paper, I argue that ideas about loose coupling can serve a useful purpose in organization theory, but only if they are re‐worked substantially. This re‐working, I argue, will involve merging ideas about loose coupling with ideas found in other lines of work developed contemporaneously, including research on the “new” managerialism, institutional theory, and organizational ecology. Such a re‐working, I hope, will entail closer attention to the elements in educational systems that can be coupled and to an expanded list of coupling mechanisms. Using this expanded list of coupling mechanisms, and thinking more clearly about how educational organizations are embedded in dense and complex webs of couplings calls for a movement away from an exclusive concern with loose and tight couplings among dyadic elements in organizational systems, and toward a concern with “tangled” couplings.

Details

Journal of Educational Administration, vol. 40 no. 6
Type: Research Article
ISSN: 0957-8234

Keywords

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