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Article
Publication date: 13 August 2019

Hui Lü, Kun Yang, Wen-bin Shangguan, Hui Yin and DJ Yu

The purpose of this paper is to propose a unified optimization design method and apply it to handle the brake squeal instability involving various uncertainties in a…

Abstract

Purpose

The purpose of this paper is to propose a unified optimization design method and apply it to handle the brake squeal instability involving various uncertainties in a unified framework.

Design/methodology/approach

Fuzzy random variables are taken as equivalent variables of conventional uncertain variables, and a unified response analysis method is first derived based on level-cut technique, Taylor expansion and central difference scheme. Next, a unified reliability analysis method is developed by integrating the unified response analysis and fuzzy possibility theory. Finally, based on the unified reliability analysis method, a unified reliability-based optimization model is established, which is capable of optimizing uncertain responses in a unified way for different uncertainty cases.

Findings

The proposed method is extended to perform squeal instability analysis and optimization involving various uncertainties. Numerical examples under eight uncertainty cases are provided and the results demonstrate the effectiveness of the proposed method.

Originality/value

Most of the existing methods of uncertainty analysis and optimization are merely effective in tackling one uncertainty case. The proposed method is able to handle the uncertain problems involving various types of uncertainties in a unified way.

Details

Engineering Computations, vol. 37 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 28 December 2020

Can-Zhong Yao and Yi-Na Mo

The purpose of this paper is to whether competition between platforms can be effective, thus leading to efficient allocations.

Abstract

Purpose

The purpose of this paper is to whether competition between platforms can be effective, thus leading to efficient allocations.

Design/methodology/approach

Based on the classic linear Hoteling model, this paper builds a two-period competition model for two competing platforms using two variants, namely, a discrimination pricing model and a unified pricing model.

Findings

In the case of the discrimination pricing model, the competition is moderate, and the two platforms split the market evenly in the first stage, while both platforms tended to offer preferential treatment to new users and set higher prices for regular customers in the second stage. Compared to the unified pricing model, in the first stage, the platform can provide a higher price that depends on the cross-network effect when it implements discrimination, and thus, obtains higher profits. However, in the second stage, fierce competition leads to the release of benefits, new and regular customers obtain lower prices and the platforms lose higher profits. In the long-run, discriminatory pricing is not the best option due to lower total profits. The two platforms will implement cooperative pricing or one platform becomes dominant.

Originality/value

Instead of focusing on the cross-network effects, this paper emphasizes the role of the same-side network effect on price discrimination regarding the platforms’ competition. The same-side network effects are investigated in relation to a discrimination pricing strategy and compared to a unified pricing strategy. Another innovative aspect is the study of these network effects in a dynamic setting based on a two-period competition model for two platforms.

Details

Kybernetes, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0368-492X

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Article
Publication date: 8 May 2018

Aibin Zhu, Hongling Wu, Yulei Yang and Shengli He

Because of the various geometric descriptions of different bearing types, performance calculation of journal bearing is complicated, and is difficult in traditional model

Abstract

Purpose

Because of the various geometric descriptions of different bearing types, performance calculation of journal bearing is complicated, and is difficult in traditional model. This paper aims to simplify the calculation of the journal bearing performance, and to reduce the workload.

Design/methodology/approach

On the basis of previous research, a general performance calculation model of journal bearing is proposed in this paper. Eccentricity ratio and attitude angle of axis to each pad are calculated by coordinates of spindle center and each pad center by establishing the unified coordinate system. The surface deformation of journal bearing is taken into consideration, and a correction value is added to the dimensionless oil film thickness.

Findings

The performance calculation results of various fix-pad and tilting-pad journal bearings match the results of the existing references very well, revealing the validity of the model. The general model can greatly reduce programming workload, and increase adaptability to different bearings.

Originality/value

Geometric descriptions of both fix-pad and tilting-pad journal bearings are unified in this model, which can be applied to both standard and non-standard journal bearings with different preload ratios. In addition, due to the unification of different bearings types, this model is more conducive to performance comparison among different bearing types, and promotes the development of new structural forms for journal bearings.

Details

Industrial Lubrication and Tribology, vol. 70 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 March 1989

V.K. Arya and A. Kaufman

A description of the finite element implementation of Robinson's unified viscoplastic model into the general purpose finite element program, MARC, is presented. To…

Abstract

A description of the finite element implementation of Robinson's unified viscoplastic model into the general purpose finite element program, MARC, is presented. To demonstrate its application, the implementation is applied to some uniaxial and multiaxial problems. A comparison of the results for the multiaxial problem of a thick internally pressurized cylinder, obtained using the finite element implementation and an analytical solution, is also presented. Excellent agreement obtained confirms the correct finite element implementation of Robinson's model.

Details

Engineering Computations, vol. 6 no. 3
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 24 June 2021

Chuanyuan Zhou, Zhenyu Liu, Chan Qiu and Jianrong Tan

The purpose of this paper is to propose a novel mathematical model to present the three-dimensional tolerance of a discrete surface and to carry out an approach to analyze…

Abstract

Purpose

The purpose of this paper is to propose a novel mathematical model to present the three-dimensional tolerance of a discrete surface and to carry out an approach to analyze the tolerance of an assembly with a discrete surface structure. A discrete surface is a special structure of a large surface base with several discrete elements mounted on it, one, which is widely used in complex electromechanical products.

Design/methodology/approach

The geometric features of discrete surfaces are separated and characterized by small displacement torsors according to the spatial relationship of discrete elements. The torsor cluster model is established to characterize the integral feature variation of a discrete surface by integrating the torsor model. The influence and accumulation of the assembly tolerance of a discrete surface are determined by statistical tolerance analysis based on the unified Jacobian-Torsor method.

Findings

The effectiveness and superiority of the proposed model in comprehensive tolerance characterization of discrete surfaces are successfully demonstrated by a case study of a phased array antenna. The tolerance is evidently and intuitively computed and expressed based on the torsor cluster model.

Research limitations/implications

The tolerance analysis method proposed requires much time and high computing performance for the calculation of the statistical simulation.

Practical implications

The torsor cluster model achieves the three-dimensional tolerance representation of the discrete surface. The tolerance analysis method based on this model predicts the accumulation of the tolerance of components before their physical assembly.

Originality/value

This paper proposes the torsor cluster as a novel mathematical model to interpret the tolerance of a discrete surface.

Details

Assembly Automation, vol. 41 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 1 August 2000

Z.N. Cheng, G.Z. Wang, L. Chen, J. Wilde and K. Becker

A viscoplastic constitutive model, the Anand model, in which plasticity and creep are unified and described by the same set of flow and evolutionary relations, was applied…

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Abstract

A viscoplastic constitutive model, the Anand model, in which plasticity and creep are unified and described by the same set of flow and evolutionary relations, was applied to represent the inelastic deformation behavior for solder alloys. After conducting creep tests and constant strain rate tests, the material parameters for the Anand model of the Pb‐rich content solder 92.5Pb5Sn2.5Ag were determined from the experimental data using a nonlinear fitting method. The material parameters for 60Sn40Pb, 62Sn36Pb2Ag and 96.5Sn3.5Ag solders were fitted from the conventional model in the literature where plasticity and creep are artificially separated. Model simulations and verifications reveal that there is good agreement between the model predictions and experimental data. Some discussion on this unified model is also presented. This viscoplastic constitutive model for solder alloys possesses some advantages over the separated model. The achieved Anand model has been applied in finite element simulation of stress/strain responses in solder joints for chip component, thin quad flat pack and flip‐chip assembly. The simulation results are in good agreement with the results in the literature. It is concluded that the Anand model could be recommended as a useful material model for solder alloys and can be used in the finite element simulation of solder joint reliability in electronic packaging and surface mount technology.

Details

Soldering & Surface Mount Technology, vol. 12 no. 2
Type: Research Article
ISSN: 0954-0911

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Book part
Publication date: 3 May 2016

Benjamin A. T. Graham, Noel P. Johnston and Allison F. Kingsley

Political risk is a complex phenomenon. This complexity has incentivized scholars to take a piecemeal approach to understanding it. Nearly all scholarship has targeted a…

Abstract

Political risk is a complex phenomenon. This complexity has incentivized scholars to take a piecemeal approach to understanding it. Nearly all scholarship has targeted a single type of political risk (expropriation) and, within this risk, a single type of firm (MNCs) and a single type of strategic mechanism through which that risk may be mitigated (entry mode). Yet “political risk” is actually a collection of multiple distinct risks that affect the full spectrum of foreign firms, and these firms vary widely in their capabilities for resisting and evading these risks. We offer a unified theoretical model that can simultaneously analyze: the three main types of political risk (war, expropriation, and transfer restrictions); the universe of private foreign investors (direct investors, portfolio equity investors, portfolio debt investors, and commercial banks); heterogeneity in government constraints; and the three most relevant strategic capabilities (information, exit, and resistance). We leverage the variance among foreign investors to identify effective firm strategies to manage political risk. By employing a simultaneous and unified model of political risk, we also find counterintuitive insights on the way governments trade off between risks and how investors use other investors as risk shields.

Details

Strategy Beyond Markets
Type: Book
ISBN: 978-1-78635-019-0

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Article
Publication date: 4 June 2021

Sanjai Kumar Shukla and Sushil

Organizational capabilities are crucial to achieve the objectives. A plethora of maturity models is available to guide organizational capabilities that create a perplexing…

Abstract

Purpose

Organizational capabilities are crucial to achieve the objectives. A plethora of maturity models is available to guide organizational capabilities that create a perplexing situation about what stuff to improve and what to leave. Therefore, a unified maturity model addressing a wide range of capabilities is a necessity. This paper establishes that a flexibility maturity model is an unified model containing the operational, strategic and human capabilities.

Design/methodology/approach

This paper does a comparative analysis/benchmarking studies of different maturity models/frameworks widely used in the information technology (IT) sector with respect to the flexibility maturity model to establish its comprehensiveness and application in the organization to handle multiple goals.

Findings

This study confirms that the flexibility maturity model has the crucial elements of all the maturity models. If the organizations use the flexibility maturity model, they can avoid the burden of complying with multiple ones and become objective-driven rather than compliance-driven.

Research limitations/implications

The maturity models used in information technology sectors are used. This work will inspire other maturity models to adopt flexibility phenomena.

Practical implications

The comparative analysis will give confidence in application of flexibility framework. The business environment and strategic options across organizations are inherently different that the flexibility maturity model well handles.

Social implications

A choice is put to an organization to see the comparison tables produced in this paper and choose the right framework according to the prevailing business situation.

Originality/value

This is the first study that makes a conclusion based on comparative benchmarking of existing maturity models.

Details

Benchmarking: An International Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1463-5771

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Article
Publication date: 11 February 2014

Anton Joha and Marijn Janssen

Shared services are often viewed as a single type of business model but in reality, shared services can be organized in different ways. The goal of this research is to…

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Abstract

Purpose

Shared services are often viewed as a single type of business model but in reality, shared services can be organized in different ways. The goal of this research is to understand the factors influencing the shaping of shared services business models.

Design/methodology/approach

Inductive case oriented research is conducted by investigating three different types of shared services arrangements using Al-Debei and Avison's unified framework for business models.

Findings

A total of 12 different factors were identified that influence the shape of shared services business models including the path dependency, legal/regulatory driver, customer orientation, target segment, strategic importance, ICT/business orientation, IT governance structure, change strategy, degree of outsourcing, integration potential, economic rationale and the business value.

Research limitations/implications

The level of customization and standardization can influence the potential benefits that can be gained from bundling services and it is important to understand the factors that influence this dimension.

Practical implications

The appropriate configuration of these factors can be helpful to design shared services arrangements with a balanced degree of standardization and customization. The choices regarding the configuration of these factors could result in a more or less effective functioning business model and could influence the governance processes and mechanisms that need to be put in place.

Originality/value

There is no prior research that addresses the shared services business model from a holistic perspective and this research provides a first conceptual model for shared services business models.

Details

Strategic Outsourcing: An International Journal, vol. 7 no. 1
Type: Research Article
ISSN: 1753-8297

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Article
Publication date: 2 August 2011

Xuan Du, Zongbin Li and Song Wang

The purpose of this paper is to realize the integrated optimization of process planning and scheduling in printed circuit board assembly (PCBA).

Abstract

Purpose

The purpose of this paper is to realize the integrated optimization of process planning and scheduling in printed circuit board assembly (PCBA).

Design/methodology/approach

Logical and numerical contour matrix is used to describe the constituent of component and machine for different PCBA processes on the basis of polychromatic sets (PS) theory, and a PS model of PCBA is built. A hybrid genetic algorithm (GA) is developed to optimize the component allocation, PCB assignment and assembly sequence simultaneously.

Findings

Integration of PCBA process planning and scheduling (PCBAPPS) can bridge the gap between design and manufacturing to guarantee the assembly quality and improve the production efficiency. However, PCBAPPS have to search for the optimal result in their own vast solution space. They are complex combinatorial optimization problems. The optimization of PCBAPPS constructs a unified solution space which includes two sub‐solution space stated above. In this paper, dynamic optimization of PCBAPPS is implemented and the solution efficiency is improved.

Originality/value

PS model holds unified standard form on the basis of logical contour and numerical matrix. It is adopted to describe the static structure and dynamic characteristic of PCBA system and combine with GA to solve the integrated optimization problem of PCBAPPS effectively and dynamically.

Details

Assembly Automation, vol. 31 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

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