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Article
Publication date: 20 April 2022

Binghai Zhou, Qi Yi, Xiujuan Li and Yutong Zhu

This paper aims to investigate a multi-objective electric vehicle’s (EV’s) synergetic scheduling problem in the automotive industry, where a synergetic delivery mechanism to…

141

Abstract

Purpose

This paper aims to investigate a multi-objective electric vehicle’s (EV’s) synergetic scheduling problem in the automotive industry, where a synergetic delivery mechanism to coordinate multiple EVs is proposed to fulfill part feeding tasks.

Design/methodology/approach

A chaotic reference-guided multi-objective evolutionary algorithm based on self-adaptive local search (CRMSL) is constructed to deal with the problem. The proposed CRMSL benefits from the combination of reference vectors guided evolutionary algorithm (RVEA) and chaotic search. A novel directional rank sorting procedure and a self-adaptive energy-efficient local search strategy are then incorporated into the framework of the CRMSL to obtain satisfactory computational performance.

Findings

The involvement of the chaotic search and self-adaptive energy-efficient local search strategy contributes to obtaining a stronger global and local search capability. The computational results demonstrate that the CRMSL achieves better performance than the other two well-known benchmark algorithms in terms of four performance metrics, which is inspiring for future researches on energy-efficient co-scheduling topics in manufacturing industries.

Originality/value

This research fully considers the cooperation and coordination of handling devices to reduce energy consumption, and an improved multi-objective evolutionary algorithm is creatively applied to solve the proposed engineering problem.

Details

Engineering Computations, vol. 39 no. 7
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 31 July 2007

Min Tang, J.F. Mao and L.L. Jiang

This paper aims to obtain the optimal wire sizing of buffered global interconnects and to investigate the impact of weight factor on the optimized system performance for various…

238

Abstract

Purpose

This paper aims to obtain the optimal wire sizing of buffered global interconnects and to investigate the impact of weight factor on the optimized system performance for various technology nodes.

Design/methodology/approach

The width and spacing of interconnects are optimized under two scenarios, and corresponding optimum line width is determined by minimizing the value of power‐delay product which is defined as a figure of merit (FOM). Based on the results, the impact of weight factor on the optimized system performance, such as delay and power dissipation per unit length, is analyzed for various technology nodes.

Findings

The analytical expressions of the optimum width are derived under two scenarios. Better FOMs can be achieved for the S=W scenario, but the wireability of the chip degrades considerably. The optimized delay increases with the increasing of weight factor, while the optimized power dissipation decreases with it. For a given weight factor, smaller latency and less power dissipation can be achieved for the S=W case.

Originality/value

The analytical expressions of the optimum width of interconnects are given, and a comprehensive study of the impact of weight factor on the optimized results under two scenarios is presented.

Details

Microelectronics International, vol. 24 no. 3
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 19 October 2022

Fatimah A.M. Al-Zahrani

This paper aims to prepare a new donor–π–acceptor (D–π–A) and acceptor–π– D–π–A (A–π–D–π–A) phenothiazine (PTZ) in conjugation with vinyl isophorone (PTZ-1 and PTZ-2) were…

148

Abstract

Purpose

This paper aims to prepare a new donor–π–acceptor (D–π–A) and acceptor–π– D–π–A (A–π–D–π–A) phenothiazine (PTZ) in conjugation with vinyl isophorone (PTZ-1 and PTZ-2) were designed and their molecular shape, electrical structures and characteristics have been explored using the density functional theory (DFT). The results satisfactorily explain that the higher conjugative effect resulted in a smaller high occupied molecular orbital–lowest unoccupied molecular orbital gap (Eg). Both compounds show intramolecular charge transfer (ICT) transitions in the ultraviolet (UV)–visible range, with a bathochromic shift and higher absorption oscillator strength, as determined by DFT calculations.

Design/methodology/approach

The produced PTZ-1 and PTZ-2 sensors were characterized using various spectroscopic methods, including Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy (1H/13CNMR). UV–visible absorbance spectra of the generated D–π–A PTZ-1 and A–π–D–π–A PTZ-2 dyes were explored in different solvents of changeable polarities to illustrate positive solvatochromism correlated to intramolecular charge transfer.

Findings

The emission spectra of PTZ-1 and PTZ-2 showed strong solvent-dependent band intensity and wavelength. Stokes shifts were monitored to increase with the increase of the solvent polarity up to 4122 cm−1 for the most polar solvent. Linear energy-solvation relationship was applied to inspect solvent-dependent Stokes shifting. Quantum yield (ф) of PTZ-1 and PTZ-2 was also explored. The maximum UV–visible absorbance wavelengths were detected at 417 and 419 nm, whereas the fluorescence intensity was monitored at 586 and 588 nm.

Originality/value

The PTZ-1 and PTZ-2 dyes leading to colorimetric and emission spectral changes together with a color shift from yellow to red.

Details

Pigment & Resin Technology, vol. 53 no. 3
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 13 December 2017

Cengiz Deniz and Mustafa Cakir

This paper aims to introduce a simple hand-eye calibration method that can be easily applied with different objective functions.

370

Abstract

Purpose

This paper aims to introduce a simple hand-eye calibration method that can be easily applied with different objective functions.

Design/methodology/approach

The hand-eye calibration is solved by using the closed form absolute orientation equations. Instead of processing all samples together, the proposed method goes through all minimal solution sets. Final result is chosen after evaluating the solution set for arbitrary objectives. In this stage, outliers can be excluded optionally if more accuracy is desired.

Findings

The proposed method is very flexible and gives more accurate and convenient results than the existing solutions. The mathematical error expression defined by the calibration equations may not be valid in practice, where especially systematic distortions are present. It is shown in the simulations that the solution which results the least mathematical error in systems may have incorrect, incompatible results in the presence of practical demands.

Research limitations/implications

The performance of the calibration performed with the proposed method is compared with the reference methods in the literature. When the back-projection error is benchmarked, which corresponds to the point repeatability, the proposed approach is considered as the most successful method among all others. Due to its robustness, it is decided to make tooling-sensor calibrations by the recommended method, in the robotic non-destructive testing station in Ford-OTOSAN Kocaeli Plant Body Shop Department.

Originality/value

Arranging the well-known AX = XB calibration equation in quaternion representation as Q_A = Q_x × Q_B × Q_x reveals another common spatial rotation equation. In this way, absolute orientation solution satisfies the hand-eye calibration equations. The proposed solution is not presented in the literature as a standalone hand-eye calibration method, although some researchers drop a hint to the relative formulations.

Details

Industrial Robot: An International Journal, vol. 45 no. 1
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 10 January 2025

Virajan Verma, Khair Ul Faisal Wani and Sahil Dhiman

The issue of evaluating the dynamic characteristics of a bridge due to the presence of rapidly moving vehicles has considerable importance. This study aims to conduct a…

7

Abstract

Purpose

The issue of evaluating the dynamic characteristics of a bridge due to the presence of rapidly moving vehicles has considerable importance. This study aims to conduct a comprehensive study on the variables that influence the dynamic behavior of a thin-walled box-girder bridge exposed to high-speed train loads using regression analysis.

Design/methodology/approach

The high-speed train is mathematically represented by a system with 38 degrees of freedom (DOF), while the sub-track system uses China’s Railway Track System slab track. The numerical modeling of the bridge is accomplished using computationally efficient finite elements that represent thin-walled box-beams. The rail’s imperfections are also accounted for, and they are represented using a power spectral density function. The dynamic response of the bridge is calculated using the Newmark-beta technique, considering several DOFs and stress resultants.

Findings

A thorough parametric analysis of the factors affecting the dynamic response of the bridge is conducted and a regression model has been proposed. The regression equation yields an excellent fit for shear force, distortional moment and distortional bimoment, with an R2 value near 1. It has also been observed that the range of the coefficient R2 in case of bending moment, torsion, torsional bimoment and vertical deflection typically falls between 0.82 and 0.9. R2 value near to 1 indicates that it is quite accurate in forecasting the dynamic influence of high-speed trains on the bridge’s response.

Originality/value

The originality of this research lies in pioneering the regression modeling of dynamic responses in thin-walled box-girder bridges and uniquely modeling high-speed trains with 38 DOF, which has not been previously explored in existing studies.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 6 November 2017

Jiawei Wang, Feng Chen, Jinghui Shao, Weichen Zhang and Xikui Ma

This paper aims to present a novel hybrid time integration approach for efficient numerical simulations of multiscale problems involving interactions of electromagnetic fields…

249

Abstract

Purpose

This paper aims to present a novel hybrid time integration approach for efficient numerical simulations of multiscale problems involving interactions of electromagnetic fields with fine structures.

Design/methodology/approach

The entire computational domain is discretized with a coarse grid and a locally refined subgrid containing the tiny objects. On the coarse grid, the time integration of Maxwell’s equations is realized by the conventional finite-difference technique, while on the subgrid, the unconditionally stable Krylov-subspace-exponential method is adopted to breakthrough the Courant–Friedrichs–Lewy stability condition.

Findings

It is shown that in contrast with the conventional finite-difference time-domain method, the proposed approach significantly reduces the memory costs and computation time while providing comparative results.

Originality/value

An efficient hybrid time integration approach for numerical simulations of multiscale electromagnetic problems is presented.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 6
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 June 2022

Jun Wu, Hong-Zhong Huang, Yan-Feng Li, Song Bai and Ao-Di Yu

Aero-engine components endure combined high and low cycle fatigue (CCF) loading during service, which has attracted more research attention in recent years. This study aims to…

295

Abstract

Purpose

Aero-engine components endure combined high and low cycle fatigue (CCF) loading during service, which has attracted more research attention in recent years. This study aims to construct a new framework for the prediction of probabilistic fatigue life and reliability evaluation of an aero-engine turbine shaft under CCF loading if considering the material uncertainty.

Design/methodology/approach

To study the CCF failure of the aero-engine turbine shaft, a CCF test is carried out. An improved damage accumulation model is first introduced to predict the CCF life and present high prediction accuracy in the CCF loading situation based on the test. Then, the probabilistic fatigue life of the turbine shaft is predicted based on the finite element analysis and Monte Carlo analysis, where the material uncertainty is taken into account. At last, the reliability evaluation of the turbine shaft is conducted by stress-strength interference models based on an improved damage accumulation model.

Findings

The results indicate that predictions agree well with the tested data. The improved damage accumulation model can accurately predict the CCF life because of interaction damage between low cycle fatigue loading and high cycle fatigue loading. As a result, a framework is available for accurate probabilistic fatigue life prediction and reliability evaluation.

Practical implications

The proposed framework and the presented testing in this study show high efficiency on probabilistic CCF fatigue life prediction and can provide technical support for fatigue optimization of the turbine shaft.

Originality/value

The novelty of this work is that CCF loading and material uncertainty are considered in probabilistic fatigue life prediction.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 10
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 4 May 2012

Mirjana S. Damnjanović, Ljiljana D. Živanov, Snezana M. Djurić, Andrea M. Marić, Aleksandar B. Menićanin, Goran J. Radosavljević and Nelu V. Blaž

Significant achievements in ferrite material processing enable developments of many ferrite devices with a wide range of power levels and working frequencies, which make demands…

438

Abstract

Purpose

Significant achievements in ferrite material processing enable developments of many ferrite devices with a wide range of power levels and working frequencies, which make demands for new characterization and modelling methods for ferrite materials and components. The purpose of this paper is to introduce a modelling and measurement procedure, which can be used for the characterization of two‐port ferrite components in high frequency range.

Design/methodology/approach

This paper presents a commercially available ferrite component (transformer) modelling and determination of its electrical parameters using in‐house developed software. The components are measured and characterized using a vector network analyzer E5071B and adaptation test fixture on PCB board. The parameters of electrical equivalent circuit of the ferrite transformer parameters are compared with values extracted out of measured scattering parameters.

Findings

A good agreement between modelled and extracted electrical parameters of the ferrite transformer is found. The modelled inductance curves have the same dependence versus frequency as extracted ones. That confirms the model validity in the wide frequency range.

Originality/value

In‐house developed software based on proposed model provides inclusion of the ferrite material dispersive characteristics, which dominantly determines high‐frequency behaviour of two‐port ferrite components. Developed software enables fast and accurate calculation of the ferrite transformer electrical parameters and its redesign in order to achieve the best performance for required application.

Details

Microelectronics International, vol. 29 no. 2
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 30 August 2013

Lijia Wang, Xuexi Huo and Shajahan Kabir

At the center of apple production province in China, how to increase apple per unit yield and to improve apple production efficiency in Shaanxi become big issues. The objectives…

1067

Abstract

Purpose

At the center of apple production province in China, how to increase apple per unit yield and to improve apple production efficiency in Shaanxi become big issues. The objectives of this paper are to investigate the technical efficiency (TE) and cost efficiency (CE) of apple orchard and to analyse determinants which affect apple production efficiency. The paper aims to discuss these issues.

Design/methodology/approach

This paper conducts a two‐stage DEA to achieve the objectives. In the first‐stage, a cost minimization model is applied to measure apple production efficiency. Then, a Tobit model is provided to estimate regression coefficients which are used to adjust the efficiency scores in the first‐stage.

Findings

The results indicate that TE and CE are rather low in Shaanxi. The research also explores that the inefficient production of apple farmers is caused mainly by two aspects. One is the inefficient apple orchards operation of farmers. The other is the disadvantageous environmental conditions which heavily affect apple growth and fruit bearing situation.

Originality/value

Most of the research are based on national statistical data, and only measure the TE. This paper primarily focuses on the estimation of efficiency scores with the data involved in both quantity and price information of traditional inputs and outputs based on 255 apple farmers in Shaanxi. Specifically, This paper also consider farmer's opportunity cost to which little literature refers. The results not only reveal the efficient determinants of apple production, but also provide suggestions for agricultural policy makers.

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Article
Publication date: 22 December 2023

Recai Coşkun and Oğuzhan Öztürk

This study aims to critically evaluate resource dependence theory’s (RDT) assumptions and explanations about dependence and the dependent firm’s strategic options. The authors…

540

Abstract

Purpose

This study aims to critically evaluate resource dependence theory’s (RDT) assumptions and explanations about dependence and the dependent firm’s strategic options. The authors argue that RDT’s perception of dependence is problematic because it evaluates dependence as a purely negative situation in which all firms, by definition, seek to develop strategies to change the power structure of such relationships. On the contrary, the authors argue that there are situations in which dependent firms are in agreement with dependence and, therefore, develop strategies that do not aim to change the balance of power in the relationship, but rather to strengthen their position within the relationship.

Design/methodology/approach

The research is designed as a theoretical discussion. The authors critically evaluate and discuss current understanding and assumptions about RDT’s dependence explanations. Drawing on insights from the strategic management literature, the authors offer a new perspective on the problematic areas in the dependence explanations of the RDT.

Findings

Drawing on insights from the strategic management literature, the authors argue that dependent firms enjoy certain advantages due to the dependence relationship to gain sustainable competitive advantages over their rivals and potential competitors. These advantages include factors such as increasing growth potential, developing capabilities and competencies, building relationships of trust with powerful firms and leveraging their reputations and references that contribute to the sustainable strategic advantages of dependent firms. The authors believe that this study has the potential to spur new research that further challenges the assumptions of the RDT and empirically tests its propositions.

Originality/value

The authors propose a research framework on dependence as a strategic option that has the possibility of expanding RDT’s current dependence explanation.

Details

International Journal of Organizational Analysis, vol. 32 no. 9
Type: Research Article
ISSN: 1934-8835

Keywords

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