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1 – 10 of 16Zhengping Li, K Arun and Yan Guan Lim
One of the typical issues in supply chain management (SCM) implementation is how to capture the complexities of supply chains. This paper reviews the existing supply chain…
Abstract
One of the typical issues in supply chain management (SCM) implementation is how to capture the complexities of supply chains. This paper reviews the existing supply chain modelling methods, and identifies the limitations of current methods. Based on these, a novel co‐ordinated supply chain modelling approach is proposed to capture the complexity of supply chains from the views of scenario, interdependency, process and information. The proposed method is comprehensive, inclusive and aims to capture the complexities of a supply chain, align supply chain processes, and provide the basis for supply chain integration.
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Shuanggao Li, Zhengping Deng, Qi Zeng and Xiang Huang
The assembly of large component in out-field is an important part for the usage and maintenance of aircrafts, which is mostly manually accomplished at present, as the commonly…
Abstract
Purpose
The assembly of large component in out-field is an important part for the usage and maintenance of aircrafts, which is mostly manually accomplished at present, as the commonly used large-volume measurement systems are usually inapplicable. This paper aims to propose a novel coaxial alignment method for large aircraft component assembly using distributed monocular vision.
Design/methodology/approach
For each of the mating holes on the components, a monocular vision module is applied to measure the poses of holes, which together shape a distributed monocular vision system. A new unconstrained hole pose optimization model is developed considering the complicated wearing on hole edges, and it is solved by a iterative reweighted particle swarm optimization (IR-PSO) method. Based on the obtained poses of holes, a Plücker line coordinates-based method is proposed for the relative posture evaluation between the components, and the analytical solution of posture parameters is derived. The required movements for coaxial alignment are finally calculated using the kinematics model of parallel mechanism.
Findings
The IR-PSO method derived more accurate hole pose arguments than the state-of-the-art method under complicated wearing situation of holes, and is much more efficient due to the elimination of constraints. The accuracy of the Plücker line coordinates-based relative posture evaluation (PRPE) method is competitive with the singular value decomposition (SVD) method, but it does not rely on the corresponding of point set; thus, it is more appropriate for coaxial alignment.
Practical implications
An automatic coaxial alignment system (ACAS) has been developed for the assembly of a large pilotless aircraft, and a coaxial error of 0.04 mm is realized.
Originality/value
The IR-PSO method can be applied for pose optimization of other cylindrical object, and the analytical solution of Plücker line coordinates-based axes registration is derived for the first time.
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Yifan Jiang, Xiang Huang, Shuanggao Li and Zhengping Deng
The purpose of this paper is to propose an assembly coordination modelling approach based on measured data for assembly quality control of multi-constrained objects in aircraft…
Abstract
Purpose
The purpose of this paper is to propose an assembly coordination modelling approach based on measured data for assembly quality control of multi-constrained objects in aircraft assembly. This approach aims to establish a high-precision digital mirror of physical assembly system in the virtual environment, with which the assembly process in the virtual environment can be performed synchronously with that in the physical world.
Design/methodology/approach
This paper presents a realistic geometrical representation model based on measured point cloud, as well as the multiple constraints modelling methods for local and global constraints with the proposed representation model. For the assembly target optimization, a novel optimization method based on the evaluation of multi-dimensional tolerance zone is proposed, where the particle swarm optimization and simulated annealing algorithm are combined to calculate the optimal solutions.
Findings
As shown in the validation results, the minimum easiness value for easiness model in global optimization is 3.01, while the best value for weighting model by adjusting weights for more than 10 times is 1.94. The results verify that the proposed coordination modelling approach is effective to the assembly of multi-constrained objects, and the optimization model has an obvious advantage over the traditional weighting method.
Originality/value
This paper provides a new idea for the fine control of assembly quality of non-ideal components by introducing the measured data into the on-line assembly process. Besides, a novel optimization method based on the evaluation of multi-dimensional tolerance zone is proposed, which overcomes the problem of traditional weighting model wherein the weightings are difficult to determine.
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Zhengping Deng, Shuanggao Li and Xiang Huang
In aircraft assembly, standard reference points with nominal coordinates are commonly applied for coordinate transformation between multiple measurement stations and the assembly…
Abstract
Purpose
In aircraft assembly, standard reference points with nominal coordinates are commonly applied for coordinate transformation between multiple measurement stations and the assembly coordinate system. For several reasons in practical application, these points often fail to envelop the key assembly space, which leads to large transformation uncertainty. This paper aims to analyze and further reduce the coordinate transformation uncertainty by introducing a new hybrid reference system (HRS).
Design/methodology/approach
Several temporary extension points without known coordinates are added to enhance the tightness between different stations, especially at the weakness area in the network, thus constituting an HRS together with the existing standard reference points. The coordinate transformation model of the HRS-based measurement network is established based on an extend Gauss–Markov model. By using the geometrical differential property and variance-covariance propagation law, the covariance matrixes in the transformation model are calculated, and the analytical solution of the uncertainties of transformation parameters are ultimately derived. The transformation uncertainty of each check points is presented by Helmert error expression.
Findings
The proposed analytical solution of transformation uncertainty is verified using the state-of-the-art Monte Carlo simulation method, but the solution process is simpler and the computation expenses are much less.
Practical implications
The HRS with three temporary extension points is practically applied to a tail boom in-site measurement for assembly. The average transformation uncertainty has been reduced by 26 per cent to less than 0.05 mm.
Originality/value
The hybrid coordinate transformation model is proposed for the first time. The HRS method for transformation uncertainty reduction is more economical and practical than increasing the number of standard reference points.
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Zhengping Deng, Shuanggao Li and Xiang Huang
For the measurement of large-scale components in aircraft assembly, the evaluation of coordinate transformation parameters between the coordinate frames of individual measurement…
Abstract
Purpose
For the measurement of large-scale components in aircraft assembly, the evaluation of coordinate transformation parameters between the coordinate frames of individual measurement systems to the assembly frame is an essential task, which is usually completed by registration of the enhanced reference system (ERS) points. This paper aims to propose an analytical method to evaluate the uncertainties of transformation parameters considering both the measurement error and the deployment error of ERS points.
Design/methodology/approach
For each measuring station, the measured coordinates of ERS points are first roughly registered to the assembly coordinate system using the singular value decomposition method. Then, a linear transformation model considering the measurement error and deployment error of ERS points is developed, and the analytical solution of transformation parameters’ uncertainties is derived. Moreover, the covariance matrix of each ERS points in the transformation evaluation is calculated based on a new uncertainty ellipsoid model and variance-covariance propagation law.
Findings
For the transformation of both single and multiple measuring stations, the derived uncertainties of transformation parameters by the proposed analytical method are identical to that obtained by the state-of-the-art iterative method, but the solution process is simpler, and the computation expenses are much less.
Originality/value
The proposed uncertainty evaluation method would be useful for in-site measurement and optimization of the configuration of ERS points in the design of fixture and large assembly field. It could also be applied to other registration applications with errors on both sides of registration points.
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Zhengping Chang, Zhongqi Wang, Bo Jiang, Jinming Zhang, Feiyan Guo and Yonggang Kang
Riveting deformation is inevitable because of local relatively large material flows and typical compliant parts assembly, which affect the final product dimensional quality and…
Abstract
Purpose
Riveting deformation is inevitable because of local relatively large material flows and typical compliant parts assembly, which affect the final product dimensional quality and fatigue durability. However, traditional approaches are concentrated on elastic assembly variation simulation and do not consider the impact of local plastic deformation. This paper aims to present a successive calculation model to study the riveting deformation where local deformation is taken into consideration.
Design/methodology/approach
Based on the material constitutive model and friction coefficient obtained by experiments, an accurate three-dimensional finite element model was built primarily using ABAQUS and was verified by experiments. A successive calculation model of predicting riveting deformation was implemented by the Python and Matlab and was solved by the ABAQUS. Finally, three configuration experiments were conducted to evaluate the effectiveness of the model.
Findings
The model predicting results, obtained from two simple coupons and a wing panel, showed that it was a good compliant with the experimental results, and the riveting sequences had a significant effect on the distribution and magnitude of deformation.
Practical implications
The proposed model of predicting the deformation from riveting process was available in the early design stages, and some efficient suggestions for controlling deformation could be obtained.
Originality/value
A new predicting model of thin-walled sheet metal parts riveting deformation was presented to help the engineers to predict and control the assembly deformation more exactly.
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Urban planning is the blueprint for the development of urban construction and the basis for management of a city. The urban planning of China’s high-speed modernization has…
Abstract
Urban planning is the blueprint for the development of urban construction and the basis for management of a city. The urban planning of China’s high-speed modernization has encountered many bottlenecks, and the gap between the daily living needs of residents and the urban planning objectives has attracted particular attention. Harmonious development between man and nature is necessary to build a harmonious society, and urban planning that is close to the needs of residents and more humanized has become the main goal of urbanization. In this paper, urban planning of Zhuhai City was studied for one year. Zhuhai focuses on building transport hub, industrial layout, and urban development in three major patterns. Many problems in the planning and management of Zhuhai City were encountered in the past, because the plans are only heavy concepts that ignore implementation and lack of comprehensive survey. Based on the concept of communication planning, the main features of the public participation in the urban planning model through modern mass media may be suitable for achieving the objectives and satisfying public needs. Urban planning and decision-making in Zhuhai City in recent years are evaluated by SWOT method. Future plans of Zhuhai City are discussed.
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Shengfu Xue, Zhengping He, Bingzhi Chen and Jianxin Xu
This study investigates the fitting techniques for notch fatigue curves, seeking a more reliable method to predict the lifespan of welded structures.
Abstract
Purpose
This study investigates the fitting techniques for notch fatigue curves, seeking a more reliable method to predict the lifespan of welded structures.
Design/methodology/approach
Building on the fatigue test results of butt and cruciform joints, this research delves into the selection of fitting methods for the notch fatigue curve of welded joints. Both empirical formula and finite element methods (FEMs) were employed to assess the notch stress concentration factor at the toe and root of the two types of welded joints. Considering the mean stress correction and weld misalignment coefficients, the notch fatigue life curves were established using both direct and indirect methods.
Findings
An engineering example was employed to discern the differences between the direct and indirect approaches. The findings highlight the enhanced reliability of the indirect method for fitting the fatigue life curve.
Originality/value
While the notch stress approach is extensively adopted due to its accurate prediction of component fatigue life, most scholars have overlooked the importance of its curve fitting methods. Existing literature scantily addresses the establishment of these curves. This paper offers a focused examination of fatigue curve fitting techniques, delivering valuable perspectives on method selection.
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Ra’ed Masa’deh, Jawaher Al-Henzab, Ali Tarhini and Bader Yousef Obeidat
The purpose of this paper is to explore the relationship between three variables of strategic orientation (market orientation, technology orientation entrepreneurial orientation…
Abstract
Purpose
The purpose of this paper is to explore the relationship between three variables of strategic orientation (market orientation, technology orientation entrepreneurial orientation) and organizational performance in the Jordanian pharmaceutical sector.
Design/methodology/approach
This study employed a quantitative research design where 252 questionnaires were collected form respondents operating in various pharmaceutical companies in Jordan to obtain necessary data to test the hypotheses developed for the study. Multiple regressions were used to analyze the research data.
Findings
The results of the analysis revealed that strategic orientations were positively and significantly related to organizational performance. The findings also showed that market orientation contributed the most to the enhancement of organizational development followed by technology orientation and finally entrepreneurship orientation.
Practical implications
These findings contribute to the understanding of the importance of employing multiple strategic orientations in order to enhance organizational performance, particularly in pharmaceutical companies
Originality/value
This is the first study which adequately covers the relationship between three variables of strategic orientation (market orientation, technology orientation, entrepreneurial orientation) and organizational performance in the Jordanian pharmaceutical sector.
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Syed Asif Raza and Mohd. Nishat Faisal
This paper aims to develop efficient decision support tools for a firm’s environment protection by using greening effort while yet improving profitability by utilizing pricing and…
Abstract
Purpose
This paper aims to develop efficient decision support tools for a firm’s environment protection by using greening effort while yet improving profitability by utilizing pricing and inventory decisions with discount consideration.
Design/methodology/approach
This study proposed a mathematical model for price- and greening effort-dependent demand rate with discount considerations. Later, the mathematical model is extended to the situation in which the demand rate is also dependent on the stock level, in addition to the price and greening effort. Efficient solution methodologies are developed for finding the optimal solution to the proposed models.
Findings
Simple yet elegant models are proposed to mimic real-life applications. Structural properties of the models are explored to outline efficient algorithms with quantity discounts.
Research limitations/implications
The paper considers monopoly and assumes deterministic demand. Only a more commonly observed all-units discount scheme is studied.
Practical implications
The models provide decision support tools for firms in pursuit of joint profit maximization and environment consciousness goals.
Social implications
The study develops environment-friendly approaches for inventory management and improving the profitability alike.
Originality/value
This study is among the first to consider environmental protection with an investment in greening effort along with inventory management and pricing decision. The study also explored the effect of all-unit quantity discounts.
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