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1 – 10 of over 52000Arijit Maji and Indrajit Mukherjee
The purpose of this study is to propose an effective unsupervised one-class-classifier (OCC) support vector machine (SVM)-based single multivariate control chart (OCC-SVM) to…
Abstract
Purpose
The purpose of this study is to propose an effective unsupervised one-class-classifier (OCC) support vector machine (SVM)-based single multivariate control chart (OCC-SVM) to simultaneously monitor “location” and “scale” shifts of a manufacturing process.
Design/methodology/approach
The step-by-step approach to developing, implementing and fine-tuning the intrinsic parameters of the OCC-SVM chart is demonstrated based on simulation and two real-life case examples.
Findings
A comparative study, considering varied known and unknown response distributions, indicates that the OCC-SVM is highly effective in detecting process shifts of samples with individual observations. OCC-SVM chart also shows promising results for samples with a rational subgroup of observations. In addition, the results also indicate that the performance of OCC-SVM is unaffected by the small reference sample size.
Research limitations/implications
The sample responses are considered identically distributed with no significant multivariate autocorrelation between sample observations.
Practical implications
The proposed easy-to-implement chart shows satisfactory performance to detect an out-of-control signal with known or unknown response distributions.
Originality/value
Various multivariate (e.g. parametric or nonparametric) control chart(s) are recommended to monitor the mean (e.g. location) and variance (e.g. scale) of multiple correlated responses in a manufacturing process. However, real-life implementation of a parametric control chart may be complex due to its restrictive response distribution assumptions. There is no evidence of work in the open literature that demonstrates the suitability of an unsupervised OCC-SVM chart to simultaneously monitor “location” and “scale” shifts of multivariate responses. Thus, a new efficient OCC-SVM single chart approach is proposed to address this gap to monitor a multivariate manufacturing process with unknown response distributions.
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Ala Al‐Fuqaha, Mohammed Elbes and Ammar Rayes
Outdoor localization is an important issue for many applications, such as autonomous mobile robotics and augmented reality. The purpose of this paper is to propose a budgeted…
Abstract
Purpose
Outdoor localization is an important issue for many applications, such as autonomous mobile robotics and augmented reality. The purpose of this paper is to propose a budgeted dynamic exclusion heuristic based on signal phase shifts from multiple base stations.
Design/methodology/approach
The authors also propose an outdoor localization technique based on the particle filter for data fusion and present an overview of a potential target application of the proposed outdoor localization approach for the blind and visually impaired (BVI).
Findings
The combination of multiple sensor data tends to overcome the drawbacks of using one sensor technology in the localization process.
Originality/value
The novelty of the proposed approach stems from its ability to fuse data collected from different sensor technologies to converge to more accurate position estimation.
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Asad Ali Qazi, Abdul Rehman Shaikh, Farhan Shahzad and Muhammad Muzamil Sattar
The learning outcomes are as follows: to understand the strategic importance of location selection within the organization and how it influences other’s performance; to understand…
Abstract
Learning outcomes
The learning outcomes are as follows: to understand the strategic importance of location selection within the organization and how it influences other’s performance; to understand the impact of supply chain drivers on sales performance and to understand the role of other stakeholders in location selection strategy; to analyze the constraints in decision-making for selection of warehouse location and its remedies; to analyze the alternative options for warehouse in the light of top level management’s instruction or organizational strategies; to select the best possible alternate for long-term sustainability of warehouse location.
Case overview/synopsis
Ishaq Bashir, who has recently joined Super Distribution Services as Facility Manager, is indecisive in selecting a rental location for its offices and warehouse, either SDS had to move back to the old location or continue with existing warehouse facility. This existing location was selected by Ex Facility Manager around six months ago because SDS had to vacate their old location due to graving concern the owner of the premises. SDS had to search for a new facility and vacate the older premises within three months’ time as per “evacuation notice” received from the owner, and finally, the company shifted to the new location by 28 February 2017. After six months in September 2017, sales team realized a serious dip in sales by 1 per cent, and they claimed that this had happened due to wrong selection of the location of the warehouse which was far from the city. Now Bashir had to decide either to continue with the existing facility or move to the previous one or search for any third feasible location.
Complexity academic level
BBA and MBA.
Supplementary materials
Teaching Notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.
Subject code
CSS 9: Operations and Logistics.
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Steven J. Cochran and Iqbal Mansur
This study examines the durations of US stock market cycle expansions and contractions for the presence of seasonality. Specifically, it is determined whether the distributional…
Abstract
This study examines the durations of US stock market cycle expansions and contractions for the presence of seasonality. Specifically, it is determined whether the distributional characteristics (i.e., location and dispersion) of the durations of market expansions and contractions are dependent on the time of the year the market phase begins or ends. The duration data are obtained from a stock market chronology of monthly peak and trough dates for the period May 1835 through July 1998 and nonparametric rank‐based tests are used to test for the presence of seasonality. In order to provide some evidence on robustness with respect to the sample data, results are obtained for the entire sample period as well as for various sub‐periods. When the data are aggregated on a quarterly basis, the evidence suggests that seasonal structures are present in stock market cycle durations. These seasonals are related primarily to shifts in location over the course of the year and to when a market expansion or contraction begins. However, when the duration data are aggregated on a bi‐annual basis, support for seasonality is much more limited.
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Retailing in Scotland has shown dynamism in the last decade.Assesses the factors which have influenced change and how Scotlanddiffers from the rest of the UK in terms of market…
Abstract
Retailing in Scotland has shown dynamism in the last decade. Assesses the factors which have influenced change and how Scotland differs from the rest of the UK in terms of market concentration, corporate decision making and inter‐format competition.
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Catherine Cassell and Bill Lee
The aim of this paper is to provide a piece of empirical work that examines the impact of trade union learning representatives in enabling access to learning by those groups…
Abstract
Purpose
The aim of this paper is to provide a piece of empirical work that examines the impact of trade union learning representatives in enabling access to learning by those groups traditionally less likely to access such opportunities. This aim is discussed in relation to the literature on the significance of organizational learning.
Design/methodology/approach
The research conducted included an in‐depth qualitative interview study of full‐time trade union officials with some responsibility for learning in their union.
Findings
The findings are discussed in relation to how trade union learning representatives are approaching their role; how learning is being facilitated; who is gaining access to learning and how; and the ownership of learning more generally.
Originality/value
The paper presents original data on a new learning initiative about which very little is currently published.
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Jeffrey T. Macher and David C. Mowery
We examine the evolution of vertical specialization in three industries: chemicals, computers, and semiconductors. Vertical specialization is the restructuring of industry-wide…
Abstract
We examine the evolution of vertical specialization in three industries: chemicals, computers, and semiconductors. Vertical specialization is the restructuring of industry-wide value chains, such that different stages are controlled by different firms, rather than being vertically integrated within the boundaries of individual firms. In some cases, vertical specialization may span international boundaries and is associated with complex international production networks. After decades of vertical specialization, firms in the chemical industry are re-integrating stages of the value chain. By contrast, the semiconductor and computer industries have experienced significant vertical specialization during the past ten years. We examine how and why these contrasting trends in vertical specialization have co-evolved with industry maturation and decline, and underscore the importance and role of both industry factors and business strategies necessary for industries to become more specialized. We also consider the effects of vertical specialization on the sources of innovation and the geographic redistribution of production and other activities. We conclude that the evolution of vertical specialization in these three industries has both reflected and influenced the strategies of leading firms, while also displays industry-specific characteristics that are rooted in different technological and market characteristics.
Dezhi Chen, William Wei, Daiping Hu and Etayankara Muralidharan
Although there have been many discussions on the status and development of original equipment manufacturers (OEMs), theory on how they survive is minimal. Little is known about…
Abstract
Purpose
Although there have been many discussions on the status and development of original equipment manufacturers (OEMs), theory on how they survive is minimal. Little is known about how OEMs survive and upgrade to other business models, such as original design manufacturers (ODMs) and original brand manufacturers (OBMs), in emerging economies. The purpose of this paper is to extend the theory on the survival path of OEMs from the perspective of emerging countries by examining how OEMs survive cost pressures and upgrade to ODMs or OBMs.
Design/methodology/approach
Using a multi-case study method, this study analyzes the survival path employed by OEMs by examining eight firms in the Chinese toy industry.
Findings
This study shows that OEMs remain weak in the global toy industry chain due to labor costs. While some OEMs move to low-cost regions, others turn to OBM management, after transitioning through an ODM model, by investing in research and development and marketing.
Originality/value
This study explores the survival paths of OEM enterprises, showing that OEMs can first upgrade to ODMs and then to OBMs, or they can directly upgrade to OBMs. Shifting from OEM to ODM is an important step in the transition process, although the contract that OEMs have with their foreign partners does not change significantly.
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Pham Duc Tai, Krit Jinawat and Jirachai Buddhakulsomsiri
Distribution network design involves a set of strategic decisions in supply chains because of their long-term impacts on the total logistics cost and environment. To incorporate a…
Abstract
Purpose
Distribution network design involves a set of strategic decisions in supply chains because of their long-term impacts on the total logistics cost and environment. To incorporate a trade-off between financial and environmental aspects of these decisions, this paper aims to determine an optimal location, among candidate locations, of a new logistics center, its capacity, as well as optimal network flows for an existing distribution network, while concurrently minimizing the total logistics cost and gas emission. In addition, uncertainty in transportation and warehousing costs are considered.
Design/methodology/approach
The problem is formulated as a fuzzy multiobjective mathematical model. The effectiveness of this model is demonstrated using an industrial case study. The problem instance is a four-echelon distribution network with 22 products and a planning horizon of 20 periods. The model is solved by using the min–max and augmented ε-constraint methods with CPLEX as the solver. In addition to illustrating model’s applicability, the effect of choosing a new warehouse in the model is investigated through a scenario analysis.
Findings
For the applicability of the model, the results indicate that the augmented ε-constraint approach provides a set of Pareto solutions, which represents the ideal trade-off between the total logistics cost and gas emission. Through a case study problem instance, the augmented ε-constraint approach is recommended for similar network design problems. From a scenario analysis, when the operational cost of the new warehouse is within a specific fraction of the warehousing cost of third-party warehouses, the solution with the new warehouse outperforms that without the new warehouse with respective to financial and environmental objectives.
Originality/value
The proposed model is an effective decision support tool for management, who would like to assess the impact of network planning decisions on the performance of their supply chains with respect to both financial and environmental aspects under uncertainty.
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Yinglong Chen, Wenshuo Li and Yongjun Gong
The purpose of this paper is to estimate the deformation of soft manipulators caused by obstacles accurately and the contact force and workspace can be also predicted.
Abstract
Purpose
The purpose of this paper is to estimate the deformation of soft manipulators caused by obstacles accurately and the contact force and workspace can be also predicted.
Design/methodology/approach
The continuum deformation of the backbone of the soft manipulator under contact is regarded as two constant curvature arcs and the curvatures are different according to the fluid pressure and obstacle location based on piecewise constant curvature framework. Then, this study introduces introduce the moment balance and energy conservation equation to describe the static relationship between driving moment, elastic moment and contact moment. Finally, simulation and experiments are carried out to verify the accuracy of the proposed model.
Findings
For rigid manipulators, environmental contact except for the manipulated object was usually considered as a “collision” which should be avoided. For soft manipulators, an environment is an important tool for achieving manipulation goals and it might even be considered to be a part of the soft manipulator’s end-effector in some specified situations.
Research limitations/implications
There are also some limitations to the presented study. Although this paper has made progress in the static modeling under environmental contact, some practical factors still limit the further application of the model, such as the detection accuracy of the environment location and the deformation of the contact surface.
Originality/value
Based on the proposed kinematic model, the bending deformation with environmental contact is discussed in simulations and has been experimentally verified. The comparison results show the correctness and accuracy of the presented SCC model, which can be applied to predict the slender deformation under environmental contact without knowing the contact force.
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