Yong Yue, J.L. Murray, J.R. Corney and D.E.R. Clark
The problem of constructing the convex hull of a set of points and of curvilinear segments arises in many applications of geometric analysis. Although there has been much work on…
Abstract
The problem of constructing the convex hull of a set of points and of curvilinear segments arises in many applications of geometric analysis. Although there has been much work on algorithms for the convex hull of a finite point set, there has been less on methods for dealing with circular line segments and the implementation issues. This paper describes a new method for finding the convex hull of a planar set of straight and circular line segments. It then concentrates on the implementation of the algorithm.
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H. Medellín, J. Corney, J.B.C. Davies, T. Lim and J.M. Ritchie
This paper presents a novel approach for rapid prototyping based on the octree decomposition of 3D geometric models. The proposed method, referred as OcBlox, integrates an octree…
Abstract
This paper presents a novel approach for rapid prototyping based on the octree decomposition of 3D geometric models. The proposed method, referred as OcBlox, integrates an octree modeller, an assembly planning system, and a robotic assembly cell into an integrated system that builds approximate prototypes directly from 3D model data. Given an exact 3D model this system generates an octree decomposition of it, which approximates the shape cubic units referred as “Blox”. These cuboid units are automatically assembled to obtain an approximate physical prototype. This paper details the algorithms used to generate the octree's assembly sequence and demonstrates the feasibility of the OcBlox approach by describing a single resolution example of a prototype built with this automated system. An analysis of the potential of the approach to decrease the manufacturing time of physical components is detailed. Finally, the potential of OcBlox to support complex overhanging geometry is discussed.
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This article reports the evaluation of the Choices Project, an initiative which was developed to address health inequalities and was piloted in a medical centre in an area of…
Abstract
This article reports the evaluation of the Choices Project, an initiative which was developed to address health inequalities and was piloted in a medical centre in an area of multiple deprivation. The article reports an evaluation of the pilot. The Project was found to have achieved its aims of addressing the mental, social and emotional health needs of clients living in a deprived area, and facilitating a multi‐agency approach to primary care health promotion. In addition to running a consultation clinic, the Project workers set up advice services, such as a welfare benefits and debt counselling service, and provided information about local resources. The results of the evaluation demonstrated the approach to be valued by the staff of the medical centre and effective for a significant number of clients who presented with a variety of problems which had serious consequences for health, but which were not caused by problems traditionally viewed as medical.
Hugo Medellin, Jonathan Corney, James Ritchie and Theodore Lim
This paper aims to investigate automatic assembly planning for robot and manual assembly.
Abstract
Purpose
This paper aims to investigate automatic assembly planning for robot and manual assembly.
Design/methodology/approach
The octree decomposition technique is applied to approximate a computer‐aided design model with an octree representation which is then used to generate robot and manual assembly plans. An assembly planning system able to generate assembly plans was developed to build these prototype models.
Findings
Octree decomposition is an effective assembly planning tool. Assembly plans can automatically be generated for robot and manual assembly using octree models.
Research limitations/implications
One disadvantage of the octree decomposition technique is that it approximates a part model with cubes instead of using the actual model. This limits its use and applications when complex assemblies must be planned, but in the context of prototyping can allow a rough component to be formed which can later be finished by hand.
Practical implications
Assembly plans can be generated using octree decomposition, however, new algorithms must be developed to overcome its limitations.
Originality/value
This paper has proved that the octree decomposition technique is an effective assembly planning tool. As a result, an assembly planning system has been developed. Assembly plans for automatic and manual assembly can be generated automatically by the proposed system, which is a novelty since there are no fully automatic assembly planning systems for manual assembly reported in the literature.
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Alberto Martinez-Corral, Mercedes Grijalvo and Miguel Palacios
Since Howe (2006) first used the term crowdsourcing to define the outsourcing of activities by companies to individuals through the use of the internet, a growing literature has…
Abstract
Purpose
Since Howe (2006) first used the term crowdsourcing to define the outsourcing of activities by companies to individuals through the use of the internet, a growing literature has developed on the subject. Its emergence as a new paradigm in problem solving and value creation in the digital innovation ecosystem has produced significant publications in the management field, but publications about some aspects of organisations are still missing. Such is the case regarding the impact that these crowdsourcing initiatives have on organisations. This paper advances in that direction by proposing a new approach for the review of these activities through a detailed model of the elements of organisational levels that describe the crowdsourcing processes. The paper aims to discuss these issues.
Design/methodology/approach
Crowdsourcing models in the literature are reviewed to propose the new model, complemented by a survey of scholars and practitioners to validate the approach introduced.
Findings
The results provide a detailed link between the two fields: crowdsourcing models and organisational levels, developed through the connection of the elements of organisational levels and the dimensions of different crowdsourcing models. The identification of the elements that constitute each organisational level, their inclusion in a new model and the order of relevance of the different elements in the crowdsourcing initiatives could have an implication for academics and practitioners involved in implementing crowdsourcing.
Originality/value
The originality of this research is the introduction of a new approach for the analysis of crowdsourcing initiatives, establishing a new framework model to connect crowdsourcing models and organisational levels for new organisations.
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Fernando J. Garrigos‐Simon, Rafael Lapiedra Alcamí and Teresa Barberá Ribera
Innovations, coupled with the advancement of new information and communication technologies (ICTs) and the evolution of the internet, have had a profound impact on the structure…
Abstract
Purpose
Innovations, coupled with the advancement of new information and communication technologies (ICTs) and the evolution of the internet, have had a profound impact on the structure of firms and have altered the decision‐making process. In the new economic and social environment, the understanding of the developments and transformations undergone by ICTs with the advancement of social networks and Web 3.0 technology is vital because of the influence of recent innovations in the competitiveness of organizations. The aim of this paper is to achieve an in‐depth understanding of the new environment that has emerged with these developments.
Design/methodology/approach
The study focuses on the use of social networks and the conception of the corresponding new business models, highlighting the importance of community managers and crowdsourcing processes.
Findings
The paper explores the possible sources of competitive advantages open to organizations in the light of recent innovations, and highlights the developments that they should implement to improve the decision management process and exploit new situations.
Practical implications
The paper analyzes the impact of social networks and Web 3.0 technology in the management and marketing of organizations, highlighting certain mechanisms to improve competitive advantages for organizations.
Originality/value
The impact of social networks and Web 3.0 technology on organizations has not been analyzed in the literature. The paper also highlights the importance of community managers and crowdsourcing processes in coping with the new environment.
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Hsien‐Yu Tseng and Chang‐Ching Lin
This research aims to develop an effective and efficient algorithm for solving the curve fitting problem arising in automated manufacturing systems.
Abstract
Purpose
This research aims to develop an effective and efficient algorithm for solving the curve fitting problem arising in automated manufacturing systems.
Design/methodology/approach
This paper takes curve fitting as an optimization problem of a set of data points. Expressing the data as a function will be very effective to the data analysis and application. This paper will develop the stochastic optimization method to apply to curve fitting. The proposed method is a combination optimization method based on pattern search (PS) and simulated annealing algorithm (SA).
Findings
The proposed method is used to solve a nonlinear optimization problem and then to implement it to solve three circular arc‐fitting problems of curve fitting. Based on the analysis performed in the experimental study, the proposed algorithm has been found to be suitable for curve fitting.
Practical implications
Curve fitting is one of the basic form errors encountered in circular features. The proposed algorithm is tested and implemented by using nonlinear problem and circular data to determine the circular parameters.
Originality/value
The developed machine vision‐based approach can be an online tool for measurement of circular components in automated manufacturing systems.
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Abstract
Handling feature interaction is an unsolved issue in feature recognition approach. This paper presents a method for recognizing the presence of feature interactions. First, based on the convex hull concept, a so‐called reference face is defined. Second, by adding the reference face into the attributes adjacency graph (AAG), a modified AAG is obtained. Two general feature types, namely depression and protrusion features, are identified by the reference face. The basic features such as slots, pockets and bosses are represented by the modified AAG. Any features that remain unrecognized by the modified AAG are regarded as interacting features. The types of reference faces and feature face are also classified. Based on the kind of face classification, the interacting features are finally recognized via a process of virtual face extension and volume addition.
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Hui Wang, Jingsong Peng, Bing Zhao, Xin-Dong Zhang, Jie Yu, Yuan Li and Mao-Min Wang
Near-net-shaped processes of jet engine blade have better performance in both reducing the material waste during production and improving work reliability in service, while the…
Abstract
Purpose
Near-net-shaped processes of jet engine blade have better performance in both reducing the material waste during production and improving work reliability in service, while the geometric features of blade, both sculptured surface and thin-walled shape, make the precise machining of blade challenging and difficult owing to its dynamics behaviors under complex clamping and machining loads. This paper aims to present a fundamental approach on modeling and performance analysis of the blade–fixture system.
Design/methodology/approach
A computerized framework on the complex blade–fixture dynamic behavior has been developed. Theoretical mechanic analysis on blade fixturing and machining is proposed with an especial emphasis on the boundary conditions of the blade–fixture system. Then the finite element analysis (FEA) method is used to simulate the variation trend of preloads, stiffness and blade distortion. The strong influence of parameters of workpiece–fixture configuration on blade distortion and machining error is investigated.
Findings
With a case of real jet engine blade machining, the experimental results and theoretical predictions suggest good agreement on their variation tendency. The loaded pressure of clamps has a critical influence on the total stiff performance of the blade–fixture system, and the profile error of the blade contributes much to the inconsistency in geometric dimension and surface integrity of blades’ machining. In the end, the results also validate the effectiveness of this methodology to predict and improve the performance of the blade–fixture configuration design.
Originality/value
The adaptive machining of near-net-shaped jet engine blade is a new high-performance manufacturing technology in aerospace production. This study provides a fundamental methodology for the performance analysis of blade-fixture system, to clear the variation law of blade distortion during preloading and machining, which will contribute to minimize the machining error and improve productivity.
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Hong Xiao, Yuan Li, Jian-Feng Yu and Hui Cheng
Virtual assembly process plays an important role in assembly design of complex product and is typically time- and resource-intensive. This paper aims to investigate a dynamic…
Abstract
Purpose
Virtual assembly process plays an important role in assembly design of complex product and is typically time- and resource-intensive. This paper aims to investigate a dynamic assembly simplification approach in order to demonstrate and interact with virtual assembly process of complex product in real time.
Design/methodology/approach
The proposed approach regards the virtual assembly process of complex product as an incremental growth process of dynamic assembly. During the growth process, the current-assembled-state assembly model is simplified with appearance preserved by detecting and removing its invisible features, and the to-be-assembled components are simplified with assembly features preserved using conjugated subgraphs matching method based on an improved subgraph isomorphism algorithm.
Findings
The dynamic assembly simplification approach is applied successfully to reduce the complexity of computer aided design models during the virtual assembly process and it is proved by several cases.
Originality/value
A new assembly features definition is proposed based on the notion of “conjugation” to assist the assembly features recognition, which is a main step of the dynamic assembly simplification and has been translated into conjugated subgraphs matching problem. And an improved subgraph isomorphism algorithm is presented to address this problem.