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1 – 10 of over 2000Jasgurpreet Singh Chohan, Rupinder Singh and Kamaljit Singh Boparai
This paper aims to focus on the changes in thermal and surface characteristics of acrylonitrile butadiene styrene (ABS) material when exposed to chemical vapours for surface…
Abstract
Purpose
This paper aims to focus on the changes in thermal and surface characteristics of acrylonitrile butadiene styrene (ABS) material when exposed to chemical vapours for surface finishing. The poor surface finish and the dimensional accuracy of the fused deposition modelling parts (of ABS material) because of the stair-stepping hinder their use for rapid tooling applications, which can be improved by vapour finishing process. The differential scanning calorimetry (DSC) tests are performed to investigate the thermal behaviour of ABS thermoplastic after vapour finishing.
Design/methodology/approach
The hip prosthesis replica has been used to highlight the efficacy of chemical finishing process for intricate and complex geometries. The replicas are treated with chemical vapours for different durations. The DSC tests are performed along with surface roughness, surface hardness and dimensional measurements of exposed replicas and compared with unexposed replica.
Findings
The longer finishing time, i.e. 20 s, manifested higher melting peak temperature, higher melting enthalpy and higher heat capacity along with smoother and harder surface as compared with unexposed replica. The finishing process enhanced the bonding strength and the heat-bearing capacity of ABS material. The vapour finishing process enhanced the thermal stability of the material which may extend its sustainability at higher temperatures.
Practical implications
The improved thermal stability of ABS thermoplastic after chemical vapour finishing has been demonstrated. This advancement allows the use of ABS in functional tooling suitable for small production runs with higher flexibility and lead time savings.
Originality/value
The heat effects associated with phase transitions as a function of temperature are studied in case of replicas finished with chemical vapours. The relationship between melting enthalpy and surface characteristics has been ascertained.
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Jehn‐Ruey Jiang, Chung‐Ta King, Chi‐Shiang Liao and Ching‐Hao Liu
The purpose of this paper is to propose MUREX, a mutable replica control scheme, to keep one‐copy equivalence for synchronous replication in structured peer‐to‐peer (P2P) storage…
Abstract
Purpose
The purpose of this paper is to propose MUREX, a mutable replica control scheme, to keep one‐copy equivalence for synchronous replication in structured peer‐to‐peer (P2P) storage systems.
Design/methodology/approach
For synchronous replication in P2P networks, it is proper to adopt crash‐recovery as the fault model; that is, nodes are fail‐stop and can recover and rejoin the system after synchronizing their states with other active nodes. In addition to the state synchronization problem, the paper identifies other two problems to solve for synchronous replication in P2P storage systems. They are the replica acquisition and the replica migration problems.
Findings
On the basis of multi‐column read/write quorums, MUREX conquers the problems by the replica pointer, the on‐demand replica regeneration, and the leased lock techniques.
Originality/value
The paper proves the correctness of MUREX, analyzes and also simulates it in terms of communication cost and operation success rate.
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Ihab El‐Katatny, S.H. Masood and Y.S. Morsi
Recent advancement in fused deposition modelling (FDM) rapid prototyping technology has made it a viable technology for application in reconstructive surgery. The purpose of this…
Abstract
Purpose
Recent advancement in fused deposition modelling (FDM) rapid prototyping technology has made it a viable technology for application in reconstructive surgery. The purpose of this paper is to investigate the errors generated during the fabrication stage of complex anatomical replicas derived from computed tomography coupled with the technique of FDM.
Design/methodology/approach
An evaluation on the errors generated during the fabrication process of two anatomical parts (skull or mandible) for different human sizes (infant, female or male) is carried out. A comparison between the linear measurements of 11 landmarks on the virtual model of a skull and nine for the mandible of patient specific and its replica is conducted. Furthermore, eight landmarks are chosen to evaluate the bone thickness variation over the fabricated replicas.
Findings
Although the FDM technology proved the ability to manufacture and to fit prosthesis to a patient's unique proportions quickly and with relatively low cost, the model accuracy is a key factor to the applicability of such technology. The results show undersized replicas with an overall absolute average deviation of 0.24 per cent with an average standard deviation of 0.16 per cent of the skull models and 0.22 per cent with a 0.11 per cent standard deviation of the mandibles. Furthermore, a high level of accuracy is reflected in the representation of the measured bone thickness with deviations in the order of 100th of a millimetre being reported.
Originality/value
The paper demonstrates an outstanding accuracy using FDM process for the fabrication of anatomical replicas using models of different human sizes and gender in comparison to other established rapid prototyping techniques.
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Masoud Nosrati and Mahmood Fazlali
One of the techniques for improving the performance of distributed systems is data replication, wherein new replicas are created to provide more accessibility, fault tolerance and…
Abstract
Purpose
One of the techniques for improving the performance of distributed systems is data replication, wherein new replicas are created to provide more accessibility, fault tolerance and lower access cost of the data. In this paper, the authors propose a community-based solution for the management of data replication, based on the graph model of communication latency between computing and storage nodes. Communities are the clusters of nodes that the communication latency between the nodes are minimum values. The purpose of this study if to, by using this method, minimize the latency and access cost of the data.
Design/methodology/approach
This paper used the Louvain algorithm for finding the best communities. In the proposed algorithm, by requesting a file according to the nodes of each community, the cost of accessing the file located out of the applicant’s community was calculated and the results were accumulated. On exceeding the accumulated costs from a specified threshold, a new replica of the file was created in the applicant’s community. Besides, the number of replicas of each file should be limited to prevent the system from creating useless and redundant data.
Findings
To evaluate the method, four metrics were introduced and measured, including communication latency, response time, data access cost and data redundancy. The results indicated acceptable improvement in all of them.
Originality/value
So far, this is the first research that aims at managing the replicas via community detection algorithms. It opens many opportunities for further studies in this area.
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Zakaria Maamar, Quan Z. Sheng, Samir Tata, Djamal Benslimane and Mohamed Sellami
In any critical system, high‐availability of software components like web services has so far been achieved through replication. Three replication strategies known as active…
Abstract
Purpose
In any critical system, high‐availability of software components like web services has so far been achieved through replication. Three replication strategies known as active, passive, and hybrid, describe for example how many replicas are needed, where to locate replicas, and how replicas interact with the original web service and among themselves if needed. The purpose of this paper is to show how replicates could be substituted with components that are similarly functional to the component that needs back‐up in case of failure.
Design/methodology/approach
After examination of the different existing replication strategies, it was decided to test the suitability of the proposed web services high‐availability approach based on communities for each strategy. To this end, the specification of web services using two behaviors, namely control and operational, was deemed appropriate.
Findings
The active replication strategy is the only strategy that could support the development of a web services high‐availability approach based on communities of web services.
Practical implications
The proposed approach has been validated in practice by deploying a JXTA‐based testbed. The experimental work has implemented the active replication strategy.
Originality/value
Software component high‐availability could be achieved by components that are similarly functional to this component, which permits the common limitations of existing replication strategies to be addressed.
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Jasgurpreet Singh Chohan and Rupinder Singh
The purpose of this paper is to review the various pre-processing and post-processing approaches used to ameliorate the surface characteristics of fused deposition modelling…
Abstract
Purpose
The purpose of this paper is to review the various pre-processing and post-processing approaches used to ameliorate the surface characteristics of fused deposition modelling (FDM)-based acrylonitrile butadiene styrene (ABS) prototypes. FDM being simple and versatile additive manufacturing technique has a calibre to comply with present need of tailor-made and cost-effective products with low cycle time. But the poor surface finish and dimensional accuracy are the primary hurdles ahead the implementation of FDM for rapid casting and tooling applications.
Design/methodology/approach
The consequences and scope of FDM pre-processing and post-processing parameters have been studied independently. The comprehensive study includes dominance, limitations, validity and reach of various techniques embraced to improve surface characteristics of ABS parts. The replicas of hip implant are fabricated by maintaining the optimum pre-processing parameters as reviewed, and a case study has been executed to evaluate the capability of vapour smoothing process to enhance surface finish.
Findings
The pre-processing techniques are quite deficient when different geometries are required to be manufactured within limited time and required range of surface finish and accuracy. The post-processing techniques of surface finishing, being effective disturbs the dimensional stability and mechanical strength of parts thus incapacitates them for specific applications. The major challenge for FDM is the development of precise, automatic and controlled mass finishing techniques with low cost and time.
Research limitations/implications
The research assessed the feasibility of vapour smoothing technique for surface finishing which can make consistent castings of customized implants at low cost and shorter lead times.
Originality/value
The extensive research regarding surface finish and dimensional accuracy of FDM parts has been collected, and inferences made by study have been used to fabricate replicas to further examine advanced finishing technique of vapour smoothing.
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Studies of Tianhou-Mazu cult have been focused on three themes: studies in Taiwan emphasize hegemonic order; studies in Hong Kong reveal a relationship of “sisterhood” alliances;…
Abstract
Purpose
Studies of Tianhou-Mazu cult have been focused on three themes: studies in Taiwan emphasize hegemonic order; studies in Hong Kong reveal a relationship of “sisterhood” alliances; and studies in Singapore highlight the important role of ethnic groups. The rebuilding of the goddess’s ancestral temple in early 1980s and her acquiring a world intangible cultural heritage status in the early twenty-first century facilitate the redefinition of overseas Chinese’s religious affiliation. The purpose of this paper is to discuss this global development of the cult from the 1980s and its ritual implication in overseas Chinese communities.
Design/methodology/approach
This paper, by comparing the Tianhou-Mazu cult in Taiwan, Hong Kong and Southeast Asian Chinese settlements, argues that from sisters to descended replicas, or from local alliances to global hegemony, the cult of Tianhou-Mazu since the 1980s has not only replaced local culture with an emphasis on “high culture,” but also represents a religious strategy regarding local people’s interpretation of correctness and authority.
Findings
This paper argues that despite the imposition of hegemonic power from various authorities, popular religion is a matter of choice. This reflects how local religious practice is construed according to the interpretation of global cultural languages by the elite Chinese; their decision of when and how to reconnect with the goddess’s ancestral temple or the “imperial state,” or to form alliances with other local communities; and the implementation of the local government’s cultural policy.
Originality/value
This paper is one of the few attempts comparing development of a folk cult in various communities.
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Kristy Henson, Paul Constantino, F. Robin O’Keefe and Greg Popovich
The topic of human skeletal analysis is a sensitive subject in North America. Laws and regulations surrounding research of human skeletal material make it difficult to use these…
Abstract
Purpose
The topic of human skeletal analysis is a sensitive subject in North America. Laws and regulations surrounding research of human skeletal material make it difficult to use these remains to characterize various populations. Recent technology has the potential to solve this dilemma. Three-dimensional (3D) scanning creates virtual models of this material, and stores the information, allowing future studies on the material. The paper aims to discuss these issues.
Design/methodology/approach
To assess the potential of this methodology, the authors compared processing time, accuracy and costs of computer tomography (CT) scanner to the Artec Eva portable 3D surface scanner. Using both methodologies the authors scanned and 3D printed one adult individual. The authors hypothesize that the Artec Eva will create digital replicas of <5 percent error based on Buikstra and Ubelaker standard osteometric measurements. Error was tested by comparing the measurements of the skeletal material to the Artec data, CT data and 3D printed data.
Findings
Results show that larger bones recorded by the Artec Eva have <5 percent error of the original specimen while smaller more detailed images have >5 percent error. The CT images are closer to <5 percent accuracy, with few bones still >5 percent error. The Artec Eva scanner is inexpensive in comparison to a CT machine, but takes twice as long to process the Eva’s data. The Artec Eva is sufficient in replication of larger elements, but the CT machine is still a preferable means of skeletal replication, particularly for small elements.
Originality/value
This research paper is unique because it compares two common forms of digitization, which has not been done. The authors believe this paper would be of value to natural history curators and various researchers.
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Very little fast fashion literature focuses on pleasure‐seeking activities or luxury‐fast‐fashion and the purpose of this paper is to start addressing these gaps from the…
Abstract
Purpose
Very little fast fashion literature focuses on pleasure‐seeking activities or luxury‐fast‐fashion and the purpose of this paper is to start addressing these gaps from the perspective of the customer.
Design/methodology/approach
Over eight months, a naturalistic inquiry obtained publicly available online information from customers who during their normal daily lives freely shared their opinions and reflections about fast fashion purchases.
Findings
A clearly apparent and unexpected finding is that pleasure‐seeking consumers enjoy creativity associated with ephemeral fashions and uniqueness, as these add value to the customer in different ways, depending on whether the customer is a fast fashion or a replica customer.
Research limitations/implications
This study is limited to the fast fashion context and lays the foundation for future researchers to consider other contexts of fashion or luxury brands to qualify or quantify the extent of pleasure seeking and its contribution to the fashion experience in the context of the designer, the fashion brand and the customer.
Practical implications
Developing fashion games or fashion applications that enable the user to create and design fashion items, or mix and match fashion items will reinforce enjoyment in the design experience and linking these to the brand should reinforce positive affirmations toward the fast fashion brand.
Originality/value
This paper takes a fresh approach to uncover and describe hedonic customer responses to replica and fast fashion, the results of which update fast fashion and the luxury brand literatures and demonstrate the importance of creativity in the experience.
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A. Abdollahi Nami and L. Rajabion
A mobile ad hoc network (MANET) enables providers and customers to communicate without a fixed infrastructure. Databases are extended on MANETs to have easy data access and…
Abstract
Purpose
A mobile ad hoc network (MANET) enables providers and customers to communicate without a fixed infrastructure. Databases are extended on MANETs to have easy data access and update. As the energy and mobility limitations of both servers and clients affect the availability of data in MANETs, these data are replicated. The purpose of this paper is to provide a literature review of data replication issues and classify the available strategies based on the issues they addressed.
Design/methodology/approach
The selected articles are reviewed based on the defined criteria. Also, the differences, the advantages and disadvantages of these techniques are described. The methods in the literature can be categorized into three groups, including cluster-based, location-based and group-based mechanisms.
Findings
High flexibility and data consistency are the features of cluster-based mechanisms. The location-based mechanisms are also appropriate for replica allocation, and they mostly have low network traffic and delay. Also, the group-based mechanism has high data accessibility compared to other mechanisms. Data accessibility and time have got more attention to data replication techniques. Scalability as an important parameter must be considered more in the future. The reduction of storage cost in MANETs is the main goal of data replication. Researchers have to consider the cost parameter when another parameter will be influenced.
Research limitations/implications
Data replication in MANETs has been covered in different available sources such as Web pages, technical reports, academic publications and editorial notes. The articles published in national journals and conferences are ignored in this study. This study includes articles from academic main international journals to get the best capability.
Originality/value
The paper reviews the past and the state-of-the-art mechanisms in data replication in MANET. Exclusively, data replication’s main goal, existing challenges, research terminologies and mechanisms in MANET are summarized using the answers to the research questions. This method will help researchers in the future to develop more effective data replication method in MANET.
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