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Article
Publication date: 1 August 2003

Xiuzhi Qu and Brent Stucker

This paper presents a new 3D offset method for modifying CAD model data in the STL format. In this method, vertices, instead of facets, are offset. The magnitude and…

Abstract

This paper presents a new 3D offset method for modifying CAD model data in the STL format. In this method, vertices, instead of facets, are offset. The magnitude and direction of each vertex offset is calculated using the weighted sum of the normals of the facets that are connected to each vertex. To facilitate the vertex offset calculation, topological information is generated from the collection of unordered triangular facets making up the STL file. A straightforward algorithm is used to calculate the vertex offset using the adjoining facet normals, as identified from the topological information. This newly developed technique can successfully generate inward or outward offsets for STL models. As with any offset methodology, this technique has benefits and drawbacks, which will be discussed in this paper. Finally, conclusions will be made regarding the applicability of the developed methodology.

Details

Rapid Prototyping Journal, vol. 9 no. 3
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 July 2004

Zhang Zhengyu, Ding Yucheng and Hong Jun

A new method of hollowing rapid prototype models based on STL models and their cross‐sectional contours is presented to meet the demands of hollowed prototypes in casting…

Abstract

A new method of hollowing rapid prototype models based on STL models and their cross‐sectional contours is presented to meet the demands of hollowed prototypes in casting and rapid prototype manufacturing. Offsetting along the Z‐axis and cross‐sectional contour offsetting are employed to perform the hollowing operation. The process performs two‐dimensional Boolean operations on the polygons made by the offset contours of cross‐sectional contours instead of three‐dimensional offsetting of the STL models. This hollowing operation is especially suitable for hollowing STL models with free‐form surfaces. Detailed algorithms are described to generate the correct offset contours of an STL model. Adopting this method, the hollowing process is dramatically simplified and becomes more efficient. This method has been verified by practical case studies, and it is proved that this simplified hollowing operation can reduce the prototype build time and cost.

Details

Rapid Prototyping Journal, vol. 10 no. 3
Type: Research Article
ISSN: 1355-2546

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Book part
Publication date: 2 September 2019

Alice Valiergue

The chapter studies the functioning of the so-called “voluntary” carbon offset market, a market in which moral controversies take place. The analysis dwells on the…

Abstract

The chapter studies the functioning of the so-called “voluntary” carbon offset market, a market in which moral controversies take place. The analysis dwells on the theoretical framework that enables us to study the functioning of a contested market through particular devices. The chapter seeks to contribute to the literature on moral struggles within markets by focusing the attention on one specific device: relational work, including several dimensions like meeting between seller and buyer, establishing contracts and maintaining the relationship with clients in the long run. By studying relational work, the authors highlight how this basic market activity is a crucial device that makes it possible for a contested market to continue to exist.

Details

The Contested Moralities of Markets
Type: Book
ISBN: 978-1-78769-120-9

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Book part
Publication date: 14 August 2014

Gueorgui Ianakiev

The use of offsets is one of the main characteristics of international defence trade. The rising costs of defence equipment and the significant contraction of defence…

Abstract

The use of offsets is one of the main characteristics of international defence trade. The rising costs of defence equipment and the significant contraction of defence spending have resulted in an environment that favoured the use of offset policies, the latter becoming increasingly demanding in both quantitative and qualitative terms. The chapter analyses the role of offsets on the process of integration of defence equipment markets, with a specific focus on the EU. Particular attention is given to the offset-relevant regulation and practice and to their recent evolution in the EU following the adoption of European Directive on defence and security procurement (81/81/EC). Offsets play a dual role with regard to the integration of defence industries: on one hand they can be trade-distorting and contribute to the survival of inefficient suppliers in arms importing countries; on the other hand, they can contribute in overcoming barriers that may otherwise prevent some potentially efficient suppliers from accessing the supply chains of the big system integrators. The chapter draws the attention on the need to complement the regulatory evolution by further initiatives aiming at improving the access of non-incumbent suppliers to the supply chains of the large defence system integrators.

Details

The Evolving Boundaries of Defence: An Assessment of Recent Shifts in Defence Activities
Type: Book
ISBN: 978-1-78350-965-2

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Article
Publication date: 4 November 2014

Kanwalroop Kathy Dhanda

This paper aims to explore the area of carbon offsets and carbon neutrality within the context of hotels and resorts. In theory, carbon markets assist organizations in…

Abstract

Purpose

This paper aims to explore the area of carbon offsets and carbon neutrality within the context of hotels and resorts. In theory, carbon markets assist organizations in reducing their carbon footprint by purchasing carbon offsets. This conceptual paper aims to explore this market, analyze its operations and evaluate the participants. The expectation is that this original research will provide a foundation for analyzing this market to make sense of the widely disparate views about carbon neutrality held by companies in the hospitality sector.

Design/methodology/approach

The research study aimed to uncover what claims are currently made about carbon neutrality, what properties are making these claims and are these claims legitimate? A broad Internet search was conducted to collect a sample of hotels and resorts that marketed carbon neutrality as a feature of their properties. Next, a five-point Likert type scale was constructed to analyze every hotel and resort in terms of legitimate reflection of market performance challenges or dimensions. In this study, the hotels that claim to be “Carbon Neutral” were scored according to four market performance dimensions: project quality, carbon calculations, quality information of providers and price per ton of carbon offset.

Findings

The paper’s findings offer a twofold contribution. First, hotels and resorts interested in entering the offset market can use the results as strategic information to bolster efforts to achieve legitimacy and viability in this market. Second, the findings offer a benefit to consumers concerned to reduce their carbon footprint, as the results include a determination of the best hotels and resorts in terms of carbon neutrality.

Research limitations/implications

This research found that the claim “carbon neutral” is used often to attract green consumers. The spectrum of claims ranged from hotels presenting comprehensive carbon management plans or online carbon footprint applications, to hotels that had minimal information and used the “carbon neutral” for marketing purposes only. In numerous cases, the claim of carbon neutrality is not substantiated and, in this case, might be construed as greenwashing.

Practical implications

The findings indicate that claims of carbon neutrality can be exaggerated and that the consumers must themselves be educated to be aware of claims that are unfounded.

Originality/value

Given the large and rising number of offset providers in the unregulated carbon offset industry and the hotel industry, this contribution promises to offer value. This study is one of the first formal analyses of carbon offsets in the hospitality market. The author hopes that this study will encourage others to research the growing market of voluntary carbon offsets further.

Details

International Journal of Contemporary Hospitality Management, vol. 26 no. 8
Type: Research Article
ISSN: 0959-6119

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Article
Publication date: 8 August 2019

Thomas Cuckston

The purpose of this paper is to explain how proponents of biodiversity offsetting have sought to produce an ecologically defensible mechanism for reconciling economic…

Abstract

Purpose

The purpose of this paper is to explain how proponents of biodiversity offsetting have sought to produce an ecologically defensible mechanism for reconciling economic development and biodiversity conservation.

Design/methodology/approach

The paper analyses a case study biodiversity offsetting mechanism in New South Wales, Australia. Michel Callon’s framing and overflowing metaphor is used to explain how accounting devices are brought into the mechanism, to (re)frame a space of calculability and address anxieties expressed by conservationists about calculations of net loss/gain of biodiversity.

Findings

The analysis shows that the offsetting mechanism embeds a form of accounting for biodiversity that runs counter to the prevailing dominant anthropocentric approach. Rather than accounting for the biodiversity of a site in terms of the economic benefits it provides to humans, the mechanism accounts for biodiversity in terms of its ecological value. This analysis, therefore, reveals a form of accounting for biodiversity that uses numbers to provide valuations of biodiversity, but these numbers are ecological numbers, not economic numbers. So this is a calculative, and also ecocentric, approach to accounting for, and valuing, biodiversity.

Originality/value

This paper contributes to the extant literature on accounting for biodiversity by revealing a novel conceptualisation of the reconciliation of economic development and biodiversity conservation, producing an ecologically defensible form of sustainable development. The paper also makes a methodological contribution by showing how Callon’s framing and overflowing metaphor can be used to enable the kind of interdisciplinary engagement needed for researchers to address sustainable development challenges.

Details

Accounting, Auditing & Accountability Journal, vol. 32 no. 5
Type: Research Article
ISSN: 0951-3574

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Article
Publication date: 14 June 2013

Helen Tregidga

The paper aims to analyse accounting rationalities and practices which lie behind biodiversity offsetting. The way in which accounting functions as a technology of…

Abstract

Purpose

The paper aims to analyse accounting rationalities and practices which lie behind biodiversity offsetting. The way in which accounting functions as a technology of government through the practice of biodiversity offsetting is to be considered and its effects examined.

Design/methodology/approach

Governmentality is drawn upon to examine ways in which power and authority are exercised in a single case study setting. Data analysed comprise corporate and industry websites and documents, corporate reports, public documentation and interviews. The arena concept is utilised to highlight contestation in the case, and signal concerns regarding the wider impact of the use of particular accounting rationalities and technologies in the context of biodiversity offsetting.

Findings

The paper provides empirical insights into how accounting for biodiversity offsetting rationales and practices constitute an attempt to reproduce power relations in favour of particular parties and foster disciplinary effects. The practice of biodiversity offsetting is problematised through critiquing accounting's governing role in the areas of biodiversity quantification and biodiversity trading. Questions are raised as to whether biodiversity offsetting enabled by accounting techniques is leading to greater accountability and ultimately protection of biodiversity, or whether it represents a mechanism through which particular species and habitat destruction can be justified, or at least hidden in its accounting.

Originality/value

While biodiversity offsetting research is not uncommon within science and law, the analysis of how accounting functions as a technology of government within biodiversity offsetting is believed to be unique.

Details

Accounting, Auditing & Accountability Journal, vol. 26 no. 5
Type: Research Article
ISSN: 0951-3574

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Article
Publication date: 1 September 1999

Xiangwei Wang

Selective laser sintering (SLS) is one of the most successful rapid tooling processes. Shrinkage and beam offset are the two most important control parameters in this…

Abstract

Selective laser sintering (SLS) is one of the most successful rapid tooling processes. Shrinkage and beam offset are the two most important control parameters in this process. First, the SLS process and procedure of calibration are described. Second, based on the property of shrinkage and beam offset, a basic formula of shrinkage and beam offset is derived. Finally, the procedure of applying shrinkage (scaling factor) and beam offset is described.

Details

Rapid Prototyping Journal, vol. 5 no. 3
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 17 May 2011

Kelly A. Stevens, Greg DeAngelo and Shenita Brice

The paper is an excerpt from a more comprehensive study by the Florida Department of Environmental Protection comparing the technical elements of offset projects in…

Abstract

Purpose

The paper is an excerpt from a more comprehensive study by the Florida Department of Environmental Protection comparing the technical elements of offset projects in forestry, agriculture, and waste management, as well as some miscellaneous project types. The authors compare and contrast design elements of three specific offset projects: afforestation/reforestation, manure management, and landfill gas capture. The technical review for each offset project is concluded with a look at the potential applicability for that project in Florida in the context of the protocols evaluated.

Design/methodology/approach

Offset projects that may be employed in Florida are first broken up into comparable design elements specific to the selected offset project type. Focusing on the design elements, a discussion of the similarities and differences among the protocols for each offset project is presented. Each section begins with general findings then moves on to assessments of the detailed design elements. Finally, the project's general applicability to Florida is considered, highlighting specific strengths of particular protocols from the analysis of the design elements.

Findings

Protocols tend to vary from highly specific requirements to a more general set of recommendations. Interestingly, no one program's set of protocols is the most opportunistic for Florida, but rather various protocols may have distinctive strengths depending on the project type.

Originality/value

Many comparative studies of offset protocols evaluate protocols in the context of program‐level policies. This study uniquely values the technical details in the protocols and does not consider policy or program‐level issues.

Details

International Journal of Climate Change Strategies and Management, vol. 3 no. 2
Type: Research Article
ISSN: 1756-8692

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Article
Publication date: 18 April 2016

Hao Wen, Jian Gao and Xin Chen

As manufacturing technology has developed, digital models from advanced measuring devices have been widely used in manufacturing sectors. To speed up the production cycle…

Abstract

Purpose

As manufacturing technology has developed, digital models from advanced measuring devices have been widely used in manufacturing sectors. To speed up the production cycle and reduce extra errors introduced in surface reconstruction processes, directly machining digital models in the polygonal stereolithographyformat has been considered as an effective approach in rapid digital manufacturing. In machining processes, Cutter Location (CL) data for numerical control (NC) machining is generated usually from an offset model. This model is created by offsetting each vertex of the original model along its vertex vector. However, this method has the drawback of overcut to the offset model. The purpose of this paper is to solve the overcut problem through an error compensation algorithm to the vertex offset model.

Design/methodology/approach

Based on the analysis of the vertex offset method and the offset model generated, the authors developed and implemented an error compensation method to correct the offset models and generated the accurate CL data for the subsequent machining process. This error compensation method is verified through three polygonal models and the tool paths generated were used for a real part machining.

Findings

Based on the analysis of the vertex offset method and the offset model generated, the authors developed an error compensation method to correct the offset models and generated the accurate CL data for the subsequent machining process. The developed error compensation algorithm can effectively solve the overcut drawback of the vertex offset method.

Research limitations/implications

The error compensation method to the vertex offset model is used for generating the CL data with the using of a ball-end cutter.

Practical implications

On the study of CL data generation for a STL model, most of the current studies are focused on the determination of the offset vectors of the vertexes. The offset distance is usually fixed to the radius of the cutter used. Thus, the overcut problem to the offset model is inevitable and has not been much studied. The authors propose an effective approach to compensate the insufficient distance of the offset vertex and solve the overcut problem.

Social implications

The directly tool paths generation from a STL model can reduce the error of surface reconstruction and speed up the machining progress.

Originality/value

The authors investigate the overcut problem occurred in vertex offset for CL data generation and present a new error compensation algorithm for generating the CL data that can effectively solve the overcut problem.

Details

Rapid Prototyping Journal, vol. 22 no. 3
Type: Research Article
ISSN: 1355-2546

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