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Article
Publication date: 1 December 2004

Wei Sun, Tao Jiang and Feng Lin

A processing algorithm for freeform fabrication of heterogeneous structures is presented. The algorithm was developed based on the heterogeneous fabrication structural…

Abstract

A processing algorithm for freeform fabrication of heterogeneous structures is presented. The algorithm was developed based on the heterogeneous fabrication structural model, which was constructed from the STL based multi‐material volume regions and with material identifications. The reasoning Boolean operation based modelling approach was used to construct the heterogeneous CAD assembly and to output the needed STL format. Procedures for generating the database hierarchy and the storage of the heterogeneous structural model, and derivation for developing the processing algorithm for layered fabrication of heterogeneous structure are presented. The developed algorithm was applied to a heterogeneous structure consisting of two discrete material volumes, and the detailed processing path is described.

Details

Rapid Prototyping Journal, vol. 10 no. 5
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 6 August 2020

Mao He, Juncheng Huang and Hongquan Zhu

The purpose of our study is to explore the “idiosyncratic volatility puzzle” in Chinese stock market from the perspective of investors' heterogeneous beliefs. To delve…

Abstract

Purpose

The purpose of our study is to explore the “idiosyncratic volatility puzzle” in Chinese stock market from the perspective of investors' heterogeneous beliefs. To delve into the relationship between idiosyncratic volatility and investors' heterogeneous beliefs, and uncover the ability of heterogeneous beliefs, as well as to explain the “idiosyncratic volatility puzzle”, we construct our study as follows.

Design/methodology/approach

Our study adopts the unexpected trading volume as proxies of heterogeneity, the residual of Fama–French three-factor model as proxies of idiosyncratic volatility. Portfolio strategies and Fama–MacBeth regression are used to investigate the relationship between the two proxies and stock returns in Chinese A-share market.

Findings

Investors' heterogeneous beliefs, as an intermediary variable, are positively correlated with idiosyncratic volatility. Meanwhile, it could better demonstrate the negative correlation between the idiosyncratic volatility and future stock returns. It is one of the economic mechanisms linking idiosyncratic volatility to subsequent stock returns, which can account for 11.28% of the puzzle.

Originality/value

The findings indicate that idiosyncratic volatility is significantly and positively correlated with heterogeneous beliefs and that heterogeneous beliefs are effective intervening variables to explain the “idiosyncratic volatility puzzle”.

Details

China Finance Review International, vol. 11 no. 1
Type: Research Article
ISSN: 2044-1398

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Article
Publication date: 1 April 2005

Xiaojun Wu, Weijun Liu and Michael Yu Wang

The representation of Heterogeneous Object (HO) is divided into two categories: Data model (DM) and material evaluation paradigm (MEP). A hybrid methodology with geometry…

Abstract

The representation of Heterogeneous Object (HO) is divided into two categories: Data model (DM) and material evaluation paradigm (MEP). A hybrid methodology with geometry model and volumetric dataset to represent heterogeneous properties is proposed in this paper. Geometry model of an object can guarantee the accuracy of the final HO slices; and volumetric dataset lends the flexible manipulability and other advantages to HO representation. Two MEPs, namely distance field (DF) based and Fixed Reference Features & Active Grading Source(s) (FRF&AGS) are presented to facilitate the process of HO representation according to the designer)s input parameters. The DM can be modified interactively with users until the final satisfactory result is obtained. In this paper, a scheme of HO slicing is described. In this method, we utilize the slices contour of geometrical model as constraint to reconstruct the HO slices, which can theoretically achieve the same accuracy with the geometrical shape. Some examples of Heterogeneous object represented with our scheme are provided.

Details

Multidiscipline Modeling in Materials and Structures, vol. 1 no. 4
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 16 January 2009

X.Y. Kou and S.T. Tan

Apart from the geometries to be dealt with, rapid prototyping (RP) of heterogeneous objects requires additional material information to be processed. This generally…

Abstract

Purpose

Apart from the geometries to be dealt with, rapid prototyping (RP) of heterogeneous objects requires additional material information to be processed. This generally involves a large amount of information to be processed simultaneously. The robustness and efficiency problems, which seem less critical in homogeneous solid fabrications, become an issue. The direct impetus of this paper is to present robust and efficient algorithms for RP of heterogeneous objects.

Design/methodology/approach

The robustness is benefited from using the proposed non‐manifold heterogeneous cellular model, which guarantees gap‐free material depositions around material interfaces. The efficiency enhancement is achieved by eliminating repetitive boundary intersections and using a heuristic material interrogation approach.

Findings

By using the proposed algorithms, the robustness and efficiency of RP of heterogeneous objects can be improved. It is found that an average 30 percent efficiency improvement is obtained using the proposed heuristic material interrogation approach.

Originality/value

Non‐manifold heterogeneous cell representation (HC‐Rep) is used in RP fields for the first time. Based on the HC‐Rep, the robustness and efficiency of RP of heterogeneous object is addressed in this paper.

Details

Rapid Prototyping Journal, vol. 15 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 June 2000

Srinivas Bhashyam, Ki Hoon Shin and Debashish Dutta

Computer aided design systems are routinely used by designers for creating part geometries. Interfaces to computer aided analysis and manufacturing are also commonplace…

Abstract

Computer aided design systems are routinely used by designers for creating part geometries. Interfaces to computer aided analysis and manufacturing are also commonplace enabling the rapid fabrication of the designed part. Thus far, however, the focus was on objects with homogeneous interior. Two recent advances use of functionally graded materials in parts, and layered manufacturing technology have brought to the forefront the need for CAD systems to support the creation of geometry as well as the graded material inside. This paper reports on such a system. We describe the need, the components and implementation of a CAD system for creating heterogeneous objects. Two examples illustrate the use.

Details

Rapid Prototyping Journal, vol. 6 no. 2
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 6 March 2017

Xiaodong Wang and Jianfeng Cai

For some specific multi-criteria decision-making (MCDM) problems, especially in emergency situations, because of the feature of criteria and other fuzzy factors, it is…

Abstract

Purpose

For some specific multi-criteria decision-making (MCDM) problems, especially in emergency situations, because of the feature of criteria and other fuzzy factors, it is more appropriate that values of different criteria are expressed in their correspondingly appropriate value types. The purpose of this paper is to build a multi-criteria group decision-making (MCGDM) model dealing with heterogeneous information based on distance-based VIKOR to solve emergency supplier selection in practice appropriately and flexibly, where a compromise solution is more acceptable and suitable.

Design/methodology/approach

This paper extends the classical VIKOR to a generalized distance-based VIKOR to handle heterogeneous information containing crisp number, interval number, intuitionistic fuzzy number and hesitant fuzzy linguistic value, and develops an MCGDM model based on the distance-based VIKOR to handle the multi-criteria heterogeneous information in practice. This paper also introduces a parameter called non-fuzzy degree for each type of heterogeneous value to moderate the computation on aggregating heterogeneous hybrid distances.

Findings

The proposed distance-based model can handle the heterogeneous information appropriately and flexibly because the computational process is directly operated on the heterogeneous information based on generalized distance without a transformation process, which can improve the decision-making efficiency and reduce information loss. An example of emergency supplier selection is given to illustrate the proposed method.

Originality/value

This paper develops an MCGDM model based on the distance-based VIKOR to handle heterogeneous information appropriately and flexibly. In emergency supplier selection situations, the proposed decision-making model allows the decision-makers to express their judgments on criteria in their appropriate value types.

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Article
Publication date: 18 December 2020

Martin Carlsson-Wall, Adrian Iredahl, Kalle Kraus and Mats Wiklund

This paper aims to explore the role of management controls in managing heterogeneous interests during extreme situations.

Abstract

Purpose

This paper aims to explore the role of management controls in managing heterogeneous interests during extreme situations.

Design/methodology/approach

Through interviews and observations, the authors analyse the Swedish Migration Agency’s management controls and study routines during the peak of the European Migrant Crisis.

Findings

Prior to the crisis, the strategy used by the employees was to mediate between two interests (labelled legal security and empathy) to create a workable compromise. During the crisis, however, the authors observed filtering in the form of the previous hierarchical ordering of interests was further strengthened as the employees increasingly relied on just a single interest (the interest which they previously had deemed to be the most important) at the expense of the other interest. The findings suggest that behavioural and social controls helped such filtering; social controls helped certain employees to filter the empathy interest as more important during extreme situations and behavioural controls helped other employees to filter the legal security interest as more important. This help us explain why the authors observe less mediation between the two heterogeneous interests and rather a stricter dominance of one of the interests. The authors also illustrate how especially behavioural controls may become unsupportive of the operations during extreme situations as it consisted of rule-based standards, built to cope with “normal” situations. The heterogeneous interests affected the probability of actors, at times, ignoring behavioural controls when such controls were unsupportive. Actors whose day-to-day operations were mainly guided by the legal security interest remained tightly coupled to behavioural controls even when they felt that these controls were no longer useful. On the other hand, actors who were mainly guided by the empathy interest ignored behavioural controls when they felt that they were unsupportive.

Research limitations/implications

The authors acknowledge that bias might arise from the reliance on retrospective views of past processes and events, which the authors primarily gathered through interviews.

Practical implications

The authors highlight an important relationship between heterogeneous interests (i.e. legal security and empathy) and management controls during the crisis and how this relationship can lead actors to fundamentally different actions.

Originality/value

The two bodies of study on the role of management controls in managing heterogeneous interests and the role of management controls during the crisis have been largely unconnected and it is in this intersection that this study contributes.

Details

Qualitative Research in Accounting & Management, vol. 18 no. 1
Type: Research Article
ISSN: 1176-6093

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Article
Publication date: 30 September 2019

Bin Li, Jianzhong Fu, Yongjie Jessica Zhang, Weiyi Lin, Jiawei Feng and Ce Shang

Majority of the existing direct slicing methods have generated precise slicing contours from different surface representations, they do not carry any interior information…

Abstract

Purpose

Majority of the existing direct slicing methods have generated precise slicing contours from different surface representations, they do not carry any interior information. Whereas, heterogeneous solids are highly preferable for designing and manufacturing sophisticated models. To directly slice heterogeneous solids for additive manufacturing (AM), this study aims to present an algorithm using octree-based subdivision and trivariate T-splines.

Design/methodology/approach

This paper presents a direct slicing algorithm for heterogeneous solids using T-splines, which can be applied to AM based on the fused deposition modeling (FDM) technology. First, trivariate T-splines are constructed using a harmonic field with the gradient direction aligning with the slicing direction. An octree-based subdivision algorithm is then used to directly generate the sliced layers with heterogeneous materials. For FDM-based AM applications, the heterogeneous materials of each sliced layer are discretized into a finite number of partitions. Finally, boundary contours of each separated partition are extracted and paired according to the rules of CuraEngine to generate the scan path for FDM machines equipped with multi-nozzles.

Findings

The experimental results demonstrate that the proposed algorithm is effective and reliable, especially for solid objects with multiple materials, which could maintain the model integrity throughout the process from the original representation to the final product in AM.

Originality/value

Directly slicing heterogeneous solid using trivariate T-splines will be a powerful supplement to current technologies in AM.

Details

Rapid Prototyping Journal, vol. 26 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 February 2002

Oluremi B. Ayoko, Charmine E.J. Härtel and Victor J. Callan

This study presents an investigation of the communicative behaviors and strategies employed in the stimulation and management of productive and destructive conflict in…

Abstract

This study presents an investigation of the communicative behaviors and strategies employed in the stimulation and management of productive and destructive conflict in culturally heterogeneous workgroups. Using communication accommodation theory (CAT), we argue that the type and course of conflict in culturally heterogeneous workgroups is impacted by the communicative behaviors and strategies employed by group members during interactions. Analysis of data from participant observations, non‐participant observations, semi‐structured interviews, and self‐report questionnaires support CAT‐based predictions and provide fresh insights into the triggers and management strategies associated with conflict in culturally heterogeneous workgroups. In particular, results indicated that the more groups used discourse management strategies, the more they experienced productive conflict. In addition, the use of explanation and checking of own and others' understanding was a major feature of productive conflict, while speech interruptions emerged as a strategy leading to potential destructive conflict. Groups where leaders emerged and assisted in reversing communication breakdowns were better able to manage their discourse, and achieved consensus on task processes. Contributions to the understanding of the triggers and the management of productive conflict in culturally heterogeneous workgroups are discussed.

Details

International Journal of Conflict Management, vol. 13 no. 2
Type: Research Article
ISSN: 1044-4068

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Article
Publication date: 1 August 2002

Lalit Patil, Debasish Dutta, A.D. Bhatt, K. Jurrens, K. Lyons, M.J. Pratt and R.D. Sriram

Information models for the representation of product data are being developed as an international standard. However, the current application protocols focus on the…

Abstract

Information models for the representation of product data are being developed as an international standard. However, the current application protocols focus on the representation of homogeneous objects only. This paper suggests an information model to represent heterogeneous objects using the information modeling methodology developed for ISO 10303. The data planning model is then extended to represent the two‐dimensional (2D) slice information using concepts from ISO 10303. The proposed formats are validated by physical realization of objects on two LM machines. This information model will help in providing a uniform base in the development of heterogeneous solid modeling systems. It will also equip the solid modeler with the ability to integrate with other applications and process planning in the domain of layered manufacturing.

Details

Rapid Prototyping Journal, vol. 8 no. 3
Type: Research Article
ISSN: 1355-2546

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