Charlie C.L. Wang and Yong Chen
Given an intersection-free mesh surface S, the paper introduces a method to thicken S into a solid H located at one side of S. By such a surface-to-solid conversion operation…
Abstract
Purpose
Given an intersection-free mesh surface S, the paper introduces a method to thicken S into a solid H located at one side of S. By such a surface-to-solid conversion operation, industrial users are able to fabricate a designed (or reconstructed) surface by rapid prototyping.
Design/methodology/approach
The paper first investigates an implicit representation of the thickened solid H according to an extension of signed distance function. After that, a partial surface reconstruction algorithm is proposed to generate the boundary surface of H, which retains the given surface S on the resultant surface.
Findings
Experimental tests show that the thickening results generated by the method give nearly uniform thickness and meanwhile do not present shape approximation error at the region of input surface S. These two good properties are important to the industrial applications of solid fabrication.
Research limitations/implications
The input polygonal model is assumed to be intersection-free, where models containing self-intersection will lead to invalid thickening results.
Originality/value
A novel robust operation is to convert a freeform open surface into a solid by introducing no shape approximation error. A new implicit function gives a compact mathematical representation, which can easily handle the topological change on the thickened solids. A new polygonization algorithm generates faces for the boundary of thickened solid meanwhile retaining faces on the input open mesh.
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Kai-Ming Yu, Yu Wang and Charlie C.L. Wang
In the newly released ASTM standard specification for additive manufacturing file (AMF) format – version 1.1 – Hermite curve-based interpolation is used to refine input triangles…
Abstract
Purpose
In the newly released ASTM standard specification for additive manufacturing file (AMF) format – version 1.1 – Hermite curve-based interpolation is used to refine input triangles to generate denser mesh with smoother geometry. This paper aims to study the problems of constructing smooth geometry based on Hermite interpolation on curves and proposes a solution to overcome these problems.
Design/methodology/approach
A formulation using triangular Bézier patch is proposed to generate smooth geometry from input polygonal models. Different configurations on the boundary curves in the formulation are analyzed to further enrich this formulation.
Findings
The study shows that the formulation given in the AMF format (version 1.1) can lead to the problems of inconsistent normals and undefined end-tangents.
Research limitations/implications
The scheme has requirements on the input normals of a model, only C0 interpolation can be generated on those cases with less-proper input.
Originality/value
To overcome the problems of smooth geometry generation in the AMF format, the authors propose an enriched scheme for computing smooth geometry by using triangular Bézier patch. For the configurations with less-proper input, the authors adopt the Boolean sum and the Nielson’s point-opposite edge interpolation for triangular Coons patch to generate the smooth geometry as a C0 interpolant.
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Yong Chen and Charlie C.L. Wang
Most layer‐based rapid prototyping systems use polygonal models as input. In addition, the input polygonal models need to be manifold and water‐tight; otherwise the built objects…
Abstract
Purpose
Most layer‐based rapid prototyping systems use polygonal models as input. In addition, the input polygonal models need to be manifold and water‐tight; otherwise the built objects may have defects or the building process may fail in some cases. This paper aims to present a regulation method of an arbitrarily complex polygonal model for rapid prototyping and manufacturing applications.
Design/methodology/approach
The method is based on a semi‐implicit representation of a solid model named the layered depth‐normal images (LDNI), which sparsely encodes the shape boundary of a polygonal model in three orthogonal directions. In the method, input polygonal models or parametric equations are first converted into LDNI models. A regulation operator based on the computed LDNI models is presented. A volume tiling technique is developed for very complex geometries and high accuracy requirements. From the processed LDNI model, an adaptive contouring method is presented to construct a cell representation that includes both uniform and octree cells. Finally, two‐manifold and water‐tight polygonal mesh surfaces are constructed from the cell representation.
Findings
The LDNI‐based mesh regulation operation can be robust due to its simplicity. The accuracy of the generated regulated models can be controlled by setting LDNI pixel width. Parallel computing techniques can be employed to accelerate the computation in the LDNI‐based method. Experimental results on various CAD models demonstrate the effectiveness and efficiency of our approach for complex geometries.
Research limitations/implications
The input polygonal model is assumed to be closed in our method. The regulated polygonal model based on our method may have a big file size.
Originality/value
A novel mesh regulation method is presented in this paper. The method is suitable for rapid prototyping and manufacturing applications by achieving a balance between simplicity, robustness, accuracy, speed and scalability. This research contributes to the additive manufacturing development by providing a digital data preparation method and related tools.
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Charlie C.L. Wang, Allan K.K. Chan and Zhen Xiong Chen
This study employed psychological variables such as consumer sentiment and attitude to debt as complementary measures to traditionally used consumer demographic or economic…
Abstract
This study employed psychological variables such as consumer sentiment and attitude to debt as complementary measures to traditionally used consumer demographic or economic variables in predicting housing purchase intention with a consumer sample in China. The result indicates that psychological factors add incremental explanatory and predictive power to traditionally used demographic variables. Results from discriminant analysis showed that, except for household income level, psychological factors were better than demographic variables in differentiating intenders from non‐intenders in China’s emerging property market. Conceptual contributions and managerial implications of the study are discussed.
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Robert Houmes, Charlie Chulee Jun, Kim Capriotti and Daphne Wang
This study aims to investigate the relations between long-window stock returns and prior years’ increases in DuPont identity components: profit margin and asset turnover. In…
Abstract
Purpose
This study aims to investigate the relations between long-window stock returns and prior years’ increases in DuPont identity components: profit margin and asset turnover. In particular, the authors examine the relative effectiveness of profit margin and asset turnover to predict years ahead stock returns.
Design/methodology/approach
To test the assertions, the authors regress raw, Capital Asset Pricing Model and Fama-French returns on controls and variables of interest, profit margin and asset turnover, lagged years t − 1, t − 2 and t − 3. To control for factors that could affect returns over the long windows, they also include returns lagged over years t − 1, t − 2 and t − 3 to coincide with the lagged profit margin and asset turnover variables of interest.
Findings
Results show a negative (positive) relation between returns and increases in lagged profit margin (asset turnover). However, the negative returns-profit margin relation is mitigated when increases in profit margin and asset turnover occur in the same lagged year.
Originality/value
This study adds to the existing body of research on the DuPont identity by temporally evaluating the relative long-run contributions of profit margin and asset turnover to firm value.
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A creative identity, the incorporation of creativity into self-definition, is associated with creative outcomes. Given the importance of creativity to organizational success…
Abstract
A creative identity, the incorporation of creativity into self-definition, is associated with creative outcomes. Given the importance of creativity to organizational success, understanding creative identity and in particular creative identity work (the formation and maintenance of creative identity) can be useful in understanding creatives within organizations. To be considered creative, individuals need to not only produce unique artefacts, but these artefacts need to be assessed by legitimate judges as being creative. Judges may be within an organization (e.g., senior researchers within a laboratory) or may be external to an organization (e.g., award judges in international advertising competitions). Underpinning creative identity work is the creative assessment, however this assessment is ambiguous and contextual. In other words, what is considered creative in one context or by one judge may not be considered creative in another context or by different judges. The ambiguity of the creative assessment makes creative identity work a precarious undertaking. Based on two case studies – a R&D laboratory and an advertising agency – this research explores the strategies which creative individuals employ in their creative identity work in response to the ambiguity of the creative assessment. This research contributes to the growing area of creative identity research by unpacking three specific strategies used as part of identity work of creatives: defending, emotional distancing and differentiating. These strategies assist the creatives in maintaining a coherent sense of who they are within the organizational context despite the unpredictability of the creative assessment.
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Mary E. Graham and Charlie O. Trevor
The design and introduction of new pay programs may be particularly challenging for multinational corporations (MNCs) because, given their diverse employee base, they face varied…
Abstract
The design and introduction of new pay programs may be particularly challenging for multinational corporations (MNCs) because, given their diverse employee base, they face varied employee expectations regarding pay. We offer a model of how national cultural norms affect employee expectations for, and judgments about, pay fairness. We also describe how firms can best use two international compensation strategies for MNCs (a global integration strategy and a local responsiveness strategy) to optimize employees' justice judgments regarding new pay programs. More favorable justice judgments should improve the chances of new pay program survival and, subsequently, contribute to firm competitiveness.
John F. Sacco and Gerard R. Busheé
This paper analyzes the impact of economic downturns on the revenue and expense sides of city financing for the period 2003 to 2009 using a convenience sample of the audited end…
Abstract
This paper analyzes the impact of economic downturns on the revenue and expense sides of city financing for the period 2003 to 2009 using a convenience sample of the audited end of year financial reports for thirty midsized US cities. The analysis focuses on whether and how quickly and how extensively revenue and spending directions from past years are altered by recessions. A seven year series of Comprehensive Annual Financial Report (CAFR) data serves to explore whether citiesʼ revenues and spending, especially the traditional property tax and core functions such as public safety and infrastructure withstood the brief 2001 and the persistent 2007 recessions? The findings point to consumption (spending) over stability (revenue minus expense) for the recession of 2007, particularly in 2008 and 2009.
Hassaan Tariq, Faisal Shahzad, Asim Anwar and Ijaz Ur Rehman
This study investigates the impact of insider-ownership of publicly traded firms on their performance, cost of debt (COD) and cost of equity. We use a sample of 104 non-finance…
Abstract
This study investigates the impact of insider-ownership of publicly traded firms on their performance, cost of debt (COD) and cost of equity. We use a sample of 104 non-finance listed companies of Pakistan for the period from 2006 to 2016. Our study is conducted in Pakistan as a developing country in which insider-ownership is dominant, and a weak external corporate governance mechanism increases the payoffs from insider-ownership. We use feasible generalized least square (FGLS) regression methods to examine these hypotheses. Based on agency theory, we find that insider-ownership enhances firm performance. Furthermore, our results show that insider-ownership reduced the COD and equity. Higher ownership decreases the opportunistic behavior of insiders. It also reduces the creditor’s perception of the likelihood of default on loan payments and reduces agency issues among shareholders. The insider will invest in positive NPV projects which will help maximize shareholders’ wealth and minimize the COD. Similarly, the relationship between insider-ownership and cost of equity is significant but negative. Supporting the convergence of interest increase in ownership helps in aligning the goals of managers and stakeholders whereby the insider will focus on value creation by minimizing equity cost.