Search results

Builds on previous research by the authors to establish a mathematical representation of the surface roughness of stereolithography (SL) parts. It is the intention of the research to use this modelling technique as a design tool for defining optimum build orientation and planning post‐process finishing operations. During the development of this model, a number of in‐process attributes inherent in SL were seen to affect surface deviation. Most notably the phenomenon known as “print‐through” on down‐facing planes produces a build orientation envelope of very smooth surfaces. Although capable of providing low roughness over some 50°, print‐through smoothing cannot easily be extended to other angles, hence complementary processes for surface smoothing must be developed. Discusses a number of possible solutions, showing how the generation of a meniscus between layers can prove beneficial in reducing SL surface roughness, hence reducing the need for lengthy manual finishing operations.

The purpose of this paper is to examine whether there is significant evidence that hedge fund managers engage in deceptive manipulation of their reported performance results.

A model of hedge fund performance has been developed using standard regression analysis incorporating dependent lagged variables and an autoregressive process. In addition, the extreme bounds analysis technique has been used to examine the robustness and sensitivity of the explanatory variables. Finally, the conditional influence of the global stock market’s returns on hedge fund performance and the conditional return behavior of the Hedge Fund Index’s performance have been explored.

This paper begins by identifying a model of hedge fund performance using passive index funds that is well specified and robust. Next, the lag structure associated with hedge fund returns has been examined and it has been determined that it seems to take the hedge fund managers two months to integrate the global stock market’s returns into their reported performance; however, the lagged variables were reduced from the final model. The paper continues to explore the smoothing behavior by conditioning the dependent lagged variables on positive and negative returns and find that managers are conservative in their estimates of positive performance events, but, when experiencing a negative result, they seem to attempt to rapidly integrate that effect into the return series. The strength of their integration increases as the magnitude of the negative performance increases. Finally, the performance of returns for both the Hedge Fund Index and the passive indices were examined and no significant differences between the conditional returns were found.

The results of this analysis illustrate that hedge fund performance is not all that different from the performance of passive indices included in this paper, although it does offer investors access to a unique return distribution. From a management perspective, we are reminded that we need to be cautious about hastily arriving at conclusions about something that looks different or feels different from everything else, because, at times, our preconceived notions will cause us to avoid participating in something that may add value to our organizations. From an investment perspective, sometimes having something that looks and behaves differently from everything else, improves our investment experience.

This paper provides a well-specified and robust model of hedge fund performance and uses extreme bounds analysis to test the robustness of this model. This paper also investigates the smoothing behavior of hedge fund performance by segmenting the returns into two cohorts, and it finds that the smoothing behavior is only significant after the hedge funds produce positive performance results, the strength of the relationship between the global stock market and hedge fund performance is more economically significant if the market has generated a negative performance result in the previous period, and that as the previous period’s performance becomes increasingly negative, the strength of the relationship between the Hedge Fund Index and the global stock market increases.

This paper discusses the technical issues associated with the acquisition, placement, and folding of fabric materials with mechatronic devices and machines. Earlier work in this area considered the acquisition of fabrics from a stack of materials. Numerous techniques were evaluated and suggested as a satisfactory way to provide “pick and placement” of such materials for various automated processes. Several end‐effector devices were developed which used “pinching and stretching” and “multiple roller” approach for handling, placing, and smoothing fabrics on a flat surface. Fabric wrinkles were detected using a feedback laser sensor to assist in the placement and positioning of fabrics. Later work focused on the positioning of fabrics that required issues of alignment, placement and folding for a variety of fabric operations. A two‐dimensional process considered precise placement, laying down, and then folding of a fabric material to have matched ends using a robot manipulator using visual feedback sensing. Additionally, three‐dimensional diagonal folding of fabric was considered based on knowledge developed from the two‐dimensional case. Work was also conducted to mathematically model and measure deformations of limp fabrics and how wrinkling influenced the process of fabric smoothing, alignment, and folding. The results of this work showed that different fabric types (lighter versus heavier) have different sensitivities and hysteritic effects with respect to wrinkling, smoothing, alignment, and folding.

Health monitoring of concrete is one of the important tasks in the structural health monitoring. The life of any infrastructure relies on the quality of the concrete. The computer vision-based methods are very useful to identify the structural defects. The identification of minor cracks in the noisy concrete image is complex. The purpose of this paper is to denoise the concrete crack images and also segment the cracks.

The novelty of the proposed work lies on the usage of anisotropic diffusion filter in the noisy concrete images. Initially anisotropic diffusion filter is applied to smoothen the concrete images. Adaptive threshold and gray level-based edge stopping constant are used in the diffusion process. The statistical six sigma-based method is utilized to segment the cracks from smoothened concrete images.

The proposed method is compared with five state-of-the-art-methods with the performance metrics of mean square error, peak signal to noise ratio and mean structural similarity. The experimental results highlight the advantages of the proposed method.

The novelty of the proposed work lies on the usage of anisotropic diffusion filter in the noisy concrete images. This research work gives the scope for structural damage evaluation by the automation techniques.

The purpose of this paper is to make the test of flexible printed circuit (FPC) board be more efficient and accurate.

This paper aims to segment an image through applying the technology of computer pattern recognition.

The results indicate that the automatic detection system of FPC board’s defect has high efficiency and accuracy in accordance with the requirements of detection.

This paper managed image segmentation through applying the technology of computer pattern recognition.

The purpose of this paper is to propose a generic framework based on the colour and the texture features for colour‐textured image segmentation. The framework can be applied to any real‐world applications for appropriate interpretation.

The framework derives the contributions of colour and texture in image segmentation. Local binary pattern and an unsupervised k‐means clustering are used to cluster pixels in the chrominance plane. An unsupervised segmentation method is adopted. A quantitative estimation of colour and texture performance in segmentation is presented. The proposed method is tested using different mosaic and natural images and other image database used in computer vision. The framework is applied to three different applications namely, Irish script on screen images, skin cancer images and sediment profile imagery to demonstrate the robustness of the framework.

The inclusion of colour and texture as distributions of regions provided a good discrimination of the colour and the texture. The results indicate that the incorporation of colour information enhanced the texture analysis techniques and the methodology proved effective and efficient.

The novelty lies in the development of a generic framework using both colour and texture features for image segmentation and the different applications from various fields.

This chapter draws upon research conducted in the United Arab Emirates (UAE) on parents' perspectives of transition in early childhood intervention (ECI) for children with special educational needs and disabilities (SEND). The research followed a sequential exploratory mixed methods design to collect both qualitative and quantitative data. Data were collected from semi-structured interviews with 11 parents of children with different types of SEND, followed by a cross-sectional survey administered to (183) parents. Thematic analysis of interviews revealed that parents perceive the transition process as: “smooth,” “stressful,” and “blurring.” Descriptive and inferential statistical analysis tests of the parents' responses to the cross-sectional survey showed significant differences among parents' perspectives toward transition with respect to parents' gender, education, type of child with SEND, and educational setting; no significant differences were found regarding children's gender. Implications for practice regarding transition from ECI to inclusive education are addressed through a transition framework introduced at the end of this chapter.

Fused deposition modelling (FDM) is the most economical additive manufacturing technique. The purpose of this paper is to describe a detailed review of this technique. Total 211 research papers published during the past 26 years, that is, from the year 1994 to 2019 are critically reviewed. Based on the literature review, research gaps are identified and the scope for future work is discussed.

Literature review in the domain of FDM is categorized into five sections – (i) process parameter optimization, (ii) environmental factors affecting the quality of printed parts, (iii) post-production finishing techniques to improve quality of parts, (iv) numerical simulation of process and (iv) recent advances in FDM. Summary of major research work in FDM is presented in tabular form.

Based on literature review, research gaps are identified and scope of future work in FDM along with roadmap is discussed.

In the present paper, literature related to chemical, electric and magnetic properties of FDM parts made up of various filament feedstock materials is not reviewed.

This is a comprehensive literature review in the domain of FDM focused on identifying the direction for future work to enhance the acceptability of FDM printed parts in industries.

In order to more accurately predict the dynamics of the e-commerce market and increase the comprehensive value of the circular e-commerce industry, proposes to use Grey system theory to analyze the circular economy of the e-commerce market.

Construct a Grey system theory model, analyze the big data of e-commerce and circular economy of the e-commerce market and predict the development potential of China's e-commerce market.

The results show that the Grey system theory model can play an important role in the data analysis of circular economy of the e-commerce market.

Use Grey model to analyze e-commerce data, discover e-commerce market rules and problems and then optimize e-commerce market.