Search results

Purpose – In this chapter, we report on the lessons of cross-disciplinary collaborative workshop between sociologists and engineering educators to synthesize what is known about legitimating and disseminating educational reform and to develop a research agenda for what needs to be known in order to spread educational reform and to overcome on-the-ground resistance to change.

Methodology/approach – This chapter is based on a case study of this workshop, describing the “white papers” prepared by participants prior to the workshop and the research agendas that emerged from discussions of them during the workshop and after.

Findings – The workshop resulted in a sophisticated research agenda as well as some modest efforts to create cross-disciplinary links to implement it. However, a one-time workshop did not overcome institutional barriers to this kind of activity.

Research limitations – Since this is a case study of a single collaboration we cannot generalize to all cross-disciplinary collaborations, although it does provide an example of what works to facilitate cross-disciplinary efforts and what obstacles remain.

Practical implications – An advantage to the workshop was the absence of institutional barriers to cross-disciplinary collaboration. Attendees were removed from their institutions, departments, disciplines, and turf battles. However, without increased institutional support for cross-disciplinary efforts, such as this one, the value of the social sciences for diffusing the innovations of science and engineering reform movements may not be realized.

Presents an adaptive slicing procedure for improving the geometric accuracy of layered manufacturing techniques which, unlike previous procedures, uses layers with sloping boundary surfaces that closely match the shape of the required surface. This greatly reduces the stair case effect which is characteristic of layered components with square edges. Considers two measures of error, and outlines a method of predicting these measures for sloping layer surfaces. To cater for different manufacturing requirements, presents a method to produce parts with either an inside or outside tolerance, or a combination of both. Finally, considers some problems associated with surface joins, vertices, and inflection points and proposes some solutions.

TruSurf is a new system for building solid objects from layers with sloping surfaces that closely match the designed surface shape. The advantages of using sloping surfaces over stepped edges are improved surface finish, and decreased build time through the use of thicker layers. TruSurf uses B‐spline surfaces to describe the part, and calculate the sloped path of the layer cutting medium. Describes operation of the system in detail and presents results from the production of some test parts. Discusses some ways for improving accuracy, including using principal directions of minimum surface curvature, and using a curved cutting medium to produce layers.

Cities, like other ecosystems, are changing and evolving at a growing pace. Therefore, innovation has become a critical success factor in the creation of ‘smart cities’. A smart city is one that uses technology as a platform to serve its citizens’ needs and foster innovative processes that enhance their quality of life. In this chapter, the authors present two case studies of urban open innovation processes in, respectively, Haifa in Israel and Bremerhaven in Germany, which demonstrate the engagement of all stakeholders, motivated by passion, altruism and the desire to cooperate. The first case concerns open innovation with the young, and the second open innovation with the elderly. Both case studies demonstrate how passion led to altruism which encouraged citizens to volunteer to contribute and co-create a better future for all the city’s residents by enabling better communication among stakeholders in the context of a complex urban environment.

Presents a method of Max‐Fit biarc curve fitting technique to improve the accuracy of STL files and to reduce the file size for rapid prototyping. STL file has been widely accepted as a de facto standard file format for the rapid prototyping industry. However, STL format is an approximated representation of a true solid/surface model, and a huge amount of STL data is needed to provide sufficient accuracy for rapid prototyping. Presents a Max‐Fit biarc curve fitting technique to reconstruct STL slicing data for rapid prototyping. The Max‐Fit algorithm progresses through the STL slicing intersection points to find the most efficient biarc curve fitting, while improving the accuracy. Our results show that the proposed biarc curve‐fitting technique can significantly improve the accuracy of poorly generated STL files by smoothing the intersection points for rapid prototyping. Therefore, less strict requirements (i.e. loose triangle tolerances) can be used while generating the STL files.

A new surface error calculation method for layered manufacturing processes is proposed in this paper. The developed method is used to generate the layers by adaptively varying the thickness of the layers based on the surface approximation errors. Traditionally, the surface errors are calculated using local approximation techniques. In this paper, the surface approximation errors are calculated more accurately by marching through the surface points and determining the distances between layers and the surface points. Using the calculated distances, the adaptive layers are generated for both traditional two‐dimensional layer and ruled‐layer approximation methods. It has been shown that layered manufacturing (rapid prototyping) processes can achieve better accuracy and efficiency using the proposed surface error calculation and the adaptive ruled layer approximation methods. Computer implementation and illustrative examples are also presented in this paper.

To calculate the volume deviation between a CAD model and built‐up part in 5‐axis laminated object manufacturing employing direct slicing with first‐order approximation.

It is proposed here that the deviation between the CAD model and the built‐up part, which is normally calculated as a linear dimension in specific 2D sections of the CAD model, be treated as a volume (as it actually is), for higher accuracy in subsequent calculations. An algorithm has been developed and implemented for identification and calculation of volume deviation, considering all possibilities.

It has been conclusively shown that volume deviation consideration results in improved feature recognition and less approximation.

Increase in complexity of the CAD model leads to a considerable increase in the volume deviation computation time. Future research in this area would focus on optimization and calculation of the slice heights based on volume deviation.

Calculation of volume deviation would help eliminate the loss of intricate features in a complex surface and thus improve feature recognition. Slice height calculations based on volume deviation would reduce the deviation between the actual model and the built‐up part.

A new method has been developed for the calculation of volume deviation that could be implemented in the rapid prototyping software packages so as to build prototypes with higher accuracy.

In recent days, rapid machining through digital prototyping has been popular for its applicability in a wide range of complex and useful parts. Rapid construction of prototypes from point cloud data based on section plane method is available, which is an approximate method. Discusses some suitable methodology for conversion of point cloud data to a physical prototype where data acquisition is through a mechanical touch trigger probing process using CNC milling machine. The process is quite useful for reverse engineering of complex sculptured parts. A concept called tangent plane method is adopted for the generation of 3D geometry on point cloud data of sculptured parts with due emphasis on probe radius compensation after data capture and tool radius compensation during tool‐path generation. Computer simulated results are presented, based on real‐world point cloud data.

In adaptive slicing, the number of layers is drastically reduced by using sloping layer walls. For both vertical (2.5D slices) and sloping (ruled slices) outer walls, the strategies for determining slice height generally consider a number of vertical sections along the contour of a slice. Surface deviation error is calculated at these sections and slice height subsequently determined. Instead, a method is proposed which calculates error at every part of the surface. This method approximates the outer wall between two successive contours by a series of taut cubic spline patches. It is proposed that the deviation between such a patch and the actual surface is a better and more exhaustive estimate of surface error. Results show that the predicted number of slices is slightly higher than that predicted by existing methods for sloping layer walls.