Exploration through drawings in the conceptual stages of product design

This paper argues that sequences of exploratory drawings - constructed by designer's movements and decisions - trace systematic and logical paths from ideas to designs. This argument has three parts. First, sequences of exploratory sketches produced by product designers, against the same task specification, are analyzed in terms of the cognitive categories of reinterpretation, emergence and abstraction. Second, a computational model is outlined for the process of exploration through drawing and third the model is applied to elucidate the logic in the sequences of exploratory sketches examined earlier

Orientation-Constrained Rectangular Layouts

We construct partitions of rectangles into smaller rectangles from an input consisting of a planar dual graph of the layout together with restrictions on the orientations of edges and junctions of the layout. Such an orientation-constrained layout, if it exists, may be constructed in polynomial time, and all orientation-constrained layouts may be listed in polynomial time per layout.Comment: To appear at Algorithms and Data Structures Symposium, Banff, Canada, August 2009. 12 pages, 5 figure

3D imaging of cell interactions with electrospun PLGA nanofiber membranes for bone regeneration

We acknowledge funding from the QMUL Pump-Priming Research Funding for Cross-Faculty Initiatives 2011-12 (EPSRC

The necessity of historical inquiry in educational research: the case of Religious Education

publication-status: PublishedThis is an Author's Original Manuscript of an article whose final and definitive form, the Version of Record, has been published in the British Journal of Religious Education, July 2010. Available online at: http://www.tandfonline.com/ or DOI: 10.1080/01416200.2010.498612This article explores the mixed fortunes of historical inquiry as a method in educational studies and exposes evidence for the neglect of this method in religious education research in particular. It argues that historical inquiry, as a counterpart to other research methods, can add depth and range to our understanding of education, including religious education, and can illuminate important longer‐term, broader and philosophical issues. The article also argues that many historical voices have remained silent in the existing historiography of religious education because such historiography is too generalised and too biased towards the development of national policy and curriculum and pedagogical theory. To address this limitation in educational research, this article promotes rigorous historical studies that are more substantially grounded in the appropriate historiographical literature and utilise a wide range of original primary sources. Finally, the article explores a specific example of the way in which a historical approach may be fruitfully applied to a particular contemporary debate concerning the nature and purpose of religious education

Enumerating Architectural Arrangements: Comment on a Recent Paper by Baybars and Eastman

Comments and discussion on the method proposed for generating the graphs for enumerating architectural arrangements by Baybars and Eastman (1980

Setting planned job release times in stochastic assembly systems with resource constraints

This paper considers a stochastic assembly system operating on a make-to-order basis with complex product structure and resource constraints. The problem is to find the optimal planned job release times by minimizing the expected sum of the work-in-progress holding cost, product earliness cost and product tardiness cost. A perturbation analysis algorithm is developed to derive the gradient estimate of the cost function with respect to the job release times. This gradient estimate is shown to be unbiased and may lead to the optimal solution by using a stochastic approximation method. Moreover, a procedure is presented to adjust planned job release times to meet service level constraint for each individual job. Numerical examples, which use manufacturing and assembly data from a capital goods company, are given to demonstrate the results

Stage due date planning for multistage assembly systems

Coordinating due dates of operations throughout all stages of manufacturing and assembly is a problem especially for complex product structures with uncertainties in process times. A recursive procedure is described to estimate distributions of completion times for each operation. Stage due dates are then calculated to meet specified service targets. Compared with plans from existing heuristic methods, there are considerable improvements in meeting service targets and reducing costs. Simulations demonstrate that the method is effective for complex assemblies produced in low volumes by capital goods companies

Reducing the cost of Post Combustion Capture technology for Pulverized Coal Power Plants by flexible operation

Currently the low carbon prices, low Spreads and regulatory uncertainties hampers the business cases for coal-fired power plants with post-combustion capture (PCC) in Europe. Improvement of the business case of coal-fired power plants with post combustion capture requires a different approach in terms of operational dispatch and in terms of investment planning. Both items have been assessed using a comprehensive power plant valuation model developed by TNO. To change the typical base-load production profile of a coal-fired power plant into a more flexible production profile, a Flexible Operating Mechanisms (FOMs) has been developed for PCC. Based on the results of the techno-economic modeling, FOMs improve the business case. Next to this, FOMs present coal fuelled power plants with additional flexibility. This added flexibility could allow coal plants to provide auxiliary services to the grid and remain competitive in relation to cleaner gas-fired plants. The increase of operational flexibility with FOMs created a significant improvement of the NPV value and, therefore, it is justified to look in much more detail how the operational flexibility of a coal-fired power plant with Carbon Capture can be improved. Running a power plant with a 100% capture unit at base load will require significant amount financial support to close the gap. Starting with a smaller capture unit reduce the financial risk and could improve the business case of the coal-fired power plant without PCC from a marginal cost point of view. The main reason for this is the increase of flexibility, by switching on/off the capture unit. Next to this, the decision to invest is always affected by the opportunity costs of making a commitment now, and thereby, giving up the option of waiting for improved market condition. Increasing the size of the capture plant in stages enables the investor to manage those opportunity cost much better.Process and EnergyMechanical, Maritime and Materials Engineerin