Analogical reasoning in case-based design

A computer can assist the process of design by analogy by recording past designs. The experience these represent could be much wider than that of designers using the system, who therefore need to identify potential cases of interest. If the computer assists with this lookup, the designers can concentrate on the more interesting aspect of extracting and using the ideas which are found. However, as the knowledge base grows it becomes ever harder to find relevant cases using a keyword indexing scheme without knowing precisely what to look for. Therefore a more flexible searching system is needed.

If a similarity measure can be defined for the features of the designs, then it is possible to match and cluster them. Using a simple measure like co-occurrence of features within a particular case would allow this to happen without human intervention, which is tedious and time- consuming. Any knowledge that is acquired about how features are related to each other will be very shallow: it is not intended as a cognitive model for how humans understand, learn, or retrieve information, but more an attempt to make effective, efficient use of the information available. The question remains of whether such shallow knowledge is sufficient for the task.

A system to retrieve information from a large database is described. It uses co-occurrences to relate keywords to each other, and then extends search queries with similar words. This seems to make relevant material more accessible, providing hope that this retrieval technique can be applied to a broader knowledge base.

Simulation in user-centred design: Helping designers to empathise with atypical users

Time and budget constraints frequently prevent designers from consulting with end-users while assessing the ease of use of the products they create. This has resulted in solutions that are difficult to use by a wide range of users, especially the growing older adult population and people with different types of impairments. To help designers with this problem, capability-loss simulators have been developed with the aim of temporarily representing users who are otherwise difficult to access. This paper questions the reliability of existing tools in providing designers with meaningful information about the users' capabilities. Consequently, a new capability-loss simulation toolkit is presented, followed by its empirical evaluation. The new toolkit proved to be significantly helpful for a group of designers identifying real usability problems with everyday devices. © 2012 Copyright Taylor and Francis Group, LLC.

Two is better than one: Distinct roles for familiarity and recollection in retrieving palimpsest memories

Storing a new pattern in a palimpsest memory system comes at the cost of interfering with the memory traces of previously stored items. Knowing the age of a pattern thus becomes critical for recalling it faithfully. This implies that there should be a tight coupling between estimates of age, as a form of familiarity, and the neural dynamics of recollection, something which current theories omit. Using a normative model of autoassociative memory, we show that a dual memory system, consisting of two interacting modules for familiarity and recollection, has best performance for both recollection and recognition. This finding provides a new window onto actively contentious psychological and neural aspects of recognition memory.

A design strategy in the propulsion system attachment to a submarine hull to minimise radiated noise

Vibration modes of a submerged hull are excited by fluctuating forces generated at the propeller and transmitted to the hull via the propeller-shafting system. The low frequency hull vibrational modes result in significant sound radiation. This work investigates the reduction of the far-field radiated sound pressure by optimising the connection point of the shafting system to the hull. The submarine hull is modelled as a fluid loaded cylindrical hull with truncated conical shells at each end. The propeller-shafting system consists of the propeller, shaft, thrust bearing and foundation, and is modelled in a modular approach using a combination of spring-mass-damper elements and continuous systems (beams, plates, shells). The foundation is attached to the stern side end plate of the hull, which is modelled as a circular plate coupled to an annular plate. By tuning the connection radius of the foundation to the end plate, the maximum radiated noise in a given frequency range can be minimised.

Mired in the meaning: Sustainability in consultancy

This paper explores sustainability as it relates to the services, operations and management of engineering and design (E&D) consulting firms, revealing how sustainability has been adopted by the engineering consulting industry as a key influence on its business. The motivations behind sustainability as a business priority for E&D consulting do not appear to reflect a corporate belief or endorsement of sustainability principles, but rather a reflection of market, employee and government drivers. Through interview-based reporting, the implications of these motivations are the focus of this paper through an exploration of the meaning, understanding and operationalising of sustainability in engineering design, assessment of design and in-firm management and strategy.