Representations and evolutionary operators for the scheduling of pump operations in water distribution networks.

Reducing the energy consumption of water distribution networks has never had more significance. The greatest energy savings can be obtained by carefully scheduling the operations of pumps. Schedules can be defined either implicitly, in terms of other elements of the network such as tank levels, or explicitly by specifying the time during which each pump is on/off. The traditional representation of explicit schedules is a string of binary values with each bit representing pump on/off status during a particular time interval. In this paper, we formally define and analyze two new explicit representations based on time-controlled triggers, where the maximum number of pump switches is established beforehand and the schedule may contain less switches than the maximum. In these representations, a pump schedule is divided into a series of integers with each integer representing the number of hours for which a pump is active/inactive. This reduces the number of potential schedules compared to the binary representation, and allows the algorithm to operate on the feasible region of the search space. We propose evolutionary operators for these two new representations. The new representations and their corresponding operations are compared with the two most-used representations in pump scheduling, namely, binary representation and level-controlled triggers. A detailed statistical analysis of the results indicates which parameters have the greatest effect on the performance of evolutionary algorithms. The empirical results show that an evolutionary algorithm using the proposed representations improves over the results obtained by a recent state-of-the-art Hybrid Genetic Algorithm for pump scheduling using level-controlled triggers.

Using an Outdoor Learning Space to Teach Sustainability and Material Processes in HE product Design.

The world is facing environmental changes that are increasingly affecting how we think about manufacturing, the consumption of products and use of resources. Within the HE product design community, thinking and designing sustainability’ has evolved to become a natural part of the curriculum. Paradoxical as the rise in awareness of sustainability increases there is growing concern within HE product design of the loss of workshop facilities and as a consequence a demise in teaching traditional object-making skills and material experimentation. We suggest the loss of workshops and tangible ‘learning by making skills’ also creates a lost opportunity for a rich learning resource to address sustainable thinking, design and manufacture ‘praxis’ within HE design education. Furthermore, as learning spaces are frequently discussed in design research, there seems to be little focus on how the use of an outdoor environment might influence learning outcomes particularly with regard to material teaching and sustainability. This 'case study' of two jewellery workshops, used outdoor learning spaces to explore both its impact on learning outcomes and to introduce some key principles of sustainable working methodologies and practices. Academics and students mainly from Norway and Scotland collaborated on this international research project. Participants made models from disposable packaging materials, which were cast in tin, in the sand on a local beach, using found timber to create a heat source for melting the metal. This approach of using traditional making skills, materials and nature was found to be a relevant contribution to a sustainable discourse.