Multi-Agent System Control and Coordination of an Electrical Network

Multi-Agent Systems (MAS) have the potential to solve Active Network Management (ANM) problems arising from an increase in Distributed Energy Resources (DER). The aim of this research is to integrate a MAS into an electrical network emulation for the purpose of implementing ANM. Initially an overview of agents and MAS and how their characteristics can be used to control and coordinate an electrical network is presented. An electrical network comprising a real-time emulated transmission network connected to a live DER network controlled and coordinated by a MAS is then constructed. The MAS is then used to solve a simple ANM problem: the control and coordination of an electrical network in order to maintain frequency within operational limits. The research concludes that a MAS is successful in solving this ANM problem and also that in the future the developed MAS can be applied to other ANM problems. © 2012 IEEE

Beyond clustering: mean-field dynamics on networks with arbitrary subgraph composition

Clustering is the propensity of nodes that share a common neighbour to be connected. It is ubiquitous in many networks but poses many modelling challenges. Clustering typically manifests itself by a higher than expected frequency of triangles, and this has led to the principle of constructing networks from such building blocks. This approach has been generalised to networks being constructed from a set of more exotic subgraphs. As long as these are fully connected, it is then possible to derive mean-field models that approximate epidemic dynamics well. However, there are virtually no results for non-fully connected subgraphs. In this paper, we provide a general and automated approach to deriving a set of ordinary differential equations, or mean-field model, that describes, to a high degree of accuracy, the expected values of system-level quantities, such as the prevalence of infection. Our approach offers a previously unattainable degree of control over the arrangement of subgraphs and network characteristics such as classical node degree, variance and clustering. The combination of these features makes it possible to generate families of networks with different subgraph compositions while keeping classical network metrics constant. Using our approach, we show that higher-order structure realised either through the introduction of loops of different sizes or by generating networks based on different subgraphs but with identical degree distribution and clustering, leads to non-negligible differences in epidemic dynamics

Evolution of superficial spreading melanoma to resemble desmoplastic melanoma: case report.

Desmoplastic melanoma commonly occurs on the head and neck in a pure form, but occasionally, it occurs in a mixed tumor with another type, usually superficial spreading melanoma (SSM), and rarely as a metastasis from a primary SSM. We report here a primary SSM on the leg of a 32-year-old male which metastasised to lymph nodes, and 10 years later recurred at the primary site initially with mixed features but evolving to resemble a uniformly desmoplastic, deeply invasive melanoma. This unusual case has implications for clinical management and is additionally notable for its reversal in behavior, from metastatic to local infiltrative type, correlating with the change in morphology

Decision for reconstructive interventions of the upper limb in individuals with tetraplegia: the effect of treatment characteristics

Objective: To determine the effect of treatment characteristics on the\ud decision for reconstructive interventions for the upper extremities (UE) in\ud subjects with tetraplegia. - \ud Setting: Seven specialized spinal cord injury centres in the Netherlands. - \ud Method: Treatment characteristics for UE reconstructive interventions were\ud determined. Conjoint analysis (CA) was used to determine the contribution\ud and the relative importance of the treatment characteristics on the decision\ud for therapy. Therefore, a number of different treatment scenarios using these\ud characteristics were established. Different pairs of scenarios were presented\ud to subjects who were asked to choose the preferred scenario of each set. - \ud Results: forty nine subjects with tetraplegia with a stable C5, C6 or C7\ud lesion were selected. All treatment characteristics significantly influenced\ud the choice for treatment. Relative importance of treatment characteristics\ud were: intervention type (surgery or surgery with FES implant) 13%, number\ud of operations 15%, in patient rehabilitation period 22%, ambulant\ud rehabilitation period 9%, complication rate 15%, improvement of elbow\ud function 10%, improvement of hand function 15%. In deciding for therapy\ud 40% of the subjects focused on one characteristic. - \ud Conclusion: CA is applicable in Spinal Cord Injury medicine to study the\ud effect of health outcomes and non-health outcomes on the decision for\ud treatment. Non-health outcomes which relate to the intensity of treatment\ud are equally important or even more important than functional outcome in the\ud decision for reconstructive UE surgery in subjects with tetraplegia

Microscopic and Macroscopic Properties of Carbohydrate Solutions in the Ionic Liquid 1-Ethyl-3-methyl-imidazolium Acetate

Solutions of glucose, cellobiose, and microcrystalline cellulose in the ionic liquid 1-ethyl-3-methyl-imidazolium acetate ([C2mim][OAc]) have been examined using low-field (20 MHz) NMR relaxometry and rheology. The spin–lattice (T1) and spin–spin (T2) relaxation times have been determined from 30 to 70 °C inclusive, for a range of concentrations (0–15 wt %) of each carbohydrate in [C2mim][OAc]. The zero shear rate viscosities for the same samples across the same temperature range were studied. The viscosity, NMR relaxometry, and previously published diffusion data were all analyzed together through the Debye–Stokes–Einstein equations. Microscopically, these systems behave as an “ideal mixture” of free ions and ions associated with the carbohydrate molecules. The molar ratio of carbohydrate OH groups to ionic liquid molecules, α, is the key parameter in determining the NMR relaxometry and hence the local microscopic environment of the ions. NMR relaxometry data are found to follow an Arrhenius type behavior, and the difference in rotational activation energy between free and associated ions is determined at 6.2 ± 0.5 kJ/mol

A qualitative study of health professionals’ views on using iPads to facilitate distraction during paediatric burn dressing changes

Introduction: Distraction is a non-pharmacologic pain management technique commonly used to avert a person’s attention from procedural pain and distress during stressful procedures such as treatment after a burn injury. In recent years, computer tablets (such as iPads) have been used within paediatric burns services to facilitate distraction by way of apps, games, cartoons and videos during dressing changes. However, we know very little about health professionals’ experiences of using them in this context.Methods: The current study explored health professionals’ experiences of using iPads to facilitate distraction during paediatric burn dressing changes. Fifteen health professionals from a single paediatric burns unit were interviewed. Thematic analysis revealed two key themes: (1) the iPad is a universal panacea for distraction; and (2) trials and tribulations.Discussion: Participants considered iPads to be potentially useful and effective distraction tools, suitable for use with a wide range of patients with burn injuries including young children, adolescents and young adults. However, issues including health professionals’ understandings of one another’s roles, the challenge of working in a busy burns service, and lack of experience and confidence were identified as possible barriers to their use within routine burn care. Training for staff on the use of iPads as a means of facilitating distraction, development of guidelines and a review of how they are incorporated into routine burn care are recommended