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Fuzzy association rule mining (FARM) is a mainstream method to discover hidden patterns and association rules in quantitative data. It is essential to improve performance metrics, including quantity performance (e.g., the number of rules, the number of frequent itemsets) and quality performance (e.g., fuzzy support and confidence). The current approaches inadequately support optimisation of both quantity and quality performance. We propose a multi-objective optimisation algorithm for FARM (MOOFARM), where quantity and quality performance metrics are improved and validated simultaneously. The experimental evaluation conducted on a real dataset showcases the outstanding performance of MOOFARM against state-of-the-art works. In particular, at minimum support = 0.1, minimum confidence = 0.7, our MOOFARM increases the quantity performance up to 11 times. The proposed method improves the quality performance up to 71.05%. [ABSTRACT FROM AUTHOR]

This paper presents a new technique for introducing and tuning parallelism for heterogeneous shared-memory systems (comprising a mixture of CPUs and GPUs), using a combination of algorithmic skeletons (such as farms and pipelines), Monte–Carlo tree search for deriving mappings of tasks to available hardware resources, and refactoring tool support for applying the patterns and mappings in an easy and effective way. Using our approach, we demonstrate easily obtainable, significant and scalable speedups on a number of case studies showing speedups of up to 41 over the sequential code on a 24-core machine with one GPU. We also demonstrate that the speedups obtained by mappings derived by the MCTS algorithm are within 5–15% of the best-obtained manual parallelisation. [ABSTRACT FROM AUTHOR]

Fault current limiter (FCL) is a kind of device with current‐dependent impedance that has low impedance in normal state of power system, and high impedance during fault condition. Among all classes of FCLs, the saturated iron‐core FCL (SICFCL) is practically the most favourable one nowadays. In this study, a numerical method for design and cost optimisation of SICFCLs is presented. It uses a set of constraints to ensure the desirable operation of the SICFCL based on its electrical and magnetic characteristics. For numerical calculations and optimisations, GAMS software has been used. Suitability of the method is approved by design, simulation and test of a 3500 VA prototype. Magnetic field distributions are simulated using COMSOL Multiphysics and performance of the designed SICFCL is evaluated in a power system hardware model. Simulation and experimental results show the satisfying agreement with predicted results by the proposed numerical method. [ABSTRACT FROM AUTHOR]

Hybrid electric vehicles (HEVs) provide a promising alternative to conventional engine‐powered vehicles, with less emission and better fuel economy. This study proposes a hierarchical control for a power‐split HEV over a driving cycle, featuring pre‐trip optimisation and en‐route speed adaption. Constraints including vehicle powertrain boundaries, road gradients, and speed limits, are taken into consideration. In the first stage, the HEV operating conditions, including the optimal vehicle SOC, speed profiles, and total driving time, are generated for the entire trip before departure. Based on the pre‐trip results, the second stage adapts the vehicle speed for a short horizon when driving, while taking the safety spacing to the preceding vehicle into consideration, which acts as an indicator of actual traffic conditions and guarantees safe driving. Both optimisations are conducted under the distance domain for realising localisation in the optimal speed profile due to frequent changes in traffic conditions. An estimation of distribution algorithm is used to run the simulation so that the feasibility, robustness, and effectiveness of the proposed hierarchical control can be demonstrated. [ABSTRACT FROM AUTHOR]

Variable reluctance (VR) resolvers have some distinguish features over wounded rotor resolvers that make them suitable for industrial applications. Among different types of VR resolvers, sinusoidal‐rotor resolvers are preferred due to simple structure and high performance under eccentricities. However, their accuracy is affected by inevitable run‐out error. As they work based on sinusoidal variation of coupling area between stator and rotor and under run‐out error the coupling area is impaired. Hence, in this study, a new disk shape configuration is proposed for sinusoidal‐rotor resolver that is robust against run‐out error. Geometrical dimensions are calculated based on optimisations to achieve more accuracy. Three‐dimensional time‐stepping finite‐element method is used to show the preference of the proposed resolver. Finally, prototypes of both conventional and proposed sensors are built and tested. Experimental results verify the success of the proposed structure. [ABSTRACT FROM AUTHOR]

The authors address control system design based on an interval observer for non‐linear switched systems with non‐linear vector functions that are assumed to satisfy Lipschitz conditions. First, the observer gain satisfying a Metzler matrix can be solved by optimisations of linear matrix inequalities (LMIs). Second, an interval observer is designed to estimate the states of non‐linear switched systems with the average dwell time scheme, and sufficient conditions for state estimation are presented in terms of an LMI formulation. Third, based on an interval observer, state feedback matrices are designed to construct an asymptotically stabilising switching controller. Finally, a numerical example is provided to demonstrate the efficiency of the approach. [ABSTRACT FROM AUTHOR]