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A Generalized Method for Efficient Global Optimization of Antenna Design
Get PDFEfficiency improvement is of great significance for simulation-driven antenna design optimization methods based on evolutionary algorithms (EAs). The two main efficiency enhancement methods exploit data-driven surrogate models and/or multi-fidelity simulation models to assist EAs. However, optimization methods based on the latter either need ad hoc low-fidelity model setup or have difficulties in handling problems with more than a few design variables, which is a main barrier for industrial applications. To address this issue, a generalized three stage multi-fidelity-simulation-model assisted antenna design optimization framework is proposed in this paper. The main ideas include introduction of a novel data mining stage handling the discrepancy between simulation models of different fidelities, and a surrogate-model-assisted combined global and local search stage for efficient high-fidelity simulation model-based optimization. This framework is then applied to SADEA, which is a state-of-the-art surrogate-model-assisted antenna design optimization method, constructing SADEA-II. Experimental results indicate that SADEA-II successfully handles various discrepancy between simulation models and considerably outperforms SADEA in terms of computational efficiency while ensuring improved design quality
Social care legislation as an act of integration
Get PDFThe purpose of this paper is to investigate health and social care integration in North Wales in a short window of time between the assent of the Social Services and Well-being (Wales) Act 2014 and its implementation in 2016
Real-time model of synchronous reluctance motor drive for laboratory based investigations
Get PDFThe Synchronous Reluctance Motor has received much attention in recent years as a very promising solution for electric drives in the near future. This paper presents a real-time model of the motor to be implemented into a software environment used for DSP control system development including debugging. The model is used in laboratory based investigations in academia in order to analyse the performance of electric drives based on a synchronous reluctance motor
Numerical simulation and analytical models for thin film CdTe layers deposited by an inline AP-metalorganic chemical vapour deposition process
Get PDFThe metalorganic chemical vapour deposition (MOCVD) as an attractive method for depositing CdTe and other group II-VI compound thin films has been widely used for fabrication of optoelectronic devices, including photovoltaic solar cells. The thin film deposition of CdTe layer on a substrate with dimethylcadmium (DMCd) and diisopropyltelluride (DIPTe) as precursors has been investigated both numerically and experimentally using an inline reactor. The present work mainly focuses on two aspects of the inline AP-MOCVD process: (1) effects of key deposition parameters such as the substrate temperature Ts, the deposition profile, the film thickness distribution and material utilisation on the pyrolysis of CdTe using the dynamic mode (moving substrate) in the simulation; (2) optimisation of the process conditions using static mode (stationary substrate). Both two-dimension (2D) and three-dimension (3D) computational fluid dynamics (CFD) modelling simulations were conducted to simulate the deposition process. Two modelling modes were trialled in the present work, one with the 2D simulation and optimisation of process conditions being conducted by adopting the dynamic mode and the other with 3D simulation but adopting the static mode. The use of dynamic mode in the CFD modelling for CdTe thin film MOCVD was found to be more suitable for approximation of the actual deposition process. The predicted thin film growth rates are consistent with those obtained from the deposition experiments
Design and performance study of pattern reconfigurable MIMO antennas for mobile smartphones
Get PDFThis paper presents compact pattern reconfigurable antennas for mobile handsets in MIMO configuration. Each antenna of the MIMO configuration being coupled fed monopole in meandered form is capable of covering several cellular frequency bands in the range of 1.75–2.67 GHz including 4G‐LTE, 2G‐GSM, 3G‐UMTS, and WLAN. The MIMO antennas are printed diagonally at the left and right no‐ground portions on the top layer of the substrate to enhance the isolation performance. The substrate used is FR‐4 with relative permittivity of 4.35 and loss tangent of 0.02. The volume of the substrate is 120 × 65 × 1.6 mm3 with each antenna occupying an area of 26.5 × 14.5 mm2. The pattern reconfigurability is achieved by connecting and disconnecting a 4.5 × 2 mm2 metallic strip using the p‐i‐n diode switch. The antennas are pattern reconfigurable in the frequency range of 1.9–2.1 GHz. The isolation achieved is better than 16 dB over all the frequency bands covered by each antenna. A prototype has been fabricated and tested. The simulated and measured results show a good performance of the MIMO antennas. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:148–156, 201
Psychological type profile of Canadian Baptist youth leaders: Implications for Christian education
Get PDFA recent study of the psychological type profile of Christian youth workers in the UK drew attention to differences between the profiles of youth workers and clergy, and highlighted distinctive strengths and weaknesses that may be experienced by youth workers in Christian ministry. The present study, employing the Francis Psychological Type Scales among Canadian Baptist youth leaders (150 men, 186 women), cautions against generalizing on the basis of findings from the UK study. Among the Canadian Baptist youth leaders, compared with the UK Christian youth workers, there were higher proportions of introverts, sensing types, thinking types and judging types
The Sound of the Smell (and taste) of my Shoes too: Mapping the Senses using Emotion as a Medium
Get PDFThis work discusses basic human senses: sight; sound; touch; taste; and smell; and the way in which it may be possible to compensate for lack of one, or more, of these by explicitly representing stimuli using the remaining senses. There may be many situations or scenarios where not all five of these base senses are being stimulated, either because of an optional restriction or deficit or because of a physical or sensory impairment such as loss of sight or touch sensation. Related to this there are other scenarios where sensory matching problems may occur. For example: a user immersed in a virtual environment may have a sense of smell from the real world that is unconnected to the virtual world. In particular, this paper is concerned with how sound can be used to compensate for the lack of other sensory stimulation and vice-versa. As a link is well established already between the visual, touch, and auditory systems, more attention is given to taste and smell, and their relationship with sound. This work presents theoretical concepts, largely oriented around mapping other sensory qualities to sound, based upon existing work in the literature and emerging technologies, to discuss where particular gaps currently exist, how emotion could be a medium to cross-modal representations, and how these might be addressed in future research. It is postulated that descriptive qualities, such as timbre or emotion, are currently the most viable routes for further study and that this may be later integrated with the wider body of research into sensory augmentation
Molecular characteristics, association and interfacial properties of Gum Arabic harvested from both Acacia Senegal and Acacia seyal
Get PDFThe molecular composition of Acacia senegal and Acacia seyal gum exudate samples were studied using transmission electron microscopy. The molecules observed in both samples were found to have diameters of either ~ 20μm, ~60 μm or ~ 10μm. These most likely represent the arabinogalactan (AG), arabinogalactan-protein (AGP) and glycoprotein (GP) molecules present in Acacia gum exudates. Micrographs obtained for gum solutions that had been left to stand for up to 5 days indicated that molecular aggregation had occurred, this was particularly evident for the Acacia senegal sample. This aggregation process was attributed to intermolecular electrostatic interactions. The adsorbed layer thickness of the gums adsorbed onto polystyrene latex particles was determined using dynamic light scattering. For the Acacia senegal gum sample, it was found that the adsorbed layer thickness increased over time and after 14 days had a value of 61nm. These findings are indicative of multilayer adsorption, through intermolecular electrostatic interaction. For the Acacia seyal gum sample the adsorbed layer thickness was only ~3nm and did not increase over time. Transmission electron microscopy revealed the presence of a distinct, thick adsorbed layer for the Acacia senegal gum and the presence of a much thinner, more diffuse layer for the Acacia seyal gum sample. Emulsification studies showed that the Acacia Senegal gum was more effective at stabilising limonene oil-in-water emulsions than the Acacia seyal sample and that this was because markedly more Acacia senegal gum adsorbed at the oil-water interface compared to the Acacia seyal gum exudate
Promoting well-being: Crisis, loss and alcohol
Get PDFWell-being is a concept which can connect together a number of important ideas that have a strong resonance for professional education and practice across the human services. This can critically include considerations of illness, crisis, and loss. Such acute moments in individuals’ lives can be examined through their precipitating events, coping mechanisms, and responses. This article explores some of the dimensions of well-being and how they facilitate a greater understanding of illness, crisis, and loss. These deliberations are then exemplified through a focus on alcohol and other drug use
The psychometric properties of the Sahin-Francis Scale of Attitude toward Islam Revised among Sunni students in Malaysia
Get PDFThis study examines the psychometric properties of a revised form of the Sahin-Francis Scale of Attitude towards Islam comprising only positive valence items. Data provided by 189 Sunni students in Malaysia (41 males and 148 females) support the internal consistency reliability and construct validity of this instrument and commend it for application in further studies