Physics-aware macromodels for MEMS switches

Author(s):  
Aurel-Sorin Lup ◽  
Gabriela Ciuprina ◽  
Daniel Ioan ◽  
Anton Duca ◽  
Alexandra Nicoloiu ◽  
...  

Purpose The purpose of this paper is to propose a physics-aware algorithm to obtain radio frequency (RF)-reduced models of micro-electromechanical systems (MEMS) switches and show how, together with multiphysics macromodels, they can be realized as circuits that include both lumped and distributed parameters. Design/methodology/approach The macromodels are extracted with a robust procedure from the solution of Maxwell’s equations with electromagnetic circuit element (ECE) boundary conditions. The reduced model is extracted from the simulations of three electromagnetic field problems, in full-wave regime, that correspond to three configurations: signal lines alone, switch in the up and down positions. Findings The technique is exemplified for shunt switches, but it can be extended for lateral switches. Moreover, the algorithm is able take frequency dependence into account both for the signal lines and for the switch model. For the later, the order of the model is increased until a specified accuracy is achieved. Originality/value The use of ECE as boundary conditions for the RF simulation of MEMS switches has the advantage that the definition of ports is unambiguous and robust as the ports are clearly defined. The extraction approach has the advantage that the simplified model keeps the basic phenomena, i.e. the propagation of the signal along the lines. As the macromodel is realized with a netlist that uses transmission lines models, the lines’ extension is natural. The frequency dependence can be included in the model, if needed.

2019 ◽  
Vol 46 (10) ◽  
pp. 1234-1246
Author(s):  
Lambert K. Engelbrecht ◽  
Abigail Ornellas

Purpose Within a neoliberal environment, financial vulnerability of households has become an increasing challenge and there is a requirement of financial literacy education, a necessary activity to facilitate sustainable development and well-being. However, this is seldom a mainstream discourse in social work deliberations. The paper aims to discuss these issues. Design/methodology/approach First, introducing the neoliberal impact on financial well-being and capability for vulnerable households, the authors’ postulation is substantiated on a seven-point argument. The contexts of financially vulnerable households are sketched. Second, a conceptualisation of financial literacy is offered, and third, perspectives on and approaches to financial literacy as a fundamental capability are presented. This is followed by a theoretical foundation of community education as a practice model in social work to develop financial capabilities. In the fifth place, prevailing practices of Financial Capabilities Development (FCD) programmes are offered. Subsequently, the implications of a neoliberal environment for social work practice are examined. Findings The revised global definition of social work encourages the profession to understand and address the structural causes of social problems through collective interventions. As a response, it is argued that community education towards FCD of vulnerable households within a neoliberal environment should be an essential discourse in social development. Originality/value The authors reflect on the significance of FCD, highlighting its contribution towards human security and sustainable development. Although this paper draws on Southern African contexts, the discourse finds resonance in other contexts across the world.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1388
Author(s):  
Daniele Oboe ◽  
Luca Colombo ◽  
Claudio Sbarufatti ◽  
Marco Giglio

The inverse Finite Element Method (iFEM) is receiving more attention for shape sensing due to its independence from the material properties and the external load. However, a proper definition of the model geometry with its boundary conditions is required, together with the acquisition of the structure’s strain field with optimized sensor networks. The iFEM model definition is not trivial in the case of complex structures, in particular, if sensors are not applied on the whole structure allowing just a partial definition of the input strain field. To overcome this issue, this research proposes a simplified iFEM model in which the geometrical complexity is reduced and boundary conditions are tuned with the superimposition of the effects to behave as the real structure. The procedure is assessed for a complex aeronautical structure, where the reference displacement field is first computed in a numerical framework with input strains coming from a direct finite element analysis, confirming the effectiveness of the iFEM based on a simplified geometry. Finally, the model is fed with experimentally acquired strain measurements and the performance of the method is assessed in presence of a high level of uncertainty.


2015 ◽  
Vol 7 (3-4) ◽  
pp. 369-377 ◽  
Author(s):  
Alex Pacini ◽  
Alessandra Costanzo ◽  
Diego Masotti

An increasing interest is arising in developing miniaturized antennas in the microwave range. However, even when the adopted antennas dimensions are small compared with the wavelength, radiation performances have to be preserved to keep the system-operating conditions. For this purpose, magneto-dielectric materials are currently exploited as promising substrates, which allows us to reduce antenna dimensions by exploiting both relative permittivity and permeability. In this paper, we address generic antennas in resonant conditions and we develop a general theoretical approach, not based on simplified equivalent models, to establish topologies most suitable for exploiting high permeability and/or high-permittivity substrates, for miniaturization purposes. A novel definition of the region pertaining to the antenna near-field and of the associated field strength is proposed. It is then showed that radiation efficiency and bandwidth can be preserved only by a selected combinations of antenna topologies and substrate characteristics. Indeed, by the proposed independent approach, we confirm that non-dispersive magneto-dielectric materials with relative permeability greater than unit, can be efficiently adopted only by antennas that are mainly represented by equivalent magnetic sources. Conversely, if equivalent electric sources are involved, the antenna performances are significantly degraded. The theoretical results are validated by full-wave numerical simulations of reference topologies.


2020 ◽  
Vol 34 (4) ◽  
pp. 499-511 ◽  
Author(s):  
Jessica L. Pallant ◽  
Sean Sands ◽  
Ingo Oswald Karpen

Purpose Increasingly, customers are demanding products that fit their individual needs. Many firms respond by cultivating product individualization via mass customization, often integrating this capability via interactive platforms that connect them with customers. Despite such customization, research to date has lacked cohesion, often taking the organizational, rather than customer, view. The purpose of this paper is to provide inconclusive theorizing in regard to customization from the consumers’ perspective. Design/methodology/approach The review and synthesis of the literature revealed that co-configuration is an underexplored domain of mass customization. Consequently, an initial conceptualization of co-configuration is developed and compared with current customization strategies. Specifically, the definition and boundary conditions of co-configuration are compared with three domains of mass customization, namely, co-production, co-construction and co-design. This led to the development of research priority areas to establish an agenda for future research on mass customization and its role in customer’ firm relationships. Findings This paper provides the delineation of four distinct consumer customization strategies, conceptualized in a matrix, and proposes separate customer journey visualizations. In advancing the theoretical understanding by means of a unifying typology, this paper identifies three existing Cs of mass customization (co-production, co-construction and co-design) and focuses specifically on a fourth (co-configuration), identified as an understudied mass customization strategy. Originality/value This paper extends the previous conceptualizations of mass customization comprising co-production, co-design and co-construction. The proposed typology establishes a foundation for four research priority areas that can improve both academic rigor and practical application.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Patrícia Moura e Sá ◽  
Catarina Frade ◽  
Fernanda Jesus ◽  
Mónica Lopes ◽  
Teresa Maneca Lima ◽  
...  

PurposeWicked problems require collaborative innovation approaches. Understanding the problem from the users' perspective is essential. Based on a complex and ill-defined case, the purpose of the current paper is to identify some critical success factors in defining the “right problem” to be addressed.Design/methodology/approachAn empirical research study was carried out in a low-density municipality (case study). Extensive data were collected from official databases, individual semi-structured interviews and a focus group involving citizens, local authorities, civil servants and other relevant stakeholders.FindingsAs defined by the central government, the problem to be addressed by the research team was to identify which justice services should be made available locally to a small- and low-density community. The problem was initially formulated using top-down reasoning. In-depth contact with citizens and key local players revealed that the lack of justice services was not “the issue” for that community. Mobility constraints and the shortage of economic opportunities had a considerable impact on the lack of demand for justice services. By using a bottom-up perspective, it was possible to reframe the problem to be addressed and suggest a new concept to be tested at later stages.Social implicationsThe approach followed called attention to the importance of listening to citizens and local organisations with a profound knowledge of the territory to effectively identify and circumscribe a local problem in the justice field.Originality/valueThe paper highlights the limitations of traditional rational problem-solving approaches and contributes to expanding the voice-of-the-customer principle showing how it can lead to a substantially new definition of the problem to be addressed.


Author(s):  
Tirivanhu Chinyoka ◽  
Daniel Oluwole Makinde

Purpose – The purpose of this paper is to examine the unsteady pressure-driven flow of a reactive third-grade non-Newtonian fluid in a channel filled with a porous medium. The flow is subjected to buoyancy, suction/injection asymmetrical and convective boundary conditions. Design/methodology/approach – The authors assume that exothermic chemical reactions take place within the flow system and that the asymmetric convective heat exchange with the ambient at the surfaces follow Newton’s law of cooling. The authors also assume unidirectional suction injection flow of uniform strength across the channel. The flow system is modeled via coupled non-linear partial differential equations derived from conservation laws of physics. The flow velocity and temperature are obtained by solving the governing equations numerically using semi-implicit finite difference methods. Findings – The authors present the results graphically and draw qualitative and quantitative observations and conclusions with respect to various parameters embedded in the problem. In particular the authors make observations regarding the effects of bouyancy, convective boundary conditions, suction/injection, non-Newtonian character and reaction strength on the flow velocity, temperature, wall shear stress and wall heat transfer. Originality/value – The combined fluid dynamical, porous media and heat transfer effects investigated in this paper have to the authors’ knowledge not been studied. Such fluid dynamical problems find important application in petroleum recovery.


2016 ◽  
Vol 10 (4) ◽  
pp. 268-287 ◽  
Author(s):  
Victor Barger ◽  
James W. Peltier ◽  
Don E. Schultz

Purpose In “Social media’s slippery slope: challenges, opportunities and future research directions”, Schultz and Peltier (2013) asked “whether or how social media can be used to leverage consumer engagement into highly profitable relationships for both parties”. The purpose of this article is to continue this discussion by reviewing recent literature on consumer engagement and proposing a framework for future research. Design/methodology/approach The paper reviews the marketing literature on social media, paying particular attention to consumer engagement, which was identified as a primary area of concern in Schultz and Peltier (2013). Findings A significant amount of research has been conducted on consumer engagement since 2010. Lack of consensus on the definition of the construct has led to fragmentation in the discipline, however. As a result, research related to consumer engagement is often not identified as such, making it difficult for academics and practitioners to stay abreast of developments in this area. Originality/value This critical review provides marketing academics and practitioners insights into the antecedents and consequences of consumer engagement and offers a conceptual framework for future research.


2016 ◽  
Vol 26 (5) ◽  
pp. 1134-1157 ◽  
Author(s):  
Donghee Shin ◽  
Myunggoon Choi ◽  
Jang Hyun Kim ◽  
Jae-gil Lee

Purpose The purpose of this paper is to examine the effects of interaction techniques (e.g. swiping and tapping) and the range of thumb movement on interactivity, engagement, attitude, and behavioral intention in single-handed interaction with smartphones. Design/methodology/approach A 2×2 between-participant experiment (technological features: swiping and tapping×range of thumb movement: wide and narrow) was conducted to study the effects of interaction techniques and thumb movement ranges. Findings The results showed that the range of thumb movement had significant effects on perceived interactivity, engagement, attitude, and behavioral intention, whereas no effects were observed for interaction techniques. A narrow range of thumb movement had more influence on the interactivity outcomes in comparison to a wide range of thumb movement. Practical implications While the subject of actual and perceived interactivity has been discussed, the issue has not been applied to smartphone. Based on the research results, the mobile industry may come up with a design strategy that balances feature- and perception-based interactivity. Originality/value This study adopted the perspective of the hybrid definition of interactivity, which includes both actual and perceived interactivity. Interactivity effect outcomes mediated by perceived interactivity.


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