Leonardo Valero Pereira, Walter Jesus Paucar Casas, Herbert Martins Gomes, Luis Roberto Centeno Drehmer and Emanuel Moutinho Cesconeto
In this paper, improvements in reducing transmitted accelerations in a full vehicle are obtained by optimizing the gain parameters of an active control in a roughness road…
Abstract
Purpose
In this paper, improvements in reducing transmitted accelerations in a full vehicle are obtained by optimizing the gain parameters of an active control in a roughness road profile.
Design/methodology/approach
For a classically designed linear quadratic regulator (LQR) control, the vibration attenuation performance will depend on weighting matrices Q and R. A methodology is proposed in this work to determine the optimal elements of these matrices by using a genetic algorithm method to get enhanced controller performance. The active control is implemented in an eight degrees of freedom (8-DOF) vehicle suspension model, subjected to a standard ISO road profile. The control performance is compared against a controlled system with few Q and R parameters, an active system without optimized gain matrices, and an optimized passive system.
Findings
The control with 12 optimized parameters for Q and R provided the best vibration attenuation, reducing significantly the Root Mean Square (RMS) accelerations at the driver’s seat and car body.
Research limitations/implications
The research has positive implications in a wide class of active control systems, especially those based on a LQR, which was verified by the multibody dynamic systems tested in the paper.
Practical implications
Better active control gains can be devised to improve performance in vibration attenuation.
Originality/value
The main contribution proposed in this work is the improvement of the Q and R parameters simultaneously, in a full 8-DOF vehicle model, which minimizes the driver’s seat acceleration and, at the same time, guarantees vehicle safety.
Details
Keywords
Roberto Leonardo Rana, Christian Bux and Mariarosaria Lombardi
The research provides a systematic literature review on the environmental sustainability of the globe artichoke [Cynara cardunculus L. var. scolymus (L.) Fiori], in the cultivated…
Abstract
Purpose
The research provides a systematic literature review on the environmental sustainability of the globe artichoke [Cynara cardunculus L. var. scolymus (L.) Fiori], in the cultivated cardoon [Cynara cardunculus L. var. altilis DC.] and in the wild cardoon [Cynara cardunculus L. var. sylvestris (Lamk)] supply chains, to fill in the literature data gaps and to identify new research directions.
Design/methodology/approach
In the light of the PRISMA standard guidelines, the research provides a systematic literature review according to six research strings on Scopus and Web of Science. 45 scientific articles have been selected out of 407 contributions. Data have been synthesized according to a co-word analysis through the VOSviewer software, to provide insights into the structure of the research network, to offer a multidimensional scaling and clustering into research groups and to discuss the results.
Findings
The research identifies five main research trends: (1) biomass-to-bioenergy or biomass-to-biocomposite materials; (2) waste-to-bioenergy or waste-to-bioproducts; (3) crop management to increase yield productivity; (4) environmental impacts assessment; (5) irrigation water management. Besides, the research highlights momentous challenges and adopted strategies to tackle climate change and to reduce natural resources consumption, as well as the nexus between circular economy and environmental impact assessment.
Originality/value
The novelty of this study relies on the fact that it analyses the environmental sustainability of the Cynara cardunculus L. spp. Supply chain in a systematic way, giving the opportunity to identify future research directions regarding the environmental impacts associated with agricultural production and industrial transformation.
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Keywords
Leonardo Marques and Marina Dastre Manzanares
Despite the systemic nature of circular economy (CE), theorisation that draws from a supply network perspective is only incipient. Moreover, the operations and supply chain…
Abstract
Purpose
Despite the systemic nature of circular economy (CE), theorisation that draws from a supply network perspective is only incipient. Moreover, the operations and supply chain management (OSCM) field has engaged in little dialogue with circularity. This study explores social network analysis (SNA) to depict how the shift from linear to circular not only leads to higher rates of resource economy, repair and recycle but also reshapes governance dynamics and network structure of supply networks.
Design/methodology/approach
The study departs from a systematic review of the literature and draws from core concepts in OSCM, CE and SNA to offer theoretical propositions that articulate how social network metrics can depict supply network circularity. The framework is illustrated with examples from fashion and electronics industries.
Findings
Four theoretical propositions enlighten how betweenness centrality, eigenvector centrality and network density can explain the shift from linear to circular supply networks across the three CE strategies of narrowing, slowing and closing.
Originality/value
The combination of biomimicry, CE, the push–pull dichotomy and social network metrics offer a theory-driven framework for supply network circularity.