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Methods of Graph Decompositions
Get PDFIn general terms, a graph decomposition is a partition of a graph into parts satisfying some special conditions. Methods of Graph Decompositions discusses some state-of-the-art decomposition methods of graph theory, which are highly instrumental when dealing with a number of fundamental concepts such as unigraphs, isomorphism, reconstruction conjectures, k-dimensional graphs, degree sequences, line graphs and line hypergraphs.The first part of the book explores the algebraic theory of graph decomposition, whose major idea is to define a binary operation that turns the set of graphs or objects derived from graphs into an algebraic semigroup. If an operation and a class of graphs are appropriately chosen, then, just as for integers, each graph has a unique factorization (or canonical decomposition) into a product of prime factors. The unique factorization property makes this type of decomposition especially efficient for problems associated with graph isomorphism, and several such examples are described in the book. Another topic is devoted to Krausz-type decompositions, that is, special coverings of graphs by cliques that are directly associated with representation of graphs as line graphs of hypergraphs. The book discusses various algorithmic and structural results associated with the existence, properties and applications of such decompositions.In particular, it demonstrates how Krausz-type decompositions are directly related to topological dimension, information complexity and self-similarity of graphs, thus allowing to establish links between combinatorics, general topology, information theory and studies of complex systems. The above topics are united by the role played in their development by Professor Regina Tyshkevich, and the book is a tribute to her memory. The book will be ideal for researchers, engineers and specialists, who are interested in fundamental problems of graph theory and proof techniques to tackle them
One-shot domain-adaptive imitation learning via progressive learning applied to robotic pouring
Get PDFTraditional deep learning-based visual imitation learning techniques require a large amount of demonstration data for model training, and the pre-trained models are difficult to adapt to new scenarios. To address these limitations, we propose a unified framework using a novel progressive learning approach comprised of three phases: i) a coarse learning phase for concept representation, ii) a fine learning phase for action generation, and iii) an imaginary learning phase for domain adaptation. Overall, this approach leads to a one-shot domain-adaptive imitation learning framework. We use robotic pouring as an example task to evaluate its effectiveness. Our results show that the method has several advantages over contemporary end-to-end imitation learning approaches, including an improved success rate for task execution and more efficient training for deep imitation learning. In addition, the generalizability to new domains is improved, as demonstrated here with novel backgrounds, target containers, and granule combinations in the experiment. We believe that the proposed method is broadly applicable to various industrial or domestic applications that involve deep imitation learning for robotic manipulation, and where the target scenarios are diverse and human demonstration data is limited. For project video, please check our website:. Note to Practitioners —The motivation of this paper is to develop a progressive learning framework, which can be used for both service and industrial robots to learn from human demonstrations, and then transfer the learned skill to different scenarios with ease. We use the robotic pouring task as an example to demonstrate the effectiveness of our proposed method, since pouring is an essential skill for service robots to assist humans’ daily lives, and can benefit robot automation in wet-lab industries. The aim of this research is to enable robots to obtain visuomotor skills (such as the pouring skill), and accomplish the tasks with a high success rate using our proposed progressive learning method. We conducted experiments to show that the proposed method has good performance, high data efficiency and evident generalizability. This is significant for intelligent robots working in various practical applications
“It’s important to think of Pepper as a teaching aid or resource external to the classroom”: A social robot in a school for autistic children
Get PDFFor a period of 3 weeks in June 2021, we embedded a social robot (Softbank Pepper) in a Special Educational Needs (SEN) school for autistic children. The robot’s behaviours and integration into the school were co-designed with the children and teachers, with a focus on improving the well-being of the pupils. Using a mix-method approach, we studied the robot’s adoption over the course of the study, and the impact of the robot’s presence on the children well-being and the school ecosystem. We found that the robot successfully integrated within the school; it fostered and maintained a steady level of interactions (330 interactions, 16h of continuous use over 3weeks) with a small yet meaningful group of children with a positive impact on their well-being; and it led to a nuanced conversation with the students and school staff about the role and impact of such a social technology in a SEN school
Names in adoption law and policy: Representations of family, rights and identities
No full textNames have heightened importance in adoption, affecting the identities of individuals who are adopted and adoptive family making. In this article, we use critical discourse analysis to gauge how names, and especially children’s forenames, are addressed in the specificities of legal and policy texts governing and guiding the milieu of people affected by adoption in England. We argue that the inclusions, omissions and opacity of content on names we uncover are outcomes of underlying representations of ‘family’ within the texts, whereby ‘family surnaming’ is constructed as the preeminent naming issue in adoption, above children’s forename-based identity rights. Our focus on names in adoption advances sociological understandings of the power of names in representing family relationships and individual identities, and of how official discourses of law and policy can privilege some types of relationships over others, and the rights of some family members over others
Mechanical characterisation of adobe samples from the state of Morelos, Mexico
Get PDFProperties of adobe are highly dependent on the local soil composition and can vary significantly depending on fabrication techniques, configurations and state of conservation. The effect of the earthquakes that occurred in 2017 in Mexico relaunched discussion regarding the adequacy and safety of adobe-based constructions – a debate that involves many economic, cultural and social facets related to vernacular expressions and ways of life, long-term sustainability and risk management. In an effort to contribute to this, this paper includes and discusses a series of experiments carried out in typologically representative adobe constructions in the municipality of Tepoztlán (state of Morelos, Mexico). A campaign of ultrasonic pulse velocity tests was conducted on 13 historical buildings with the objective of assessing the variability of the adobe material present in those buildings. Some adobe units were then collected and tested in a laboratory to assess their compressive strength and stress/strain behaviour. From these two sets of experiments, it was possible to obtain valuable insights into the mechanical properties of the adobe that constitutes the characteristic housing typology in the region
Examining the role of television programmes in legitimising inherited wealth and privilege for the super-rich in a society that values meritocracy
No full textRecent years have seen the proliferation of television broadcasts that focus on the lavish lifestyles and consumption of “rich kids.” However, flaunting inherited wealth is an accountable activity within UK society that claims to be based on meritocratic values. Whilst wealthy individuals are a source of public spectatorship, they are also attributed with contributing to economic inequality and inhibiting social mobility. This study draws on social psychology to examine media representations of wealthy heirs accounting for their wealth in popular programmes about the “super rich.” Forty-one and a half hours of non-subscription UK television data from 2016 that included the term “super-rich” was analysed. Drawing on Discursive Social Psychology, heirs were found to be managing an ideological dilemma of accounting for their inherited privilege while in a (supposedly) meritocratic environment. Heirs use four interpretative repertoires to negotiate their unmeritocratic position: (1) having a fair go, (2) unintentional privilege, (3) constructing wealth as “family money” and (4) sharing wealth with loved ones. These interpretative repertoires downplay privilege by redefining ownership, highlight any work they do, construct them as aspirational and present them as lacking agency. The presentation of heirs in entertainment documentaries maintains the illusion of meritocratic conditions
Investigation of energy absorption performances of a 3D printed fiber-reinforced bio-inspired cellular structure under in-plane compression loading
Get PDFThis article proposes glass-fiber-reinforced bone-inspired cellular structures to enhance energy absorption capability. The elastic modulus of the bone-inspired unit cell is obtained analytically based on the energy method and then employed in Particle Swarm Optimization algorithm to get optimized cellular structures. In the optimized cellular structure, the stiffness is optimized and the energy absorption capacity is investigated. A Fused Filament Fabrication 3D printing process is used to fabricate the cellular structures with continuous glass fiber-reinforced polylactic acid (PLA). In-plane compression tests are performed to investigate the mechanical performance of cellular structures. Finite Element Modeling (FEM) is conducted to analyzed the mechanical performance of the structures. In FEM, the failure criterion is determined using the maximum stress and VUSDFLD subroutine, and the damage growth is modeled by decreasing the mechanical properties. A good agreement between numerical and experimental results was observed. Results demonstrated that the energy absorption in glass-fiber-reinforced PLA is ∼250% higher than in the un-reinforced structure. The optimized cellular structure exhibits a stable prolonged plateau stress region and very high specific energy absorption parameters
Identifying the impacts of land-use spatial patterns on street-network accessibility using geospatial methods
Get PDFWhile the land use-street network nexus is well acknowledged, evidence for the one-way impacts of land-use patterns on street accessibility is still inadequate. The measurements of land-use patterns and street accessibility lack systematic knowledge. Their empirical correlations also lack geographical variability, constraining site-specific land-use practices. Therefore, this study overcame the aforementioned limitations by examining the two-level spatial models to formulate accessibility-oriented land plans, using a well-developed Chinese city as an example. Firstly, two landscape metrics—Euclidean Nearest-Neighbor Distance (ENN) and Similarity Index (SIMI)—were used to quantify the intra- and inter-land-use configurations, respectively. Both city-level and local accessibility were measured using spatial design network analysis. Performing both ordinary least squares (OLS) and geographically weighted regression (GWR) models, results identified the statistically significant effects of inter-land-use patterns on two-level street accessibility. An exception was that land-use configurations within residential and industrial regions were irrelevant to street accessibility. We also found GWR was a better-fitting model than OLS when estimating locally-varied accessibility, suggesting hierarchical multiscale land-use planning. Overall, locally heterogeneous evidence in this study can substantialize land use-street network interactions and support the decision-making and implementation of place-specific accessibility-oriented land use
Book Review: Amy E. Guptill, Denise A. Copelton and Betsy Lucal - Food and Society: Principles and Paradoxes (3rd Edn)
Get PDFFood is a significant driver, and indicator, of cultural understandings. The food systems in which food is produced informs the way it is consumed – and consumption is a key cultural communicator. Consider regional differences in food choice which indicate ideas of sameness or difference, perceptions of quality and cost which demarcate classed groups, or dietary choices which inform gendered food intake. Food & Society begins from the understanding that food’s biological and economic materiality always relate to the social; lifestyles, divisions, and notions of togetherness
Dividends, investment and pension contributions
Get PDFWe study the determinants of pension contributions for UK listed companies to better understand how the contributions decision is placed within the wider operational and strategic framework of the company. We model the potential displacement effect of discretionary pension deficit contributions in relation to corporate investment and dividends and find a significant displacement effect in relation to both which is further strengthened for dividends during periods of poor firm performance and financial constraints. Our results imply that the firms dividend payout and investment policies significantly influence its propensity to make extra pension contributions