Communities in university mathematics

This paper concerns communities of learners and teachers that are formed, develop and interact in university mathematics environments through the theoretical lens of Communities of Practice. From this perspective, learning is described as a process of participation and reification in a community in which individuals belong and form their identity through engagement, imagination and alignment. In addition, when inquiry is considered as a fundamental mode of participation, through critical alignment, the community becomes a Community of Inquiry. We discuss these theoretical underpinnings with examples of their application in research in university mathematics education and, in more detail, in two Research Cases which focus on mathematics students' and teachers' perspectives on proof and on engineering students' conceptual understanding of mathematics. The paper concludes with a critical reflection on the theorising of the role of communities in university level teaching and learning and a consideration of ways forward for future research

Production Costs Calculation Model in Crushing and Screening : Using a technical-economic approach tool for finding the optimal production costs when comparing technical and economical solutions

The mining and quarrying industries represent a highly important sector of the Swedish economy. The mining industry operates globally, whereas the quarrying industry operates on a regional/local basis. Demands for metal and construction aggregates have increased over the last decade, and almost 80 billion tons of solid minerals and rocks are extracted from the earth’s crust each year. Construction aggregates are the largest part of this extraction. Most of the metals in the crust are in mineral form, with one or more elements in chemical compounds. To extract the metals, one must first reduce the rock to fine or very fine particles, so creating the right properties for mineral beneficiation and metal extraction.Construction aggregates are used as ballast in concrete and in asphalt or by itself in road building and other infrastructure, such as dams, protection, filling, and landscaping. Construction aggregate ranges in sizes from large boulders to very fine sand, but normally the construction aggregate sizes are in the range of 1–100 mm. Where the railway aggregates are in the coarser part of this range, the aggregates used for asphalt and concrete in the middle part, and the sand in the finer part. Crushing and screening are among the common size reducers and size sorters in the mining and quarrying industries. The crushers are machines for breaking rocks or other minerals into smaller particles/fragments. The screens are the size-sorting machines for separating coarser particles from finer particles. Technical process simulation and equipment selection for crushing and screening (C&S) plants are well established today for mining and quarrying plants.In this dissertation I develop a product cost calculation model (PCCM) that adds one more dimension to the area of process simulation, providing guidelines for calculating product costs within C&S plants and finding the process alternative with the lowest product cost for a C&S plant process application.The PCCM calculates the product costs using process uptime costs, process downtime costs, salary costs and auxiliary costs. The process uptime and downtime costs include capital costs and dynamic process costs such as wear parts, spares, tools, and power consumption

Towards a Methodology for the Economic Performance Increase of Production Lines using Reinforcement Learning

The increasing number of variants in product portfolios contributes to the challenge of efficient manufacturing on production lines due to the resulting small batch sizes and thus frequent product changes that lower the average overall plant effectiveness. Especially for companies that manufacture at high speed on production lines, such as in the Fast Moving Consumer Good (FMCG) industry, it is a central task of operational management to increase the performance of production lines. Due to the multitude of different adjustment levers at several interdependent machines, the identification of efficient actions and their combination into economic improvement trajectories is challenging. There is a variety of approaches to address this challenge, e.g. simulation-based heuristics. However, these approaches mostly focus on details instead of giving a holistic perspective of the possibilities to improve a production line or are limited in practical application. In other areas of application, reinforcement learning has shown remarkable success in recent years. The principle feasibility of using reinforcement learning in this application context has been demonstrated as well. However, it became apparent that the integration of expert knowledge throughout the improvement process is necessary. For this reason this paper transforms five modules defined from an engineering point of view into the mathematical scheme of a markov decision problem, a default framework for reinforcement learning. This provides the foundation for applying reinforcement learning in combination with expert knowledge from an engineering perspective

Analysis of contexts and conceptual variables for a sustainable approach into systemic model

The research deals with an approximation to systemic design focused on sustainability, analyzing issues affecting the conceptualization of a product-system or service, in the initial stages of the design process, determining from a qualitative perspective on this phase of the project, a set of variables that are articulated both from basic design criteria as well as from sustainability criteria. For it, one resorts to the use of a multiobjective design model, in order to manage data, information and knowledge as well as its networks of relationships. It starts from the consideration of multiple sources of uncertainty that are reduced by a filtering process of the outer system, from an approach proposed for such purposes. Similarly, is raised the highlighting of variables that contribute to complement the emotional aspects, spiritual and scale of values related to users or consumers, as a strategy to assist in the process of providing a new pillar to the triad of sustainability, traditionally supported by environmental, economic and social pillars. For the description of procedures, structures and functions, a case study is presented in which are outlined the intrinsic qualities of a reference system and their interaction networks, starting with the filtering process of the outer system, till the obtaining of the key variables that have greater impact on the definition of formal, functional and ergonomic objectives in the inner subsystems

A comparative investigation on different measures to mitigate metro trains induced vibrations from the aspects of Resource, Propagation path, and Receiver

Preservation of historic buildings is a main challenge in the civil engineering field. One of the main concerns about this subject is to be sure of environmental effects like noise and vibration on monuments. To overcome these problems, a wide range of noise and vibration mitigation measures could be applied. To reach a proper evaluation, in this paper, a detailed assessment is made on the efficiency of various vibration mitigation measures by a series of field tests and sensitivity analysis in Isfahan metro lines close to some vibration-sensitive cultural structures. The sensitivity analysis was performed in possible ranges of vertical stiffness of track superstructure materials. Results showed that vertical track stiffness equal to 5 kn/mm would lead to a 5 db reduction with regarding 4 millimeters limit of rail deflection

The Colour of Heating was Red: An overview of historical and policy narratives of domestic heating in Sweden, 1940 - present : JustHeat Strand II Report

This report has been written within the project Looking Back to Move Forward: a Social and Cultural History of Heating (JustHeat). The aim of the project is to unpack previous heating transitions at the home front since 1940 in order to enable more just and inclusive heating transitions in the future. The background is the notion that home heating transitions are deeply personal in the sense that they affect daily routines, division of labour between family members, and how we use our homes and energy alike. While there is much to be learned from intended as well as unintended effects of previous transitions, little effort has been put into understanding the lived experiences of technological changes in home heating, despite the uneven yet deep impacts they have had in society. This project will fill this gap by using oral histories to collect individual and collective experiences of home heating transitions that can complement and nuance dominating transition narratives.As a starting point, this report aims to tell the history of home heating in Sweden as it has been documented and told in policymaking and in the public debate. This will primarily be done by reviewing formative political documents and newspaper articles. In so doing, current transitions in domestic heating can be better understood in light of past transitions, and this report can be used as a formal narrative against which to confirm, complement, and contrast the oral histories. It is by no means a complete review of the events, arguments, and effects of home heating transitions since the 1940’s, but it captures some of the most important changes that – more or less, and for better or for worse – have affected people’s everyday lives

The Distribution of Tone in Shanghainese Monosyllables: An Optimality Theory Approach

This paper aims to create an Optimality Theory ranking of tonal phonology constraints in Shanghai Chinese (Shanghainese) monosyllables. Previous research on tonal phonology in Shanghainese preceded the more recent research on Optimality Theory which may provide new principles to justify the language’s tonal phonology system. I use inputs composed of High (H) and Low (L) tone combinations and 8 constraints, (3 faithfulness and 5 markedness constraints) to motivate the distribution of tones in Shanghainese monosyllable in four environments: KV, GV, KVʔ, GVʔ. The faithfulness constraints include DEP, MAX, and IDENT. The markedness constraints include *KL, *GH, POLARITY, [AGREE]ʔ, and *L/ʔ. The [AGREE]ʔ constraint is undominated which produces solely level tone outputs in the KVʔ and GVʔ environment. Contour tone sequences emerge as winners in the KV and GV environment due to the high ranking of POLARITY. The interaction of tone-specific constraints produces 3 languages that correctly correspond to the tone outputs of Shanghainese monosyllables. Shanghainese is metrically sensitive at both the moraic and the syllable level which enriches its tonal phonology analysis. Further research can be conducted on connected speech at the polysyllabic level

Is body size at birth related to circadian salivary cortisol levels in adulthood? Results from a longitudinal cohort study

<p>Abstract</p> <p>Background</p> <p>The hypothesis of fetal origins of adult disease has during the last decades received interest as an explanation of chronic, e.g. cardiovascular, disease in adulthood stemming from fetal environmental conditions. Early programming and enduring dysregulations of the hypothalamic-pituitary-adrenal (HPA axis), with cortisol as its end product, has been proposed as a possible mechanism by which birth weight influence later health status. However, the fetal origin of the adult cortisol regulation has been insufficiently studied. The present study aims to examine if body size at birth is related to circadian cortisol levels at 43 years.</p> <p>Methods</p> <p>Participants were drawn from a prospective cohort study (n = 752, 74.5%). Salivary cortisol samples were collected at four times during one day at 43 years, and information on birth size was collected retrospectively from delivery records. Information on body mass during adolescence and adulthood and on health behavior, medication and medical conditions at 43 years was collected prospectively by questionnaire and examined as potential confounders. Participants born preterm or < 2500 g were excluded from the main analyses.</p> <p>Results</p> <p>Across the normal spectrum, size at birth (birth weight and ponderal index) was positively related to total (area under the curve, AUC) and bedtime cortisol levels in the total sample. Results were more consistent in men than in women. Descriptively, participants born preterm or < 2500 g also seemed to display elevated evening and total cortisol levels. No associations were found for birth length or for the cortisol awakening response (CAR).</p> <p>Conclusions</p> <p>These results are contradictory to previously reported negative associations between birth weight and adult cortisol levels, and thus tentatively question the assumption that only low birth weight predicts future physiological dysregulations.</p

Publication practices in the Humanities: An in-depth case study of a Swedish Arts and Humanities Faculty 2010-2018

This paper is a case study of research publication practices at the Faculty of Arts and Humanities at Linnaeus University, a young, mid-sized university in the south-east of Sweden. Research output was measured from publications in the local institutional repository following the guidelines of local research policy as defined in university documentation. The data collection comprised 3,316 metadata records of publications self-registered by authors affiliated with the faculty during the period of 2010–2018. A statistical analysis of research output was conducted, focusing on preferred publication types, disciplinary specificity, level of co-authorship, and the language of the publication as registered in the local repository. The analysis focused on two main research questions: 1) how do the local research practices stand in relation to traditional publication patterns in the humanities? 2) how do the observed publication patterns relate to local university policy on publication and research evaluation? The empirical results suggest a limited correlation between publication practices and research incentives from university management, a finding that is corroborated by previous research on the scholarly character of the humanities and university policies. Overall, traditional humanities publication patterns were largely maintained throughout the period under investigation