5,850 research outputs found

    Depth Functions for Partial Orders with a Descriptive Analysis of Machine Learning Algorithms

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    We propose a framework for descriptively analyzing sets of partial orders based on the concept of depth functions. Despite intensive studies of depth functions in linear and metric spaces, there is very little discussion on depth functions for non-standard data types such as partial orders. We introduce an adaptation of the well-known simplicial depth to the set of all partial orders, the union-free generic (ufg) depth. Moreover, we utilize our ufg depth for a comparison of machine learning algorithms based on multidimensional performance measures. Concretely, we analyze the distribution of different classifier performances over a sample of standard benchmark data sets. Our results promisingly demonstrate that our approach differs substantially from existing benchmarking approaches and, therefore, adds a new perspective to the vivid debate on the comparison of classifiers.Comment: Accepted to ISIPTA 2023; Forthcoming in: Proceedings of Machine Learning Researc

    Development of Porous Rubber Pavement for the Canadian Climate

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    Permeable pavement usage in North America has increased over the last decade as a viable stormwater management system. Porous Rubber Pavement (PRP) is a new material in this category which has been currently utilized as a pavement surface material for low-traffic areas and pedestrian walkways. This material consists of recycled crumb rubber aggregates, granite aggregates and polyurethane as a binder and is proportioned to attain a very high percentage of interconnected air voids (up to 45%). As a new pavement material in North America, the properties and performance of PRP are not thoroughly understood for cold climate conditions. This research aimed to understand the properties and performance of PRP and improve its performance as a pavement surface material for the Canadian climate. This objective is achieved through an evaluation of existing sites and mixes, developing new mixes through an experimental design process, and evaluating new mixes in the laboratory facilities. Some of the mixes were selected to apply in the trial section to assess field performance. Finally, recommendations and guidelines are developed for this climatic zone. Through the experimental design, four new mixes were developed using different proportions of stone aggregates, rubber aggregates and polyurethane binder. Also, using the proportion of the Control Mix, four polyurethane binders were used to make four different mixes to determine the different binder effects in PRPs. In the next stage of research, two trial sections were constructed using selected mixes along with the Control Mix. In addition, samples were also prepared from the field mixes to test their properties in the laboratory. Then the field performance of the various mixes was evaluated over a series of months. They were initially tested immediately following construction before fully opening for traffic. Then three weeks after construction and after seven months when the sections had experienced their first winter. Preliminary field investigations showed that with the current commercial mix, the achieved elastic modulus of PRP surfaces ranged between 37 MPa and 33 MPa. Besides, frictional values ranged between 57 BPN and 74 BPN. Higher IRI values were calculated for both sites, ranging between 7.56 m/km to 15.77 m/km. The average infiltration rate for the pavement surface areas was found to be 30836 mm/hr. The mechanical properties and durability of the Control Mix and newly developed mixes were investigated. The tensile and compressive strength of the mixes were found to be higher when the percentages of stone aggregates and binders were increased in the mixes. Additionally, an increase in air voids in the samples reduced the materials' tensile and compressive strength. Concerning the types of binder and sources, the obtained results showed no considerable influence of different types of binder in compressive strength test results, whereas binder sources influenced the tensile strength of the PRP materials. PRP samples with varying compositions retained more than 70% of their tensile strength after conditioning with five freeze-thaw cycles. However, due to the variety of binders used, retained tensile strength for PRP samples varied, and some showed retained tensile strength below 70%. The durability study showed that the granite stones that were used for all the sample preparation were not strong enough to withstand higher abrasion loss. However, PRPs with different compositions showed good rutting resistance, ranging from 0.3mm to 2.8mm in different mixes. Moisture-induced damage, stripping related abrasion was also found to be very small in PRP mixes, ranging from 2.6% to 0.1%. Also, the use of different binders from different sources showed that the B2—aliphatic binder could withstand more rutting than other binders. A Los Angeles abrasion tester tested unconditioned and conditioned samples to determine the materials' ravelling resistance. The result showed that abrasion loss increased in the samples after conditioning with five freeze-thaw cycles. However, it was consistent with the mix types. On the other hand, abrasion loss of samples with different binders occurred differently in the conditioned and unconditioned situations and was inconsistent in the mixes. Subgrade samples were collected from sites A and B during the trial section construction. The bearing capacity of subgrade soil for Site B was found to be higher than that of Site A. Subsequently, the performance of the mixes in the sections was evaluated through a series of field testing. The LWD results showed that the stiffness modulus differed for the same mixes at Site A and Site B. Besides, all the mixes showed higher stiffness in the 2nd field test than the 1st since compaction occurred on the pavement after opening for traffic. Nevertheless, after experiencing their first winter, a reduction in stiffness was observed for all mixes in the 3rd test. The BPT test revealed that a higher frictional value of PRP mixes was associated with a higher percentage of rubber aggregates and a lower percentage of binder in the mixes. At the same time, a reduction in BPN values was observed in the 2nd test than in the 1st since the sections were further compacted and polished after opening for traffic. In addition, the surface ravelling and transported loose particles affected the frictional values in the 3rd test, increasing the BPN numbers. Initial rut depths on Site A for different mixes ranged from -7.0 mm to -8.7mm, and the range was -5.8 mm to -10.7mm for Site B. However, after fully opening for traffic, greater rut depths were observed on each section due to the additional compaction under the wheel paths. The permeability of the PRP sections ranged from 28368 mm/h to 45605 mm/h, which is higher than the highest rainfall rate in Canada (298.8 mm/h). However, most of the sections showed higher permeability in the 2nd test. After the first winter, the permeability of some of the sections was found to be further increased, whereas others were found to be decreased due to the influence of site surroundings. In the 1st and 2nd field tests, no visible surface distress was observed at Site A and Site B. A small amount of surface distress was observed after the first winter (seven months after the construction), which included a slight loss of coarse aggregate, minor ravelling, small cracking, and rutting. Throughout the trial section construction process, it was also observed that by improving the construction methods and making slight modifications during the construction process (like increased compaction), the performance of PRPs could be further enhanced. Finally, a set of recommendations and guidelines were developed for using the PRP in the Canadian climate

    An empirical investigation of the relationship between integration, dynamic capabilities and performance in supply chains

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    This research aimed to develop an empirical understanding of the relationships between integration, dynamic capabilities and performance in the supply chain domain, based on which, two conceptual frameworks were constructed to advance the field. The core motivation for the research was that, at the stage of writing the thesis, the combined relationship between the three concepts had not yet been examined, although their interrelationships have been studied individually. To achieve this aim, deductive and inductive reasoning logics were utilised to guide the qualitative study, which was undertaken via multiple case studies to investigate lines of enquiry that would address the research questions formulated. This is consistent with the author’s philosophical adoption of the ontology of relativism and the epistemology of constructionism, which was considered appropriate to address the research questions. Empirical data and evidence were collected, and various triangulation techniques were employed to ensure their credibility. Some key features of grounded theory coding techniques were drawn upon for data coding and analysis, generating two levels of findings. These revealed that whilst integration and dynamic capabilities were crucial in improving performance, the performance also informed the former. This reflects a cyclical and iterative approach rather than one purely based on linearity. Adopting a holistic approach towards the relationship was key in producing complementary strategies that can deliver sustainable supply chain performance. The research makes theoretical, methodological and practical contributions to the field of supply chain management. The theoretical contribution includes the development of two emerging conceptual frameworks at the micro and macro levels. The former provides greater specificity, as it allows meta-analytic evaluation of the three concepts and their dimensions, providing a detailed insight into their correlations. The latter gives a holistic view of their relationships and how they are connected, reflecting a middle-range theory that bridges theory and practice. The methodological contribution lies in presenting models that address gaps associated with the inconsistent use of terminologies in philosophical assumptions, and lack of rigor in deploying case study research methods. In terms of its practical contribution, this research offers insights that practitioners could adopt to enhance their performance. They can do so without necessarily having to forgo certain desired outcomes using targeted integrative strategies and drawing on their dynamic capabilities

    Machine Learning Meets Mental Training -- A Proof of Concept Applied to Memory Sports

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    This work aims to combine these two fields together by presenting a practical implementation of machine learning to the particular form of mental training that is the art of memory, taken in its competitive version called "Memory Sports". Such a fusion, on the one hand, strives to raise awareness about both realms, while on the other it seeks to encourage research in this mixed field as a way to, ultimately, drive forward the development of this seemingly underestimated sport.Comment: 75 pages, 47 figures, 2 tables, 26 code excerpt

    Systemic Circular Economy Solutions for Fiber Reinforced Composites

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    This open access book provides an overview of the work undertaken within the FiberEUse project, which developed solutions enhancing the profitability of composite recycling and reuse in value-added products, with a cross-sectorial approach. Glass and carbon fiber reinforced polymers, or composites, are increasingly used as structural materials in many manufacturing sectors like transport, constructions and energy due to their better lightweight and corrosion resistance compared to metals. However, composite recycling is still a challenge since no significant added value in the recycling and reprocessing of composites is demonstrated. FiberEUse developed innovative solutions and business models towards sustainable Circular Economy solutions for post-use composite-made products. Three strategies are presented, namely mechanical recycling of short fibers, thermal recycling of long fibers and modular car parts design for sustainable disassembly and remanufacturing. The validation of the FiberEUse approach within eight industrial demonstrators shows the potentials towards new Circular Economy value-chains for composite materials

    A comparative analysis of gender equality law in Europe 2022

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    This report provides a general overview of the ways in which EU gender equality law has been implemented in the domestic laws of the 27 Member States of the European Union, as well as Iceland, Liechtenstein and Norway (the EEA countries), the United Kingdom and five candidate countries (Albania, Montenegro, North Macedonia, Serbia and Turkey). The analysis is based on the country reports written by the gender equality law experts of the European equality law network (EELN). At the same time, the report explains the most important elements of the EU gender equality acquis. The term ‘EU gender equality acquis’ refers to all the relevant EU Treaty and EU Charter of Fundamental Rights provisions, legislation and case law of the CJEU in relation to gender equality

    The Politics of Platformization: Amsterdam Dialogues on Platform Theory

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    What is platformization and why is it a relevant category in the contemporary political landscape? How is it related to cybernetics and the history of computation? This book tries to answer such questions by engaging in multidisciplinary dialogues about the first ten years of the emerging fields of platform studies and platform theory. It deploys a narrative and playful approach that makes use of anecdotes, personal histories, etymologies, and futurable speculations to investigate both the fragmented genealogy that led to platformization and the organizational and economic trends that guide nowadays platform sociotechnical imaginaries

    Handbook Transdisciplinary Learning

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    What is transdisciplinarity - and what are its methods? How does a living lab work? What is the purpose of citizen science, student-organized teaching and cooperative education? This handbook unpacks key terms and concepts to describe the range of transdisciplinary learning in the context of academic education. Transdisciplinary learning turns out to be a comprehensive innovation process in response to the major global challenges such as climate change, urbanization or migration. A reference work for students, lecturers, scientists, and anyone wanting to understand the profound changes in higher education

    Economic and Social Consequences of the COVID-19 Pandemic in Energy Sector

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    The purpose of the Special Issue was to collect the results of research and experience on the consequences of the COVID-19 pandemic for the energy sector and the energy market, broadly understood, that were visible after a year. In particular, the impact of COVID-19 on the energy sector in the EU, including Poland, and the US was examined. The topics concerned various issues, e.g., the situation of energy companies, including those listed on the stock exchange, mining companies, and those dealing with renewable energy. The topics related to the development of electromobility, managerial competences, energy expenditure of local government units, sustainable development of energy, and energy poverty during a pandemic were also discussed
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