cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A software for online monitoring of orientation-compensated forces during CI insertion
Creators: name: Schell, Viktor
name: Böttcher, Georg
name: Budde, Leon
name: Zuniga, M. Geraldine
name: Lenarz, Thomas
name: Rau, Thomas
Publisher: name: Berlin : De Gruyter
Year: 2021
Subjects: subject: CI insertion
subject: compensated force
subject: orientation compensated force
subject: software
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: The electrode array insertion is a critical point during CI surgery and should be performed as gently as possible to preserve residual hearing. In order to measure occurring forces, an insertion tool with an integrated force sensor and an inertial measurement unit (IM U) is being developed. The weight of the electrode holder and the sensor add an unknown offset to the measured forces, depending on the tool orientation. To address this problem, a software which calculates the orientation-induced error and computes a corrected force was developed. The software was written in C++ using the library Qt 5.12.9. For maximization of the computing frequency, the data acquisition of both sensors and the monitoring was parallelized. An algorithm was developed to calculate the error caused by the electrode holder and sensor. For this purpose both weights were determined in a calibration procedure and merged with the provided IM U data. The evaluation was done in two test series (each n=5) with different initial tool orientations. To this end a stepwise 360° rotation around the horizontal axis was performed, while recording the corrected forces. The developed software allows a computing frequency up to 100 Hz with a latency of 10 ms for the online monitoring of the processed data. The evaluation of the corrected force shows a residual error of 0.347 mN ± 0.325 mN for the first and 0.176 mN ± 1.971 mN for the second test series. With the created algorithm, the impact of the extra weight on the sensor can be almost fully equalized. The highly responsive software offers a new possibility to process insertion forces and provide feedback to surgeons. Determining the influence of the tool orientation on the corrected forces is the subject of future researches.
Effect of aging on tibiofemoral cartilage and meniscal stiffness
Creators: name: Ritchie, Brodie
Publisher: name: Graduate Studies
Year: 2017
Subjects: subject: Engineering--Biomedical
subject: dual fluoroscopy
subject: magnetic resonance imaging
subject: tibiofemoral cartilage
subject: meniscus
subject: Stiffness
subject: aging

description: Knee osteoarthritis (OA) is a prevalent degenerative cartilage disease characterized by degradation and loss of articular cartilage. Current OA diagnosis methods are ineffective at detecting and monitoring early signs of degeneration in the joint. Changes in mechanical properties of the tissue such as stiffness, or ability to resist compressive load, could present a more sensitive measure for the detection of early OA. This study has developed a novel methodology for the in-vivo measurement of tibiofemoral cartilage and meniscal stiffness using dual fluoroscopy (DF) and magnetic resonance (MR) imaging. This study further aimed to advance understanding of changes in cartilage and meniscal stiffness with normal aging, as age is generally believed to be a leading risk factor for OA. Two groups of five normal males (20-30 and 50-60 years of age) were tested to determine median cartilage and meniscal stiffness over a 5-minute static loading trial. Cartilage and meniscal stiffness was found to significantly increase by 12.51 N/mm (p=0.009) with age. The 20-30 year old group median was 3.39 N/mm (interquartile range (IQR)=2.01-7.29 N/mm) while the 50-60 year old group median was 15.90 N/mm (IQR=11.35-21.17 N/mm). This study contributes toward advancement of early OA clinical diagnostics by demonstrating the presence of significant changes in cartilage and meniscal stiffness with normal aging.
A Bayesian Spatial Model to Correct Under-Reporting in Urban Crowdsourcing
Creators: name: Agostini, Gabriel
name: Pierson, Emma
name: Garg, Nikhil
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computers and Society (cs.CY)
subject: Machine Learning (cs.LG)
subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Decision-makers often observe the occurrence of events through a reporting process. City governments, for example, rely on resident reports to find and then resolve urban infrastructural problems such as fallen street trees, flooded basements, or rat infestations. Without additional assumptions, there is no way to distinguish events that occur but are not reported from events that truly did not occur--a fundamental problem in settings with positive-unlabeled data. Because disparities in reporting rates correlate with resident demographics, addressing incidents only on the basis of reports leads to systematic neglect in neighborhoods that are less likely to report events. We show how to overcome this challenge by leveraging the fact that events are spatially correlated. Our framework uses a Bayesian spatial latent variable model to infer event occurrence probabilities and applies it to storm-induced flooding reports in New York City, further pooling results across multiple storms. We show that a model accounting for under-reporting and spatial correlation predicts future reports more accurately than other models, and further induces a more equitable set of inspections: its allocations better reflect the population and provide equitable service to non-white, less traditionally educated, and lower-income residents. This finding reflects heterogeneous reporting behavior learned by the model: reporting rates are higher in Census tracts with higher populations, proportions of white residents, and proportions of owner-occupied households. Our work lays the groundwork for more equitable proactive government services, even with disparate reporting behavior.
description: To appear in the 38th Annual AAAI Conference on Artificial Intelligence (AAAI-24)
Scaffolds with Magnetic Nanoparticles for Tissue Stimulation
Creators: name: Leal-Marin, Sara
name: Gallaway, Glynn
name: Höltje, Kai
name: Lopera-Sepulveda, Alex
name: Glasmacher, Birgit
name: Gryshkov, Oleksandr
Publisher: name: Berlin : De Gruyter
Year: 2021
Subjects: subject: biocompatibility
subject: electrospinning
subject: magnetic scaffolds
subject: mechanical testing
subject: tissue stimulation
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: Magnetic nanoparticles (MNPs) have been used in several medical applications, including targeted hyperthermia, resonance tomography, diagnostic sensors, and localized drug delivery. Further applications of magnetic field manipulation through MNPs in tissue engineering have been described. The current study aims to develop tissue-engineered polymeric scaffolds with incorporated MNPs for applications that require stimulation of the tissues such as nerves, muscles, or heart. Electrospun scaffolds were obtained using 14%w/v polycaprolactone (PCL) in 2,2,2-Trifluoroethanol (TFE) at concentrations of 5% & 7.5%w/v of dispersed MNPs (iron oxide, Fe3O4, or cobalt iron oxide, CoFe2O4). Scaffolds were analyzed using scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy, uniaxial tensile testing, and cell seeding for biocompatibility. Human bone marrow mesenchymal stem cells (bmMSCs) were seeded on the scaffolds. Biocompatibility was assessed by metabolic activity with Resazurin reduction assay on day 1, 3, 7, 10. Cell-cell and cell-scaffold interactions were analyzed by SEM. Electrospun scaffolds containing MNPs showed a decrease in fiber diameter as compared to scaffolds of pure PCL. The maximum force increases with the inclusion of MNPs, with higher values revealed for iron oxide. The metabolic activity decreased with MNPs, especially for cobalt iron oxide at a higher concentration. On the other hand, the cells developed good cell-scaffold and cell-cell interactions, making the proposed scaffolds good prospects for potential use in tissue stimulation.
Development of the Finite Difference Time Domain Method on a Lebedev Grid for Anisotropic Materials
Creators: name: Nauta, Marcel
Publisher: name: Graduate Studies
Year: 2012
Subjects: subject: Engineering--Electricity and Magnetism
subject: Computer Science
subject: Engineering--Electronics and Electrical
subject: FDTD
subject: Anisotropic Materials
subject: Computational Electromagnetics

description: The finite-difference time-domain (FDTD) method is derived on a Lebedev grid, instead of the standard Yee grid, to better represent the constitutive relations in anisotropic materials. The Lebedev grid extends the Yee grid by approximating Maxwell's equations with tensor constitutive relations using only central differences. A dispersion relation with stability criteria is derived and it is proven that the Lebedev grid has a consistent calculus. An integral derivation of the update equations illustrates how to appropriately excite the grid. This approach is also used to derive the update equations at planar material interfaces and domain edge PEC. Lebedev grid results are compared with analytical and Yee grid solutions using an equal memory comparison. Numerical results show that the Lebedev grid suffers greater dispersion error but better represents material interfaces. Focus is given to generalizing the concepts that make the Yee grid robust for isotropic materials.
Reducing the manual length setting error of a passive Gough-Stewart platform for surgical template fabrication using a digital measurement system
Creators: name: Kilian, Julia
name: Blum, Tobias
name: Laves, Max-Heinrich
name: Ortmaier, Tobias
name: Lenarz, Thomas
name: Rau, Thomas S.
Publisher: name: Berlin : De Gruyter
Year: 2021
Subjects: subject: accuracy setting
subject: digital display
subject: hexapod
subject: length measurement
subject: length setting error
subject: linear encoder
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: As recently demonstrated, a passive Gough-Stewart platform (a.k.a. hexapod) can be used to create a personalized surgical template to achieve minimally invasive access to the cochlea. The legs of the hexapod are manually adjusted to the desired length, which must be read off an analog scale. Previous experiments have shown that manual length setting of the hexapod's legs is error-prone because of the imprecise readability of the analog scale. The objective of this study is to determine if integration of a linear encoder and digitally displaying the measured length help reduce the length setting error. Two experiments were conducted where users set the leg length manually. In both experiments, the users were asked to set the leg length to 20 nominal values using the whole setting range from 0 mm to 10 mm. In the first experiment, users had to rely only on the analog scale; in the second experiment, the electronic display additionally showed the user the actual leg length. Results show that the mean length setting error without using the digital display and only relying on the analog scale was (0.036 ± 0.020) mm (max: 0.107 mm) in contrast to (0.001 ± 0.000) mm (max: 0.002 mm) for the experiment with the integrated digital measurement system. The results support integration of digital length measurement systems as a promising tool to increase the accuracy of surgical template fabrication and thereby patients' safety. Future studies must be conducted to evaluate if integration of a linear encoder in each of the six legs is feasible.
title: Die Rolle von Coenzym Q 10 in der medikamentösen Augentherapie
Creators: name: Erb, C.
Publisher: name: German Medical Science GMS Publishing House
Year: 2020
Subjects: subject: 610 Medical sciences; Medicine

description: Coenzym Q10 ist ein wichtiger Cofaktor in der mitochondrialen Atmungskette. Es ist an der Verstoffwechselung von freien Radikalen als Shuttlesystem zwischen den Komplexen I/II und III beteiligt, unterstützt die Bildung von ATP (den zellulären Energieträger), regeneriert membrangebundenes[zum vollständigen Text gelangen Sie über die oben angegebene URL]
description: 93. Versammlung des Vereins Rhein-Mainischer Augenärzte
Assuring Quality of Scaffolds in Musculoskeletal Tissue Engineering Mueller Matrix Polarimetry and Transillumination Imaging
Creators: name: Becker, Alexander
name: Fricke, Dierk
name: Roth, Bernhard
name: Glasmacher, Birgit
Publisher: name: Berlin : De Gruyter
Year: 2021
Subjects: subject: electrospinning
subject: fibre alignment
subject: fibre scaffolds
subject: Mueller matrix polarimetry
subject: polycaprolactone
subject: relative scaffold homogeneity
subject: Tissue engineering
subject: transillumination imaging
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: In order to achieve the high quality required in medical products, reliable characterization methods and quality management systems are necessary. In the field of musculoskeletal Tissue Engineering (mTE), electrospinning is utilized to manufacture fibre scaffolds as implant material. Depending on the application, in this case the regeneration of tendon-bone junctions, properties like the degree of fibre orientation, homogeneity of fibre throughout the scaffold and reaction to external mechanical load are of particular importance. Currently, destructive methods, like scanning electron microscopy (SEM), are widely used to determine these properties. In addition to the destruction of the samples, these methods often only allow the investigation of very small sections. In this study, we present two new methods for the fast, non-destructive and contactless characterization of electrospun fibre scaffolds for mTE. These methods are based on Transillumination Imaging (TI) and Mueller Matrix Polarimetry (MMP), utilizing low-power laser sources or LED light sources, respectively, to determine the relative homogeneity (TI) and the degree of fibre orientation (MMP) in electrospun fibre scaffolds.
title: Lamellär und schonend: neue Techniken zur minimal invasiven Hornhauttransplantation
Creators: name: Szurman, P.
Publisher: name: German Medical Science GMS Publishing House
Year: 2020
Subjects: subject: 610 Medical sciences; Medicine

description: Hintergrund: Zur Behandlung von Hornhauterkrankungen, denen ein Funktionsverlust des Endothels zugrunde liegt, hat sich die Descemet-Membran-Endothel-Keratoplastik (DMEK) zum Goldstandard entwickelt. Damit sind die Herausforderungen an die Transplantatherstellung durch den Operateur deutlich gestiegen.[zum vollständigen Text gelangen Sie über die oben angegebene URL]
description: 93. Versammlung des Vereins Rhein-Mainischer Augenärzte
Molecular Junctions Enhancing Thermal Transport within Graphene Polymer Nanocomposite: A Molecular Dynamics Study
Creators: name: Di Pierro, Alessandro
name: Mortazavi, Bohayra
name: Fina, Alberto
Publisher: name: Basel : MDPI
Year: 2021
Subjects: subject: Graphene
subject: Molecular junctions
subject: Polymer nanocomposites
subject: Thermal boundary resistance
subject: Thermal conductivity
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie
subject: Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie

description: Thermal conductivity of polymer-based (nano)composites is typically limited by thermal resistances occurring at the interfaces between the polymer matrix and the conductive particles as well as between particles themselves. In this work, the adoption of molecular junctions between thermally conductive graphene foils is addressed, aiming at the reduction of the thermal boundary resistance and eventually lead to an efficient percolation network within the polymer nanocomposite. This system was computationally investigated at the atomistic scale, using classical Molecular Dynamics, applied the first time to the investigation of heat transfer trough molecular junctions within a realistic environment for a polymer nanocomposite. A series of Molecular Dynamics simulations were conducted to investigate the thermal transport efficiency of molecular junctions in polymer tight contact, to quantify the contribution of molecular junctions when graphene and the molecular junctions are surrounded by polydimethylsiloxane (PDMS) molecules. A strong dependence of the thermal conductance was found in PDMS/graphene model, with best performances obtained with short and conformationally rigid molecular junctions. Furthermore, the adoption of the molecular linkers was found to contribute additionally to the thermal transport provided by the surrounding polymer matrix, demonstrating the possibility of exploiting molecular junctions in composite materials.
Remote Sensing for Property Valuation: A Data Source Comparison in Support of Fair Land Taxation in Rwanda
Creators: name: Koeva, Mila
name: Gasuku, Oscar
name: Lengoiboni, Monica
name: Asiama, Kwabena
name: Bennett, Rohan Mark
name: Potel, Jossam
name: Zevenbergen, Jaap
Publisher: name: Basel : MDPI
Year: 2021
Subjects: subject: Land
subject: Property taxation
subject: Property valuation
subject: Remote sensing
subject: UAV
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Remotely sensed data is increasingly applied across many domains, including fit-for-purpose land administration (FFPLA), where the focus is on fast, affordable, and accurate property information collection. Property valuation, as one of the main functions of land administration systems, is influenced by locational, physical, legal, and economic factors. Despite the importance of property valuation to economic development, there are often no standardized rules or strict data requirements for property valuation for taxation in developing contexts, such as Rwanda. This study aims at assessing different remote sensing data in support of developing a new approach for property valuation for taxation in Rwanda; one that aligns with the FFPLA philosophy. Three different remote sensing technologies, (i) aerial images acquired with a digital camera, (ii) WorldView2 satellite images, and (iii) unmanned aerial vehicle (UAV) images obtained with a DJI Phantom 2 Vision Plus quadcopter, are compared and analyzed in terms of their fitness to fulfil the requirements for valuation for taxation purposes. Quantitative and qualitative methods are applied for the comparative analysis. Prior to the field visit, the fundamental concepts of property valuation for taxation and remote sensing were reviewed. In the field, reference data using high precision GNSS (Leica) was collected and used for quantitative assessment. Primary data was further collected via semi-structured interviews and focus group discussions. The results show that UAVs have the highest potential for collecting data to support property valuation for taxation. The main reasons are the prime need for accurate-enough and up-to-date information. The comparison of the different remote sensing techniques and the provided new approach can support land valuers and professionals in the field in bottom-up activities following the FFPLA principles and maintaining the temporal quality of data needed for fair taxation.
Crystal Chemistry and Magnetic Properties of Manganese Zinc Alloy "YMn2Zn20" Comprising a Mn Pyrochlore Lattice
Creators: name: Okamoto, Yoshihiko
name: Shimizu, Takeshi
name: Yamaura, Jun-ichi
name: Hiroi, Zenji
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The chemical composition, crystal structure, and magnetic properties of a manganese zinc alloy with an ideal composition of YMn2Zn20, which comprises a pyrochlore lattice made of Mn atoms, are reported. The compound is stable only when In or Al is partially substituted for Zn. We have determined the actual chemical formula as YMn2+dZn20-x-dMx, with M = In or Al, and have identified the characteristic preferences with which the incorporated M and excess Mn atoms occupy the three crystallographic sites for Zn atoms. The Mn atoms in the pyrochlore lattice possess small magnetic moments that interact with each other antiferromagnetically but exhibit no long-range order above 0.4 K, probably owing to the geometrical frustration of the pyrochlore lattice. As a result, the effective mass of the conduction electrons is considerably enhanced, as observed in the related pyrochlore-lattice compounds (Y,Sc)Mn2 and LiV2O4. However, the presence of excess Mn atoms with large localized magnetic moments comparable to spin 5/2 tends to mask the inherent magnetism of the pyrochlore Mn atoms. It is suggested that "YMn2Zn18In2" with neither excess Mn atoms nor site disorder would be an ideal compound for further study.
description: 19 pages, 18 figures, accepted for publication in J. Solid State Chem
Classical bouncing Universes from vector fields
Creators: name: Artymowski, Michal
name: Lalak, Zygmunt
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: For the anisotropic Universe filled with massless vector field in the General Relativity frame we obtain bouncing solution for one of scale factors. We obtain the Universe with finite maximal energy density, finite value of $R,R^{μν}R_{μν},R^{μναβ}R_{μναβ}$ and non-zero value of a scale factor for directions transverse to a vector field. Such a bounce can be also obtained for a massive vector field with kinetic initial conditions, which gives isotropic low energy limit. We discuss the existence of a bounce for a massless vector field with additional matter fields, such as cosmological constant or dust. We also discuss bouncing solution for massless vector field domination in $n+2$ dimensional space-time.
description: 11 pages, 2 figures, plain LaTeX
Emergent Quadrupolar Order in the Spin-$1/2$ Kitaev-Heisenberg Model
Creators: name: Routh, Manodip
name: Ghosh, Sayan
name: Brink, Jeroen van den
name: Nishimoto, Satoshi
name: Kumar, Manoranjan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Motivated by the largely unexplored domain of multi-polar ordered spin states in the Kitaev-Heisenberg (KH) systems we investigate the ground state dynamics of the spin-$\frac{1}{2}$ KH model, focusing on quadrupolar (QP) order in 2-leg ladder and two-dimensional honeycomb lattice geometries. Employing exact diagonalization and density-matrix renormalization group methods, we analyze the QP order parameter and correlation functions. Our findings reveal a robust QP order across a wide range of the phase diagram, influenced by the interplay between Heisenberg and Kitaev interactions. Notably, we observe an enhancement of QP order near Kitaev quantum spin liquid (QSL) phases, despite the absence of long-range spin-spin correlations. This highlights a complex relationship between QP order and QSLs, offering new insights into quantum magnetism in low-dimensional systems. Our findings provide a rational explanation for the observed nonlinear magnetic susceptibility in $α$-RuCl$_3$.
Design and Evaluation of a Self-monitoring Application for Chronic Headaches
Creators: name: Rahman, S. M. Waliur
Publisher: name: Graduate Studies
Year: 2015
Subjects: subject: Computer Science
subject: Chronic Headaches
subject: Self-monitoring Application

description: Chronic headache sufferers use headache diaries to learn about their headache symptoms and triggers. But the existing headache diaries do not support identification of probable headache triggers which is a critical requirement for self-monitoring of headaches. The literature describes several applications that keep track of headaches, but none of them allow the patients to identify potential headache triggers by exploring the correlations between the self-tracked factors and the onset of headaches. In this thesis, a self-monitoring application is designed that supports reviewing of headache trends and enables interactive visual exploration of potential correlations between the headaches and the putative triggers based on temporal data analysis. The design of the application reflects the data collection and the analytical needs of the headache patients. The evaluation results suggest that the application can be useful for the headache patients to identify their potential headache triggers, and hence enable better self-monitoring of headaches.
Synthesis and Characterization of Modified Nanoclay for Polymer Nanocomposite Applications
Creators: name: Asgari, Mohammad
Publisher: name: Graduate Studies
Year: 2017
Subjects: subject: Chemistry
subject: Chemistry--Polymer
subject: Engineering--Chemical
subject: Materials Science
subject: Plastics Technology
subject: Nanoclay
subject: Functionalization
subject: Nanocomposites
subject: Hybrid Nanofiller
subject: Carbon nanotube
subject: Polymer

description: Polymer nanocomposites (PNCs) have several advantages, such as excellent mechanical properties, lightweight, durability, easy process-ability and low cost due to nanofiller high surface area. The main objective of this PhD thesis is to develop modified nanoclays for PNC, particularly high density polyethylene (HDPE) PNCs with enhanced mechanical and thermal properties. This has been accomplished by modifying the nanofiller constituents and optimizing the fabrication and processing methods. Different techniques for modifications were used depending on the end-use applications of the nanocomposites. These techniques were built upon a comprehensive understanding of the nanofiller structure and the modification type for PNC applications. The synthesized nanofiller and the nanocomposite’s final properties were investigated, and mechanical, thermal and rheological performance were characterized for PNC. In this PhD thesis, different nanoclays were synthesized and used as nanofiller in high density polyethylene. The resulting nanocomposites showed improvement in some mechanical and thermal properties. Different strategies were employed: (1) modification of nanofillers, (2) synthesis of novel nanofillers, (3) use of hybrid filler systems, and (4) and optimization of the processing conditions. For nanofiller modification, we performed chemical treatment of nanoclay and synthesis of hybrid clay/CNT. Functionalized clay was synthesized using silane coupling agents to take advantage of high thermal resistance of the silane coupling agents over traditionally used surfactants. The silane modified clay was further functionalized in a second reaction. The main objective of these strategies was to improve the affinity of polymer with clay, and increase interlayer space, and consequently, to increase dispersion of nanofillers in the host polymer to enhance PNC properties. Utilizing a secondary filler to further enhance the desired properties was another strategy. This was accomplished by synthesizing in situ hybrid CNT/clay nanofiller; that is, CNT was synthesized using CVD process directly on the clay silicate surface. Finally, we optimized PNC production methods (e.g., melt mixing, catalyst synthesis and clay functionalization). The aim of the last two strategies was to obtain improved mechanical and physical properties for the nanocomposite, and it is well known that nanocomposite structure can be used to control the final PNC properties.
title: Ρομποτική σμήνους. Νέες ιδέες, προοπτικές και μελλοντικές εφαρμογές.
Creators: name: Κατσιμπαλη Βασιλικη
Publisher: name: Technical University of Crete
Year: 2023

description: Η ρομποτική σμήνους είναι ένας νέος τομέας που εφαρμόζει τη ρομποτική στο
φαινόμενο των φυσικών σμηνών. Προκειμένου να δημιουργηθεί ένα σύστημα που να είναι επεκτάσιμο, προσαρμόσιμο και στιβαρό, οι ερευνητές μελετούν σμήνη ρομπότ που μιμούνται φυσικά σμήνη, όπως σμήνη μυρμηγκιών και πουλιών. Η αυτοοργάνωση, η αυτονομία, η συνεργασία και ο συντονισμός εμφανίζονται όλα από αυτά τα ρομπότ.
Προκειμένου να διατηρηθεί το κόστος και η πολυπλοκότητα του σχεδιασμού χαμηλά,
δημιουργούνται συστήματα που μοιάζουν πολύ με φυσικά σμήνη. Τα ρομπότ λειτουργούν ανεξάρτητα από έναν κεντρικό ελεγκτή και μπορούν να επικοινωνούν άμεσα (ρομπότ σε ρομπότ) ή έμμεσα (ρομπότ με περιβάλλον). Η ρομποτική σμήνους μπορεί να χρησιμοποιηθεί για μια ποικιλία εργασιών, από απλές δουλειές του σπιτιού έως στρατιωτικές επιχειρήσεις. Αυτό το δοκίμιο εξετάζει την ιστορία και τις δυνατότητες της τεχνικής της ρομποτικής σμήνους. Καλύπτει τις βασικές αρχές της ρομποτικής σμήνους καθώς και τα βασικά στοιχεία, τα έργα, τις προσομοιώσεις, τις εφαρμογές του πραγματικού κόσμου και τις πιθανές μελλοντικές κατευθύνσεις.
Simulating Parametric Thin Shells by Bicubic Hermite Elements
Creators: name: Ni, Xingyu
name: Chen, Xuwen
name: Yu, Cheng
name: Wang, Bin
name: Chen, Baoquan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Graphics (cs.GR)
subject: FOS: Computer and information sciences

description: In this study, we present the bicubic Hermite element method (BHEM), a new computational framework devised for the elastodynamic simulation of parametric thin-shell structures. The BHEM is constructed based on parametric quadrilateral Hermite patches, which serve as a unified representation for shell geometry, simulation, collision avoidance, as well as rendering. Compared with the commonly utilized linear FEM, the BHEM offers higher-order solution spaces, enabling the capture of more intricate and smoother geometries while employing significantly fewer finite elements. In comparison to other high-order methods, the BHEM achieves conforming $\mathcal{C}^1$ continuity for Kirchhoff-Love (KL) shells with minimal complexity. Furthermore, by leveraging the subdivision and convex hull properties of Hermite patches, we develop an efficient algorithm for ray-patch intersections, facilitating collision handling in simulations and ray tracing in rendering. This eliminates the need for laborious remodeling of the pre-existing parametric surface as the conventional approaches do. We substantiate our claims with comprehensive experiments, which demonstrate the high accuracy and versatility of the proposed method.
Metacognition in a gifted classroom : planning, note-taking, and checking for accuracy
Creators: name: Cotton, Graeme
Publisher: name: University of British Columbia
Year: 2010

description: Previous research indicates that planning, note-taking, and checking for accuracy encourage metacognitive awareness and better self-regulation. Facility with these particular metacognitive skills is important for researching and producing long-term projects, a major component of this program. Fourteen intellectually gifted grade four and five students in a gifted education class were instructed in the metacognitive strategies of planning, note-taking, and checking for accuracy over the course of one school year. This teacher directed study investigated if these students were capable of learning metacognitive strategies essential for successful self-regulated learning. Students were instructed in metacognitive strategies through a variety of highly interactive instructional techniques, including modelling, whole class activity, partner work, and independent assignments. Student work was evaluated by independent raters at the end of the study and was subjected to repeated measures of variance. The data demonstrates that explicit strategy instruction supports the development of metacognition in gifted grade four and five students. They are capable of learning to plan, note-take, and check for accuracy thus improving self-regulating behaviours.
Research in three acts : approaches to developing reserarch-based theatre
Creators: name: Lea, Graham Walter
Publisher: name: University of British Columbia
Year: 2010

description: This thesis explores the artistic development of three research-based theatre productions at The University of British Columbia faculty in 2009. Each was developed using one of the three approaches to research-based theatre identified in the literature: collective, combined:collective/playwright, and playwright-centered. The experience of working in each of the three approaches is closely examined in this descriptive / exploratory case study (Winston, 2006, p. 49) based primarily on my critical reflections. The discussions of the projects are stylistically independent; however, each is guided by two central questions (1) how meanings are constructed in each approach and (2) how each approach may create and inhibit meaning-making. In the first chapter, I propose research-based theatre as an umbrella term for the use of theatre in research. I also identify three approaches to developing research-based theatre and situate them in using examples from both scholars and theatre artists. The discussion of Drama as an Additional Language in chapter two attempts to weave research-based theatre with a/r/tography. Chapter three focuses on Naming the Shadows, exploring the complexities of adding additional artists in the playwright-centered approach. The development of Centering the Human Subject is used in chapter four to develop a scribe–artist continuum upon which the development of productions using the combined:collective/playwright may be better understood. The final chapter weaves script and prose to theatrically explore issues which cut across the three discussions and offer suggestions for further research and inquiry.
Stability of hexaquarks in the string limit of confinement
Creators: name: Vijande, Javier
name: Valcarce, Alfredo
name: Richard, Jean-Marc
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The stability of systems containing six quarks or antiquarks is studied within a simple string model inspired by the strong-coupling regime of quantum chromodynamics and used previously for tetraquarks and pentaquarks. We discuss both six-quark $(q^6)$ and three-quark--three-antiquark $ (q^3\bar q{}^3)$ states. The quarks are assumed to be distinguishable and thus not submitted to antisymmetrization. It is found that the ground state of $(q^6)$ is stable against dissociation into two isolated baryons. For the case of $ (q^3\bar q{}^3)$, our results indicate the existence of a bound state very close to the threshold. The investigations are extended to $(q^3Q^3)$ and $(Q^3\bar q^3)$ systems with two different constituent masses, and their stability is discussed as a function of the mass ratio.
description: 7pages, 7 figures
Engineering aspects of polypyrrole actuators and their application in active catheters
Creators: name: Shoa Hassani Lashidani, Tina
Publisher: name: University of British Columbia
Year: 2010

description: Polypyrrole has shown potential as an electrochemically driven artificial muscle. It has also been studied as an electromechanical sensor. Despite its potential as an engineering material, its actuation and sensing behaviours have not been fully characterized and modelled. In this thesis, polypyrrole is characterized in terms of electrochemical stability, mechanical stiffness and sensing capability. A link between actuation and sensing is also presented, suggesting a new mechanism of electromechanical coupling. An analytical model is developed to predict the dynamic actuation response. Finally, polypyrrole is applied to actively deform a catheter. Characterization studies were performed on a PF₆- (hexafluorophosphate) doped polypyrrole inside an aqueous solution of sodium hexafluorophosphate (NaPF₆) - a combination that has shown large repeatable actuation. Polypyrrole is found to be electrochemically stable from -0.4 V to 0.8 V versus an Ag/AgCl reference electrode. Its stiffness is a function of actuation voltage as well as the amplitude and the frequency of the applied load. Its sensitivity as a load sensor is ~ 4 x 10ˉ¹¹ V/Pa and it responds up to at least 100 Hz. A 2D transmission line model representing polypyrrole electrochemical properties (e.g. ionic and electronic conductivities and charge storage) is used to determine charging and hence actuation as a function of time and position. This model is coupled with a mechanical model to predict deflection and is used to design a polypyrrole driven catheter. The capability of polypyrrole to (1) manoeuvre catheters inside arteries and (2) scan catheter tips for imaging were evaluated by fabricating in vitro devices and testing their degree of bending and actuation speed. The feasibility of using the polypyrrole sensor as a feedback loop element on the catheter was also studied and the sensitivity was found to be insufficient for practical use. Polypyrrole driven catheters are able to provide the degree of bending needed for manoeuvring; however actuation speed needs to be improved for the imaging application investigated, which requires operation at frequencies > 10 Hz. According to the model polypyrrole electrodes with thin conductive backings on a flexible catheter can provide the required scanning speed. Further work is required to create encapsulated designs which contain the electrolyte needed for actuation.
Note on a paradox in decision-theoretic interval estimation
Creators: name: Kabaila, Paul
Publisher: name: arXiv
Year: 2012
Subjects: subject: Statistics Theory (math.ST)
subject: Methodology (stat.ME)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: Confidence intervals are assessed according to two criteria, namely expected length and coverage probability. In an attempt to apply the decision-theoretic method to finding a good confidence interval, a loss function that is a linear combination of the interval length and the indicator function that the interval includes the parameter of interest has been proposed. We consider the particular case that the parameter of interest is the normal mean, when the variance is unknown. Casella, Hwang and Robert, Statistica Sinica, 1993, have shown that this loss function, combined with the standard noninformative prior, leads to a generalized Bayes rule that is a confidence interval for this parameter which has "paradoxical behaviour". We show that a simple modification of this loss function, combined with the same prior, leads to a generalized Bayes rule that is the usual confidence interval i.e. the "paradoxical behaviour" is removed.
Temporal variations in the evaporating atmosphere of the exoplanet HD 189733b
Creators: name: Etangs, A. Lecavelier des
name: Bourrier, V.
name: Wheatley, P. J.
name: Dupuy, H.
name: Ehrenreich, D.
name: Vidal-Madjar, A.
name: Hébrard, G.
name: Ballester, G. E.
name: Désert, J. -M.
name: Ferlet, R.
name: Sing, D. K.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Atmospheric escape has been detected from the exoplanet HD 209458b through transit observations of the hydrogen Lyman-alpha line. Here we present spectrally resolved Lyman-alpha transit observations of the exoplanet HD 189733b at two different epochs. These HST/STIS observations show for the first time, that there are significant temporal variations in the physical conditions of an evaporating planetary atmosphere. While atmospheric hydrogen is not detected in the first epoch observations, it is observed at the second epoch, producing a transit absorption depth of 14.4+/-3.6% between velocities of -230 to -140 km/s. Contrary to HD 209458b, these high velocities cannot arise from radiation pressure alone and require an additional acceleration mechanism, such as interactions with stellar wind protons. The observed absorption can be explained by an atmospheric escape rate of neutral hydrogen atoms of about 10^9 g/s, a stellar wind with a velocity of 190 km/s and a temperature of ~10^5K. An X-ray flare from the active star seen with Swift/XRT 8 hours before the second-epoch observation supports the idea that the observed changes within the upper atmosphere of the planet can be caused by variations in the stellar wind properties, or by variations in the stellar energy input to the planetary escaping gas (or a mix of the two effects). These observations provide the first indication of interaction between the exoplanet's atmosphere and stellar variations.
description: To be published in A&A Letters, June 28, 2012
[Halle (Saale), Universitäts- und Landesbibliothek Sachsen-Anhalt, Morbio 1 (17)]
Creators: name: , Petrus
Publisher: name: Universitäts- und Landesbibliothek Sachsen-Anhalt
Year: 1056
Subjects: subject: Vertrag
subject: Notarsurkunde
subject: Urkunde
subject: 090

description: Ubaldus, Bischof von Cremona, und Johannes aus Cremona, genannt Ualario, Sohn des Petrus, tauschen unterhalb von Cremona gelegene Güter
Many faces, many frames : exploring the dimensions of justice and climate change policy decision-making
Creators: name: Klinsky, Sonja
Publisher: name: University of British Columbia
Year: 2010

description: Climate change presents profound justice dilemmas because of its asymmetrical costs and benefits. This is complicated by the tendency of both climate change and justice to change their appearance across contexts. This dissertation explores how arguments about justice are used in debates about how climate policy should be designed. Part A focuses on how arguments about justice have been used in debates about ideal architectures for international climate policy. A framework for analysing international climate policy proposals is developed using literature from both the philosophy and policy analysis communities. This analysis identifies three archetypal approaches to climate change policy at this level, each of which has potential justice implications. Part B explores public perceptions of justice in mitigation and adaptation climate policy contexts. This section creates and applies a methodology to explore the arguments about justice considered relevant by lay public participants in a series of climate policy decision dilemmas. Among other results, this part highlights the importance of framing in considerations of justice in climate policy. Finally, Part C explores climate policy dilemmas currently faced by policy insiders at the sub-national level, and cross-examines the views policy-insiders and the public think each other have on these issues. This part of the thesis identifies a range of specific justice dilemmas at the sub-national level. It also suggests that mis-communication between policy insiders and the public may limit the range of climate policies considered politically feasible. Four lessons emerge from this dissertation. First, justice is pragmatically important when developing climate policy. Second, there has been a systemic lack of integration across academic, policy and public communities on questions of justice and climate policy. Third, climate change and justice have multiple faces. How climate change policy decisions are framed will shape the arguments stakeholders are likely to consider relevant. Finally, methodologically a mixed methods approach may be of use in other similarly ambiguous research contexts. Overall, explicit recognition of the importance and complexity of justice in climate policy decision-making may help us design more effective and desirable climate policies.
Fransiska Louwagie, Témoignage et littérature d’après Auschwitz
Creators: name: El Hajj, Murielle
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 470516
subject: Literature in French
classificationCode: 470599
subject: Literary studies not elsewhere classified

description: Dans Témoignage et littérature d’après Auschwitz, Fransiska Louwagie offre des études critiques provenant de deux centres de gravité de la littérature de la Shoah et des camps nazis : les œuvres des témoins-survivants et celles des générations suivantes. Le livre explore les travaux des écrivains suivants : Robert Antelme, André Schwarz-Bart, Piotr Rawicz, Jorge Semprun, Imre Kertész, Georges Perec, Raymond Federman, Gérard Wajcman, Henri Raczymow et Michel Kichka. Il étudie les œuvres-témoignages des auteurs précités dans leurs différences et leurs points de suture afin de penser une littérature d’après, avec ses inquiétudes, scrupules et défis éthiques (p. 2). Il porte sur une étude comparative des témoins et écrivains héritiers visant à dégager la conscience littéraire qui s’est forgée depuis et après Auschwitz.
Electromagnetic Radiation from Binary Stars Mediated by Ultralight Scalar
Creators: name: Cheng, Ya-Ze
name: Wu, Wen-Hao
name: Cao, Yan
Publisher: name: arXiv
Year: 2024
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present the electromagnetic (EM) dipole radiation flux from an eccentric Keplerian binary endowed with scalar charges, in the presence of scalar-photon coupling $ϕA_μA^μ$ or $ϕF_{μν}F^{μν}$. The scalar radiation is suppressed for orbital frequency below the scalar mass, while the scalar-mediated indirect EM radiation survives. We examine the constraints imposed on the scalar-photon and scalar-charge couplings by the current observational data, in case that the scalar charge is given by the muon number. The extensions of our calculation to the quadrupole order and hyperbolic orbit are also discussed.
description: 29 pages, 5 figures, 2 tables; accepted for publication in International Journal of Modern Physics D
Dark Matter as an active gravitational agent in cloud complexes
Creators: name: Suárez-Madrigal, Andrés
name: Ballesteros-Paredes, Javier
name: Colín, Pedro
name: D'Alessio, Paola
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study the effect that the dark matter background (DMB) has on the gravitational energy content and, in general, on the star formation efficiency of a molecular cloud (MC). We first analyze the effect that a dark matter halo, described by the Navarro et al. (1996) density profile, has on the energy budget of a spherical, homogeneous, cloud located at different distances from the halo center. We found that MCs located in the innermost regions of a massive galaxy can feel a contraction force greater than their self-gravity due to the incorporation of the potential of the galaxy's dark matter halo. We also calculated analytically the gravitational perturbation that a MC produces over a uniform DMB (uniform at the scales of a MC) and how this perturbation will affect the evolution of the MC itself. The study shows that the star formation in a MC will be considerably enhanced if the cloud is located in a dense and low velocity dark matter environment. We confirm our results by measuring the star formation efficiency in numerical simulations of the formation and evolution of MCs within different DMBs. Our study indicates that there are situations where the dark matter's gravitational contribution to the evolution of the molecular clouds should not be neglected.
description: Same as previous version, but accepted by the Astrophysical Journal; 12 pages, 12 figures