Connecting visual and analytic reasoning to improve students' spatial visualization abilities: A constructivist approach

Current reform initiatives recommend that school geometry teaching and learning include the study of three-dimensional geometric objects and provide students with opportunities to use spatial abilities in mathematical tasks. Two ways of using Geometer's Sketchpad (GSP), a dynamic and interactive computer program, in conjunction with manipulatives enable students to investigate and explore geometric concepts, especially when used in a constructivist setting. Research on spatial abilities has focused on visual reasoning to improve visualization skills. This dissertation investigated the hypothesis that connecting visual and analytic reasoning may better improve students' spatial visualization abilities as compared to instruction that makes little or no use of the connection of the two. Data were collected using the Purdue Spatial Visualization Tests (PSVT) administered as a pretest and posttest to a control and two experimental groups. Sixty-four 10th grade students in three geometry classrooms participated in the study during 6 weeks. Research questions were answered using statistical procedures. An analysis of covariance was used for a quantitative analysis, whereas a description of students' visual-analytic processing strategies was presented using qualitative methods. The quantitative results indicated that there were significant differences in gender, but not in the group factor. However, when analyzing a sub sample of 33 participants with pretest scores below the 50th percentile, males in one of the experimental groups significantly benefited from the treatment. A review of previous research also indicated that students with low visualization skills benefited more than those with higher visualization skills. The qualitative results showed that girls were more sophisticated in their visual-analytic processing strategies to solve three-dimensional tasks. It is recommended that the teaching and learning of spatial visualization start in the middle school, prior to students' more rigorous mathematics exposure in high school. A duration longer than 6 weeks for treatments in similar future research studies is also recommended.

The discrimination and association of float glass and the quantitative analysis of liquids from aerosols and microdrops using laser induced breakdown spectroscopy

Glass is a common form of trace evidence found at many scenes of crimes in the form of small fragments. These glass fragments can transfer to surrounding objects and/or persons and may provide forensic investigators valuable information to link a suspect to the scene of a crime. Since the elemental composition of different glass sources can be very similar, a highly discriminating technique is required to distinguish between fragments that have originated from different sources. ^ The research presented here demonstrates that Laser Induced Breakdown Spectroscopy (LIBS) is a viable analytical technique for the association and discrimination of glass fragments. The first part of this research describes the optimization of the LIBS experiments including the use of different laser wavelengths to investigate laser-material interaction. The use of a 266 nm excitation laser provided the best analytical figures of merit with minimal damage to the sample. The resulting analytical figures of merit are presented. The second part of this research evaluated the sensitivity of LIBS to associate or discriminate float glass samples originating from the same manufacturing plants and produced at approximately the same time period. Two different sample sets were analyzed ranging in manufacturing dates from days to years apart. Eighteen (18) atomic emission lines corresponding to the elements Sr, K, Fe, Ca, Al, Ba, Na, Mg and Ti, were chosen because of their detection above the method detection limits and for presenting differences between the samples. Ten elemental ratios producing the most discrimination were selected for each set. When all the ratios are combined in a comparison, 99% of the possible pairs were discriminated using the optimized LIBS method generating typical analytical precisions of ∼5% RSD. ^ The final study consisted of the development of a new approach for the use of LIBS as a quantitative analysis of ultra-low volume solution analysis using aerosols and microdrops. Laser induced breakdown spectroscopy demonstrated to be an effective technique for the analysis of as low as 90 pL for microdrop LIBS with 1 pg absolute LOD and 20 µL for aerosol LIBS with an absolute LOD of ∼100 fg.^

Search for associations containing young stars (SACY). VII. New stellar and substellar candidate members in the young associations

Context. The young associations offer us one of the best opportunities to study the properties of young stellar and substellar objects and to directly image planets thanks to their proximity (<200 pc) and age (≈5−150 Myr). However, many previous works have been limited to identifying the brighter, more active members (≈1 M_⊙) owing to photometric survey sensitivities limiting the detections of lower mass objects. Aims. We search the field of view of 542 previously identified members of the young associations to identify wide or extremely wide (1000−100 000 au in physical separation) companions. Methods. We combined 2MASS near-infrared photometry (J, H, K) with proper motion values (from UCAC4, PPMXL, NOMAD) to identify companions in the field of view of known members. We collated further photometry and spectroscopy from the literature and conducted our own high-resolution spectroscopic observations for a subsample of candidate members. This complementary information allowed us to assess the efficiency of our method. Results. We identified 84 targets (45: 0.2−1.3 M_⊙, 17: 0.08−0.2 M_⊙, 22: <0.08 M_⊙) in our analysis, ten of which have been identified from spectroscopic analysis in previous young association works. For 33 of these 84, we were able to further assess their membership using a variety of properties (X-ray emission, UV excess, Hα, lithium and K I equivalent widths, radial velocities, and CaH indices). We derive a success rate of 76–88% for this technique based on the consistency of these properties. Conclusions. Once confirmed, the targets identified in this work would significantly improve our knowledge of the lower mass end of the young associations. Additionally, these targets would make an ideal new sample for the identification and study of planets around nearby young stars. Given the predicted substellar mass of the majority of these new candidate members and their proximity, high-contrast imaging techniques would facilitate the search for new low-mass planets.

Mechanochemistry for Active Materials and Devices

The coupling of mechanical stress fields in polymers to covalent chemistry (polymer mechanochemistry) has provided access to previously unattainable chemical reactions and polymer transformations. In the bulk, mechanochemical activation has been used as the basis for new classes of stress-responsive polymers that demonstrate stress/strain sensing, shear-induced intermolecular reactivity for molecular level remodeling and self-strengthening, and the release of acids and other small molecules that are potentially capable of triggering further chemical response. The potential utility of polymer mechanochemistry in functional materials is limited, however, by the fact that to date, all reported covalent activation in the bulk occurs in concert with plastic yield and deformation, so that the structure of the activated object is vastly different from its nascent form. Mechanochemically activated materials have thus been limited to “single use” demonstrations, rather than as multi-functional materials for structural and/or device applications. Here, we report that filled polydimethylsiloxane (PDMS) elastomers provide a robust elastic substrate into which mechanophores can be embedded and activated under conditions from which the sample regains its original shape and properties. Fabrication is straightforward and easily accessible, providing access for the first time to objects and devices that either release or reversibly activate chemical functionality over hundreds of loading cycles.

While the mechanically accelerated ring-opening reaction of spiropyran to merocyanine and associated color change provides a useful method by which to image the molecular scale stress/strain distribution within a polymer, the magnitude of the forces necessary for activation had yet to be quantified. Here, we report single molecule force spectroscopy studies of two spiropyran isomers. Ring opening on the timescale of tens of milliseconds is found to require forces of ~240 pN, well below that of previously characterized covalent mechanophores. The lower threshold force is a combination of a low force-free activation energy and the fact that the change in rate with force (activation length) of each isomer is greater than that inferred in other systems. Importantly, quantifying the magnitude of forces required to activate individual spiropyran-based force-probes enables the probe behave as a “scout” of molecular forces in materials; the observed behavior of which can be extrapolated to predict the reactivity of potential mechanophores within a given material and deformation.

We subsequently translated the design platform to existing dynamic soft technologies to fabricate the first mechanochemically responsive devices; first, by remotely inducing dielectric patterning of an elastic substrate to produce assorted fluorescent patterns in concert with topological changes; and second, by adopting a soft robotic platform to produce a color change from the strains inherent to pneumatically actuated robotic motion. Shown herein, covalent polymer mechanochemistry provides a viable mechanism to convert the same mechanical potential energy used for actuation into value-added, constructive covalent chemical responses. The color change associated with actuation suggests opportunities for not only new color changing or camouflaging strategies, but also the possibility for simultaneous activation of latent chemistry (e.g., release of small molecules, change in mechanical properties, activation of catalysts, etc.) in soft robots. In addition, mechanochromic stress mapping in a functional actuating device might provide a useful design and optimization tool, revealing spatial and temporal force evolution within the actuator in a way that might also be coupled to feedback loops that allow autonomous, self-regulation of activity.

In the future, both the specific material and the general approach should be useful in enriching the responsive functionality of soft elastomeric materials and devices. We anticipate the development of new mechanophores that, like the materials, are reversibly and repeatedly activated, expanding the capabilities of soft, active devices and further permitting dynamic control over chemical reactivity that is otherwise inaccessible, each in response to a single remote signal.

Everyday Enchantments and Secular Magic in Montréal

In this thesis I argue that dominant ways of imagining modernity constitute a modern imaginary that carries with it particular expectations concerning modern places, spaces, emotions, and affects as well as expectations concerning the place of religion and enchantment in the modern world. I argue that this modern imaginary and the expectations it entails works to conceal and trivialize supra-rational beliefs and behaviours in scholarship but also in the lives of individuals. I focus on one particular subset of the supra-rational beliefs and behaviours that modern imaginary conceals and trivializes, namely beliefs and behaviours associated with lucky and protective objects. I also focus on the ways the modern imaginary conceals the presence and prevalence of these objects and the beliefs and behaviours they entail in one particular context, namely Montréal, Québec. I argue that these supra-rational beliefs and behaviours constitute a subjunctive mode for understanding and experiencing daily life and describe how the modern imaginary works to discredit this subjunctive register. Finally, I argue that scholars must begin to recognize and examine this subjunctive mode and the playful engagement with half-belief it involves.

CERAMICS IN BRITAIN (1840-90): MEANINGS AND METAPHORS

The intention of this thesis, “Ceramics in Britain (1840–90): Meanings and Metaphors” is to present new approaches for interpreting ceramics in nineteenth-century Britain by situating, problematizing, and contextualizing pottery and porcelain in the popular debates of the day within the methodologies of material culture, design, cultural and art histories. I ask how did ceramics—portable, functional, and often decorative objects—contribute to shaping modes of experiences? Crockery, tableware and blue-white-porcelain, admittedly largely mediated in texts and paintings, are at the centre of this research to examine how they imposed symbolism and influenced the engagement of their subjects beyond their intended meanings and functions. This thesis tracks a common rhetoric shared by writers and artists across genres and understood by readers and viewers: crockery in the cupboard, on the mantel, the table or the floor were popular motifs exemplifying class, gender, character, etiquette, and taste. This thesis also seeks to map ceramics’ relations with other objects and people depicted. Their meanings and metaphors changed, depending on their exchange with other objects in the room and who uses them. The conventions of representing ceramics dictated a particular grammar that writers and artists used, critiqued, discarded or personalized. The examination of ceramics mediated in text and image especially in comparison with extant objects invites a deeper probing of both material culture and artistic practice, which helps to situate the agency of the ceramic objects themselves. Also this thesis, in attempt to explore new methodological approaches for ceramic studies, examines the social life of the mid-Victorian relief-moulded “Minster” Jug in the Gardiner Museum in Toronto. The product originating in Staffordshire in 1843 and exported to the colonies holds significance due to its multiple life histories. Viewing the “Minster” through the lenses of curator, collector, consumer, and critic its layered lives unfold to reveal the protocols of museum praxis as well as important aspects of mid-nineteenth-century British society related to design reform, gender, imperialism and consumption patterns. This thesis contends that the British experienced ceramics in sometimes unexpected ways, unrelated to their original purpose, such as tools of violence or containers of solace, and transformative fantasy.

Performance Evaluation of a Statistical and a Neural Network Model for Nonrigid Shape-Based Registration

Shape-based registration methods frequently encounters in the domains of computer vision, image processing and medical imaging. The registration problem is to find an optimal transformation/mapping between sets of rigid or nonrigid objects and to automatically solve for correspondences. In this paper we present a comparison of two different probabilistic methods, the entropy and the growing neural gas network (GNG), as general feature-based registration algorithms. Using entropy shape modelling is performed by connecting the point sets with the highest probability of curvature information, while with GNG the points sets are connected using nearest-neighbour relationships derived from competitive hebbian learning. In order to compare performances we use different levels of shape deformation starting with a simple shape 2D MRI brain ventricles and moving to more complicated shapes like hands. Results both quantitatively and qualitatively are given for both sets.

These things are alive: relationships between material culture, communities, and archaeological legislation

This paper deals with the relationship between different sets of archaeological legislation, material culture and communities. First it presents a historical sketch of the heritage legislation in the West and its contemporary uses. Secondly, it shows how alternative archaeological agencies, such as community archaeology, deal with these problems. The discussion is especially relevant in Brazil, where contract archaeology is presently overwhelming, and the issue is raised in the last part of the paper.

Photoionization of Co+ and electron-impact excitation of Co2 + using the Dirac R-matrix method

Modelling of massive stars and supernovae (SNe) plays a crucial role in understanding galaxies. From this modelling we can derive fundamental constraints on stellar evolution, mass-loss processes, mixing, and the products of nucleosynthesis. Proper account must be taken of all important processes that populate and depopulate the levels (collisional excitation, de-excitation, ionization, recombination, photoionization, bound–bound processes). For the analysis of Type Ia SNe and core collapse SNe (Types Ib, Ic and II) Fe group elements are particularly important. Unfortunately little data is currently available and most noticeably absent are the photoionization cross-sections for the Fe-peaks which have high abundances in SNe. Important interactions for both photoionization and electron-impact excitation are calculated using the relativistic Dirac atomic R-matrix codes (DARC) for low-ionization stages of Cobalt. All results are calculated up to photon energies of 45 eV and electron energies up to 20 eV. The wavefunction representation of Co III has been generated using GRASP0 by including the dominant 3d⁷, 3d⁶[4s, 4p], 3p⁴3d⁹ and 3p⁶3d⁹ configurations, resulting in 292 fine structure levels. Electron-impact collision strengths and Maxwellian averaged effective collision strengths across a wide range of astrophysically relevant temperatures are computed for Co III. In addition, statistically weighted level-resolved ground and metastable photoionization cross-sections are presented for Co II and compared directly with existing work.

Web-based museum trails on PDAs for university-level design students: Design and evaluation

This paper describes the development and evaluation of web-based museum trails for university-level design students to access on handheld devices in the Victoria and Albert Museum (V&A) in London. The trails offered students a range of ways of exploring the museum environment and collections, some encouraging students to interpret objects and museum spaces in lateral and imaginative ways, others more straightforwardly providing context and extra information. In a three-stage qualitative evaluation programme, student feedback showed that overall the trails enhanced students’ knowledge of, interest in, and closeness to the objects. However, the trails were only partially successful from a technological standpoint due to device and network problems. Broader findings suggest that technology has a key role to play in helping to maintain the museum as a learning space which complements that of universities as well as schools. This research informed my other work in visitor-constructed learning trails in museums, specifically in the theoretical approach to data analysis used, in the research design, and in informing ways to structure visitor experiences in museums. It resulted in a conference presentation, and more broadly informed my subsequent teaching practice.

Revising Devotion: the role of wooden sculptures in affecting painting and devotion in the Late Medieval period in Italy (XII-XV century)

Thesis (Ph.D.)--University of Washington, 2016-06

Applications of a Collaborative Open Object Oriented Learning Environment to Electronics, Computing and Mathematics Education

A lightweight Java application suite has been developed and deployed allowing collaborative learning between students and tutors at remote locations. Students can engage in group activities online and also collaborate with tutors. A generic Java framework has been developed and applied to electronics, computing and mathematics education. The applications are respectively: (a) a digital circuit simulator, which allows students to collaborate in building simple or complex electronic circuits; (b) a Java programming environment where the paradigm is behavioural-based robotics, and (c) a differential equation solver useful in modelling of any complex and nonlinear dynamic system. Each student sees a common shared window on which may be added text or graphical objects and which can then be shared online. A built-in chat room supports collaborative dialogue. Students can work either in collaborative groups or else in teams as directed by the tutor. This paper summarises the technical architecture of the system as well as the pedagogical implications of the suite. A report of student evaluation is also presented distilled from use over a period of twelve months. We intend this suite to facilitate learning between groups at one or many institutions and to facilitate international collaboration. We also intend to use the suite as a tool to research the establishment and behaviour of collaborative learning groups. We shall make our software freely available to interested researchers.

Governing through parents: a genealogical enquiry of education policy and the construction of neoliberal subjectivities in England

In this paper we explore the various spaces and sites through which the figure of the parent is summoned and activated to inhabit and perform market norms and practices in the field of education in England. Since the late 1970s successive governments have called on parents to enact certain duties and obligations in relation to the state. These duties include adopting and internalizing responsibility for all kinds of risks, liabilities and inequities formerly managed by the Keynesian welfare state. Rather than characterize this situation in terms of the ‘hollowing of the state’, we argue that the role of the state includes enabling the functioning of the parent as a neoliberal subject so that they may successfully harness the power of the market to their own advantage and (hopefully) minimize the kinds of risk and inequity generated through a market-based, deregulated education system. In this paper we examine how parents in England are differently, yet similarly, compelled to embody certain market norms and practices as they navigate the field of education. Adopting genealogical enquiry and policy discourse analysis as our methodology, we explore how parents across three policy sites or spaces are constructed as objects and purveyors of utility and ancillaries to marketisation. This includes a focus on how parents are summoned as 1) consumers or choosers of education services; 2) governors and overseers of schools; and 3) producers and founders of schools.

The Object Animates: Displacement and Humility in the Theatre of Philippe Quesne

This article considers the animating role that objects play in the theatre of Philippe Quesne and Vivarium Studio (France). The conventional role of object animation is often characterised by the performer manipulating objects and scenic material on the stage, asserting a control over the environment they are implicated in. In Quesne's theatre, this relationship is democratised. The theatrical apparatus, both materially and conceptually, is set up to enable the flow of animation to be interchangeable, affording an equal agency to the objects being used much as that of the performers. This theatre of animation is drawn through the framing concepts of displacement and humility. Displacement is considered as a compositional strategy that makes us aware of the volume of the stage space beyond the proscenium frame as a plane of composition. The introduction of large inflatable objects, real cars or large roles of fake snow foreground the objects material presence allows Quesne to play with moments of equilibrium, tipping, excess and absence. Humility is traced as a philosophy of objects that transcends the choice, handling and use of material items in Quesne's work. Simple objects take on a specific vibrancy because of how they give shape to the human participants on stage, animating moments of recognition that allows the human figure, its ethics, emotions and humour, to appear.

What Does Value Matter? The Interest-Relational Theory of the Semantics and Metaphysics of Value

Value and reasons for action are often cited by rationalists and moral realists as providing a desire-independent foundation for normativity. Those maintaining instead that normativity is dependent upon motivation often deny that anything called '"value" or "reasons" exists. According to the interest-relational theory, something has value relative to some perspective of desire just in case it satisfies those desires, and a consideration is a reason for some action just in case it indicates that something of value will be accomplished by that action. Value judgements therefore describe real properties of objects and actions, but have no normative significance independent of desires. It is argued that only the interest-relational theory can account for the practical significance of value and reasons for action. Against the Kantian hypothesis of prescriptive rational norms, I attack the alleged instrumental norm or hypothetical imperative, showing that the normative force for taking the means to our ends is explicable in terms of our desire for the end, and not as a command of reason. This analysis also provides a solution to the puzzle concerning the connection between value judgement and motivation. While it is possible to hold value judgements without motivation, the connection is more than accidental. This is because value judgements are usually but not always made from the perspective of desires that actually motivate the speaker. In the normal case judgement entails motivation. But often we conversationally borrow external perspectives of desire, and subsequent judgements do not entail motivation. This analysis drives a critique of a common practice as a misuse of normative language. The "absolutist" attempts to use and, as philosopher, analyze normative language in such a way as to justify the imposition of certain interests over others. But these uses and analyses are incoherent - in denying relativity to particular desires they conflict with the actual meaning of these utterances, which is always indexed to some particular set of desires.