The sounds of displacement : a portfolio of binaural compositions

The portfolio presented comprises of five binaural acousmatic works composed primarily for headphone reproduction but also for multi-channel loudspeaker concert diffusion. The commentary traverses the programmatic and aesthetic considerations involved in the construction of the portfolio and the influence of the in-ear binaural method of recording and reproduction thereof. The spectral watermark (the effect of the recordist on the resulting recording), negative space (the space left by the recordist, subsequently occupied by the listener), spatial strategy and the contextually rich results of the method are discussed, along with their creative applications within the portfolio

Heidegger’s conception of freedom 1927-1930: guilt, transcendence, truth

This thesis investigates Heidegger’s concept of freedom between 1927 and 1930. In it, I argue that Heidegger advocates a radical reinvention of the positive concept of freedom in confrontation with Immanuel Kant and Henri Bergson. I also argue, against the grain of recent literature, that this conception remains the same as it is found in Being and Time and in the key texts concerning freedom from the period immediately after its publication: ‘The Essence of Ground’ [WG], Metaphysical Foundations of Logic [GA26], The Essence of Human Freedom [GA31], and ‘On the Essence of Truth’ [WW]. In Chapter 1, I interpret the argument of the lecture course The Essence of Human Freedom as Heidegger’s attempt to dismiss the question of the freedom of the will. In doing so, I argue, he critically repeats the arguments that Bergson provides in Time and Free Will. In Chapter 2, I turn to Being and Time to follow the thread of Heidegger’s argument, leading to the claim that Dasein is fundamentally free but, as inauthentic, also typically unfree. In Chapter 3 I investigate this apparent paradox further, showing that Heidegger, without using the term, is advocating a positive, rather than a negative, conception of unfreedom in evaluating inauthentic Dasein as unfree. In Chapter 4, I show how this positive conception also arrives as a critical confrontation with Kant and Bergson, where authenticity is conceived as Dasein’s being-its-self in an ontological sense. In Chapter 5, I build on the above to demonstrate that the arguments in Being and Time concerning guilt, the arguments in WG and GA26 concerning transcendence, and the arguments in WW concerning truth all complement each other in a single concept of freedom: Dasein’s being its self by choosing to be the ground of its world, rather than fleeing from this existential responsibility

Program Profile 8: Chapman University: Bridging the Gap with Action Research

In the English Department at Chapman, all graduate students are eligible to apply for positions as GTAs after they have completed a graduate seminar in teaching composition. Those who are offered and accept GTA positions take a second graduate seminar, composition pedagogy and research practicum, simultaneously with their first semester of teaching. In order to encourage GTAs to develop identities as teacher-scholars, GTAs develop IRB-approved action research projects (Buyserie; Hawkes; Hudson et al.; Souleles) as their major work in this second seminar. These action research projects allow GTAs to research a question they have about the teaching of composition, using their own students as the sources of their data. Thus, they are learning how (their own) teacher-knowledge can be a source of expertise in the fields of pedagogy and composition, and the action research project becomes a central component of and bridge between their teaching (their identities as teachers, since they initiate, shape, and undertake the research as the instructor of their first-year composition class) and their scholarship (their identities as students, since they are learning how to undertake an action research project and are completing it as a graduate student assignment). Many GTAs have gone on to use their action research projects as the basis for MA theses and conference papers.https://digitalcommons.chapman.edu/english_books/1039/thumbnail.jp

Model-Based Software for Simulating Ultrasonic Pulse/Echo Inspections of Metal Components

The use of models to simulate inspections has played a key role in UT NDE R&D efforts. Over the years, a series of wave propagation models, flaw response models, and microstructural backscatter models have been developed at CNDE to address inspection problems of interest. One use of the combined models is the estimation of signal-to-noise ratios (S/N) in circumstances where backscattered echoes from the microstructure (grain noise) act to mask sonic echoes from internal defects. Such S/N models have been used to address questions of inspection reliability, such as how to optimize the choices of transducer properties and inspection design to insure that critical defects are reliably detected. Under the sponsorship of the National Science Foundation\u27s Industry/University Cooperative Research Center at ISU, an effort was initiated in 2015 to repackage existing research-grade software into user friendly tools for the rapid estimation of S/N for ultrasonic inspections of metals. This presentation provides an overview of the ongoing modeling effort, with emphasis on recent developments. The software can now treat both normal and oblique-incidence immersion inspections of curved metal components having equiaxed microstructures in which the grain size varies with depth. Both longitudinal and shear-wave inspections are treated. The model transducer can either be planar, spherically-focused, or bi-cylindrically-focused. A calibration (or reference) signal is required, and is used to deduce the measurement system efficiency function. This can be “invented” by the software using center frequency and bandwidth information specified by the user, or, alternatively, a measured calibration signal can be used. Defect types include flat-bottomed-hole (FBH) reference reflectors, and spherical pores and inclusions. Simulation outputs include estimated defect signal amplitudes, RMS grain noise amplitudes, and S/N ratios as functions of the depth of the defect within the metal component. At any particular depth, the user can view a simulated A-scan displaying the superimposed defect and grain-noise waveforms. The realistic grain noise signals used in the A-scans are generated from a set of measured “universal” noise signals whose strengths and spectral characteristics are altered to match predicted noise characteristics for the simulation at hand. Examples are presented comparing measured and predicted A-scan signals for FBHs in Nickel-alloy components. We also discuss efforts currently underway to generate a simulated C-scans (including grain noise speckle) corresponding to inspections in which the model transducer is scanned above the defect. As will be demonstrated as part of this poster presentation, the software typically requires only a few seconds to complete a simulation when running on a typical laptop computer

Long-Range Exciton Diffusion in Two-Dimensional Assemblies of Cesium Lead Bromide Perovskite Nanocrystals

F\"orster Resonant Energy Transfer (FRET)-mediated exciton diffusion through artificial nanoscale building block assemblies could be used as a new optoelectronic design element to transport energy. However, so far nanocrystal (NC) systems supported only diffusion length of 30 nm, which are too small to be useful in devices. Here, we demonstrate a FRET-mediated exciton diffusion length of 200 nm with 0.5 cm2/s diffusivity through an ordered, two-dimensional assembly of cesium lead bromide perovskite nanocrystals (PNC). Exciton diffusion was directly measured via steady-state and time-resolved photoluminescence (PL) microscopy, with physical modeling providing deeper insight into the transport process. This exceptionally efficient exciton transport is facilitated by PNCs high PL quantum yield, large absorption cross-section, and high polarizability, together with minimal energetic and geometric disorder of the assembly. This FRET-mediated exciton diffusion length matches perovskites optical absorption depth, opening the possibility to design new optoelectronic device architectures with improved performances, and providing insight into the high conversion efficiencies of PNC-based optoelectronic devices

py4DSTEM: a software package for multimodal analysis of four-dimensional scanning transmission electron microscopy datasets

Scanning transmission electron microscopy (STEM) allows for imaging, diffraction, and spectroscopy of materials on length scales ranging from microns to atoms. By using a high-speed, direct electron detector, it is now possible to record a full 2D image of the diffracted electron beam at each probe position, typically a 2D grid of probe positions. These 4D-STEM datasets are rich in information, including signatures of the local structure, orientation, deformation, electromagnetic fields and other sample-dependent properties. However, extracting this information requires complex analysis pipelines, from data wrangling to calibration to analysis to visualization, all while maintaining robustness against imaging distortions and artifacts. In this paper, we present py4DSTEM, an analysis toolkit for measuring material properties from 4D-STEM datasets, written in the Python language and released with an open source license. We describe the algorithmic steps for dataset calibration and various 4D-STEM property measurements in detail, and present results from several experimental datasets. We have also implemented a simple and universal file format appropriate for electron microscopy data in py4DSTEM, which uses the open source HDF5 standard. We hope this tool will benefit the research community, helps to move the developing standards for data and computational methods in electron microscopy, and invite the community to contribute to this ongoing, fully open-source project

SIR-HUXt—A particle filter data assimilation scheme for CME time-elongation profiles

We present SIR-HUXt, the integration of a sequential importance resampling data assimilation scheme with the HUXt solar wind model. SIR-HUXt assimilates the time-elongation profiles of Coronal Mass Ejection (CME) fronts in the low heliosphere, like those extracted from heliospheric imager (HI) data. Observing System Simulation Experiments are used to explore SIR-HUXt's performance for a simple synthetic CME scenario of an Earth directed CME in a uniform solar wind, where the CME is initialized with the average CME speed and width. These experiments are performed for a range of observer locations, from 20° to 90° behind Earth, spanning the L5 point where ESA's Vigil mission will return HI data for operational space weather forecasting. For this idealized scenario, SIR-HUXt performs well at constraining the CME speed, and has some success at constraining the CME longitude while the CME width is largely unconstrained by SIR-HUXt. Rank-histograms suggest the SIR-HUXt ensembles are well calibrated, with no indications of bias or under/over dispersion. Improved constraints on the initial CME speed lead to improvements in the CME transit time and arrival speed. For an L5 observer, SIR-HUXt reduced the transit time and arrival speed uncertainties by 69% and 63%. Therefore, SIR-HUXt could improve the real-world representivity of HUXt simulations and reduce the uncertainty of CME arrival time forecasts. The idealized scenario studied here likely enhances SIR-HUXt's performance relative to the challenge of simulating real-world CMEs and solar wind conditions. Future work should validate SIR-HUXt with case studies of real CMEs in structured solar wind