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Space and Spatial Formation of Subjectivity in Five Women Writers’ City Writings
No full textThis dissertation is a study of space and spatial formation of subjectivity in five renowned
women writers’ city writings: Virginia Woolf’s Mrs. Dalloway, Jean Rhys’s Voyage in the Dark,
Nella Larsen’s Passing, Anzia Yezierska’s Salome of the Tenements, and Eileen Chang’s
Chuanqi (Legends). Taking space as a point of departure, I engage in a close reading of the
selected novels and argue that the city with its concrete streets and buildings does not simply
serve as settings for their literary creations but is endowed with a constellation of conceptual
forces under which the characters must negotiate between their internal selves and external social
identities so as to form their subjectivities. As a result of this negotiation under combined forces,
one’s subjectivity formation is registered within and defined by the city space. While the
formation of subjectivity is often studied in terms of language, which constructs an individual’s
subjectivity in accordance with the social and cultural discourses, my dissertation shifts the arch
question in subjectivity formation from “who I am” to “where I am” and conducts an
examination of the dynamic relationship between space and self in the literary representations of
several modern metropolises, including the post-war London, roaring New York, colonial Hong
Kong, and semi-colonial Shanghai in the first half of the twentieth century. My central argument
is that space plays a constitutive role in the formation and transformation of self, identity, and
subjectivity among the five women writers’ city writings. Specifically, Woolf’s city street gives
rise to a street-consciousness that breeds a dispersed self in resistance to state’s spatial
interpellation; Rhys’s city accommodation addresses the formation of a displaced self within a
rented space which operates culturally, physically, and psychologically; Larsen’s depiction of the
spatial movement between up and down reveals the self-divided subjectivity shaped by one’s
racial passing; Yezierska’s portrayal of the movement through the urban ghetto traces the
formation of a self-fashioned subjectivity; Chang’s location of the uncanny spaces within the
semi-colonial Shanghai and colonial Hong Kong captures the liminal subjectivity among the
Chinese urbanites. Moreover, my dissertation also argues that these novels highlight the way in
which characters’ experiences of the spaces they occupy shape their sense of self and
subjectivity, which in turn changes their perceptions of the spaces around them. Thus, by
analyzing how one constructs and reconstructs one’s subjectivity through spatial changes in
historically specific and culturally different metropolises imaginatively mapped by Woolf, Rhys,
Larsen, Yezierska, and Chang, this dissertation has uncovered a neglected dimension of the five
women writers’ fictional works: the formulative as well as transformative impact of space upon
the process of subjectivity formation. It offers a new perspective on the representation of city
space in addition to those of gender, race, and class in our understanding of who we are and why
we are what we are in modern times
A Transdisciplinary Framework to Analyze Interactive and Participatory Experiences in Public Settings
No full textThis dissertation presents a transdisciplinary framework to analyze interactive and participatory
experiences in public settings. This type of experience is constructed through the use of different
media and technological devices and installed in spaces designed for collective or communal use.
This work draws on the fields of Public Interactives and Art as Social Practice, and uses methods
of field research, design research, creative practice, and reflective practice to create a framework
of analysis. Four different types of cultural institutions and two specific interactive or
participatory experiences of each are explored in four case studies. The framework of analysis
addresses research questions concerning Space, Publics, and Experience. Specifically, the
analyses presented explore the entangled infrastructures of each institution and how they
influence the interactive experience. Each chapter also examines how each of the studied
institutions form and communicate their preferred publics, and how the experiences offered
through interactive installations are used to engage visitors as the preferred publics of the
institution. To analyze matters of experience, the framework presents the concept of the
mediated experience, as the experience that is on offer in a space as a visitor encounters it, and of
scripting, as the linear timeline or storyboard of each moment of the experience as it is offered to
participants. The research findings of this transdisciplinary study provide a new perspective to
the analysis of interactive and participatory experiences in public settings, particularly in cultural
institutions. The research also contributes insights to designers and creative practitioners of
interactive and participatory experiences in public settings, as it offers new layers of
understanding towards a more intentional practice
Differential Ion Motion in Perovskite Light Emitting Electrochemical Cells
No full textPerovskite light emitting diodes (PeLED) have shown promising progress as next-generation
efficient electroluminescent devices. However, PeLEDs suffer from low lifetimes and color
instability during operation that limits its insertion into most practical applications. To address this
concern, I investigated a form of perovskite light-emitting device termed perovskite light-emitting
electrochemical cells (PeLECs) that utilize a phenomenon of selective differential ion motion in
perovskite devices. I have been exploring an interesting phenomenon of “differential ion motion”
in PeLECs, where under applied bias, additive ions (LiPF6) selectively move while restricting the
motion of intrinsic perovskite ions. This interplay of intrinsic and additive ions enhances the
efficiency and operational stability of PeLECs. In differential ion motion, the perovskite structure
remains stable while sacrificial additive ions move in response to the applied electric field. These
additive ions accumulate at respective electrodes (anions at anode and cations at the cathode) and
improve electronic charge injection (electron and holes) by the formation of electrical double
layers (EDLs) at the electrode interfaces.
Specifically, I fabricated and characterized PeLECs, directly measuring their luminance-currentvoltage characteristics, quantum efficiency, power efficiency, electroluminescence (EL) spectra,
operational stability. To understand the fundamental materials science behind device performance,
I have performed numerous materials and device characterizations such as electron microscopy
(SEM, TEM), spectroscopy (XPS, UV-Vis), crystallography (XRD), force microscopy (AFM),
reliability testing, electrochemical circuit design, and photoluminescence (PL) spectra, lifetime,
and quantum yield.
We demonstrated that optimized Li salt additive improves thin film morphology, increases PL
stability and quantum yield, reduces charge traps, and strengthens the perovskite chemical
bonding. Then, we hypothesized differential ion motion phenomenon and showed long lifetimes
at constant current, calculated EDLs thickness by using electrochemical impedance circuit model.
We also demonstrated voltage-controlled color-tunable perovskite host-ionic guest (Ir-ionic
transition metal complex) LECs. We observed the benefits of differential ion motion in pure blue
light-emitting mixed-halide perovskite, where we effectively suppressed detrimental halide
segregation under intense photoexcitation and electrical bias that facilitated us to obtain longawaited stable blue PeLECs satisfying technological emission standards. Additionally, we
integrated highly emissive zero-dimensional perovskite into a 3D perovskite matrix through a
novel solvent engineering method that demonstrated high quantum efficiency and operational
stability facilitated by differential ion motion.
PeLECs have shown superior operational stability (initial luminance level of 3200 cd/m2, 120 h—
extrapolates to 30,000 h half-life at 100 cd/m2, the common industrial benchmark for a lifetime)
and high color-purity (Full-width half maximum of EL spectra ≤ 18 nm). Pure Blue emission from
PeLECs meets all the National Television System Committee (NTSC) requirements. These
PeLECs are simple single-layer devices that offer ease of processing (low-temperature and costeffective) for facile fabrication of large-area display and lighting applications. Leveraging
differential ion motion in PeLECs demonstrates a new pathway of utilizing simple and smart,
wearable devices for the internet of things (IoT) for digital communication and fashion
Control and Diagnosis of Permanent Magnet Motors
No full textPermanent magnet synchronous machines (PMSMs) have been deployed widely in recent years
due to their inherent features such as high efficiency and high power density. Thanks to these
merits, they are used in various applications including renewable systems, transportation, and
automation systems to name a few. Considering the safety, reliability and system efficiency,
these systems should be monitored and maintained carefully to avoid accidents or operation
losses. Therefore, developing reliable fault diagnosis and post-fault control tools is essential.
To design high performance fault diagnosis and post-fault-control algorithms, drive system
requires accurate electrical parameter information and highly precise current and voltage
feedback measurement. This dissertation presents a comprehensive monitoring and diagnosis
techniques for inter-turn short-circuit (ITSC) fault which can accurately estimate short circuit
current based on well calculated motor parameters and compensated feedback signals.
Inductances are crucial parameters for electric motors. It is essential to obtain accurate
electrical parameter information of a permanent magnet synchronous machines (PMSM) for
high performance controller and observer design. Due to the saturation of magnetic elements,
the inductances of permanent magnet motors change depending on the operating points. To
solve this problem, the inductance model is analyzed carefully and an improved absolute
inductance estimation is proposed based on high-frequency current signal injection.
Secondly, the compensation of feedback current signal in drive system is studied. To obtain
highly accurate current signal, sigma delta ADCs (SD-ADCs) are used to improve sensing
resolution and signal-to-noise ratio. However, the additional latency caused by the use of
digital SINC filters for demodulation becomes remarkable and degrades the performance of
dynamic systems. The effects of latency on the system bandwidth and gain/phase are analyzed
in detail and a Kalman filter-based latency compensation algorithm and compensation
strategies are proposed.
In the last of the research, a comprehensive analysis for ITSC online short circuit current
estimation is proposed. By analyzing the voltage harmonics caused by ITSC fault under
stationary and rotating reference frame, the relationship between voltage harmonics, short
circuit current and reference voltage is established. According to this relationship, a harmonic
analysis-based online short circuit estimation method is proposed. Then the proposed
short circuit estimation technique is adopted for PMSM healthy condition monitoring and
post-fault-control algorithm design
Multi-channel Acoustic Signal Processing on Edge Devices
No full textMicrophone arrays are useful in determining the space-time structure of an acoustic field. They are widely employed in many popular acoustic signal processing applications, including speech enhancement, speech separation, sound source localization, and sound source tracking. This dissertation introduces a set of practical and efficient multi-channel acoustic signal processing algorithms specifically targeted for improving people's spatial awareness and hearing towards sources of interest using edge devices featuring a microphone array. Such devices include smartphones, smart glasses, and hearing aids. As proof of feasibility, the majority of the developed algorithms have been in fact deployed as mobile applications for smartphones. First, Directional Signal Extraction Network (DSENet) is proposed. DSENet is a real-time, computationally-and-memory-efficient neural network which extracts a signal source located within a predefined directional region of interest. Experimental results show that DSENet is capable of outperforming oracle beamformers and state-of-the-art (SOTA) networks in low-latency causal speech separation while incurring a system latency of only 4 ms. Second, a complete method for highly accurate and efficient real-time estimation of 2-dimensional direction of arrival (2D-DOA) using a nonlinear 3-microphone array is presented. The proposed method provides the ability to estimate and track azimuth and elevation angles of one or more acoustic sources in real-time. Third, in an attempt to increase the number of microphones for improved acoustic processing performance, a distributed, real-time, low-latency audio input/output (I/O) framework for mobile devices is proposed. This framework can simulate an irregular and flexible microphone array by wirelessly synchronizing and processing multi-channel audio input of multiple mobile devices into real-time output. Fourth, a method for jointly calibrating and synchronizing two arrays of microphones and loudspeakers is described. This method allows finding the clock offset between two devices featuring an array of microphones and loudspeakers, as well as estimating their exact relative positions. Fifth, Delay-Filter-and-Sum Network (DFSNet) is proposed. DFSNet is a steerable neural beamformer invariant to microphone number and array geometry for real-time, low-latency speech enhancement. Apart from low latency, DFSNet is designed to incur controllable distortion and low memory and computational complexities, making it especially suitable for hearing aid applications. Comparison with SOTA reveals high performance approaching noncausal methods
Human Hydration Monitoring
No full textChronic dehydration is the usual state at which most people keep their bodies through their entire
lives. Dehydration states lead to many unnoticed detrimental health issues that can end up reducing
the life quality of entire societies. Water is the most important nutrient of human life, and because
of this it is important to monitor it. To my present knowledge, currently there are no commercial
wearable dehydration monitors that could help the public in keeping well hydrated and healthy.
This is the reason why finding a low-cost way to design a dehydration sensor system in a wearable
format is of paramount importance. In this work, the basis for the design of a hydration monitor
are established, and this could lead in the future, to a wearable device that consumers could reach
to so as to keep their hydration status well screened. In order to achieve such goal, multiple sensors
were designed, simulated using Finite Element Analysis (FEA) software, fabricated in The
University of Texas at Dallas Cleanroom, tested in-vitro, and those that performed best were tested
in Human Trials. Moreover, a custom Analog Front End linked to a microcontroller was designed
and fabricated to interface the sensors and provide measurement readings
Comparing Auditory and Written Word Learning in School-aged Children and Adolescents, and Identifying Factors That Contribute to Success
No full textThe purpose of this study was to examine developmental differences in children’s ability to
deduce the meaning of unknown words from the surrounding linguistic context in the auditory
and written modalities, and to identify the most important predictors of success in each modality.
Eighty-nine children ages 8-15 either read or listened to a narrative that included eight novel
words, with five exposures to each novel word. After the story, they participated in three posttests to assess how many word meanings they were able to deduce from the context of the story.
Results showed higher scores in the written modality than in the auditory modality. A relative
weights analysis revealed that age, vocabulary, and working memory were the most important
predictors of success in the word meaning deduction tasks regardless of modality. Surprisingly,
reading comprehension did not greatly influence success in the written modality, and language
comprehension did not greatly influence success in the auditory modality. This study provides
evidence that the written modality provides better support for novel word learning for children
with larger vocabularies and better working memory abilities
Development of Probe-based Devices and Methods for Applications in Micro/Nano Characterization and Fabrication
No full textThe ability to investigate mechanical and material properties of micro- and nano-sized devices
and surfaces is of significance in many fields of science and technology. Scanning tunneling microscope (STM), atomic force microscope (AFM), and MEMS force sensors are in high demand
for this purpose, whereas their functionality is limited in many cases. This dissertation focuses
on novel scanning methods, MEMS devices, and control design methodologies that facilitate micro/nano characterization and fabrication of devices and surfaces.
High-speed and high resolution scanning tunneling spectroscopy (STS), as well as atomically precise fabrication of silicon quantum electronic devices are still among challenging topics in the
STM. It is due to the limitation of conventional methods that are used for these purposes. Besides
the STM hardware specifications, control methods contribute significantly to achieving the ultimate goal of ultrafast STS and atomically precise manufacturing (APM). The STM control system
needs to be improved to harness the STS full potential, as well as to provide adequate precision
and robustness during lithography. In part I of this dissertation, we detail our research on the
STM-based probe microscopy for applications in surface characterization and atomically precise
manufacturing.
Modulation technique is conventionally used to obtain dnI/dV n STS images of a surface. However, images that are obtained from this method suffer from noise, which is mainly due to the
small amplitude of the modulation voltage. The modulation technique is a powerful tool which
enables us to utilize the unused frequency band of the STM for other purposes without disturbing
its normal operation. We exploit this technique in different STS and APM methods throughout the
part I of this dissertation. First, we propose a modified STM feedback loop to improve the SNR of
STS images. Then, a novel STM imaging mode is introduced, which is based on keeping dI/dV
constant. We also propose an ultrafast STS method that can provide an I–V curve for every pixel
of the image simultaneously with the topography image. This method significantly reduces the
spectroscopy time. Finally, we introduce a method for hydrogen depassivation lithography (HDL)
with STM. Unlike the conventional approach, where a positive bias voltage is applied to the sample, we have developed an automated scheme to perform HDL at negative bias voltages. We show
that our proposed lithography method significantly decreases chance of a tip-sample crash and can
potentially increase the lithography precision.
Probe-based force measurement systems are also widely utilized to investigate characteristics of
micro- and nano-sized devices and surfaces. These systems work based on measuring the interaction forces between a known probe and an unknown surface. In part II of this dissertation, we
proceed by proposing novel design and control methods for two well-known probe-based force
measurement systems: AFM and MEMS force sensor.
AFM plays a crucial role in a myriad of applications in science and technology. It is the most
widely used tool for imaging and manipulating matter at the nanoscale. The AFM utilizes a microcantilever with a very sharp tip that interacts with a sample surface. The use of this technology
alone does not guarantee its efficient functionality. It is of significant importance to harness the
full functionality of an AFM by employing efficient control methods. We implement a positive
position feedback controller on a previously designed active microcantilever (Coskun et al., 2017)
to achieve a faster cantilever response. Then, we exploit MEMS technology to realize an on-chip
MEMS AFM. The tracking performance of the device is enhanced by implementing different control methods. Finally, we propose a MEMS-based force sensor. On the contrary to the AFM
that mainly relies on its microcantilever for force measurements, a variety of mechanisms can be
incorporated in a MEMS force sensor. This makes it possible to readily adjust the force sensor
parameters. Our force sensor features built-in electrostatic actuation, piezoresistive displacement
sensor, and stiffness adjustment mechanism. It works in the closed-loop, which mitigates the adverse effect of flexural nonlinearities on the precision of the force measurement
Tractatus Exilium: the Subject of Exile and the Problem of Being: an Examination of the Work of Edmond Jabès and EM Cioran
No full textIn the simplest terms: What is exile? This work explores exile through an examination of the
writing of E.M. Cioran and Edmond Jabès. The twentieth century was notably a time of great
violence—the use of nuclear weapons, world wars, and the most terrible murder of millions of
Jews during the Shoah. The violence forced thinking people to reconsider the problem of
existence. Camus, Ionesco, and Beckett seemed to best express what it means to be human—
loneliness, fear, and despair—while Sartre, Levinas, and Heidegger responded as philosophers to
the disaster they saw everywhere. Questions of being again came to the fore with Heidegger’s
most important: What is the meaning of being? Edmond Jabès and E.M. Cioran, somewhat
obscure exiled writers in Paris, responded with their own brand of philosophy, what we may
refer to as Existential Mysticism. The aphorist and the philosopher seemed to develop an outline
for a twenty-first century mysticism based on the premise that to be born is to be in exile. While
exile is often explored as a political or historical phenomenon, even as an exception, here exile is
problematized as an existential and ontological question: Exile is a mode of being in the world.
Bound up in Jabès’s and Cioran’s experience of exile as absence were questions of being. Of the absence experienced in exile by Jabès, he unfolds in The Book of Questions—while the same
absence for Cioran emerges in his paragraphs, maxims, and aphorisms as the nothingness of
exile. In this nothingness are their experiences of exile and being. As two of the most celebrated
twentieth century French writers, it is impossible to understand their work without understanding
the influence of exile on their thinking. It was quintessentially the experience of absence and
nothingness, which becomes for them the mechanism for a deep exploration of being. Cioran and
Jabès ask questions of nothingness and of exile exploring exile more as philosophers than as a
poet and an aphorist. They come to similar conclusions while exiled to Paris. Every birth is an
expulsion—an exile of sorts. To exist is to have left our homeland—nothingness
Geometric Integrators for Non-separable Hamiltonian Systems
No full textIn this thesis, we consider non-separable Hamiltonian systems, and we develop an integrator
that combines Pihajoki’s expanded approach to phase space with the symmetric projection
technique. Through this, we construct a semiexplicit numerical integrator, meaning that the
primary time evolution step is explicit but the symmetric projection step is implicit. The
symmetric projection fixes the major disadvantage of the extended phase space technique by
binding possibly divergent copies of solutions. In addition, our semiexplicit approach gives
the first extended phase space integrator that is symplectic in the original phase space. This
is in contrast to those explicit extended phase space integrators of Pihajoki and Tao, which
are symplectic only in the extended phase space. Our integrator tends to preserve invariants
better than Tao’s. Moreover, for some higher-order implementations and higher-dimensional
problems, ours is faster than Tao’s explicit method despite being partially implicit