49755 research outputs found
Sort by
‘No more for him the streams of sorrow pour’: Teaching Mourning, Critiquing Classics, and Alternative Epistemology in Phillis Wheatley’s Elegies
No full textPublished in 1773, Phillis Wheatley’s volume Poems on Various Subjects, Religious and Moral was one of the first publications by an African American writer. Enslaved at the time of publication, Wheatley’s poems are often read for their potential subversiveness or their engagement with classical texts. In recent years, scholarly interest in her funeral elegies, addressed to bereaved individuals, has experienced a resurgence. In this paper, I read Wheatley’s epyllion “Niobe in Distress for Her Children Slain by Apollo, from a View of the Painting of Mr. Richard Wilson” alongside her elegy “A Funeral Poem on the Death of C. E. an Infant of Twelve Months.” Through close readings of these two poems within the context of Wheatley’s volume, I argue that taken together, they present a coherent instructional program for how to grieve. Niobe represents the emotional, intuitive griever. In the elegies, through engagement with stylistic elements of didactic poetry, the poet gives instructions for how to perform grief instrumentally. Wheatley offers a coherent program for mourning that advocates for an instrumental rather than intuitive approach to grief, an approach that allows an individual to move forward rather than share Niobe’s fate of petrification
迈向跨国公司统一税收
No full textProtracted debates and negotiations have led to a new approach to taxation of multinationals: apportionment of their global profits based on their real presence in each country. A concerted initiative by willing states could implement this approach using standards now agreed, facilitated through the UN Framework Convention now under negotiation
The global minimum corporate tax: outcomes and options
No full textThis Perspective discusses the fiscal and economic impacts of the global minimum tax; currently being implemented by many countries around the world. The global minimum tax is expected to raise tax revenues, reduce profit-shifting, and allow jurisdictions to strike a better balance between supporting investment and mobilising domestic revenues
A Story of Anticipatory Hope: Rohingya Refugee Teachers’ Motivation to Teach in Cox’s Bazar, Bangladesh
No full textSince the Myanmar military’s 2017 campaign of ethnic cleansing, close to one million Muslim minority Rohingya from Rakhine State have resided in the refugee camps of Cox’s Bazar, Bangladesh. As of late 2024, over 6,000 learning facilities and nearly 10,000 teachers from refugee and host-community populations serve almost 400,000 Rohingya children and adolescents (ISCG, 2025). Education’s purpose in Cox’s Bazar is multifaceted due to the liminality of Rohingya displacement. It contributes to the protection of children’s rights and it creates a tentative sense of belonging via the Myanmar Curriculum and Burmese language, which are taught in anticipation of their desired but unlikely repatriation to Myanmar.
Amid global teacher shortages (UNESCO, 2024), United Nations agencies and international non-governmental organizations in settings like Cox’s Bazar attribute the conditions in which conflict- and crisis-affected teachers work to a ‘teacher motivation crisis’. In parallel, a ‘global learning crisis’ sees teachers deficit theorized by these same actors, who highlight teachers’ weak academic foundations, dated teaching methods, and need for urgent and intensive teacher professional development (World Bank, 2019). In both instances, teachers’ propensity to be ‘alternatively qualified’ (Kirk and Winthrop, 2007) and ‘transformative intellectuals’ (Pherali et al., 2019) is overlooked, rendering teachers as passive system inputs rather than agents of change.
To better understand this reality and its effects on Rohingya education, this study employed an explanatory sequential mixed-methods research design to explore the experiences and factors associated with Rohingya refugee teachers’ motivation to teach. A plethora of studies from high-income and stable contexts define teacher motivation and measure the influence of intrinsic and extrinsic factors. However, a dearth of evidence from refugee-hosting settings means our understanding of refugee teachers’ motivation to teach is based on anecdote more than empirical fact. My study in Cox’s Bazar finds that intrinsic factors like a sense of self-efficacy and agency and extrinsic factors like professional development and compensation are powerful motivators for refugee and host-community teachers alike. But the ‘anticipatory hope’ of repatriation, education’s perceived role in achieving this aim, and the empowering effect of teaching on Rohingya women’s identities in particular, underscore Rohingya refugee participants’ stronger motivation to teach than their Bangladeshi host-community peers, despite their untenable work and living conditions.
As suggested by the ‘impossible fiction’ of refugee teachers’ work (Adelman, 2019) and the ‘parameters of hope’ that refugee education can represent (Dryden-Peterson and Reddick, 2017), there are practical limits to what education in refugee settings can achieve. Building on this reality, in this study I present the concept of ‘anticipatory hope’ to affirm teaching’s fulfillment of purposive, normative, and instrumental functions such as the right to quality education, a vocation, and a livelihood. But for Rohingya refugees it also emphasizes the transformative function of teaching as an inherently human and political act: teaching helps reshape Rohingya identities and a tentative sense of belonging in Bangladesh and to Myanmar while laying groundwork for their repatriation, even if it never comes
Postural Control in Achilles Tendinopathy
No full textBackground:
Achilles tendinopathy (AT) is a common lower limb overuse pathology that results from excessive or insufficient mechanical loading. AT presents in 1.85 per 1000 of the adult population with up to a 27% recurrence rate. AT disrupts tissue morphology which alters mechanical load regulation and may also affect motor performance. The purpose of this study was to examine the relationship between AT morphology, motor performance, and function.
Methods:
APDM inertial sensors instrumented the modified Balance Error Scoring System (mBESS) and the modified Clinical Test of Sensory Interaction on Balance (CTSIB-M) to measure postural control. To manipulate AT strain, participants were tested unshod on a neutral sham orthosis, a 12 mm forefoot lift, and a 12 mm rearfoot lift. The Victorian Institute of Sport Assessment-Achilles and the Lower Extremity Functional Scale quantified function. A repeated measures ANOVA examined the interaction between variables.
Results:
Twenty-one participants (8 female, 13 male, mean age 35.5, SD 10.8 years) with AT were tested. mBESS postural control was different between involved and uninvolved limbs (p = .054), and between forefoot lift and rearfoot lift conditions (p = .053). CTSIB-M postural control was not different between participants with AT and control limbs (p = .534). Ankle range of motion was very strongly negatively correlated with postural control (p = .001).
Conclusion:
This study demonstrated a difference in unilateral postural control between involved and uninvolved limbs and between forefoot lift and rearfoot lift conditions. There was no difference in bilateral postural control between AT and control limbs
Expert Witness: Knowledge, Disciplinarity and Professionalism in 19th-Century Literature and Law
No full textThis dissertation studies selected English novels from the 19th century in conjunction with legal texts (cases, philosophy and history) centred on the expert witness. The objective of this study is to demonstrate that, over the long 19th century as knowledge and work were increasingly structured by disciplinarity and professionalisation, literature was engaged in a parallel project to the law that has gone largely unremarked.
This project is the production of a ‘knowledge of knowledges’: over the long 19th century, the legal discourse constructed an understanding of other discourses from its interrogation of, and its (limited and qualified) deference to, expert witnesses representing their specialised knowledges. This recognition by the master-discourse became a valuable form of legitimation and public as well as formal status; simultaneously, the account of these knowledges as apprehended by law, and arranged in its discursive form of ‘precedent,’ developed a composite picture of the vast and increasing variety of disciplines, and of their claims to monopoly and authority over their respective fields.
This dissertation argues that literature stands out from these other disciplines, first because the literary expert witness is a nearly undeveloped subject in law, secondly and more importantly because literary works embody a comparable project of depicting, analysing, and critiquing other discourses—including law—as well as literature itself. The novels analysed here indicate a rich repository of critical thinking about knowledge, disciplinarity, and professionalism that carries the potential for a counter-discourse to the hegemonic claims of law. Full development of this potential could support arguments for the autonomy of literature, and for artistic freedom of representation, built on the foundation of literature’s own, ‘native’ discourse of knowledge and expertise
Optimal Modulation and Air-core Inductor Design for High-Ripple Soft-Switching Inverters
No full textThree-phase converters play a critical role in the electrification of the energy used to power modern life. Improving the understanding and best operating practices for these converters provides benefits for electric vehicles and their chargers, distributed energy, and any sectors that are experiencing an increase in electricity demand and production. Techniques and novel components for improving the performance of bidirectional variable frequency soft-switching three-phase grid-tied inverters were explored. These techniques were then tested in hardware using oscilloscope and power analyzer measurements for performance verification.
Examination and improvement of variable frequency soft-switching techniques were conducted first for a capacitor neutral point connected three-phase converter. Losses were considered and zero voltage switching operating regions were explored. Simulations and experiments were conducted to test the regions and to increase the maximum processed power using these techniques. In excess of 20kW was processed using a single inverter. Two such inverters were then parallelized in two different ways in an effort to increase the power processed by a single system. A discretization and synchronization technique was developed for interleaving the current ripple of the two inverters when appropriate. The highest power and efficiency achieved were 50kW and over 99%, respectively, more than sufficient for high efficiency DC fast charging.
Next, a novel method was created for the generation of soft-switching frequencies for the more commonly used neutral-point isolated three-phase inverter. The method frames soft-switching as a convex optimization problem. This inverter, in contrast with the previous topology, was constrained to use a single switching frequency for all three phases. This constraint was exploited to simplify the devised quadratic program that was constructed to minimize the filter inductor current ripple, subject to zero-voltage switching constraints. Simplifications showed the problem has a closed form solution. The technique was shown to work across different space-vector modulation strategies that are used to generate the controlling duty cycles. As in the first topology, simulation and experimental results verified the performance of the novel soft-switching strategy up to 11kW. The new algorithm was able to operate in real time on the same microcontroller as was used for the neutral point connected topology.
During development, it was noted that the concurrence of high frequencies and high ripple currents necessary for the soft-switching techniques used in both topologies cause large, unpredictable losses in the magnetic cores of the filter inductors. To remedy this, the cored inductors were substituted by novel air-core inductors as drop-in replacements. Using the neutral point connected topology for experimental comparisons, these inductors were found to increase the system efficiency by more than 0.5% at rated power. The final inductor design has twice the volume but just two-thirds of the weight. An electromagnetic simulation study was conducted and experiments show that circuit operation was not disrupted by the change in inductor.
Finally, the increased volume required by the air-core inductor was compensated for by interweaving three of the inductors into a single novel power processing structure called the triaxial inductor. Two triaxial inductor designs were constructed by winding the three coils orthogonally to one another. One design remains as close as possible to the first air-core inductors while the other attempts to minimize the proximity losses. The triaxial inductors were characterized as magnetically independent while their volume was reduced by up to 3.3x compared to the first air-core inductor. A second magnetic field simulation was performed to better understand the more complicated rotating field. It was found that the majority of the efficiency savings from the individual air-core inductors were maintained when the triaxial inductor was used in the same neutral point connected circuit
Essays on the Political Economy of Supply-Side Counternarcotics
No full textWhen, how, and why does the state choose to crack down on some forms of crime or threats to its authority but not others? What are the downstream effects of these choices? This dissertation investigates these questions through an examination of the political economy of counternarcotics enforcement in Latin America, focusing on the uneven territorial application of drug laws and the consequences of this selective enforcement for state-building, political behavior, socioeconomic development, and crime and illicit economies more broadly.
The first paper studies the geographic distribution of coca eradication via aerial fumigation in Colombia. It shows that enforcement patterns reflect variation in influence by different non-state armed groups. Municipalities with greater historical violence by armed actors aligned with the state---paramilitary groups---were relatively protected from aerial eradication after the election of a hardline president. In contrast, areas with greater historical violence by armed actors in opposition to the state---guerrilla groups---were disproportionately targeted. These patterns suggest that state consolidation is shaped by political incentives, complicating traditional narratives of incremental state-building.
The second paper explores how exposure to aerial fumigation shapes electoral behavior in rural Colombia. It finds that this coercive form of enforcement generates political backlash. Citizens affected by fumigation interpret the state's actions as punitive and unjust, rather than legitimate or neutral, in part because of the dynamics discussed in the first paper. Even as this political backlash might have the potential to affect change, the influence of non-state armed actors over enforcement decisions inhibits democratic accountability. In this way, government enforcement strategies can deepen political alienation and erode trust in democratic institutions.
The third paper, co-authored with Elena Barham, expands the analysis to Peru in addition to Colombia, investigating how counternarcotics strategies reshape the industrial organization of illicit markets. Using highly fine-grained spatial and remotely sensed data as well as qualitative interviews, it shows how state pressure in one area can generate unintended consequences in others, transforming the economic and criminal landscapes. In Peru, manual eradication displaces criminal activity rather than eliminating when groups can adapt to new territories or other illicit industries. In Colombia, forced eradication and even voluntary crop substitution programs encourage diversification into other illicit sectors like illegal mining and logging
Experimental Studies into Next-Generation Wireless Technologies: Full-Duplex and Millimeter-Wave
No full textUnending growth in Internet traffic has placed extreme demands on the capabilities of wireless networks, which often provide the last-mile delivery of data to the user. This demand has been exacerbated by modern applications, such as video streaming, and wireless networks will be further pushed by future applications such as massive-scale Internet-of-Things deployments and augmented/virtual reality.
Such applications may require certain performance guarantees including multi-gigabit data rates, sub-millisecond latency, as well as exceptional reliability. It is therefore important to develop technologies that will enable next-generation wireless networks capable of meeting these requirements. In this thesis, we use an experimental approach to developing and evaluating several key technologies to enable next-generation wireless networks, including full-duplex (FD) wireless and millimeter-wave (mmWave) network deployment.
This thesis is composed of three parts. The first covers FD wireless, where we use three generations of custom RF self-interference (SI) canceller hardware to build FD radios capable of sending and receiving signals at the same time and on the same frequency channel. We designed and deployed a first-of-its-kind open-access FD networking testbed within the city-scale COSMOS testbed, using RF SI cancellers based on the principle of frequency-domain equalization. We use the testbed to demonstrate median throughput gains of 1.1-1.9x in realistic low-power networks with an FD-capable base station (BS) and varying numbers of FD-capable users, closely matching analytical results.
We then use a wideband RF SI canceller based on the principle of time-domain equalization to evaluate an automatic configuration algorithm based on an orthogonal matching pursuit and suitable for mobile applications where swift reconfiguration of the RF SI canceller is necessary. We use a narrowband, phase-and-amplitude based RF SI canceller to evaluate a novel digital SI cancellation (SIC) algorithm based on a weighted least-squares finite impulse response filter that achieves up to 8 dB better performance over an unweighted least-squares method when the radio first switches on. Lastly, we use the same narrowband canceller to prototype an FD jammer-receiver, capable of intercepting an adversarial signal of interest while simultaneously jamming the intended recipient.
The second part covers mmWave channel modeling. As the wireless spectrum grows increasingly congested at lower frequencies (<6 GHz), use of higher frequencies is necessary. However, higher frequencies experience significant path loss and are more severely blocked by buildings and other structures, making network deployments challenging. To gain better insight into factors affecting mmWave signal propagation and inform network deployments in dense urban environments, we conduct three large-scale measurement campaigns to study the mmWave wireless channel at 28 GHz in outdoor-to-outdoor (O-O) and outdoor-to-indoor (O-I) scenarios. We use the measurement data to develop models of path loss, environmental angular spread, and temporal stability. We show, amongst other results, gigabit data rates achievable for users over 100 m away from the BS even in visually NLOS conditions, as well as a 20 dB additional loss caused by low-emissivity glass panels used in typical modern buildings.
Lastly, the third part of this thesis covers a set of measurement studies used to characterize wireless coverage of the outdoors COSMOS testbed and spectrum usage within the testbed area. We developed a custom measurement setup using a laptop to receive 802.11a data packets transmitted from various COSMOS nodes and record the received signal power. These results have been published online along with the corresponding raw data, providing a rich dataset for urban signal propagation at 2.4 GHz. We also used a mobile 28 GHz phased array antenna module (PAAM) to study the interference characteristics on a mmWave radiometer used to measure temperature, using the collected data to develop spectrum consumption models (SCMs) designed to protect such meteorologic equipment from unexpected interference.
In this thesis, we make a number of experimental contributions to the fields of FD wireless and mmWave channel modeling, as well as the further deployment of the COSMOS testbed. We believe these contributions to be important for meeting the increasingly stringent performance requirements of next-generation wireless networks
Essays in Environmental and Climate Economics
No full textThis dissertation focuses on two aspects of environmental economics: (1) understanding the impacts of climate change on economic systems and individual decisions and (2) informing the design of environmental policies to foster adaptation to future climate risks.
It aims to provide evidence of both academic and policy interests, combining diverse sources of data---censuses and surveys, satellite imagery, climate projections---with modeling tools from the empirical industrial organization literature.
The first chapter, ? , explores one trade-off governments face when designing weather insurance policies. On the one hand, offering assistance to individuals and businesses to insure their assets and revenues against climate risk lowers the financial strains extreme weather events put on the economy. On the other hand, interventions in the insurance market may slow down the adoption of costly adaptation technologies and increase the climate vulnerability of the system in the future. I study this question in the U.S. Federal Crop Insurance Program context. This program regulates weather protection insurance and offers large premium subsidies to farmers. On average, farmers pay only 40% of the price of their insurance and subsidies add to between 5 and 10 billion dollars annually. I build and estimate a dynamic land use and crop insurance choice model under climate change to quantify the aggregate welfare impact of alternative subsidy schedules. I find that without climate change, the current insurance subsidy decreases welfare by 1.5 percent of the total output value. Moreover, by disincentivizing farmers' adaptation to climate change and increasing the agricultural system's exposure to weather shocks in the future, the status quo further decreases welfare by 1.3 percentage points. However, designing the subsidies to reflect the climate change dynamic and shifting risk patterns provides efficiency gains at no additional cost to the government, fosters adaptation to climate change, and decreases the volatility of agricultural output.
The second chapter, : , with Marco Tabellini and Charles Taylor, asks whether migrants select destination with climate similar to that of their origin and the consequences of climate mismatch. Using historical censuses, administrative data and death records, we document several novel findings. First, we show that climate strongly predicts the spatial distribution migrants: a one degree Celsius discrepancy between origin and destination reduces migration flows by 0.5-1.5%, an effect similar to that of a 1.5% wage increase at destination. These results hold across time, geography, and migrant groups and are not driven by the persistence of ethnic networks or other confounders. Additionally, using variation in the long-run change in average US climate from 1900 to 2019, we find evidence that migration increases between locations whose climate converged. We provide evidence for two complementary mechanisms: climate-specific human capital and climate as amenity.
Finally, we show that climate mismatch significantly affects migrants' welfare. We derive an instrument for climate mismatch building on work by Terry et al. (2024) and show that five additional degrees of climate mismatch result in a loss of 40 days of life for adults aged 65 and more and an increase in infant mortality rate by 25%. We calculate an individual-level mortality cost of a 1°C change in climate to be $5,250. These findings can inform the design of climate change adaptation policies, such as resettlement and “managed retreat” from climate change hotspots