Can the XY+Z Heisenberg Model Be Compressed Using the Yang-Baxter Equation? An Exploration of the Compression of Quantum Time Dynamic Circuits Describing Heisenberg Spin Chains

Quantum computing is currently deployed on noisy intermediate-scale quantum (NISQ) devices, which are only able to simulate circuits reliably on shallow depth quantum circuits. A promising problem on near-term quantum computers is quantum time dynamics (QTD). However, QTD circuits grow with increasing time simulations making them difficult to simulate on NISQ devices. This thesis project explores QTD simulations in variations of 1D Heisenberg spin chains with nearest-neighbor and transverse external field interactions with an eye towards studying the dynamics in broader classes of spin models. I first study the quantum Yang-Baxter equation (YBE) and how it has been shown to compress simulations of QTD of spin models without external magnetic fields and its relationship to the free fermion model. I then combine this research with similar attempts at compressing QTD simulations of spin models that include an external field like the XY+Z model. I find that the XY+Z model cannot be compressed and deployed on a NISQ device because the YBE cannot be performed on the model perfectly, however, a more generalized transverse field model can be compressed

Buoyancy-driven plumes in a layered porous medium

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Algorithms for Assessing Intervention Effects in Single-Case Studies

Free web-based resources or popular software to assess six data features recommended by the What Works Clearinghouse: Procedures and Standards Handbook (IES, 2013 February) to determine intervention effects in a single-case study (Lambert, Cartledge, Heward, & Lo, 2006) are demonstrated. Lambert et al. (2006) employed a reversal (or ABAB) design and visual inspection to investigate the effectiveness of the report-card treatment in reducing disruptive behaviors in students. In our demonstration, we assessed each of the six data features separately; then integrated six assessments into one comprehensive analysis of the intervention effect. A simple approach to the determination of intervention effects illustrates how researchers and practitioners can be empowered to interpret data comprehensively and formulate evidence-based conclusions logically from well-designed and well-executed single-case studies

Reduce Nb3Sn Strand Deformation when Fabricating High Jc Rutherford Cables

During Phase I, our efforts were to reduce subelements deformation when fabricating Nb3Sn Rutherford cables. Our first focus is on 217-sublement tube type strand. We successfully made a few billets in ÃÂþâÃÂàOD tube with different Cu spacing between subelements, and supplied the strands to Fermi Lab for cabling. Through the rolling test characterization, these types of strands did not have enough bonding between subelements to withstand the deformation. We saw copper cracking between subelements in the deformed strands. We scaled up the billet from ÃÂþâÃÂàOD to 1.5âÃÂàOD, and made two billets. This greatly improves the bonding. There is no copper cracking in the deformed strands when we scaled up the diameter of the billets. Fermi Lab successfully made cables using one of this improved strands. In their cables, no Cu cracking and no filament bridging occurred. We also successfully made a couple of billets with hex OD and round ID subelements for 61-subelement restack. Due to the lack of bonding, we could not judge its cabling property properly. But we know through this experiment, we could keep the Nb round, once we select the proper Cu spacing

Increasing the Jc of Tube-Type Nb3Sn Strands

In this Phase I, we successfully made strands with better Cu/Sn ratio to reduce the coarse Nb3Sn grain region, thereby providing the potential of increasing the non-Cu Jc in the Phase II and scaling up to 2âÃÂàbillets with 331 subelements. In order to improve the strandâÃÂÃÂs high field properties, we successfully doped low amount of Ti in the subelements and made a 217-subelement wire which has been drawn down to 0.7 mm without any breakage. This strand gave subelement size of 35 ÃÂõm. We will scale up the Ti-doped billet to 271-subelement in 1.5âÃÂàbillet in this proposed Phase II. The hexagonal shaped subelements with round Nb-Sn have been developed for a 61-subelement restack. Thus the results indicated that for 217-subelement restack in a 2âÃÂàbillet we have the potential to draw down this type of construction without problems while maintaining a good array to react more Nb to get higher non-Cu Jc in the Phase II

Magnetoelectric coupling induced by interfacial orbital reconstruction

The magnetoelectric coupling effect with profound physics and enormous potential applications has provoked a great number of research activities in materials science. Here, we report that the reversible orbital reconstruction driven by ferroelectric polarization modulates the magnetic performance of ferroelectric ferromagnetic heterostructure. Mn in plane orbital occupancy and related interfacial exotic magnetic state are enhanced and weakened by the negative and positive electric field, respectively. Our findings thus not only present a broad opportunity to fill the missing member, orbital in the mechanism of magnetoelectric coupling, but also make the orbital degree of freedom straight forward to the application in microelectronic device.Comment: 26 pages, 5 figures, Accepted by Advanced Material

Diminished temperature and vegetation seasonality over northern high latitudes

Global temperature is increasing, especially over northern lands (>50° N), owing to positive feedbacks1. As this increase is most pronounced in winter, temperature seasonality (ST)—conventionally defined as the difference between summer and winter temperatures—is diminishing over time2, a phenomenon that is analogous to its equatorward decline at an annual scale. The initiation, termination and performance of vegetation photosynthetic activity are tied to threshold temperatures3. Trends in the timing of these thresholds and cumulative temperatures above them may alter vegetation productivity, or modify vegetation seasonality (SV), over time. The relationship between ST and SV is critically examined here with newly improved ground and satellite data sets. The observed diminishment of ST and SV is equivalent to 4° and 7° (5° and 6°) latitudinal shift equatorward during the past 30 years in the Arctic (boreal) region. Analysis of simulations from 17 state-of-the-art climate models4 indicates an additional STdiminishment equivalent to a 20° equatorward shift could occur this century. How SV will change in response to such large projected ST declines and the impact this will have on ecosystem services5 are not well understood. Hence the need for continued monitoring6 of northern lands as their seasonal temperature profiles evolve to resemble thosefurther south.Lopullinen vertaisarvioitu käsikirjoitu

Deep learning in ophthalmology: The technical and clinical considerations

The advent of computer graphic processing units, improvement in mathematical models and availability of big data has allowed artificial intelligence (AI) using machine learning (ML) and deep learning (DL) techniques to achieve robust performance for broad applications in social-media, the internet of things, the automotive industry and healthcare. DL systems in particular provide improved capability in image, speech and motion recognition as well as in natural language processing. In medicine, significant progress of AI and DL systems has been demonstrated in image-centric specialties such as radiology, dermatology, pathology and ophthalmology. New studies, including pre-registered prospective clinical trials, have shown DL systems are accurate and effective in detecting diabetic retinopathy (DR), glaucoma, age-related macular degeneration (AMD), retinopathy of prematurity, refractive error and in identifying cardiovascular risk factors and diseases, from digital fundus photographs. There is also increasing attention on the use of AI and DL systems in identifying disease features, progression and treatment response for retinal diseases such as neovascular AMD and diabetic macular edema using optical coherence tomography (OCT). Additionally, the application of ML to visual fields may be useful in detecting glaucoma progression. There are limited studies that incorporate clinical data including electronic health records, in AL and DL algorithms, and no prospective studies to demonstrate that AI and DL algorithms can predict the development of clinical eye disease. This article describes global eye disease burden, unmet needs and common conditions of public health importance for which AI and DL systems may be applicable. Technical and clinical aspects to build a DL system to address those needs, and the potential challenges for clinical adoption are discussed. AI, ML and DL will likely play a crucial role in clinical ophthalmology practice, with implications for screening, diagnosis and follow up of the major causes of vision impairment in the setting of ageing populations globally