1,064 research outputs found

    Quantum feedback for rapid state preparation in the presence of control imperfections

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    Quantum feedback control protocols can improve the operation of quantum devices. Here we examine the performance of a purification protocol when there are imperfections in the controls. The ideal feedback protocol produces an x-eigenstate from a mixed state in the minimum time, and is known as rapid state preparation. The imperfections we examine include time delays in the feedback loop, finite strength feedback, calibration errors and inefficient detection. We analyse these imperfections using the Wiseman-Milburn feedback master equation and related formalism. We find that the protocol is most sensitive to time delays in the feedback loop. For systems with slow dynamics, however, our analysis suggests that inefficient detection would be the bigger problem. We also show how system imperfections, such as dephasing and damping, can be included in a model via the feedback master equation.Full Tex

    Adapting authoritarianism: institutions and co-optation in Egypt and Syria

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    This PhD thesis compares Egypt and Syria’s authoritarian political systems. While the tendency in social science political research treats Egypt and Syria as similarly authoritarian, this research emphasizes differences between the two systems with special reference to institutions and co-optation. Rather than reducibly understanding Egypt and Syria as sharing similar histories, institutional arrangements, or ascribing to the oft-repeated convention that “Syria is Egypt but 10 years behind,” this thesis focuses on how events and individual histories shaped each states current institutional strengthens and weaknesses. Specifically, it explains the how varying institutional politicization or de-politicization affects each state’s capabilities for co-opting elite and non-elite individuals. Beginning with a theoretical framework that considers the limited utility of democratization and transition theoretical approaches, the work underscores the persistence and durability of authoritarianism. Chapter two details the politicized institutional divergence between Egypt and Syria that began in the 1970s. Chapter three and four examines how institutional politicization or de-politicization affects elite and non-elite individual co-optation in Egypt and Syria. Chapter five discusses the study’s general conclusions and theoretical implications. This thesis’s argument is that Egypt and Syria co-opt elites and non-elites differently because of the varying degrees of institutional politicization in each governance system. Rather than view one country as more politically developed than the other, this work argues that Syria’s political institutions are more politicized than their Egyptian counterparts. Syria’s political arena is, thus, described as politicized-patrimonialism. Syria’s politicized-patrimonial arena produces uneven co-optation of elites and non-elites as they are diffused through competing institutions. Conversely, the Egyptian political arena remains highly personalized as weak institutions and individuals are manipulated and molded according to the president’s ruling clique. This is referred to as personalized-patrimonialism. As a consequence, Egypt’s political establishment demonstrates more flexibility in ad hoc altering and adapting its arena depending on the emergence of crises. This study’s theoretical implications suggest that, contrary to modernization and democratization theory’s adage that institutions lead to a political development, politicized institutions within a patrimonial order actually hinder regime adaptation because consensus is harder to achieve and maintain. It is within this context that Egypt’s de-politicized institutional framework advantages its top political elite. In this reading of Egyptian and Syrian politics, Egypt’s personalized political arena is more adaptable than Syria’s. These conclusions do not indicate that political reform is a process underway in either state

    Effect of changes in testing parameters on the cost-effectiveness of two pooled test methods to classify infection status of animals in a herd

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    Monte Carlo simulation was used to determine optimal fecal pool sizes for identification of all Mycobacterium avium subsp. paratuberculosis (MAP)-infected cows in a dairy herd. Two pooling protocols were compared: a halving protocol involving a single retest of negative pools followed by halving of positive pools and a simple protocol involving single retest of negative pools but no halving of positive pools. For both protocols, all component samples in positive pools were then tested individually. In the simulations, the distributions of number of tests required to classify all individuals in an infected herd were generated for various combinations of prevalence (0.01, 0.05 and 0.1), herd size (300, 1000 and 3000), pool size (5, 10, 20 and 50) and test sensitivity (0.5–0.9). Test specificity was fixed at 1.0 because fecal culture for MAP yields no or rare false-positive results. Optimal performance was determined primarily on the basis of a comparison of the distributions of numbers of tests needed to detect MAP-infected cows using the Mann–Whitney U test statistic. Optimal pool size was independent of both herd size and test characteristics, regardless of protocol. When sensitivity was the same for each pool size, pool sizes of 20 and 10 performed best for both protocols for prevalences of 0.01 and 0.1, respectively, while for prevalences of 0.05, pool sizes of 10 and 20 were optimal for the simple and halving protocols, respectively. When sensitivity decreased with increasing pool size, the results changed for prevalences of 0.05 and 0.1 with pool sizes of 50 being optimal especially at a prevalence of 0.1. Overall, the halving protocol was more cost effective than the simple protocol especially at higher prevalences. For detection of MAP using fecal culture, we recommend use of the halving protocol and pool sizes of 10 or 20 when the prevalence is suspected to range from 0.01 to 0.1 and there is no expected loss of sensitivity with increasing pool size. If loss in sensitivity is expected and the prevalence is thought to be between 0.05 and 0.1, the halving protocol and a pool size of 50 is recommended. Our findings are broadly applicable to other infectious diseases under comparable testing conditions.ID: S0167587710000085; M3: Article; Accession Number: S0167587710000085; Author: Locksley L. McV. Messam (a, b); Author: Joshua M. O’Brien (c); Author: Sharon K. Hietala (d); Author: Ian A. Gardner (e, ⁎); Affiliation: St. Georges University, Department of Public Health and Preventive Medicine, School of Medicine, P.O. Box 7, True Blue, St. Georges, Grenada, West Indies; Affiliation: St. Georges University, Office of the Dean, School of Veterinary Medicine, P.O. Box 7, True Blue, St. George's, Grenada, West Indies; Affiliation: Center for Animal Disease Modeling and Surveillance, University of California, Davis, CA 95616, USA; Affiliation: California Animal Health and Food Safety Laboratory System, Davis, CA 95616, USA; Affiliation: Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; Keyword: Cost-effectiveness; Keyword: Pooled testing; Keyword: Mycobacterium avium subsp. paratuberculosis; Keyword: Retesting; Number of Pages: 11; Language: English

    Dressing up: Menswear in the Age of Social Media (2022): By Joshua Bluteau

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    "What does men's fashion say about contemporary masculinity? How do these notions operate in an increasingly digitized world? To answer these questions, author Joshua M. Bluteau combines theoretical analysis with vibrant narrative, exploring men's fashion in the online world of social media as well as the offline worlds of retail, production, and the catwalk. Is it time to reassess notions of masculinity? How do we construct ourselves in the online world, and what are the dangers of doing so? From the ateliers of London to the digital landscape of Instagram, Dressing Up re-examines the ways men dress, and the ways men post.

    Magnetic Property Measurements for Two Mixed Polytype Pyrrhotite Samples

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    Little to no curation was performed on this dataset. DRUM can not verify the completeness or quality of the documentation, nor the FAIRness of the included files. Please contact the author with any questions.Hobart, Kathryn K; Feinberg, Joshua M; Jones, Daniel S; Volk, Michael W R. (2022). Magnetic Property Measurements for Two Mixed Polytype Pyrrhotite Samples. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/227027

    Dressing Up:menswear in the age of social media

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    What does men’s fashion say about contemporary masculinity? How do these notions operate in an increasingly digitized world? To answer these questions, author Joshua M. Bluteau combines theoretical analysis with vibrant narrative, exploring men’s fashion in the online world of social media as well as the offline worlds of retail, production, and the catwalk. Is it time to reassess notions of masculinity? How do we construct ourselves in the online world, and what are the dangers of doing so? From the ateliers of London to the digital landscape of Instagram, Dressing Up re-examines the ways men dress, and the ways men pos

    Pinky : interactively analyzing large EEG datasets

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    Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 75-77).In this thesis, I describe a system I designed and implemented for interactively analyzing large electroencephalogram (EEG) datasets. Trained experts, known as encephalographers, analyze EEG data to determine if a patient has experienced an epileptic seizure. Since EEG analysis is time intensive for large datasets, there is a growing corpus of unanalyzed EEG data. Fast analysis is essential for building a set of example data of EEG results, allowing doctors to quickly classify the behavior of future EEG scans. My system aims to reduce the cost of analysis by providing near real-time interaction with the datasets. The system has three optimized layers handling the storage, computation, and visualization of the data. I evaluate the design choices for each layer and compare three dierent implementations across dierent workloads.by Joshua Blum.M. Eng

    C3H7NO2S effect on concrete steel-rebar corrosion in 0.5 M H2SO4 simulating industrial/microbial environment

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    This paper investigates C3H7NO2S (Cysteine) effect on the inhibition of reinforcing steel corrosion in concrete immersed in 0.5 M H2SO4, for simulating industrial/microbial environment. Different C3H7NO2S concentrations were admixed, in duplicates, in steel-reinforced concrete samples that were partially immersed in the acidic sulphate environment. Electrochemical monitoring techniques of open circuit potential, as per ASTM C876-91 R99, and corrosion rate, by linear polarization resistance, were then employed for studying anticorrosion effect in steel-reinforced concrete samples by the organic hydrocarbon admixture. Analyses of electrochemical test-data followed ASTM G16-95 R04 prescriptions including probability distribution modeling with significant testing by Kolmogorov-Smirnov and student's t-tests statistics. Results established that all datasets of corrosion potential distributed like the Normal, the Gumbel and the Weibull distributions but that only the Weibull model described all the corrosion rate datasets in the study, as per the Kolmogorov-Smirnov test-statistics. Results of the student's t-test showed that differences of corrosion test-data between duplicated samples with the same C3H7NO2S concentrations were not statistically significant. These results indicated that 0.06878 M C3H7NO2S exhibited optimal inhibition efficiency η = 90.52±1.29% on reinforcing steel corrosion in the concrete samples immersed in 0.5 M H2SO4, simulating industrial/microbial service-environment

    Design of a high quality factor spiral inductors in RF MCM-D

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    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 79-82).This thesis studies the design and fabrication of spiral inductors for use in Radio Frequency (RF) applications. A design methodology is developed to search an inductor design space efficiently using existing simulation software. The methodology allows designers to specify a desired inductance, total area, and frequency of operation instead of the geometrical parameters required by most design software. An implementation of the methodology that finds devices with optimal quality factor at a given frequency is presented. Several inductor designs are generated using this implementation, and the devices are fabricated in the Draper Laboratory, Inc. Multichip Module-Deposited (MCM-D) process. Simulated characteristics of the devices are verified using experimental measurements, and deviations from predicted performance are discussed.by Joshua Peters.M.Eng
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