10,315 research outputs found
Capacitance transients in p-type GaAs MOS structures and application to lifetime mapping during solar cell fabrication
Fabrication on p-type GaAs of MOS structures in which the quality of the oxide is such that the surface can be driven into deep inversion by a voltage pulse is reported. The capacitance transients in such MOS capacitors as a function of step amplitude and temperature were measured and the transients were analyzed by an extension of a method for silicon. The oxides were produced by plasma oxidation on an LPE-grown p-type GaAs specimen with N sub A of 3x10 to the 17th power/cu cm. The capacitors were produced by depositing 50 microns-diameter gold dots over the native oxide and, therefore, the lifetime is localized to the area under the dot. The method permits extraction of both the bulk lifetime and the interface recombination velocity. These parameters on samples with different N sub A were measured and a correlation between tau sub g and N sub A was found
The Kirillov picture for the Wigner particle
We discuss the Kirillov method for massless Wigner particles, usually
(mis)named "continuous spin" or "infinite spin" particles. These appear in
Wigner's classification of the unitary representations of the Poincar\'e group,
labelled by elements of the enveloping algebra of the Poincar\'e Lie algebra.
Now, the coadjoint orbit procedure introduced by Kirillov is a prelude to
quantization. Here we exhibit for those particles the classical Casimir
functions on phase space, in parallel to quantum representation theory. A good
set of position coordinates are identified on the coadjoint orbits of the
Wigner particles; the stabilizer subgroups and the symplectic structures of
these orbits are also described.Comment: 19 pages; v2: updated to coincide with published versio
Mesothelioma and thymic tumors: Treatment challenges in (outside) a network setting
The management of patients with mesothelioma and thymic malignancy requires continuous multidisciplinary expertise at any step of the disease. A dramatic improvement in our knowledge has occurred in the last few years, through the development of databases, translational research programs, and clinical trials. Access to innovative strategies represents a major challenge, as there is a lack of funding for clinical research in rare cancers and their rarity precludes the design of robust clinical trials that could lead to specific approval of drugs. In this context, patient-centered initiatives, such as the establishment of dedicated networks, are warranted. International societies, such as IMIG (International Mesothelioma Interest Group) and ITMIG (International Thymic Malignancy Interest Group) provide infrastructure for global collaboration, and there are many advantages to having strong regional groups working on the same issues. There may be regional differences in risk factors, susceptibility, management and outcomes. The ability to address questions both regionally as well as globally is ideal to develop a full understanding of mesothelioma and thymic malignancies. In Europe, through the integration of national networks with EURACAN, the collaboration with academic societies and international groups, the development of networks in thoracic oncology provides multiplex integration of clinical care and research, ultimately ensuring equal access to high quality care to all patients, with the opportunity of conducting high level clinical and translational research projects
Monopole-based quantization: a programme
We describe a programme to quantize a particle in the field of a (three
dimensional) magnetic monopole using a Weyl system. We propose using the
mapping of position and momenta as operators on a quaternionic Hilbert module
following the work of Emch and Jadczyk.Comment: Contribution to the volume: Mathematical Physics and Field Theory,
Julio Abad, In Memoriam}, M. Asorey, J.V. Garcia Esteve, M.F. Ranada and J.
Sesma Editors, Prensas Universitaria de Zaragoza, (2009
Tandem 2.0: Image and Text Data Generation Application
First created as part of the Digital Humanities Praxis course in the spring of 2012 at the CUNY Graduate Center, Tandem explores the generation of datasets comprised of text and image data by leveraging Optical Character Recognition (OCR), Natural Language Processing (NLP) and Computer Vision (CV). This project builds upon that earlier work in a new programming framework. While other developers and digital humanities scholars have created similar tools specifically geared toward NLP (e.g. Voyant-Tools), as well as algorithms for image processing and feature extraction on the CV side, Tandem explores the process of developing a more robust and user-friendly web-based multimodal data generator using modern development processes with the intention of expanding the use of the tool among interested academics. Tandem functions as a full-stack JavaScript in-browser web application that allows a user to login, upload a corpus of image files for OCR, NLP, and CV based image processing to facilitate data generation. The corpora intended for this tool includes picture books, comics, and other types of image and text based manuscripts and is discussed in detail. Once images are processed, the application provides some key initial insights and data lightly visualized in a dashboard view for the user. As a research question, this project explores the viability of full-stack JavaScript application development for academic end products by looking at a variety of courses and literature that inspired the work alongside the documented process of development of the application and proposed future enhancements for the tool. For those interested in further research or development, the full codebase for this project is available for download
Effectiveness Of A Diabetic Ketoacidosis Prevention Intervention In Children With Type 1 Diabetes
Diabetic ketoacidosis (DKA) continues to be common in youth with type 1 diabetes (T1D), with up to 10% of patients reporting at least 1 DKA event annually. Since many of these events should be preventable, we developed a brief educational intervention that was easy to implement in a busy practice setting and tested its effectiveness in reducing emergency department (ED) usage. Subjects aged \u3e 13 years old or the parents of children aged \u3c= 13 were given a short pre-test about their knowledge of signs and symptoms of DKA and sick day management practices. They were then instructed on sick day management specific to their treatment modality (pump vs. injection). Finally, they were given a printed tool for sick day management. 244 subjects in our pediatric T1D clinic received the intervention as part of a regular office visit. 76 of these subjects were given a follow-up survey 6-12 months later. Subjects/parents scored higher on the post-test than the pre-test (61.6% vs. 55.0% correct; p=0.007). Subjects/parents also recognized more diabetes sick days (p=0.014) following the intervention and called the emergency line more frequently (p=0.032). Among all subjects, ED use was reduced to 0.13 from 0.22 visits per person-year (p=0.07). ED visits significantly decreased among subjects \u3e 13 years of age (0.10 per person-year after versus 0.21 per person-year prior; p=0.024). A short educational intervention and printed management tool is effective in improving sick-day and DKA knowledge, increasing utilization of diabetes emergency line consultations, and reducing ED visits, especially in teenagers
Towards pragmatic competence in communicative teaching: the question of experience vs. instruction in the L2 classroom
Traditionally, pragmatic aspects of the Spanish language are overlooked in the communicative classroom. Pragmatic competence is important because it may ultimately determine whether a successful communicative interaction takes place. Successful communication in language learning must not only address linguistic forms but also acknowledge language as a reflection of the socio-cultural norms of the L2 community. The research questions of this thesis explore the aspects of experience and instruction and their degree of influence as they relate to the development of pragmatic competence. This thesis reports on the results of a pedagogically-based, empirical study in which the researcher investigated the extent to which course level, study abroad, and pedagogical intervention facilitate the development of pragmatic competence of L2 learners when making a request in Spanish. Two main aspects of politeness, pronominal address forms and verbal forms, were examined to measure the learners’ level of pragmatic competence. Whether responses were pragmatically-appropriate were based on the responses of native speakers of Spanish. The results of this study reveal that learners who have more experience or exposure to the language, or explicit classroom instruction do not necessarily possess a higher degree of pragmatic competence than those who have not. These findings suggest that perhaps grammatical competence and pragmatic competence may develop separately and at differing rates. Further research and attention to the various factors surrounding pragmatic competence is necessary in the language educator’s goal to aid the student towards acquisition of overall communicative competence
THE CITY WALLS OF FLORENCE, A METHOD TO MANAGE INFORMATIONS OF A COMPLEX SYSTEM
Abstract. The city walls of Florence constitute a complex system: six circles and at least nine distinct phases of use and transformation, from the foundation of Florentia to Florence Capital, to contemporary adjustments. The DIDA, Department of Architecture of the University of Florence with the Municipality of Florence, has been carrying out since 2012 the FIMU project with the study of the various walls circuits and diachronic surveys of the surviving wall sections. The aim is to combine and harmonize the historical data with technical-scientific innovation, expressing its own vision of the relationship between the history of the city of Florence and the correct valorization of one of its important Landmark. Every citizen must be able to recognize in the traces of the past his belonging to a community, the results expected from this research are the realization of an informative-didactic and informative apparatus that will emphasize this important historical testimony of Florence and its transformations occurred over the centuries. Data acquisition, processing and visualization methods define this research as 'experimental' for the knowledge and evolution of a historic city that would contribute to elevating services for the technical scientific community and the citizen, to which data would become available currently 'raw' with the preparation of an apparatus based on a database through the 'Open Data' platform of the Municipality of Florence
Machine-learning nonstationary noise out of gravitational-wave detectors
Signal extraction out of background noise is a common challenge in high-precision physics experiments, where the measurement output is often a continuous data stream. To improve the signal-to-noise ratio of the detection, witness sensors are often used to independently measure background noises and subtract them from the main signal. If the noise coupling is linear and stationary, optimal techniques already exist and are routinely implemented in many experiments. However, when the noise coupling is nonstationary, linear techniques often fail or are suboptimal. Inspired by the properties of the background noise in gravitational wave detectors, this work develops a novel algorithm to efficiently characterize and remove nonstationary noise couplings, provided there exist witnesses of the noise source and of the modulation. In this work, the algorithm is described in its most general formulation, and its efficiency is demonstrated with examples from the data of the Advanced LIGO gravitational-wave observatory, where we could obtain an improvement of the detector gravitational-wave reach without introducing any bias on the source parameter estimation
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