4,462 research outputs found

    Static deformations from point forces and force couples located in welded elastic Poissonian half-spaces: Implications for seismic moment tensors

    Get PDF
    We present analytic expressions for the static deformations produced by point forces and point force couples embedded in two elastic Poissonian half-spaces that are welded on a horizontal interface. We show that the deformations from point forces and from vertically dipping strike-slip point double couples vary continuously (except at the strike-slip source) as the source is moved across the welded interface. We show that the pattern of deformations from vertically dipping (or horizontally dipping) dip-slip point double couples also vary continuously as the source is moved across the welded interface, but the amplitude of the deformations jumps by the ratio of the rigidities. Finally, we show that the pattern of deformation from a point explosion source or from a point double-couple source dipping at angles other than 0Ā° or 90Ā° jumps as the source is moved across the boundary. We demonstrate that integration of point double-couple sources on a plane of finite extent mimics the deformation of slip on a fault plane where the total moment of the double-couples is Ī¼AD. We also demonstrate that deformations from a distribution of double couples on a horizontally dipping finite plane just above the interface are indistinguishable from the deformations produced by a similar distribution of double couples located just below the interface but with a total moment that is different by the ratio of the rigidities. This demonstrates that the moment of a dislocation that occurs between two materials is ambiguously defined. We discuss reasons why seismic moment is not a very satisfying way to parameterize the size of an earthquake. We show that potency, defined to be the integral of the slip over the rupture surface, is a more natural size scaling parameter than seismic moment

    Examining the Lived Experiences of Undergraduate Transgender Students at Four Year Institutions in the South

    Get PDF
    This qualitative, narrative study examined the lived experiences of transgender students at four-year institutions in the South. The college transition process and academic and social integration for transgender students was explored through the frameworks of Transition Theory (Schlossberg, 1995), Minority Stress Theory (Meyer, 1995; Breslow, Brewster, Velez, Wong, Geiger, & Soderstrom, 2015), and Academic and Social Integration theories (Tinto, 1975; Braxton, Hirschy, & McClendon, 2004). College climates can be challenging for transgender students, especially when campus staff and faculty are not prepared and/or aware of transgender studentsā€™ needs (Pryor, 2015). How students perceive their academic and social integration as well as how their integration was influenced by their gender identity was a key component of this study. Through a four-phase data collection process, transgender students had the opportunity to tell, share, and reflect on their experiences as transgender undergraduate students navigating the college transition, academic, and social integration processes. Through data collection and analysis, four categories emerged from participant responses: 1) Navigating Identity, 2) College Transition and Challenges, 3) Environment, Space, and Climate, and 4) Sympathizing with Others. Within each category, several sub-categories were identified as well. Institutions of higher education must recognize the ever-growing presence of transgender students on their campuses. Moreover, institutions have the opportunity and responsibility to create policies, spaces, and opportunities that allow transgender college students to have a supportive academic and social integration process

    Real-time testing of the on-site warning algorithm in southern California and its performance during the July 29 2008 M_w5.4 Chino Hills earthquake

    Get PDF
    The real-time performance of the Ļ„_c -P_d on-site early warning algorithm currently is being tested within the California Integrated Seismic Network (CISN). Since January 2007, the algorithm has detected 58 local earthquakes in southern California and Baja with moment magnitudes of 3.0 ā‰¤ M_w ā‰¤ 5.4. Combined with newly derived station corrections the algorithm allowed for rapid determination of moment magnitudes and Modified Mercalli Intensity (MMI) with uncertainties of Ā±0.5 and Ā±0.7 units, respectively. The majority of reporting delays ranged from 9 to 16 s. The largest event, the July 29 2008 M_w5.4 Chino Hills earthquake, triggered a total of 60 CISN stations in epicentral distances of up to 250 km. Magnitude predictions at these stations ranged from M_w4.4 to M_w6.5 with a median of M_w5.6. The closest station would have provided up to 6 s warning at Los Angeles City Hall, located 50 km to the west-northwest of Chino Hills

    Studies in predictor display technique Final report

    Get PDF
    Predictor display technique for manual altitude control, and automatic pitch axis performanc

    Understanding Teacher Leadership in Middle School Mathematics: A Collaborative Research Effort

    Get PDF
    We report ļ¬ndings from a collaborative research effort designed to examine how teachers act as leaders in their schools. We ļ¬nd that teachers educated by the Math in the Middle Institute act as key sources of advice for colleagues within their schools while drawing support from a network consisting of other teachers in the program and university-level advisors. In addition to reporting on our ļ¬ndings, we reļ¬‚ect on our research process, noting some of the practical challenges involved, as well as some of the beneļ¬ts of collaboration

    Improving materials management in electronics manufacturing

    Get PDF
    The aim of this thesis is to determine how in-plant materials management in electronics manufacturing can be improved and to show how a strategy for improvement can be developed for Celestica Limited's Kidsgrove plant. The literature was reviewed to bring out the current issues and topics of interest in materials management. An industrial analysis, through company visits and case studies, was carried out. A number of "best practices" were identified from the literature and the case studies. The "best practices" identified were prioritisation methods, outsourcing of value added services, shop floor control systems, focused stores, tailored logistics, use of computers, trace ability, use of technology or automation, automatic identification, maintaining data integrity, internet-enabled supply-chain, JIT or hybridised JIT-MRP, Kanban, linking and communication of MPS's, application of technology, kitting and recording actual usage of material. [Continues.

    Goal driven theorem proving using conceptual graphs and Peirce logic

    Get PDF
    The thesis describes a rational reconstruction of Sowa's theory of Conceptual Graphs. The reconstruction produces a theory with a firmer logical foundation than was previously the case and which is suitable for computation whilst retaining the expressiveness of the original theory. Also, several areas of incompleteness are addressed. These mainly concern the scope of operations on conceptual graphs of different types but include extensions for logics of higher orders than first order. An important innovation is the placing of negation onto a sound representational basis. A comparison of theorem proving techniques is made from which the principles of theorem proving in Peirce logic are identified. As a result, a set of derived inference rules, suitable for a goal driven approach to theorem proving, is developed from Peirce's beta rules. These derived rules, the first of their kind for Peirce logic and conceptual graphs, allow the development of a novel theorem proving approach which has some similarities to a combined semantic tableau and resolution methodology. With this methodology it is shown that a logically complete yet tractable system is possible. An important result is the identification of domain independent heuristics which follow directly from the methodology. In addition to the theorem prover, an efficient system for the detection of selectional constraint violations is developed. The proof techniques are used to build a working knowledge base system in Prolog which can accept arbitrary statements represented by conceptual graphs and test their semantic and logical consistency against a dynamic knowledge base. The same proof techniques are used to find solutions to arbitrary queries. Since the system is logically complete it can maintain the integrity of its knowledge base and answer queries in a fully automated manner. Thus the system is completely declarative and does not require any programming whatever by a user with the result that all interaction with a user is conversational. Finally, the system is compared with other theorem proving systems which are based upon Conceptual Graphs and conclusions about the effectiveness of the methodology are drawn

    Nivolumab-induced fulminant diabetic ketoacidosis followed by thyroiditis

    Get PDF
    Five days following the 3rd cycle of nivolumab, a monoclonal antibody, which acts as immune checkpoint inhibitor against the programmed cell death protein-1, for metastatic lung adenocarcinoma, a 56-year-old woman presented at the hospital critically ill. On admission, she had severe diabetic ketoacidosis (DKA), as evidenced by venous glucose of 47 mmol/L, blood ketones of 7.5 mmol/L, pH of 6.95 and bicarbonate of 6.6 mmol/L. She has had no personal or family history of diabetes mellitus (DM), while random venous glucose, measured 1 week prior to hospitalisation, was 6.1 mmol/L. On admission, her HbA1c was 8.2% and anti-GAD antibodies were 12 kIU/L (0ā€“5 kU/L), while islet cell antibodies and serum C-peptide were undetectable. Nivolumab was recommenced without the development of other immune-mediated phenomena until 6 months later, when she developed hypothyroidism with TSH 18 U/L and low free T4. She remains insulin dependent and has required levothyroxine replacement, while she has maintained good radiological and clinical response to immunotherapy. This case is notable for the rapidity of onset and profound nature of DKA at presentation, which occurred two months following commencement of immunotherapy. Despite the association of nivolumab with immune-mediated endocrinopathies, only a very small number of patients developing type 1 DM has been reported to date. Patients should be closely monitored for hyperglycaemia and thyroid dysfunction prior to and periodically during immunotherapy

    BLITZEN: A highly integrated massively parallel machine

    Get PDF
    The architecture and VLSI design of a new massively parallel processing array chip are described. The BLITZEN processing element array chip, which contains 1.1 million transistors, serves as the basis for a highly integrated, miniaturized, high-performance, massively parallel machine that is currently under development. Each processing element has 1K bits of static RAM and performs bit-serial processing with functional elements for arithmetic, logic, and shifting

    A V-Diagram for the Design of Integrated Health Management for Unmanned Aerial Systems

    Get PDF
    Designing Integrated Vehicle Health Management (IVHM) for Unmanned Aerial Systems (UAS) is inherently complex. UAS are a system of systems (SoS) and IVHM is a product-service, thus the designer has to take into account many factors, such as: the design of the other systems of the UAS (e.g. engines, structure, communications), the split of functions between elements of the UAS, the intended operation/mission of the UAS, the cost verses benefit of monitoring a system/component/part, different techniques for monitoring the health of the UAS, optimizing the health of the fleet and not just the individual UAS, amongst others. The design of IVHM cannot sit alongside, or after, the design of UAS, but itself be integrated into the overall design to maximize IVHMā€™s potential. Many different methods exist to help design complex products and manage the process. One method used is the V-diagram which is based on three concepts: decomposition & definition; integration & testing; and verification & validation. This paper adapts the V-diagram so that it can be used for designing IVHM for UAS. The adapted v-diagram splits into different tracks for the different system elements of the UAS and responses to health states (decomposition and definition). These tracks are then combined into an overall IVHM provision for the UAS (integration and testing), which can be verified and validated. The stages of the adapted V-diagram can easily be aligned with the stages of the V-diagram being used to design the UAS bringing the design of the IVHM in step with the overall design process. The adapted V-diagram also allows the design IVHM for a UAS to be broken down in to smaller tasks which can be assigned to people/teams with the relevant competencies. The adapted V-diagram could also be used to design IVHM for other SoS and other vehicles or products
    • ā€¦
    corecore