379 research outputs found

    Re-reading and rehabilitating Basil Bernstein

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    This article constitutes a re-reading of and an attempt to rehabilitate Basil Bernstein, both of which are important in light of the interpretation of Bernstein as a proponent of the verbal deficit view, and the general discrediting of his work on social class differences in the British educational system, as related to what he later called ‘codes’, by scholars like Jensen (Social class and verbal learning, Holt, 1968) and Labov (The logic of non-standard English, Georgetown University Press, 1970), in particular. Exploring whether the international criticism of Bernstein was justified entails both an analysis of articles written by Jensen (Social class and verbal learning, Holt, 1968) and Labov (The logic of non-standard English, Georgetown University Press, 1970) and by Bernstein, notably ‘Language and social class’ and ‘A critique of the concept of compensatory education’, both published in the first volume of Class, codes and control (Bernstein, Class, codes and control, Volume 1. Theoretical studies towards a sociology of language, Schocken Books, 1971). The article argues for the importance of contextualising Bernstein's thoughts on language and society within the socio-political climate framing his scholarship and the development of his ideas as a whole. We show that much of the interpretation of Bernstein is, in fact, a misinterpretation, for which Bernstein was only partly at fault. By rehabilitating some of Bernstein's ideas, it is possible to argue for their relevance today, especially with reference to salient connections between socio-cultural background and performance at school. Furthermore, Labov and Bernstein may not have been so far apart in their thinking as has previously been assumed

    Re-reading and rehabilitating Basil Bernstein

    Get PDF
    This article constitutes a re-reading of and an attempt to rehabilitate Basil Bernstein, both of which are important in light of the interpretation of Bernstein as a proponent of the verbal deficit view, and the general discrediting of his work on social class differences in the British educational system, as related to what he later called ‘codes', by scholars like Jensen (Social class and verbal learning, Holt, 1968) and Labov (The logic of non-standard English, Georgetown University Press, 1970), in particular. Exploring whether the international criticism of Bernstein was justified entails both an analysis of articles written by Jensen (Social class and verbal learning, Holt, 1968) and Labov (The logic of non-standard English, Georgetown University Press, 1970) and by Bernstein, notably ‘Language and social class' and ‘A critique of the concept of compensatory education', both published in the first volume of Class, codes and control (Bernstein, Class, codes and control, Volume 1. Theoretical studies towards a sociology of language, Schocken Books, 1971). The article argues for the importance of contextualising Bernstein's thoughts on language and society within the socio-political climate framing his scholarship and the development of his ideas as a whole. We show that much of the interpretation of Bernstein is, in fact, a misinterpretation, for which Bernstein was only partly at fault. By rehabilitating some of Bernstein's ideas, it is possible to argue for their relevance today, especially with reference to salient connections between socio-cultural background and performance at school. Furthermore, Labov and Bernstein may not have been so far apart in their thinking as has previously been assume

    Investigation of Bearing Fatigue Damage Life Prediction Using Oil Debris Monitoring

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    Research was performed to determine if a diagnostic tool for detecting fatigue damage of helicopter tapered roller bearings can be used to determine remaining useful life (RUL). The taper roller bearings under study were installed on the tail gearbox (TGB) output shaft of UH- 60M helicopters, removed from the helicopters and subsequently installed in a bearing spall propagation test rig. The diagnostic tool was developed and evaluated experimentally by collecting oil debris data during spall progression tests on four bearings. During each test, data from an on-line, in-line, inductance type oil debris sensor was monitored and recorded for the occurrence of pitting damage. Results from the four bearings tested indicate that measuring the debris generated when a bearing outer race begins to spall can be used to indicate bearing damage progression and remaining bearing life

    Attainable Moment Set and Actuation Time of a Bio-Inspired Rotating Empennage

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    Future tactical aircraft will likely demonstrate improvements in efficiency, weight, and control by implementing bio-inspired control systems. This work analyzes a novel control system for a fighter aircraft inspired by the function of – and the degrees of freedom available in – a bird’s tail. The control system is introduced to an existing fighter aircraft design by removing the vertical tail and allowing the horizontal tail surfaces to rotate about the roll axis. Using a low-fidelity aerodynamic model, an analysis on the available controlling moments and actuation speeds of the baseline aircraft is compared to that of the bio-inspired rotating empennage design. The results of this analysis at a takeoff and approach flight condition indicate that the bio-inspired tail design is able to improve upon the baseline in terms of control power available for yaw by up to 170%, while also improving the actuation speed by about 450 milliseconds for moments about the pitch axis. The bio-inspired design is shown to have actuation times that are up to 600 milliseconds slower for generating yawing moments and a reduced roll control contribution from the tail in certain moment combinations. The impacts of these issues on control will need to be determined with analysis at additional flight conditions and a flight dynamics analysis

    A Review of Avian-Inspired Morphing for UAV Flight Control

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    The impressive maneuverability demonstrated by birds has so far eluded comparably sized uncrewed aerial vehicles (UAVs). Modern studies have shown that birds’ ability to change the shape of their wings and tail in flight, known as morphing, allows birds to actively control their longitudinal and lateral flight characteristics. These advances in our understanding of avian flight paired with advances in UAV manufacturing capabilities and applications has, in part, led to a growing field of researchers studying and developing avian-inspired morphing aircraft. Because avian-inspired morphing bridges at least two distinct fields (biology and engineering), it becomes challenging to compare and contrast the current state of knowledge. Here, we have compiled and reviewed the literature on flight control and stability of avian-inspired morphing UAVs and birds to incorporate both an engineering and a biological perspective. We focused our survey on the longitudinal and lateral control provided by wing morphing (sweep, dihedral, twist, and camber) and tail morphing (incidence, spread, and rotation). In this work, we discussed each degree of freedom individually while highlighting some potential implications of coupled morphing designs. Our survey revealed that wing morphing can be used to tailor lift distributions through morphing mechanisms such as sweep, twist, and camber, and produce lateral control through asymmetric morphing mechanisms. Tail morphing contributes to pitching moment generation through tail spread and incidence, with tail rotation allowing for lateral moment control. The coupled effects of wing–tail morphing represent an emerging area of study that shows promise in maximizing the control of its morphing components. By contrasting the existing studies, we identified multiple novel avian flight control methodologies that engineering studies could validate and incorporate to enhance maneuverability. In addition, we discussed specific situations where avian-inspired UAVs can provide new insights to researchers studying bird flight. Collectively, our results serve a dual purpose: to provide testable hypotheses of flight control mechanisms that birds may use in flight as well as to support the design of highly maneuverable and multi-functional UAV designs

    An Assessment of Economic Analysis Methods for Cogeneration Systems

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    Cogeneration feasibility studies were conducted for eleven state agencies of Texas. A net present value (NPV) analysis was used to evaluate candidate cogeneration systems and select the optimum system. CELCAP, an hour-by-hour cogeneration analysis computer program was used to determine the costs used in the NPV analysis. The results of the studies showed that the state could save over $6,000,000 per year in reduced utility bills. Different methods of analyzing the economic performance of a cogeneration system are presented for comparison. Other implications of the study are also discussed

    A Multi-Fidelity Prediction of Aerodynamic and Sonic Boom Characteristics of the JAXA Wing Body

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    This paper presents a detailed comparison between the linear panel solver PANAIR A502 and the in-house Navier–Stokes solver UNS3D for a supersonic low-boom geometry. The high-fidelity flow solver was used to predict both the inviscid and laminar flow about the aircraft geometry. The JAXA wing body was selected as the supersonic low-boom geometry for this study. A comparison of the undertrack near-field pressure signatures showed good agreement between the three levels of model fidelity along the first 0.8L of the signature. Large oscillations in the PANAIR results were observed. The PANAIR discrepancies were traced back to violations of the underlying assumptions within PANAIR: (1) small perturbation velocities and (2) no regions of transonic flow. These violations were due to large changes in surface curvature resulting in a strong expansion wave. While investigating the PANAIR discrepancy, measures of the fundamental assumptions of the Prandtl-Glauert equation used by PANAIR were quantified and used to assess the applicability of PANAIR to a given problem. Further comparison of surface temperatures predicted between the inviscid and laminar solutions was made. It was found that the recovery temperatures predicted by the inviscid solution were 5% less than those predicted by the laminar solution in likely candidate regions for distributed adaptivity. A surface deformation was added to the forward portion of the geometry to asses the viability of a future optimization study in this region. In this study, it was found that the near-field and ground signatures predicted by PANAIR and the UNS3D solutions responded in similar manners to the deformation

    Hormonal control of p53 and chemoprevention

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    Improvements in the detection and treatment of breast cancer have dramatically altered its clinical course and outcome. However, prevention of breast cancer remains an elusive goal. Parity, age of menarche, and age at menopause are major risk factors drawing attention to the important role of the endocrine system in determining the risk of breast cancer, while heritable breast cancer susceptibility syndromes have implicated tumor suppressor genes as important targets. Recent work demonstrating hormonal modulation of the p53 tumor suppressor pathway draws together these established determinants of risk to provide a model of developmental susceptibility to breast cancer. In this model, the mammary epithelium is rendered susceptible due to impaired p53 activity during specific periods of mammary gland development, but specific endocrine stimuli serve to activate p53 function and to mitigate this risk. The results focus attention on p53 as a molecular target for therapies to reduce the risk of breast cancer

    Algorithmic iteration for computational intelligence

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    Machine awareness is a disputed research topic, in some circles considered a crucial step in realising Artificial General Intelligence. Understanding what that is, under which conditions such feature could arise and how it can be controlled is still a matter of speculation. A more concrete object of theoretical analysis is algorithmic iteration for computational intelligence, intended as the theoretical and practical ability of algorithms to design other algorithms for actions aimed at solving well-specified tasks. We know this ability is already shown by current AIs, and understanding its limits is an essential step in qualifying claims about machine awareness and Super-AI. We propose a formal translation of algorithmic iteration in a fragment of modal logic, formulate principles of transparency and faithfulness across human and machine intelligence, and consider the relevance to theoretical research on (Super)-AI as well as the practical import of our results

    Accelerated tibial fracture union in the third trimester of pregnancy: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>We present a case of accelerated tibial fracture union in the third trimester of pregnancy. This is of particular relevance to orthopaedic surgeons, who must be made aware of the potentially accelerated healing response in pregnancy and the requirement for prompt treatment.</p> <p>Case presentation</p> <p>A 40 year old woman at 34 weeks gestational age sustained a displaced fracture of the tibial shaft. This was initially treated conservatively in plaster with view to intra-medullary nailing postpartum. Following an emergency caesarean section, the patient was able to fully weight bear without pain 4 weeks post injury, indicating clinical union. Radiographs demonstrated radiological union with good alignment and abundant callus formation. Fracture union occurred within 4 weeks, less than half the time expected for a conservatively treated tibial shaft fracture.</p> <p>Conclusion</p> <p>Long bone fractures in pregnancy require clear and precise management plans as fracture healing is potentially accelerated. Non-operative treatment is advisable provided satisfactory alignment of the fracture is achieved.</p
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