6,906 research outputs found
Using performance assessment in secondary school mathematics: an empirical study in a Singapore classroom
No full textThis article reports an exploratory study on using performance assessment in mathematics instruction in a high-performing secondary school in Singapore. An intact mathematics class participated in the study, and received chapter-based performance tasks as intervention during regular mathematics lessons for about one and a half school years. The performance tasks used included authentic and/or open-ended tasks. The students’ academic achievements and attitudes in mathematics were compared with a comparison class that did not receive the intervention. Both quantitative and qualitative data were collected, mainly through questionnaire surveys, performance task tests, conventional school exams, and interviews with students and teachers. The results suggest that the students receiving the intervention performed significantly better than their counterparts in solving conventional exam problems, and in general they also showed more positive changes in attitudes towards mathematics and mathematics learning. The students from the experimental class also expressed positive views about the benefits of using performance tasks in promoting their ability in higher order thinking, though no statistically significant difference was detected between the two classes of students in solving unconventional tasks before and after intervention. Overall, the results appear to support teachers’ using contextualised problems in real life situations and open-ended investigations in students’ learning of mathematic
Richardson, Barbauld, and the construction of an early modern fan club
No full textMPhilMuch has been written about the life and long works of the eighteenth century epistolary novelist, Samuel Richardson, but the prospect of his position as the first celebrity novelist – responsible for courting his own fame as well as initiating his own fan club – has largely been ignored. The body of manuscripts housed at the National Art Library in the Victoria and Albert Museum in London provides the modern scholar with evidence of the skeletal beginnings of an early fan club. This thesis aims to show how these manuscripts were turned into a saleable commodity by the publisher and entrepreneur Richard Phillips, while under the guiding hand of another, slightly later, literary celebrity, Anna Laetitia Barbauld. In order to restore Richardson’s reputation amongst a new nineteenth century audience, Barbauld was required to construct her own idea of him as an eighteenth century celebrity author, and in doing so the insecurities of a self-professed, apparently diffident man, are revealed. Barbauld’s capacious, but heavily edited selection of letters is analyzed in this thesis, providing ample evidence that Richardson’s correspondents were more than just eager letter writers. By using Barbauld’s biography of Richardson this thesis aims to show how she manipulates the genre of life writing in her construction of him.
This thesis offers an alternative reading of how the Richardson manuscripts are viewed, redefining them as not simply a collection of letters, but as a collective entity, deliberately selected and archived as evidence of an early modern fan club, and its celebrity managing director
Extending theories of the constitution of organization
No full textThis paper seeks to extend current theories of the constitution of organizations, specifically those related to communication, secrecy, and gossip as a form of communication. It is suggested that at the intersection of these three is secret or confidential gossip, which has a powerful, albeit hidden, capacity to construct organizational relationships, including group formation and organizational socialization
Potential biomarkers for immunotherapy in non-small-cell lung cancer
No full textFor individuals with advanced or metastatic non-small cell lung cancer (NSCLC), the primary treatment is platinum-based doublet chemotherapy. Immune checkpoint inhibitors (ICIs), primarily PD-1/PD-L1 and CTLA-4, have been found to be effective in patients with NSCLC who have no EGFR/ALK mutations. Furthermore, ICIs are considered a standard therapy. The quantity of fresh immunogenic antigens discovered by cytotoxic T cells was measured by PD-L1 expression and tumor mutational burden (TMB), which were the first biomarkers assessed in clinical trials. However, immunotherapy did not have response efficacy markers similar to targeted therapy, highlighting the significance of newly developed biomarkers. This investigation aims to review the research on immunotherapy for NSCLC, focusing primarily on the impact of biomarkers on efficacy prediction to determine whether biomarkers may be utilized to evaluate the effectiveness of immunotherapy
Charge trapping characterisation and electrical performance of thermally aged polymeric cable insulation
No full textWith the growing interest in high voltage direct current (HVDC) transmission systems, the impact of space charge on insulation has attracted more attention recently and the traps in the materials are considered to be one of the dominant factors that affects the electrical performance of the insulation. Meanwhile, in past decades, significant effort has been made to establish the relationship between ageing and the lifetime of electrical insulating materials so that the degree of ageing of insulation can be used to predict its lifetime. Generally, the chemical structure of dielectrics could be affected by ageing, and further electrical performance such as breakdown strength, dielectric loss, and conductivity will change. However, we still cannot use a simple and clear model with few characteristics to connect ageing with chemical and electrical changes to predict insulation lifetime. So, in my research, space charge behaviour is used to explain the ageing process in a HVDC system and the trapping parameters are the key to linking ageing with other electrical properties. In this case, how to use space charge dynamics to estimate the trap parameters, the impact of ageing on trapping, and the relation between trapping and electrical performance are tough problems. The relationship between ageing and trapping parameters will be explored. Hence, the initial trapping parameters and breakdown strength could be used to infer breakdown behaviour after ageing, which means trapping parameters can be used to assess the degree of ageing of the insulation in a HVDC system and predict dielectrics lifetime. In this thesis, the structure, morphology, and impact on the properties of polyethylene (PE) will be introduced and the thermal ageing mechanisms will be explored. In order to study the innate character of space charge, the mechanism of charge injection and transport in dielectric materials will be presented. Moreover, previous research on space charge behaviours in polymeric materials is reviewed for clear research direction. The relative space charge and trapping parameters model will also be introduced. The experimental work focuses on the low‐density PE (LDPE) films with different degrees of thermal ageing, its impact on charge trap density, and changes in electrical breakdown strength. The samples were aged in two environments, nitrogen and air, at various temperatures over different lengths of time. The degree of ageing of the samples was characterised using Fourier‐transform infrared (FTIR), and differential scanning calorimetry (DSC) was used to investigate the impact of thermal ageing on the internal structure and morphology of PE. Meanwhile, the Raman technique was used to detect the degree of thermal ageing in different layers inside of the films. Space charge dynamics for ageing LDPE were measured using the pulsed electroacoustic (PEA) technique. In addition, the electrical breakdown strength of the aged samples was measured, and breakdown data was processed using the Weibull distribution. DC electrical conductivity was measured to verify the hypothesis about the substantial growth of conductivity in seriously aged LDPE and is the reason a rapid charge decay rate was observed in these samples. The results of a chemical analysis show that thermal ageing in the air leads to a gradual increase in the thermo‐oxidative‐degree of LDPE. However, the crystallinity of aged films cannot be impacted by the degree of oxidation but the ageing temperature. Nitrogen‐aged LDPE, with a notably lower carbonyl index, shows similar trends in DSC tests with air‐aged specimens. As for space charge dynamics, traps are introduced into the samples during thermal ageing in the fan oven and deep traps dominate the process. At the early stage of the ageing process, a small number of deep traps in the vicinity of the electrodes can suppress further charge injection, which results in the increase in breakdown strength and the reduction of DC conductivity. During the sustained rise of the degree of ageing, more deep and shallow traps are introduced into the sample, thus higher DC conductivity and lower breakdown strength are detected due to the large amount of charge injection. The space charge behaviours of nitrogen‐aged LDPE suggest that deep traps are mainly introduced by oxidation and shallow traps are generated by the thermal effect. Trapping parameters (injection barrier, trap density, and trap energy level) are evaluated using an improved model. The injection barrier is enhanced by thermal ageing due to surface oxidation. Thermal ageing can introduce traps into LDPE, but the test method for deep ageing samples needs to be modified. The traps introduced by thermal ageing have a higher trap energy leve
Development of a rotor model for the numerical simulation of helicopter exterior flow-fields
No full textIncludes bibliographical references (leaves 84-85).A numerical methodology is developed to model the effect of a rotor on the surrounding flow-field. The model calculates the time-averaged aerodynamic forces exerted on the air by the fan blades within the blade-swept region, and permits the user to specify blade properties such as cross-sectional profile and orientation at a particular radial and azimuthal location. The calculated forces are included as source terms within the Reynolds-averaged Navier-Stokes equations for an incompressible fluid, which are solved by the commercial CFD solver, FLUENT. The effects of turbulence are incorporated through the use of Launder and Spalding's k-g turbulence model. This method is selected as being the most efficient use of the resources available, giving the economic advantages of a steady simulation, while allowing radial and azimuthal variations of rotor characteristics. In order to validate the accuracy of the numerical model for both aligned and non-aligned inflow conditions, results are compared with experimental data reported for an axial flow fan. Agreement between experimental and numerical results is excellent to good. Fan static pressure rise is closely predicted by the numerical solution, while fan power consumption and fan static efficiency are under and over-predicted respectively. This error may be attributed to frictional losses not accounted for in the numerical model. These include physical rotational instabilities, leading to increased mechanical losses, and tip effects due to the clearance between the fan blade tips and the fan casing. Trends are nevertheless consistently predicted by the numerical model for inflow angles up to 45°, and for the range of blade pitch settings used. The adverse effect of off-axis inflow on the fan static pressure rise is numerically predicted, while fan power consumption is found to remain independent of inflow angle, as had been experimentally observed. The rotor model is finally integrated with the fuselage of the CIRSTEL (Combined Infra-Red Suppression and Tail rotor Elimination) prototype in an analysis of the helicopter exterior flow-field. No experimental data for this configuration was available for validation purposes. However, the model is used in the simulation of several common helicopter flight conditions. Results are presented graphically, and generally indicate good agreement with physically observed phenomena
Thermal ageing and its impact on charge trapping parameters in LDPE
No full textWith the riding use of HVDC transmission systems, the impact of space charge on insulation has attracted attention for several decades and the traps in the dielectrics are considered as the dominated factor of ageing. In our research, we aim to establish a model to connect ageing and lifetime for the insulation materials in HVDC systems, and the space charge characteristics are used to extract parameters associated with traps. In this paper, the trapping parameters of ageing samples estimated by an improved model will be described, and a comparative analysis based on experiments data and simulation results will be made. Commercially available additive-free LDPE films were thermally aged in fan oven with different ageing degrees. Space charge dynamics were measured using the pulsed electroacoustic (PEA) technique and further trapping parameters including injection barrier, the depth of deep and shallow traps and trap density were estimated. Both polarization and depolarization stages and the neutralization process were taken into considered in this model. It has been found that at the early stage of thermal ageing in the air, a small number of deep traps was introduced near the surface of LDPE films, which can hinder further charge injected. Further ageing will generate more shallow and deep traps, and deep traps dominate the impact on electrical properties.</p
Fan Fiction and Copyright: Outsider Works and Intellectual Property Protection
No full textAs long as there have been fans, there has been fan fiction. There seems to be a fundamental human need to tell additional stories about the characters after the book, series, play or movie is over. But developments in information technology and copyright law have put these fan stories at risk of collision with the content owners’ intellectual property rights. Fan fiction has long been a nearly invisible form of outsider art, but over the past decade it has grown exponentially in volume and in legal importance. Because of its nature, authorship, and underground status, fan fiction stands at an intersection of key issues regarding property, sexuality, and gender. In Fan Fiction and Copyright, author Aaron Schwabach examines various types of fan-created content and asks whether and to what extent they are protected from liability for copyright infringement. Professor Schwabach discusses examples of original and fan works from a wide range of media, genres, and cultures. From Sherlock Holmes to Harry Potter, fictional characters, their authors, and their fans are sympathetically yet realistically assessed. Fan Fiction and Copyright looks closely at examples of three categories of disputes between authors and their fans: Disputes over the fans’ use of copyrighted characters, disputes over online publication of fiction resembling copyright work, and in the case of J.K. Rowling and a fansite webmaster, a dispute over the compiling of a reference work detailing an author's fictional universe. Offering more thorough coverage of many such controversies than has ever been available elsewhere, and discussing fan works from the United States, Brazil, China, India, Russia, and elsewhere, Fan Fiction and Copyright advances the understanding of fan fiction as transformative use and points the way toward a safe harbor\u9d for fan fiction
Learning of algorithms: a theoretical model with focus on cognitive development
No full textTaking a broad perspective on algorithm in mathematics, the author presents a theoretical model about the learning and teaching of algorithm with focus on students’ cognitive development. The model consists of three cognitive levels: 1. Knowledge and Skills, 2. Understanding and Comprehension, and 3. Evaluation and Construction. The model suggests that teaching and learning of algorithm does not simply mean routine learning, memorization, or lead to a low level of cognition. The paper also discusses different teaching strategies and activities that can be used to support students’ cognitive development at different cognitive levels
The author in the postinternet age: Fan works, authorial function, and the archive
No full textFifty years since Roland Barthes proclaimed the death of the author, there still exists difficulty in framing the nature of interaction between commercial (professional) creators and fan (transformative) authors. In the postinternet age, the visibility of unsanctioned (or tacitly sanctioned) derivative fictional works has only increased, as have the number of commercial creators with experience in creating derivative works for a fan audience. It has therefore become necessary to interrogate whether the author has truly died in the Barthian sense, and if not, what role the construct of the author plays in today's popular mediascape. In an analysis of the Foucauldian author function (that is, the role discursively constructed authors play relative to their work) assessing both Euro-American and Japanese histories of fan practice, a move to a more open-source style of fan practice is evident. The author in an open-source fandom functions as a heuristic device through which fans may access and search the database, as well as a means of decentralizing commercial authority over media content
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