5,192 research outputs found

    L2 の授業において言語学習者の集中力を高める取り組み

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    本稿では、筆者が授業プランを作成するときに活用している4 つの言語教授方法について論じる。それらの教授方法とは、学習者に自信を持たせること、協同学習法の採用、正確さよりも流暢さを優先すること、そして教室におけるテクノロジーの活用である。それぞれについて、L2 の授業において学習者の学習意欲と集中力を高めるという視点から議論する。また、それぞれの教授方法の定義や、それらを採用した理由を述べるにあたっては、その都度、適切なSLA の文献について言及する。読者が自身の授業で実践するにあたって役立つものとなるよう、徹底的な検証を試みる。さらに、筆者がここで議論する教授方法は、全ての言語学習者を対象としたものではなく、主に第2 言語の習得に消極的な学習者を対象としたものであることを強調したい。本稿は、筆者を含む言語教員が、その教授法を導いている理論的な根拠に注意を払い続けることを促すという意味において、有益なものである。This paper discusses four language teaching practices upon which the writer relies when designing lesson plans: building student confidence, employment of collaborative learning education, prioritizing fluency over accuracy, and utilizing technology in the classroom. Each of these items is presented with an eye toward enhancing student motivation and encouraging student engagement in the L2 classroom. The writer calls on relevant SLA literature to define each of the four teaching practices upon which the paper is focused, as well as to discuss his reasons for employing each method. Effort is made to provide a thorough review of each teaching practice in order to provide readers with a blueprint for utilizing them in their own classrooms. Throughout, the author is careful to stress that the methods he discusses herein are not intended to address the needs of all language learners, but primarily those who possess less resolve for second language study. This article is productive in that it encourages language teachers, the author included, to remain mindful of the rationale guiding their approach to teaching

    Adaptable processes

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    We propose the concept of adaptable processes as a way of overcoming the limitations that process calculi have for describing patterns of dynamic process evolution. Such patterns rely on direct ways of controlling the behavior and location of running processes, and so they are at the heart of the adaptation capabilities present in many modern concurrent systems. Adaptable processes have a location and are sensible to actions of dynamic update at runtime; this allows to express a wide range of evolvability patterns for concurrent processes. We introduce a core calculus of adaptable processes and propose two verification problems for them: bounded and eventual adaptation. While the former ensures that the number of consecutive erroneous states that can be traversed during a computation is bound by some given number k, the latter ensures that if the system enters into a state with errors then a state without errors will be eventually reached. We study the (un)decidability of these two problems in several variants of the calculus, which result from considering dynamic and static topologies of adaptable processes as well as different evolvability patterns. Rather than a specification language, our calculus intends to be a basis for investigating the fundamental properties of evolvable processes and for developing richer languages with evolvability capabilities

    A New Approach to Coding in Content Based MANETs

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    In content-based mobile ad hoc networks (CB-MANETs), random linear network coding (NC) can be used to reliably disseminate large files under intermittent connectivity. Conventional NC involves random unrestricted coding at intermediate nodes. This however is vulnerable to pollution attacks. To avoid attacks, a brute force approach is to restrict the mixing at the source. However, source restricted NC generally reduces the robustness of the code in the face of errors, losses and mobility induced intermittence. CB-MANETs introduce a new option. Caching is common in CB MANETs and a fully reassembled cached file can be viewed as a new source. Thus, NC packets can be mixed at all sources (including the originator and the intermediate caches) yet still providing protection from pollution. The hypothesis we wish to test in this paper is whether in CB-MANETs with sufficient caches of a file, the performance (in terms of robustness) of the restricted coding equals that of unrestricted coding. In this paper, we examine and compare unrestricted coding to full cache coding, source only coding, and no coding. As expected, we find that full cache coding remains competitive with unrestricted coding while maintaining full protection against pollution attacks

    Dynamic analysis of runout correction in milling

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    Tool runout and its effects is an important area of research within modelling, simulation, and control of milling forces. Tool runout causes tool cutting edges to experience uneven forces during milling. This fact also affects tool life and deteriorates workpiece surface quality. In this article a procedure, in order to diminish the effects of tool runout, is presented. The procedure is based on chip thickness modification by means of the fast correction of the tool feed rate. Dynamic feed rate modification is provided by superposing our own design of a fast feed system driven by a piezoelectric actuator to the conventional feed drive of the CNC machine tool. Previously, a model of the dynamic behaviour of the system was developed to analyze the influence of fast feed rate modification on cutting forces. The model incorporates the piezoelectric actuator response as well as the structural dynamics of the tool and the designed Fast Feed Drive System (FFDS). Simulated and experimental results presented in this paper show the effectiveness and benefits of this new tool runout correction procedure

    Scientific Objectives for UV/Visible Astrophysics Investigations: A Summary of Responses by the Community (2012)

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    Following several recommendations presented by the Astrophysics Decadal Survey 2010 centered around the need to define "a future ultraviolet-optical space capability," on 2012 May 25, NASA issued a Request for Information (RFI) seeking persuasive ultraviolet (UV) and visible wavelength astrophysics science investigations. The goal was to develop a cohesive and compelling set of science objectives that motivate and support the development of the next generation of ultraviolet/visible space astrophysics missions. Responses were due on 10 August 2012 when 34 submissions were received addressing a number of potential science drivers. A UV/visible Mission RFI Workshop was held on 2012 September 20 where each of these submissions was summarized and discussed in the context of each other. We present a scientific analysis of these submissions and presentations and the pursuant measurement capability needs, which could influence ultraviolet/visible technology development plans for the rest of this decade. We also describe the process and requirements leading to the inception of this community RFI, subsequent workshop and the expected evolution of these ideas and concepts for the remainder of this decade.Comment: 22 pages, 1 figure, 3 table

    A new mechanism for generating broadband pulsar-like polarization

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    Observational data imply the presence of superluminal electric currents in pulsar magnetospheres. Such sources are not inconsistent with special relativity; they have already been created in the laboratory. Here we describe the distinctive features of the radiation beam that is generated by a rotating superluminal source and show that (i) it consists of subbeams that are narrower the farther the observer is from the source: subbeams whose intensities decay as 1/R instead of 1/R^2 with distance (R), (ii) the fields of its subbeams are characterized by three concurrent polarization modes: two modes that are 'orthogonal' and a third mode whose position angle swings across the subbeam bridging those of the other two, (iii) its overall beam consists of an incoherent superposition of such coherent subbeams and has an intensity profile that reflects the azimuthal distribution of the contributing part of the source (the part of the source that approaches the observer with the speed of light and zero acceleration), (iv) its spectrum (the superluminal counterpart of synchrotron spectrum) is broader than that of any other known emission and entails oscillations whose spacings and amplitudes respectively increase and decrease algebraically with increasing frequency, and (v) the degree of its mean polarization and the fraction of its linear polarization both increase with frequency beyond the frequency for which the observer falls within the Fresnel zone. We also compare these features with those of the radiation received from the Crab pulsar.Comment: 8 pages, 8 figure

    Flood lamination strategy based on a three-flood-diversion-area system management

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    The flood lamination has for principal objective to maintain a downstream flow at a fixed lamination level. For this goal, it is necessary to proceed to the dimensioning of the river system capacity and to make sure of its management by taking into account socio-economic and environmental constraints. The use of flood diversion areas on a river has for main interest to protect inhabited downstream areas. In this paper, a flood lamination strategy aiming at deforming the wave of flood at the entrance of the zone to be protected is presented. A transportation network modeling and a flow optimization method are proposed. The flow optimization method, is based on the modeling of a Min-Cost-Max-flow problem with a linear programming formulation. The optimization algorithm used in this method is the interior-point algorithm which allows a relaxation of the solution of the problem and avoids some non feasibility cases due to the use of constraints based on real data. For a forecast horizon corresponding to the flood episode, the management method of the flood volumes is evaluated on a 2D simulator of a river equipped with a three-flood-diversion- area system. Performances show the effectiveness of the method and its ability to manage flood lamination with efficient water storage
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