Phenomenography is a well-known empirical research approach that is often used to investigate students' ways of learning programming. Phenomenographic pedagogy is an instructional approach to plan learning and tea...
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ISBN:
(纸本)9781479935932
Phenomenography is a well-known empirical research approach that is often used to investigate students' ways of learning programming. Phenomenographic pedagogy is an instructional approach to plan learning and teaching activities. This theoretical paper gives an overview of prior research in phenomenographic studies of programming and shows how the results from these research studies can be applied to course design. Pedagogic principles grounded in the phenomenographic perspective on teaching and learning are then presented that consider how to tie students' experiences to the course goals (relevance structure) and how to apply variation theory to focus on the desired critical aspects of learning. Building on this, an introductory object-oriented programming course is described as an example of research-based course design. The insights gained from the experience of running the course are shared with the community of computer science educators, as also the benefits and responsibilities for those who wish to adopt the phenomenographic perspective on learning to plan their teaching. The development of an increased awareness of the variation in students' ways of experiencing programming and the need to broaden the context of the programming course are discussed.
This study investigated the difficulties encountered by novice Alice programmers. The researchers conducted one-on-one clinical interviews with 22 10th-grade students at a senior high school in Taipei, Taiwan. The par...
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ISBN:
(纸本)9781450326056
This study investigated the difficulties encountered by novice Alice programmers. The researchers conducted one-on-one clinical interviews with 22 10th-grade students at a senior high school in Taipei, Taiwan. The participants were offered nine Alice programming tasks, each requiring the use of a different set of programming constructs, which included objects, primitive methods, expressions, built-in functions, variables, conditional execution, repetition control, arrays, user-defined methods, and parameter passing. Each participant was observed closely as s/he worked through the given tasks. Whenever an impasse occurred while a student was trying to solve a problem, the observer would intervene by asking a sequence of questions with increasing specificity, ranging from strategic prompts to hints to provides, in order to determine the cause of the impasse. This study summarized the common difficulties for each of the Alice programming constructs used by the participants in the programming tasks, and students' difficulties were categorized into four types: connection, location, usage, and math-and-other difficulties. Students having connection difficulties were unable to apply appropriate programming constructs to implement the actions required; location difficulties indicated students? inability to locating, in the Alice interface, the programming constructs they needed; usage difficulties referred in general to semantic errors in a student's programs; whereas math-and-other difficulties were caused mainly by students' inadequate math knowledge. It is hoped that the findings of this research will help Alice instructors to improve their students' performance by familiarizing themselves with the existence of the identified difficulties, and by addressing the missing conceptions or misconceptions underlying those difficulties.
The object-oriented design used to implement a self-regular formulation of the boundary element method is presented. The self-regular formulation is implemented to four integral equations: the displacement boundary in...
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The object-oriented design used to implement a self-regular formulation of the boundary element method is presented. The self-regular formulation is implemented to four integral equations: the displacement boundary integral equation, and the Somigliana's integral identities for displacement, stress and strain. The boundary-layer effect that arises in the classical BEM on the transition from interior to boundary points is eliminated and thus special integration schemes to treat nearly singular integrals become unnecessary. The self-regular formulations lead to very accurate results. Comparisons of displacements, stress and strain obtained from analytical solutions and the numerical results for bidimensional and tridimensional elastostatics problems are presented, and the self-regular formulation shows strong stability. The implemented code is open-source and is available under the GNU General Public License. (C) 2013 Elsevier Ltd. All rights reserved.
Cloud computing has paved the way for advance of IT-based on demand services. This technology helps decrease capital expenditure and operation costs, solve scalability issue and many more user and provider constraints...
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Cloud computing has paved the way for advance of IT-based on demand services. This technology helps decrease capital expenditure and operation costs, solve scalability issue and many more user and provider constraints. However, development and deployment of distributed applications on cloud environment becomes a more and more complex task. Cloud users must spend a lot of time to prepare, install and configure their applications on clouds. In addition, after development and deployment, the applications almost cannot move from one cloud to another due to the lack of interoperability between them. To address these problems, in this paper we present a novel development and deployment framework for cloud distributed applications/services. Our approach is based on abstraction and object-oriented programming technique, allowing users to easily and rapidly develop and deploy their services into cloud environment. The approach also enables service migration and interoperability among the clouds.
object-oriented languages have recently become common, making register indirect jumps more important than ever. In object-oriented languages, virtual functions are heavily used because they improve programming product...
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object-oriented languages have recently become common, making register indirect jumps more important than ever. In object-oriented languages, virtual functions are heavily used because they improve programming productivity greatly. Virtual function calls usually consist of register indirect jumps, and consequently, programs written in object-oriented languages contain many register indirect jumps. The prediction of the targets of register indirect jumps is more difficult than the prediction of the direction of conditional branches. Many predictors have been proposed for register indirect jumps, but they cannot predict the jump targets with high accuracy or require very complex hardware. We propose a method that resolves jump targets by forwarding execution results. Our proposal dynamically finds the producers of register indirect jumps in virtual function calls. After the execution of the producers, the execution results are forwarded to the processor's front-end. The jump targets can be resolved by the forwarded execution results without requiring prediction. Our proposal improves the performance of programs that include unpredictable register indirect jumps, because it does not rely on prediction but instead uses actual execution results. Our evaluation shows that the IPC improvement using our proposal is as high as 5.4% on average and 9.8% at maximum.
At the conceptual design stage, automobile body is evaluated by simplified frame structure, consisting of thin-walled beams (TWBs). In the automobile practice, design engineers mostly rely on their experience and intu...
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At the conceptual design stage, automobile body is evaluated by simplified frame structure, consisting of thin-walled beams (TWBs). In the automobile practice, design engineers mostly rely on their experience and intuition when making decisions on cross-sectional shape of TWBs. So this paper presents a cross-sectional shape optimization method in order to achieve a high stiffness and lightweight TWB. Firstly, cross-sectional property formulations is summarized and reviewed. Secondly, we build up a shape optimization model to minimize the cross-sectional area and satisfy the stiffness and manufacturing demands. The objective and constraints are nonlinear polynomial functions of the point coordinates defining the cross-sectional shape. Genetic algorithm is introduced to solve this nonlinear optimization problem. Thirdly, object-oriented programming and design patterns are adopted to design and implement the software framework. Lastly, numerical example is used to verify the presented method. This software, "SuperBeam" for short, is released for free and does speed up the conceptual design of automobile body. (C) 2013 Elsevier Ltd. All rights reserved.
The paper presents the application of object-oriented modeling techniques to control software development for complex manufacturing systems, with particular focus on case studies taken from the packaging industry and ...
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The paper presents the application of object-oriented modeling techniques to control software development for complex manufacturing systems, with particular focus on case studies taken from the packaging industry and design patterns that can be abstracted from such case studies. The proposed methodology for control software modeling and implementation is based on a practical approach refined on the basis of on-the-field experience and interactions with control engineers involved in the development projects. The final objective of the paper is to review and analyze patterns for the solution of design and implementation issues that typically arise in the considered application domain. (C) 2012 Elsevier Ltd. All rights reserved.
This contribution presents a methodology to efficiently obtain the numerical and computer solution of dynamic power systems with high penetration of wind turbines. Due to the excessive computational load required to s...
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This contribution presents a methodology to efficiently obtain the numerical and computer solution of dynamic power systems with high penetration of wind turbines. Due to the excessive computational load required to solve the abc models that represent the behavior of the wind turbines, a parallel processing scheme is proposed to enhance the solution of the overall system. Case studies are presented which demonstrate the effectiveness and applications of the proposed methodology. Copyright (C) 2012 John Wiley & Sons, Ltd.
With the arrival of multi-cores for mainstream desktop systems, developers must invest the effort of parallelising their applications in order to benefit from these systems. However, the structure of these interactive...
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With the arrival of multi-cores for mainstream desktop systems, developers must invest the effort of parallelising their applications in order to benefit from these systems. However, the structure of these interactive desktop applications is noticeably different from the traditional batch-like applications of the engineering and scientific fields. We present Parallel Task (short ParaTask), a solution to assist the parallelisation of object-oriented applications, with the unique feature of including support for the parallelisation of graphical user interface applications. In the simple, but common, cases concurrency is introduced with a single keyword. ParaTask sets itself apart from the many existing object-oriented parallelisation approaches by integrating different task types into the same model and its careful adherence to object-oriented principles. Due to the wide variety of parallelisation needs, ParaTask provides intuitive support for dependence handling, non-blocking notification and exception handling in an asynchronous environment as well as supporting a flexible task scheduling runtime (currently work-sharing, work-stealing and a combination of the two are supported). The performance is excellent compared to traditional Java parallelisation approaches, shown using a variety of different workloads.
The program VACTIV - Visual ACTIV - has been developed for an automatic analysis of spectrum-like distributions, in particular gamma-ray spectra or alpha-spectra and is a standard graphical dialog based Windows XX app...
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The program VACTIV - Visual ACTIV - has been developed for an automatic analysis of spectrum-like distributions, in particular gamma-ray spectra or alpha-spectra and is a standard graphical dialog based Windows XX application, driven by a menu, mouse and keyboard. On the one hand, it was a conversion of an existing Fortran program ACTIV [1] to the DELPHI language;on the other hand, it is a transformation of the sequential syntax of Fortran programming to a new object-oriented style, based on the organization of event interactions. New features implemented in the algorithms of both the versions consisted in the following as peak model both an analytical function and a graphical curve could be used;the peak search algorithm was able to recognize not only Gauss peaks but also peaks with an irregular form;both narrow peaks (2-4 channels) and broad ones (50-100 channels);the regularization technique in the fitting guaranteed a stable solution in the most complicated cases of strongly overlapping or weak peaks. The graphical dialog interface of VACTIV is much more convenient than the batch mode of ACTIV. [1] V.B. Zlokazov, Computer Physics Communications, 28 (1982) 27-37. NEW VERSION PROGRAM SUMMARY Program Title: VACTIV Catalogue identifier: ABAC_v2_0 Licensing provisions: no programming language: DELPHI 5-7 Pascal. Computer: IBM PC series. Operating system: Windows XX. RAM: 1 MB Keywords: Nuclear physics, spectrum decomposition, least squares analysis, graphical dialog, object-oriented programming. Classification: 17.6. Catalogue identifier of previous version: ABAC_v1_0 Journal reference of previous version: Comput. Phys. Commun. 28 (1982) 27 Does the new version supersede the previous version?: Yes. Nature of problem: Program VACTIV is intended for precise analysis of arbitrary spectrum-like distributions, e.g. gamma-ray and X-ray spectra and allows the user to carry out the full cycle of automatic processing of such spectra, i.e. calibration, automatic peak search an
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