Abductive science inquiry using mobile devices in the classroom

Recent advancements in digital technology have attracted the interest of educators and researchers to develop technology-assisted inquiry-based learning environments in the domain of school science education. Traditionally, school science education has followed deductive and inductive forms of inquiry investigation, while the abductive form of inquiry has previously been sparsely explored in the literature related to computers and education. We have therefore designed a mobile learning application ‘ThinknLearn’, which assists high school students in generating hypotheses during abductive inquiry investigations. The M3 evaluation framework was used to investigate the effectiveness of using ‘ThinknLearn’ to facilitate student learning. The results indicated in this paper showed improvements in the experimental group's learning performance as compared to a control group in pre-post tests. In addition, the experimental group also maintained this advantage during retention tests as well as developing positive attitudes toward mobile learning.     

Promoting argument in the science classroom: A rhetorical perspective

Abstract:

This paper draws on contemporary scholarship in the field of rhetoric and on recent research in science education conducted from a rhetorical perspective. Beginning with a brief sketch of the principal ideas used in the study of rhetoric, it argues that such a perspective provides a useful insight into the aims and purposes of the science teacher, arguing that science teachers are, in essence, engaged in a process of rhetorical argument. Likewise, a rhetorical characterization of the practice of science itself shows that argument is one of its central features. Therefore, if developing epistemic goals and an understanding about science within science education is important, the consideration of argument and reasoning should be a core feature of the practice of science education. A number of problems are identified with such change, including a shortage of suitable pedagogic materials and the lack of experience of science teachers in the use of deliberative discussion. More fundamentally, it is suggested that there is an inherent contradiction between the ‘rhetoric of conclusions’ practised by science teachers and the ‘rhetoric of dialogical argument’ practised by scientists. The resolution of this contradiction can be achieved only by a radical disjuncture in the nature and form of contemporary science education.     

Casting shadows with approximated object space accuracy by means of a modified Z-buffer

Shadows are important in enhancing both the realism and the intelligibility of synthetic 2D images of 3D scenes. In order to determine which part of a scene is in shadow, numerous algorithms have been developed. The Z-buffer shadow algorithm and its descendants have proved to be both efficient and easy to implement. However, in casting shadows, the aliasing introduced by the Z-buffer point sampling is notorious. Therefore a new method that is based on a modification of the Z-buffer has been developed. This method deals with the aliasing problem but preserves the strengths of the Z-buffer algorithm. Moreover, as a side effect, the information stored in the modified Z-buffer allows accurate antialiasing of the resulting image.     

Pick emerges from the shadows

While battle rages in the 16 bit micro market over the rival merits of CP/M-86, MS/DOS, MP/M-86 and Unix, another strong contendor may beat them all to become the standard for business use. Pick is emerging from its years of seclusion as an operating system well-suited to end users; a fact reflected by the 20,000-strong, and growing, user base and the number of recent micro implementations.     

Using the interactive whiteboard to resource continuity and support multimodal teaching in a primary science classroom

Abstract   All communication is inherently multimodal, and understandings of science need to be multidimensional. The interactive whiteboard offers a range of potential benefits to the primary science classroom in terms of relative ease of integration of a number of presentational and ICT functions, which, taken together, offers new opportunities for fostering multifaceted pedagogic strategies. In this case study, we examine in detail how a teacher pursues two themes across four science lessons. We examine how the teacher creates continuity in her students' learning experiences through taking up some of the affordances of the IWB in order to represent scientific phenomena and engage children in activities to consolidate their understandings. Support is offered for the notion that while pedagogic goals and strategies must determine the selection of tools, rather than the 'tail wagging the dog' as in technology-focussed hyperbole, planned use of the interactive whiteboard, conceptualized as a 'heterogeneous mediational tool kit' ( Wertsch 1991 ), can be effectively integrated into teaching practice.     

Developing a NFC-equipped smart classroom: Effects on attitudes toward computer science

This study describes a smart classroom system that integrates near field communication (NFC) technology to automate attendance management, locate students, and provide real-time student feedback. The proposed system’s attendance management feature can conserve time and reduce paper-work because students use their NFC-enabled smartphones or NFC smart cards to register their attendance automatically. Also, the system’s student-positioning feature is particularly useful for teaching large classes because teachers typically experience difficulties in both recognizing students and familiarizing themselves with their students’ learning progress. In addition, the real-time feedback function could be beneficial especially for Asian students because they are usually reluctant to express their opinions during class. This study also evaluates the proposed system’s effect on students’ attitude toward science education by applying relevant theories. Our case study of a computer science course shows that the attitudes of students toward computer science generally improved following the implementation of the proposed system. Because more than half of the measures from the aspects of learning computer science at school and importance of computer science are positive and significant, this indicates that students find computer science more interesting, expecting, exciting, beneficial, helpful, and appealing after the using the proposed system.     

Robotics in the classroom

This article presents an integrated approach for incorporating robotics into secondary education with the objective of further engaging students through an exciting application of math, computers, and science. One of the principal objectives of this university-based outreach effort is to promote the creation of independent programs at the secondary-school level in New Mexico by providing a structured set of resources from which the schools may begin. These resources include an adaptable mobile robot kit with detailed do-it-your-self online instructions, various Web-based course offerings with material directed to both secondary students and teachers, and a personnel support structure, including college engineering faculty, secondary teachers, practicing engineers, undergraduate engineering students, and junior-high and high-school students. An outreach program to integrate robotics into secondary education.     

On the removal of shadows from images

This paper is concerned with the derivation of a progression of shadow-free image representations. First, we show that adopting certain assumptions about lights and cameras leads to a 1D, gray-scale image representation which is illuminant invariant at each image pixel. We show that as a consequence, images represented in this form are shadow-free. We then extend this 1D representation to an equivalent 2D, chromaticity representation. We show that in this 2D representation, it is possible to relight all the image pixels in the same way, effectively deriving a 2D image representation which is additionally shadow-free. Finally, we show how to recover a 3D, full color shadow-free image representation by first (with the help of the 2D representation) identifying shadow edges. We then remove shadow edges from the edge-map of the original image by edge in-painting and we propose a method to reintegrate this thresholded edge map, thus deriving the sought-after 3D shadow-free image.     

对阴影说不

如果你留意，就会发现每一本介绍摄影基本技巧的书籍都会或多或少地涉及到闪光补光的内容。许多白天拍摄的照片一般都会因为严重逆光而出现部分曝光不足的画面，这种情况一般发生在海滩或是其它日光充裕的地方，     

Overcoming shadows in 3-source photometric stereo

Light occlusions are one of the most significant difficulties of photometric stereo methods. When three or more images are available without occlusion, the local surface orientation is overdetermined so that shape can be computed and the shadowed pixels can be discarded. In this paper, we look at the challenging case when only two images are available without occlusion, leading to a one degree of freedom ambiguity per pixel in the local orientation. We show that, in the presence of noise, integrability alone cannot resolve this ambiguity and reconstruct the geometry in the shadowed regions. As the problem is ill-posed in the presence of noise, we describe two regularization schemes that improve the numerical performance of the algorithm while preserving the data. Finally, the paper describes how this theory applies in the framework of color photometric stereo where one is restricted to only three images and light occlusions are common. Experiments on synthetic and real image sequences are presented.     

Algorithms for antialiased cast shadows

The ability to render the shadows cast by objects in a scene is of prime importance in augmenting the realism of sequences produced by image synthesis algorithms. From a theoretical standpoint, the problem does not present a great number of difficulties: It requires an integration in the process, of the viewpoint from the light source and the utilization of this information when calculating the lighting of the pixels. The purpose of this study is not to present a radically new approach, but to explore in depth the most common problem present in these images, the aliasing, or more generally speaking, the sampling problem. This work has implied a specific approach in the hidden surface determination, the introduction of a variation of the already used A-buffers or Z-buffers, as well as an extensive study of the filtering problem.     

Single view compositing with shadows

In this paper, we describe how geometrically correct and visually realistic shadows may be computed for objects composited into a single view of a target scene. Compared to traditional single view compositing methods, which either do not deal with the shadow effects or manually create the shadows for the composited objects, our approach efficiently utilizes the geometric and photometric constraints extracted from a single target image to synthesize the shadows consistent with the overall target scene for the inserted objects. In particular, we explore (i) the constraints provided by imaged scene structure, e.g. vanishing points of orthogonal directions, for camera calibration and thus explicit determination of the locations of the camera and the light source; (ii) the relatively weaker geometric constraint, the planar homology, that models the imaged shadow relations when explicit camera calibration is not possible; and (iii) the photometric constraints that are required to match the color characteristics of the synthesized shadows with those of the original scene. For each constraint, we demonstrate the working examples followed by our observations. To show the accuracy and the applications of the proposed method, we present the results for a variety of target scenes, including footage from commercial Hollywood movies and 3D video games.     

Databases in the classroom*

Handling information on a variety of media from difference sources has always been an integral part of learning. Children now have the opportunity to use information-handling programs on microcomputers that support the existing curriculum and open up new possibilities for self-directed enquiry learning. This paper summarizes the background to the development of the QUEST ‘family’ of programs and demonstrates the way they are used in History and Geography. Comparisons are also made with other database programs.     

Reasoning about shadows in a mobile robot environment

This paper describes a logic-based formalism for qualitative spatial reasoning with cast shadows (Perceptual Qualitative Relations on Shadows, or PQRS) and presents results of a mobile robot qualitative self-localisation experiment using this formalism. Shadow detection was accomplished by mapping the images from the robot’s monocular colour camera into a HSV colour space and then thresholding on the V dimension. We present results of self-localisation using two methods for obtaining the threshold automatically: in one method the images are segmented according to their grey-scale histograms, in the other, the threshold is set according to a prediction about the robot’s location, based upon a qualitative spatial reasoning theory about shadows. This theory-driven threshold search and the qualitative self-localisation procedure are the main contributions of the present research. To the best of our knowledge this is the first work that uses qualitative spatial representations both to perform robot self-localisation and to calibrate a robot’s interpretation of its perceptual input.     

A fourier theory for cast shadows

Cast shadows can be significant in many computer vision applications, such as lighting-insensitive recognition and surface reconstruction. Nevertheless, most algorithms neglect them, primarily because they involve nonlocal interactions in nonconvex regions, making formal analysis difficult. However, many real instances map closely to canonical configurations like a wall, a V-groove type structure, or a pitted surface. In particular, we experiment with 3D textures like moss, gravel, and a kitchen sponge, whose surfaces include canonical configurations like V-grooves. This paper takes a first step toward a formal analysis of cast shadows, showing theoretically that many configurations can be mathematically analyzed using convolutions and Fourier basis functions. Our analysis exposes the mathematical convolution structure of cast shadows and shows strong connections to recent signal-processing frameworks for reflection and illumination.     

Shadow geometry maps for alias-free shadows

Shadow maps sample scene visibility in the light source space and offer an efficient solution to generate hard shadows.However,they suffer from aliasing artifacts because of discretization errors,inadequate resolution and projection distortion.In this paper,we propose the shadow geometry map method,where a shadow depth map is augmented by storing geometry information about scenes.This leads to a new shadowrendering algorithm that combines a supersampling filter,a geometry-aware reconstruction kernel and an irregular sampling filter.Our method produces high quality alias-free and subpixel supersampling shadow rendering and retains the simplicity and the efficiency of shadow maps.We show that the algorithm pipeline is efficiently parallelized using current programmable graphics hardware and that our method is capable of generating high quality hard shadows.