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1.
Students’ judgments about “what counts” as mathematics in and out of school have important consequences for problem solving and transfer, yet our understanding of the source and nature of these judgments remains incomplete. Thirty-five sixth grade students participated in a study focused on what activities students judge as mathematical, and how they make their judgments. Students completed a photo sorting activity; took, viewed, and captioned their own photos of mathematics; viewed and commented on classmates’ photos; and participated in a small group discussion. Across multiple sources of data, findings showed that students attended to two major features of photos and activities when making judgments: surface cues present in the photos, such as numbers and money, and the possibility for mathematical action. Some students looked for the possibility of mathematics, while others asked if mathematics was necessary. Students also gave higher ratings to activities with which they had personal experience. The article concludes with possible implications for practice. 相似文献
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Gladys Sterenberg 《Journal of Mathematics Teacher Education》2008,11(2):89-105
Research suggests that understanding new images of mathematics is very challenging and can contribute to teacher resistance.
An explicit exploration of personal views of mathematics may be necessary for pedagogical change. One possible way for exploring
these images is through mathematical metaphors. As metaphors focus on similarities, they can be used to express already-held
perceptions about the nature of mathematics. In addition to providing a way of talking about current views of mathematics,
the analogous dimensions of metaphors can prompt new ways of thinking about these images. In this article, I consider the
use of metaphors as a strategy for explicating elementary teachers’ views of mathematics. I claim that the investigation of
metaphors of mathematics helped create a shared communicative space and enhanced the quality of the discussion with the teachers.
In particular, our exploration of the metaphor mathematics is a language encouraged a consideration of the humanistic dimensions of mathematics and contributed to a varied re-imaging of mathematics. 相似文献
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Karthigeyan Subramaniam Pamela Esprívalo Harrell David Wojnowski 《Research in Science & Technological Education》2013,31(1):66-89
Background and purpose : This study details the use of a conceptual framework to analyze prospective teachers’ images of scientists to reveal their context-specific conceptions of scientists. The conceptual framework consists of context-specific conceptions related to positive, stereotypical and negative images of scientists as detailed in the literature on the images, role and work of scientists. Sample, design and method : One hundred and ninety-six drawings of scientists, generated by prospective teachers, were analyzed using the Draw-A-Scientist-Test Checklist (DAST-C), a binary linear regression and the conceptual framework. Results : The results of the binary linear regression analysis revealed a statistically significant difference for two DAST-C elements: ethnicity differences with regard to drawing a scientist who was Caucasian and gender differences for indications of danger. Analysis using the conceptual framework helped to categorize the same drawings into positive, stereotypical, negative and composite images of a scientist. Conclusions : The conceptual framework revealed that drawings were focused on the physical appearance of the scientist, and to a lesser extent on the equipment, location and science-related practices that provided the context of a scientist’s role and work. Implications for teacher educators include the need to understand that there is a need to provide tools, like the conceptual framework used in this study, to help prospective teachers to confront and engage with their multidimensional perspectives of scientists in light of the current trends on perceiving and valuing scientists. In addition, teacher educators need to use the conceptual framework, which yields qualitative perspectives about drawings, together with the DAST-C, which yields quantitative measure for drawings, to help prospective teachers to gain a holistic outlook on their drawings of scientists. 相似文献
4.
WANG Mei-yuan LU Yao-bin ZHANG Jin-long 《浙江大学学报(A卷英文版)》2006,7(6):1092-1098
INTRODUCTION Outsourcing offers several advantages, such as enabling existing staff to concentrate on core com-petencies, focusing on achieving key strategic objec-tives, lowering or stabilizing overhead costs, obtain-ing cost competitiveness over the competition, pro-viding flexibility in responding to market conditions, and reducing investments in high technology. Thus software outsourcing is becoming increasingly popular. However, because of the difference between outsourcers and outso… 相似文献
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Understanding curriculum decision‐making through teacher images 总被引：1，自引：0，他引：1
Sue Johnston 《课程研究杂志》2013,45(5):463-471
7.
This paper presents a conceptual analysis for students’ images of graphs and their extension to graphs of two-variable functions. We use the conceptual analysis, based on quantitative and covariational reasoning, to construct a hypothetical learning trajectory (HLT) for how students might generalize their understanding of graphs of one-variable functions to graphs of two-variable functions. To evaluate the viability of this learning trajectory, we use data from two teaching experiments based on tasks intended to support development of the schemes in the HLT. We focus on the schemes that two students developed in these teaching experiments and discuss their relationship to the original HLT. We close by considering the role of covariational reasoning in generalization, consider other ways in which students might come to conceptualize graphs of two-variable functions, and discuss implications for instruction. 相似文献
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ZHU Kai-hua QI Fei-hu JIANG Ren-jie XU Li 《浙江大学学报(A卷英文版)》2007,8(1):63-71
INTRODUCTION Text detection and segmentation from a naturalscene is very useful in many applications. With theincreasing availability of high performance, lowpriced, portable digital imaging devices, the applica-tion of scene text recognition is rapidly expanding. Byusing cameras attached to cellular phones, PDAs, orstandalone digital cameras, we can easily capture thetext occurrences around us, such as street signs, ad-vertisements, traffic warnings or restaurant menus.Automatic recogn… 相似文献
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Andrea Beinicke Katja Pässler Benedikt Hell 《International Journal for Educational and Vocational Guidance》2014,14(2):181-198
The study investigates consequences of eliminating items showing gender-specific differential item functioning (DIF) on the psychometric structure of a standard RIASEC interest inventory. Holland’s hexagonal model was tested for structural invariance using a confirmatory methodological approach (confirmatory factor analysis and randomization tests of hypothesized order relations). Results suggest that eliminating items showing gender-specific DIF had no considerable influence on the instrument’s psychometric structure. Considering DIF as one possibility to improve test fairness when developing interest inventories is discussed. 相似文献
12.
MRI and PET images fusion based on human retina model 总被引：1，自引：0，他引：1
DANESHVAR Sabalan GHASSEMIAN Hassan 《浙江大学学报(A卷英文版)》2007,8(10):1624-1632
The diagnostic potential of brain positron emission tomography (PET) imaging is limited by low spatial resolution. For solving this problem we propose a technique for the fusion of PET and MRI images. This fusion is a trade-off between the spectral information extracted from PET images and the spatial information extracted from high spatial resolution MRI. The proposed method can control this trade-off. To achieve this goal, it is necessary to build a multiscale fusion model, based on the retinal cell photoreceptors model. This paper introduces general prospects of this model, and its application in multispectral medical image fusion. Results showed that the proposed method preserves more spectral features with less spatial distortion. Comparing with hue-intensity-saturation (HIS), discrete wavelet transform (DWT), wavelet-based sharpening and wavelet-à trous transform methods, the best spectral and spatial quality is only achieved simultaneously with the proposed feature-based data fusion method. This method does not require resampling images, which is an advantage over the other methods, and can perform in any aspect ratio between the pixels of MRI and PET images. 相似文献
13.
JIANG Ren-jie QI Fei-hu XU Li WU Guo-rong ZHU Kai-hua 《浙江大学学报(A卷英文版)》2007,8(4):568-574
This paper proposes a learning-based method for text detection and text segmentation in natural scene images. First, the input image is decomposed into multiple connected-components (CCs) by Niblack clustering algorithm. Then all the CCs including text CCs and non-text CCs are verified on their text features by a 2-stage classification module, where most non-text CCs are discarded by an attentional cascade classifier and remaining CCs are further verified by an SVM. All the accepted CCs are output to result in text only binary image. Experiments with many images in different scenes showed satisfactory performance of our proposed method. 相似文献
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INTRODUCTION Image rectification is an important preprocessingstep in many fields, such as computer vision, remotesensing, data fusion and classification; and had beenstudied by many researchers (Hartley, 1999; Fusielloand Trucco, 2000; Dong and Wang, 2000; Chen et al.,2003). There are severe distortions in airborne linearimages because of the ununiformity and turbulence ofthe velocity, the gradient, and the altitude of the air-plane during flight. These data can only be useful ifthey … 相似文献
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Michael D. Piburn Stephen J. Reynolds Carla McAuliffe Debra E. Leedy James P. Birk Julia K. Johnson 《International Journal of Science Education》2013,35(5):513-527
Among the sciences, the practice of geology is especially visual. To assess the role of spatial ability in learning geology, we designed an experiment using: (1) web‐based versions of spatial visualization tests, (2) a geospatial test, and (3) multimedia instructional modules built around QuickTime Virtual Reality movies. Students in control and experimental sections were administered measures of spatial orientation and visualization, as well as a content‐based geospatial examination. All subjects improved significantly in their scores on spatial visualization and the geospatial examination. There was no change in their scores on spatial orientation. A three‐way analysis of variance, with the geospatial examination as the dependent variable, revealed significant main effects favoring the experimental group and a significant interaction between treatment and gender. These results demonstrate that spatial ability can be improved through instruction, that learning of geological content will improve as a result, and that differences in performance between the genders can be eliminated. 相似文献
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In this paper, an electrical resistance tomography（ERT） imaging method is used as a classifier, and then the Dempster-Shafer＇s evidence theory with fuzzy clustering is integrated to improve the ERT image quality. The fuzzy clustering is applied to determining the key mass function, and dealing with the uncertain, incomplete and inconsistent measured imaging data in ERT. The proposed method was applied to images with the same investigated object under eight typical current drive patterns. Experiments were performed on a group of simulations using COMSOL Multiphysics tool and measurements with a piece of porcine lung and a pair of porcine kidneys as test materials. Compared with any single drive pattern, the proposed method can provide images with a spatial resolution of about 10% higher, while the time resolution was almost the same. 相似文献
17.
Robert Watts 《Education 3-13》2019,47(5):534-554
This article reports on a recent study that explored children’s aesthetic preferences. Authors of previous studies in this area have concluded children have a relatively narrow range of preferences based on judgments about their responses to images. In other contexts, researchers have investigated children’s perspectives on their environments and created opportunities for them to take photographs in response to research tasks. This study is the first to draw on both approaches in order to develop a clearer understanding of children’s aesthetic preferences. Fifty-one children in two primary schools were asked to find and photograph images to represent their perceptions of beauty. In order to investigate whether or how children’s environments influenced their preferences, the schools were located in contrasting urban and rural areas. The article explores several contrasts between the two sets of images and offers explanations for these contrasts. It suggests that previous studies may have underestimated the diversity of children’s aesthetic preferences and that social, cultural and environmental factors may explain the differences between children’s aesthetic preferences. The article concludes that both researchers and teachers could adopt similar methods to develop our understanding of children’s perspectives, identities and experiences. 相似文献
18.
Multi-face detection based on downsampling and modified subtractive clustering for color images 总被引：1，自引：0，他引：1
KONG Wan-zeng ZHU Shan-an 《浙江大学学报(A卷英文版)》2007,8(1):72-78
INTRODUCTION Face detection has been widely used in fields such as security, multimedia retrieval, human com-puter interaction, etc. Therefore it becomes one of the most active research areas in computer science. Re-cently, approaches to face detection include neural network (Rowley et al., 1998), boosting (Viola, 2001; Viola and Jones, 2004), template matching (Kim et al.,2000) and skin color (Cai and Goshtasby, 1999; Wang and Yuan, 2001; Soriano et al., 2003), etc. The methods of n… 相似文献
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Sascha Grusche 《International Journal of Science Education》2013,35(8):981-1007
ABSTRACTPrismatic refraction is a classic topic in science education. To investigate how undergraduate students think about prismatic dispersion, and to see how they change their thinking when observing dispersed images, five teaching experiments were done and analysed according to the Model of Educational Reconstruction. For projection through a prism, the students used a ‘split image projection’ conceptualisation. For the view through a prism, this conceptualisation was not fruitful. Based on the observed images, six of seven students changed to a ‘diverted image projection’ conceptualisation. From a comparison between students’ and scientists’ ideas, teaching implications are derived for an image-based approach. 相似文献
20.
Martin Schwichow Simon Christoph William J. Boone Hendrik Härtig 《International Journal of Science Education》2016,38(2):216-237
The so-called control-of-variables strategy (CVS) incorporates the important scientific reasoning skills of designing controlled experiments and interpreting experimental outcomes. As CVS is a prominent component of science standards appropriate assessment instruments are required to measure these scientific reasoning skills and to evaluate the impact of instruction on CVS development. A detailed review of existing CVS instruments suggests that they utilize different, and only a few of the four, critical CVS sub-skills in the item development. This study presents a new CVS assessment instrument (CVS Inventory, CVSI) and investigates the validity of student measures derived from this instrument utilizing Rasch analyses. The results indicate that the CVSI produces reliable and valid student measures with regard to CVS. Furthermore, the results show that the item difficulty depends on the CVS sub-skills utilized in item development, but not on the item content. Accordingly, previous instruments that are restricted to a few CVS sub-skills tend to over- or underestimate students’ CVS skills. In addition, these results indicate that students are able to use CVS as a domain general strategy in multiple content areas. Consequences for science instruction and assessment are discussed. 相似文献