Stereoscopy in Static Scientific Imagery in an Informal Education Setting: Does It Matter?

Stereoscopic technology (3D) is rapidly becoming ubiquitous across research, entertainment and informal educational settings. Children of today may grow up never knowing a time when movies, television and video games were not available stereoscopically. Despite this rapid expansion, the field’s understanding of the impact of stereoscopic visualizations on learning is rather limited. Much of the excitement of stereoscopic technology could be due to a novelty effect, which will wear off over time. This study controlled for the novelty factor using a variety of techniques. On the floor of an urban science center, 261 children were shown 12 photographs and visualizations of highly spatial scientific objects and scenes. The images were randomly shown in either traditional (2D) format or in stereoscopic format. The children were asked two questions of each image—one about a spatial property of the image and one about a real-world application of that property. At the end of the test, the child was asked to draw from memory the last image they saw. Results showed no overall significant difference in response to the questions associated with 2D or 3D images. However, children who saw the final slide only in 3D drew more complex representations of the slide than those who did not. Results are discussed through the lenses of cognitive load theory and the effect of novelty on engagement.     

Generating Vocabulary Knowledge for At-Risk Middle School Readers: Contrasting Program Effects and Growth Trajectories

We tested whether urban middle-school students from mostly low-income homes had improved academic vocabulary when they participated in a freely available vocabulary program, Word Generation (WG). To understand how this program may support students at risk for long-term reading difficulty, we examined treatment interactions with baseline achievement on a state standardized test and also differential effects for students with (n = 398) and without (n = 1,395) individualized education plans (IEPs). Students in this unmatched quasi-experiment (5 WG and 4 comparison schools) completed pre- and postvocabulary assessments during the intervention year. We also retested student vocabulary knowledge after summer vacation and the following spring on 11 target words to construct a longitudinally consistent scaled score across 4 waves of data. Growth models show that students experienced summer setback. Although there were no average underlying differences in growth or differences in summer setback for students by baseline achievement, better readers improved more from program participation. IEP status did not predict differential benefits of program participation, and students with IEPs maintained gains associated with participation in WG; however, participation in the program did not change underlying growth trajectories favoring students who did not have IEPs.     

Digital storytelling and the nature of knowledge

While storytelling pedagogy presents novel perspectives and affordances to educators, a fundamental question that bears attention is the match between storytelling pedagogy and the nature of knowledge. Quite simply, the problem may be posed thus: is storytelling the optimum means for teaching all forms of knowledge? While rather obvious matches occur for knowledge in the social science, humanities, languages and literacy education, would storytelling pedagogy ‘work’ for the natural sciences, technology, engineering and mathematics classrooms? If so, what may be optimum means to integrate storytelling instruction in these latter kinds of classrooms? In this study, we report on the results of an implementation of digital storytelling in a grade five science classroom. Using what we termed the ‘edu-tainment’ approach, we asked students to design a digital story that communicated a scientific concept embedded within the narrative structure—characters within the narrative would experience the effects of the concept, the quality of the story being proxy indicators of students’ understanding of the scientific concept. We propose that this pedagogical strategy presents a strong challenge to discern students’ understanding, and we also discuss the effect of knowledge forms on the success of this pedagogy.     

Do Latino Youth Really Want to Get Pregnant?: Assessing Pregnancy Wantedness

Despite recent declines, Latinas bear a disproportionate burden of teen births. Understanding social, cultural, and demographic factors underlying pregnancy desire among Latino adolescents is needed to design effective teen pregnancy prevention interventions.

A questionnaire was completed by 794 Latino youth including a “pregnancy wantedness scale” (PWS) to assess attitudes toward an early pregnancy and socio-demographic variables. Regression analyses examined the association between these variables and PWS score. PWS scores for all groups were below but near the midpoint, suggesting ambivalence toward an early pregnancy. Being female, older, acculturated, using hormonal contraception, living with parents, and having an educated mother were significantly associated with lower PWS scores, but impacted youth differently depending on their sex and sexual experience. Multi-component Latino teen pregnancy prevention strategies should address behavioral and attitudinal differences based on sex and sexual experience and acknowledge the contribution of social determinants on pregnancy intentions.     

Participation patterns of Korean adolescents in school-based career exploration activities

Variations in the school-based career exploration activities of Korean high school students were examined. Data represented 5,227 Korean adolescents in Grade 11 contained in the Korean Education Longitudinal Study of 2005, a nationally representative longitudinal database administered by the Korean Educational Development Institute. Latent class analysis identified four classes or approaches reflecting some combination of school availability and student use of career-related activities, including minimal-, limited-, moderate-, and high-activity groups. Multiple-group analysis revealed that curriculum track (i.e., vocational or academic emphasis) was an important determinant in classification.     

蚕桑文化在小学美术教学中的开发与实施研究

积极开发和合理利用本土文化资源是小学美术新课程实施的重要组成部分,蚕桑文化作为地方文化资源,它的开发与利用对学生的成长和民族优秀文化的传承具有重要意义。在小学美术教学中,开发和实施凸显特色的本土蚕桑文化资源,不仅要注重内容的收集和选择,而且要注重美术课堂教学和实践活动的结合。     

阅读教学模式在英语专业阅读课中的应用

教学模式是一种相对稳定而又简单的教学结构,采用合适的教学模式有利于提高教学质量,培养学生独立自主学习的能力。本文研究了国内外主要的阅读教学模式,并列举出我国英语专业阅读课目前所采用的教学模式,分析其存在的一些问题。     

The PS-BCJR Algorithm for Joint Frequency Synchronization and Data Decoding in TCM systems

This study proposes a per-survivor based BCJR algorthm for joint frequency synchronization and data decoding in trellis coded modulation (TCM) systems. The proposed algorithm uses two probing signals and a carrier frequency offset (CFO) tracker to calculate the modified gamma factor involved in the BCJR algorithm. To track the CFO, a state-time process recursively updates the CFO tracker using the soft-information provided by the modified gamma factor. The state-time process consists of a state-process and a time-process. The state-process takes advantage of the state-diversity in the TCM signals to choose the most probable CFO update corresponding to the state with the maximal modified gamma factor. Based on this CFO value, and in conjunction with the tentatively selected probing signals, the succeeding time-process can iteratively track the CFO using the trellis structure of the TCM signals. This study also develops a least-square-linear-fitting (LSLF) approach based on the CFO trace to dynamically adjust the step-size for the CFO tracker. Computer simulations show that unlike the conventional augmented a posteriori probability (A²P²) method having a small CFO tracking range, the proposed approach can handle a significantly larger CFO because of its ML-based CFO estimate. In addition, the proposed LSLF step-size determination ensures the PS-BCJR a higher accuracy in CFO estimation than the A²P².     

Estimation fusion of nonlinear cost functions with application to multisensory Kalman filtering

This paper focuses on four fusion algorithms for the estimation of nonlinear cost function (NCF) in a multisensory environment. In multisensory filtering and control problems, NCF represents a nonlinear multivariate functional of state variables, which can indicate useful information of the target systems for automatic control. To estimate the NCF using multisensory information, we propose one centralized and three decentralized estimation fusion algorithms. For multivariate polynomial NCFs, we propose a simple closed-form computation procedure. For general NCFs, the most popular procedure for the evaluation of their estimates is based on the unscented transformation. The effectiveness and estimation accuracy of the proposed fusion algorithms are demonstrated with theoretical and numerical examples.     

General solution to the losses estimation for multifractal traffic

In this work, we present a new approach for loss probability estimation in a single server link. We show how to get the estimates analytically once we assume multifractal input traffic. In order to make the estimation procedure numerically tractable without losing the accuracy, we propose the use of a Gaussian mixture model to represent the heavy tail distribution of modern network traffic trace. The adopted evaluation procedure is based on two performance measures: empirical traffic arrival load distribution and loss probability at connection. Extensive experimental tests validate the efficiency and accuracy of the proposed loss probability estimation approach against the results obtained by simulations with real traffic and by comparing with other multifractal approaches suggested in the literature.