Image copy-move forgery detection using SURF in opponent color space

Most existing methods for image copy-move forgery detection(CMFD)operate on grayscale images. Although the keypoint-based methods have the advantages of strong robustness and low computational cost, they cannot identify the flat duplicated regions without reliable extracted features. In this paper, we propose a new CMFD method by using speeded-up robust feature(SURF)in the opponent color space. Our method starts by converting the inspected image from RGB to the opponent color space. The color gradient per pixel is calculated and taken as the work space for SURF to extract the keypoints. The matched keypoints are clustered and their geometric transformations are estimated. Finally, the false matches are removed. Experimental results show that the proposed technique can effectively expose the duplicated regions with various transformations, even when the duplication regions are flat.     

An examination of the relationship between Facebook groups attached to university courses and student engagement

Educators and researchers are increasingly interested in the benefits of using Facebook groups attached to university courses, largely around connectedness, engagement and sense of belonging. However, thus far, there have been no broad-scale investigations on the potential outcomes of course-attached Facebook groups. The current study used both within- and between-group analyses on 471 participants, in order to investigate whether courses with an attached official or unofficial Facebook group was related to increased student engagement (in the categories of relationships with faculty members, peer relationships, behavioural engagement, cognitive engagement, valuing and a sense of belonging) and degree identity compared to courses without Facebook groups. Results indicated that students reported interacting more with unofficial than official Facebook groups. Courses with an official Facebook group had significantly greater staff connectedness compared to courses without an official Facebook group, while courses with either an official or unofficial Facebook group had a significantly higher peer relationships compared to courses without any Facebook group. Students with either an official or unofficial Facebook group had a significantly higher sense of belonging. Though students with either an official or unofficial Facebook group reported higher degree identity, this may be primarily due to the unofficial, rather than official Facebook groups; this difference may only exist in the unofficial, but not the official Facebook groups.     

Static and dynamic behavior of concrete slabs reinforced with chemically reactive enamel-coated steel bars and fibers

In this study, the effect of steel fibers coated with chemically reactive enamel (CRE) on the system response of concrete structures with reinforcing bars has been investigated for the first time. In particular, the ultimate strength, ductility, and failure mechanism of 24 reinforced concrete slabs were experimentally characterized under static and blast loads. CRE coating applied on steel bars reduced the crater area of slabs under blast loads by up to 20%; it slightly increased the strength of slabs and significantly reduced the strength degradation of slabs when increasingly deflected under static loads, making the slabs more ductile. CRE coating applied on steel fibers increased the strength of slabs by up to 16% under static loads. The influence of CRE coating applied on both steel fibers and bars may be taken into account by introducing a coating factor in the range of 0.57<β<1.0 in the American Concrete Institute (ACI) development length equation.     

Analysis of FIFA referees and assistant referees’ motivational factors towards the Multimedia Teaching Materials

The aim of our study is to improve the understanding of the different behavioral intentions of referees and assistant referees in different FIFA (International Federation of Association Football) confederations towards Multimedia Teaching Materials as learning tools. To achieve this goal, we carry out a survey of 214 elite referees and assistant referees and we propose a research model with the variables perceived usefulness, perceived ease of use, perceived enjoyment, perceived self-efficacy, multimedia instruction, previous experience with technology and self-paced learning. These variables were taken from previous educational technology research. Among these models we mainly take into account the Technology Acceptance Model, the Motivational Model and the Social Cognitive Theory. To assess the relationships between the constructs, we develop an analysis based on a Structural Equation Modeling (SEM), specifically Partial Least Squares (PLS). The results of this study confirm that referees and assistant referees are willing to use Multimedia Teaching Materials to assist them in their learning activities as long as they perceive the materials to be useful, enjoyable and easy to use and whenever the course contents are multimedia.     

What are Middle School Students Talking About During Clicker Questions? Characterizing Small-Group Conversations Mediated by Classroom Response Systems

There is a growing interest in using classroom response systems or clickers in science classrooms at both the university and K-12 levels. Typically, when instructors use this technology, students are asked to answer and discuss clicker questions with their peers. The existing literature on using clickers at the K-12 level has largely focused on the efficacy of clicker implementation, with few studies investigating collaboration and discourse among students. To expand on this work, we investigated the question: Does clicker use promote productive peer discussion among middle school science students? Specifically, we collected data from middle school students in a physical science course. Students were asked to answer a clicker question individually, discuss the question with their peers, answer the same question again, and then subsequently answer a new matched-pair question individually. We audio recorded the peer conversations to characterize the nature of the student discourse. To analyze these conversations, we used a grounded analysis approach and drew on literature about collaborative knowledge co-construction. The analysis of the conversations revealed that middle school students talked about science content and collaboratively discussed ideas. Furthermore, the majority of conversations, both ones that positively and negatively impacted student performance, contained evidence of collaborative knowledge co-construction.     

Counselling Families Affected by Socio-Political Factors and Economic Hardships

This article discusses the contemporary stressful situations faced by families in many parts of the developing world due to war and armed conflicts and displacement of families due to mega development projects. While it highlights that both lead to impoverishment of people, it points out that the basic differences in the situation of families facing war and armed conflicts and displacement due to development projects, and outlines a few broad contexts of counselling when working with victims of war and displaces of development projects.     

The moderating influence of instructional intensity and word type on the acquisition of academic vocabulary in young English language learners

This study used a within-subjects design to explore two instructional conditions for developing vocabulary in second-grade Spanish-speaking English learners (ELs)—extended instruction and embedded instruction implemented during shared interactive reading. Words assigned to the extended condition were directly taught using a multifaceted approach that included visuals, bilingual definitions, examples, spelling, and partner-talk about the words’ meaning. Words assigned to the embedded condition were taught solely through brief definitions to embedded text, writing activities, and songs. In the control condition students heard the target words read aloud during shared interactive reading but without definitions or direct instruction. The study also explored the interaction between instructional condition and word type. Four types of words—abstract cognates, abstract noncognates, concrete cognates, and concrete noncognates—were randomly assigned to each condition. Nine teachers in four schools and 187 second-grade ELs participated in this within-subjects intervention, which took place in transitional bilingual classrooms. Findings indicated that across all word types, both extended and embedded instruction were more effective than the control condition in helping ELs acquire vocabulary. Findings also indicated that extended instruction was more effective then embedded instruction for all word types except concrete cognates suggesting that these young Spanish-speaking ELs were advantaged by word knowledge in their home language. Finally, while embedded instruction was less effective than extended instruction, it was much more effective than a control condition. Embedded instruction takes significantly less preparation and instructional time than extended instruction, offering teachers a practical way to teach more vocabulary to ELs.