基于ADL小波变换的图像压缩算法

提出一种基于自适应方向提升(ADL)小波变换的图像压缩算法。根据灰度共生矩阵角二阶矩的差异,将图像分割成平坦性不同的分块。对纹理信息较少的块,采用一般提升小波变换以减少变换时间。对纹理信息较多的块,采用方向提升小波以提高变换效果。结合多级树集合分裂编码和算术编码对变换系数和方向信息分别进行编码。实验结果表明,与ADL算法相比,该算法能有效减少方向小波变换时间。     

意会关键词信息取证方法

新型宣传媒介的网络舆情存在大量非法信息。为此,提出一种意会关键词信息取证方法,对中文意会关键词进行定义、分类和量化,给出6种意会关键词提取算法,对提取的证据信息进行完整性处理。实验结果表明,6种算法的提取速度均在毫秒级,查准率和查全率分别达到92%和95%,从而保证在网页舆情监控下非法信息的取证效率。     

Applying a 3D virtual learning environment to facilitate student’s application ability - The case of marketing

In order to understand whether a 3D virtual learning environment is effective in facilitating students’ application ability, we designed a 3D virtual supermarket (3DVS) to help business students to transform abstract class theory into concrete application ability in the real world. In the 3DVS, a virtual customer poses questions to the participant, and then the participant, as a simulated clerk, has to reply to the questions. All of the questions in the 3DVS were developed from marketing mix theory and given a scenario-based form. To understand the effects of the 3DVS, the participants were randomly divided into control group (CG) and experiment group (EG), and only the EG participants were trained with the 3DVS. After examined by pretest and posttest, the results of posttest indicated that the participants of the EG performed significantly better in terms of knowledge application than did those of the CG.     

Are digital natives a myth or reality? University students’ use of digital technologies

This study investigated the extent and nature of university students’ use of digital technologies for learning and socialising. The findings show that students use a limited range of mainly established technologies. Use of collaborative knowledge creation tools, virtual worlds, and social networking sites was low. ‘Digital natives’ and students of a technical discipline (Engineering) used more technology tools when compared to ‘digital immigrants’ and students of a non-technical discipline (Social Work). This relationship may be mediated by the finding that Engineering courses required more intensive and extensive access to technology than Social Work courses. However, the use of technology between these groups is only quantitatively rather than qualitatively different. The study did not find evidence to support popular claims that young people adopt radically different learning styles. Their attitudes to learning appear to be influenced by lecturers’ teaching approaches. Students appear to conform to traditional pedagogies, albeit with minor uses of tools delivering content. The outcomes suggest that although the calls for transformations in education may be legitimate it would be misleading to ground the arguments for such change in students’ shifting patterns of learning and technology use.     

Efficient learning using a virtual learning environment in a university class

This study examines a blended learning setting in an undergraduate course in psychology. A virtual learning environment (VLE) complemented the face-to-face lecture. The usage was voluntary and the VLE was designed to support the learning process of the students. Data from users (N = 80) and non-users (N = 82) from two cohorts were collected. Control variables such as demographical data, attitude towards the learning subject, computer literacy, motivation, learning effort and available infrastructure were captured by means of a self-report. As a learning outcome, the grade in the final exam was included. For the VLE-users, the mean performance in the VLE was taken as a predictor for success in the final exam. Two different groups of VLE-users were observed and classified into ’light and ’heavy’ users. The results showed that among those students who had spent two or more hours per week for pre- and post processing of the lectures, ‘heavy’ VLE-users performed better than non-users in the final exam. Additionally, the ‘heavy’ users’ performance in the VLE was the best predictor for the grade in the final exam. We discuss the results in the context of self-regulated learning competence.     

Design guidelines for Classroom Multiplayer Presential Games (CMPG)

In a Classroom Multiplayer Presential Game (CMPG) peers interact collaboratively with the virtual world and amongst themselves in a shared space. The design of this kind of game, however, is a complex process that must consider instruction strategies, methodology, usability and ludic aspects. This article’s aim is to develop and systematize guidelines for the design of CMPGs. To develop these guidelines we used a three-step process: evaluating an initial implementation of a CMPG and finding its problems; defining guidelines that can help overcome these problems; and redesigning the game based on the guidelines before testing it in a real class scenario to assess how helpful the guidelines were in solving the initial problems.     

Incorporating haptic feedback in simulation for learning physics

The purpose of this study was to investigate the effectiveness of a haptic augmented simulation in learning physics. The results indicate that haptic augmented simulations, both the force and kinesthetic and the purely kinesthetic simulations, were more effective than the equivalent non-haptic simulation in providing perceptual experiences and helping elementary students create multimodal representations of the movements of gears. However, in most cases, force feedback was needed to construct a fully loaded multimodal representation that helps students to comprehend later instruction with less sensory modalities. In addition, the force and kinesthetic simulation was effective in helping to transfer knowledge to new learning situations. These findings suggest that it is important to help elementary students make a solid cognitive grounding with the use of a perceptual anchor.     

The efficiency of identifying timed automata and the power of clocks

We develop theory on the efficiency of identifying (learning) timed automata. In particular, we show that: (i) deterministic timed automata cannot be identified efficiently in the limit from labeled data and (ii) that one-clock deterministic timed automata can be identified efficiently in the limit from labeled data. We prove these results based on the distinguishability of these classes of timed automata. More specifically, we prove that the languages of deterministic timed automata cannot, and that one-clock deterministic timed automata can be distinguished from each other using strings in length bounded by a polynomial. In addition, we provide an algorithm that identifies one-clock deterministic timed automata efficiently from labeled data.Our results have interesting consequences for the power of clocks that are interesting also out of the scope of the identification problem.