Measures for investigating the contextual modulation of information transmission

The aim of this paper is to show how information theoretic measures can be used to analyse and interpret the results of psychophysical experiments designed to search for conditions under which information from one source modulates the transmission of information from another source. We therefore use measures of mutual and conditional information to analyse systems with two inputs. The information transmitted by such a system can be split into three components depending on whether it is shared between the two inputs or is specific to each. We are concerned here with distinguishing systems that use one input to modulate transmission of information about the other from systems that simply add both inputs, and show how the three components provide evidence for distinguishing between additive and modulatory effects. We also report numerical simulations of the sampling biasses and variances of these measures as a function of the sample size and propose minimum sample sizes that should be used to overcome the bias.     

A video monitoring technique for investigating computer-based learning programs

Few studies of computer-based learning materials concentrate upon the learner-computer interaction. Fewer studies have focused on the way children learn science using computer-based learning programs. The studies that have been done employed observational methods. A video monitoring technique, which produces a synchronized record of the computer output and the children's use of the computer program is described. The technique affords a greater precision of data than observational techniques. A study which employed this technique is described.     

Designing collaborative,constructionist and contextual applications for handheld devices

This paper explores current applications for handheld devices and questions which of these make full use of the unique attributes of handheld devices in order to facilitate learning in a pedagogically sensible manner. In order to do so, the paper presents a functional framework which analyses handheld application in relation to their use as well as the pedagogical underpinning, if any, that informs their development. Our framework currently consists of seven distinct categories of application, which we term: administrative, referential, interactive, microworld, data collection, location aware and collaborative. We argue that three categories, namely data collection, location aware and collaborative, are particularly suited to learning with handheld devices when they are informed by collaborative, contextual and constructionist learning theories. Furthermore, we contend that applications of the type just outlined deserve further research since they are not attempting to replicate, or even augment, existing learning scenarios but rather they try to create new learning opportunities which would not be possible without (mobile) technology. Finally, the authors introduce a number of applications and learning scenarios that they have developed for handheld devices and explain their position within the framework.     

Designing on-site: Facilitating participatory contextual architecture with mobile phones

Some movements within modern architecture particularly emphasise the importance of matching buildings to their surroundings. However, practicing such “contextual architecture” is highly challenging and typically not something the future inhabitants of a building are well equipped for participating in. This paper explores the potentials of using mobile phone technology for facilitating such client participation in the parts of an architecture process that take place on the building site. For this we introduce ArchiLens, a mobile system for interactive on-site 3D visualisation of houses, and findings from a field study with 40 participants in the process of building or modifying their home. The study showed that using the system helped evoke people’s imagination of the look and feel of their future house, and envision it in context. This enabled them to participate more closely in the design process on-site by iteratively reviewing design alternatives and exploring, for example, other placements and materials.     

The use of contextual cues to improve warning symbol comprehension: making the connection for older adults

This study teased apart the effects of comprehensibility and complexity on older adults' comprehension of warning symbols by manipulating the relevance of additional information in further refining the meaning of the symbol. Symbols were systematically altered such that increased visual complexity (in the form of contextual cues) resulted in increased comprehensibility. One hundred older adults, aged 50–71 years, were tested on their comprehension of these symbols before and after training. High comprehensibility–complexity symbols were found to be better understood than low- or medium-comprehensibility–complexity symbols and the effectiveness of the contextual cues varied as a function of training. Therefore, the nature of additional detail determines whether increased complexity is detrimental or beneficial to older adults' comprehension – if the additional details provide ‘cues to knowledge’, older adults' comprehension improves as a result of the increased complexity. However, some cues may require training in order to be effective.

Practitioner Summary: Research suggests that older adults have greater difficulty in understanding more complex symbols. However, we found that when the complexity of symbols was increased through the addition of contextual cues, older adults' comprehension actually improved. Contextual cues aid older adults in making the connection between the symbol and its referent.     

Lovers' box: Designing for reflection within romantic relationships

We present the Lovers' box, a digital artefact designed to engage romantic couples in reflections on their relationship. By adopting perspectives from social psychology and interaction design, the work examines the role of reflection through the use of a non-traditional digital artefact that acts as a site for enduring attachments of personal emotional significance. To this end, we respond to previous research work on reflection through design, in the development of four Lovers' boxes whose purposes and meanings are completed through reflections both by romantic couples and their integration in everyday lives. A field study was conducted involving five couples in new relationships who were asked to exchange video messages (co-created with a digital media artist) using the Lovers' box over a period of five weeks. Our findings demonstrated: (1) that the creation, exchange and display of messages embedded in the digital artefact served as both mirrors and sources for reflection concerning couples' relationships; (2) the rich manner in which the Lovers' box became meaningful to participants, as they perceived it as keepsake or digital storybook of their meaningful experiences, experienced it as an enjoyable shared hobby with their partner and saw it as providing them a snapshot into the beloved person's mind and thoughts; and (3) how the potential for new castings of digital artefacts might support our personal and emotional lives.     

Lost in translation: investigating the ambiguity of availability cues in an online media space

In this paper we present a longitudinal study of an online media space addressing the question of how availability is managed in an interaction-intensive organization. We relied on three different data collection techniques and analysed our data in relation to three different work modes. During this study we participated in an online media space, for approximately six months making spot checks and observing the population from which ten subjects were selected for interviews. Our results show how techniques and strategies for availability management are developed and continuously adapted to a shared common ground. Further, our results show how having the communication channel open, and regulating availability on a social level instead of on a solely technical level, has the advantage of better coping with the ever-changing dynamics in group works. Finally, we show that there exists an ambiguity of availability cues in online media spaces that is smoothly handled by individuals.     

A video recording and viewing protocol for student group presentations: Assisting self-assessment through a Wiki environment

The purpose of this research was to firstly develop a protocol for video recording student group oral presentations, for later viewing and self-assessment by student group members. Secondly, evaluations of students' experiences of this process were undertaken to determine if this self-assessment method was a positive experience for them in gaining insights into the quality of their group's presentation. Participants were students undertaking a first year course in a bachelor of business degree within an Australian university. Students were surveyed twice, once prior to group formation to determine their previous oral group presentation experiences and then after viewing their presentations. Data from survey items assessing students' perspectives on the utility of viewing their video presentations, within their group Wikis, revealed that watching the video of their group presentation was an effective method of feedback and could improve both group and individual performance in the future. Further, content analysis of open ended survey questions and focus groups identified that students were highly engaged in the activity and after reviewing and reflecting on their video recording had deeper insights and raised awarenesses of making group presentations. Students identified that this experience would benefit any future group oral presentations they made.     

Correction to: Scene Walk: a non‑photorealistic viewing tool for first‑person video

Virtual Reality - A correction to this paper has been published: https://doi.org/10.1007/s10055-021-00545-y     

Stereo using monocular cues within the tensor voting framework

We address the fundamental problem of matching in two static images. The remaining challenges are related to occlusion and lack of texture. Our approach addresses these difficulties within a perceptual organization framework, considering both binocular and monocular cues. Initially, matching candidates for all pixels are generated by a combination of matching techniques. The matching candidates are then embedded in disparity space, where perceptual organization takes place in 3D neighborhoods and, thus, does not suffer from problems associated with scanline or image neighborhoods. The assumption is that correct matches produce salient, coherent surfaces, while wrong ones do not. Matching candidates that are consistent with the surfaces are kept and grouped into smooth layers. Thus, we achieve surface segmentation based on geometric and not photometric properties. Surface overextensions, which are due to occlusion, can be corrected by removing matches whose projections are not consistent in color with their neighbors of the same surface in both images. Finally, the projections of the refined surfaces on both images are used to obtain disparity hypotheses for unmatched pixels. The final disparities are selected after a second tensor voting stage, during which information is propagated from more reliable pixels to less reliable ones. We present results on widely used benchmark stereo pairs.     

传感网环境下视频传感器在线规划

针对视频传感器观测被动的问题,结合视频传感器和传感网的特点,设计了传感网环境下视频传感器在线规划框架。该框架采用面向服务的体系架构（ SOA）,包含资源层、资源服务层、规划服务层和应用层四个层,各层之间采用标准的网络通信协议进行通信。实现了视频传感器在线规划原型系统,并以视频监控签到为应用场景进行了在线规划实验。实验结果表明：该框架对于实现视频传感器主动和按需观测是可行且有效的。     

Designing a collector overlay architecture for fault diagnosis in video networks

To prevent subscriber churn, network service providers of VoD, SDV and IPTV have a pressing need to pro-actively detect, isolate and fix outages within an access network. Network induced degradations prove to be detrimental for streaming applications. This typically leads to a poor quality of experience (QoE) for subscribers. By monitoring key functional points of the access network for traces of degradation, service providers can devise mechanisms to mitigate the problem.In this work we propose a hierarchy of exporters, collectors and ANCON (ANalysis and CONtrol) nodes that can semi-autonomously monitor, detect and isolate impairments within an access network. Exporters on the data plane gather and disseminate statistics for individual subnets, which are streamed onto “collector” nodes on an orthogonal plane. Collector nodes aggregate traffic from various exporters, and stream them onto the root of the tree (ANCON). With an even placement of exporters, root cause analysis can now take the granularity of loss rates or delay rates in individual segments or subnets of an access network. As an extension to our architecture, we show that the overlay can support instrumentations of quality evaluation for streaming video. As an example, we use a simple MOS plugin that is in part an extension of the ITU-T Erlang model to predict the quality of a video stream much before it reaches the end user. We show that our overlay can support a wide variety of quality evaluation metrics. Through extensive simulations and an implementation, we discuss issues of engineering such an overlay, isolating impairments in access networks, instrumenting MOS plugins and predicting video quality of multimedia streams in transit.     

Neuralbase model for detection and recognition of technological situations within the scope of data mining strategy

The article considers the problem of detection and recognition of technological events and oil reception-delivery object states on the base of the analysis of the time-series describing the processes on the object is. Step-by-step, the tasks of preprocessing raw data, segmenting time-series, data clusterization and classification as well as neural net committee building for the object condition diagnosing within the scope of Data Mining strategy are resolved.     

LiveSync: deformed viewing spheres for knowledge-based navigation

Although real-time interactive volume rendering is available even for very large data sets, this visualization method is used quite rarely in the clinical practice. We suspect this is because it is very complicated and time consuming to adjust the parameters to achieve meaningful results. The clinician has to take care of the appropriate viewpoint, zooming, transfer function setup, clipping planes and other parameters. Because of this, most often only 2D slices of the data set are examined. Our work introduces LiveSync, a new concept to synchronize 2D slice views and volumetric views of medical data sets. Through intuitive picking actions on the slice, the users define the anatomical structures they are interested in. The 3D volumetric view is updated automatically with the goal that the users are provided with expressive result images. To achieve this live synchronization we use a minimal set of derived information without the need for segmented data sets or data-specific pre-computations. The components we consider are the picked point, slice view zoom, patient orientation, viewpoint history, local object shape and visibility. We introduce deformed viewing spheres which encode the viewpoint quality for the components. A combination of these deformed viewing spheres is used to estimate a good viewpoint. Our system provides the physician with synchronized views which help to gain deeper insight into the medical data with minimal user interaction.     

计算机网络犯罪侦查技术及策略研究

计算机网络犯罪是一种犯罪的新形态,网络犯罪必须在特定的空间内实施,与传统犯罪形式相比,不会留下物质性痕迹、犯罪目的与动机的特殊性、犯罪证据的即时性和不可物化性,及其犯罪具有极高的隐蔽性,这些使得计算机网络犯罪行为不易被发现、识别和侦破。该文结合计算机网络技术应用与犯罪案件的侦查,对计算机网络犯罪的形态、计算机网络犯罪案件的侦查技术和侦查策略进行了详细的阐述。     

Opening up innovation: the impact of contextual factors on the co-creation of IT-enabled value adding services within the manufacturing industry

This paper examines the contextual factors that influenced an open innovation project failure. To this end the paper adds to the discussion on open innovation in non high-tech settings and highlights the importance of contextual factors as determinants of success or failure within the open innovation paradigm. It is based on a case study performed at PowerDrive, a manufacturer of hydraulic drive systems, and three of its customers, and follows their attempt to co-create new value-adding services through the innovative use of information technology in the form of a remote monitoring system. The study shows that open innovation project success cannot be measured only in terms of coherence with set targets of quality, time, and costs, but also has to include the creation of mutual value and the development of trust and strong inter-organizational relationships. Furthermore, the role and character of information technology has to be considered and accounted for and the social context made explicit. By managing the value creation process, the value proposal stands a better chance of indeed providing value.     

Event-driven video adaptation: A powerful tool for industrial video supervision

Efficient video content adaptation requires techniques for content analysis and understanding as well as the development of appropriate mechanisms for content scaling in terms of the network properties, terminal devices characteristics and users’ preferences. This is particularly evident in industrial surveillance applications, due to the huge amount of data needed to be stored, delivered and handled. In this paper, we address both issues by incorporating (a) computer vision tools that allows efficient tracking of salient visual objects for long time regardless of the dynamics of the visual environment –via a self initialized tracking algorithm—and (b) an adaptive optimal rate distortion scheme able to allocate different priorities for each detected video object with respect to users’ needs, network platforms capabilities and terminal characteristics. The self initialized tracker firstly appropriately describes visual content, secondly incorporates adaptive mechanisms for automatically update the tracker to adjust to the current conditions and thirdly includes an efficient decision mechanism that estimates the time instances in which adaptation should be activated. For the rate distortion algorithm, an optimal adaptive framework is adopted which is capable of allocating the desired quality to objects of users’ interest without violating the target bit rate of the sequence. The Wavelet Packet Transform (WPT) is adopted towards this purpose. The advantage of the WPT is that it localizes the frequency components of each video object and therefore it offers additionally content adaptability according to video object texture coding. The WPT tree is transmitted only at the first frame of each shot and thus dew bits are required for its encoding. Experimental results and comparisons with other approaches are presented to illustrate the good performance of the proposed architecture. The results cover real-world and complex industrial environments.     

Real-time video watermarking system on the compressed domain for high-definition video contents: Practical issues

Everyday, we encounter high-quality multimedia contents from HDTV broadcasting, DVD, and high-speed Internet services. These contents are, unhappily, processed and distributed without protection. This paper proposes a practical video watermarking technique on the compressed domain that is real-time and robust against video processing attacks. In particular, we focus on video processing that is commonly used in practice such as downscaling resolution, framerate changing, and transcoding. Most previous watermarking algorithms are unable to survive when these processings are strong or composite. We extract low frequency coefficients of frames in fast by partly decoding videos and apply a quantization index modulation scheme to embed and detect the watermark. On an Intel architecture computer, we implement a prototype system and measure performance against video processing attacks frequently occur in the real world. Simulation results show that our video watermarking system satisfies real-time requirements and is robust to protect the copyright of HD video contents.