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1.
Ubiquitous computing environments stretch the requirements of traditional infrastructures used to facilitate the development of applications. Activities are often supported by collections of applications, some of which are automatically launched with little or no human intervention. This task-driven environment challenges existing application construction and data management techniques. In this paper, we describe a file system that organises application data based on contextual information, imports user data based on its physical presence, and supports format conversions to accommodate device context. We describe several applications that we have developed within our ubiquitous computing infrastructure and show how they leverage the novel features of our file system to simplify their complexity. 相似文献
2.
The European Union co-funded COMUNICAR (communication multimedia unit inside car) project designed and developed an integrated multimedia human–machine interface (HMI) able to manage a wide variety of driver information systems (from entertainment to safety). COMUNICAR proposed an innovative information provision paradigm, in which the on-vehicle HMI is able to tailor the delivery of the information in real time according to the actual driving context and the drivers workload. COMUNICAR adopted a user-centred design process involving an iterative development based on extensive user tests since the early phases of the project. This approach was particularly useful to define and improve the layout of the user interface and specify the rules that decide the scheduling and the modalities of the delivery of the information messages to the driver. This paper introduces the COMUNICAR concept and the user-centred flow of design. Then, a concrete case of user-test driven, iterative improvement of a systems functionality is presented. We also briefly describe two software tools that we have designed to enhance the development process in a user-centred perspective. Finally, the future evolution of the concept of smart and safe information scheduling is sketched and discussed. 相似文献
3.
This paper describes security and privacy issues for multimedia database management systems. Multimedia data includes text,
images, audio and video. It describes access control for multimedia database management systems and describes security policies
and security architectures for such systems. Privacy problems that result from multimedia data mining are also discussed.
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4.
As computer infrastructures become more complex, security models must provide means to handle more flexible and dynamic requirements.
In the Organization Based Access Control (OrBAC) model, it is possible to express such requirements using the notion of context.
In OrBAC, each security rule (permission, prohibition, obligation or dispensation) only applies in a given context. A context
is viewed as an extra condition that must be satisfied to activate a given security rule. In this paper, we present a taxonomy
of different types of context and investigate the data the information system must manage in order to deal with these different
contexts. We then explain how to model and evaluate them in the OrBAC model.
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5.
The complexity of group dynamics occurring in small group interactions often hinders the performance of teams. The availability
of rich multimodal information about what is going on during the meeting makes it possible to explore the possibility of providing
support to dysfunctional teams from facilitation to training sessions addressing both the individuals and the group as a whole.
A necessary step in this direction is that of capturing and understanding group dynamics. In this paper, we discuss a particular
scenario, in which meeting participants receive multimedia feedback on their relational behaviour, as a first step towards
increasing self-awareness. We describe the background and the motivation for a coding scheme for annotating meeting recordings
partially inspired by the Bales’ Interaction Process Analysis. This coding scheme was aimed at identifying suitable observable
behavioural sequences. The study is complemented with an experimental investigation on the acceptability of such a service.
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6.
The Stanford Event Heap has been shown to provide appropriate support for constructing interactive workspace applications.
Given this success it is natural to consider the Event Heap as a platform to support other classes of Ubiquitous Computing
applications. In this paper we argue that the distributed, spontaneous nature of these applications places additional demands
on the Event Heap that require extensions to both the engineering and API. Suitable extensions are described and their use
to support a typical Ubicomp application is discussed.
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7.
3D computer graphics have been an important feature in games development since it was first introduced in the early 80s and
there is no doubt that 3D based content is often viewed as more attractive in games than the more abstract 2D graphics. Many
games publishers are keen to leverage their success in the console market into the mobile phone platform. However, the resource
constraints of mobile phones and the fragmented nature of the environment present considerable challenges for games developers.
In this paper we consider some of the current constraints together with current and, probable, future developments both in
the software and hardware of mobile phones. As part of this process we benchmark some of the latest and most prevalent software
and hardware devices to ascertain both the quality of the graphics produced and the effects upon battery life. Whilst our
test results highlight that the current market does indeed present challenges, our research into the future developments highlights
the fact we are approaching greater standardization, which will be an important factor for the successful development of 3D
mobile games.
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8.
We present an approach to connect multiple remote environments over web for natural interaction among people and objects.
Focus of current communication and telepresence systems severely restrict user affordances in terms of movement, interaction,
peripheral vision, spatio-semantic integrity and even information flow. These systems allow information transfer rather than
experiential interaction. We propose Environment-to-Environment (E2E) as a new paradigm for communication which allows users
to interact in natural manner using text, audio, and video by connecting environments. Each Environment is instrumented using
as many different types of sensors as may be required to detect presence and activity of objects. This object position and
activity information is used by a scalable event-based multimodal information system called EventServer to share the appropriate
experiential information with other environments as well as to present incoming multimedia information on right displays and
speakers. This paper describes the design principles for E2E communication, discusses system architecture, and gives our experience
in implementing prototypes of such systems in telemedicine and office collaboration applications. We also discuss the research
challenges and a road-map for creating more sophisticated E2E applications in near future.
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9.
Quantitative usability requirements are a critical but challenging, and hence an often neglected aspect of a usability engineering process. A case study is described where quantitative usability requirements played a key role in the development of a new user interface of a mobile phone. Within the practical constraints of the project, existing methods for determining usability requirements and evaluating the extent to which these are met, could not be applied as such, therefore tailored methods had to be developed. These methods and their applications are discussed. 相似文献
10.
We present a study of using camera-phones and visual-tags to access mobile services. Firstly, a user-experience study is described in which participants were both observed learning to interact with a prototype mobile service and interviewed
about their experiences. Secondly, a pointing-device task is presented in which quantitative data was gathered regarding the speed and accuracy with which participants aimed and clicked
on visual-tags using camera-phones. We found that participants’ attitudes to visual-tag-based applications were broadly positive,
although they had several important reservations about camera-phone technology more generally. Data from our pointing-device
task demonstrated that novice users were able to aim and click on visual-tags quickly (well under 3 s per pointing-device
trial on average) and accurately (almost all meeting our defined speed/accuracy tradeoff of 6% error-rate). Based on our findings,
design lessons for camera-phone and visual-tag applications are presented.
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11.
We present XFlavor, a framework for providing XML representation of multimedia data. XFlavor can be used to convert multimedia
data back and forth between binary and XML representations. Compared to bitstreams, XML documents are easier to access and
manipulate, and consequently, the development of multimedia processing software is greatly facilitated, as one generic XML
parser can be used to read and write different types of data in XML form.
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12.
PECOLE (Peer-to-pEer COLlaborative Environment) is a fully decentralized multimedia collaborative environment that supports
a wide range of collaborative multimedia applications, including chat, shared browsing, shared telepointer, multipoint-to-multipoint
audio/video conferencing and multilingual collaboration. PECOLE can intelligently run on very constrained resources, is highly
resilient, scalable and does not rely on dedicated servers. Instead, PECOLE is built upon a Peer-to-Peer (P2P) overlay network,
using SUN’s JXTA framework and SWT technology. In this paper, we present the architecture and implementation of PECOLE with
the performance results of the tests we conducted.
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13.
Querying live media streams is a challenging problem that is becoming an essential requirement in a growing number of applications.
Research in multimedia information systems has addressed and made good progress in dealing with archived data. Meanwhile,
research in stream databases has received significant attention for querying alphanumeric symbolic streams. The lack of a
data model capable of representing different multimedia data in a declarative way, hiding the media heterogeneity and providing
reasonable abstractions for querying live multimedia streams poses the challenge of how to make the best use of data in video,
audio and other media sources for various applications. In this paper we propose a system that enables directly capturing
media streams from sensors and automatically generating more meaningful feature streams that can be queried by a data stream
processor. The system provides an effective combination between extendible digital processing techniques and general data
stream management research. Together with other query techniques developed in related data stream management streams, our
system can be used in those application areas where multifarious live media senors are deployed for surveillance, disaster
response, live conferencing, telepresence, etc.
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14.
There are only a few ethical regulations that deal explicitly with robots, in contrast to a vast number of regulations, which
may be applied. We will focus on ethical issues with regard to “responsibility and autonomous robots”, “machines as a replacement
for humans”, and “tele-presence”. Furthermore we will examine examples from special fields of application (medicine and healthcare,
armed forces, and entertainment). We do not claim to present a complete list of ethical issue nor of regulations in the field
of robotics, but we will demonstrate that there are legal challenges with regard to these issues.
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15.
This paper is derived from a keynote address given that the DMS-03 meeting. It chronicles the need and development of next
generation networks (NGN) in the United States. Specific organizational examples are derived from the Internet2-Abilene Network.
The technical characteristics of a next generation network versus the Internet are discussed. Examples are given from the
point of view of the need for a quality of service based network to deliver distributed multimedia healthcare information
to the point of need. The concepts of network trust and of a network based scalable information infrastructure for the reliable
delivery of distributed multimedia information is also introduced.
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16.
This paper describes the simulated car racing competition that was arranged as part of the 2007 IEEE Congress on Evolutionary
Computation. Both the game that was used as the domain for the competition, the controllers submitted as entries to the competition
and its results are presented. With this paper, we hope to provide some insight into the efficacy of various computational
intelligence methods on a well-defined game task, as well as an example of one way of running a competition. In the process,
we provide a set of reference results for those who wish to use the simplerace game to benchmark their own algorithms. The paper is co-authored by the organizers and participants of the competition.
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17.
The paper reflects on the unique experience of social and technological development in Lithuania since the regaining of independence
as a newly reshaped society constructing a distinctive competitive IST-based model at global level. This has presented Lithuanian
pattern of how to integrate different experiences and relations between generations in implementing complex information society
approaches. The resulting programme in general is linked to the Lisbon objectives of the European Union. The experience of
transitional countries in Europe, each different but facing some common problems, may be useful to developing countries in
Africa.
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18.
Many environmental, scientific, technical or medical database applications require effective and efficient mining of time
series, sequences or trajectories of measurements taken at different time points and positions forming large temporal or spatial
databases. Particularly the analysis of concurrent and multidimensional sequences poses new challenges in finding clusters
of arbitrary length and varying number of attributes. We present a novel algorithm capable of finding parallel clusters in
different subspaces and demonstrate our results for temporal and spatial applications. Our analysis of structural quality
parameters in rivers is successfully used by hydrologists to develop measures for river quality improvements.
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19.
Mobile ad hoc networks without centralized infrastructure change their topology rapidly because of node mobility, making multimedia
applications difficult to run across wireless networks. Moreover, video transmission over ad hoc networks causes frequent
transmission loss of video packets owing to end-to-end transmission with a number of wireless links, and requires essential
bandwidth and restricted delay to provide quality-guaranteed display. This paper presents an architecture supporting transmission
of multiple video streams in ad hoc networks by establishing multiple routing paths to provide extra video coding and transport
schemes. This study also proposes an on-demand multicast routing protocol to transport layered video streams. The multicast
routing protocol transmits layered video streaming based on a weight criterion, which is derived according to the number of
receivers, delay and expiration time of a route. A simulation is performed herein to indicate the viability and performance
of the proposed approach. The simulation results demonstrate that the proposed transport scheme is more effective than other
video transport schemes with single or multiple paths.
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20.
The area of agent systems design may be safely described as cluttered and disorganized, especially by those that situate themselves
outside the “agent community”. Despite the wealth of bibliography on agent systems design and applications, there are few
widely acknowledged design methods that have surfaced from testing and practice, mainly in laboratory settings. The paper
contributes to the understanding of the field by presenting a critical review of methodologies that have emerged over the
last few years to guide and explain agent systems design and development. The perspective for this review has been mainly
formulated by posing important research questions in the field, and by attempting to interpret and discover latent hypotheses
and underlying assumptions made by methodologies in reference to relevant research, both in agent systems and cooperative
information systems practice and theory. The paper identifies significant challenges for agent systems methodologies that,
if pursued, can contribute to a new understanding of the field that shifts the foci of current agent systems research, towards
holistic design methods that place human users and information systems stakeholders at the centre of interest and involve
them in the design process as much as possible.
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