Spelling suggestions: "subject:"datat ocho informationsvetenskap"" "subject:"datat och3 informationsvetenskap""
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Social Navigation in a Location-Based Information SystemFagerberg, Petra January 2002 (has links)
Much of contextaware application research has dealt with the technical aspects of context capturing and how to interpret the context of a user. Little effort has been spent on the experience and usage of these systems. This thesis will present the general aspects of social awareness and present an example on how these concepts can be implemented into a location-based information system to help users navigate a potential information overload. This thesis also states that giving the users an experience of not being alone in the system increases the pleasure of using such a system. However this implies a decrease in privacy. To demonstrate these ideas I will describe a locationbased information system, GeoNotes, built by a group of researchers at SICS, the Swedish Institute of Computer Science. I will state a set of interaction requirements for how to extend the GeoNotes system with functionality for social awareness. Furthermore I will set up functional requirements for those interaction requirements to after implementation be able to conclude which interaction requirements I have been able to implement for. I will also give suggestions on how to position users in a WLAN. The deliverable from this project is a locationbased information system with functionality for social awareness. However, it was not within this project to test the system on true users. Therefore the statement that this functionality can help users to navigate a potential information overload is still just a hypothesis. To retrieve the position of a user in a W-LAN a packet is sent to all base stations in the network. In the first returning packet the mac address of contacting base station is extracted. Each base station is therefore a unique position. Triangulation was discarded due to its sensitivity to noise and weather circumstances, although a system that uses triangulation would have offered a much higher granularity.
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Tracing and Explaining the Execution of CLP(FD) Programs in SICStus PrologÅgren, Magnus January 2002 (has links)
The increasing interest in Constraint Programming (CP) we now witness gives rise to a demand for new and improved debugging techniques. Graphical tools, such as constraint- and search-tree visualizers, seem to be appropriate to get a general understanding of the complex process of constraint solving. However, many such tools have been built in an ad hoc way, forcing the developer to, for each new tool, provide relevant information from the constraint solver. In this thesis, we present a solution to the problem, limiting ourselves to Constraint Logic Programming over Finite Domains (clpfd). In order to do this, we come up with a trace structure for describing the execution of clpfd programs in detail. The trace structure consists of various trace events, each trace event containing different information depending on when in the solving process it is created. Among other things, the trace structure contains information about constraint posting, constraint awakening and domain narrowing. We also incorporate explanations in the trace structure, i.e. reasons for why certain solver actions occur. Furthermore, we come up with a format for describing the execution of the filtering algorithms of global constraints. An implementation of the trace structure in sicstus Prolog is also presented, as well as a tool using the trace; an extension to the ordinary Prolog debugger.
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Security Services on an Optimized Thin Hypervisor for Embedded SystemsDo, Viktor January 2011 (has links)
Virtualization has been used in computer servers for a long time as a means to improve utilization, isolation and management. In recent years, embedded devices have become more powerful, increasingly connected and able to run applications on open source commodity operating systems. It only seems natural to apply these virtualization techniques on embedded systems, but with another objective. In computer servers, the main goal was to share the powerful computers with multiple guests to maximize utilization. In embedded systems the needs are different. Instead of utilization, virtualization can be used to support and increase security by providing isolation and multiple secure execution environments for its guests. This thesis presents the design and implementation of a security application, and demonstrates how a thin software virtualization layer developed by SICS can be used to increase the security for a single FreeRTOS guest on an ARM platform. In addition to this, the thin hypervisor was also analyzed for improvements in respect to footprint and overall performance. The selected improvements were then applied and verified with profiling tools and benchmark tests. Our results show that a thin hypervisor can be a very flexible and efficient software solution to provide a secure and isolated execution environment for security critical applications. The applied optimizations reduced the footprint of the hypervisor by over 52%, while keeping the performance overhead at a manageable level.
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Thin Hypervisor-Based Security Architectures for Embedded PlatformsDouglas, Heradon January 2010 (has links)
Virtualization has grown increasingly popular, thanks to its benefits of isolation, management, and utilization, supported by hardware advances. It is also receiving attention for its potential to support security, through hypervisor-based services and advanced protections supplied to guests. Today, virtualization is even making inroads in the embedded space, and embedded systems, with their security needs, have already started to benefit from virtualization’s security potential. In this thesis, we investigate the possibilities for thin hypervisor-based security on embedded platforms. In addition to significant background study, we present implementation of a low-footprint, thin hypervisor capable of providing security protections to a single FreeRTOS guest kernel on ARM. Backed by performance test results, our hypervisor provides security to a formerly unsecured kernel with minimal performance overhead, and represents a first step in a greater research effort into the security advantages and possibilities of embedded thin hypervisors. Our results show that thin hypervisors are both possible and beneficial even on limited embedded systems, and sets the stage for more advanced investigations, implementations, and security applications in the future. / SVAMP
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Designing for/from the FutureÖnal, Başar January 2010 (has links)
This thesis aims to introduce new methods within the field of experience design, an emergent interdisciplinary design discipline, using these methods as tools for debate and for the communication of new design concepts. An important part of the methods come from trendspotting practice and future studies methodology. The backbone of the final project is a “meta-method” which incorporates common methods surveyed so far: the “for/from” method. The first part of the “for/from” method is about designing prototypes and creating fictional narratives to project current trends into the future, the second part is perhaps less structured, but more ambitious, carrying fictional futures to the daily lives, to test and evaluate the scenarios created. Staging experiments and experiences around these proposed methodologies and testing the concepts through workshops forms the core of the proposed design practice. Since the domain of futures thinking is not populated by designers, it is of special importance to me as how designers might find a place in such interdisciplinary teams and how the organizational levels of these so-called complex experiential structures could allow designers to participate. I argue that experience designers not only design customer experiences to please and aestheticize products but they have the power to change people’s (rather than customers’) opinions, using the same tools the field of marketing and exhibition design offers them. / SWITCH!
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Implementation and Evaluation of NetInf TP, an Information-centric Transport ProtocolAli, Noman Mumtaz, Potys, Robert January 2013 (has links)
In recent times, there has been a significant growth in the number of Internet users, resulting in an increased demand for different types and amounts of content. As content distribution over the Internet has become a key issue, one proposal is that the Internet architecture could evolve to a more ``Information-Centric'' paradigm instead of the currently designed ``Host-Centric'' paradigm. In the host-based architecture, the data is often restricted to a location and will become unavailable if the host holding the data (or network connection) becomes unreachable. With the Information-centric data approach, the requestor requests data and receives it regardless of where the data actually originated from. Hence, the focus moves from ``where'' to ``what'' one is interested in. The heterogeneity of access methods and devices makes this type of approach even more appealing, especially when caching of data at intermediate points can be achieved. The prototype developed in the thesis builds an important part of the Information-Centric vision, that is a receiver-driven transport protocol. This is in contrast to the host-centric transport protocols which are always source driven. The advantage of having the receiver driven feature is to allow for multiple senders or receivers of the same data. That is, one receiver may ask more than one holder to send different pieces of the same file. We have implemented, simulated and assessed the performance of the proposed protocol, hereby called NetInf TP. Since the protocol may have to co-exist with existing sender driven TCP implementations for some time, we have looked at the inter-operation of NetInf TP with TCP variants from both qualitative and quantitative perspectives. / CNS
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Reducing Food Waste in the Household through Behaviour Change.Spengemann, Pauline January 2011 (has links)
Sustainable ways of living
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Access Control in the Internet of ThingsDenis, Sitenkov January 2014 (has links)
The new generation of Wireless Sensor Networks, that is known as the Internet of Things enables the direct connection of physical objects to the Internet using microcontrollers. In most cases these microcontrollers have very limited computational resources. The global connectivity provides great opportunities for data collection and analysis as well as for interaction of objects that cannot be connected to the same local area network. Many of application scenarios have high requirements to security and privacy of transmitted data. At the same time security solutions that are utilized for general purpose computers are not always applicable for constrained devices. That leaves a room for new solutions that takes into account the technological aspects of the Internet of Things. In this thesis we investigate the access control solution for the IETF standard draft Constrained Application Protocol, using the Datagram Transport Layer Security protocol for transport security. We use the centralized approach to save access control information in the framework. Since the public key cryptography operations might be computationally too expensive for constrained devices we build our solution based on symmetric cryptography. Evaluation results show that the access control framework increases computational effort of the handshake by 6.0%, increases the code footprint of the Datagram Transport Layer Security implementation by 7.9% and has no effect on the overall handshake time. Our novel protocol is not vulnerable to Denial of Service or Drain Battery Attack. / Thesis supervised by Shahid Raza (shahid@sics.se) and Ludwig Seitz (ludwig@sics.se)
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Solving complex maintenance planning optimization problems using stochastic simulation and multi-criteria fuzzy decision makingTahvili, Sahar January 2014 (has links)
No description available.
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Exploring NAT Host Counting Using Network Traffic FlowsSalomonsson, Sebastian January 2017 (has links)
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