220 research outputs found

    Power management for interactive 3D games

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    Ph.DDOCTOR OF PHILOSOPH

    On a New, Efficient Framework for Falsifiable Non-interactive Zero-Knowledge Arguments

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    Et kunnskapsløst bevis er en protokoll mellom en bevisfører og en attestant. Bevisføreren har som mål å overbevise attestanten om at visse utsagn er korrekte, som besittelse av kortnummeret til et gyldig kredittkort, uten å avsløre noen private opplysninger, som for eksempel kortnummeret selv. I mange anvendelser er det ønskelig å bruke IIK-bevis (Ikke-interaktive kunnskapsløse bevis), der bevisføreren produserer kun en enkelt melding som kan bekreftes av mange attestanter. En ulempe er at sikre IIK-bevis for ikke-trivielle språk kun kan eksistere ved tilstedeværelsen av en pålitelig tredjepart som beregner en felles referansestreng som blir gjort tilgjengelig for både bevisføreren og attestanten. Når ingen slik part eksisterer liter man av og til på ikke-interaktiv vitne-uskillbarhet, en svakere form for personvern. Studiet av effektive og sikre IIK-bevis er en kritisk del av kryptografi som har blomstret opp i det siste grunnet anvendelser i blokkjeder. I den første artikkelen konstruerer vi et nytt IIK-bevis for språkene som består av alle felles nullpunkter for en endelig mengde polynomer over en endelig kropp. Vi demonstrerer nytteverdien av beviset ved flerfoldige eksempler på anvendelser. Særlig verdt å merke seg er at det er mulig å gå nesten automatisk fra en beskrivelse av et språk på et høyt nivå til definisjonen av IIK-beviset, som minsker behovet for dedikert kryptografisk ekspertise. I den andre artikkelen konstruerer vi et IIV-bevis ved å bruke en ny kompilator. Vi utforsker begrepet Kunnskapslydighet (et sterkere sikkerhetsbegrep enn lydighet) for noen konstruksjoner av IIK-bevis. I den tredje artikkelen utvider vi arbeidet fra den første artikkelen ved å konstruere et nytt IIK-bevis for mengde-medlemskap som lar oss bevise at et element ligger, eller ikke ligger, i den gitte mengden. Flere nye konstruksjoner har bedre effektivitet sammenlignet med allerede kjente konstruksjoner.A zero-knowledge proof is a protocol between a prover, and a verifier. The prover aims to convince the verifier of the truth of some statement, such as possessing credentials for a valid credit card, without revealing any private information, such as the credentials themselves. In many applications, it is desirable to use NIZKs (Non-Interactive Zero Knowledge) proofs, where the prover sends outputs only a single message that can be verified by many verifiers. As a drawback, secure NIZKs for non-trivial languages can only exist in the presence of a trusted third party that computes a common reference string and makes it available to both the prover and verifier. When no such party exists, one sometimes relies on non interactive witness indistinguishability (NIWI), a weaker notion of privacy. The study of efficient and secure NIZKs is a crucial part of cryptography that has been thriving recently due to blockchain applications. In the first paper, we construct a new NIZK for the language of common zeros of a finite set of polynomials over a finite field. We demonstrate its usefulness by giving a large number of example applications. Notably, it is possible to go from a high-level language description to the definition of the NIZK almost automatically, lessening the need for dedicated cryptographic expertise. In the second paper, we construct a NIWI using a new compiler. We explore the notion of Knowledge Soundness (a security notion stronger than soundness) of some NIZK constructions. In the third paper, we extended the first paper’s work by constructing a new set (non-)membership NIZK that allows us to prove that an element belongs or does not belong to the given set. Many new constructions have better efficiency compared to already-known constructions.Doktorgradsavhandlin

    Dronevision: An Experimental 3D Testbed for Flying Light Specks

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    Today's robotic laboratories for drones are housed in a large room. At times, they are the size of a warehouse. These spaces are typically equipped with permanent devices to localize the drones, e.g., Vicon Infrared cameras. Significant time is invested to fine-tune the localization apparatus to compute and control the position of the drones. One may use these laboratories to develop a 3D multimedia system with miniature sized drones configured with light sources. As an alternative, this brave new idea paper envisions shrinking these room-sized laboratories to the size of a cube or cuboid that sits on a desk and costs less than 10K dollars. The resulting Dronevision (DV) will be the size of a 1990s Television. In addition to light sources, its Flying Light Specks (FLSs) will be network-enabled drones with storage and processing capability to implement decentralized algorithms. The DV will include a localization technique to expedite development of 3D displays. It will act as a haptic interface for a user to interact with and manipulate the 3D virtual illuminations. It will empower an experimenter to design, implement, test, debug, and maintain software and hardware that realize novel algorithms in the comfort of their office without having to reserve a laboratory. In addition to enhancing productivity, it will improve safety of the experimenter by minimizing the likelihood of accidents. This paper introduces the concept of a DV, the research agenda one may pursue using this device, and our plans to realize one

    ARIVU: Power-Aware Middleware for Multiplayer Mobile Games

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    Ministry of Education, Singapore under its Academic Research Funding Tier

    Autonomous Unmanned Aerial Vehicle Navigation using Reinforcement Learning: A Systematic Review

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    There is an increasing demand for using Unmanned Aerial Vehicle (UAV), known as drones, in different applications such as packages delivery, traffic monitoring, search and rescue operations, and military combat engagements. In all of these applications, the UAV is used to navigate the environment autonomously --- without human interaction, perform specific tasks and avoid obstacles. Autonomous UAV navigation is commonly accomplished using Reinforcement Learning (RL), where agents act as experts in a domain to navigate the environment while avoiding obstacles. Understanding the navigation environment and algorithmic limitations plays an essential role in choosing the appropriate RL algorithm to solve the navigation problem effectively. Consequently, this study first identifies the main UAV navigation tasks and discusses navigation frameworks and simulation software. Next, RL algorithms are classified and discussed based on the environment, algorithm characteristics, abilities, and applications in different UAV navigation problems, which will help the practitioners and researchers select the appropriate RL algorithms for their UAV navigation use cases. Moreover, identified gaps and opportunities will drive UAV navigation research

    Vice : an interface designed for complex engineering software : an application of virtual reality

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    Concurrent Engineering has been taking place within the manufacturing industry for many years whereas the construction industry has until recently continued using the 'over the wall' approach where each task is completed before the next began. For real concurrent engineering in construction to take place there needs to be true collaborative working between client representatives, construction professionals, suppliers and subcontractors. The aim of this study was to design, develop and test a new style of user interface which promotes a more intuitive form of interaction than the standard desktop metaphor based interface. This new interface has been designed as an alternative for the default interface of the INTEGRA system and must also promote enhanced user collaboration. By choosing alternative metaphors that are more obvious to the user it is postulated that it should be possible for such an interface to be developed. Specific objectives were set that would allow the project aim to be fulfilled. These objectives are outlined below: To gain a better understanding of the requirements of successful concurrent engineering particularly at the conceptual design phase. To complete a thorough review of the current interfaces had to take place including any guidelines on how to create a "good user interface". To experience many of the collaboration systems available today so that an informed choice of application can be made. To learn the relevant skills required to design, produce and implement the interface of choice. To perform a user evaluation of the finished user interface to improve overall usability and further streamline the concurrent conceptual design. The user interface developed used a virtual reality environment to create a metaphor of an office building. Project members could then coexist and interact within the building promoting collaboration and at the same time have access to the remaining INTEGRA tools. The user evaluation proved that the Virtual Integrated Collaborative Environment (VICE) user interface was a successful addition to the INTEGRA system. The system was evaluated by a substantial number of different users which validates this finding. The user evaluation also provided positive results from two different demographics concluding that the system was easy, intuitive to use with the necessary functionality. Using metaphor based user interfaces is not a new concept. It has become standard practise for most software developers. There are arguments for and against these types of user interfaces. Some advanced users will argue that having such an interface limits their ability to make full use of the applications. However the majority of users do not come within this bracket and for them, metaphor based user interfaces are very useful. This is again evident from the user evaluation.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    CHORUS Deliverable 2.1: State of the Art on Multimedia Search Engines

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    Based on the information provided by European projects and national initiatives related to multimedia search as well as domains experts that participated in the CHORUS Think-thanks and workshops, this document reports on the state of the art related to multimedia content search from, a technical, and socio-economic perspective. The technical perspective includes an up to date view on content based indexing and retrieval technologies, multimedia search in the context of mobile devices and peer-to-peer networks, and an overview of current evaluation and benchmark inititiatives to measure the performance of multimedia search engines. From a socio-economic perspective we inventorize the impact and legal consequences of these technical advances and point out future directions of research

    Cubic-panorama image dataset analysis for storage and transmission

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    Meaningful lines : Social semiotic investigations of the graphical line, used as a connector in digital data visualizations

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    The paper III is not published yet.The dissertation investigates the graphical line, used as a connector in digital data visualizations (DVs), from a social semiotic perspective. It explores the semiotic functions of connecting lines in digital DVs, building empirically on two corpus analyses. These analyses are concerned with how two key semiotic functions are graphically realized in the selected lines and whether graphical conventions regulating these realizations can be identified. In the dissertation the connecting line is researched as a central element of several different DV types – line graphs, timelines, route maps, connection maps, network diagrams, etc. Today, DVs are used in a broad range of social contexts and thus play an essential role in society. New digital technologies make it possible to apply other visual characteristics to graphical lines in DVs than was previously possible, for example, when they were hand-drawn or printed. This change may have influenced the DV design practice, a situation calling for updated research. The dissertation is article-based, comprising three articles and an extended abstract. The extended abstract frames the three articles and includes an introduction, definitions of key terms, more comprehensive sections on the theoretical framework, earlier research and methodology, as well as ethical considerations, reflections on methodological decisions and a conclusion. The two overall research questions addressed in the dissertation are: (1) What characterizes the graphical forms and semiotic functions of connecting lines in current, publicly available digital DVs? (2) What conventions, regulating the relations between these forms and functions, can be observed in such DVs?publishedVersio

    Emotions, behaviour and belief regulation in an intelligent guide with attitude

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    Abstract unavailable please refer to PD
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