705 research outputs found

    An expressive hybrid model for the composition of cardinal directions

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    In our previous paper (Kor and Bennett, 2003), we have shown how the nine tiles in the projection-based model for cardinal directions can be partitioned into sets based on horizontal and vertical constraints (called Horizontal and Vertical Constraints Model). In order to come up with an expressive hybrid model for direction relations between two-dimensional single-piece regions (without holes), we integrate the well-known RCC-8 model with the above-mentioned model. From this expressive hybrid model, we derive 8 atomic binary relations and 13 feasible as well as jointly exhaustive relations for the x and y directions respectively. Based on these atomic binary relations, we derive two separate 8x8 composition tables for both the expressive and weak direction relations. We introduce a formula that can be used for the computation of the composition of expressive and weak direction relations between ‘whole or part’ regions. Lastly, we also show how the expressive hybrid model can be used to make several existential inferences that are not possible for existing models

    A Hybrid Reasoning Model for “Whole and Part” Cardinal Direction Relations

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    We have shown how the nine tiles in the projection-based model for cardinal directions can be partitioned into sets based on horizontal and vertical constraints (called Horizontal and Vertical Constraints Model) in our previous papers (Kor and Bennett, 2003 and 2010). In order to come up with an expressive hybrid model for direction relations between two-dimensional single-piece regions (without holes), we integrate the well-known RCC-8 model with the above-mentioned model. From this expressive hybrid model, we derive 8 basic binary relations and 13 feasible as well as jointly exhaustive relations for the x- and y-directions, respectively. Based on these basic binary relations, we derive two separate composition tables for both the expressive and weak direction relations. We introduce a formula that can be used for the computation of the composition of expressive and weak direction relations between “whole or part” regions. Lastly, we also show how the expressive hybrid model can be used to make several existential inferences that are not possible for existing models

    Pictorial Socratic dialogue and conceptual change

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    Counter-examples used in a Socratic dialogue aim to provoke reflection to effect conceptual changes. However, natural language forms of Socratic dialogues have their limitations. To address this problem, we propose an alternative form of Socratic dialogue called the pictorial Socratic dialogue. A Spring Balance System has been designed to provide a platform for the investigation of the effects of this pedagogy on conceptual changes. This system allows learners to run and observe an experiment. Qualitative Cartesian graphs are employed for learners to represent their solutions. Indirect and intelligent feedback is prescribed through two approaches in the pictorial Socratic dialogue which aim to provoke learners probe through the perceptual structural features of the problem and solution, into the deeper level of the simulation where Archimedes’ Principle governs

    A Belief Rule-Based Environmental Responsibility Assessment for Small and Medium-Sized Enterprises

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    This paper is an extension of [17]. This research proposes the use of a Belief Rule-Based approach to assess an enterprise’s level commitment to environmental issues. Participating companies will have to complete a structured questionnaire. An automated analysis of their responses will determine their environmental responsibility level. This is followed by a recommendation on how to progress to the next level. The recommended best practices will help promote understanding, increase awareness, and make the organization greener. BRB Expert systems consist of two parts: Knowledge Base and Inference Engine, which are used to derive valid conclusions from rules, established by experts with domain-specific knowledge. The knowledge base in this research is constructed after an in-depth literature review, critical analyses of existing environmental performance assessment models and primarily guided by the EU Draft Background Report for the development of an EMAS Sectoral Reference Document on "Best Environmental Management Practice in the Telecommunications and ICT Services Sector". The reasoning algorithm of a selected Drools JBoss BRB inference engine is forward chaining. However, the forward chaining mechanism is not equipped with uncertainty handling. Therefore, a decision is made to deploy an evidential reasoning and forward chaining with a hybrid knowledge representation inference scheme to accommodate imprecision, ambiguity and fuzzy types of uncertainties. It is believed that such a system generates well balanced, sensible and Green ICT readiness adapted results, to help enterprises focus on making improvements on more sustainable business operations

    Building Realistic Mobility Models for Mobile Ad Hoc Networks

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    A mobile ad hoc network (MANET) is a self-configuring wireless network in which each node could act as a router, as well as a data source or sink. Its application areas include battlefields and vehicular and disaster areas. Many techniques applied to infrastructure-based networks are less effective in MANETs, with routing being a particular challenge. This paper presents a rigorous study into simulation techniques for evaluating routing solutions for MANETs with the aim of producing more realistic simulation models and thereby, more accurate protocol evaluations. MANET simulations require models that reflect the world in which the MANET is to operate. Much of the published research uses movement models, such as the random waypoint (RWP) model, with arbitrary world sizes and node counts. This paper presents a technique for developing more realistic simulation models to test and evaluate MANET protocols. The technique is animation, which is applied to a realistic scenario to produce a model that accurately reflects the size and shape of the world, node count, movement patterns, and time period over which the MANET may operate. The animation technique has been used to develop a battlefield model based on established military tactics. Trace data has been used to build a model of maritime movements in the Irish Sea. Similar world models have been built using the random waypoint movement model for comparison. All models have been built using the ns-2 simulator. These models have been used to compare the performance of three routing protocols: dynamic source routing (DSR), destination-sequenced distance-vector routing (DSDV), and ad hoc n-demand distance vector routing (AODV). The findings reveal that protocol performance is dependent on the model used. In particular, it is shown that RWP models do not reflect the performance of these protocols under realistic circumstances, and protocol selection is subject to the scenario to which it is applied. To conclude, it is possible to develop a range of techniques for modelling scenarios applicable to MANETs, and these simulation models could be utilised for the evaluation of routing protocols

    Mixed-Resolution HEVC based multiview video codec for low bitrate transmission

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    Sustainable and Green Information Systems: Preparing the next generation of practitioners.

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    Sustainable development and green computing issues are increasingly important for computing professionals. Preparing the next generation of implementers and developers requires that Higher Education providers develop curriculum to reflect this. There are a number of drivers behind this – encompassing industry and professional body demands, policy makers’ directives, as well as institutional commitments to sustainability. Other reasons include the effectiveness of this topic as a way to address particular issues in engagement and recruitment to computing courses. When considering “sustainability" or ("green-ness") in teaching, we should consider the appropriateness and suitability of material, and target it at an appropriate level. There are also choices about how to present the material so as to match students’ motivation, which can reflect gender and other demographic issues. Institutions can adopt different approaches, such as specialised courses as components of wider programmes, or as specialised courses in their own right. Some approaches integrate the topic into undergraduate teaching, treating environmental impact as a design constraint within a solution. This paper reports on some of these variations and directs readers to an online resource to enable colleagues interested in this topic to share ideas and approaches. Whilst the focus is on computing, many of the issues are transferrable to other STEM disciplines

    MIXED-RESOLUTION HEVC BASED MULTIVIEW VIDEO CODEC

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    Studies have shown that mixed resolution based video codecs, also known as asymmetric spatial inter/intra view video codecs are successful in efficiently coding videos for low bitrate trans-mission. In this paper a HEVC based spatial resolution scaling type of mixed resolution coding model for frame interleaved multiview videos is presented. The proposed codec is designed such that the information in intermediate frames of the center and neighboring views are down-sampled, while the frames still retaining the original size. The codec’s reference frames structure is designed to efficiently encode frame interleaved multi-view videos using a HEVC based mixed resolution codec. The multi-view test video sequences were coded using the proposed codec and the standard MV-HEVC. Results show that the pro-posed codec gives significantly higher coding performance over the MV- HEVC codec at low bitrates

    HEVC based Mixed-resolution Stereo Video Coding for Low Bitrate Transmission

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    This paper presents a mixed resolution stereo video coding model for High Efficiency Video Codec (HEVC). The challenging aspects of mixed resolution video coding are enabling the codec to encode frames with different frame resolution/size and using decoded pictures having different frame resolution/size for referencing. These challenges are further enlarged when implemented using HEVC, since the incoming video frames are subdivided into coding tree units. The ingenuity of the proposed codec’s design, is that the information in intermediate frames are down-sampled and yet the frames can retain the original resolution. To enable random access to full resolution decoded frame in the decoded picture buffer as reference frame a downsampled version of the decoded full resolution frame is used. The test video sequences were coded using the proposed codec and standard MV-HEVC. Results show that the proposed codec gives a significantly higher coding performance over the MV- HEVC codec
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