972 research outputs found
Requirement analysis and sensor specifications – First version
Full text linkIn this first version of the deliverable, we make the following contributions: to design the
WEKIT capturing platform and the associated experience capturing API, we use a
methodology for system engineering that is relevant for different domains such as: aviation,
space, and medical and different professions such as: technicians, astronauts, and medical
staff. Furthermore, in the methodology, we explore the system engineering process and how
it can be used in the project to support the different work packages and more importantly
the different deliverables that will follow the current.
Next, we provide a mapping of high level functions or tasks (associated with experience
transfer from expert to trainee) to low level functions such as: gaze, voice, video, body
posture, hand gestures, bio-signals, fatigue levels, and location of the user in the
environment. In addition, we link the low level functions to their associated sensors.
Moreover, we provide a brief overview of the state-of-the-art sensors in terms of their
technical specifications, possible limitations, standards, and platforms.
We outline a set of recommendations pertaining to the sensors that are most relevant for
the WEKIT project taking into consideration the environmental, technical and human
factors described in other deliverables. We recommend Microsoft Hololens (for Augmented
reality glasses), MyndBand and Neurosky chipset (for EEG), Microsoft Kinect and Lumo Lift
(for body posture tracking), and Leapmotion, Intel RealSense and Myo armband (for hand
gesture tracking). For eye tracking, an existing eye-tracking system can be customised to
complement the augmented reality glasses, and built-in microphone of the augmented
reality glasses can capture the expert’s voice. We propose a modular approach for the design
of the WEKIT experience capturing system, and recommend that the capturing system
should have sufficient storage or transmission capabilities.
Finally, we highlight common issues associated with the use of different sensors. We
consider that the set of recommendations can be useful for the design and integration of the
WEKIT capturing platform and the WEKIT experience capturing API to expedite the time
required to select the combination of sensors which will be used in the first prototype.WEKI
Insights from a pseudospectral study of a potentially singular solution of the three-dimensional axisymmetric incompressible Euler equation
Full text linkWe develop a Fourier-Chebyshev pseudospectral direct numerical simulation
(DNS) to examine a potentially singular solution of the radially bounded,
three-dimensional (3D), axisymmetric Euler equations [G. Luo and T.Y. Hou,
Proc. Natl. Acad. Sci. USA, 111.36 (2014)]. We demonstrate that: (a) the time
of singularity is preceded, in any spectrally truncated DNS, by the formation
of oscillatory structures called tygers, first investigated in the
one-dimensional (1D) Burgers and two-dimensional (2D) Euler equations; (b) the
analyticity-strip method can be generalized to obtain an estimate for the
(potential) singularity time.Comment: 17 pages. 13 figure
Preparation and Characterization of microwave sintered SrFe12O19/NiFe2O4 nanocomposite
No full textIn the present work, microwave sintered nanocomposite of NiFe2O4 (NiF) and SrFe12O19 (SrM) in different weight fraction (80/20, 70/30, 60/40, 50/50) were prepared. Their phase, microstructure and magnetic properties were analyzed by X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Vibrating Sample Magnetometer (VSM) respectively. X-ray diffraction pattern confirmed co-existence of both spinel (NiFe2O4) and hexagonal (SrFe12O19) phases in sintered composites without any secondary phase. Kinked demagnetization curve was observed for powders as well as sintered composites. However kink was more prominent in powder samples. Obtained kink in M-H loops indicating non-exchange coupling between hard/soft phases. Contrary to powders, microwave sintered composites showed higher Ms values from theoretical calculated one confirmed that sintering adequately enhance the coupling between hard/soft phases
Towards three-dimensional visual saliency
Full text linkA salient image region is defined as an image part that is clearly different from its surround in terms of a number of attributes. In bottom-up processing, these attributes are defined as: contrast, color difference, brightness, and orientation. By measuring these attributes, visual saliency algorithms aim to predict the regions in an image that would attract our attention under free viewing conditions, i.e., when the observer is viewing an image without a specific task such as searching for an object. To quantify the interesting locations in a scene, the output of the visual saliency algorithms is usually expressed as a two dimensional gray scale map where the brighter regions correspond to the highly salient regions in the original image. In addition to advancing our understanding of human visual system, visual saliency models can be used for a number of computer vision applications. These applications include: image compression, computer graphics, image matching & recognition, design, and human-computer interaction.
In this thesis the main contributions can be outlined as: first, we present a method to inspect the performance of Itti’s classic saliency algorithm in separating the salient and non-salient image locations. Based on our results we observed that, although the saliency model can provide a good discrimination for the highly salient and non-salient regions, there is a large overlap between the locations that lie in the middle range of saliency. Second, we propose a new bottom-up visual saliency model for static two-dimensional images. In our model, we calculate saliency by using the transformations associated with the dihedral group D4. Our results suggest that the proposed saliency model outperforms many state-of-the-art saliency models. By using the proposed methodology, our algorithm can be extended to calculate saliency in three-dimensional scenes, which we intend to implement in the future. Third, we propose a way to perform statistical analysis of the fixations data from different observers and different images. Based on the analysis, we present a robust metric for judging the performance of the visual saliency algorithms. Our results show that the proposed metric can indeed be used to alleviate the problems pertaining to the evaluation of saliency models. Four, we introduce a new approach to compress an image based on the salient locations predicted by the saliency models. Our results show that the compressed images do not exhibit visual artifacts and appear to be very similar to the originals. Five, we outline a method to estimate depth from eye fixations in three-dimensional virtual scenes that can be used for creating so-called gaze maps for three-dimensional scenes. In the future, this can be used as ground truth for judging the performance of saliency algorithms for three-dimensional images.
We believe that our contributions can lead to a better understanding of saliency, address the major issues associated with the evaluation of saliency models, highlight on the contribution of top-down and bottom-up processing based on the analysis of a comprehensive eye tracking dataset, promote use of human vision steered image processing applications, and pave the way for calculating saliency in three-dimensional scenes.PhD i informasjonsteknologiPhD in Information Technolog
Effect of grain size and Gd-Co substitutions on multiferroic BiFeO3 thin films
No full textMultiferroics has attracted attention of researchers worldwide due to its fundamental and technological applications. Amongst multiferroics BiFeO3 (BFO) is the only known material to possess ferroelectric Curie temperature (TC=1143K) and antiferromagnetic Ne`el temperature (TN=643 K) well above room temperature. BFO crystallizes in a rhombohedrally distorted perovskite structure with R3c space group at room temperature. This is analogous to the hexagonal setting that contains six formula units of BFO in it with lattice constants ah = 5.587 Å, ch = 13.867 Å. The antiferromagnetic ordering of BFO is G-type having a spiral spin modulation with an incommensurate long-wavelength period of ~ 62 nm. Due to its antiferromagnetic nature; bulk BFO shows ineffectual magnetism that limits its device applications. On the other hand low resistivity of BFO leads to large leakage current limiting its ferroelectric applications. To overcome these limitations, attention has been diverted towards synthesis of thin films. Till date various techniques have been used to prepare and optimize conditions for preparation of BFO thin films. Considering the great potential of large magneto-electric effect in thin films, efforts have been made by researchers in the production of quality thin films of BFO. The magnetization and ferroelectric behaviour in BFO can be tailored by altering the grain size by adopting different methodology which includes varying annealing temperature and the film thickness. Besides, low level substitution of rare earth metal ions at Bi3+ site or transition metal ions at Fe3+ site also affects the magnetic and electrical properties. However, the recent approaches in the preparation of high quality polycrystalline thin films restrict the formation of grains with uniform size. It is therefore necessary to investigate the effect of grain size distribution to further reveal the intricate magnetic and electrical behaviour of BFO thin films. The present work focuses on the grain size distribution dependent magnetic and electrical properties of sol-gel driven BFO thin films. Further, the effect of substitution of Gd ion at Bi site and Co ion at Fe site has been studied. Also, the effect of simultaneous substitution of Gd and-Co has been investigated
Distributed Quality of Service Multicast Routing with Multiple Metrics for Receiver initiated Joins
Full text linkThis paper describes a novel method of building multicast trees for real time traffic with quality of service constraints. There is a wide range of heuristics to calculate the optimal multicast distribution trees with bounds on the maximum delay from the source to all members. However these heuristics require all the members to be known in advance and assume the existence of a centralized service. We present a heuristic-best cost individual join (BCIJ)-that joins members one by one, randomly to the existing tree. The method does not need previous knowledge of the group members. Trees are dynamically built when each member arrives in the group. A distributed method-multiple metric broadcast (MMB)-for nodes to obtain the best valid path to the existing tree is also presented. MMB is inspired by reverse path forwarding and broadcasts queries to the network that reach existing on-tree members. These reply with the best valid paths to the joining member. The member then selects the best path. This avoids the use of any centralized service and the need for link-state information to be available in any node. The evaluation presented shows that the BCIJ produces trees with better cost than existing centralized heuristics and that MMB does not have a major effect on the network if the group participation is sufficiently large
Content name resolution service implementation for cache and forward network architecture
No full textCache aNd Forward (CNF) is a proposed architecture for content delivery services in the future Internet. The CNF architecture takes advantage of reductions in storage to design a network that directly addresses the mobile content delivery problem. The CNF architecture uses a content name resolution service protocol, along with a reliable hop-by-hop transport protocol, storage aware routing protocol in place of end-to-end TCP for reliable delivery of large files. This thesis presents the algorithms proposed for a distributed name resolution protocol and design and experimental evaluation of the protocol on ORBIT in context of a multi-hop wireless access network scenario. The protocol is designed using hashing technique such that when a host queries for a file, the name service will be triggered and will return the addresses of nodes that cache the file. Since our architecture is about caching and forwarding large content files, enabling hosts to retrieve files from the network and not necessarily from the origin server, we need to uniquely identify the files. To that effect, we propose to identify a file using a unique content identifier (CID) where CID is obtained by a one way hashing (SHA1) on the content itself. The aim here is to optimize selection of cache location and serve the host with the file from the nearest location. If the selected cache location is determined to be temporarily degraded, either due to poor channel conditions or mobility, the protocol uses multiple hash technique to provide alternate cache locations and the decision is based on the ETT metric provided by the routing protocol. The CNRS protocol over multi-hop 802.11 access networks with CNF routers has been implemented as a real-time proof-of-concept prototype on the ORBIT testbed. Baseline results for CNRS with hop-by-hop transport show that content based CNF network architecture performs better than TCP/IP stack. Using different content distributions, we have shown that multiple hashing, popularity based and location based caching provide significant gains over the baseline algorithm.M.S.Includes bibliographical referencesby Puneet Katari
Flexible Denture: A Hope for Partial Edentulous Patient- A Case Report
Full text linkThe various treatment options for the aesthetic and functional rehabilitation of partially edentulous patients are conventional fixed partial dentures, implant supported fixed partial dentures and removable partial dentures. In some cases, removable partial dentures may be the only choice which is available other than implants and fixed partial denture. Removable cast partial dentures are used as definitive removable prostheses when indicated, but location of clasps is not aesthetically pleasant. So, when patient is concerned about aesthetics, flexible partial dentures which is aesthetically superior may be considered. But for the success of flexible removable partial denture, proper diagnosis, treatment planning, insertion, wearing and maintenance of this prosthesis is very important
- …
