Browsing by Subject "Interactive computer systems"

Now showing 1 - 9 of 9

Open Access
Distributed interactive video system design and analysis
(Institute of Electrical and Electronics Engineers, 1997) Wu, Tsong-Ho; Korpeoglu, I.; Cheng, Bo-Chao
The interactive video (IV) market has been expected to capture a significant share of the huge potential revenues to be generated by the business and residential markets. The level of revenues generated depends on the completion rate of calls the service provider can support, no matter what the IV system or network condition. Thus, a cost-effective, scalable fault-tolerant IV system is needed to maximize the video call completion rate at an affordable cost. This article describes design methodologies for a scalable, fault-tolerant IV system and an IV system design and analysis research prototype called IVSDNA (IV System Designer and Analyzer). The IVSDNA prototype is designed to help network planners and engineers to evaluate quantitative trade-offs (in terms of network communications costs, video storage costs, and degree of system fault tolerance) between two major IV system architectures (centralized and distributed) with a variety of video distribution methods, replication strategies, and fault-tolerant access protocols.
Open Access
How to teach usage of equipments in a remote laboratory
(IEEE, 2007-09) Alparslan, N. Ceren; Özen, M.; Cağiltay, N. E.; Aydın, E.
European Remote Radio Laboratory (ERRL) is an e-learning project for students, teachers and technicians of the universities who will use the very important devices of this laboratory remotely. These devices are very expensive to buy and can be broken easily while they have been using by the people who does not really know how to use them professionally. As a solution we have developed an e-learning system which aims to support the ERRL learners while studying on how to use equipments in the system. The system is developed according to the electronic performance support systems (EPSS) approach. An EPSS is a computer-based, well-structured system which improves the performance of individuals. It is an electronic infrastructure that contains, stores and distributes personal (individual) or corporate knowledge to enable people to reach necessary levels of performance in the fastest possible time and with minimum teaching support of other people. This paper discusses how the content for such a system is developed and how this content is interactively used in the EPSS platform. The technical details of the developed EPSS are also discussed in this study. We believe that this paper will help instructional system designers for designing different alternatives to improve learners' performance. © 2007 IEEE.
Open Access
Image sequence analysis for emerging interactive multimedia services-the European COST 211 framework
(Institute of Electrical and Electronics Engineers, 1998-11) Alatan, A. A.; Onural, L.; Wollborn, M.; Mech, R.; Tuncel, E.; Sikora, T.
Flexibility and efficiency of coding, content extraction, and content-based search are key research topics in the field of interactive multimedia. Ongoing ISO MPEG-4 and MPEG-7 activities are targeting standardization to facilitate such services. European COST Telecommunications activities provide a framework for research collaboration. COST 211 bis and COST 211 tcr activities have been instrumental in the definition and development of the ITU-T H.261 and H.263 standards for video-conferencing over ISDN and videophony over regular phone lines, respectively. The group has also contributed significantly to the ISO MPEG-4 activities. At present a significant effort of the COST 211 tcr group activities is dedicated toward image and video sequence analysis and segmentation - an important technological aspect for the success of emerging object-based MPEG-4 and MPEG-7 multimedia applications. The current work of COST 211 is centered around the test model, called the Analysis Model (AM). The essential feature of the AM is its ability to fuse information from different sources to achieve a high-quality object segmentation. The current information sources are the intermediate results from frame-based (still) color segmentation, motion vector based segmentation, and change-detection-based segmentation. Motion vectors, which form the basis for the motion vector based intermediate segmentation, are estimated from consecutive frames. A recursive shortest spanning tree (RSST) algorithm is used to obtain intermediate color and motion vector based segmentation results. A rule-based region processor fuses the intermediate results; a postprocessor further refines the final segmentation output. The results of the current AM are satisfactory; it is expected that there will be further improvements of the AM within the COST 211 project.
Open Access
An interactive software package for the investigation of hydrodynamic-slider bearing-lubrication
(2003) Ozalp, A.A.; Ozel, S.A.
The temperature dependent character of viscosity complicates the numerical analysis of hydrodynamic slider bearings and the geometry of the flow cavity plays a significant role on the design and performance of the lubrication systems. In this paper, we represent a recent software tool, named as "HYDRO-LUB," capable of performing constant and variable viscosity runs in various pad styles with moving boundaries. Results of the demonstrating project are not only consistent with the available literature but also show the fast and reliable character of the package; which in return put forward the advantages of applying the program in the lubrication courses of mechanical engineering. © 2003 Wiley Periodicals, Inc.
Open Access
Interactive training of advanced classifiers for mining remote sensing image archives
(ACM, 2004) Aksoy, Selim; Koperski, K.; Tusk, C.; Marchisio G.
Advances in satellite technology and availability of down-loaded images constantly increase the sizes of remote sensing image archives. Automatic content extraction, classification and content-based retrieval have become highly desired goals for the development of intelligent remote sensing databases. The common approach for mining these databases uses rules created by analysts. However, incorporating GIS information and human expert knowledge with digital image processing improves remote sensing image analysis. We developed a system that uses decision tree classifiers for interactive learning of land cover models and mining of image archives. Decision trees provide a promising solution for this problem because they can operate on both numerical (continuous) and categorical (discrete) data sources, and they do not require any assumptions about neither the distributions nor the independence of attribute values. This is especially important for the fusion of measurements from different sources like spectral data, DEM data and other ancillary GIS data. Furthermore, using surrogate splits provides the capability of dealing with missing data during both training and classification, and enables handling instrument malfunctions or the cases where one or more measurements do not exist for some locations. Quantitative and qualitative performance evaluation showed that decision trees provide powerful tools for modeling both pixel and region contents of images and mining of remote sensing image archives.
Open Access
Query expansion with terms selected using lexical cohesion analysis of documents
(Elsevier Ltd, 2007-07) Vechtomova, O.; Karamuftuoglu, M.
We present new methods of query expansion using terms that form lexical cohesive links between the contexts of distinct query terms in documents (i.e., words surrounding the query terms in text). The link-forming terms (link-terms) and short snippets of text surrounding them are evaluated in both interactive and automatic query expansion (QE). We explore the effectiveness of snippets in providing context in interactive query expansion, compare query expansion from snippets vs. whole documents, and query expansion following snippet selection vs. full document relevance judgements. The evaluation, conducted on the HARD track data of TREC 2005, suggests that there are considerable advantages in using link-terms and their surrounding short text snippets in QE compared to terms selected from full-texts of documents. © 2006 Elsevier Ltd. All rights reserved.
Open Access
Snippet based trajectory statistics histograms for assistive technologies
(Springer, 2014-09) İscen, Ahmet; Wang Y.; Duygulu, Pınar; Hauptmann, A.
Due to increasing hospital costs and traveling time, more and more patients decide to use medical devices at home without traveling to the hospital. However, these devices are not always very straight-forward for usage, and the recent reports show that there are many injuries and even deaths caused by the wrong use of these devices. Since human supervision during every usage is impractical, there is a need for computer vision systems that would recognize actions and detect if the patient has done something wrong. In this paper, we propose to use Snippet Based Trajectory Statistics Histograms descriptor to recognize actions in two medical device usage problems; inhaler device usage and infusion pump usage. Snippet Based Trajectory Statistics Histograms encodes the motion and position statistics of densely extracted trajectories from a video. Our experiments show that by using Snippet Based Trajectory Statistics Histograms technique, we improve the overall performance for both tasks. Additionally, this method does not require heavy computation, and is suitable for real-time systems. © Springer International Publishing Switzerland 2015.
Open Access
Walkthrough in complex environments at interactive rates using level-of-detail
(TÜBİTAK, 2002) Selçuk, Alper; Güdükbay, Uğur; Özgüç, Bülent
One of the biggest problems in computer graphics is displaying huge geometric models at interactive rates. A lot of work has been done to achieve the required frame-rates in architecture, simulation, computer-aided design and entertainment applications. In this paper, a system that enables walkthrough in complex environments using level-of-detail approximations is explained. The system uses hierarchical triangulated models as input. In the preprocessing phase, multiresolution models of objects are created using polygonal simplification techniques. During walkthrough, fast frustum culling based on bounding boxes is performed to eliminate branches of hierarchy that are not visible. An appropriate level for detail of objects is selected and displayed depending on the distance of the objects to the camera. For far nodes in the hierarchy, geometric data in lower levels is ignored and textured bounding boxes are displayed. The system achieves interactive frame rates for moderately complex models containing up to a million polygons.
Open Access
Which shape representation is the best for real-time hand interface system?
(Springer, Berlin, Heidelberg, 2009) Genç, Serkan; Atalay V.
Hand is a very convenient interface for immersive human-computer interaction. Users can give commands to a computer by hand signs (hand postures, hand shapes) or hand movements (hand gestures). Such a hand interface system can be realized by using cameras as input devices, and software for analyzing the images. In this hand interface system, commands are recognized by analyzing the hand shapes and its trajectories in the images. Therefore, success of the recognition of hand shape is vital and depends on the discriminative power of the hand shape representation. There are many shape representation techniques in the literature. However, none of them are working properly for all shapes. While a representation leads to a good result for a set of shapes, it may fail in another one. Therefore, our aim is to find the most appropriate shape representation technique for hand shapes to be used in hand interfaces. Our candidate representations are Fourier Descriptors, Hu Moment Invariant, Shape Descriptors and Orientation Histogram. Based on widely-used hand shapes for an interface, we compared the representations in terms of their discriminative power and speed. © 2009 Springer-Verlag.