224,068 research outputs found
COLLABORATIVE CAD MODELING PROCESS ANALYSIS TO SUPPORT TEAMWORK FOR BUILDING DESIGN
Collaborative tools are information systems which allow document sharing through local area networks, intranets and extranets. Collaborative design can be a solution to increase the productivity and the final quality of the product in a building design office. In this way it is possible to assure the information integration and also the data integrity during the design process based on computer network communication. The goal of this article is to analyze how one CAD system based on BIM concept (ArchiCAD software - Graphisoft/Nemetschek) can support a collaborative teamwork structured on an integrated model for different design views. In this model, the tasks are assigned by a coordinator and executed by the designers in different places following the client-service scheme. It is intended to contribute with the diffusion of this information technology tool and to present its potentiality for the improvement of the design performance. The research method used was a case study of the development design. In this case study, communication guidelines had been applied to verify the software behavior in relation to the task execution in a shared framework. The use of the collaborative CAD modeling in the development design provided information sharing, track and control of document versions and also the integration of design modifications in such automatic and simultaneous way between different computers used.Collaborative tools are information systems which allow document sharing through local area networks, intranets and extranets. Collaborative design can be a solution to increase the productivity and the final quality of the product in a building design office. In this way it is possible to assure the information integration and also the data integrity during the design process based on computer network communication. The goal of this article is to analyze how one CAD system based on BIM concept (ArchiCAD software - Graphisoft/Nemetschek) can support a collaborative teamwork structured on an integrated model for different design views. In this model, the tasks are assigned by a coordinator and executed by the designers in different places following the client-service scheme. It is intended to contribute with the diffusion of this information technology tool and to present its potentiality for the improvement of the design performance. The research method used was a case study of the development design. In this case study, communication guidelines had been applied to verify the software behavior in relation to the task execution in a shared framework. The use of the collaborative CAD modeling in the development design provided information sharing, track and control of document versions and also the integration of design modifications in such automatic and simultaneous way between different computers used
Decision Support for Healthcare ICT Network System Appraisal
A framework to support the appraisal process to improve the quality of service (QoS) of an Information and Communication Technology (ICT) network system in health care service is presented. Most of health-related activities stand to benefit from ICT endorsement; however, technical problems may appear, as an inadequate physical infrastructure, insufficient access by the user to the hardware/software communication infrastructure and QoS issues. The aim is to develop a prototype assessment model based on data collected from the main users of a health network system An evaluation process is carried out to analyze and assess the support of QoS of ICT, its infrastructure and user interface perception of the QoS offered through case study for hospitals in Chile. Performance has been evaluated by simulation and modelling network Architecture. The Optimization Network Engineering Tool (OPNET) simulation platform is used to examine the network behaviour and performance to ensure consistency and reliability for thousands of staff across the hospital network
A machine learning-based framework for preventing video freezes in HTTP adaptive streaming
HTTP Adaptive Streaming (HAS) represents the dominant technology to deliver videos over the Internet, due to its ability to adapt the video quality to the available bandwidth. Despite that, HAS clients can still suffer from freezes in the video playout, the main factor influencing users' Quality of Experience (QoE). To reduce video freezes, we propose a network-based framework, where a network controller prioritizes the delivery of particular video segments to prevent freezes at the clients. This framework is based on OpenFlow, a widely adopted protocol to implement the software-defined networking principle. The main element of the controller is a Machine Learning (ML) engine based on the random undersampling boosting algorithm and fuzzy logic, which can detect when a client is close to a freeze and drive the network prioritization to avoid it. This decision is based on measurements collected from the network nodes only, without any knowledge on the streamed videos or on the clients' characteristics. In this paper, we detail the design of the proposed ML-based framework and compare its performance with other benchmarking HAS solutions, under various video streaming scenarios. Particularly, we show through extensive experimentation that the proposed approach can reduce video freezes and freeze time with about 65% and 45% respectively, when compared to benchmarking algorithms. These results represent a major improvement for the QoE of the users watching multimedia content online
Global-Scale Resource Survey and Performance Monitoring of Public OGC Web Map Services
One of the most widely-implemented service standards provided by the Open
Geospatial Consortium (OGC) to the user community is the Web Map Service (WMS).
WMS is widely employed globally, but there is limited knowledge of the global
distribution, adoption status or the service quality of these online WMS
resources. To fill this void, we investigated global WMSs resources and
performed distributed performance monitoring of these services. This paper
explicates a distributed monitoring framework that was used to monitor 46,296
WMSs continuously for over one year and a crawling method to discover these
WMSs. We analyzed server locations, provider types, themes, the spatiotemporal
coverage of map layers and the service versions for 41,703 valid WMSs.
Furthermore, we appraised the stability and performance of basic operations for
1210 selected WMSs (i.e., GetCapabilities and GetMap). We discuss the major
reasons for request errors and performance issues, as well as the relationship
between service response times and the spatiotemporal distribution of client
monitoring sites. This paper will help service providers, end users and
developers of standards to grasp the status of global WMS resources, as well as
to understand the adoption status of OGC standards. The conclusions drawn in
this paper can benefit geospatial resource discovery, service performance
evaluation and guide service performance improvements.Comment: 24 pages; 15 figure
Boosting in Image Quality Assessment
In this paper, we analyze the effect of boosting in image quality assessment
through multi-method fusion. Existing multi-method studies focus on proposing a
single quality estimator. On the contrary, we investigate the generalizability
of multi-method fusion as a framework. In addition to support vector machines
that are commonly used in the multi-method fusion, we propose using neural
networks in the boosting. To span different types of image quality assessment
algorithms, we use quality estimators based on fidelity, perceptually-extended
fidelity, structural similarity, spectral similarity, color, and learning. In
the experiments, we perform k-fold cross validation using the LIVE, the
multiply distorted LIVE, and the TID 2013 databases and the performance of
image quality assessment algorithms are measured via accuracy-, linearity-, and
ranking-based metrics. Based on the experiments, we show that boosting methods
generally improve the performance of image quality assessment and the level of
improvement depends on the type of the boosting algorithm. Our experimental
results also indicate that boosting the worst performing quality estimator with
two or more additional methods leads to statistically significant performance
enhancements independent of the boosting technique and neural network-based
boosting outperforms support vector machine-based boosting when two or more
methods are fused.Comment: Paper: 6 pages, 5 tables, 1 figure, Presentation: 16 slides
[Ancillary files
Synthetic Iris Presentation Attack using iDCGAN
Reliability and accuracy of iris biometric modality has prompted its
large-scale deployment for critical applications such as border control and
national ID projects. The extensive growth of iris recognition systems has
raised apprehensions about susceptibility of these systems to various attacks.
In the past, researchers have examined the impact of various iris presentation
attacks such as textured contact lenses and print attacks. In this research, we
present a novel presentation attack using deep learning based synthetic iris
generation. Utilizing the generative capability of deep convolutional
generative adversarial networks and iris quality metrics, we propose a new
framework, named as iDCGAN (iris deep convolutional generative adversarial
network) for generating realistic appearing synthetic iris images. We
demonstrate the effect of these synthetically generated iris images as
presentation attack on iris recognition by using a commercial system. The
state-of-the-art presentation attack detection framework, DESIST is utilized to
analyze if it can discriminate these synthetically generated iris images from
real images. The experimental results illustrate that mitigating the proposed
synthetic presentation attack is of paramount importance.Comment: International Joint Conference on Biometrics 201
On the Challenges and KPIs for Benchmarking Open-Source NFV MANO Systems: OSM vs ONAP
NFV management and orchestration (MANO) systems are being developed to meet
the agile and flexible management requirements of virtualized network services
in the 5G era and beyond. In this regard, ETSI ISG NFV has specified a standard
NFV MANO system that is being used as a reference by MANO system vendors as
well as open-source MANO projects. However, in the absence of MANO specific
KPIs, it is difficult for users to make an informed decision on the choice of
the MANO system better suited to meet their needs. Given the absence of any
formal MANO specific KPIs on the basis of which a performance of a MANO system
can be quantified, benchmarked and compared, users are left with simply
comparing the claimed feature set. It is thus the motivation of this paper to
highlight the challenges of testing and validating MANO systems in general, and
propose MANO specific KPIs. Based on the proposed KPIs, we analyze and compare
the performance of the two most popular open-source MANO projects, namely ONAP
and OSM, using a complex open-source vCPE VNF and identify the
features/performance gaps. In addition, we also provide a sketch of a test-jig
that has been designed for benchmarking MANO systems.Comment: 12 pages, 11 figure
Towards Data-driven Simulation of End-to-end Network Performance Indicators
Novel vehicular communication methods are mostly analyzed simulatively or
analytically as real world performance tests are highly time-consuming and
cost-intense. Moreover, the high number of uncontrollable effects makes it
practically impossible to reevaluate different approaches under the exact same
conditions. However, as these methods massively simplify the effects of the
radio environment and various cross-layer interdependencies, the results of
end-to-end indicators (e.g., the resulting data rate) often differ
significantly from real world measurements. In this paper, we present a
data-driven approach that exploits a combination of multiple machine learning
methods for modeling the end-to-end behavior of network performance indicators
within vehicular networks. The proposed approach can be exploited for fast and
close to reality evaluation and optimization of new methods in a controllable
environment as it implicitly considers cross-layer dependencies between
measurable features. Within an example case study for opportunistic vehicular
data transfer, the proposed approach is validated against real world
measurements and a classical system-level network simulation setup. Although
the proposed method does only require a fraction of the computation time of the
latter, it achieves a significantly better match with the real world
evaluations
Listening to Chaotic Whispers: A Deep Learning Framework for News-oriented Stock Trend Prediction
Stock trend prediction plays a critical role in seeking maximized profit from
stock investment. However, precise trend prediction is very difficult since the
highly volatile and non-stationary nature of stock market. Exploding
information on Internet together with advancing development of natural language
processing and text mining techniques have enable investors to unveil market
trends and volatility from online content. Unfortunately, the quality,
trustworthiness and comprehensiveness of online content related to stock market
varies drastically, and a large portion consists of the low-quality news,
comments, or even rumors. To address this challenge, we imitate the learning
process of human beings facing such chaotic online news, driven by three
principles: sequential content dependency, diverse influence, and effective and
efficient learning. In this paper, to capture the first two principles, we
designed a Hybrid Attention Networks to predict the stock trend based on the
sequence of recent related news. Moreover, we apply the self-paced learning
mechanism to imitate the third principle. Extensive experiments on real-world
stock market data demonstrate the effectiveness of our approach
Uncovering the Social Interaction in Swarm Intelligence with Network Science
Swarm intelligence is the collective behavior emerging in systems with
locally interacting components. Because of their self-organization
capabilities, swarm-based systems show essential properties for handling
real-world problems such as robustness, scalability, and flexibility. Yet, we
do not know why swarm-based algorithms work well and neither we can compare the
different approaches in the literature. The lack of a common framework capable
of characterizing these several swarm-based algorithms, transcending their
particularities, has led to a stream of publications inspired by different
aspects of nature without a systematic comparison over existing approaches.
Here, we address this gap by introducing a network-based framework---the
interaction network---to examine computational swarm-based systems via the
optics of the social dynamics of such interaction network; a clear example of
network science being applied to bring further clarity to a complicated field
within artificial intelligence. We discuss the social interactions of four
well-known swarm-based algorithms and provide an in-depth case study of the
Particle Swarm Optimization. The interaction network enables researchers to
study swarm algorithms as systems, removing the algorithm particularities from
the analyses while focusing on the structure of the social interactions.Comment: 23 pages, 6 figure
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