1,023 research outputs found
Winnowing ontologies based on application use
The requirements of specific applications and services are often over estimated when ontologies are reused or built. This sometimes results in many ontologies being too large for their intended purposes. It is not uncommon that when applications and services are deployed over an ontology, only a few parts of the ontology are queried and used. Identifying which parts of an ontology are being used could be helpful to winnow the ontology, i.e., simplify or shrink the ontology to smaller, more fit for purpose size. Some approaches to handle this problem have already been suggested in the literature. However, none of that work showed how ontology-based applications can be used in the ontology-resizing process, or how they might be affected by it. This paper presents a study on the use of the AKT Reference Ontology by a number of applications and services,and investigates the possibility of relying on this usage information to winnow that ontology
Identification as a deterrent for security enhancement in cognitive radio networks
Cognitive Radio Networks (CRNs) are prone to emerging coexistence security threats such as Primary User Emulation Attack (PUEA). Specifically, a malicious CRN may mimic licensees’ (Primary Users (PUs)) signal characteristics to force another CRN to vacate its channels thinking that PUs have returned. While existing schemes are promising to some extent on detecting PUEAs, they are not able to prevent the attacks. In this article, we propose a PUEA Deterrent (PUED) algorithm that can provide PUEAs' commission details: offender CRNs and attacks’ time and bandwidth. There are many similarities between PUED and Closed-Circuit Television (CCTV) in terms of: deterrence strategy, reason for use, surveillance characteristics, surveillance outcome, and operation site. According to the criminology literature, robust CCTV systems have shown a significant reduction in visible offences (e.g. vehicle theft), reducing crime rates by 80%. Similarly, PUED will contribute the same effectiveness in deterring PUEAs. Furthermore, providing PUEAs’ details will prevent the network’s cognitive engine from considering the attacks as real PUs, consequently avoiding devising unreliable spectrum models for the attacked channels. Extensive simulations show the effectiveness of the PUED algorithm in terms of improving CRNs’ performance
Comprehensive survey on quality of service provisioning approaches in cognitive radio networks : part one
Much interest in Cognitive Radio Networks (CRNs) has been raised recently by enabling unlicensed (secondary) users to utilize the unused portions of the licensed spectrum. CRN utilization of residual spectrum bands of Primary (licensed) Networks (PNs) must avoid harmful interference to the users of PNs and other overlapping CRNs. The coexisting of CRNs depends on four components: Spectrum Sensing, Spectrum Decision, Spectrum Sharing, and Spectrum Mobility. Various approaches have been proposed to improve Quality of Service (QoS) provisioning in CRNs within fluctuating spectrum availability. However, CRN implementation poses many technical challenges due to a sporadic usage of licensed spectrum bands, which will be increased after deploying CRNs. Unlike traditional surveys of CRNs, this paper addresses QoS provisioning approaches of CRN components and provides an up-to-date comprehensive survey of the recent improvement in these approaches. Major features of the open research challenges of each approach are investigated. Due to the extensive nature of the topic, this paper is the first part of the survey which investigates QoS approaches on spectrum sensing and decision components respectively. The remaining approaches of spectrum sharing and mobility components will be investigated in the next part
Social dynamics in conferences: analyses of data from the Live Social Semantics application
Popularity and spread of online social networking in recent years has given a great momentum to the study of dynamics and patterns of social interactions. However, these studies have often been confined to the online world, neglecting its interdependencies with the offline world. This is mainly due to the lack of real data that spans across this divide. The Live Social Semantics application is a novel platform that dissolves this divide, by collecting and integrating data about people from (a) their online social networks and tagging activities from popular social networking sites, (b) their publications and co-authorship networks from semantic repositories, and (c) their real-world face-to-face contacts with other attendees collected via a network of wearable active sensors. This paper investigates the data collected by this application during its deployment at three major conferences, where it was used by more than 400 people. Our analyses show the robustness of the patterns of contacts at various conferences, and the influence of various personal properties (e.g. seniority, conference attendance) on social networking patterns
Virtual Machines Embedding for Cloud PON AWGR and Server Based Data Centres
In this study, we investigate the embedding of various cloud applications in
PON AWGR and Server Based Data Centres
TESTABILITY OF INFORMATION LEAK IN THE SOURCE CODE FOR INDEPENDENT TEST ORGANIZATION BY USING BACK PROPAGATION ALGORITHM
A strategy for software testing integrates the design of software test cases into a wellplanned series of steps that results in a successful development of the software security. The strategy provides the secure source code test by Independent Test Organization (ITO) that describes the steps to be taken, when, and how much effort, time, and resources will be required. The strategy incorporates test planning, test case design, test execution, test result collection and test leak information and evaluation. In this work we speak about the testability of leak information in source code and how to detect and protect it inside the ITO. In this paper we present a privacy preserving algorithm for the neural network learning to detect and protect the leak information in source code between two parties the programmer (source code) and Independent Test Organization (Sensor). We show that our algorithm is very secure and the sensor inside Independent Test Organization is able to detect and protect all leaks information inside the source code. We demonstrate the efficiency of our algorithm by experiments on real world data. We present new technology for software Security using Back Propagation algorithm. That is embedded sensor to analyze the source code inside the ITO. By using embedded sensor we can detect and protect in real time all the attacks or leaks of information inside the source code. The connection between an Artificial Neural Networks and source code analysis inside Independent Test Organization is providing a great help for the software security
A new processing approach for reducing computational complexity in cloud-RAN mobile networks
Cloud computing is considered as one of the key drivers for the next generation of mobile
networks (e.g. 5G). This is combined with the dramatic expansion in mobile networks, involving millions
(or even billions) of subscribers with a greater number of current and future mobile applications
(e.g. IoT). Cloud Radio Access Network (C-RAN) architecture has been proposed as a novel concept to
gain the benefits of cloud computing as an efficient computing resource, to meet the requirements of future
cellular networks. However, the computational complexity of obtaining the channel state information in
the full-centralized C-RAN increases as the size of the network is scaled up, as a result of enlargement in
channel information matrices. To tackle this problem of complexity and latency, MapReduce framework
and fast matrix algorithms are proposed. This paper presents two levels of complexity reduction in the
process of estimating the channel information in cellular networks. The results illustrate that complexity
can be minimized from O(N3) to O((N/k)3), where N is the total number of RRHs and k is the number of
RRHs per group, by dividing the processing of RRHs into parallel groups and harnessing the MapReduce
parallel algorithm in order to process them. The second approach reduces the computation complexity
from O((N/k)3) to O((N/k)2:807) using the algorithms of fast matrix inversion. The reduction in complexity
and latency leads to a significant improvement in both the estimation time and in the scalability of
C-RAN networks
Miniaturized UWB elliptical patch antenna for skin cancer diagnosis imaging
The biomedical imaging shows promising results in many applications such as protein characterization and cancer detection using non-ionizing radiation. Skin cancer is one of the most common types of cancer because it is exposed by sun rays during the day. Many techniques have been offered to detect the tumor in the early stage such as ultrasonic and MW imaging. However, most of these studies showed a large printing area with lower BW so as the low resolution. To overcome these drawbacks, a new low profile UWB elliptical patch antenna with high performance is designed on PTFE as a substrate. Then a layer of Indium Tin Oxide (ITO) applies to improve the antenna radiation characteristics. The proposed antenna has a broad BW from 3.9 GHz to 30 GHz along with a resonance at 2.4 GHz. Furthermore, the antenna presents a maximum gain of 7.3 dB, maximum directivity of 7.78 dBi, the maximum radiation efficiency of 92 %, and consistent, stable radiation pattern throughout the frequency band. Besides, the time-domain characteristics show that the antenna can be a suitable candidate for microwave imaging of skin cancer
Semantics, sensors, and the social web: The live social semantics experiments
The Live Social Semantics is an innovative application that encourages and guides social networking between researchers at conferences and similar events. The application integrates data and technologies from the Semantic Web, online social networks, and a face-to-face contact sensing platform. It helps researchers to find like-minded and influential researchers, to identify and meet people in their community of practice, and to capture and later retrace their real-world networking activities at conferences. The application was successfully deployed at two international conferences, attracting more than 300 users in total. This paper describes this application, and discusses and evaluates the results of its two deployment
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