14,942 research outputs found
A predefined channel coefficients library for vehicle-to-vehicle communications
It is noticeable that most of VANETs communications tests are assessed through simulation. In a majority of simulation results, the physical layer is often affected by an apparent lack of realism. Therefore, vehicular channel model has become a critical issue in the field of intelligent transport systems (ITS). To overcome the lack of realism problem, a more robust channel model is needed to reflect the reality. This paper provides an open access, predefined channel coefficients library. The library is based on 2x2 and 4x4 Multiple – Input – Multiple – Output (MIMO) systems in V2V communications, using a spatial channel model extended SCME which will help to reduce the overall simulation time. In addition, it provides a more realistic channel model for V2V communications; considering: over ranges of speeds, distances, multipath signals, sub-path signals, different angle of arrivals, different angle departures, no line of sight and line of sight. An intensive evaluation process has taken place to validate the library and acceptance results are produced. Having an open access predefined library, enables the researcher at relevant communities to test and evaluate several complicated vehicular communications scenarios in a wider manners with less time and efforts
The antimicrobial activity of oil-in-water microemulsions is predicted by their position within the microemulsion stability zone
It has been shown previously that thermodynamically stable oil-in-water microemulsions have significant antimicrobial activity against planktonic cells and biofilm cells over short periods of exposure. It was the aim of this study to identify whether the position of the microemulsion within the microemulsion stability zone of the pseudo-ternary phase structure predicts the efficiency of the antimicrobial action of the microemulsion. Microemulsions were formulated at different points within the microemulsion stability zone. Experiments were performed to observe the kinetics of killing of these microemulsions against selected test microorganisms (Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 10231, Staphylococcus aureus ATCC 6538 and Aspergillus niger ATCC 16404). The results indicated that the antimicrobial activity of the microemulsion is dependant upon its position within the zone of stability and is greater nearer the centre of that zone. The results indicate that significant antimicrobial activity can be observed at all points within the zone of microemulsion stability, but that maximal activity is to be found at the centre of that area
Sub 1GHz M2M communications standardization: The advancement in white space utilization for enhancing the energy efficiency
Energy efficiency of machine to machine (M2M) communications terminals is one of the major design goals of M2M networks, resulting from anticipated over 50 billion M2M communications devices to be deployed into the networks by 2020 [1]. The stakeholders in the M2M communications have observed that it will be environmental and economic catastrophic to deploy M2M communications devices without solving the energy inefficiencies associated with wireless devices that are expected to be used for M2M communications. In view of the aforementioned energy challenge, sub 1GHz spectra have provided enormous opportunities that can be energy efficient, cost effective and coverage efficiency which can be utilized for M2M communications. This work will evaluate the energy efficiency benefits of optimized Sub 1GHz spectra for M2M communications
Banking sector depth & long-term economic growth in the GCC States: relationship nature, sector development status & policy implications
The thesis investigates the nature of the relationship between the banking sector depth and long-term economic growth in the Gulf Cooperation Council (GCC) States, assesses the banking sector development status in each of the States, and underlines the policy implications in the light of the banking-growth nexus and the banking development benchmarking models’ findings for the region by undertaking three projects.
The thesis examines the nature of the relationship between banking sector depth and long-term economic growth in the NRBC—as a proxy for the GCC States— vis-à -vis the rest of the world countries. For the empirical investigation, a dynamic panel data approach, i.e. Generalised Method of Moments (GMM), is adopted over the period 1961 to 2013. By utilising mixed effects and System GMM frameworks, the research identifies the countries with the strongest banking-growth relationships and establishes the banking sector development determinants in those countries. Employing a novel benchmarking process, the thesis assesses the status of the banking sector development in each of the GCC member countries and simulates the change in the banking sector depth across the Gulf region over a period of ten years to highlight the potential policy implications for the sector development.
The findings of the thesis suggest that the relationship between banking sector depth and long-term economic growth in the NRBC is non-linear, where the relationship between the banking sector depth and economic growth turns from positive to negative beyond certain levels of sector depth. In comparison to other countries, the results indicate that the banking-growth nexus in the NRBC exhibits a smaller total effect magnitude as well as a shorter time between the change in the sector depth and its effect on economic growth. The benchmarking of the banking sectors in the GCC region suggests that in five of the six member countries the banking sectors are underdeveloped. The simulation results predict that the banking sectors will develop further in half of the countries in the region, given their current levels of banking sector development determinants, while two countries require reforms in terms of undertaking regulations and policies to avoid seeing their sector development levels deteriorate.
The thesis contributes to theory by confirming findings in the literature and expanding the body of knowledge through novel findings. This research also contributes to policy by demonstrating the significance of the banking sector development for long-term economic growth in the NRBC, providing policymakers in the Gulf States with the status of their banking sectors, and underlining the banking sector depth determinants that ought to be considered when setting regulations and policies that are aimed at developing the banking sector further
Information behaviour of researchers at Sultan Qaboos University
The present study investigates the information gathering behaviour of the academic researchers at Sultan Qaboos University in the Sultanate of Oman. It endeavours to explore researchers' awareness and attitudes towards information sources and services. Research methods for this study were designed from the user-centred
perspective with triangulation approach. Hence, data was collected by the use of semistructured
interviews as the main instrument with journal study and observation as
supplementary tools. The information was collected from the members of the research
community in their capacity as users of information.
The study investigates the information needs and information gathering habits of the
research community and attempts to identify the problems experienced by researchers
in accessing and using information. It also seeks to explore the national policy for
planning and provision of information. Finally the study examines the performance of
the various information services in the context of user needs and the status of the
institution library information service provision.
The research concludes that present information environment at Sultan Qaboos
University is inadequate to meet the information needs of the research community. It
was found that the major causes for the situation was the lack of clear information
policies, inadequate funding, ineffective partnership between top management and
academic researchers, lack of effective in house training and finally absence of a reliable information technology infrastructure
Some statistical methods for dimension reduction
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel UniversityThe aim of the work in this thesis is to carry out dimension reduction (DR) for high dimensional (HD) data by using statistical methods for variable selection, feature extraction and a combination of the two. In Chapter 2, the DR is carried out through robust feature extraction. Robust canonical correlation (RCCA) methods have been proposed. In the correlation matrix of canonical correlation analysis (CCA), we suggest that the Pearson correlation should be substituted by robust correlation measures in order to obtain robust correlation matrices. These matrices have been employed for producing RCCA. Moreover, the classical covariance matrix has been substituted by robust estimators for multivariate location and dispersion in order to get RCCA. In Chapter 3 and 4, the DR is carried out by combining the ideas of variable selection using regularisation methods with feature extraction, through the minimum average variance estimator (MAVE) and single index quantile regression (SIQ) methods, respectively. In particular, we extend the sparse MAVE (SMAVE) reported in (Wang and Yin, 2008) by combining the MAVE loss function with different regularisation penalties in Chapter 3. An extension of the SIQ of Wu et al. (2010) by considering different regularisation penalties is proposed in Chapter 4. In Chapter 5, the DR is done through variable selection under Bayesian framework. A flexible Bayesian framework for regularisation in quantile regression (QR) model has been proposed. This work is different from Bayesian Lasso quantile regression (BLQR), employing the asymmetric Laplace error distribution (ALD). The error distribution is assumed to be an infinite mixture of Gaussian (IMG) densities
Service level agreement framework for differentiated survivability in GMPLS-based IP-over-optical networks
In the next generation optical internet, GMPLS based IP-over-optical networks, ISPs will be required to support a wide variety of applications each having their own requirements. These requirements are contracted by means of the SLA. This paper describes a recovery framework that may be included in the SLA contract between ISP and customers in order to provide the required level of survivability. A key concern with such a recovery framework is how to present the different survivability alternatives including recovery techniques, failure scenario and layered integration into a transparent manner for customers. In this paper, two issues are investigated. First, the performance of the recovery framework when applying a proposed mapping procedure as an admission control mechanism in the edge router considering a smart-edge simple-core GMPLS-based IP/WDM network is considered. The second issue pertains to the performance of a pre-allocated restoration and its ability to provide protected connections under different failure scenarios
Employing VANET technology to alleviate road congestion in real time
Nowadays, traffic road jams are considered one of the most serious problems facing a large group of people, where many drivers die or are exposed to serious injuries because of road accidents that occur due to road congestion, driver's behaviour by disobeying the rules and traffic lights or bad management for traffic system. The eagerness on developing the deployment traffic road information among vehicles to reduce road accident and to make the journey more safe was the main motivation behind the improvement of Vehicular Ad Hoc Networks VANETs. VANETs are a special category of Mobile Ad Hoc Networks (MANET), which considered the cornerstone for Intelligent Transportation System (ITS) that used to established communication among vehicles on a road using an infrastructure-less network. On this study, we will use graph model representation to design a novel algorithm which can deal with Instantaneous accident/incident occasions, road works and roads amendments to provide instant actions list to the transportation team to reduce congestion in shorter time, and to use wireless access technologies to send individual message to the relevant vehicles to avoid the congestion through Road Side Units (RSUs) devices. The aim of this research is to develop Intelligent Transportation System (ITS) for a city (e.g. Northampton) using VANETs technology, specifically vehicle to infrastructure communications which lead to reducing the traffic congestion or mitigation. The performance of proposed study will be evaluated via various congested scenarios using simulations software (Omnet++, SUMO and Veins) to assess the validity of the proposed algorithm
Enhancement of Pavement Condition and Its Impact on Pavement Sustainability: Environmental and Economic Assessments
The cost saving regarding vehicles operation, travel time and road maintenance has one eye-catching benefit via increasing pavement sustainability through maintaining the material sources and reducing the emissions of gases resulted from the processing of derivative products. Furthermore, the rate of increase of traffic on unpaved road is considered as a strong indicator to construct paved roads over this area.  In the present paper, the Nasiriya-Abu Ghar road was studied. It is one of the important unpaved roads. Its importance lies in the transport of construction materials from Abu Ghar quarries to the near provinces in Iraq, such as Dhi Qar Province. Abu Ghar quarries are considered as one of the most important quarries because it contains different construction materials such as gravel, limestone and sand. These materials have high engineering properties. Thus, the absence of a paved road linking Abu Ghar quarries with the surrounding areas, especially the province of Dhi Qar, encouraged to conduct a technical and economic feasibility study to highlight it and to help the decision-makers to implement the project. The present study contributes in statement of the economic and environmental feasibility of the construction of a new suggested road over the old unpaved one. The study depends on the hypothesis that the old road has a bad condition while the new one is an asphaltic concrete pavement with a good condition. The manual counting method of traffic volume was used from 7:00 am to 4:00 pm for 7 days to determine the peak hour volume and average daily traffic. Road's construction and maintenance costs were estimated. Saving in the road user costs for both existing (old) and new-suggested roads were calculated to be considered as benefits. The economic study is achieved by comparing the discounted total road costs and their benefits to the basic year (starting year of the project). In the present study, the adopted discount rate is 8%. To find the economic feasibility, some criteria were tested. These criteria are: Net Present Value (NPV), Benefit–Cost Ratio (B/C) and Internal Rate of Return (IRR). The results show that NPV has a positive value equals to 40,269,371 US$, which means that benefits are greater than costs. Furthermore, B/C ratio was 2.54; comparing with a value of 1.0, which is encouraging. Finally, the IRR was located between discount rates of 20% and 25 %, with a value of 22.9% which is higher than 8% "the recommended in the road projects". Keywords: Pavement Condition, Road User Costs, Economic Feasibility, Benefit –Cost Ratio (B/C), Pavement Sustainability
Banking sector depth and economic growth nexus: a comparative study between the natural resource-based and the rest of the world’s economies
This paper investigates the relationship between banking sector depth and long-term economic growth in the natural resource based economies vis-Ă -vis economies that are not dependent on natural resources. For the empirical investigation, a Generalised Method of Moments (GMM) estimator for dynamic panel-data models is adopted for 194 countries spanning the period 1964 to 2013. By using different measures of banking sector depth and economic growth, the investigation yields three key findings. First, the banking-growth relationship is non-linear and positive within certain levels of banking sector depth in both country groups. Second, the time lag between the change in the level of banking sector depth and the effect on economic growth is shorter in the natural resource-based countries than in the other countries. Finally, the total effect of banking sector deepening on long-term economic growth is weaker in economies with abundant natural resources than in the rest of the world
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