63 research outputs found

    Identifying cloud security threats to strengthen cloud computing adoption framework

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    Cloud Computing allows firms to outsource their entire information technology (IT) process, allowing them to concentrate more on their core business to enhance their productivity and innovation in offering services to customers. It allows businesses to cut down heavy cost incurred over IT infrastructure without losing focus on customer needs. However, to a certain limit adopting Cloud computing has struggled to grow among many established and growing organizations due to several security and privacy related issues. Throughout the course of this study several interviews were conducted, with cloud developers and security experts, and the literature was reviewed. This study enabled us to understand, current and future, security and privacy challenges with cloud computing. The outcome of this study led to identification of total 18, current and future, security issues affecting several attributes of cloud computing

    Numerical Study of Cuttings Transport of Nanoparticle-Based Drilling Fluid

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    Cuttings transportation from the drill bit, through the annulus, to the surface is one of the most important functions performed by drilling fluid. The prediction of drilling fluid's performance to transport cuttings in the annulus is very complex task due to the presence of numerous parameters. Nanoparticles (NPs) have been recently introduced into drilling fluid to engineer its properties and enhance its performance. Nevertheless, the lifting capacity has not been sufficiently investigated. The understanding of the influence and the mechanisms responsible for the improvement in cuttings transport process can further advance the application of NPs for drilling fluids. Computational fluid dynamics (CFD) is widely used as a numerical technique in handling complex multiphase flow problems in different operational conditions. The present work has taken the advantages of CFD to computationally analyze the influence of NPs and the effects of various parameters such as drilling fluids rheology, flow rate, pipe rotation, cuttings density, shape, concentration, and drilling fluids-cuttings particle coupling regimes on the cuttings transport in a vertical wellbore. The CFD simulation is carried out by using transient solver of ANSYS-FLUENT commercial code. The dense discrete phase model is used to overcome the main shortcomings of previous Eulerian based approaches. Good agreement has been achieved between the simulation and the published experimental results. It showed that the fluid viscosity and cuttings transport process can be significantly enhanced by adding nanomaterials to the fluid, and the process is highly influenced by cuttings characteristics such as in situ concentration, shape, and density

    SenNet : a programming toolkit to develop wireless sensor network applications

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    One of the reasons that Wireless Sensor Network(WSN) applications are not widely available is the complexity in their development. This is a consequence of the complex nature in low-level details, which a developer must manage. The vast majority of the present application developments are done using node-centric low-level languages, for example, C. In order to make the WSN technology more universal; application development complexity nature should be reduced, and development efficiency increased. This paper describes SenNet language, which is a new approach to WSN application development using a Domain-Specific Language (DSL). SenNet empowers application developers to focus on modelling the application logic using domain specific terms. The new approach gives the ability to write applications using multi-levels of abstraction (i.e. network, group, and node-level). Evaluation results show that SenNet decreases the cognitive effort required for learning WSN application development in addition to the time required to write the application by using automated code generation from abstracted language commands

    A new processing approach for reducing computational complexity in cloud-RAN mobile networks

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    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

    A NEW PROTOCOL TO DESIGN CELLULAR SYSTEMS WITH VARIABLE SPREADING FACTORS

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    The emerging M-commerce (mobile +e-commerce) needs more support in operating systems in order to be successful over a wireless environment. The system needs to support a seamlessintegrati n to support voice, audio and conventional data. It should also support many users with guaranteed quality. In this paper, a new effective design protocol for Code Division Multiple Access(CDMA) mobile systems with Variable Spreading Factor (VSF) is presented, such that various Quality of Service (QoS) based on different traffic types can be provided. Increasing spreading factors can benefit the system because it will increase the desired signal strength linearly. The measured Bit Error Rate (BER) can be reduced 75 times with a long spreading factor. By taking advantage of this benefit, switching the spreading factors dynamically is proposed, based on the current load with multimedia traffic.These proposals are implemented in mobile and base stations, and the system performance measured. The results indicated that the proposed system can always maintain a desired quality forall voice connections

    Comparative Study of Building Envelope Cooling Loads in Al-Amarah City, Iraq

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    In recent years, the summer season in Iraq has become longer and hotter than before, leading to high cooling loads inside buildings and increased demand for electrical energy. The use of sustainable energy and insulation techniques for building envelopes are reasonable solutions for overcoming harsh weather conditions and reaching acceptable thermal comfort levels. In this study, a survey on more than 60 residential buildings in Al-Amarah City, Iraq, was conducted on 21 July 2018 to examine the nature of the most common construction materials used in the building envelopes. Furthermore, the cooling loads of building envelope elements, e.g. roof, external walls and windows, was calculated using the cooling load temperature difference/solar cooling load/cooling load factor method of ASHRAE. The results were tabulated and compared for each combination of elements. The results showed that reflective glass is the optimal choice for exterior windows. The 'clay"“insulation"“fired clay bricks"“cement mortar' and 'cement mortar"“thermo-stone bricks"“cement mortar"“gypsum mortar' combination layers performed well for roof and external wall installations, respectively. Several recommendations were deduced from this study, which can be used as guidelines for construction authorities in Al-Amarah City and individuals interested in energy-efficient buildings

    Domain oriented object reuse based on genetic software architectures.

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    In this thesis, a new systematic approach is introduced for developing software systems from domain-oriented components. The approach is called Domain Oriented Object Reuse (DOOR) which is based on domain analysis and Generic Software Architectures. The term 'Generic Software Architectures' is used to denote a new technique for building domain reference architectures using architecture schemas. The architecture schemas are used to model the components behaviour and dependency. Components dependencies describe components behaviour in terms of their inter-relationships within the same domain scope. DOOR uses the architecture schemas as a mechanism for specifying design conceptions within the modelled domain. Such conceptions provide design decisions and solutions to domain-specific problems which may be applied in the development of new systems. Previous research in the area of domain analysis and component-oriented reuse has established the need for a systematic approach to component-oriented development which emphasises the presentation side of the solution in the technology. DOOR addresses the presentation issue by organising the domain knowledge into levels of abstractions known to DOOR as sub-domains. These levels are organised in a hierarchical taxonomy tree which contains, in addition to sub-domains, a collection of reusable assets associated with each level. The tree determines the scope of reuse for every domain asset and the boundaries for their application. Thus, DOOR also answers the questions of reuse scope and domain boundaries which have also been raised by the reuse community. DOOR's reuse process combines development for reuse and development with reuse together. With this process, which is supported by a set of integrated tools, a number of guidelines have been introduced to assist in modelling the domain assets and assessing their reusability. The tools are also used for automatic assessment of the domain architecture and the design conceptions of its schemas. Furthermore, when a new system is synthesised, components are retrieved, with the assistance of the tools, according to the scope of reuse within which the system is developed. The retrieval procedure uses the components dependencies for tracing and retrieving the relevant components for the required abstraction

    Security-oriented cloud computing platform for critical infrastructures

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    The rise of virtualisation and cloud computing is one of the most significant features of computing in the last 10 years. However, despite its popularity, there are still a number of technical barriers that prevent it from becoming the truly ubiquitous service it has the potential to be. Central to this are the issues of data security and the lack of trust that users have in relying on cloud services to provide the foundation of their IT infrastructure. This is a highly complex issue, which covers multiple inter-related factors such as platform integrity, robust service guarantees, data and network security, and many others that have yet to be overcome in a meaningful way. This paper presents a concept for an innovative integrated platform to reinforce the integrity and security of cloud services and we apply this in the context of Critical Infrastructures to identify the core requirements, components and features of this infrastructure

    Data aggregation in wireless sensor networks using the SOAP protocol

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    Wireless sensor networks (WSN) offer an increasingly attractive method of data gathering in distributed system architectures and dynamic access via wireless connectivity. Wireless sensor networks have physical and resource limitations, this leads to increased complexity for application developers and often results in applications that are closely coupled with network protocols. In this paper, a data aggregation framework using SOAP (Simple Object Access Protocol) on wireless sensor networks is presented. The framework works as a middleware for aggregating data measured by a number of nodes within a network. The aim of the study is to assess the suitability of the protocol in such environments where resources are limited compared to traditional networks
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