Analysis of outsourcing data to the cloud using autonomous key generation

Cloud computing, a technology that enables users to store and manage their data at a low cost and high availability, has been emerging for the past few decades because of the many services it provides. One of the many services cloud computing provides to its users is data storage. The majority of the users of this service are still concerned to outsource their data due to the integrity and confidentiality issues, as well as performance and cost issues, that come along with it. These issues make it necessary to encrypt data prior to outsourcing it to the cloud. However, encrypting data prior to outsourcing makes searching the data obsolete, lowering the functionality of the cloud. Most existing cloud storage schemes often prioritize security over performance and functionality, or vice versa. In this thesis, the cloud storage service is explored, and the aspects of security, performance, and functionality are analyzed in order to investigate the trade-offs of the service. DSB-SEIS, a scheme with encryption intensity selection, an autonomous key generation algorithm that allows users to control the encryption intensity of their files, as well as other features is developed in order to find a balance between performance, security, and functionality. The features that DSB-SEIS contains are deduplication, assured deletion, and searchable encryption. The effect of encryption intensity selection on encryption, decryption, and key generation is explored, and the performance and security of DSB-SEIS are evaluated. The MapReduce framework is also used to investigate the DSB-SEIS algorithm performance with big data. Analysis demonstrates that the encryption intensity selection algorithm generates a manageable number of encryption keys based on the confidentiality of data while not adding significant overhead on encryption or decryption --Abstract, page iii

The Identity and Cultural Dimensions of the Iconic Pedestrian Territory Using Comparative Territorialism Comparison Between Broadway at Times Square, NYC (USA), Las Ramblas De Barcelona (Spain) and İstiklal Caddesi, Istanbul (Turkey)

Although territory has mainly been used in a political context, this thesis revisits the term to show how it can be multifaceted in a broader geographical context, and used to understand cultural and urban issues. The key argument of the thesis is the conceptualisation of the pedestrian street as a pedestrian territory and the application of this concept to iconic pedestrian streets that are tourism and entertainment destinations with unique historic and locational value, revealing the drivers and powers used to transform such territories in the last few decades as traveling practices of globalisation, neoliberalism and tourism. Theoretically, relationality is used to investigate sociocultural patterns between the pedestrian territories of Las Ramblas, Times Square and İstiklal Avenue and methodologically, comparative territorialism is used to distinguish between human and place cultures and identities. Both theoretical and empirical findings were used to chronologically track the transformation of these streets to a territories using three key approaches; subjectively use people’ sensations, affects, perceptions, expressions and conceptions to define the relationship between the human and non-human through territoriality; thematically draw distinctions between human culture and place culture in creating territorial culture; and analytically reveal the reasons behind this territorial identity, this experiential uniqueness. Three themes emerged; an intensive commercialisation and uneven creation of and simultaneous loss of public space, an opening up of opportunities for tolerance and freedom of expression alongside purposeful law-breaking, and the possibilities and tensions arising from the global/local identity crisis. The research reveals how the money and resources that are poured into pedestrian territories to attract symbolic attention contributes to their iconic status, but risks provoking conflicts on different levels, such as political protests, social tensions, cultural clashes and even major incidents

Theoretical analysis of some thin-film flows over complex surfaces

In this thesis, three different aspects of thin-film flow over complex surfaces are investigated. First, locally-unidirectional rivulet flow on a slippery surface is considered. We study rivulets with prescribed flux and either fixed semi-width or fixed contact angle. In both cases we determined the effect of varying the slip length on the rivulet. We found that in the limit of strong slip, for a rivulet of a perfectly wetting fluid and a rivulet with constant = width, the velocity becomes large and plug-like, and the rivulet becomes shallow, while for a rivulet with positive constant contact angle, the velocity becomes large and plug-like, and the rivulet becomes narrow and shallow. Second, rivulet flow over and through a permeable membrane is considered. We study rivulets with prescribed flux and either fixed semi-width or fixed contact angle. We found that whereas there is a physically realisable pendant rivulet solution only if the semi-width does not exceed a critical value, there are physically realisable sessile and vertical rivulet solutions for all values of the semi-width; moreover, a sessile rivulet with fixed semi-width has a finite maximum possible length which is attained in the limit of a wide rivulet. Lastly, patterns formed in a two-dimensional thin film with a Derjaguin-type disjoining pressure on a planar substrate with periodic wettability stripes is considered. Using Liapunov–Schmidt reduction, we study the local bifurcation structure of the problem for spatially homogeneous disjoining pressure and how the structure depends on the average film thickness. Using methods of local bifurcation theory and the continuation software package AUTO, we perform a continuation analysis of the steady state solutions and establish the existence of both nucleation and metastable regimes. The dependence of the steady state solutions on the wettability contrast are investigated for two forms of spatially non-homogeneous disjoining pressure.In this thesis, three different aspects of thin-film flow over complex surfaces are investigated. First, locally-unidirectional rivulet flow on a slippery surface is considered. We study rivulets with prescribed flux and either fixed semi-width or fixed contact angle. In both cases we determined the effect of varying the slip length on the rivulet. We found that in the limit of strong slip, for a rivulet of a perfectly wetting fluid and a rivulet with constant = width, the velocity becomes large and plug-like, and the rivulet becomes shallow, while for a rivulet with positive constant contact angle, the velocity becomes large and plug-like, and the rivulet becomes narrow and shallow. Second, rivulet flow over and through a permeable membrane is considered. We study rivulets with prescribed flux and either fixed semi-width or fixed contact angle. We found that whereas there is a physically realisable pendant rivulet solution only if the semi-width does not exceed a critical value, there are physically realisable sessile and vertical rivulet solutions for all values of the semi-width; moreover, a sessile rivulet with fixed semi-width has a finite maximum possible length which is attained in the limit of a wide rivulet. Lastly, patterns formed in a two-dimensional thin film with a Derjaguin-type disjoining pressure on a planar substrate with periodic wettability stripes is considered. Using Liapunov–Schmidt reduction, we study the local bifurcation structure of the problem for spatially homogeneous disjoining pressure and how the structure depends on the average film thickness. Using methods of local bifurcation theory and the continuation software package AUTO, we perform a continuation analysis of the steady state solutions and establish the existence of both nucleation and metastable regimes. The dependence of the steady state solutions on the wettability contrast are investigated for two forms of spatially non-homogeneous disjoining pressure

Improved anti-noise attack ability of image encryption algorithm using de-noising technique

Information security is considered as one of the important issues in the information age used to preserve the secret information through out transmissions in practical applications. With regard to image encryption, a lot of schemes related to information security were applied. Such approaches might be categorized into 2 domains; domain frequency and domain spatial. The presented work develops an encryption technique on the basis of conventional watermarking system with the use of singular value decomposition (SVD), discrete cosine transform (DCT), and discrete wavelet transform (DWT) together, the suggested DWT-DCT-SVD method has high robustness in comparison to the other conventional approaches and enhanced approach for having high robustness against Gaussian noise attacks with using denoising approach according to DWT. MSE in addition to the peak signal-to-noise ratio (PSNR) specified the performance measures which are the base of this study’s results, as they are showing that the algorithm utilized in this study has high robustness against Gaussian noise attacks

A novel reusable learning object development (RLO) for supporting engineering laboratory education

A novel reusable learning object development (RLO) for supporting engineering laboratory educatio

Applying Kolb’s experiential learning cycle for laboratory education

This paper describes a model for laboratory education based on Kolb’s experiential learning theory. The method is implemented using modern teaching technologies and a combination of remote, virtual, and hands-on laboratory sessions and have been applied to the teaching of the undergraduate process control laboratory at the Chemical Engineering Department at Loughborough University, United Kingdom. An argument that poor learning in the laboratory is due to insufficient activation of the prehension dimension of Kolb’s cycle was suggested and verified, providing a pedagogical explanation. The quantitative analysis showed significant enhancement of the learning outcomes of the experimental group compared with the control group. Apart from the hands-on session, the proposed model involves additional activities, such as pre- and post-lab tests and virtual laboratory sessions, which are associated with Kolb’s cycle to facilitate constructivist learning. The paper provides the first laboratory education model that builds thoroughly on Kolb’s experiential learning theory

Underwater Image De-nosing using Discrete Wavelet Transform and Pre-Whitening Filter

Image denoising and improvement are essential processes in many underwater applications. Various scientific studies, including marine science and territorial defence, require underwater exploration. When it occurs underwater, noise power spectral density is inconsistent within a certain range of frequency, and the noise autocorrelation function is not a delta function. Therefore, underwater noise is characterised as coloured noise. In this study, a novel image denoising technique is proposed using discrete wavelet transform with different basis functions and a whitening filter, which converts coloured noise characteristics to white noise prior to the denoising process. Results of the proposed method depend on the following performance measures: peak signal-to-noise ratio (PSNR) and mean squared error. The results of different wavelet bases, such as Debauchies, biorthogonal and symlet, indicate that the denoising process that uses a pre-whitening filter produces more prominent images and better PSNR values than other methods

TriLab – a combined remote, virtual and hands-on laboratory as a novel reusable learning object (RLO) for supporting engineering laboratory education

Reusable Learning Object (RLO) is, in brief, a conceptual model of a shared vessel of teaching and learning content which is normally developed using IT tools. Attention have been paid recently towards using RLOs in educational processes for facilitating better learning and minimizing costs associated with improving teaching and learning. The importance of a laboratory experience in engineering education curricula has been emphasized in a large number of science and engineering education articles (Johnstone et al 2001; Hofestein et al 2004; Feisel et al 2002; Kirschener et al 1988; Ma et al 2006). Wankat observes that only 6% of the articles published in the Journal of Engineering Education from 1993-2002 had ‘Laboratory’ as a keyword (Wankat 2004). In response to the recent recommendations in the literature regarding the engineering laboratory education, we worked on developing an Online Laboratory Learning Object (OLLO) for enhancing the students laboratory experience, the OLLO was developed for the process control laboratory taught through various courses at the chemical engineering department of Loughborough University

Constructivist Multi-Access Lab Approach in Teaching FPGA Systems Design with LabVIEW

Embedded systems play vital role in modern applications [1]. They can be found in autos, washing machines, electrical appliances and even in toys. FPGAs are the most recent computing technology that is used in embedded systems. There is an increasing demand on FPGA based embedded systems, in particular, for applications that require rapid time responses. Engineering education curricula needs to respond to the increasing industrial demand of using FPGAs by introducing new syllabus for teaching and learning this subject. This paper describes the development of new course material for teaching FPGA-based embedded systems design by using ‘G’ Programming Language of LabVIEW. A general overview of FPGA role in engineering education is provided. A survey of available Hardware Programming Languages for FPGAs is presented. A survey about LabVIEW utilization in engineering education is investigated; this is followed by a motivation section of why to use LabVIEW graphical programming in teaching and its capabilities. Then, a section of choosing a suitable kit for the course is laid down. Later, constructivist closed-loop model the FPGA course has been proposed in accordance with [2- 4; 80,86,89,92]. The paper is proposing a pedagogical framework for FPGA teaching; pedagogical evaluation will be conducted in future studies. The complete study has been done at the Faculty of Electrical and Electronic Engineering, Aleppo University