23 research outputs found

    Implementation of lightweight machine learning-based intrusion detection system on IoT devices of smart homes

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    Smart home devices, also known as IoT devices, provide significant convenience; however, they also present opportunities for attackers to jeopardize homeowners’ security and privacy. Securing these IoT devices is a formidable challenge because of their limited computational resources. Machine learning-based intrusion detection systems (IDSs) have been implemented on the edge and the cloud; however, IDSs have not been embedded in IoT devices. To address this, we propose a novel machine learning-based two-layered IDS for smart home IoT devices, enhancing accuracy and computational efficiency. The first layer of the proposed IDS is deployed on a microcontroller-based smart thermostat, which uploads the data to a website hosted on a cloud server. The second layer of the IDS is deployed on the cloud side for classification of attacks. The proposed IDS can detect the threats with an accuracy of 99.50% at cloud level (multiclassification). For real-time testing, we implemented the Raspberry Pi 4-based adversary to generate a dataset for man-in-the-middle (MITM) and denial of service (DoS) attacks on smart thermostats. The results show that the XGBoost-based IDS detects MITM and DoS attacks in 3.51 ms on a smart thermostat with an accuracy of 97.59%.</p

    The snomipede : a parallel platform for scanning near-field photolithography.

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    Using scanning near-field lithography (SNP), it is possible to pattern molecules at surfaces with a resolution as good as 9 nm [M. Montague, R. E. Ducker, K. S. L. Chong, R. J. Manning, F. J. M. Rutten, M. C. Davies and G. J. Leggett, Langmuir 23 (13), 7328–7337 (2007)]. However, in common with other scanning probe techniques, SNP has previously been considered a serial process, hindering its use in many applications. IBM’s “Millipede” addresses this problem by utilizing an array of local probes operating in parallel. Here, we describe the construction of two instruments (Snomipedes) that integrate near-field optical methods into the parallel probe paradigm and promise the integration of top–down and bottom–up fabrication methods over macroscopic areas. Both are capable of performing near-field lithography with 16 probes in parallel spanning approximately 2 mm. The instruments can work in both ambient and liquid environments, key to many applications in nanobiology. In both, separate control of writing is possible for each probe. We demonstrate the deprotection of self-assembled monolayers of alkylsilanes with photocleavable protecting groups and subsequent growth of nanostructured polymer brushes from these nanopatterned surfaces by atom-transfer radical polymerization

    Photocatalytic Nanolithography of Self-Assembled Monolayers and Proteins

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    Self-assembled monolayers of alkylthiolates on gold and alkylsilanes on silicon dioxide have been patterned photocatalytically on sub-100 nm length-scales using both apertured near-field and apertureless methods. Apertured lithography was carried out by means of an argon ion laser (364 nm) coupled to cantilever-type near-field probes with a thin film of titania deposited over the aperture. Apertureless lithography was carried out with a helium–cadmium laser (325 nm) to excite titanium-coated, contact-mode atomic force microscope (AFM) probes. This latter approach is readily implementable on any commercial AFM system. Photodegradation occurred in both cases through the localized photocatalytic degradation of the monolayer. For alkanethiols, degradation of one thiol exposed the bare substrate, enabling refunctionalization of the bare gold by a second, contrasting thiol. For alkylsilanes, degradation of the adsorbate molecule provided a facile means for protein patterning. Lines were written in a protein-resistant film formed by the adsorption of oligo(ethylene glycol)-functionalized trichlorosilanes on glass, leading to the formation of sub-100 nm adhesive, aldehyde-functionalized regions. These were derivatized with aminobutylnitrilotriacetic acid, and complexed with Ni2+, enabling the binding of histidine-labeled green fluorescent protein, which yielded bright fluorescence from 70-nm-wide lines that could be imaged clearly in a confocal microscope

    Penetration Testing of Android-based Smartphones

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    The purpose of this work has been to perform a security analysis of Android-based Smartphones. Smartphone usage and adaptation are increasing day by day with a variety of applications. These applications can be very critical in nature such as mobile banking, and mobile payment systems and users are often unknowing about the security risks involved in such applications. Android, an open source operating system, is rapidly increasing in the Smartphone industry. It has already beaten the most popular mobile operating systems, like RIM, iOS, Windows Mobile and even Symbian, which ruled the mobile market for more than a decade. In this thesis, we have analysed the architecture of the Android operating system and tested its security through penetration testing. We have picked the most popular and recommended tools to test the security in the TCP/IP suite and different attacks have been performed on three different Android versions. The thesis also contains a discussion about our findings, how secure the Android system is and how much trust can be placed on it while using it

    Rheological issues in carbon-based inks for additive manufacturing

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    As the industry and commercial market move towards the optimization of printing and additive manufacturing, it becomes important to understand how to obtain the most from the materials while maintaining the ability to print complex geometries effectively. Combining such a manufacturing method with advanced carbon materials, such as Graphene, Carbon Nanotubes, and Carbon fibers, with their mechanical and conductive properties, delivers a cutting-edge combination of low-cost conductive products. Through the process of printing the effectiveness of these properties decreases. Thorough optimization is required to determine the idealized ink functional and flow properties to ensure maximum printability and functionalities offered by carbon nanoforms. The optimization of these properties then is limited by the printability. By determining the physical properties of printability and flow properties of the inks, calculated compromises can be made for the ink design. In this review we have discussed the connection between the rheology of carbon-based inks and the methodologies for maintaining the maximum pristine carbon material properties

    Development of comprehensive coursework of quality management in universities pertinent to the construction industry: a case of Pakistan

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    PurposeThe purpose of this research is to determine a comprehensive coursework for teaching quality management in the universities of developing countries i.e. Pakistan pertinent to the construction industry. Additionally, a framework was also developed based on the results.Design/methodology/approachFactors and course contents of quality management are extracted through a content analysis of the published literature. Further, a questionnaire survey is conducted involving 150 professionals to assess the requirements of the industry and academic professionals of the construction industry for effective quality management. Finally, for getting a more objective perspective, using quality function deployment (QFD) matrix a framework is developed.FindingsThe results show the level of importance of each design requirement. We can identify the design requirements through which we can fulfill the needs and demands of the stakeholders. Contents like benchmarking, supply chain management, six sigma and other data analysis methods, costing and auditing of quality, customer satisfaction analysis, TQM: theory and practices and ISO certification processes and procedures should be included in any course program related to quality management pertinent to the construction industry. Along with these contents, workshops and seminars must be arranged to address the user requirement for increased leadership and communication skills.Originality/valueThere is a lack of literature available on course content for quality management in the universities for the construction sector, therefore, a huge scope of future research in the field of quality management in the construction industry needs to be investigated. This research highlights the most significant quality management factors and course contents as per the requirement of industry professionals. Therefore, this study adds to the existing body of knowledge by developing a robust framework that will help decision-makers and top management to develop constructive quality management course work at university level that will help in producing qualified and trained quality professionals to the construction industry.</jats:sec

    Protein micro- and nanopatterning using aminosilanes with protein-resistant photolabile protecting groups

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    An approach to the integration of nanolithography with synthetic chemical methodology is described, in which near-field optical techniques are used to selectively deprotect films formed by the adsorption of aminosilanes protected by modified 2-nitrophenylethoxycarbonyl (NPEOC) groups. The NPEOC groups are functionalized at the m- or p-position with either a tetraethyleneglycol or a heptaethylene glycol adduct. We describe the synthesis of these bioresistant aminosilanes and the characterization of the resulting photoreactive films. Photodeprotection by exposure to UV light (λ = 325 nm) yielded the amine with high efficiency, at a similar rate for all four adsorbates, and was complete after an exposure of 2.24 J cm−2. Following photodeprotection, derivatization by trifluoroacetic anhydride was carried out with high efficiency. Micropatterned samples, formed using a mask, were derivatized with aldehyde-functionalized polymer nanoparticles and, following derivatization with biotin, were used to form patterns of avidin-coated polymer particles. Fluorescence microscopy and atomic force microscopy data demonstrated that the intact protecting groups conferred excellent resistance to nonspecific adsorption. Nanometer-scale patterns were created using scanning near-field photolithography and were derivatized with biotin. Subsequent conjugation with avidin-functionalized polymer nanoparticles yielded clear fluorescence images that indicated dense attachment to the nanostructures and excellent protein resistance on the surrounding surface. These simple photocleavable protecting group strategies, combined with the use of near-field exposure, offer excellent prospects for the control of surface reactivity at nanometer resolution in biological systems and offer promise for integrating the top-down and bottom-up molecular fabrication paradigms

    Photocatalytic degradation of metronidazole (MNZ) antibiotic by CuO nanoparticles for environmental protection from pharmaceutical pollution

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    Metronidazole (MNZ) is one of the extensively consumed generic antibiotics, which, due to its high resistance to biological degradation, is considered a potent environmental contaminant. In this study, we use CuO nanoparticles (NPs) for photocatalytic degradation of MNZ. Photocatalytic NPs with a crystallinity of over 80% were synthesized using a facile co-precipitation method followed by calcination at a temperature of 500 °C for a duration of 1 hour. Nanoparticles were characterized thoroughly to investigate their opto-structural properties. We investigated the efficiency of photocatalytic degradation with the variation of MNZ concentration, NP loading and the pH of the MNZ solution. Experimental results revealed that the pH of the MNZ solution strongly controlled the photocatalytic degradation efficiency. As pH was increased from 7 to 11, the degradation rate was enhanced remarkably. Degradation efficiency was also found to be strongly dependent on the concentration of both MNZ solution and CuO NPs.</p

    Tuning anatase to rutile ratio in nanocrystalline titania enriched from sustainable beach-sand from Cox’s Bazar, Bangladesh

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    A sustainable source of titania (TiO2) is important in applications of photovoltaic devices, photocatalysts, sensors etc. Beach sand from Cox’s Bazar, Bangladesh can be an excellent sustainable source of this titania as almost a quarter of it contains titania in the form of rutile and ilmenite. This study demonstrates the success of a sulfuric acid-based hydrometallurgical process in enriching titania in Cox’s Bazar Beach Sand. The route produces precursors that can be conveniently calcined into nanocrystalline phase-pure anatase or anatase/rutile composites. We used both bulk and surface characterization to determine phase purity, crystallite size as well as surface chemistry and morphology of the resulting anatase and rutile/anatase mixture. The proportion of anatase/rutile can be tuned by varying digestion times. This hydrometallurgical route can potentially lead to the scalable production of precursors used in producing high-performance nanocrystalline titania from a sustainable source of beach sand from Cox’s Bazar of Bangladesh. </p
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