38 research outputs found

    Exploring new applications for photophysically encoded microcarriers

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    The first goal of this thesis was to investigate the potential of two cationic polysaccharides (PQ-4 and PQ-10) for DNA delivery. We have shown that, compared to PEI based polyplexes, they were less efficient in transfecting cells. However, as they had very low toxicity, further tailoring of the nature and extent of cationic side chains on cationic hydroxyethylcellulose may be a promising avenue to further enhance their DNA delivery properties. As a second goal we investigated the applications of digitally encoded microcarriers for cell based assays. We succeeded to show that encoded microcarriers were suitable to grow cells on. Neither the coating at the surface of the beads (which facilitates the growth of the cells), nor the cells themselves hampered the decoding of the beads, even when the cells covering the microcarriers exhibited green or red fluorescence due to the expression of GFP and RFP respectively. We were able (a) to immobilize DNA, siRNA or adenoviral particles on the surfaces of the encoded microcarriers by the use of polyelectrolytes and, subsequently, (b) to grow cells on top of the nucleic acids/adenoviral particles. The DNA and siRNA immobilized on the surface of the microcarrier were not able to transfect cells. However, we showed that the cells growing on the polyelectrolyte layer could indeed become transduced with adenoviral particles hosted by the polyelectrolyte layer. In conclusion, a proof of principal to use photophysically encoded microcarriers as transfected microarray has been shown. As a third goal we investigated the use of digitally encoded microcarriers as tool to combat counterfeiting of tablets. We showed that the codes in the Memobeads in tables produced by granulation did not deform during tabletting and that the code in the beads remained readable. We also found evidence that, after oral intake, the encoded microparticles are highly unlikely toxic to humans

    Reflective-Physically Unclonable Function based System for Anti-Counterfeiting

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    Physically unclonable functions (PUF) are physical security mechanisms, which utilize inherent randomness in processes used to instantiate physical objects. In this dissertation, an extensive overview of the state of the art in implementations, accompanying definitions and their analysis is provided. The concept of the reflective-PUF is presented as a product security solution. The viability of the concept, its evaluation and the requirements of such a system is explored

    Transparent, trustworthy and privacy-preserving supply chains

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    Over the years, supply chains have evolved from a few regional traders to globally complex chains of trade. Consequently, supply chain management systems have become heavily dependent on digitization for the purpose of data storage and traceability of goods. However, these traceability systems suffer from issues such as scattering of information across multiple silos and susceptibility of erroneous or modified data and thus are often unable to provide reliable information about a product. Due to propriety reasons, often end-to-end traceability is not available to the general consumer. The second issue is ensuring the credibility of the collated information about a product. The digital data may not be the true representation of the physical events which raises the issues of trusting the available information. If the source of digital data is not trustworthy, the provenance or traceability of a product becomes questionable. The third issue in supply chain management is a trade-off between the provenance information and protection of this data. The information is often associated with the identity of the contributing entity to ensure trust. However, the identity association makes it difficult to protect trade secrets such as shipments, pricing, and trade frequency of traders while simultaneously ensuring the provenance/traceability to the consumers. Our work aims to address above mentioned challenges related to traceability, trustworthiness and privacy. To support traceability and provenance, a consortium blockchain based framework, ProductChain, is proposed which provides an immutable audit trail of the supply chain events pertaining to the product and its origin. The framework also presents a sharded network model to meet the scalability needs of complex supply chains. Simulation results for our Proof of Concept (PoC) implementation show that query time for retrieving end-to-end traceability is of the order of a few milliseconds even when the information is collated from multiple regional blockchains. Next, to ensure the credibility of data from the supply chain entities, it is important to have an accountability mechanism which can penalise or reward the entities for their dishonest or honest contributions, respectively. We propose the TrustChain framework, which calculates a trust score for data contributing entities to the blockchain using multiple observations. These observations include feedback from interactions among supply chain entities, inputs from third party regulators and readings from IoT sensors. The integrated reputation system with blockchain, dynamically assigns trust and reputation scores to commodities and traders using smart contracts. A PoC implementation over Hyperledger Fabric shows that TrustChain incurs minimal overheads over a baseline. For protecting trade secrets while simultaneously ensuring traceability, PrivChain is proposed. PrivChain's framework allows traders to share computation or proofs in support of provenance and traceability claims rather than sharing the data itself. The framework also proposes an integrated incentive mechanism for traders providing such proofs. A PoC implementation on Hyperledger Fabric reveals a minimal overhead of using PrivChain as the data related computations are carried off-chain. Finally, we propose TradeChain which addresses the issue of preserving the privacy of identity related information with the blockchain data and gives greater access control to the data owners, i.e. traders. This framework decouples the identities of traders by managing two ledgers: one for managing decentralised identities and another for recording supply chain events. The information from both ledgers is then collated using access tokens provided by the data owners. In this way, they can dynamically control access to the blockchain data at a granular level. A PoC implementation is developed both on Hyperledger Indy and Fabric and we demonstrate minimal overheads for the different components of TradeChain

    Optical scattering for security applications

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    Laser Surface Authentication (LSA) has emerged in recent years as a potentially disruptive tracking and authentication technology. A strong need for such a solution in a variety of industries drove the implementation of the technology faster than the scientific understanding could keep up. The drive to miniaturise and simplify, the need to be robust against real-world problems like damage and misuse, and not least, intellectual curiosity, make it clear that a firmer scientific footing is important as the technology matures. Existing scattering and biometric work are reviewed, and LSA is introduced as a technology. The results of field-work highlight the restrictions which are encountered when the technology is applied. Analysis of the datasets collected in the trial provide, first, an indication of the performance of LSA under real-world conditions and, second, insight into the potential shortcomings of the technique. Using the particulars of the current sensor’s geometry, the LSA signal is characterised. Measurements are made of the decorrelation of the signature with linear and rotational offsets, and it is concluded that while surface microstructure has a strong impact on the rate of decorrelation, this dependency is not driven by the surface’s feature size. A new series of experiments examine that same decorrelation for interference effects with different illumination conditions, and conclude that laser speckle is not an adequate explanation for the phenomenon. The results of this experimental work inform a mathematical description of LSA based on a combination of existing bi-static scattering models used in physics and ray-tracing, which is implemented numerically. The results of the model are found to be a good fit to experimental work, and new predictions are made about LSA

    Applications of Blockchain Technology in International Logistics - a Case Study

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    This work gives some insights about the beneficial impact that blockchain technology could have on the trust paradigm of modern supply chains, especially in the international logistics sector. The first two parts cover a non-technical but detailed description of how the Bitcoin protocol works and a deep dive on the possible applications of blockchain technology in the logistics industry. The third part is reserved for the Case Study, theorized with the help of Luxottica

    Tematski zbornik radova međunarodnog značaja. Tom 3 / Međunarodni naučni skup “Dani Arčibalda Rajsa”, Beograd, 10-11. mart 2016.

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    In front of you is the Thematic Collection of Papers presented at the International Scientific Conference “Archibald Reiss Days”, which was organized by the Academy of Criminalistic and Police Studies in Belgrade, in co-operation with the Ministry of Interior and the Ministry of Education, Science and Technological Development of the Republic of Serbia, National Police University of China, Lviv State University of Internal Affairs, Volgograd Academy of the Russian Internal Affairs Ministry, Faculty of Security in Skopje, Faculty of Criminal Justice and Security in Ljubljana, Police Academy “Alexandru Ioan Cuza“ in Bucharest, Academy of Police Force in Bratislava and Police College in Banjaluka, and held at the Academy of Criminalistic and Police Studies, on 10 and 11 March 2016. The International Scientific Conference “Archibald Reiss Days” is organized for the sixth time in a row, in memory of the founder and director of the first modern higher police school in Serbia, Rodolphe Archibald Reiss, PhD, after whom the Conference was named. The Thematic Collection of Papers contains 165 papers written by eminent scholars in the field of law, security, criminalistics, police studies, forensics, informatics, as well as by members of national security system participating in education of the police, army and other security services from Belarus, Bosnia and Herzegovina, Bulgaria, China, Croatia, Greece, Hungary, Macedonia, Montenegro, Romania, Russian Federation, Serbia, Slovakia, Slovenia, Spain, Switzerland, Turkey, Ukraine and United Kingdom. Each paper has been double-blind peer reviewed by two reviewers, international experts competent for the field to which the paper is related, and the Thematic Conference Proceedings in whole has been reviewed by five competent international reviewers. The papers published in the Thematic Collection of Papers contain the overview of contemporary trends in the development of police education system, development of the police and contemporary security, criminalistic and forensic concepts. Furthermore, they provide us with the analysis of the rule of law activities in crime suppression, situation and trends in the above-mentioned fields, as well as suggestions on how to systematically deal with these issues. The Collection of Papers represents a significant contribution to the existing fund of scientific and expert knowledge in the field of criminalistic, security, penal and legal theory and practice. Publication of this Collection contributes to improving of mutual cooperation betw

    Verified, Tracked, and Visible: A History of the Configuration of the Internet User

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    The figure of the user is often overlooked in Internet histories, which frequently focus on larger treatments of infrastructure, governance, or major contributions of specific individuals. This thesis constructs a philosophical and ideological history of the Internet user and examines how that figure has changed though the evolution of the Internet. Beginning with the Web 2.0 paradigm in the early 2000s, a growing state and corporate interest in the Internet produced substantial changes to the structure and logic of the Internet that saw the user being placed increasingly at the periphery of online space as the object of state surveillance or behavioral tracking. The three case studies in this thesis investigate the combination of technological constraints and discursive strategies which have aided in shaping the contemporary user from active architect of the Internet itself to passive, ideal consumer of predetermined online experiences

    Blockchain readiness for countries towards 2030- the barriers and benefits of adopting blockchain technology

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    This study investigates the factors of blockchain that will promote sustainable business towards the year 2030. The study provides an outlook to areas where business might be vulnerable in the event of blockchain implementation. The findings of this study were identified by means of an online questionnaire that targeted specialists in the arena of blockchain and business management. By a thematic analysis, the outcome of the study guides, precautions, and prepares organisations for what may come in the future of blockchain

    Blockchain readiness for countries towards 2030- the barriers and benefits of adopting blockchain technology

    Get PDF
    This study investigates the factors of blockchain that will promote sustainable business towards the year 2030. The study provides an outlook to areas where business might be vulnerable in the event of blockchain implementation. The findings of this study were identified by means of an online questionnaire that targeted specialists in the arena of blockchain and business management. By a thematic analysis, the outcome of the study guides, precautions, and prepares organisations for what may come in the future of blockchain
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