Выпускная квалификационная работа 56 страниц, 19 рисунков, 11 источников, 8 приложений. Цель работы – разработка клиентской части веб-приложения «Мониторинг IT-конференций». В процессе работы был проведён анализ популярных фреймворков для веб-разработки, настроена интеграция с серверами CDN на базе сервиса Surge, создан Docker-образ с веб-приложением, настроена интеграция с GitHub Actions для CI/CD, настроен клиентский и серверный мониторинги на базе Sentry. В результате ВКР разработана клиентская часть на базе фреймворка Next.js для веб-приложения «Мониторинг IT-конференций». / Final qualification work 56 pages, 19 figures, 11 sources, 8 appendices. The purpose of the work is to develop the client part of the web application "Monitoring of IT conferences". In the process, we analyzed popular frameworks for web development, configured integration with CDN servers based on the Surge service, created a Docker image with a web application, configured integration with GitHub Actions for CI/CD, configured client and server monitoring based on Sentry. As a result of the final qualifying work, the client part was developed on the basis of the Next framework.js for the IT Conference Monitoring web application.

Laminated glass (LG) consists of two or more glass layers bonded by an elasto-polymeric layer, the most commonly used being PVB (Polyvinyl Butyral). LG has improved safety properties compared with single layer glass because the interlayer prevents large sharp pieces from spreading when the glass is broken by impact. Even if one of the layers breaks, the other layer(s) still contribute in carrying the load. Through proper understanding of the interaction between the interlayer and the glass LG could be used in engineering as a load bearing material to a larger extent. This study aims at gaining a deeper knowledge of the behaviour of laminated glass by experimental investigations and by numerical model simulation. To pursue the proposed study, three point bending test with simple support conditions were performed for single layer glass and laminated glass units with three different types of interlayer materials. Corresponding finite element numerical models were created in the software ABAQUS to fit the model with experiment to obtain the bending stiffness and shear stiffness of the interlayer material. The PVB tested showed viscos-elastic material properties, whereas other two interlayer materials, Solutia DG 41 and Sentry Glass, showed linear elastic properties. PVB is the least stiff interlayer material among the three types. Solutia DG 41 and Sentry Glass have similar stiffness, about 13 to 15 times stiffer than the PVB. The behaviour of laminated glass lies in general between the two limits of a layered glass unit with no interaction and a monolithic unit of the same total thickness, depending on the stiffness of the interlayer material. Failure tests of the specimens were also carried out. The obtained strength of glass from four specimens is 80 MPa to 92 MPa with a variation of about 15%. The number of more performed experiments would have better outcome for strength of glass. The bending stiffness of the laminated glass as estimated with the numerical model fitted well with the experimental results with an error of about 2%. Hence the experimentally and numerically obtained results show a good correlation and are thought be possible to use in future larger scale modelling.

There are different ways to store and process large amount of data. Hadoop iswidely used, one of the most popular platforms to store huge amount of dataand process them in parallel. While storing sensitive data, security plays animportant role to keep it safe. Security was not that much considered whenHadoop was initially designed. The initial use of Hadoop was managing largeamount of public web data so confidentiality of the stored data was not anissue. Initially users and services in Hadoop were not authenticated; Hadoop isdesigned to run code on a distributed cluster of machines so without properauthentication anyone could submit code and it would be executed. Differentprojects have started to improve the security of Hadoop. Two of these projectsare called project Rhino and Project Sentry [1].Project Rhino implements splittable crypto codec to provide encryptionfor the data that is stored in Hadoop distributed file system. It also developsthe centralized authentication by implementing Hadoop single sign on whichprevents repeated authentication of the users accessing the same services manytimes. From the authorization point of view Project Rhino provides cell-basedauthorization for Hbase [2].Project Sentry provides fine-grained access control by supporting role-basedauthorization which different services can be bound to it to provide authorizationfor their users [3].It is possible to combine security enhancements which have been done inthe Project Rhino and Project Sentry to further improve the performance andprovide better mechanisms to secure Hadoop.In this thesis, the security of the system in Hadoop version 1 and Hadoopversion 2 is evaluated and different security enhancements are proposed, consideringsecurity improvements made by the two aforementioned projects, ProjectRhino and Project Sentry, in terms of encryption, authentication, and authorization.This thesis suggests some high-level security improvements on theCentralized authentication system (Hadoop Single Sign on) implementationmade by Project Rhino.

TEM and SHV β-lactamases are the most prevalent β-lactamases among Gram-negative bacteria. The introduction and widespread use of expanded-spectrum antibiotics, particularly third generation cephalosporins, has led to the evolution of bacterial strains expressing extended spectrum β-lactamases (ESBLs). ESBLs emerge by genetic point mutation from non-extended spectrum precursors. It was found that multiple β-lactamase families within single isolates complicate the process of detecting the resistance status of isolate using non-quantitative DNA diagnostic methods. Preliminary phenotypic characterisation of probable β-lactamase enzyme family types present in 100 isolates from the Asia-Pacific and South African locales showed that single isolates frequently contained multiple β-lactamase families. SHV, TEM, AMPC and CTX-M β-lactamase families were detected in these isolates using PCR detection methods. Ninety-eight percent of all isolates tested contained as least one β-lactamase gene, with up to four to β-lactamase gene families found to co-exist in single isolates. Kinetic PCR methods for interrogating the polymorphic sites at blaSHV codons 238 & 240 and blaTEM codons 164, 238, 240 as well as promoter polymorphism were developed. A high proportion of blaSHV 238 and 240 mutant alleles was found to correlate with cefotaxime, ceftazidime and aztreonam resistance levels. In an attempt to understand the molecular basis for the co-existence of multiple blaSHV alleles within single isolates, the blaSHV promoter region was cloned from one ESBL expressing isolate. Experimental results showed that blaSHV can exist downstream of two different promoters within a single isolate. Both promoters have previously been reported, and differ by the presence or absence of IS26, which results in a change in the transcription initiation site. The blaSHV gene copy numbers in cis with the different promoters were measured, and it was found that the copy number of the IS26::blaSHV promoter was positively correlated with resistance levels. Cloning and analysis of PCR products showed that different blaSHV variants existed in cis with promoters in individual isolates. However, mutant genes were more abundant downstream of the IS26 promoter. There were no ESBL+ isolates without this promoter. It was concluded that blaSHV in cis with the IS26 promoter is located on an amplifiable replicon, and the presence of the IS26 insertion may facilitate the acquisition of an ESBL+ phenotype. To further confirm the role of IS26 in resistance acquisition, ESBL negative isolates were subjected to serial passage in vitro evolution experiments and fluctuation assays. Results confirm that the insertion of the IS26 element upstream of blaSHV is positively correlated with the ability to exhibit an ESBL phenotype, when such isolates also contain the critical G238S substitution. It was also found that IS26 can catalyse the duplication and mobilisation of blaSHV within an isolate. Fluctuation experiments have shown that the frequency at which such genomic events occur resulting in ESBL phenotypes is extremely low and requires many generations of selection under sub-lethal conditions. A survey of a geographically diverse set of isolates has shown that IS26-blaSHV was found in all of the bacterial populations surveyed. However, it does not appear to be exclusively associated with SHV-mediated ESBL production.

Extended spectrum β-lactamases or ESBLs, which are derived from non-ESBL precursors by point mutation of β-lactamase genes (bla), are spreading rapidly all over the world and have caused considerable problems in the treatment of infections caused by bacteria which harbour them. The mechanism of this resistance is not fully understood and a better understanding of these mechanisms might significantly impact on choosing proper diagnostic and treatment strategies. Previous work on SHV β-lactamase gene, blaSHV, has shown that only Klebsiella pneumoniae strains which contain plasmid-borne blaSHV are able to mutate to phenotypically ESBL-positive strains and there was also evidence of an increase in blaSHV copy number. Therefore, it was hypothesised that although specific point mutation is essential for acquisition of ESBL activity, it is not yet enough, and blaSHV copy number amplification is also essential for an ESBL-positive phenotype, with homologous recombination being the likely mechanism of blaSHV copy number expansion. In this study, we investigated the mutation rate of non-ESBL expressing K. pneumoniae isolates to an ESBL-positive status by using the MSS-maximum likelihood method. Our data showed that blaSHV mutation rate of a non-ESBL expressing isolate is lower than the mutation rate of the other single base changes on the chromosome, even with a plasmid-borne blaSHV gene. On the other hand, mutation rate from a low MIC ESBL-positive (≤ 8 µg/mL for cefotaxime) to high MIC ESBL-positive (≥16 µg/mL for cefotaxime) is very high. This is because only gene copy number increase is needed which is probably mediated by homologous recombination that typically takes place at a much higher frequencies than point mutations. Using a subinhibitory concentration of novobiocin, as a homologous recombination inhibitor, revealed that this is the case.