The theory of multidimensional persistence was introduced in a paper by G. Carlsson and A. Zomorodian as an extension to persistent homology. The central object in multidimensional persistence is the persistence module, which represents the homology of a multi filtered space. In this thesis, a novel algorithm for computing the persistence module is described in the case where the homology is computed with coefficients in a field. An algorithm for computing the feature counting invariant, introduced by Chachólski et al., is investigated. It is shown that its computation is in general NP-hard, but some special cases for which it can be computed efficiently are presented. In addition, a generalization of the barcode for persistent homology is defined and conditions for when it can be constructed uniquely are studied. Finally, a new topology is investigated, defined for fields of characteristic zero which, via the feature counting invariant, leads to a unique denoising of a tame and compact functor. / Teorin om multidimensionell persistens introduserades i en artikel av G. Carlsson och A. Zomorodian som en generalisering av persistent homologi. Det centrala objektet i multidimensionell persistens är persistensmodulen, som representerar homologin av ett multifilterat rum. I denna uppsats beskrivs en ny algoritm för beräkning av persistensmodulen i fallet där homologin beräknas med koefficienter i en kropp. En algoritm för beräkning av karaktäristik-räknings-invarianten, som introducerade av Chachólski et al., utforskas och det visar sig att dess beräkning i allmänhet är NP-svår. Några specialfall för vilka den kan beräknas effektivt presenteras. Vidare definieras en generalisering av stäckkoden för persistent homologi och kraven för när den kan konstrueras unikt studeras. Slutligen undersöks en ny topologi, definierad för kroppar av karaktäristik noll, som via karaktäristik-räknings-invarianten leder till en unik avbränning.

This paper examines treatment staff’s experience of threats and violence at The Swedish National Board of Institutional Care (SiS homes). The following study is based on eight different qualitative interviews with treatment staff at four different SiS homes around southern Sweden. The results show that the treatment staff experience threats and violence as a part of their everyday life at SiS homes and that it might negatively affect their work environment as well as their emotional well-being. The conclusion of the study highlights the importance of paying attention to and managing the problem of the normalized threats and violence in residential care facilities and the urgent need for increased support and further resources for the staff in order to create a safer working environment, mainly by limiting the youths usage of electronic communication resources i.e. Ipads. The study emphasizes urgent need for future research in order to adress the overwhelming issues of threats and violence in the workplace for the staff working in these high-risk environments.

Operation Gold (1953-56) was a collaborative covert operation between the American CIA and British SIS. The two major objectives: firstly, rebalance the state of affairs in covert activity, which the KGB had been dominating heading into the 1950s. Secondly, gain more detailed, valuable information on the state of Soviet forces throughout Europe and gain prior warning of possible information. The technological nature of the operation marks it as the beginning of a move away from traditional espionage. Understanding the narrative of Operation Gold establishes a firm foundation on which to address the development of covert activity into the modern day. Key elements of the story of the Berlin Tunnel serve to tie this lesser known operation to modern concerns of privacy, personal data, and covert involvement in international affairs. While unravelling the truest narrative of the planning and implementation of the operation, this thesis integrates substantial events, groups and people which shape the role of the Berlin Tunnel in understanding covert conflict. Further consideration is also given to how this operations legacy unfolded and the role of the media in understanding events in this separate sphere. Lessons about the covert sphere not only address a sub-narrative of 1950s Cold War but reach conclusions pertinent to the 21st century.

One of the major challenges in Big Data is the accurate and meaningful assessment of system performance. Unlike other systems, minor differences in efficiency can escalate to large differences in costs and power consumption. While there are several tools on the marketplace for measuring the performance of Big Data systems, few of them have been explored in-depth. This report investigated the interfacing, data generation and workload implementations of two Big Data benchmarking suites, BigDataBench and Hibench. The purpose of the study was to establish the capabilities of each tool with regards to interfacing, data generation and workload implementation. An exploratory and qualitative approach was used to gather information and analyze each benchmarking tool. Source code, documentation, and reports published by the developers were used as information sources. The results showed that BigDataBench and HiBench were designed similarly with regards to interfacing and data flow during the execution of a workload with the exception of streaming workloads. BigDataBench provided for more realistic data generation while the data generation for HiBench was easier to control. With regards to workload design, the workloads in BigDataBench were designed to be applicable to multiple frameworks while the workloads in HiBench were focused on the Hadoop family. In conclusion, neither of benchmarking suites was superior to the other. They were both designed for different purposes and should be applied on a case-by-case basis. / En av de stora utmaningarna i Big Data är den exakta och meningsfulla bedömningen av systemprestanda. Till skillnad från andra system kan mindre skillnader i effektivitet eskalera till stora skillnader i kostnader och strömförbrukning. Medan det finns flera verktyg på marknaden för att mäta prestanda för Big Data-system, har få av dem undersökts djupgående. I denna rapport undersöktes gränssnittet, datagenereringen och arbetsbelastningen av två Big Data benchmarking-sviter, BigDataBench och HiBench. Syftet med studien var att fastställa varje verktygs kapacitet med hänsyn till de givna kriterierna. Ett utforskande och kvalitativt tillvägagångssätt användes för att samla information och analysera varje benchmarking verktyg. Källkod, dokumentation och rapporter som hade skrivits och publicerats av utvecklarna användes som informationskällor. Resultaten visade att BigDataBench och HiBench utformades på samma sätt med avseende på gränssnitt och dataflöde under utförandet av en arbetsbelastning med undantag för strömmande arbetsbelastningar. BigDataBench tillhandahöll mer realistisk datagenerering medan datagenerering för HiBench var lättare att styra. När det gäller arbetsbelastningsdesign var arbetsbelastningen i BigDataBench utformad för att kunna tillämpas på flera ramar, medan arbetsbelastningen i HiBench var inriktad på Hadoop-familjen. Sammanfattningsvis var ingen av benchmarkingssuperna överlägsen den andra. De var båda utformade för olika ändamål och bör tillämpas från fall till fall.

No description available.

The aim of this thesis is to investigate the self-proclaimed performance of the National Board of Institutional Care, and its specific youth care homes in Sweden (SiS), concerning SiS work with institutionalised children and youth in relation to law of The Care of Young Persons Act (LVU). Special focus is also given to how the SiS self-assessment contrasts with the accounts given by institutionalised youths. We have investigated SiS claims present on their website since it provides ample documentation, information and deeds, and investigated reports by youth in the media, research and news outlets. We have elected to code all collected data and have thus identified key recurring themes present in youth and SiS reports.We have then regarded these findings with respect to our theories that are presented in the results and analysis section along with previous research. In this section we maintain that the description provided by youths at SiS is problematic and often shows a lack of care giving instances or staff that master the tools required to meet the youth in a constructive manner. In the discussion we once again maintain our theories and methodological approach that is based on Discourse analytical grounds that maintain the importance of language and the messages signified through actions.

Due to the unpredictability of the stock market,forecasting stock prices is a challenging task. In this project,we will investigate the performance of the machine learningalgorithm LSTM for stock market prediction. The algorithmwill be based only on historical numerical data and technicalindicators for IBM and FORD. Furthermore, the denoising anddimension reduction algorithm, PCA, is applied to the stockdata, to examine if the performance of forecasting the stockprice is greater than the initial model. A second method, transferlearning, is applied by training the model on the IBM datasetand then applying it on the FORD dataset, and vice versa, toevaluate if the results will improve. The results show that whenthe PCA algorithm is applied to the dataset separately, and incombination with transfer learning, the performance is greater incomparison to the initial model. Moreover, the transfer learningmodel is inconsistent as the performance is worse for FORD inrespect to the initial model, but better for IBM. Thus, concerningthe results when forecasting stock prices using related tools, it issuggested to use trial and error to identify which of the modelsthat performs the optimally. / Att förutse aktiekurser är en utmanande uppgift. Detta beror på aktiemarknadens oförutsägbarhet. Därför kommer vi i detta projekt att undersöka prestandan för maskininlärnings algoritmen LSTMs prognosförmåga för aktie priser. Algoritmen baseras endast på historisk numerisk data och tekniska indikatorer for företagen IBM och FORD. Vidare tillämpas brus minskande och dimension reducerande algorithmen, PCA, på aktiedata för att undersöka om prestandan för att förutse aktie priser är bättre än den ursprungliga modellen. En andra metod, transfer learning, tillämpas genom att träna modellen på IBM data och sedan använda den på FORD data, och vice versa, för att utvärdera om resultaten kommer att förbättras. Resultaten visar, när PCA-algoritmen tillämpas på aktiedata separat, och i kombination med transfer learning är prestandan bättre jämfört med bas modellen. Vidare kan vi inte dra slutsatser om transfer learning då prestandan är sämre för FORD med avseende på bas modellen, men bättre för IBM. I hänsyn till resultaten så föreslås det att man tillämpar modellerna för att identifiera vilken som är mest optimal när man arbetar i ett relaterat ämnesområde. / Kandidatexjobb i elektroteknik 2020, KTH, Stockholm

Sistemas diferenciais quadráticos planares estão presentes em muitas áreas da matemática aplicada. Embora mais de mil artigos tenham sido publicados sobre os sistemas quadráticos ainda resta muito a se conhecer sobre esses sistemas. Problemas clássicos, e em particular o XVI problema de Hilbert, estão ainda em aberto para essa família. Um dos objetivos dos pesquisadores contemporâneos é obter a classificação topológica completa dos sistemas quadráticos. Devido ao grande número de parâmetros (essa família possui doze parâmetros e, aplicando transformações afins e reescala do tempo, reduzimos esse número a cinco, sendo ainda um número grande para se trabalhar) usualmente subclasses são consideradas nas investigações realizadas. Quando características específicas são levadas em consideração, o número de parâmetros é reduzido e o estudo se torna possível. Nesta tese estudamos principalmente duas subfamílias de sistemas quadráticos: a primeira possuindo um nó triplo semielemental e a segunda possuindo uma selanó semi elemental finita e uma selanó semielemental infinita formada pela colisão de uma sela infinita com um nó infinito. Os diagramas de bifurcação para ambas as famílias são tridimensionais. A família tendo um nó triplo gera 28 retratos de fase topologicamente distintos, enquanto o fecho da família tendo as selasnós dentro do espaço de bifurcação de sua forma normal gera 417. Polinômios invariantes são usados para construir os conjuntos de bifurcação e os retratos de fase topologicamente distintos são representados no disco de Poincaré. Os conjuntos de bifurcação são a união de superfícies algébricas e superfícies cuja presença foi detectada numericamente. Ainda nesta tese, apresentamos todos os retratos de fase de um sistema diferencial conhecido como modelo do tipo SIS (sistema suscetívelinfectadosuscetível, muito comum na matemática aplicada) e a classificação dos sistemas quadráticos possuindo hipérboles invariantes. Ambos sistemas foram investigados usando de polinômios invariantes afins. / Planar quadratic differential systems occur in many areas of applied mathematics. Although more than one thousand papers have been written on these systems, a complete understanding of this family is still missing. Classical problems, and in particular Hilberts 16th problem, are still open for this family. One of the goals of recent researchers is the topological classification of quadratic systems. As this attempt is not possible in the whole class due to the large number of parameters (twelve, but, after affine transformations and time rescaling, we arrive at families with five parameters, which is still a large number), many subclasses are considered and studied. Specific characteristics are taken into account and this implies a decrease in the number of parameters, which makes possible the study. In this thesis we mainly study two subfamilies of quadratic systems: the first one possessing a finite semielemental triple node and the second one possessing a finite semielemental saddlenode and an infinite semielemental saddlenode formed by the collision of an infinite saddle with an infinite node. The bifurcation diagram for both families are tridimensional. The family having the triple node yields 28 topologically distinct phase portraits, whereas the closure of the family having the saddlenodes within the bifurcation space of its normal form yields 417. Invariant polynomials are used to construct the bifurcation sets and the phase portraits are represented on the Poincaré disk. The bifurcation sets are the union of algebraic surfaces and surfaces whose presence was detected numerically. Moreover, we also present the analysis of a differential system known as SIS model (this kind of systems are easily found in applied mathematics) and the complete classification of quadratic systems possessing invariant hyperbolas.

Sistemas diferenciais quadráticos planares estão presentes em muitas áreas da matemática aplicada. Embora mais de mil artigos tenham sido publicados sobre os sistemas quadráticos ainda resta muito a se conhecer sobre esses sistemas. Problemas clássicos, e em particular o XVI problema de Hilbert, estão ainda em aberto para essa família. Um dos objetivos dos pesquisadores contemporâneos é obter a classificação topológica completa dos sistemas quadráticos. Devido ao grande número de parâmetros (essa família possui doze parâmetros e, aplicando transformações afins e reescala do tempo, reduzimos esse número a cinco, sendo ainda um número grande para se trabalhar) usualmente subclasses são consideradas nas investigações realizadas. Quando características específicas são levadas em consideração, o número de parâmetros é reduzido e o estudo se torna possível. Nesta tese estudamos principalmente duas subfamílias de sistemas quadráticos: a primeira possuindo um nó triplo semielemental e a segunda possuindo uma selanó semi elemental finita e uma selanó semielemental infinita formada pela colisão de uma sela infinita com um nó infinito. Os diagramas de bifurcação para ambas as famílias são tridimensionais. A família tendo um nó triplo gera 28 retratos de fase topologicamente distintos, enquanto o fecho da família tendo as selasnós dentro do espaço de bifurcação de sua forma normal gera 417. Polinômios invariantes são usados para construir os conjuntos de bifurcação e os retratos de fase topologicamente distintos são representados no disco de Poincaré. Os conjuntos de bifurcação são a união de superfícies algébricas e superfícies cuja presença foi detectada numericamente. Ainda nesta tese, apresentamos todos os retratos de fase de um sistema diferencial conhecido como modelo do tipo SIS (sistema suscetívelinfectadosuscetível, muito comum na matemática aplicada) e a classificação dos sistemas quadráticos possuindo hipérboles invariantes. Ambos sistemas foram investigados usando de polinômios invariantes afins. / Planar quadratic differential systems occur in many areas of applied mathematics. Although more than one thousand papers have been written on these systems, a complete understanding of this family is still missing. Classical problems, and in particular Hilberts 16th problem, are still open for this family. One of the goals of recent researchers is the topological classification of quadratic systems. As this attempt is not possible in the whole class due to the large number of parameters (twelve, but, after affine transformations and time rescaling, we arrive at families with five parameters, which is still a large number), many subclasses are considered and studied. Specific characteristics are taken into account and this implies a decrease in the number of parameters, which makes possible the study. In this thesis we mainly study two subfamilies of quadratic systems: the first one possessing a finite semielemental triple node and the second one possessing a finite semielemental saddlenode and an infinite semielemental saddlenode formed by the collision of an infinite saddle with an infinite node. The bifurcation diagram for both families are tridimensional. The family having the triple node yields 28 topologically distinct phase portraits, whereas the closure of the family having the saddlenodes within the bifurcation space of its normal form yields 417. Invariant polynomials are used to construct the bifurcation sets and the phase portraits are represented on the Poincaré disk. The bifurcation sets are the union of algebraic surfaces and surfaces whose presence was detected numerically. Moreover, we also present the analysis of a differential system known as SIS model (this kind of systems are easily found in applied mathematics) and the complete classification of quadratic systems possessing invariant hyperbolas.

Pour préparer les futures missions sur satellites en radioastronomie, le CNES est responsable d'un projet de ballon stratosphérique appelé PRONAOS-SMH pour lequel notre laboratoire doit construire le récepteur à 380 GHz. Ce projet est décrit dans l'introduction. Dans le premier chapitre, j'expose les bases de la supraconductivité, de l'effet Josephson et du fonctionnement du mélangeur SIS. Le chapitre II développe la technologie utilisée pour la fabrication des jonctions SIS: les principes de l'évaporation, de la pulvérisation, de la gravure et de la photolithographie y sont expliqués. Le troisième chapitre est plus particulièrement consacré à la description et à l'optimisation du procédé de fabrication des jonctions en Nb/AI-A1Ox/Nb. Des jonctions fiables de petite dimension (1 micron carré) et de forte densité de courant sont obtenues. Les études nécessaires pour parvenir à ce résultat sont détaillées. L'intégration de ces jonctions dans des récepteurs millimétriques et submillimétriques est décrite dans le chapitre IV. Les premiers résultats obtenus dans le récepteur à 380 GHz sont prometteurs : une température de bruit de 310 K DSB pour le récepteur dans son ensemble a été mesurée à 374 GHz.