Global warming is currently a major challenge faced by the world. Reduction of carbon emissions is of paramount importance in the context of global warming. There are widespread ongoing efforts to find satisfactory ways of surmounting this challenge. The basic objective of all such efforts can be summarized as conception and formation of protocols to reduce the pace of global carbon levels. Countries and global companies are now engaged in understanding systematic ways of achieving well defined emission targets. In this dissertation, we explore the specific problem faced by a global industry or global company in allocating carbon emission reduction units to its different divisions and supply chain partners in achieving a required target of reductions in its carbon reduction program. The problem becomes a challenging one since the divisions and supply chain partners are often autonomous and could exhibit strategic behavior. Game theory and mechanism design provide a natural modeling tool for capturing the strategic dynamics involved in this problem. DSIC (Dominant Strategy Incentive Compatibility), AE (Allocative Efficiency), and SBB (Strict Budget Balance) are the key desirable properties for carbon reduction allocation mechanisms. But due to an impossibility result in mechanism design, DSIC, AE, and SBB can never be simultaneously achieved. Hence in this dissertation, we offer as contributions, two elegant solutions to this carbon emission reduction allocation problem. The first contribution is a mechanism which is DSIC and AE. We first propose a straightforward Vickrey-Clarke-Groves (VCG) mechanism based solution to the problem, leading to a DSIC and AE reverse auction protocol for allocating carbon reductions among the divisions. This solution, however, leads to a high level of budget imbalance. To reduce budget imbalance, we use redistribution mechanisms, without affecting the key properties of DSIC and AE. The Cavallo-Bailey redistribution mechanism, when applied to the above reverse auction protocol leads to reduced budget imbalance. To reduce the imbalance further, we propose an innovative forward auction protocol which achieves less imbalance when combined with the Cavallo-Bailey redistribution mechanism. The forward auction protocol also has the appealing feature of handsomely rewarding divisions that reduce emissions and levying appropriate penalties on divisions that do not participate in emission reductions. The second contribution is a DSIC and SBB mechanism. Even though the first mechanism tries to reduce the budget imbalance, there is always a surplus which cannot be distributed among divisions and is wasted. So, in this part, by slightly compromising on efficiency, we propose a mechanism which is DSIC and SBB. The SBB property guarantees that there is no need for any monetary support from an external agency for implementing the mechanism and there is no leakage of revenue.

Fraud is a common crime within the insurance industry, and insurance companies want to quickly identify fraudulent claimants as they often result in higher premiums for honest customers. Due to the digital transformation where the sheer volume and complexity of available data has grown, manual fraud detection is no longer suitable. This work aims to automate the detection of fraudulent claimants and gain practical insights into fraudulent behavior using unsupervised anomaly detection, which, compared to supervised methods, allows for a more cost-efficient and practical application in the insurance industry. To obtain interpretable results and benefit from the temporal dependencies in human behavior, we propose two variations of LSTM based autoencoders to classify sequences of insurance claims. Autoencoders can provide feature importances that give insight into the models' predictions, which is essential when models are put to practice. This approach relies on the assumption that outliers in the data are fraudulent. The models were trained and evaluated on a dataset we engineered using data from a Swedish insurance company, where the few labeled frauds that existed were solely used for validation and testing. Experimental results show state-of-the-art performance, and further evaluation shows that the combination of autoencoders and LSTMs are efficient but have similar performance to the employed baselines. This thesis provides an entry point for interested practitioners to learn key aspects of anomaly detection within fraud detection by thoroughly discussing the subject at hand and the details of our work. / <p>Gjordes digitalt via Zoom. </p>

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The aim of this doctoral dissertation is to assess the probable impact of ionizing radiation on the public health and the environment (including fauna and flora) in the vicinity of nuclear power engineering objects (in case of the Maišiagala near-surface radioactive waste repository – by evaluating the possible impact on the human health, while in case of the Ignalina NPP cooling basin, Lake Drūkšiai – by evaluating the possible impact on the freshwater ecosystem biota) by applying probabilistic methods as well as to determine whether this activity after assessment of its character and impact on the environment meets the standards valid in the Republic of Lithuania or in the European Union and is permissible at a selected site at present or in the future. In the work two main programs, RESRAD-OFFSITE and ERICA, using scattering of site-specific parameter values and probabilistic (correlation, regressive, sensitivity, etc.) analysis, have been applied. It has been determined that in the environment of the Maišiagala repository after installation of additional protective barriers the annual effective human exposure dose is significantly lower as compared to the limited dose and 95th percentile dose not exceed the exposure of 1 mSv per year regulated in the hygiene standards. The exposure dose rate of standardized organisms of Lake Drūkšiai, the Ignalina NPP cooler, freshwater ecosystem biota due to the INPP discharges and waterway radionuclide migration from a hypothetic... [to full text] / Šios daktaro disertacijos tikslas - įvertinti galimą jonizuojančiosios spinduliuotės poveikį visuomenės sveikatai ir aplinkai (tame tarpe gyvūnijai ir augalijai) branduolinės energetikos objektų aplinkoje (Maišiagalos radioaktyviųjų atliekų saugyklos atveju - vertinant galimą poveikį žmogui, ir IAE aušintuvo Drūkšių ežero atveju - vertinant galimą poveikį gėlavandenės ekosistemos biotai), taikant tikimybinius metodus; nustatyti, ar ši veikla, įvertinus jos pobūdi ir poveikį aplinkai, atitinka Lietuvos Respublikoje arba Europos Sąjungoje galiojančius standartus, yra leistina pasirinktoje vietoje dabartiniu laikotarpiu arba ateityje. Darbe buvo taikomos 2 pagrindinės programos: RESRAD-OFFSITE ir ERICA., naudojant vietines sąlygas atitinkančius parametrų verčių išbarstymą, taikant tikimybinę (koreliacinę, regresinę, jautrio ir kt.) analizę. Nustatyta, kad, įrengus papildomus apsauginius barjerus, Maišiagalos saugyklos aplinkoje metinė efektinė gyventojų apšvitos dozė yra ženkliai mažesnė lyginant su apribotosios dozės dydžiu, 95 procentilė nesiekia higienos normose patvirtintos 1mSv per metus ribinės dozės dydžio. Ignalinos AE aušintuvo Drūkšių ežero gėlavandenės ekosistemos biotos standartizuotųjų organizmų apšvitos dozės galia dėl IAE nuotekų ir radionuklidų sklaidos vandens keliu iš hipotetinio Stabatiškės radioaktyviųjų atliekų kapinyno rodo, kad apšvitos dozės galia dėl antropogeninės kilmės radionuklidų jonizuojančiosios spinduliuotės poveikio neviršija Europos Sąjungoje... [toliau žr. visą tekstą]

Šios daktaro disertacijos tikslas - įvertinti galimą jonizuojančiosios spinduliuotės poveikį visuomenės sveikatai ir aplinkai (tame tarpe gyvūnijai ir augalijai) branduolinės energetikos objektų aplinkoje (Maišiagalos radioaktyviųjų atliekų saugyklos atveju - vertinant galimą poveikį žmogui, ir IAE aušintuvo Drūkšių ežero atveju - vertinant galimą poveikį gėlavandenės ekosistemos biotai), taikant tikimybinius metodus; nustatyti, ar ši veikla, įvertinus jos pobūdi ir poveikį aplinkai, atitinka Lietuvos Respublikoje arba Europos Sąjungoje galiojančius standartus, yra leistina pasirinktoje vietoje dabartiniu laikotarpiu arba ateityje. Darbe buvo taikomos 2 pagrindinės programos: RESRAD-OFFSITE ir ERICA., naudojant vietines sąlygas atitinkančius parametrų verčių išbarstymą, taikant tikimybinę (koreliacinę, regresinę, jautrio ir kt.) analizę. Nustatyta, kad, įrengus papildomus apsauginius barjerus, Maišiagalos saugyklos aplinkoje metinė efektinė gyventojų apšvitos dozė yra ženkliai mažesnė lyginant su apribotosios dozės dydžiu, 95 procentilė nesiekia higienos normose patvirtintos 1mSv per metus ribinės dozės dydžio. Ignalinos AE aušintuvo Drūkšių ežero gėlavandenės ekosistemos biotos standartizuotųjų organizmų apšvitos dozės galia dėl IAE nuotekų ir radionuklidų sklaidos vandens keliu iš hipotetinio Stabatiškės radioaktyviųjų atliekų kapinyno rodo, kad apšvitos dozės galia dėl antropogeninės kilmės radionuklidų jonizuojančiosios spinduliuotės poveikio neviršija Europos Sąjungoje... [toliau žr. visą tekstą] / The aim of this doctoral dissertation is to assess the probable impact of ionizing radiation on the public health and the environment (including fauna and flora) in the vicinity of nuclear power engineering objects (in case of the Maišiagala near-surface radioactive waste repository – by evaluating the possible impact on the human health, while in case of the Ignalina NPP cooling basin, Lake Drūkšiai – by evaluating the possible impact on the freshwater ecosystem biota) by applying probabilistic methods as well as to determine whether this activity after assessment of its character and impact on the environment meets the standards valid in the Republic of Lithuania or in the European Union and is permissible at a selected site at present or in the future. In the work two main programs, RESRAD-OFFSITE and ERICA, using scattering of site-specific parameter values and probabilistic (correlation, regressive, sensitivity, etc.) analysis, have been applied. It has been determined that in the environment of the Maišiagala repository after installation of additional protective barriers the annual effective human exposure dose is significantly lower as compared to the limited dose and 95th percentile dose not exceed the exposure of 1 mSv per year regulated in the hygiene standards. The exposure dose rate of standardized organisms of Lake Drūkšiai, the Ignalina NPP cooler, freshwater ecosystem biota due to the INPP discharges and waterway radionuclide migration from a hypothetic... [to full text]

As advances in thin films are made there is a parallel requirement to develop equipment capable of measuring their properties accurately and consistently. In addition there is a need to understand the parameters that are measured. Typical DPI measurements allow both the refractive index (related to density) and the thickness of the adsorbed layer to be calculated with relatively few assumptions, to a very high precision in real time. This thesis presents the research undertaken to develop multiple path length dual polarisation interferometry (MPL-DPI) and absorption enhanced dual polarisation interferometry (AE-DPI). In addition research is presented that can be used to improve the interpretation of the measured parameters for inhomogeneous films and uniaxial films. The new Interferometric technique MPL-DPI allows the thickness and refractive index of in situ and ex-situ coated ultra-thin films to be measured. The procedures and the mathematics required to calculate the properties of films have been described and the technique verified. The technique was demonstrated using films of PMMA, where good agreement was found with complementary techniques. Furthermore, some key features of MPL-DPI were demonstrated using the measurements of interfacially grafted acrylic acid. The absorption enhanced DPI uses the attenuation of the light within the waveguide, due to the light absorbing properties of a film on its surface. As the composition of a film changed, it was shown that the refractive index and extinction coefficients could be used to separate the mass of the components of the film that absorbed light, from the components of the film that did not. With the use of a semi-uniaxial model, the extra data from the attenuation in two polarisations was used to fit the extraordinary and ordinary extinction coefficients. The extraordinary and ordinary extinction coefficients were used to demonstrate that molecular orientation could be implied. The influence that an inhomogeneous film has on the measured thickness, refractive index and extinction coefficient fitted by homogeneous models were investigated. Formulas are presented to explain the thickness, refractive index and extinction coefficient of the measured film. A formula for the total mass per unit area that uses the refractive index was created to account for films that contain molecules of different refractive index increments (dn/dc's). To separate the mass of the individual molecular species from the total mass per unit area, formulas that use the extinction coefficient were derived so molecules that absorb light could be separated from those that do not. The mass calculated from the refractive index and the mass calculated from the extinction coefficient were also examined for uniaxial films. For uniaxial films both measures of the adsorbed mass were found to be relatively accurate and benefited from a partial cancellation of errors. The accuracy of the measurements made by dual polarisation interferometry technology is systematically examined throughout this thesis. Improvements in the calibration routines are suggested and a procedure for the identification and reduction of errors in the phase and contrast is demonstrated.

En el presente estudio se ha analizado la actuación lingüística por parte de 22 estudiantes universitarios suecos en una prueba de traducción del sueco al español y una prueba de producción semi-libre en español. Fueron creadas dos pruebas distintas con los mismos ocho verbos, con la intención de suscitar construcciones verbales específicas en español, de manera que fuera posible, mediante un análisis de errores, comparar la actuación lingüística de los estudiantes y medir la proporción de errores atribuibles a la influencia interlingüística e intralingüística, a modo de comparación porcentual en ambas pruebas.  La transferencia de satélite direccional del sueco al español, motivada por la diferencia entre las lenguas- S y lenguas V, ha sido evidente en la prueba de traducción, mientras que en la prueba de producción semi-libre permanece prácticamente inexistente. De igual manera, se ha constatado la transferencia del sufijo -iv, -iva del sueco al español. Ambos rasgos mencionados se atribuyen a la influencia interlingüística, incrementada en un ejercicio de traducción. Los resultados indican que el ejercicio de traducción complica la exactitud gramatical e idiomática en la LM debido a una marcada influencia interlingüística, mientras que en el uso exclusivo de la LM en el ejercicio de producción semi-libre no parece ocurrir dicho fenómeno. Por consiguiente, la actividad contrastiva, en este caso, puede dificultar la exactitud gramatical y semántica en español como lengua extranjera. / In the present study, the linguistic performance of 22 Swedish university students in a translation test from Swedish to Spanish and a semi-free production test in Spanish has been analyzed. Two different tests were created with the same eight verbs, with the intention of eliciting specific verbal constructions in Spanish, so that it would be possible, through an analysis of errors, to compare the linguistic performance of the students and measure the proportion of errors attributable to the interlinguistic and intralinguistic influence, as a percentage comparison in both tests. Directional satellite transfer from Swedish to Spanish, motivated by the difference between S-languages ​​and V-languages, has been evident in the translation test, while in the semi-free production test it remains practically non-existent. Similarly, the transfer of the suffix -iv, -iva from Swedish to Spanish has been confirmed. Both features mentioned are attributed to the interlinguistic influence, increased in a translation exercise. The results indicate that the translation exercise complicates the grammatical and idiomatic accuracy in the ML due to a marked interlinguistic influence, while in the exclusive use of the ML in the semi-free production exercise this phenomenon does not seem to occur. Therefore, the contrastive activity, in this case, can hinder grammatical and semantic accuracy in Spanish as a foreign language.

<p>Probing the subsurface for evidence related to the degradation of porous mediums and the evolution of damage mechanisms has been a long-standing challenge in geophysics. As such imaging and predicting fracture network development has remained a difficult area for subsurface science for decades despite the seminal and significant works put forward by many researchers. While this has provide great understanding about the behaviours and properties of natural porous media, there is still much that needs to be explored particularly in regard to the mineralogical composition and chemistry of clay-rich rocks. Despite the fact that argillaceous rocks which consist of different types of clays and varied mineral composition are ubiquitous in nature and are often the target of several technologies (e.g. geotechnical engineering, nuclear waste storage and disposal,hydrocarbon exploration and extraction, carbon capture and sequestration, etc.), many studies focus primarily on the bulk properties or the percentage of components in the matrix. For these reason and due to the problems that can be encountered with natural rocks that contain a swelling clay component whether randomly distirbuted or localized in consolidated globs in zones of the matrix, the influence of clay chemistry in relation to fracture development which is not well characterized, especially during desaturation is investigated with analogue rock samples which were systematically fabricated for this purpose.</p> <p><br></p> <p>The research performed in this dissertation investigated, the applicability of  the fabrication protocol for developing synthetic rocks with desirable rock like features and behavior, the impact and relationship between the rock properties, the microstructural composition, water loss, and the macroscopic behavior of the analogue rocks, focusing on the structure and chemistry of the constituent clay materials. Synthetic rocks were fashioned with the necessary geometries, properties, and material compositions. On the macroscopic scale the fracture and drying behavior of the synthetic rocks were examined with 3D X-ray microscopy and further evaluated through the utility of acoustic emission monitoring, water loss monitoring, and unconfined compressive testing. On the finer scale (nano-microscale), the chemical and mechanical properties, and behavior of select clays was explored by exploiting several methods of material characterization which also included cation exchange experiments coupled with inductively coupled plasma – optical emission spectrometry (ICP-OES). </p> <p><br></p> <p>For the finer scale, experiments verified that calcined kaolinite clay had a different mineral structure and negligible to non-existence shrinkage abilities. In contrast, the montmorillonite clays possessed higher and similar moisture contents but, owing to the different principal cations these clays interacted a bit differently in the highly akaline environment, experienced varying degrees of shrinkage, and had observedly minor structural dissimilarities. For the relatively larger scale, the emergence of damage, extent of the damage network, and the patterns of the crack network mainly depended on the microstructural composition of the analogue rocks, particularly it's clay chemistry and/ or distribution. The location of damage depended on the emplacement and percentage of swelling clay in the matrix, and numerical investigations with peridynamics revealed that the observed damage was a consequence of the action of the swelling and non-swelling components of the matrix. Furthermore, if the microstructure consisted of no clay or calcined kaolinite the AE activity was solely attributed to interfacial processes that occurred during fluid front movement. If the microstructure consisted of a particular montmorillonite, the cracks propagated in the direction of the drying front. Conversely, for montmorillonite clay predominated by a different principal cation, the crack network developed and propagated differently during water loss. Additionally, on the laboratory core scale, properties and behavior similar to natural rocks were confirmed and the rock strength, porosity, AE activity, and velocities were primarily affected by the microstructural composition of the analogue rocks. </p> <p><br></p> <p>An added challenge for investigating and monitoring evolving systems and processes, whether on the laboratory or field scale, is the problem of extracting useful information from the physical data that can be used to identify signatures of developing processes, and changes in the properties or the behavior of a system. Here, data driven machine learning modeling and clustering techniques were undertaken to build a mechanistic understanding of the AE activity generated during drying. The intent is for this work to add to the fundamental research aimed at developing methods that will robustly detect and extract signatures related to evolutionary processes or features in the AE signals, and group them according to some degree of similarity. Such research will support reliable interpretations of the physical data for predictions of the behavior of systems, development of engineering controls, and improvement of the understanding of intrinsic dynamics related to complex processes particularly those that occur in clay-rich systems.</p> <p><br></p> <p>Combined chemical and mechanical investigations have great potential for unraveling practical challenges in subsurface science, especially regarding damage processes in clay-rich rock systems, and identifying and interpreting the presence of discontinuities from geophysical data. The present findings are useful for establishing a link between the constituent clay and observed damage, and improving our understanding of the development of damage in clay-bearing systems. These results provide insight on the influence of swelling clay and the chemistry of such clays on the generation of cracks and crack networks in rock like materials which can be useful for the characterization of damage in both laboratory and the field. The work presented here can also be a basis for further experiments that aim to uncover methods and protocols that will help with the indirect characterization of evolutionary processes, damage mechanisms, and damage in clay rich porous media. Additionally support for the use of analogue rocks in experimental rock physics, architected with specific material compositions, pore structures, crack systems, or clay fractions, is provided here. </p>

The transmission of electric power over long distances has historically posed challenges. However, the advent of high-voltage engineering has not only addressed distance barriers and power losses in electricity transmission and distribution, but it has also significantly improved the efficiency and transmission capacity of power grids. However, the use of high-voltage techniques has presented new challenges in identifying suitable insulator materials capable of withstanding high electrical stresses associated with elevated voltages. A significant issue arising from these extreme electrical stresses is the occurrence of partial discharges (PDs). Those are electrical sparks or pulses in the magnitude order of pico- or nano-coulombs (pC or nC) emitted from high voltage conductors due to the presence of impurities, contaminants or defects in their insulation system. PDs pose a serious threat to the insulation material due to their aggressive nature in breaking down weak points or links inside the insulation system leading to short-circuit and system failure. Means of offline or conventional testing of power assets against partial discharges has proven to be extremely precise but it is often an unavailable option since it requires a total power shutdown. In this paper, the performance of existing online PD detection techniques is tested and evaluated in terms of performance against conventional PD monitoring methods. Five non-intrusive detectors including an infrared camera (IR-camera), an ultrasonic sensor , a temperature and relative humidity sensor (TRH-sensor), high-frequency current transformer (HFCT sensor) and transient earth voltage antenna (TEV-antenna) were tested in a laboratory experiment for detection of PDs emitted by artificially-created defects inside a medium-voltage cable termination. The results showed varying sensitivity levels among the sensors, with the HFCT sensor demonstrating the highest sensitivity to all types and magnitudes of PDs. The IR-camera and ultrasonic sensor also showed potential, while the TRH-sensor exhibited poor sensitivity. The TEV-antenna had limited reliability. The findings of this study are that the HFCT system proved to be highly reliable for online PD monitoring, followed by the IR-camera and ultrasonic sensor, while the TEV-antenna and TRH-sensor showed lower reliability. In future work, further research on testing the HFCT system on-site can be conducted along with performing longer thermographic detection tests using the IR-camera to further investigate their potential in online PD detection. / Överföring av elektrisk kraft över långa avstånd har historiskt sett varit utmanande. Införandet av högspänningsteknik har inte bara övervunnit avståndsbarriärer och effektförluster vid överföring och distribution av elkraft, utan det har också avsevärt förbättrat kraftnätens effektivitet och överföringskapacitet. Användningen av högspänningsteknik har dock också inneburit nya utmaningar såsom utveckling av lämpliga isoleringsmaterial som tål höga elektriska påfrestningar vid höga spänningar. Ett betydande problem som härrör från dessa extrema elektriska spänningar är förekomsten av partiella urladdningar. Dessa urladdningar identifieras vara elektriska gnistor eller pulser i storleksordningen pico- eller nanocoulombs (pC eller nC) som emitteras från högspänningsledare på grund av närvaron av föroreningar eller defekter i närliggande isoleringssystem. PD:er utgör ett allvarligt hot mot isoleringsmaterialet på grund av deras aggressiva natur för att bryta ner svaga punkter eller länkar i isoleringssystemet, vilket kan leda till kortslutningar och systemfel. Konventionella metoder för att testa nätkomponenter mot partiella urladdningar har visat sig vara extremt noggranna, men detta är ofta inte ett tillgängligt alternativ eftersom det kräver ett totalt strömavbrott för att utföras. I denna studie testades och utvärderades prestandan hos befintliga metoder för online-detektering av partiell urladdning i förhållande till konventionella övervakningsmetoder. Fem icke-invasiva detektorer, inklusive en infraröd kamera, en ultraljudssensor, en temperatur- och relativ fuktighetssensor, en högfrekvent strömtransformator och en transient jordspänningsantenn, testades i ett laboratorieexperiment för att upptäcka partiella urladdningar orsakade av artificiellt skapade defekter i en mellanspänningskabelavslutning. Resultaten visade varierande känslighetsnivåer bland sensorerna, där högfrekventa strömtransformatorn visade den högsta känsligheten för alla typer och storlekar av partiella urladdningar. Den infraröda kameran och ultraljudssensorn visade också potential, medan temperatur- och relativ fuktighetssensorn visade låg känslighet. Den transienta jordspänningsantennen hade begränsad tillförlitlighet. Slutsatsen av denna studie är att den högfrekventa strömtransformatorn visade sig vara mycket tillförlitlig för online-övervakning av partiella urladdningar, följt av den infraröda kameran och ultraljudssensorn, medan den transienta jordspänningsantennen, temperatur- och fuktighetssensorn visade lägre tillförlitlighet. I framtida forskning kan ytterligare undersökningar av det högfrekventa strömtransformatorsystemet utföras på plats, tillsammans med längre termografiska detekteringstester med hjälp av den infraröda kameran för att ytterligare undersöka deras potential för onlinedetektering av partiella urladdningar.