Integration of European electricity market is one of the major challenges since the begin-ning of the 2000s. In 2010, market coupling, which optimizes power trading by allocating cross-border transmission capacity, was launched in Central West Europe (CWE). It was first implemented by using the Available Transmission Capacity (ATC) based capacity transmission. The ATC method was based on computation of Net Transfer Capacity on each border of the CWE zone by Transmission System Operators. On May 21st 2015, ATC method was replaced by the flow-based method. The flow-based method better takes into account the network specificities. It allocates transmission capacity based on branches rather than borders, as it was the case with ATC method.   Traders need to forecast the spot price in order to best choose their trading strategy. They have to forecast weather conditions, consumption, production and network main-tenance. With the implementation of the flow-based method, now they also need to forecast the flow-based domain. Then, clustering on past data will help to fulfill this goal.   This thesis has been carried out in three main steps. First, ATC and flow-based methods have been compared each other in order to better understand what are the advantages with the flow-based method. Then, main achievements and features of the flow-based method have been highlighted based on data collected during the phase test. Finally, a procedure has been developed in order to cluster data which define the flow-based domain. The clustering procedure has been tested on data collected of January 2015. Different clustering methods and observation pre-processing have been compared and recommendations on the best choice have been made.

Programmering kan stundtals vara utmanande även för den erfarna. Det finns mängder med olika programmeringspråk som alla i sin tur har olika syntax. Programmering blir även allt mer vanligt i yrken som inte jobbar primärt inom IT. Det är därför viktigt att sänka inlärningskurvan för oerfarna programmerare.I denna studie undersöker vi vad visualisering av ett scriptspråk kan göra för att sänka inlärningskurvan och vilka potentiella fördelar eller nackdelar det för med sig. Studien utgår från aktuell forskning vid ett företag med syftet att utforma en prototyp som visualiserar ett scriptspråk. Användartester i form av intervjuer används sedan för att testa prototypen på olika målgrupper. Resultatet av intervjuerna visar att visualiseringen är till användning för både erfarna och oerfarna användare. Användingsområdena skiljer sig dock beroende på vilken erfarenhet användaren har. Det krävs därför vidare forskning för att implementera en visualisering som är anpassad för olika typer av användare. / Programming can sometimes be challenging even for the experienced. There are lots of different programming languages, each of which has different syntax. Programming is also becoming more common in professions that do not work primarily in IT. It is therefore important to lower the learning curve of inexperienced programmers.In this study we investigate what visualization of a scripting language can do to lower the learning curve and what potential benefits or disadvantages it entails. The study is based on current research at a company with the purpose of designing a prototype that visualizes a scripting language. User tests in the form of interviews are then used to test the prototype on different target groups. The results of the interviews show that the visualization is useful for both experienced and inexperienced users. The uses differ, however, depending on the experience the user has. Further research is therefore required to implement a visualization that is adapted to different types of users.

<p>Flow-based microfluidic biochips constitute an emerging technology for the automation of biochemical procedures. Recent advances in fabrication techniques have enabled the development of these devices. Increasing integration levels provide biochips with tremendous potential; a large number of bioassays, i.e., protocols for biochemistry, can be processed independently, simultaneously, and automatically on a coin-sized microfluidic platform. However, the increases in integration level introduce new challenges in the design optimization and the testing of these devices, which impede their further adoption and deployment.</p><p>This thesis is focused on enhancing the automated design and use of flow-based microfluidic biochips and on developing a set of solutions to facilitate the full exploitation of design complexities that are possible with current fabrication techniques. Four key research challenges are addressed in the thesis; these include design automation, wash optimization, testing, and defect diagnosis.</p><p>Despite the increase in the number of on-chip valves, designers are still using full-custom methodologies involving many manual steps to implement these chips. Since these chips can easily have thousands of valves, manual design procedure can be time-consuming and error-prone, and it can result in inefficient designs. This thesis presents the first problem formulation for automated control-layer design in flow-based microfluidic biochips and describes a systematic approach for solving this problem. Our goal is to find an efficient routing solution for control-layer design with a minimum number of control pins.</p><p>The problem of contamination removal in flow-based microfluidic biochips must also be addressed. Applications in biochemistry require high precision to avoid erroneous assay outcomes, and they are vulnerable to contamination between two fluidic flows with different biochemistries. This thesis proposes the first approach for automated wash optimization for contamination removal in flow-based microfluidic biochips. The proposed approach ensures effective cleaning and targets the generation of wash pathways to clean all contaminated microchannels with minimum execution time under physical constraints.</p><p>Another practical problem addressed in this thesis is the lack of test techniques for screening defective biochips before they are used for biochemical analysis. This thesis presents an efficient approach for automated testing of flow-based microfluidic biochips. The test technique is based on a behavioral abstraction of physical defects in microchannels and valves. The flow paths and flow control in the microfluidic device are modeled as a logic circuit composed of Boolean gates, which allows test generation to be carried out using standard automatic test-pattern generation tools. Based on the analysis of untestable faults in the logic-circuit model, we present a design-for-testability technique that can achieve 100\% fault coverage.</p><p>Finally, this thesis presents a technique for the automated diagnosis of leakage and blockage defects. The proposed method targets the identification of defect types and their locations based on test outcomes. It reduces the number of possible defect sites significantly while identifying their exact locations.</p><p>In summary, this thesis has led to a set of optimization and testing methods for flow-based microfluidic biochips. The results of this research are expected to not only shorten the product development cycle, but also accelerate the adoption and further development of this emerging technology by facilitating the full exploitation of design complexities that are possible with current fabrication techniques.</p> / Dissertation

This study discusses the routing optimization techniques and algorithms for communication networks. Preventing data loss on overloaded communication links and utilizing link bandwidths efficiently are the main problems of traffic engineering. Load balancing and routing problems are solved using both by heuristics such as genetic algorithms, and simulation techniques. These algorithms work on destination-based or flow-based routing techniques and mainly change the link weight system or try to select the best routes set upon K-routes routing table respectively to optimize network utilization. In this study, first a definition of the network routing optimization problem will be made. Then the heuristics to solve the problem will be discussed and finally an analysis of these heuristics will be made on sample network models. This thesis includes a discussion about the performance of different optimization heuristics working as a part of the centralized network load balancing systems.

Please read the abstract in the section 00front of this document / Thesis (PhD)--University of Pretoria, 2010. / Chemistry / unrestricted

As the networks become faster and faster, the emerging requirement is to improve the performance of the Intrusion Detection and Prevention Systems (IDPS) to keep up with the increased network throughput. In high speed networks, it is very difficult for the IDPS to process all the packets. Since the throughput of IDPS is not improved as fast as the throughput of the switches and routers, it is necessary to develop new detection techniques other than traditional techniques. In this thesis we propose a rule-based IDPS technique to detect Layer 2-4 attacks by just examining the flow data without inspecting packet payload. Our approach is designed to work as an additional component to existing IDPS as we acknowledge that the attacks at Layer 5 and above require payload inspection. The rule set is constructed and tested on a real network to evaluate the performance of the system.

Die kumulative Dissertationsschrift besteht aus zwei Teilen. Der erste Teil beleuchtet die Auswirkungen von erhöhten Mengen stromerzeugender erneuerbarer Energien auf den deutschen Strommarkt. In drei Papieren werden die Effekte von erneuerbaren Energien auf die Handelsbilanz, die Emissionsreduktionen und die Preisunsicherheit im Intraday-Markt in Deutschland mit Hilfe von Regressionsanalysen quantifiziert. Der zweite Teil adressiert die Kapazitätsberechnungen für internationalen Stromhandel im Rahmen von Flow-based Market Coupling. Diese Methodik löst sukzessive die bilateralen Handelskapazitäten ab und basiert ihre Kapazitätsbestimmung auf Netzberechnungen und einer Quantifizierung, wie sich Handel auf einzelne kritische Netzwerkelemente auswirkt. Dies ermöglicht im Durchschnitt höhere Handelskapazitäten, was zur Erreichung der deutschen und europäischen Ziele – hohe Versorgungssicherheit, bezahlbare Strompreise, bessere Integration von erneuerbaren Energien und schließlich die Dekarbonisierung der Stromsysteme – einen sehr wichtigen Beitrag leistet. In fünf Papieren werden einerseits statistische Ansätze für wichtige Prognoseparameter im Flow-based Market Coupling entwickelt, insbesondere Generation Shift Keys und die Prognose von konventionellem Kraftwerkseinsatz. Andererseits werden Optimierungsmodelle entwickelt, die den Prozess von Flow-based Market Coupling – Engpassprognose und Marktkopplung – komplett abbilden. Diese Schritte werden durch Engpassmanagement-Berechnungen ergänzt, um aktuelle Fragestellungen zu beantworten, wie z.B. die Wohlfahrtseffekte von Mindesthandelskapazitäten.:Summary Acknowledgments List of Figures Nomenclature and short definitions A Introductory background, research questions and conjunction of research articles A.1 Energy political goals and challenges of the European Union A.2 Fundamentals of electricity price formation, market coupling and congestion management A.2.1 The merit order: Formation of electricity prices in a country A.2.2 Market coupling: Enabling cross-border trade of electricity A.2.3 Congestion management: Averting the violation of physical grid constraints A.2.4 Trading capacities: Limiting cross-border exchange of electricity as a form of preventative congestion management A.2.5 Flow-based market coupling: Combining trading capacities, market coupling and congestion management A.3 Addressing the research questions A.3.1 Overview of articles as part of this cumulative dissertation A.3.2 Brief overview of used methods to address the research questions A.3.3 Relation and coherence of articles A.3.4 Main findings of articles A.3.5 Concluding remarks and further research References B Published and submitted articles B.1 Parsing the Effects of Wind and Solar Generation on the German Electricity Trade Surplus B.2 What caused 2019’s drop in German carbon emissions: Sustainable transition or short-term market developments? B.3 The effect of corrective short-term updates for wind energy forecasts on intraday electricity prices B.4 The impact of different strategies for generation shift keys (GSKs) on the flow-based market coupling domain: A model-based analysis of Central Western Europe B.5 Zone-wide prediction of generating unit-specific power outputs for electric grid congestion forecasts B.6 An Improved Statistical Approach to Generation Shift Keys: Lessons Learned from an Analysis of the Austrian Control Zone B.7 Do minimum trading capacities for the cross-zonal exchange of electricity lead to welfare losses? B.8 Toward a fundamental understanding flow-based market coupling for crossborder electricity trading

In the early days of computer graphics, research was mainly driven by the goal to create realistic synthetic imagery. By contrast, non-photorealistic computer graphics, established as its own branch of computer graphics in the early 1990s, is mainly motivated by concepts and principles found in traditional art forms, such as painting, illustration, and graphic design, and it investigates concepts and techniques that abstract from reality using expressive, stylized, or illustrative rendering techniques. This thesis focuses on the artistic stylization of two-dimensional content and presents several novel automatic techniques for the creation of simplified stylistic illustrations from color images, video, and 3D renderings. Primary innovation of these novel techniques is that they utilize the smooth structure tensor as a simple and efficient way to obtain information about the local structure of an image. More specifically, this thesis contributes to knowledge in this field in the following ways. First, a comprehensive review of the structure tensor is provided. In particular, different methods for integrating the minor eigenvector field of the smoothed structure tensor are developed, and the superiority of the smoothed structure tensor over the popular edge tangent flow is demonstrated. Second, separable implementations of the popular bilateral and difference of Gaussians filters that adapt to the local structure are presented. These filters avoid artifacts while being computationally highly efficient. Taken together, both provide an effective way to create a cartoon-style effect. Third, a generalization of the Kuwahara filter is presented that avoids artifacts by adapting the shape, scale, and orientation of the filter to the local structure. This causes directional image features to be better preserved and emphasized, resulting in overall sharper edges and a more feature-abiding painterly effect. In addition to the single-scale variant, a multi-scale variant is presented, which is capable of performing a highly aggressive abstraction. Fourth, a technique that builds upon the idea of combining flow-guided smoothing with shock filtering is presented, allowing for an aggressive exaggeration and an emphasis of directional image features. All presented techniques are suitable for temporally coherent per-frame filtering of video or dynamic 3D renderings, without requiring expensive extra processing, such as optical flow. Moreover, they can be efficiently implemented to process content in real-time on a GPU. / In den Anfängen der Computergrafik war die Forschung hauptsächlich von dem Anspruch getragen, realistisch aussehende synthetische Bilder zu erstellen. Im Gegensatz dazu ist die nicht-photorealistische Computergraphik, ein Untergebiet der Computergrafik, welches in den frühen 1990er Jahren gegründet wurde, vor allem motiviert durch Konzepte und Prinzipien der traditionellen Kunst wie Malerei, Illustration und Grafikdesign. Diese Arbeit beschäftigt sich mit der künstlerischen Verarbeitung von zweidimensionalen Bildinhalten und präsentiert mehrere neue automatische Verfahren für die Erstellung von vereinfachten künstlerischen Darstellungen von Farbbildern, Videos und 3D- Renderings. Wichtigste Neuerung dieser Techniken ist die Verwendung des Strukturtensors als eine einfache und effiziente Möglichkeit, Informationen über die lokale Struktur eines Bildes zu erhalten. Konkret werden die folgenden Beiträge gemacht. Erstens wird eine umfassende übersicht über den Strukturtensor gegeben. Insbesondere werden verschiedene Methoden für die Integration des kleineren Eigenvektorfeldes des geglätteten Strukturtensors entwickelt, und die Überlegenheit des geglätteten Strukturtensors gegenüber dem populären Edge-Tangent-Flow demonstriert. Zweitens werden separable Implementierungen des bilateralen Filters und des Difference of Gaussians Filters vorgestellt. Durch die Anpassung der Filter an die lokale Struktur des Bildes werden Bildfehler vermieden, wobei der Vorgang rechnerisch effizient bleibt. Zusammengenommen bieten beide Techniken eine effektive Möglichkeit, um einen Cartoon-ähnlichen Effekt zu erzielen. Drittens wird eine Verallgemeinerung des Kuwahara-Filters vorgestellt. Durch die Anpassung von Form, Umfang und Orientierung der Filter an die lokale Struktur werden Bildfehler verhindert. Außerdem werden direktionale Bildmerkmale besser berücksichtigt und betont, was zu schärferen Kanten und einem malerischen Effekt führt. Neben der single-scale Variante wird auch eine multi-scale Variante vorgestellt, welche im Stande ist, eine höhere Abstraktion zu erzielen. Viertens wird eine Technik vorgestellt, die auf der Kombination von flussgesteuerter Glättung und Schock-Filterung beruht, was zu einer intensiven Verstärkung und Betonung der direktionalen Bildmerkmale führt. Alle vorgestellten Techniken erlauben die zeitlich kohärente Verarbeitung von Einzelbildern eines Videos oder einer dynamischen 3D-Szene, ohne dass andere aufwendige Verfahren wie zum Beispiel die Berechnung des optischen Flusses, benötigt werden. Darüberhinaus können die Techniken effizient implementiert werden und ermöglichen die Verarbeitung in Echtzeit auf einem Grafikprozessor (GPU).

Biped robots with serial links driven by an electric motor experience problems because the motor and transmission are installed in each joint, causing the legs to become very heavy. Previous solutions involved robots using servo valves, a type of highly responsive proportional valve. However, high supply pressure is necessary to realize high responsiveness and the resulting energy losses are large. To address this problem, we proposed a hydraulic direct-drive system in which the pump controls the cylinder meter-in flow, while a proportional valve controls the meter-out flow. Furthermore, our hydraulic interlocking drive system connects two hydraulic direct-drive systems for biped humanoid robots and concentrates the pump output on one side cylinder. The meter-in flow rate of the other side cylinder is controlled by the meter-out flow rate of the cylinder on which the pump is concentrated. A comparison of the walking simulation performance with that of the conventional independent system shows that our proposed system reduces the motor output power by 24.3%. These results prove the feasibility of constructing a two-legged robot without having to incorporate highly responsive servo valves.

With recent advancements, image generation has become more and more possible with the introduction of stronger generative artificial intelligence (AI) models. The idea and ability of generating non-existing images that highly resemble real world images is interesting for many use cases. Generated images could be used, for example, to augment, extend or replace real data sets for training AI models, therefore being capable of minimising costs on data collection and similar processes. Deep learning, a sub-field within the AI field has been on the forefront of such methodologies due to its nature of being able to capture and learn highly complex and feature-rich data. This work focuses on deep generative learning approaches within a forestry application, with the goal of generating tree log end images in order to enhance an AI model that uses such images. This approach would not only reduce costs of data collection for this model, but also many other information extraction models within the forestry field. This thesis study includes research on the state of the art within deep generative modelling and experiments using a full pipeline from a deep generative modelling stage to a log end recognition model. On top of this, a variant architecture and image sampling algorithm are proposed to add in this pipeline and evaluate its performance. The experiments and findings show that the applied generative model approaches show good feature learning, but lack the high-quality and realistic generation, resulting in more blurry results. The variant approach resulted in slightly better feature learning with a trade-off in generation quality. The proposed sampling algorithm proved to work well on a qualitative basis. The problems found in the generative models propagated further into the training of the recognition model, making the improvement of another AI model based on purely generated data impossible at this point in the research. The results of this research show that more work is needed on improving the application and generation quality to make it resemble real world data more, so that other models can be trained on artificial data. The variant approach does not improve much and its findings contribute to the field by proving its strengths and weaknesses, as with the proposed image sampling algorithm. At last this study provides a good starting point for research within this application, with many different directions and opportunities for future work.