The silver birch (Betula pendula Roth) and the downy birch (Betula pubescens Ehrh) are the most common broadleaved species in Swedish forests. Both species have a lot in common in appearance and are often misleadingly referred to simply as ”birch”. They have however different requirements and possibilities to grow on different sites. Downy birch grows well on moist and wet sites thanks to the fact that its roots are adapted to these type of environments. Silver birch has on the other hand the ability to grow on dry sites. Both species prefer soil moisture class somewhere in between wet and dry.   To be able to promote the correct birch species on each site, it is important to identify the two species during the clearing process. Both buds and shoots are characteristic for each species why those parts can be used to separate them. Buds from silver birch are pointy shaped and those from downy birch are round shaped. When it comes to shoots the silver birch has nubby shoots and the downy birch has hairy shoots.  The aim of this study was to a) investigate the occurrence of each of the two birch species on sites with different soil moisture class, b) investigate if it was possible to visually identify each species during clearing with a clearing saw and c) to find out if and how the height of the stand influenced the possibility of species identification. This study shows that it is possible to identify the two species. It is however important to start the clearing process at an early age, since the parts of the tree used for identification otherwise will grow beyond sight.  This is particularly important on moist sites, where both birch species regenerate willingly. In the long run, downy birch will have higher ability to develop high quality timber on these sites. In order to do that, the right stems must be chosen at each clearing occasion. It is important to start the clearing process at an early age, since the characteristic parts of the tree otherwise will grow beyond sight.  Keywords

This work has been carried out on behalf of and together with Falu Energi och Vatten. The purpose of the work was to study under what circumstances it´s economically profitable to expand the district heating network to residential area with electrical heating compared to keep it as it is today. The expansion of the district heating network will also be simulated to investigate if the existing dimensions of the network are big enough to provide enough heat after the expansion. In this work three different areas in Falun city area has been studied. Two areas (Ritar-, and Skrivarvägen and Digertäktsvägen) where there is no district heating today, and one area (residential district Haraldsbo) where a part of the area is connected to the district heating network and some are not. The study has been performed under the assumption that the production in the facilities are sufficient for providing also the new areas with heat without any need of new facilities. Another limitation that has been set is that only fuel costs will be taken into account in the production costs for district heating. From the calculations of the net present value for the three different areas with expansions of the district heating system, compared to the calculations of the net present value of keeping it as it is today showed that Ritar-, and Skrivarvägen will need to have at least 30-35% households connected to have the same or higher net present value. The corresponding values for Digertäktsvägen is 35-45% connected households and för Haraldsbo around 15% connected households. It was also examined how the connection rates influenced the prize for the households, if the net present value was going to be equal or bigger than for the present situation without any connection cost.  It was found that for Harladsbo where there already are some households with district heating only 15% of the today not connected needed to sign up for district heating and in the areas that does not have any district heating today (Ritar-, and Skrivarvägen and Digertäktsvägen) 50-70% needed to sign up for district heating. “Falu Energi och Vatten” calculations today demand a payback time of 12 years of the investment in the district heating infrastructure. To get that 30 -40% needed to connect in Ritar-, and Skrivarvägen and Digertäktsvägen, on Haraldsbo the connection rate had to be over 15%. The results from the simulations made on the district heating infrastructure showed that on Ritar-, and Skrivarvägen the network is sufficient to supply the whole area with heat at the dimensional outdoor temperature of -23°C, also with 100% connections on Haraldsbo the pressure difference, flow speed and pressure gradient are within the permitted span. Simulations of Haraldsbo showed that with a connection rate of 100% the pressure difference got to low in one corner of the area. If the connection rate instead is 50% at Haraldsbo the area manage to keep the pressure difference at an approved level of 160 kPa, if we then also connect 100% at Ritar-, and Skrivarvägen, the pressure difference sinks down to 100 kPa which is the absolute lowest that is permitted.

In Sweden, June 1, 2014, law 2014: 266 on energy mapping in large companies came into force. An energy mapping is a map of the company's energy use. It describes what type of energy carrier is used, electricity, district heating, fuel, and how big the consumption is. It also describes the part in which this energy is used within the company, for example in business or transport. The purpose of making an energy mapping is to get an overview of the consumption of energy in the company and to find possible actions to reduce the consumption and the cost for energy. This energy mapping deals with Norconsult's 18 offices operations in Sweden. The project also includes Norconsult Fältgeoteknik AB, a subsidiary of Norconsult. The result from the energy mapping was that the total energy consumption for the company 2016 was 3 588 MWh. The total cost of all consumed energy is estimated to approximately 3 100 000 SEK in 2016. The energy consumption of the company is divided into three different uses, district heating, electricity and transport. From the result the total use for the transport accounts for 56 percent of total consumption, 26 percent of transportation is Norconsult's consumption of gasoline and 20 percent is Norconsult Fältgeoteknik's consumption of diesel. 21 percent of the total consumption is electricity, and 20 percent is district heating.  Based on the overall energy use, examples for energy reductions have been made for the various areas, which has given an opportunity to improve energy use at the company Norconsult. The suggestions are presented below.  The Gothenburg office uses district heating and district cooling. For several months in 2016, these systems were running simultaneously. The conclusion is that there is a significant savings possibility, as there is no need for costing to fix the problem, just an adjustment of the control of heat and cooling. Monitors and computers are often in sleep mode during evenings and weekends, which causes unnecessary energy. By establishing routines for shutting down screens, computers and printers, it can make energy saving of 2.4 percent of total electricity consumption.   In 2016 Norconsult personnel flew 159 times from Stockholm to Gothenburg. This resulted in an increased energy consumption of 13.18 MWh compared to if the travels were made by train. This amount stands for 0.37 percent of the total energy consumption, which is not very much. However, air transport consumes energy through combustion of aviation fuel, while energy consumption for trains is by electricity. Electricity is a much purer source of energy emissions, which results in a reduced environmental impact. The conclusion it that it is possible to save both money, time and reducing the negative effect on the environment by switching from flights to rail transport.

För att övervaka utvecklingen i Sveriges sjöar och vattendrag används bland annat klassning av ekologisk- och kemisk status. Dessa faktorer ger information över vattendragets status och innefattar ett flertal parametrar som sammanställs till en slutlig klassning. Tökilsbäcken är en sju kilometer lång naturlig bäck som har sitt utlopp i Gavleån. Bäcken rinner till största del genom ett skogslandskap, ungefär tre kilometer uppströms utloppet finns en mindre tillrinningsbäck där en deponiverksamhet släpper ut sitt renade lak- och dagvatten. För att klassa särskilda förorenande ämnen i Tökilsbäcken hämtades årsmedelvärde för god status för metallerna koppar, krom och zink. Vid klassning av kemisk status har gränsvärden för metallerna bly, kadmium och nickel inhämtats. Samtliga begränsande värden är inhämtade från Havs och vattenmyndighetens föreskrifter om klassificering och miljökvalitetsnormer (HVMFS, 2013). En sammanställning av befintliga provtagningsrapporter under åren 2011-2018 från tre provtagningspunkter, analyser av metallhalter i vattenmossor och bottenfauna (Internt material, SUEZ) utfördes och sammanställdes i text och grafer. Resultatet av denna studie är att särskilda förorenande ämnen, som ingår i klassning av ekologisk status erhåller klassningen god status med avseende på koppar, krom och zink i de två provtagningspunkter belägna i Tökilsbäcken. Vid den tredje provpunkten belägen uppströms i tillrinningsbäcken blir klassningen uppnår ej god status på grund av det förhöjda årsmedelvärdet av krom år 2011. Vid klassning av kemisk status uppnås god kemisk ytvattenstatus vid samtliga provpunkter under tidsperioden 2011-2018 med avseende på bly, kadmium och nickel. Sammanställning visar att metallerna koppar, zink och bly har högst halterna uppströms, därefter nedströms och lägst vid provpunkt utlopp. För metallerna krom och nickel är halterna störst vid provpunkt utlopp, därefter nedströms och lägst halter uppmätts vid provpunkt uppströms. För kadmiumhalterna ses en ökning över tid men endast marginella skillnader mellan de tre provpunkterna. Om endast påverkan från dessa sex metaller undersöks, dras slutsatsen att utsläppen av krom och nickel, den ökande halten av kadmium eller inverkan av cocktaileffekten är vad som med största sannolikhet ger upphov till försämringen i bottenfauna vid provpunkt nedströms i jämförelse med uppströms. Trots dessa lovande resultat finns osäkerhet kring klassning av verktyget för uträknande av biotillgänglighet då ingen eller väldigt små kopplingar kunde göras mellan undersökningar utförda av metallhalter i vattenmossor och halten biotillgängliga metaller. Även problematik kring gränsvärden och att utsläppen av metaller sker i koncentrationer och inte faktisk utsläppt mängd diskuteras. / In order to monitor environmental changes in Swedish lakes and watercourses, a classification of ecological and chemical status was evaluated. These factors provide information on the status of the watercourse and include a number of parameters that are put together into a final classification. Tökilsbäcken is a seven-kilometre natural watercourse that has its effluent in Gavleån. The watercourse flows mostly through a forest landscape. Approximately three kilometres upstream of the effluent, there is an outlet to Tökilsbäcken from a small stream where a landfill lets out it´s purified leachate. To classify what is called specific pollutants in Swedish environmental legislation the annual average values were obtained for good status for the metals copper, chromium and zinc. These three metals are a part of the classification of ecological status. When investigating the classification for chemical status, limit values for the metals was obtained for lead, cadmium and nickel. All limiting values have been obtained from Havs- och vattenmyndighetens regulations on classification and environmental quality standards (HVMFS, 2013). A compilation of existing sampling reports during the years 2011-2018 from three sampling points, analyses of metal contents in water mosses and bottom fauna (Unpublished material, SUEZ) was performed and compiled in text and graphs. The result of this study shows that the three metals included in the classification of ecological status receive classification good status concerning copper, chromium and zinc in the two sampling points located in Tökilsbäcken. At the third test point located upstream of the small stream, the classification will not achieve good status due to the increased annual average value of chromium in 2011. When chemical status was classified, good chemical surface water status was achieved at all test points over the period 2011-2018 concerning lead, cadmium and nickel. When analysing annual average values the levels of copper, zinc and lead where highest at sample point upstream, then downstream and the lowest levels where found in the outlet. For the metals chromium and nickel the highest levels where found in sample point outlet, then downstream and the lowest values where found in upstream. The levels of cadmium has increased over time but only marginal differences where seen for the three sample points. Only regarding the six investigated metals it is concluded that the emissions of chromium, nickel the increased levels of cadmium or the cocktaileffect are most likely to the degradation of bottom fauna downstream compared to upstream. Despite these promising results, there is some uncertainties about the tool for calculating bioavailability. This because no or very small correlation could be found between samplings of metal contents in water mosses and the levels of bioavailable metals in the watercourse. Also, issues concerning limit values and that the limits for metals occur in concentrations and not in actual amounts of metals, are discussed.

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Detta arbete behandlar förekomsten av botar i sociala medier. Hur implementeras egentligen botar på en social medieplattform? Vad kan dessa botar utföra och vad innebär det för vårt samhälle? Botar kan ses ur flera perspektiv och bidrar med både negativa och positiva aspekterna. Frågor likt dessa besvaras i detta arbete och fokus ligger på plattformen Twitter. Med hjälp av en litteraturstudie och ett experiment redogörs för hur en bot kan implementeras, detekteras och vad för syften en bot kan inneha på plattformen.Fokus ligger på hur detektionsalgoritmer kan användas i syfte att detektera illasinnade botar och hur effektiva algoritmerna kan anses vara. Arbetets experiment redgör för hur man kan med enkla medel implementera sin egna bot på plattformen och vad det finns för möjligheter när det kommer till vilka funktioner en sådan bot kan utföra. Arbetet ger ett samhällsperpektiv på effekten av botar på sociala medier i exempelvis valkampanjer och hur botar kan påverka och lura människan. Historien bakom botens uppkomst och en teoretisk del som ger en förklaring för hur en avancerad bot arbetar möjliggör en bra grund för läsaren att stå på för att skapa sig en egen uppfattning om problematiken kring botar i sociala medier. Resultaten visar att sociala mediebotar kan ses som en form av verktyg som kan användas på gott och ont. Litteraturstudien visar att detär viktigt att riktlinjer följs så att dessa botar inte används för att vilseleda människor. Botar kan och har använts i både politiska och ekonomiska syften för att påverka opinion eller vilseleda människor i form av phishing attacker. Experimentet visar hur tillgången till Twitters API och implementationen av en Twitterbot går till rent praktiskt. Resultaten här visar att det utan större programmeringskunskap går att implementera interaktiva botar på Twitters plattform. Detta arbete lyckades implementera Eliza på Twitter som en interaktiv chatbot.

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The surge in the use of adaptive Artificial Intelligent (AI) systems have been made possible by leveraging the increasing processing and storage power that modern computers are able to provide. These systems are designed to make quality decisions that assist in making predictions in a wide variety of application fields. When such a system is fueled by data, the foundation for a Machine Learning (ML) approach can be modelled. Reinforcement Learning (RL) is an active model of ML going beyond the traditional supervised or unsupervised ML methods. RL studies algorithms to take actions so that the resulting reward is expected to be optimal. This thesis investigates the use of methods of RL in a context where the reward is highly time-varying: a setup is studied where two agents compete for a common resource. Specifically, we study a robotic setting inspired by the "cat-and-mouse" (hunter-prey) game. We refer to the hunter robot as to Tom, and to the competing prey robot as Jerry. In order to study this setup, two practical setups are considered. The first one is based on a LEGO platform, enabling us to run a number of actual experiments. The second one is based on a known RL simulator environment, enabling us to run many virtual experiments. We use these environments to explore the setting: indicate the non-stationary solution it generates, evaluate a number of de-facto standard approaches to RL, and identify key future avenues to be addressed.

A simple solver for linear integer systems is designed and accelerated on aCycloneV SoC chip that contains Cortex-A based MCU, programmable FPGA, andinter-connect bridges. The solver is designed based on the Gaussian Elimination method, where a system coefficient matric is converted to a Row-Echelon matrix and performing back Back-Substitution to solve system variables. The matrix conversion is implemented in the FPGA with serial and parallel architectures, where the processing of two equations is performed using single and multiple reducer modules. In comparison with the software-based solver, the solver with hardware based-based matrix conversion modules are faster by at least 75% despite very high MCU clock and data transfer overhead between the subsystems.

The work proposes an update in the maneuvering of the capacitator filters in the 400/690 V substations. Two of the capacitator filters are not in operation due to missing control circuits which we have constructed electrical schematics for. Also I have constructed a draft for the maneuvering of 5 capacitator filters on the 6 kV electrical grid but it´s not commissioned. The work also resulted in a proposition that the three capacitator filters which were bought after the substation fire in 2008 are installed for a cost of 550 thousand Swedish kronor, the proposition will theoretically yield a yearly decrease of outlay by 160 thousand Swedish kronor. / Arbetet har resulterat i en uppdatering av styrningen för de kondensatorfilter som finns i 400/690 V ställverken. Det är även framtaget kretsscheman för att kunna ta i drift två kondensatorfilter som ej varit i drift sedan tidigare. Det är framtaget ett förslag för styrning av 5 stycken kondensatorfilter på 6 kV-nätet men det är ej implementerat. Det är även framtaget ett förslag att installera de 3 kondensatorfilter som blivit inköpta efter ställverksbranden 2008 men som inte blivit installerade. Investeringen skulle kosta 550 tusen kronor och minskar teoretiskt den årliga kostnaden med 160 tusen kronor.