Die zu erwartenden Temperaturen und Regenmengen der folgenden Tage bis Stunden sind heutzutage eine der wichtigsten Informationen. Diese Kenntnis ist nicht nur von allgemeinem Interesse. Insbesondere Bereiche wie die Landwirtschaft und Forstwirtschaft sind die zu erwartenden Regenmengen selbst über einen langen Zeitraum von Wochen von besonderen Interesse um zum Beispiel die Ernte oder den Schutz von Pflanzen zu planen. Daher ist die Fähigkeit, das Wetter zuverlässig und schnell für ausreichend lange Zeiträume vorher zu sagen, wesentlich. Die Zuverlässigkeit der Wettervorhersage, oder genau genommen der numerischen Wettervorhersage, hängt von mehreren Faktoren ab. Einer dieser Faktoren ist die Detailliertheit der Atmosphärenmodelle. Während die ersten numerischen Experimente die Atmosphäre als eine Schicht trockenen idealen Gases betrachteten, beinhalten aktuelle Modelle die Feuchte, Wolken, Niederschlag und Strahlung. Mit jedem zusätzlichen Detail steigt natürlich der Simulationsaufwand. Daher müssen parallel zur verbesserten Modellierung auch die numerischen Verfahren erweitert werden. Im allgemeinen sind die Atmosphärenmodelle Systeme nichtlinearer hyperbolischer Differentialgleichungen (PDEs). Insbesondere beinhalten die Modelle Wellen unterschiedlicher Ausbreitungsgeschwindigkeit, welche nahezu nicht gedämpft werden. Diese unterschiedlichen Geschwindigkeiten sind die Grundlage für den Mehrskalencharakter der Atmosphärenmodelle. Eine effektive numerische Methode muss daher die unterschiedlichen Skalen adäquat behandeln. Die Entwicklung und Analyse numerischer Mehrskalenverfahren zur Lösung von Systemen hyperbolischer Differentialgleichungen ist herausfordernd. Beispiele für hyperbolische Systeme beginnen bei der einfachen skalaren linearen Advektionsgleichung, der Wellengleichung und enden bei nichtlinearen Systemen wie den Flachwassergleichungen oder den (reibungsfreien) Eulergleichungen. Letztere sind die Grundlage für alle Atmosphärenmodelle. Viele hyperbolische PDEs besitzen eine additive Struktur, wobei die Aufteilung gerade den Zeitskalen entsprechen. Wir gehen von einer angepassten Diskretisierung im Raum, in der Regel eine Finite-Volumen Diskretisierung, aus. Diese Diskretisierung erhält die additive Struktur des kontinuierlichen Problems in der (ortsdiskretisierten) gewöhnlichen Differentialgleichung (ODE). Daher entwickeln wir eine neue numerische Methode zur Lösung gewöhnlicher Differentialgleichungen, welche die additive Struktur und gleichzeitig die zugehörigen Zeitskalen ausnutzt. Die Analyse von Splittingverfahren ist herausfordernd sowohl in der Entwicklung der Ordnungsbedingungen als auch der Stabilitätskriterien. Jeder Mehrskalenansatz kombiniert die unterschiedlichen Zeitskalen auf unterschiedliche Art und Weise. Daher gibt es keine einheitliche Ordnungs- und Stabilitätstheorie. Wir entwickeln die Ordnungsbedingungen auf klassischem Wege, durch Differentiation der numerischen Lösung. Die Aufteilung der rechten Seite in schnelle und langsame Terme führt auf zusätzliche Koeffizienten und Kombinationen der elementaren Differentiale. Im Vergleich zu klassischen Verfahren hat jedes elementare Differential unterschiedliche nicht-klassische Koeffizienten, ohne erkennbare Struktur. Dieser Strukturverlust erschwert die numerische Lösung zusätzlich. Analytische Lösungen gibt es nur in Sonderfällen. Wir entwickeln und analysieren eine neue Klasse von Mehrskalen methoden, welche mit den Integrator der schnellen Skale parametriert ist. Dieser neue Ansatz erlaubt die Verallgemeinerung der Ausgangsmethode und vereinfacht etliche Schritte in der Herleitung der Ordnungsbedinungen. Zusätzlich hat die Verallgemeinerung auch den Vorteil, die Ordnungsbedingungen des Gesamtverfahrens und die Struktur des darunter liegenden Lösers der schnellen Zeitskale zu assoziieren. Wir untersuchen ebenfalls die lineare Stabilität der neuen Methoden. Aufgrund der Aufteilung in langsame und schnelle Terme gibt es viele verschiedene Modellprobleme. Wir leiten ein Modellproblem auf Basis eines vereinfachten hyperbolischer PDEs her. Auf Basis dieses Stabilitsproblems konstruieren wir die neuen Methoden und untersuchen ihre Effizienz anhand zweier nichtlineare Benchmarkprobleme. Analog zur Herleitung der Ordnungsbedingungen vereinheitlichen wir die Konstruktion der Stabilitätsfunktionen und heben im nachhinein die Unterschiede aufgrund des fast-scale integrators hervor. Gute numerische Methoden führen nicht nur zu einem kleinen Fehler, sondern haben auch ein großes Stabilitätsgebiet. Daher optimizieren wir die Methodenparameter im Hinblick auf die Größe des Stabilitätsgebiets. Unsere neuen Methoden besitzen sowohl reelle, als auch rationale Parameter. Die Lösung des gemischten ganzzahligen-reellen Optimierungsproblem vereinfachen wir durch die Auswahl einzelner rationaler Parameter. Dadurch erhalten wir allerdings einige tausend unabhängige Teilprobleme. Zum Abschluss analysieren wir die Effizienz der neuen Methoden anhand zweier nichtlinearer Benchmarkprobleme und vergleichen die Genauigkeit und Stabilität mit Referenzverfahren. / The expected temperatures and rainfall in the next days to hours is one of the most important information nowadays. This knowledge is not only of general interest. Disciplines like agriculture and forestry the knowledge of the rain is even more important for a time span of weeks to plan the harvest or protect the plants. Therefore, the possibility to forecast the weather reliably and fast is very important nowadays. The reliability of weather forecast, or more accurate the numerical weather forecast, depends on several factors. One factor is the complexity of atmosphere models. Whereas the first numerical experiments treat the atmosphere as dry ideal gas with one layer, recent models incorporate the humidity, clouds, precipitation and radiation. But every higher detail in the model come at higher costs for simulation. Hence the development of finer grained models also require more advanced numerical methods to solve them. The atmosphere models are in general a nonlinear hyperbolic set of partial differential equations (PDEs). In particular the models consist of several waves, traveling with different speeds with nearly no damping. Roughly speaking these varying velocities lead to the multiscale nature of the atmosphere models and a suitable numerical method should respect the different time scales. The development and analysis of multirate methods for hyperbolic systems remains a challenging problem. Examples for class of hyperbolic systems of PDEs range from the scalar and linear advection equation, the wave equation to nonlinear systems like the shallow water equations or the (inviscid) Euler equations, which are the basis for the atmosphere models. The hyperbolic PDEs often have an additive split structure, which in turn account for the different time scales. We assume a suitable, often finite volume, discretization in space. Hence we retain the additive splitting from the continuous problem in the semi-discretized ordinary differential equation (ODE). Hence we develop a new numerical method which accounts for the additive split structure and the multiscale nature. The development of splitting methods is challenging in the analysis of the order conditions and the stability criteria. In particular the interaction between the fast and slow scales render the order conditions often complicated and unstructured. Furthermore every multiscale approach combines the scales in a different way, which is why there is no unified order condition theory. With these challenges in mind we derive the order conditions in a classical way by differentiation of the numerical method. The splitting in a fast and a slow right hand side leads to several combinations of elementary differentials. And every differential has different non-standard coefficients, without any structure between these combinations. This loss in structure renders the numerical solutions of the order conditions quite complicated, and the analytical solutions are only possible in rare cases. We develop a new class of multirate methods, which is parameterized by the fast scale solver. That new approach allows for a better generalization and simplifies several steps by unification. Nevertheless this new type of generalization has the advantage to associate the order conditions of the complete (macro scale) method with the structure of the underlying (micro scale) integrator. The second challenge is the analysis of the (linear) stability of multirate methods. We also analyze the (linear) stability of the newly developed methods. Due to the splitting structure there are many different model problems possible. We deduce a model problem from a simplified system of hyperbolic PDEs. On top of these stability model problems we will construct the new methodss. In analogy to the analysis of the order conditions, we unify the construction of the stability functions and highlight the differences due to the different fast scale integrators afterwards. A good method does not only lead to low errors, but also has a large stability area. Hence we optimize the method parameters with respect to the stability area. In our case, the parameter set contains rational and real parameters. We circumvent the solution of a mixed-integer optimization problem by considering only some rational parameters and optimize for them independently. Nevertheless, we obtain several thousand sub problems. Finally we consider two nonlinear benchmark problems. With these problems we analyze the accuracy and stability again and compare the efficiency with two reference multiscale methods.

We will compare two different forecasting models with the forecasting model that was used in March 2014 by The Swedish Social Insurance Agency ("Försäkringskassan" in Swedish or "FK") in this degree project. The models are used for forecasting the number of cases. The two models that will be compared with the model used by FK are the Seasonal Exponential Smoothing model (SES) and Auto-Regressive Integrated Moving Average (ARIMA) model. The models will be used to predict case volumes for two types of benefits: General Child Allowance “Barnbidrag” or (BB_ABB), and Pregnancy Benefit “Graviditetspenning” (GP_ANS). The results compare the forecast errors at the short time horizon (22) months and at the long-time horizon (70) months for the different types of models. Forecast error is the difference between the actual and the forecast value of case numbers received every month. The ARIMA model used in this degree project for GP_ANS had forecast errors on short and long horizons that are lower than the forecasting model that was used by FK in March 2014. However, the absolute forecast error is lower in the actual used model than in the ARIMA and SES models for pregnancy benefit cases. The results also show that for BB_ABB the forecast errors were large in all models, but it was the lowest in the actual used model (even the absolute forecast error). This shows that random error due to laws, rules, and community changes is almost impossible to predict. Therefore, it is not feasible to predict the time series with tested models in the long-term. However, that mainly depends on what FK considers as accepted forecast errors and how those forecasts will be used. It is important to mention that the implementation of ARIMA differs across different software. The best model in the used software in this degree project SAS (Statistical Analysis System) is not necessarily the best in other software.

Sizing renewable energy power plants with storage devices needs new resource assessment. Global amount of energy available has to be replaced by time series to depict the resource as a function of time. This paper introduces methodology to generate time series for wind speed and solar irradiance with a granularity between 10minutes and 1seconde. Ground measurements and macro-date from satellite imagery are analyzed and processed to obtain long-term site-specific time series. Because renewable energy forecasting is a growing concern, a second part of the work presents how to modify previously generated profiles in order to obtain forecasts with an expected error.

Wind power generation does, on the one hand, contribute to a less polluting and more sustainable electric power generation mix. On the other hand, the uncertainty and the variability of the power output do challenge the operation of the power system: hourly variations in wind power generation are hardly predictable in a precise way. To decrease the need for balancing power, it might be beneficial from the overall system-perspective to subject power generating companies to stricter balancing incentives/rules. The way the market is designed has become crucial to exploit the existing flexibility in the power system and to increase the efficiency in its operation: inappropriate market designs can counteract all technical achievements. The work conducted for this thesis is embedded in a project on wind power integration and electricity market design following the aim to develop a simulation tool to analyse the consequences of changes in specific market rules. This thesis analyses wind power variations and forecast errors in the Swedish power system and explores the question whether internal ex-ante self-balancing can efficiently reduce the need for balancing power. Applying internal ex-ante self-balancing, every power generating company re-schedules its own power plants in order to balance its commitments towards other market actors with its newest production forecast. This is done shortly before the hour of delivery. To assess the value of this self-balancing, possible trading and scheduling decisions for power generating companies are modelled based on a hydro-thermal generation portfolio within the framework of the Nordic electricity market design. The model is based on a sequence of mixed-integer linear optimisation problems for the clearing of the different sub-markets. Both the data and the model have an hourly time resolution. In a case study, the model is applied on a simplified test-system. The need of real-time balancing by the transmission system operator, the total variable generation cost of the system, as well as the extent to which the power generating companies re-scheduled their production are then used as indicators to evaluate self-balancing. / <p>QC 20121017</p> / Short-term hydro power planning in power systems with large amounts of wind power / Elektra 36141: Korttidsplanering av vatten-värmekraftsystem vid stora mängder vindkraft: System-perspektivet

<p>NR 20140805</p>

With the ever-pressing threat of a climate crisis, the EU has decided to become the first climate-neutral continent by 2050. This in turn will require the road transportation sector to make a transition from fossil dependent to fossil-free vehicles. Sweden has the objective to become net positive in GHG emissions by 2045. To be on track to reach this goal, the GHG emissions of the domestic transport sector must be reduced by 70% by 2030 compared to 2017’s levels. Electric vehicles (EVs) are leading the way in the transition to fossil-free vehicles. To further springboard the diffusion of EVs, the development of a fully functional EV charging network is required. In order to assist the transition to electric vehicles, this report aims to analyse the development of the public fast charging infrastructure in Norrland and Svealand from now to 2030. Additionally, identify geographical areas where an expansion of the public EV fast charging network is needed to cover the future demand of electrified passenger cars. However, there are two major hurdles in building a fast charging network with full coverage. The first is the high monthly costs of providing fast charging which needs a certain utilisation rate to cover the expenses. The second hurdle is the difficulty to receive a grid connection, in certain areas, at the required power output to be able to provide EV fast charging. Therefore, a semi-mobile battery solution used for EV charging is analysed through a business model perspective. The semi-mobile battery solution requires a lower grid connection hence it could be possible to implement public EV fast charging at a lower monthly cost and to develop the public EV fast charging network in otherwise technical difficult areas. A mixed-method approach including both quantitative and qualitative elements was utilised. Primarily, a study of 10 interviews with respondents from a range of different fields connected to EV charging and batteries was performed in combination with a literature review and document analysis. In addition, existing traffic flow data and data of fast-charging infrastructure, were converged via ArcGIS Pro to illustrate the coverage of the fast charging network. Furthermore, projections of the development of the EV fleet were used in order to forecast the flow of EVs in Norrland and Svealand by 2030. Based on these forecasts the future demand of public EV fast charging was analysed. Resulting in a map showing areas of interest, where there will arise a need to expand the charging infrastructure. These areas are Umeå to Piteå, Lycksele with proximity, Bollnäs to Ljusdal and Leksand to Älvdalen. Additionally, the exiting public fast charging infrastructure was identified to require expansion of existing charging stations due to the increased traffic flow of EVs by 2030. The upgrade of existing stations was further assessed to be required to meet both a permanent and seasonal demand, hence making semi-mobile battery supported charging an attractive solution. Furthermore, the design of a semi-mobile battery supporting public EV fast charging was identified to be influenced by situational aspects and that the location-specific conditions were vital in determining profitability for a specific case. For example, the power output in the EV chargers should be adapted to the specifications of the geographical location and the customer segment identified. The energy storage capacity of the battery should also be designed based on the conditions of the location. A connection to the electricity grid exceeding 0.1 MW was also important since it enables the semi-mobile battery to provide additional services to the electricity grid and hence increase revenue streams. Furthermore, FCR-D Up was determined to be the most suitable complementary service to integrate into the system. One major challenge for the semi-mobile battery, based on a business model perspective, is the high costs for semi-mobile batteries and EV fast charging station hardware. However, these costs are projected to continue to decrease and consequently, improve the opportunities for semi-mobile lithium-ion batteries.

Den här studien utvärderar potentialen i söktermsdata från Google som ledande indikator för priser på bostadsmarknaden i Stockholm. Det prediktiva innehållet i söktermsdata från Google Trends jämförs mot en mer klassisk prognosmodell byggd på makroekonomiska variabler. Genom att mäta avvikelsen i en pseudo-prognos redovisas respektive datakällas förmåga till riktiga prognoser. Den huvudsakliga slutsatsen är att det finns resultat som styrker tesen om prediktivt innehåll i Googledata, framförallt för prognoser med horisonter upp till sex månader. Genom att använda Googledata skapas prognoser som har en mindre avvikelse från den faktiska tidsserien är vad modellen byggd på makroekonomiska variabler kan leverera. Resultatet visar på användbarheten i söktermsdata från Google som ledande indikator för priser på bostadsmarknaden i Stockholm. / This study evaluates the potential in using Google search term data as a leading indicator of prices on the real estate market in Stockholm. The predictive content of the search term data from Google Trends is contrasted against a more classic forecasting model using macroeconomic variables. The ability of each data source to generate powerful forecasts is demonstrated by measuring the deviation in a pseudo-forecast. The main finding is that the results support the hypothesis on predictive content in Google data, mainly forecasts with up to six months’ horizon. By using Google data, forecasts can be made with less deviation from the actual time series than forecasts built on macroeconomic variables. The results point to the usability of search term data from Google as a leading indicator for prices on the real estate market in Stockholm.

Abstract Title: How strategic decisions are handled in the sales and business planning process (S&amp;OP): A qualitative case study that examines steps 1 and 2 in the sales and business planning process, conducted at IKEA. Authors: Alma Nyroos, Lovisa Lim, Maja Bjuringer &amp; Tilly Anderfors Supervisor: Petra Andersson, LNU Examiner: Hana Hulthén, LNU Background: Planning for today's supply chains has become an increasingly complex challenge. This is because global competition is increasing, at the same time as technology is constantly changing. In order to be able to compete in the market, it is important to make the planning of these chains more effective. One way to plan more efficiently is by using sales and operations planning (S&amp;OP). S&amp;OP's three important flows that are coordinated are materials, finances and information. Today, IKEA feels that they must use some temporary solutions to handle information that comes late in the process and changes the need for different resources. Research question:  1. What are the shortcomings in IKEA's S&amp;OP process with delimitation to step one (data gathering) and two (demand planning)? 2. What are the causes of these shortcomings and how could these shortcomings be rectified? Purpose: The purpose of the study is to identify shortcomings in step one and two in IKEA's S&amp;OP process. This is to be able to contribute with improvement measures in the process. Implementation: This is a case study on IKEA. The data that has been collected in this study are a combination of primary and secondary data.  Conclusion: In this study, it emerges that integration and coordination are two important aspects of the S&amp;OP work. It is addressed by most article writers and has also been linked to IKEA's shortcomings. This is linked to the first two steps in the S&amp;OP process. In the investigative organization, gaps were discovered both between internal units and between strategic and operational decisions. For the identified gaps, it is proposed to focus on coordinating the processes in such a way that more people are integrated. Both in terms of integration between different levels (strategic, tactical and operational) and between different units working at the same level. The study also shows that decisions must be integrated into processes in a better way, through better planned information sharing. Keywords: S&amp;OP, demand, forecast, strategic, tactic, operational, integration, coordination.

På uppdrag av JAADAB AB har en undersökning huruvida prognosstyrning kan användas för att effektivt reglera värme i en byggnad samt spara energi och ge jämnare innetemperatur genom att använda SMHIs öppna API. I uppdraget ingick även att skapa en modell för att kunna implementera detta i en befintlig byggnad med okända där exakt kännedom om byggandens konstruktion och egenskaper saknas.   Arbetet inleddes med en teoristudie gällande byggnadens värmeöverföring samt hur vädret påverkar detta samt där det framgår att byggnaden kan tillgodogöra sig tillförd energi från solinstrålning samt att vind leder till ökade förluster via transmission, ventilation samt läckage.  En studie gjordes även gällande prognosstyrning som ledde fram till en väderkompenserad ekvivalent temperatur.   Modellen skapades sedan först teoretiskt innan den programmerades med ett koncept där byggnaden beskrivs via parametrar gällande utformning och material där bedömningar kan göras i de fall där exakt kunskap saknas. Modellen använde sedan dessa parametrar och SMHIs API för beräkningar gällande byggandens värmebalans under de nästkommande två dygnen och ta fram en ekvivalent temperatur som ersätter utetemperaturen som ingående temperatur till styrsystemet. Beräkningar gällande vind finns förberedda men är inte inkluderade då inget tillräckligt pålitligt samband mellan vindhastighet och förluster kunde fastställas innan simuleringsstart.    Modellen simulerades för en lätt och en tung byggnadskonstruktion via en DUC där utetemperaturen given av SMHI samt den ekvivalenta temperaturen loggades under fyra dygn.   Resultatet av simuleringen visade att medeltemperaturen var högre i båda fallen för den ekvivalenta temperaturen.  Gällande den tunga byggnadskonstruktionen var topptemperaturen lägre och bottentemperaturen högre för den ekvivalenta temperaturen. Gällande den lätta byggnadskonstruktionen var både topp och bottentemperaturen lägre för den ekvivalenta temperaturen. Arbetet visar tecken på att energibesparingar kan göras men kan inte fastställa att detta kan göras på lång sikt på grund av den korta testperioden som medför att ett begränsat antal förhållanden testats.   Förbättringsförslag finns lämnade via mera komplexa beräkningar gällande byggnadens värmeöverföring och påverkan av närmiljö samt flera och längre simuleringar. Förslag på framtida arbeten har lämnats gällande slutförande av vindberäkningar, ytterligare simuleringar, test på verklig byggnad och adderandet av en självlärande loop. / On behalf of JAADAB AB, a study has been conducted on whether forecast control can be used to effectively regulate heat in a building to save energy and provide a more even indoor temperature by using SMHI's open API. The assignment also included creating a model to be able to implement this in an existing building where details regarding the construction and properties of the building are unknown. The work began with a theoretical study regarding the building's heat transfer and how the weather affects the heat transfer where it appears that the building can utilize the supplied energy from solar radiation and that wind leads to increased losses via transmission, ventilation and leakage. A study was also done regarding forecast control which led to a weather-compensated equivalent temperature. The model was then first created theoretically before it was programmed with a concept where the building is described via parameters regarding design and materials where assessments can be made in cases where exact knowledge of the values is lacking. The model then used the submitted parameters and SMHI's API for calculations regarding the construction's heat balance during the next two days to produce an equivalent temperature that replaces the outdoor temperature as the input temperature to the control system. Calculations regarding wind are prepared but are not included as no sufficiently reliable connection between wind speed and losses could be established before the start of the simulation. The model was simulated for a light and a heavy building construction via the use of a DUC where the outdoor temperature was given by SMHI and the equivalent temperature were logged for four days. The result of the simulation showed that the average temperature was higher in both cases for the equivalent temperature. Regarding the heavy building construction, the highest temperature was lower and the bottom temperature higher for the equivalent temperature. Regarding the lightweight building construction, both the top and bottom temperatures were lower for the equivalent temperature. The work shows signs that energy savings can be made but it cannot be established that this can be done in the long term due to the short test period which means that a limited number of conditions have been tested. Suggestions for improvement have been submitted via more complex calculations regarding the building's heat transfer and impact on the local environment around the building as well as several further simulations with over more extended periods of time. Suggestions for future work have been submitted regarding the completion of wind calculations, additional simulations, tests on real building and the addition of a self-learning loop.

Die Vorteile der Kernschätzung gegenüber dem Abzählen von Ereignissen in Zeitintervallen werden dargestellt. Für das beiden Methoden gemeinsame Glättungsproblem gestattet die Kreuzvalidierung eine Lösung. Für die Hochwasserereignisse der Oder im Zeitraum 1350 bis 1850 wird eine Abnahme der Häufigkeit nach ca. 1675 gefunden; weitergehende Aussagen bedingen eine Homogenisierung der Daten. Die dargestellte Methodik wird gegenwärtig in das Computerprogramm XTREND implementiert. / The advantages of kernel estimation over counting of events within time intervals are shown. Cross validation offers a solution for the smoothing problem which is common to both methods. As regards ooding events of the river Oder in 1350 to 1850, a decrease in the frequency after about 1675 is found. More detailed results demand homogenized data. The method is currently being implemented into the computer program XTREND.