14 research outputs found
Journal Staff
There is an international tendency toward increased demand for both cost-efficiency and high reliability of power distribution systems. To meet these demands, asset management methods, including reliability analyses, have been developed. These reliability analyses often utilize only mean values and hence do not take into consideration the consequences of severe events. This paper proposes a framework for more detailed quantitative risk analysis methods. The aim is to allocate resources more cost-effectively. The suggested framework is exemplified and evaluated by implementing it within the analyses of a real power distribution system. The main concept is to divide comprehensive projects into minor analyses and then in a final step compile the results. The proposed analysis framework can be used independently or combined with earlier proposed vulnerability methods. The latter provides a two-dimensional analysis framework. It is shown that totally different investment alternatives could be preferred depending on whether a traditional analysis method using average values is employed compared with the proposed analysis framework, which also considers severe system states. This demonstrates the risks involved in using average values and the strength of the proposed method. Furthermore, it is shown that already available information can be used for improved asset management decision support. In addition, the performed case study gives combined reliability and weather statistics useful as reference material.QC 20150123</p
Evaluating the detail level of reliability analyses used in the investment planning at Fortum Distribution AB
This master thesis project is a cooperation between Fortum Distribution AB and The Royal Institute of Technology (KTH). When maintaining and operating a power distribution system, which is the task of Fortum Distribution AB, the aim is to always be able to deliver electric energy to the customers. A 100% reliability is however not a realistic goal since too high reliability would cost too much. The net planners at Fortum have to choose the most cost effective investments. Due to the complexity of the power system, grid analyses are expensive and simplifications have to be made. In this master thesis it is examined if Fortum Distribution ABâs methods for prioritizing between different reliability investments for the rural power distribution system are detailed enough to give the same result as more complex methods. This is done by creating theoretical models of two 11 kV lines out of two different substations in a rural part of Fortumâs grid. The fault management process at Fortum Distribution AB is thoroughly described and implemented in the theoretical models of the two case lines. The time it takes to perform specific tasks in the fault management are listed for future reference. A couple of investments for better reliability are applied to the case lines. The effect on reliability and cost efficiency of different investments allow for the investments to be prioritized after which are better to implement. One of the case lines is in an area where reliability investments have already been performed. This line is chosen because the results from the analysis then can be compared to the real investments. To test and apply the result the other case study is performed on an area that has not yet been renovated. For this case line cost-efficient investments are recommended. The conclusion of the analyses is that the detail level of the analyses made by Fortum Distribution AB most likely are sufficient for todayâs grid. However, because of the ongoing project to weather-secure the grid, changing overhead lines for underground cables is the number one priority. The analysis in this thesis could have reflected the effect of extreme weather better, but even so, the result shows such a significantly lower cost-efficiency for investing in cables that it might be favorable for Fortum Distribution AB to review the benefits of changing overhead lines for underground cables. In some cases other investments might be more beneficial.Denna svenska sammanfattning av examensarbetet riktar sig kanske frĂ€mst till personer pĂ„ Fortum eller den som annars har en inblick i arbetet pĂ„ ett elnĂ€tsföretag. Det hĂ€r examensarbetet Ă€r ett samarbete mellan Fortum Distribution AB och KTH. MĂ„let med examensarbetet Ă€r att undersöka om Fortum Distibution ABâs metoder för att prioritera mellan olika investeringar för bĂ€ttre tillförlitlighet pĂ„ lokala landsbygdsnĂ€t ger samma resultat som mer komplexa metoder. Projektet har genomförts genom att göra teoretiska modeller av tvĂ„ linjer i Fortums nĂ€t. Den ena, 102A Lesjöfors, Ă€r en linje dĂ€r omfattande upprustningar redan genomförts. DĂ€r görs modellen av hur linjen sĂ„g ut innan den byggdes om för att sedan kunna jĂ€mföras mot verkligheten. Den andra linjen, 020E Charlottenberg, Ă€r en linje som Ă€r i behov av renovering. För denna linje kommer rekommendationer baserade pĂ„ resultatet av denna studie att ges. Indata till modellerna Ă€r felintensiteter för ett par olika komponenter och Ă„tgĂ€rdstiderna för att Ă„terstĂ€lla funktionen dĂ„ ett avbrott intrĂ€ffat. Komponenterna som beaktas Ă€r luftledningar, kablar, brytare, frĂ„nskiljare och lĂ„gspĂ€nningskomponenter (vars felintensitet aggregeras till en). Felintensiteterna uppskattas frĂ„n historiska data över avbrott i omrĂ„det. Ett mĂ„l Ă€r att anvĂ€nda sĂ„ lokala avbrottsdata som möjligt för att spegla de lokala variationerna av hur ofta fel intrĂ€ffar. Ă
tgĂ€rdstiderna har uppskattats genom intervjuer med nĂ€tplanerare, driftoperatörer och montörer pĂ„ Fortum och Infratek. Infratek Ă€r ett bolag som bygger och underhĂ„ller infrastruktur. Linjen delas upp i olika segment efter var frĂ„nskiljarna sitter placerade, och kunderna som bor mellan samma tvĂ„ frĂ„nskiljare slĂ„s samman till en s.k. lastpunkt. För varje lastpunkt berĂ€knas felintensitet och Ă„tgĂ€rdstid för olika typer av felfall, som t.e.x. fel pĂ„ luftledning. För varje lastpunkt berĂ€knas det total antalet avbrott och den totala tiden dĂ„ lastpunkten varit utan ström. Dessa multipliceras sedan med antalet kunder vid varje lastpunkt, och det totala antalet kundavbrott och kundavbrottstimmar anvĂ€nds sedan för att berĂ€kna SAIFI och SAIDI (se definition i avsnitt 2.1). Ett antal olika investeringsscenarier undersöks för linjen. De olika investeringsalternativen Ă€r bĂ„de vanliga typer av investeringar, sĂ„ som kablifiering, men Ă€ven lite nyare investeringar undersöks. Att sĂ€nka spĂ€nningen pĂ„ en mindre radiell ledning till 1 kV och att installera en linjebrytare Ă€r exempel pĂ„ sĂ„dana investeringar som Ă€nnu inte har anvĂ€ndts speciellt mycket. Utöver dessa investeringar undersöktes Ă€ven alternativet att uppgradera de manuella frĂ„nskiljarna till automatiska och att lĂ€gga till en möjlighet till sekundĂ€r matning. Kablifiering var den investering som tidigare har utförts pĂ„ den verkliga Lesjöforslinjen. En modell gjordes dĂ€rför Ă€ven av Lesjöforslinjen som den ser ut idag. PĂ„ sĂ„ vis kunde den i verkligheten genomförda investeringen jĂ€mföras mot de teoretiska investeringarna. Ăvriga investeringar berĂ€knades genom att modifiera de befintliga modellerna för linjerna. För investeringarna berĂ€knas nya SAIFI och SAIDI, samt minskningen av kundavbrottsminuter. En LCC-analys görs av kostnader och inkomster frĂ„n investeringarna under dess livslĂ€ngd, som antas vara 40 Ă„r. I den totala kostnaden ingĂ„r investeringskostnad, underhĂ„llskostnader, kundavbrottsersĂ€ttningar för lĂ„nga avbrott och förĂ€ndringar pĂ„ intĂ€ktsramen via regleringen. FörĂ€ndringarna pĂ„ intĂ€ktsramen beror dels av en kvalitetsjustering baserat pĂ„ hur mycket SAIFI och SAIDI har sĂ€nkts, dels pĂ„ om kapitalbasen Ă€ndras genom investeringen. Med de totala kostnaderna och sĂ€nkningen av kundavbrottsminuter tas nyckeltalen SEK/kundavbrottsminut och SEK/isolerad km ledning fram. Dessa nyckeltal anvĂ€nds av Fortum i investeringsplaneringen. Investeringarna sorteras sedan efter kostnadseffektivitet. Slutsatserna av projektet kan sammanfattas i ett antal punker: VĂ€dersĂ€kring har högsta prioritet inom investeringsplaneringen pĂ„ Fortum idag. Analyserna i detta examensarbete kunde ha speglat effekten av extremvĂ€der starkare. Trots detta Ă€r kostnadseffektiviteten för kablifiering sĂ„ signifikant mycket lĂ€gre Ă€n för de andra investeringarna att det kan vara vĂ€rt för Fortum att rĂ€kna pĂ„ vinsterna med att kablifiera för att se om det kanske finns situationer dĂ€r andra investeringar hade varit lönsammare. I Fortums analyser görs flera förenklingar, bl.a. att kablar Ă€r felfria. BerĂ€kningarna i denna rapport har visat att kablar har mycket liten effekt pĂ„ systemets tillförlitlighet och att denna förenkling nog kan anses vara acceptabel. Detta kan dock komma att förĂ€ndras. Om kablifieringen av nĂ€tet fortsĂ€tter kommer en större och större del av det bestĂ„ av kabel. Detta gör att kablarnas felintensitet fĂ„r en allt större procentuell betydelse. Det kan vara vĂ€rt att fundera pĂ„ hur detaljerade berĂ€kningar man bör ha pĂ„ sikt om luftledningsnĂ€ten byggs bort. Regleringen har en mycket stor pĂ„verkan pĂ„ hur kostnadseffektiva investeringar blir. Det Ă€r dĂ€rför fördelaktigt att ta med regleringens inverkan i berĂ€kningarna för att kunna avgöra vilken investering som ger bĂ€st resultat. Regleringen av elnĂ€tsföretagen har dock, och kan komma att, skifta och det Ă€r inte sĂ€kert att de regler som gĂ€ller idag Ă€ven gĂ€ller nĂ€sta reglerperiod. DĂ€rför kan det Ă€ven vara bra att vĂ€lja investeringar vars lönsamhet inte rasar om en förĂ€ndring av regleringen skulle ske, med tanke pĂ„ att livslĂ€ngden pĂ„ investeringen berĂ€knas vara 40 Ă„r
Adjusting brand image to culture through advertising : A study of Swedish companies established in Japan
Abstract Background Companies today are becoming more and more internationalized. In their home countries they have already established strong brand recognition and a strong image. This image is in turn visible in their advertising. As Swedish companies travel abroad some aspects have to be adapted to the new culture. A culture viewed as very different from the West is the Japanese culture. Swedish companies entering this culture must adapt in many ways in order to reach the Japanese consumers. Some companies with well established images might not be willing to make some of the adaptations. Purpose The purpose with this thesis is to establish if Swedish companies who have established themselves in Japan have to change their image through advertising in order to match the culture. Method This gathering of empirical data in this thesis was performed through a qualitative method. Six companies were contacted for phone interviews. Five of these companies were Swedish companies established in Japan and one of them was a Japanese company established in Sweden. All interviews were conducted with people in managerial positions. As a compari-son between Sweden and Japan, ads for each company were also used in order to make our conclusions. Results This thesis will show that most likely, Swedish companies must to some extent adjust their brand images to fit the Japanese culture. These adaptations are viewed mainly through their advertising efforts though also through their service and product improvements
Optimal Multi-Commodity Network Flow of Autonomous Vehicles in Urban Traffic
The focus of this thesis was to find, visualize and analyze the optimal flow of autonomous vehicles in urban traffic with respect to fuel consumption using linear optimization. Two different formulations based on multi-commodity network flow were implemented which resulted in a static and a dynamic model of the traffic. The static model was applied to Kungsholmen, an urban district in central Stockholm, Sweden, while the dynamic model was considered on a small-scale. These models led to large linear programs which were solved by applying different algorithms to the problems in various software. The results suggested that the developed models were adequate approximations of the urban traffic flow for the chosen parameter set-ups. It was concluded that the traffic in a system of autonomous vehicles may be optimally planned using similar models as formulated in this study
Undercover Marketing : The method which lies beneath
Background: A coming of age of a generation named Generation Y, which holds negative views on commercial messages, has resulted in the need of special marketing methods which are known to be more alternative. Guerrilla Marketing, being such a method holds beneath it Undercover Marketing which is another method and has the potential of reaching this generation. Purpose: Our purpose is firstly to define a theoretical placement of Undercover Marketing, secondly to define the theoretical views on ethics regarding the mentioned term and thirdly to see if there is a future, a will, and knowledge for its usage within the Swedish community of marketing practitioners. Method: The research for this thesis is done in a qualitative method through a series of interviews with four advertising firms and one freelance artdirector. The interviews were compared to each other and to the frame of reference during the analysis in order to create a more complete picture. Results: In this thesis we have seen that there is a future in the use of Undercover Marketing as it can prove to be the only method able to reach Gen Y. However it must follow certain rules to succeed and companies must take certain factors into consideration prior to attempting a marketing campaign including this particular method
DjupinlÀrningsbaserade regulariserare för rekonstruktion inom volymtomografi
Cone Beam Computed Tomography is a technology to visualize the 3D interior anatomy of a patient. It is important for image-guided radiation therapy in cancer treatment. During a scan, iterative methods are often used for the image reconstruction step. A key challenge is the ill-posedness of the resulting inversion problem, causing the images to become noisy. To combat this, regularizers can be introduced, which help stabilize the problem. This thesis focuses on Adversarial Convex Regularization that with deep learning regularize the scans according to a target image quality. It can be interpreted in a Bayesian setting by letting the regularizer be the prior, approximating the likelihood with the measurement error, and obtaining the patient image through the maximum-a-posteriori estimate. Adversarial Convex Regularization has previously shown promising results in regular Computed Tomography, and this study aims to investigate its potential in Cone Beam Computed Tomography. Three different learned regularization methods have been developed, all based on Convolutional Neural Network architectures. One model is based on three-dimensional convolutional layers, while the remaining two rely on 2D layers. These two are in a later stage crafted to be applicable to 3D reconstruction by either stacking a 2D model or by averaging 2D models trained in three orthogonal planes. All neural networks are trained on simulated male pelvis data provided by Elekta. The 3D convolutional neural network model has proven to be heavily memory-consuming, while not performing better than current reconstruction methods with respect to image quality. The two architectures based on merging multiple 2D neural network gradients for 3D reconstruction are novel contributions that avoid memory issues. These two models outperform current methods in terms of multiple image quality metrics, such as Peak Signal-to-Noise Ratio and Structural Similarity Index Measure, and they also generalize well for real Cone Beam Computed Tomography data. Additionally, the architecture based on a weighted average of 2D neural networks is able to capture spatial interactions to a larger extent and is adjustable to favor the plane that best shows the field of interest, a possibly desirable feature in medical practice.Volymtomografi kan anvÀndas inom cancerbehandling för att skapa bilder av patientens inre anatomi i 3D som sedan anvÀnds vid strÄldosplanering. Under den rekonstruerande fasen i en skanning anvÀnds ofta iterativa metoder. En utmaning Àr att det resulterande inversionsproblemet Àr illa stÀllt, vilket leder till att bilderna blir brusiga. För att motverka detta kan regularisering introduceras som bidrar till att stabilisera problemet. Fokus för denna uppsats Àr Adversarial Convex Regularization som baserat pÄ djupinlÀrning regulariserar bilderna enligt en mÄlbildskvalitet. Detta kan Àven tolkas ur ett Bayesianskt perspektiv genom att betrakta regulariseraren som apriorifördelningen, approximera likelihoodfördelningen med mÀtfelet samt erhÄlla patientbilden genom maximum-a-posteriori-skattningen. Adversarial Convex Regularization har tidigare visat lovande resultat för data frÄn Datortomografi och syftet med denna uppsats Àr att undersöka dess potential för Volymtomografi. Tre olika inlÀrda regulariseringsmetoder har utvecklats med hjÀlp av faltningsnÀtverk. En av modellerna bygger pÄ faltning av tredimensionella lager, medan de ÄterstÄende tvÄ Àr baserade pÄ 2D-lager. Dessa tvÄ sammanförs i ett senare skede för att kunna appliceras vid 3D-rekonstruktion, antingen genom att stapla 2D modeller eller genom att berÀkna ett viktat medelvÀrde av tre 2D-modeller som trÀnats i tre ortogonala plan. Samtliga modeller Àr trÀnade pÄ simulerad manlig bÀckendata frÄn Elekta. 3D-faltningsnÀtverket har visat sig vara minneskrÀvande samtidigt som det inte presterar bÀttre Àn nuvarande rekonstruktionsmetoder med avseende pÄ bildkvalitet. De andra tvÄ metoderna som bygger pÄ att stapla flera gradienter av 2D-nÀtverk vid 3D-rekonstruktion Àr ett nytt vetenskapligt bidrag och undviker minnesproblemen. Dessa tvÄ modeller övertrÀffar nuvarande metoder gÀllande flera bildkvalitetsmÄtt och generaliserar Àven vÀl för data frÄn verklig Volymtomografi. Dessutom lyckas modellen som bygger pÄ ett viktat medelvÀrde av 2D-nÀtverk i större utstrÀckning fÄnga spatiala interaktioner. Den kan Àven anpassas till att gynna det plan som bÀst visar intresseomrÄdet i kroppen, vilket möjligtvis Àr en önskvÀrd egenskap i medicinska sammanhang
DjupinlÀrningsbaserade regulariserare för rekonstruktion inom volymtomografi
Cone Beam Computed Tomography is a technology to visualize the 3D interior anatomy of a patient. It is important for image-guided radiation therapy in cancer treatment. During a scan, iterative methods are often used for the image reconstruction step. A key challenge is the ill-posedness of the resulting inversion problem, causing the images to become noisy. To combat this, regularizers can be introduced, which help stabilize the problem. This thesis focuses on Adversarial Convex Regularization that with deep learning regularize the scans according to a target image quality. It can be interpreted in a Bayesian setting by letting the regularizer be the prior, approximating the likelihood with the measurement error, and obtaining the patient image through the maximum-a-posteriori estimate. Adversarial Convex Regularization has previously shown promising results in regular Computed Tomography, and this study aims to investigate its potential in Cone Beam Computed Tomography. Three different learned regularization methods have been developed, all based on Convolutional Neural Network architectures. One model is based on three-dimensional convolutional layers, while the remaining two rely on 2D layers. These two are in a later stage crafted to be applicable to 3D reconstruction by either stacking a 2D model or by averaging 2D models trained in three orthogonal planes. All neural networks are trained on simulated male pelvis data provided by Elekta. The 3D convolutional neural network model has proven to be heavily memory-consuming, while not performing better than current reconstruction methods with respect to image quality. The two architectures based on merging multiple 2D neural network gradients for 3D reconstruction are novel contributions that avoid memory issues. These two models outperform current methods in terms of multiple image quality metrics, such as Peak Signal-to-Noise Ratio and Structural Similarity Index Measure, and they also generalize well for real Cone Beam Computed Tomography data. Additionally, the architecture based on a weighted average of 2D neural networks is able to capture spatial interactions to a larger extent and is adjustable to favor the plane that best shows the field of interest, a possibly desirable feature in medical practice.Volymtomografi kan anvÀndas inom cancerbehandling för att skapa bilder av patientens inre anatomi i 3D som sedan anvÀnds vid strÄldosplanering. Under den rekonstruerande fasen i en skanning anvÀnds ofta iterativa metoder. En utmaning Àr att det resulterande inversionsproblemet Àr illa stÀllt, vilket leder till att bilderna blir brusiga. För att motverka detta kan regularisering introduceras som bidrar till att stabilisera problemet. Fokus för denna uppsats Àr Adversarial Convex Regularization som baserat pÄ djupinlÀrning regulariserar bilderna enligt en mÄlbildskvalitet. Detta kan Àven tolkas ur ett Bayesianskt perspektiv genom att betrakta regulariseraren som apriorifördelningen, approximera likelihoodfördelningen med mÀtfelet samt erhÄlla patientbilden genom maximum-a-posteriori-skattningen. Adversarial Convex Regularization har tidigare visat lovande resultat för data frÄn Datortomografi och syftet med denna uppsats Àr att undersöka dess potential för Volymtomografi. Tre olika inlÀrda regulariseringsmetoder har utvecklats med hjÀlp av faltningsnÀtverk. En av modellerna bygger pÄ faltning av tredimensionella lager, medan de ÄterstÄende tvÄ Àr baserade pÄ 2D-lager. Dessa tvÄ sammanförs i ett senare skede för att kunna appliceras vid 3D-rekonstruktion, antingen genom att stapla 2D modeller eller genom att berÀkna ett viktat medelvÀrde av tre 2D-modeller som trÀnats i tre ortogonala plan. Samtliga modeller Àr trÀnade pÄ simulerad manlig bÀckendata frÄn Elekta. 3D-faltningsnÀtverket har visat sig vara minneskrÀvande samtidigt som det inte presterar bÀttre Àn nuvarande rekonstruktionsmetoder med avseende pÄ bildkvalitet. De andra tvÄ metoderna som bygger pÄ att stapla flera gradienter av 2D-nÀtverk vid 3D-rekonstruktion Àr ett nytt vetenskapligt bidrag och undviker minnesproblemen. Dessa tvÄ modeller övertrÀffar nuvarande metoder gÀllande flera bildkvalitetsmÄtt och generaliserar Àven vÀl för data frÄn verklig Volymtomografi. Dessutom lyckas modellen som bygger pÄ ett viktat medelvÀrde av 2D-nÀtverk i större utstrÀckning fÄnga spatiala interaktioner. Den kan Àven anpassas till att gynna det plan som bÀst visar intresseomrÄdet i kroppen, vilket möjligtvis Àr en önskvÀrd egenskap i medicinska sammanhang
A Pre-Study Towards Investigating the Art of Choosing Right Level of Input Data
The international tendency towards quality regulation of power distribution tariffs, along with a generally increased pressure of cost efficiency with maintained high reliability, give incentives to introduce more advanced analysis methods within asset management and project planning. This paper proposes a method to compare existing analysis methods with other methods or improvements of current method without perform any sharp changes in the organization. The approach is to compare recently performed risk reducing investments, based on current analysis methods used by the company, and then perform a hypothetical investment planning process based on more comprehensive reliability analysis. This paper presents results from a pre-study of a collaborative project between the industry and the academy to highlight and investigate the art of choosing right detail level of input data used within reliability analysis of power distribution. The aim of the paper is also to: on one hand provide academic reference material from the ârealityâ, and on the other hand to inspire the industry to review their current analysis methods and if needed, implement improvements. QC 20120061
Fault Management at a Distribution System Operator
This paper describes the fault management at a distribution system operator (DSO) including all steps, from detection to restoration. Differences in this work depending on equipment available are compared such as remote versus manual disconnectors. Often, in reliability models of power distribution, a restoration time is assumed; sometimes divided into parts such as an identification time and a repair/switching time. The approach is to describe the actual work by interviewing several people working at a DSO. Furthermore results from a former study at the same DSO are summarized to provide a complete picture of the asset management at a DSO. The aim of this study is to provide a detailed description of actual work to use as reference when developing more comprehensive analysis methods. Another possible usage is to improve current asset management by e.g. identify potential improvements in working methods using existing equipments or to use as input to project planning. These kinds of studies decrease the gap between theoretical models and the reality of workers at DSOs, which probably is the most important contribution of this paper.QC 20130617</p
Shared calendar implementation in a company
Jebkura uzĆÄmuma veiksmÄ«gas darbÄ«bas pamatÄ ir lietderÄ«ga laika izmantoĆĄana, kuras realizÄĆĄanai nepiecieĆĄams veikt uzĆÄmuma darbu plÄnoĆĄanu. BieĆŸi vien uzĆÄmumos netiek nodroĆĄinÄta centralizÄta datu apmaiĆa starp darba devÄju un darbinieku un tas rada risku, ka noteiktie uzdevumi netiek veikti kvalitatÄ«vi un noteiktajÄ laikÄ. Lai risinÄtu ĆĄÄdas problÄmas, daudzu uzĆÄmumu vadÄ«tÄji spiesti meklÄt kvalificÄtus speciÄlistus ĆĄÄdas darbu plÄnoĆĄanas programmatĆ«ras izstrÄdei vai arÄ« iegÄdÄties kÄdus no komerciÄlajiem risinÄjumiem, visbieĆŸÄk abos no minÄtajiem variantiem uzĆÄmumu vadÄ«ba saskaras ar augstÄm izmaksÄm par programmatĆ«ras izstrÄdi, ievieĆĄanu un apkalpoĆĄanu, pilnÄ«bÄ izslÄdzot iespÄjas lietot kÄdu no bezmaksas risinÄjumiem.
DarbÄ tiks apskatÄ«ta risinÄjuma uzstÄdÄ«ĆĄana, ievieĆĄana, droĆĄÄ«ba, uzturÄĆĄana un atjauninÄĆĄana.Any company's success is based on effective use of time, which requires working by strictly detailed plan. Often companies do not provide a centralized data exchange between employers and employees, and it pose a risk that the tasks are not executed qualitative and on time. To solve such problems many companies are forced to search qualified professionals, to plan that kind of software or they need to buy expensive commercial solution. The companies exclude opportunities for using some of the free software.
The paper explores a solution to installation, implementation, security, maintenance and updating