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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1001

Monitoring the energy consumption in buildings in B2B sector

RIFAI, Nabil January 2016 (has links)
This report discusses the ambition of EDF, a French electricity provider, to offer new services to its customers. With the emergence of the smart grid that will be operational in 2020 in France, there are several opportunities that have to be taken. One of them is to be able to offer a suitable monitoring system to its customer. This study tried to emphasize the important aspects and features that are required in such a system. Several solutions that are currently being commercialized in France have been analyzed. A grading has been made according to the technical functionalities and the business models have been analyzed.  Recommendations for EDF have also been made in order to help the company to choose the right monitoring system.
1002

Miljonprogramhusens framtid ur energisynpunkt : Så ställer sig fastighetsägarna till omfattande renoveringar / The future of the Swedish Million Homes Programme from an energy perspective : How property owners react to extensive renovations

Adolfsson, Hanna, Jansson, Johanna January 2015 (has links)
Klimatförändringar i världen är ett faktum och för att hejda effekterna som utsläppen av växthusgaser orsakar måste samhället agera. Byggindustrin är en stor orsak till detta och det har lett till att energikrav upprättats med mål att minska klimatpåverkan. Flerbostadshusen som byggdes 1965-74, så kallade miljonprogramhus, är många och eftersom alla föråldrats i samma takt blir deras miljöbelastning stor.   Syftet med detta examensarbete är att undersöka hur fastighetsägare av miljonprogramhus kommer att agera på framtida renoveringar ur energisynpunkt. En förundersökning av relevant litteratur genomfördes för att få en ökad kunskap inom valt ämnesområde och lämpligt material till intervjuunderlaget.   Samtliga tillfrågade fastighetsägare arbetar med att energieffektivisera sitt bostadsbestånd och anser sig ha god ekonomi. Åtgärdsvalet baseras dock på huset skick och vilket avkastningskrav de arbetar efter. Fastighetsägarna ser sig uppnå målet om att minska sin energianvändning med 20 procent till år 2020 för sitt totala bostadsbestånd dock inte specifikt för deras miljonprogramhus. Detta beror på att fastighetsägarna har ett äldre bostadsbestånd som prioriteras först. För att nå visionen om en halvering av energianvändningen till år 2050 behöver majoriteten av fastighetsägarna utföra mer energieffektiviserande renoveringar. / Climate change in the world is a fact and to stop the effects that the greenhouse gas emissions causes requires the society to take action. The construction industry is a major cause of this and has led the government to establish energy requirements with the goal to reduce the carbon footprint. The large number of multi-apartment dwellings, the so called Million Homes Programme, built in 1965-74 causes severe environmental impact hence them aging at the same time.     The aim of this thesis is to, from an energy perspective, investigate how property owners of the Million Homes Programme will act on future renovations. A preliminary research of relevant literature was implemented to gain a better understanding in the chosen subject and appropriate material to perform the interviews.    All of the interviewed property owners are working on getting their houses more energy efficient and believe they have a good economy to carry through. However, the choice of action is based on the buildings condition and the required rate of return that the property owners are after. Further they are looking to achieve the goal of reducing their energy use by 20 percent by 2020 for their overall housing stock but not specifically for their Million Homes Programme. Great demands are made on the majority of the property owners to do more energy efficient renovations in order to reach the aim of a 50 percent energy use reduction by 2050.
1003

Behavior Related Energy Use in Single-Family Homes : A Study on residential houses in Sweden

Ghasemi, Milad January 2015 (has links)
Complete overview of energy use in a residential building is depends on many different factors. When analyzing proper and effective ways for energy reducing/conserving systems, often times only technological solutions for households appliances are considered. Human behavior has been shown to be an important factor affecting the overall energy use in the household. Many aspects of energy use are directly connected to user behavior and are affected by how the user utilizes available systems. This paper focuses on describing the mean influencing causes of human environmental psychology based on study on a Swedish suburb community, called Fårdala. User behaviors and actions affecting residential energy use are analyzed and presented in form of eleven (11) abstract triggers to households energy use. Finally an energy monitoring system based on the findings are purposed. What is found from study on human psychology, shows that human behavior is mainly controlled by three (3) key categories of behavior. Conscious/voluntary behavior, Socio-environmental/cultural based behavior and Systemic/learned behavior. Out of the three, while the last one poses as most influential on behavior related energy use, it is also the hardest to affect and change. To effectively counteract the negative effects of user behavior on residential energy use, energy saving devices should react more accordingly to the users and offer engagement. Such a system is an energy monitoring device, which allows for a “double-sided” communication with the user. The user is presented with relevant information about real-time energy use of all of the systems and is able to make changes on the fly. The system should also be able to learn and apply energy saving actions based on user behavior.
1004

Evaluation of bus depot’s environmental impact and recommendations for improvements by material optimisation and improved energy efficiency

Chen, Guojing, Paulsson, Jill January 2015 (has links)
The public transportation in Stockholm is expanding and in order to meet the new demand the amount of buses and depots will have to increase within the city. As a result, it is getting more important to evaluate and analyse the performance of bus depots in order to reduce its environmental impact. The aim of this work is to study the production and operational phase during a bus depot’s life cycle and introduce saving measures that can reduce the emission of carbon dioxide equivalents (CO2eq). This study is conducted in collaboration with Skanska and the depot chosen for this study is currently under construction and located in Charlottendal, Värmdö. A base model is created for the whole bus depot area and the environmental impact is evaluated regarding the activities and usage of materials during production and the energy usage during operation of the depot. The evaluation of the model is performed by using the calculation tools IDA ICE, Anavitor, SPIK and Excel, and the environmental impact is expressed in terms of emission of CO2eq during the lifetime of the depot, which is assumed to be 50 years.  In order to investigate how bus depots can be built to be more climate neutral and energy efficient, several saving measures are evaluated in four cases. The first two cases are focusing on optimising the usage of materials in the building process, by reducing the material groups with the highest environmental impact and considering green construction solutions. The other two cases are aiming towards enhancing the energy performance of the depot, by reducing the usage of energy according to BBR and deliberating an indoor parking place for the buses. The total emission of CO2eq from the base model is determined to be approximately 16 000 tonnes during the lifetime of the depot. About 42 percent of the environmental impact is instigated during the production phase and the rest of the emission is caused by the use of electricity and heat during operation. By considering the implemented measures it can be concluded that the largest reduction in emission can be obtained by optimising the usage of materials on the site, which is achieved by reducing two of the largest materials groups consisting of concrete and asphalt. By reducing the usage of these materials the total emission from the production phase can be reduced by approximately 9 percent and the total emissions can be reduced by up to 4 percent.  To verify the obtained results a sensitivity analysis is performed where three important parameters are investigated. The chosen parameters are; the assumption of the emission factors for the electricity and district heating mixes and the required heating demand for the buses. According to the sensitivity analysis the final results are highly related to the considered parameters. For instance, if the delivered district heating is assumed to be supplied by Fortum, which is the main distributor within Stockholm, it can be concluded that an indoor parking place for the buses is the most beneficial solution to reduce the total emissions. By building a new base hall the emissions instigated from the total heating demand can be reduced by 55 percent and the total emissions can be reduced by 25 percent. / Kollektivtrafiken i Stockholm genomgår i dagsläget en utbyggnation och för att möta det ökade behovet på transportmedel så måste antalet bussar och bussdepåer att öka i området. På grund av detta blir det mer och mer viktigt att utvärdera och analysera bussdepåernas prestanda för att kunna minska miljöpåverkan från dessa verksamheter. Syftet med detta arbete är att studera produktion- och driftfasen under en bussdepås livscykel samt presentera åtgärder som kan leda till en minskning i utsläppen av koldioxidekvivalenter (CO2ekv). Detta arbete utförs i sammarbete med Skanska och den studerade bussdepån, som ligger i Charlottendal på Värmdö, är för tillfället under konstruktion. För att kunna utvärdera den valda depån skapas en basmodell där klimatpåverkan utvärderas utifrån de aktiviteter och material som används i produktionsfasen och den energi som används under driften av depån. De beräkningsverktyg som har används i utvärderingen av depån består av IDA ICE, Anavitor, SPIK och Excel, och klimatpåverkan från depån uttrycks i ton CO2ekv under dess livslängd, vilken har antagits till 50 år. För att undersöka hur depåer kan konstrueras för att vara mer klimatneutrala och energieffektiva så utvärderas olika besparingsåtgärder i fyra fall. Fokus för de två första fallen ligger på att optimera materialanvändningen i byggprocessen, vilket inkluderar en minskning av de material som genererar i de största utsläppen samt en analys av mer miljövänliga konstruktionslösningar. De andra två fallen riktas istället mot att förbättra energiprestandan av depån genom att minska energianvändningen enligt BBR och överväga en inomhusparkering för bussarna.  De totala utsläppen från basmodellen utgör cirka 16 000 ton, där 42 procent orsakas under produktionsfasen och de resterande utsläppen kommer från driften av depån. Utifrån analysen kan man dra slutsatsen att den största minskningen av utsläpp kan åstadkommas genom att dra ner på mängden betong och asfalt i produktionsfasen. Genom att minska på dessa material kan utsläppen från produktionsfasen minskas med ungefär 9 procent och de totala utsläppen kan minskas med 4 procent. I känslighetsanalysen undersöks tre huvudsakliga parametrar som har en stor inverkan på det slutliga resultatet av beräkningarna. Dessa parametrar består av de valda energimixerna för elektricitet och fjärrvärme samt värmebehovet för bussarna. Enligt resultatet i känslighetsanalysen så är en inomhusparkering den förbättringsåtgärd som leder till den största minskningen av utsläpp. Detta resultat fås då fjärrvärmen antas levereras av Fortum, som är den största leverantören i Stockholmsområdet. Genom att investera i en ny busshall kan det totala värmebehovet för bussdepån minskas med 55 procent och det totala utsläppet med 25 procent.
1005

Performance Evaluation of Virtualization in Cloud Data Center

Zhuang, Hao January 2012 (has links)
Amazon Elastic Compute Cloud (EC2) has been adopted by a large number of small and medium enterprises (SMEs), e.g. foursquare, Monster World, and Netflix, to provide various kinds of services. There has been some existing work in the current literature investigating the variation and unpredictability of cloud services. These work demonstrated interesting observations regarding cloud offerings. However, they failed to reveal the underlying essence of the various appearances for the cloud services. In this thesis, we looked into the underlying scheduling mechanisms, and hardware configurations, of Amazon EC2, and investigated their impact on the performance of virtual machine instances running atop. Specifically, several instances with the standard and high-CPU instance families are covered to shed light on the hardware upgrade and replacement of Amazon EC2. Then large instance from the standard family is selected to conduct focus analysis. To better understand the various behaviors of the instances, a local cluster environment is set up, which consists of two Intel Xeon servers, using different scheduling algorithms. Through a series of benchmark measurements, we observed the following findings: (1) Amazon utilizes highly diversified hardware to provision different instances. It results in significant performance variation, which can reach up to 30%. (2) Two different scheduling mechanisms were observed, one is similar to Simple Earliest Deadline Fist (SEDF) scheduler, whilst the other one analogies Credit scheduler in Xen hypervisor. These two scheduling mechanisms also arouse variations in performance. (3) By applying a simple "trial-and-failure" instance selection strategy, the cost saving is surprisingly significant. Given certain distribution of fast-instances and slow-instances, the achievable cost saving can reach 30%, which is attractive to SMEs which use Amazon EC2 platform. / Amazon Elastic Compute Cloud (EC2) har antagits av ett stort antal små och medelstora företag (SMB), t.ex. foursquare, Monster World, och Netflix, för att ge olika typer av tjänster. Det finns en del tidigare arbeten i den aktuella litteraturen som undersöker variationen och oförutsägbarheten av molntjänster. Dessa arbetenhar visat intressanta iakttagelser om molnerbjudanden, men de har misslyckats med att avslöja den underliggande kärnan hos de olika utseendena för molntjänster. I denna avhandling tittade vi på de underliggande schemaläggningsmekanismerna och maskinvarukonfigurationer i Amazon EC2, och undersökte deras inverkan på resultatet för de virtuella maskiners instanser som körs ovanpå. Närmare bestämt är det flera fall med standard- och hög-CPU instanser som omfattas att belysa uppgradering av hårdvara och utbyte av Amazon EC2. Stora instanser från standardfamiljen är valda för att genomföra en fokusanalys. För att bättre förstå olika beteenden av de olika instanserna har lokala kluster miljöer inrättas, dessa klustermiljöer består av två Intel Xeonservrar och har inrättats med hjälp av olika schemaläggningsalgoritmer. Genom en serie benchmarkmätningar observerade vi följande slutsatser: (1) Amazon använder mycket diversifierad hårdvara för att tillhandahållandet olika instanser. Från de olika instans-sub-typernas perspektiv leder hårdvarumångfald till betydande prestationsvariation som kan nå upp till 30%. (2) Två olika schemaläggningsmekanismer observerades, en liknande Simple Earliest Deadline Fist(SEDF) schemaläggare, medan den andra mer liknar Credit-schemaläggaren i Xenhypervisor. Dessa två schemaläggningsmekanismer ger även upphov till variationer i prestanda. (3) Genom att tillämpa en enkel "trial-and-failure" strategi för val av instans, är kostnadsbesparande förvånansvärt stor. Med tanke på fördelning av snabba och långsamma instanser kan kostnadsbesparingen uppgå till 30%, vilket är attraktivt för små och medelstora företag som använder Amazon EC2 plattform.
1006

Energy efficiency measures in a typical Swedish single-family building from the 1960s

Larsson, Emanuel, Ljungqvist Baldesi, Raffaello January 2022 (has links)
Many buildings built in the 1960s are inefficient when it comes to their energy use. A lot of them are also in need of renovating. Therefore, this project is aiming to investigate five different scenarios where the decrease in electricity demand is in focus.One scenario is energy-saving behavior which does not need any investment for a renovation but just decreases the electricity demand by changing the behavior of the people living there.Another option is the building envelope renovation where added insulation to the outer walls, the roof and the floor is added. The windows and entrance doors are also upgraded to more efficient options. A return air only ventilation system is installed as well. The third option is to renovate the reference house to achieve the status of passive house set by Boverket. This is done by adding a much thicker layer of insulation to the building components and adding a FTX ventilation system and at the same time changing the direct electric heating system to a bed rock geothermal heating system. The last two scenarios, net-zero energy building and off-grid building, also use a FTX ventilation system and bed rock geothermal heating system. They have the same thickness as the building envelope renovation. The biggest difference is that the net-zero energy building uses solar power to match the yearly electricity demand and therefore be able to call it net-zero energy. The off-grid house has an electricity storage as well as the solar panels. This is to be able to disconnect from the electric grid completely and only consume electricity produced by the building itself.The last three scenarios all achieve a primary energy below that of what Boverket demand fornew buildings of 90 kWh/m^2, year. The building with the lowest cumulative cost over 50 years is the off-grid building, though this result could vary depending on the price of electricity. The scenario with the lowest investment cost per kWh saved is the net-zero energy building.
1007

Energy improvement options for a small-scale brewery: a literature study

Arana, Eneko January 2022 (has links)
In the age of technology and development in which we live nowadays, it is inevitable to realise that this so-called progress is translated into pollution, damage to the environment and abuse of energy and fossil fuels. The companies and factories that produce the goods we need, use a lot of energy and pollute in massive ways, posing dilemmas such as how to make these companies more energetically and environmentally efficient, with the aim of decreasing the emissions and energy use. This literature review proposes a compilation and update of suggestions made to microbreweries after undergoing an energy audit, in an attempt to make these companies more energy-efficient, competitive, economical and sustainable. The information has been obtained by searching peer-reviewed articles in different databases and re-arranged in this article into sections on energy efficiency measures, waste treatment options and environmental impact. Several studies have been carried out on improving efficiency and trying to decrease the environmental impact of beer production processes. The main issues found during the process are energy efficiency and the generated wastewater. Both problems could be solved either by using an internal boiler that would generate less waste, applying renewable energies or by treating the residues in bioreactors, a field that needs further study. The choice of packaging material will be influenced by customer preferences and material recycling, being glass bottles and aluminium cans the most popular choices.
1008

Adaptive Energy-Control for In-Memory Database Systems

Kissinger, Thomas, Habich, Dirk, Lehner, Wolfgang 30 May 2022 (has links)
The ever-increasing demand for scalable database systems is limited by their energy consumption, which is one of the major challenges in research today. While existing approaches mainly focused on transaction-oriented disk-based database systems, we are investigating and optimizing the energy consumption and performance of data-oriented scale-up in-memory database systems that make heavy use of the main power consumers, which are processors and main memory. We give an in-depth energy analysis of a current mainstream server system and show that modern processors provide a rich set of energy-control features, but lack the capability of controlling them appropriately, because of missing application-specific knowledge. Thus, we propose the Energy-Control Loop (ECL) as an DBMS-integrated approach for adaptive energy-control on scale-up in-memory database systems that obeys a query latency limit as a soft constraint and actively optimizes energy efficiency and performance of the DBMS. The ECL relies on adaptive workload-dependent energy profiles that are continuously maintained at runtime. In our evaluation, we observed energy savings ranging from 20% to 40% for a real-world load profile.
1009

Reinforcement Learning in Eco-driving for Connected and Automated Vehicles

Zhu, Zhaoxuan January 2021 (has links)
No description available.
1010

Green VoIP : A SIP Based Approach

Talaganov, Goce January 2012 (has links)
This master thesis presents, examines, designs, implements, and evaluates with respect to energy efficiency a secure and robust VoIP system. This system utilizes a Session Initiation Protocol (SIP) infrastructure assisted by a cloud service, specifically focusing on small to medium sized enterprises (SME) and homes. This research focuses on using inexpensive, flexible, commodity embedded hardware (specifically a Linksys WRT54GL wireless router for the local site with a customized operating system, specifically DD-WRT). The idea is to reduce the local site's power consumption to very low levels by examining which functions can be done in a cloud service rather than at the local site. The thesis presents the design of a low-power IP telephony system for the local site and the cloud site. A number of different usage scenarios and desirable features are described. The methodology for conducting a set of experiments is defined to perform stress-testing and to evaluate the low- power IP telephony system's design. The experiments concern the overall power consumption of the local site under various configurations, the VPN link's call capacity, the QoS metrics for the VoIP calls, the session request delay (SRD) and the registration request delay (RRD). The results from these experiments show that there is a potential for significant power savings when using the proposed design for an IP telephony system. / Detta examensarbete presenterar, undersöker, utformar, implementerar, och försöker att utvärdera ett säkert och robust VoIP-system med energieffektivitet. Detta system använder en Session Initiation Protocol (SIP)-infrastruktur med hjälp av en molntjänst med särskild inriktning på, små, och medelstora företag (SME) och hemmanvändare. Denna forskning fokuserar att använda en prisvärt, billig, flexibel, med program inbyggd hårdvara (speciellt en Linksys WRT54GL trådlös router för den lokala platsen med ett anpassat operativsystem DD-WRT). Tanken är att minska energiförbrukningen på, den lokala platsen till mycket låga nivåer genom att undersöka vilka funktioner, som kan köras på, ett molntjnst snarare än på, den lokala platsen. Avhandlingen presenterar utformningen av ett IP-telefonisystem på, den lokala platsen med ett lågt strömbehov och på, molntjänsten. Ett antal olika användningsförhållanden och önskvärda egenskaper är beskrivna. Metodiken för att genomföra en rad experiment definieras för att utföra stresstester och för att utvärdera designen av IP-telefonisystem med ett lågt effektbehov. I försöken experimenteras den totala energiförbrukningen av den lokala platsen under olika konfigurationer, VPN-länkens samtalskapacitet, QoS-mätning för VoIP-samtal, Session Request Delay (SRD) och Registration Request Delay (RRD). Resultaten från dessa experiment visar att det finns en potential för betydande energibesparing när du använder den föreslagna designen för en IP-telefoni system.

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