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Introduction– The purpose of the study was to be able to examine and present energy-efficient solutions for future new constructions for multi-dwelling buildings with aim on design. It was based on investigating the causes and reasons for the high energy consumption in apartment buildings, as well as investigating the connection between energy change and environmental impact. Method – The chosen method for this work was a case study which is a qualitative research method. The method had a purpose that focuses on identifying problems and describing in depth how, why, and which measures are suitable for reducing energy consumption in apartment buildings. The work combined quantitative and qualitative research methods. For a better understanding of the research topic, a qualitative literature review of various literature and scientific reports was carried out. There, a certain number of interviews were conducted with several architects and engineers where questions about the research topic were asked. Results – Under the results chapter, the standards, and requirements as well as other building specifications for multi-dwelling buildings that affected energy were presented. Furthermore, several solution possibilities and techniques were presented. In addition, the interview answers that have the clearest connection to the question. Finally, it led to the primary energy number not being allowed to rise above 75 [kWh/m2 Atemp and year], a good facade material choice can be brick and concrete. Certain technical solutions can contribute to less energy consumption such as air heat exchange and solar cells, and the environmental impact is connected with energy consumption. Analysis – During the analysis of empirical evidence, it is pointed out the factors that cause high energy consumption in apartment buildings. In addition, the solution options that led to a reduction in energy consumption and energy efficiency for apartment buildings are revealed. Furthermore, the connection between change in energy consumption and environmental impact is brought together. Discussion – The case study showed that there were several factors behind high energy consumption in apartment buildings, partly linked to design, partly linked to socio-economic conditions. Based on both literatures, the study and interviews, reliable data could be obtained to answer questions. Furthermore, the chapter contains advantages and disadvantages of using the case study method and data collection techniques. Keywords: Energy reduction, Energy consumption, Energy efficiency, Apartment building, Solution possibility, Environmental impact, new constructions, Design. / Introduktion – Syftet med studien var att kunna undersöka och presentera fram energieffektiva lösningar för framtida nybyggnationer för flerbostadshus med fokus på utformning. Det var med utgångpunkt på att undersöka orsaker och anledningar till de höga energiförbrukningarna i flerbostadshus, samt att undersöka sambandet mellan energiförändring och miljöpåverkan Metod – Den valda metoden för detta arbete var en fallstudie som är en kvalitativ forskningsmetod. Metoden har ett syfte som fokuserar på att identifiera problem och beskriva djupgående kring hur, varför och vilka åtgärder som är lämpliga för minskning av energiförbrukning i flerbostadshus. I arbetet kombinerades kvantitativa och kvalitativa undersökningsmetoder. För en bredare förståelses kring forskningsämnet så utfördes en kvalitativ litteraturstudie av olika litteraturer och vetenskapliga rapporter. Därpå genomfördes intervjuer med arkitekter och ingenjörer där frågor kring forskningsämnet ställdes. Resultat – Under resultatkapitel presenteras de standarder och krav samt andra byggspecifikationer för flerbostadshus som berörde energi. Vidare uppvisades det flertal lösningsmöjligheter och tekniker. Dessutom de intervjusvar som har tydligast koppling till frågeställningarna. Slutligen lede det till att det primära energitalet få inte stiga över 75 [kWh/m2 Atemp och år], ett bra fasad materialval kan vara tegel och betong, visa tekniska lösningar kan bidra till mindre energiförbrukning liksom luftvärmeväxling och solceller, samt miljöpåverkan hänger ihop med energiförbrukningen.      Analys – Under analys av empiri så påpekas det på de faktorer som orsakar hög energiförbrukning inom flerbostadshus. Dessutom så tyder de lösningsmöjligheter som leder till minskning av energiförbrukning och effektivisering av energi för flerbostadshus. Vidare i kapitlet sammanfördes sambanden mellan förändring i energiförbrukning och miljöpåverkan. Diskussion – Fallstudien visade att det finns flera faktorer bakom hög energiförbrukning i flerbostadshus, dels det som var kopplat till utformning, dels kopplat till socioekonomiska förhållanden. Utifrån både litteraturstudie och intervjuerna kunde trovärdiga data inhämtas för att besvara frågeställningarna. Vidare så innehåller kapitlet fördelar och nackdelar med användning av fallstudie som metod och datainsamlingsteknikerna. Nyckelord – Energireduktion, Energiförbrukning, Energieffektivitet, Flerbostadshus, Lösningsmöjlighet, Miljöpåverkan, Nybyggnationer, Utformning.

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No / A wireless sensor network is a network of large numbers of sensor nodes, where each sensor node is a tiny device that is equipped with a processing, sensing subsystem and a communication subsystem. The critical issue in wireless sensor networks is how to gather sensed data in an energy-efficient way, so that the network lifetime can be extended. The design of protocols for such wireless sensor networks has to be energy-aware in order to extend the lifetime of the network because it is difficult to recharge sensor node batteries. We propose a protocol to form clusters, select cluster heads, select cluster senders and determine appropriate routings in order to reduce overall energy consumption and enhance the network lifetime. Our clustering protocol is called an Efficient Cluster-Based Communication Protocol (ECOMP) for Wireless Sensor Networks. In ECOMP, each sensor node consumes a small amount of transmitting energy in order to reach the neighbour sensor node in the bidirectional ring, and the cluster heads do not need to receive any sensed data from member nodes. The simulation results show that ECOMP significantly minimises energy consumption of sensor nodes and extends the network lifetime, compared with existing clustering protocol.

The paper presents a new cluster based routing algorithm that exploits the redundancy properties of the sensor networks in order to address the traditional problem of load balancing and energy efficiency in the WSNs.The algorithm makes use of the nodes in a sensor network of which area coverage is covered by the neighbours of the nodes and mark them as temporary cluster heads. The algorithm then forms two layers of multi hop communication. The bottom layer which involves intra cluster communication and the top layer which involves inter cluster communication involving the temporary cluster heads. Performance studies indicate that the proposed algorithm solves effectively the problem of load balancing and is also more efficient in terms of energy consumption from Leach and the enhanced version of Leach.

Earlier designs were driven by the goal of achieving higher performance, but lately, energy efficiency has emerged as an even more important design principle. Strong demand from the consumer electronics drives research in the low power and energy-efficient methodologies. Moreover, with exponential increase in the number of transistors on a chip and with further technology scaling, variability in the design is now of greater concern. Variations can make the design unreliable or the design may suffer from sub-optimal performance. Through the work in this thesis, we present a multi-dimensional investigation into the design of variation aware energy-efficient systems. Our overarching methodology is to use system-level decisions to mitigate undesired effects originating from device-level and circuit-level issues. We first look into the impact of process variation (PV) on energy efficient, scalable throughput many-core DSP systems. In our proposed methodology, we leverage the benefits of aggressive voltage scaling (VS) for obtaining energy efficiency while compensating for the loss in performance by exploiting parallelism present in various DSP designs. We demonstrate this proposed methodology consumes 8% - 77% less power as compared to simple dynamic VS over different workload environments. Later, we show judicious system-level decisions, namely, number of cores, and their operating voltage can greatly mitigate the effects of PV and consequently, improve the energy efficiency of the design. We also present our analysis discussing the impact of aging on the proposed methodology. To validate our proposed system-level approach, design details of a prototype chip fabricated in the 90nm technology node and its findings are also presented. The chip consists of 8 homogeneous FIR cores, which are capable of running from near-threshold to nominal voltages. In the 20-chip population, we observe 7% variation in the speed at nominal voltage (0.9V) and 26% at near threshold voltage (0.55V) among all the cores. We also observe 54% variation in power consumption characteristics of the cores. The chip measurement results show that our proposed methodology of judiciously selecting the cores and their operating voltage can result in 6.27% - 28.15% more energy savings for various workload environments, as compared to globally voltage scaled systems. Furthermore, we present the impact of temperature variations on the energy-efficiency of the above systems. We also study the problem of voltage variations in the integrated circuits. We first present the characteristics of a dynamic voltage noise as measured on a 28nm FPGA. We propose a fully digital on-chip sensor that can detect the fast voltage transients and alert the system of voltage emergency. A traditional approach to mitigate this problem is to use safety guardbands. We demonstrate that our proposed sensor system will be 6% - 27.5% more power efficient than the traditional approach. / Ph. D.

In recent years, significant progress has been made in improving the performance of unmanned air vehicles in terms of aerodynamic performance, endurance, autonomy, and the capability of on-board sensor packages. UAVs are now a vital part of both military actions and scientific research efforts. One of the newest classes of UAV is the high altitude long endurance or HALE UAV. This thesis considers the high-level control problem for a unique HALE mission involving cooperative solar powered UAVs. Specifically addressed is energy efficient path planning for vehicles that physically link together in flight to form a larger, more energy efficient HALE vehicle. Energy efficient docking is developed for the case of multiple vehicles at high altitude with negligible wind. The analysis considers a vehicle governed by a kinematic motion model with bounded turn rate in planar constant altitude flight. Docking is demonstrated using a platform-in-the-loop simulator which was developed to allow virtual networked vehicles to perform decentralized path planning and estimation of all vehicle states. Vehicle behavior is governed by a status which is commanded by a master computer and communication between vehicles is intermittent depending on each vehicle's assessment of situational awareness. Docking results in a larger vehicle that consumes energy at 21% of the rate of an individual vehicle and increases vehicle range by a factor of three without considering solar recharging. / Master of Science