<div>Neuromorphic systems promise a novel alternative to the standard von-Neumann architectures that are computationally expensive for analyzing big data, and are not efficient for learning and inference. This novel generation of computing aims at ``mimicking" the human brain based on deploying neural networks on event-driven hardware architectures. A key bottleneck in designing such brain-inspired architectures is the complexity of co-optimizing the algorithm’s speed and accuracy along with the hardware’s performance and energy efficiency. This complexity stems from numerous intrinsic hyperparameters in both software and hardware that need to be optimized for an optimum design.</div><div><br></div><div>In this work, we present a versatile hierarchical pseudo agent-based multi-objective hyperparameter optimization approach for automatically tuning the hyperparameters of several training algorithms (such as traditional artificial neural networks (ANN), and evolutionary-based, binary, back-propagation-based, and conversion-based techniques in spiking neural networks (SNNs)) on digital and mixed-signal neural accelerators. By utilizing the proposed hyperparameter optimization approach we achieve improved performance over the previous state-of-the-art on those training algorithms and close some of the performance gaps that exist between SNNs and standard deep learning architectures.</div><div><br></div><div>We demonstrate >2% improvement in accuracy and more than 5X reduction in the training/inference time for a back-propagation-based SNN algorithm on the dynamic vision sensor (DVS) gesture dataset. In the case of ANN-SNN conversion-based techniques, we demonstrate 30% reduction in time-steps while surpassing the accuracy of state-of-the-art networks on an image classification dataset (CIFAR10) on a simpler and shallower architecture. Further, our analysis shows that in some cases even a seemingly minor change in hyperparameters may change the accuracy of these networks by 5‑6X. From the application perspective, we show that the optimum set of hyperparameters might drastically improve the performance (52% to 71% for Pole-Balance control application). In addition, we demonstrate resiliency of different input/output encoding, training neural network, or the underlying accelerator modules in a neuromorphic system to the changes of the hyperparameters.</div>

Kraven på att nybyggda bostäder ska vara energisnåla i driftskedet ökar hela tiden av flera anledningar. Dels vill brukarna hålla driftskostnaderna så låga som möjligt och dels är det miljöaspekten som spelar in. Men hur energisnål kan en villa egentligen göras och hur påverkas arkitekturen då den görs extremt energieffektiv? I den här rapporten utreds tio energieffektiva principer som kan användas för att göra en villa mer energisnål och energiproducerande. Alla tio principer har tillämpats i en villa som projekterats under arbetets gång. De tio principerna är: Husets utformning Konstruktion Isolerade skjutluckor Solceller Solavskärmning Energitak Uppvärmningssystem Vindkraftverk Vindskydd Medvetenhet och inredning Resultaten visar att villan kommer ge ett energiöverskott på cirka 6 000 kWh/år enligt enklare handberäkningar av husets energiförbrukning och den producerade energin. Arkitekturen blir tydligt påverkad av de energieffektiva principerna men huset är ändå fullt funktionellt. Att tillämpa tio energieffektiva principer i en villa kan vara svårt att försvara ekonomiskt då pay-off tiderna är långa på grund av höga investeringskostnader. Arbetet har utförts på KTH campus Haninge i samarbete med Sweco Architects AB. / The demands on newly constructed buildings to be energy efficient in the operational stage are increasing all the time by many reasons. Partly because the people living in the house want to keep the operational costs as low as possible and partly because of the impact on the environment. But how energy efficient can a villa be made and how does it affect the architecture when it is made extremely energy efficient? In this essay ten energy efficient principles are investigated which can be used to make a villa more energy efficient and energy producing. All ten principles have been applied in one villa that has been designed during this project. The ten principles are: The design and shape of the house Construction Insulated sliding slots Solar panels Sun shading Energy roof Heating system Wind power turbine Wind protection Consciousness and interior design The results show that the villa will produce an overbalance of energy of about 6 000 kWh/year according to simpler calculations of the house´s energy consumption and the energy that it produces. The architecture is clearly affected by the energy efficient principles but the house is still fully functioning. Applying ten energy efficient principles in one villa can be hard to motivate economically because of long pay-off times caused by high investment costs. This thesis has been made at KTH campus Haninge in cooperation with Sweco Architects AB.

In Sweden, there are around 300 000 multi-family buildings with high energy consumption state a high renovation potential in the building sector. This study aims to analyze different renovation measures for a typical theoretical multi-family building to determine their effects on energy consumption, financial profitability, and impacts on obtaining an energy label in the rating system. The reference building was created based on the given energy consumption for the Nils Holgersson building (NH), where the information data accumulated and assessed utilizing dynamic energy simulation software IDA ICE.The selected renovation measures include modifications to the building envelope and ventilation. The reference building was equipped with an exhaust ventilationsystem with no heat recovery. The study showed that heat losses through ventilation contributed to the largest share. The losses through windows and walls are significant; hence selecting ventilated façade and adding insulation were relevant efficiency measures. The study analysis a vacuum insulation panel (VIP) applied for external walls due to its highly efficient thermal properties compared to conventional insulation. The results of life cycle cost analyses (LCCA) for 40 years demonstrated that VIP and ventilated façade have an economic benefit because of the energy cost saving during the operation phase of the building, despite the high initial cost. The cumulative LCC for each measure showed that VIP approaching the conventional insulation within theservice life the ventilated façade is cost-efficient at the end of the 6thyear compared to changing glazing. The selected rating system is Miljöbyggnad (MB). After renovation, the NH building could achieve the bronze level on the energy indicators.The study found that the energy consumption in the base model was 144.7 kWh/m2and the implemented renovation package leads to a reduction of 47 % annual heating demand. As a rule of thumb, the annual energy demand will be 90 kWh/m2, and the cost for the renovation package including installation would be 1150 SEK/m2causing a total energy-saving 2900 SEK/m2at the end of 40 years.

Wireless sensor networks (WSNs) groups specialized transducers that provide sensing services to Internet of Things (IoT) devices with limited energy and storage resources. Since replacement or recharging of batteries in sensor nodes is almost impossible, power consumption becomes one of the crucial design issues in WSN. Clustering algorithm plays an important role in power conservation for the energy constrained network. Choosing a cluster head (CH) can appropriately balance the load in the network thereby reducing energy consumption and enhancing lifetime. This paper focuses on an efficient CH election scheme that rotates the CH position among the nodes with higher energy level as compared to other. The algorithm considers initial energy, residual energy, and an optimum value of CHs to elect the next group of CHs for the network that suits for IoT applications, such as environmental monitoring, smart cities, and systems. Simulation analysis shows the modified version performs better than the low energy adaptive clustering hierarchy protocol by enhancing the throughput by 60%, lifetime by 66%, and residual energy by 64%.

Cette thèse porte sur l'étude des problèmes posés par l'implémentation d'un système de fichiers passant à l'échelle, pour un noyau de type UNIX sur une architecture manycore NUMA à cohérence de cache matérielle et à faible empreinte énergétique. Pour cette étude, nous prenons comme référence l'architecture manycore généraliste TSAR et le noyau de type UNIX ALMOS.L'architecture manycore visée pose trois problèmes pour lesquels nous apportons des réponses après avoir décrit les solutions existantes. L'un de ces problèmes est spécifique à l'architecture TSAR tandis que les deux autres sont généraux.Le premier problème concerne le support d'une mémoire physique plus grande que la mémoire virtuelle. Ceci est dû à l'espace d'adressage physique étendu de TSAR, lequel est 256 fois plus grand que l'espace d'adressage virtuel. Pour résoudre ce problème, nous avons profondément modifié la structure noyau pour le décomposer en plusieurs instances communicantes. La communication se fait alors principalement par passage de messages.Le deuxième problème concerne la stratégie de placement des structures du système de fichiers sur les nombreux bancs de mémoire. Pour résoudre ce problème nous avons implémenté une stratégie de distribution uniforme des données sur les différents bancs de mémoire.Le troisième problème concerne la synchronisation des accès concurrents. Pour résoudre ce problème, nous avons mis au point un mécanisme de synchronisation utilisant plusieurs mécanismes. En particulier, nous avons conçu un mécanisme lock-free efficace pour synchroniser les accès faits par plusieurs lecteurs et un écrivain. Les résultats expérimentaux montrent que : (1) l'utilisation d'une structure composée de plusieurs instances communicantes ne dégrade pas les performances du noyau et peut même les augmenter ; (2) l'ensemble des solutions utilisées permettent d'avoir des résultats qui passent mieux à l'échelle que le noyau NetBSD ; (3) la stratégie de placement la plus adaptée aux systèmes de fichiers pour les architectures manycore est celle distribuant uniformément les données. / In this thesis we study the problems of implementing a UNIX-like scalable file system on a hardware cache coherent NUMA manycore architecture. To this end, we use the TSAR manycore architecture and ALMOS, a UNIX-like operating system.The TSAR architecture presents, from the operating system point of view, three problems to which we offer a set of solutions. One of these problems is specific to the TSAR architecture while the others are common to existing coherent NUMA manycore.The first problem concerns the support of a physical memory that is larger than the virtual memory. This is due to the extended physical address space of TSAR, which is 256 times bigger than the virtual address space. To resolve this problem, we modified the structure of the kernel to decompose it into multiple communicating units.The second problem is the placement strategy to be used on the file system structures. To solve this problem, we implemented a strategy that evenly distributes the data on the different memory banks.The third problem is the synchronization of concurrent accesses to the file system. Our solution to resolve this problem uses multiple mechanisms. In particular, the solution uses an efficient lock-free mechanism that we designed, which synchronizes the accesses between several readers and a single writer.Experimental results show that: (1) structuring the kernel into multiple units does not deteriorate the performance and may even improve them; (2) our set of solutions allow us to give performances that scale better than NetBSD; (3) the placement strategy which distributes evenly the data is the most adapted for manycore architectures.

No description available.

Sustainability is one of the challenges in today’s world. With limited resources at hand and hazardous impact of manufacturing processes on the environment, there is an increasing need for sustainable manufacturing. Sustainability actually has a broad meaning and is an all-inclusive concept. In this thesis what we are more interested in and focus on, are energy consumption and environmental impacts. Using system dynamics modeling and simulation, we can more easily understand the behavior of processes. Our selected processes are turning, milling and drilling operations in crankshaft machining and using system dynamics concept we model these processes with regards to energy consumption and environmental concerns. The output of this thesis work can be eventually used as a decision support tool to decide how to make processes more sustainable.

The use of IT in companies is constantly expanding, and therefore, so is the energy consumption and carbon footprint from IT. If companies do not take steps towards more sustainable IT usage, the footprint will continue to expand, toxic metals will be used in hardware and the usage of world resources will not become more circular. Few studies are made regarding internal and external factors that affect the implementation of sustainable IT. Sustainability is seen as a “core IT objective” by 90% of European IT leaders. There is a knowledge gap concerning internal and external demands within sustainable IT, since no research studies have been found. The aim of this study is to understand what large companies in Sweden do to act more sustainably in their IT usage. What demands are put on suppliers to make more sustainable solutions and which demands are put on employees internally to make their IT usage more sustainable. The research question is: “What external sustainability demands do large companies put on their suppliers of IT systems and hardware, and what internal demands do the companies have on their own IT usage?”. This study will be carried out using survey as a research strategy. Data will be collected from semi-structured interviews with employees from nine different companies as well as the collection of internal documents and documents from the websites of the companies. The data analysis method used is thematic analysis. From the interviews with employees with high knowledge in the companies sustainable IT work, five themes with sixteen different demands were found. Five of the demands were identified as new that previous research has not addressed while the remaining eleven demands can be found in previous research. Some of the demands were repeated no matter how long the company have worked with sustainable IT, such as Recycling hardware, Increasing the life cycle, Involve employees in sustainable IT, Server location and Move to cloud computing. While other demands like System boundaries, Sustainable software development, and Sustainably developed software were more common among more mature companies within sustainable IT. This study found that the two most considerable demands are the external demand Hardware can be recycled and the internal demand Recycling hardware, which implies that circularity has become a more critical topic.

Yes / The paper presents the general requirements and an exemplary design of the RF front-end system that in today's handset is a key consumer of power. The design is required to minimize the carbon footprint in mobile handsets devices, whilst facilitating cooperation, and providing the energy-efficient operation of multi-standards for 5G communications. It provides the basis of hardware solutions for RF front-end integration challenges and offers design features covering energy efficiency for power amplifiers (PAs), Internet of Things (IoT) controlled tunable filters and compact highly isolated multiple-input and multiple-output (MIMO) antennas. An optimum design requires synergetic collaboration between academic institutions and industry in order to satisfy the key requirements of sub-6 GHz energy-efficient 5G transceivers, incorporating energy efficiency, good linearity and the potential for low-cost manufacturing. A highly integrated RF transceiver was designed and implemented to transmit and receive a picture using compact MIMO antennas integrated with efficient tunable filters and high linearity PAs. The proposed system has achieved a bit error rate (BER) of less than 10-10 at a data rate of 600 Mb/s with a wireless communication distance of more than 1 meter and power dissipation of 18-20 mW using hybrid beamforming technology and 64-QAM modulation. / 10.13039/100010665-H2020 Marie Skodowska Curie

The numerous buildings that currently require thermal rehabilitation in Romania means that substantial resources and a large number of competent people are required to carry out surveys and energy audits. However, commercial energy balance software is mostly unaffordable for those organisations involved in this process. This paper describes an energy balance programme – ENEFControl – developed to be a rapid, low cost, local tool able to assist in the choice of energy efficient solutions for buildings. To test the software, thermal and energy analyses were carried out on a 1970s built apartment block in Transylvania. Based on these analyses, three constructive scenarios were proposed for thermal rehabilitation. Compared to the performance of the analysed building, the thermal and energy performance of the retrofitted building in all three scenarios significantly improved. Since European Union accession in 2007, rapidly rising energy costs have affected the Romanian population. ENEFControl offers Romanian engineers and architects an opportunity to speed up the rehabilitation programme of buildings without the need for more expensive expertise and tools.