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Just like current software systems, models are characterised by increasing complexity and rate of change. Yet, these models only become useful if they can be continuously evaluated and validated. To achieve sufficiently low response times for large models, incremental analysis is required. Reference Attribute Grammars (RAGs) offer mechanisms to perform an incremental analysis efficiently using dyn
During the last decade the variation in the human genome has been mapped in fine detail. Next generation sequencing has made it possible to cheaply and rapidly aquire vast amounts of biomolecular information on large cohorts of people. This have enabled large-scale epidemiological studies to investigate the relationships between environmental and genetic factors and human biomolecular traits. It i
We propose and analyze distributed computation algorithms for finite-horizon optimal control problems in transportation networks. We model traffic flow dynamics by the cell-transmission model and focus on two problems: system-optimum dynamic traffic assignment (where the routing is part of the optimization) and freeway network control (where the routing is exogenous and the optimization is confine
Massive multiple-input multiple-output (MIMO) is one of the key candidates for the upcoming 5G wireless generation. It offers a multitude of advantages over traditional techniques, such as reduced latency, reduced interference among user equipments (UEs) and increased spectrum and energy efficiencies. However, to verify the theoretically promised gains in real-life, prototype systems are inevitabl
Air-to-air refueling is a vital technique for extending the range and endurance of manned or unmanned aircraft, with over 1000 refueling procedures flown per day in military operations. The hardware used for air-to-air refueling needs to be tailored to the specific aircraft and airspeeds involved, performing markedly different for permutations of tanker and receiver craft. Extensive flight testing
Optimization problems with rank constraints appear in many diverse fields such as control, machine learning, and image analysis. Since the rank constraint is nonconvex, these problems are often approximately solved via convex relaxations. Nuclear norm regularization is the prevailing convexifying technique for dealing with these types of problem. This paper introduces a family of low-rank inducing
Despite the creativity of the scientific community and the funding agencies, the underlying model of computation behind IoT, WSN, cloud, edge, fog, and mist is fundamentally the same; Computational nodes which are dynamically interconnected to form a system in where both processing capacity and connectivity may vary over time. On top of such a system, we consider applications that need packets to
For a firm in an open source software (OSS) ecosystem, the requirements engineering (RE) process is rather multifaceted. Apart from its typical RE process, there is a competing process, external to the firm and inherent to the firm’s ecosystem. When trying to impose an agenda in competition with other firms, and aiming to align internal product planning with the ecosystem’s RE process, firms need
Context: In the Requirements Engineering (RE) process of an Open Source Software (OSS) community, an involved firm is a stakeholder among many. Conflicting agendas may create miss-alignment with the firm's internal requirements strategy. In communities with meritocratic governance or with aspects thereof, a firm has the opportunity to affect the RE process in line with their own agenda by gaining
In this thesis, a class of linear time-invariant systems is identified for which a particular type of H-infinity optimal control problem can be solved explicitly. It follows that the synthesized controller can be given on a simple explicit form. More specifically, the controller can be written in terms of the matrices of the system’s state-space representation. The result has applications in the c
Providing information security is crucial for the Internet of Things (IoT) devices, platforms in which the available power budget is very limited. This paper tackles this challenge and presents a cryptographic processor compliant with the security algorithms specified by the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) NarrowBand IoT (NB-IoT) standard. The proposed processor
In this paper we present fully decentralized methods for calculating an approximate zero- forzing (ZF) equalizer in a large intelligent surface (LIS). A LIS is intended for wireless communication and facilitates unprecedented MU- MIMO performance, far superior to that of Massive MIMO. Antenna modules in the grid connect to their neighbors to exchange messages of information needed for interference
This paper presents the architecture and the corresponding simulation results for a very low power half-rate extended Hamming (8,4) decoder implemented in analog integrated circuitry. TI’s 65nm low power CMOS design library was used to simulate the complete decoder including an input interface, an analog decoding core and an output interface. The simulated bit error rate (BER) performance of the d
Statistical model results suggest that the declining growth rate from autumn to spring is the key to cause El Niño-Southern Oscillation (ENSO) spring persistence barrier (SPB). Using a dynamical approach, we develop the physical mechanisms responsible for ENSO SPB in the framework of recharge oscillator by adding a seasonally varying Bjerknes (BJ) stability index and linking it with ENSO growth ra
The proliferation of connected embedded devices, or the Internet of Things (IoT), together with recent advances in machine intelligence, will change the profile of future cloud services and introduce a variety of new research problems centered around empowering resource-limited edge devices to exhibit intelligent behavior, both in sensing and control. Cloud services will enable learning from data,
This thesis treats the intersection between two of the largest transformations we are seeing within our society today; the cloud and the Internet-of-Things (IoT). The aim of this thesis is to investigate different ways to model and control a network of cloud services so that timing-critical IoT applications can make use of them. Examples of such applications can be autonomous and mobile robots, sm
Internet-of-things (IoT) systems consist of spatially distributed devices with services. Compared to desktop applications, IoT systems are always running and need to deal with unresponsive devices and weak connectivity. In this thesis, we examine the following question: How can we simplify the development of IoT systems? We begin to answer this question by proposing a domain-specific language (DSL
Recent warming in the Arctic, which has been amplified during the winter1–3, greatly enhances microbial decomposition of soil organic matter and subsequent release of carbon dioxide (CO2)4. However, the amount of CO2 released in winter is not known and has not been well represented by ecosystem models or empirically based estimates5,6. Here we synthesize regional in situ observations of CO2 flux f
High-energy linear particle accelerators enable exploration of the microscopic structure of pharmaceuticals, solar cells, fuel cells, high-temperature superconductors, and the universe itself. These accelerators accelerate charged particles using oscillating magnetic fields that are confined in metal cavities. The amplitudes and phases of the electromagnetic fields need to be accurately controlled
This thesis focuses on the terminal aspects of massive MIMO systems. Based on the degree of freedom a terminal have in a MaMi, different antenna configurations, transceiver topologies with associated transmission schemes, and the underlying algorithms are researched.The first studied topic concerns multiple-antenna terminals in a massive MIMO system for sub-6 GHz, operated at the center frequency
