Filetype
We consider weighted sequence spaces on N with increasing weights. Given a fixed integer k and a Hankel operator Gamma on such a space, we show that the kth singular vector generates an analytic function with precisely k zeroes in the unit disc, in analogy with the classical AAK-theory of Hardy spaces. We also provide information on the structure of the singular spectrum for Hankel operators, appl
Context: Coping with rapid requirements change is crucial for staying competitive in the software business. Frequently changing customer needs and fierce competition are typical drivers of rapid requirements evolution resulting in requirements obsolescence even before project completion. Objective: Although the obsolete requirements phenomenon and the implications of not addressing them are known,
We consider the effect of signaling rate (baud rate) on the information rate of single carrier linear transmission systems with Gaussian inputs. Several different communication scenarios are investigated: correlated or uncorrelated symbols, a fixed modulation pulse or a modulation pulse varying with the signaling rate and frequency selective or flat channels. For uncorrelated symbols, we show that
The topic of this thesis is estimation of nonlinear dynamical systems, focusing on the use of methods such as particle filtering and smoothing. There are three areas of contributions: software implementation, applications of nonlinear estimation and some theoretical extensions to existing algorithms. The common theme for all the work presented is the pyParticleEst software framework, which has b
Abstract in UndeterminedFaster-than-Nyquist (FTN) signaling is a method of improving bandwidth efficiency by transmitting information beyond Nyquist's orthogonality limit for interference free transmission. Previously have theoretically established that FTN can provide improved bandwidth efficiency. However, this comes at the cost of higher decoding complexity at the receiver. Our work has evaluat
The thesis discusses closed-loop control of the hypnotic and the analgesic components of anesthesia. The objective of the work has been to develop a system which independently controls the intravenous infusion rates of the hypnotic drug propofol and analgesic drug remifentanil. The system is designed to track a reference hypnotic depth level, while maintaining adequate analgesia. This is complicat
A widespread and flexible use of robots in rapidly changing working environments could be greatly enhanced by human-robot interaction and collaboration. Humans and robots have complementary skills. The robotic worker can relieve the human from repetitive work, and the human can make robot deployment easier by managing nonstandard or particularly skilful operations. Such a scenario, however, requir
Composition is a practice of key importance in software engineering. When real-time applications are composed, it is necessary that their timing properties (such as meeting the deadlines) are guaranteed. The composition is performed by establishing an interface between the application and the physical platform. Such an interface typically contains information about the amount of computing capacity
Model order selection is an important element in system identification. It is well known that common model order selection methods such as Akaike’s information criterion (AIC) and Bayesian’s information criterion (BIC) neglect relevant information that is available in models of order different from the one chosen. In this paper the model order selection problem for receivers similar to those found
Modern industrial robots are traditionally programmed to follow desired trajectories, with the only feedback coming from the internal position/angle sensors in the joints. The robots are in general very accurate in tracking the desired motion, and they have become indispensable in many applications, such as spot welding and painting in the automotive industry. In more complex tasks, such as physic
This paper presents a mathematical approach and numerical model that simulates beach and dune change in response to cross-shore processes of dune growth by wind and dune erosion by storms, and by gradients in longshore sand transport that will alter shoreline position. Sub-aerial transport processes are represented, whereas sub-aqueous transport is neglected. The system is tightly coupled morpholo
Background: Software ecosystems emerged as means for several actors to jointly provide more value to the market than any of them can do on its own. Recently, software ecosystems are more often used to support the development of hardware-dependent solutions. Objectives: This work aims at studying barriers and bridges to participation in an ecosystem with substantial hardware dependencies. Method: W
In this paper a controller reduction method which preserves closed loop stability is described. A Lyapunov inequality based sufficient condition is proposed in the search of the reduced controller. The reduced controller leads to a stable closed loop system with guaranteed approximation quality. Furthermore, the proposed problem can be formulated as a matrix approximation problem which can be solv
Wave damping in vegetation in shallow lakes reduces resuspension and thereby improves the light climate and decreases nutrient recycling. In this study, wave transformation in reed (Phragmites australis) was measured in a shallow lake. Theoretical models of wave height decay, based on linear wave theory, and transformation of the probability density function (PDF), using a wave-by-wave approach, w
Regression testing is verifying that previously functioning software remains after a change. With the goal of finding a basis for further research in a joint industry-academia research project, we conducted a systematic review of empirical evaluations of regression test selection techniques. We identified 27 papers reporting 36 empirical studies, 21 experiments and 15 case studies. In total 28 tec
The proposed time-to-digital converter (TDC) arranges two Vernier gated-ring-oscillator (GRO) branches in a 2-dimension (2-D) fashion. All delay differences between X-axis phases and Y-axis phases (based on 2-D definition) can be used, rather than only the diagonal line. The large latency time inherited from Vernier structure is therefore dramatically reduced. The TDC is implemented in a 90nm CMOS
The COST 2100 channel model is a geometry-based stochastic channel model (GSCM) that can reproduce the stochastic properties of multi-link Multiple-Input Mulitple-Output (MIMO) channels over time, frequency and space. By contrast to other popular GSCMs, the COST 2100 approach is generic and flexible, making it suitable to model multi-user or distributed MIMO scenarios. In this paper a concise over
Recent years have seen an increasing attention given to wireless Personal Area Networks (PANs), which are typically networks with small transmitter-receiver (TX-RX) separation. The desire for high data rates has led to an interest in deploying multiple-input multiple-output (MIMO) transmission for such systems, but up until this date there exists, to the authors’ best knowledge, no MIMO channel mo
We present a 2nd-order 4-bit continuous-time (CT) delta-sigma modulator (DSM) employing a 2nd-order loop filter with a single operational amplifier. This choice strongly reduces the power consumption, since operational amplifiers are the most power hungry blocks in the DSM. The DSM has been implemented in a 65 nm CMOS process, where it occupies an area of . It achieves an SNDR of 64 dB over a 500
