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The application of feedback control to computing systems is a promising research area, but has to date been hindered by the almost unanimously perceived complexity in creating control-oriented system models. Computing systems are in fact considered very hard to describe with dynamic models allowing for simple and powerful control design tools, so that complex ones need bringing in to the detriment
We consider the problem of modeling and control of the nonlinear dynamics of a micro manipulator, utilized for machining operations in combination with industrial robots. Position control of the micro manipulator is a challenging problem because of the actuation principle, which is based on piezo-actuators with inherent nonlinear behavior. The major nonlinearities in the manipulator are identified
This paper presents a novel on-line approach of merging multiple different predictors of plasma glucose into a single optimized prediction. Various different predictors are merged by recursive weighting into a single prediction using regularized optimization. The approach is evaluated on 12 data sets of type I diabetes data, using three parallel predictors. The performance of the combined predicti
An L1 adaptive controller of piecewise constant type has been applied to a fighter aircraft by augmenting it to a linear state-feedback controller. Angle of attack and sideslip as well as velocity vector roll rate is demanded and controlled. It is relatively easy to design a controller augmentation this way; few parameters need to be tuned. To design an L1-controller for roll/pitch/yaw-motion of a
To fulfill increasing requirements in the manufacturing sector, companies are faced with several challenges. Three major challenges have been identified regarding time-to-market, vertical feedback loops and level of automation. Grafchart, a graphical language aimed for supervisory control applications, can be used from the process-planning phase, through the implementation phase and all the way to
When a feedback controller is implemented in a networked embedded system, the computations and communications induce delays and jitter, which may destabilize the control loop. The majority of previous work on analysis of control loops with time-varying delays has focused on output (actuation) jitter. In many embedded systems, input (sampling) jitter is also an issue. In this paper, we analyze the
In control theory there exist two convenient representations of a model, which are transfer functions and state-space matrices. However, structure in the transfer functions is not clearly seen in the state-space form, and on the other hand structure in the state-space form is not clearly seen in the transfer functions. The main reason for this is that Laplace transformation destroys most types of
Recently, several control systems for closed-loop anesthesia have been demonstrated both in simulation and clinical studies. A set of performance measures, proposed by Varvel et al., have constituted the standard means of comparing such systems. This paper debates the adequacy of the Varvel measures, as applied to closed-loop anesthesia, and proposes an alternative set of measures. Key features o
This paper proposes a transfer function parameter identification method, applicable to SISO systems of any order. Parameter identification is posed as a (non-convex) squared output error minimization problem, numerically solved utilizing Newton-Raphson iteration with back tracking line search. Focus lies on computing the cost function gradient and Hessian with respect to the parameter vector and o
The hypothesis of this thesis is that climate models should take structural vegetation changes that operate on interannual to centennial time scales into account in order to simulate climate change in a more realistic manner. To evaluate this hypothesis, a regional Earth System Model (ESM) has been developed, validated and applied over Europe. The model has enabled the identification of a number o
While Lars Norén’s confrontational and self-exposing En dramatikers dagbok (A Dramatist’s Journal, 2008) already has spurred discussions on the nature of confession in today’s mediatised literary public sphere, less has been said about the aesthetic project of the journal. By tracing this project back to Norén’s poetry of the 1960s as well as by comparing it to works by Lyn Hejinian and Kenneth Go
Separable Lyapunov functions play vital roles, for example, in stability analysis of large-scale systems. A Lyapunov function is called max-separable if it can be decomposed into a maximum of functions with one-dimensional arguments. Similarly, it is called sum-separable if it is a sum of such functions. In this paper it is shown that for a monotone system on a compact state space, asymptotic stab
In this paper, nonlinear model predictive control (NMPC) is applied to the start-up of a combined-cycle power plant. An object-oriented first-principle model library expressed in the high-level language Modelica has been written for the plant and used to set up the simulation and optimization models. The NMPC optimization problems are both encoded, using a high-level notation, and solved in the op
Popular Abstract in Swedish Esofagektomi (kirurgiskt avlägsnande av matstrupen) är ett omfattande ingrepp som främst utförs pga cancer, men som även utförs vid vissa godartade sjukdomar. Matstrupen sträcker sig från svalget, via bakre delen av bröstkorgen ned till övre delen av buken. Det anatomiska läget gör att man ur kirurgisk synpunkt oftast måste avlägsna matstrupen via en kombination av inciIn a prospective randomised study following oesophagectomy and gastric tube reconstruction patients with hand-sutured neck anastomoses were compared with patients with circular stapled chest anastomoses. The two groups had equal rates of anastomotic or conduit leaks of 7.3 % (3/41) and 7.1 % (3/42) and of benign anastomotic strictures of 19.5 % (8/41) and 28.6 % (12/42). Another prospective random
Autonomic computing was proposed as a promising solution to overcome the complexity of modern systems, which is causing management operations to become increasingly difficult for human beings. This work proposes the Adaptation Manager, a comprehensive framework to implement autonomic managers capable of pursuing some of the objectives of autonomic computing (i.e., self-optimization and self-healin
We derive an analytic solution to the problem of fixed-time trajectory generation with a quadratic cost function under velocity and acceleration constraints. This problem has a wide range of applications within motion planning. The advantage of the analytic solution compared to numerical optimization of the discretized problem is the unlimited resolution of the solution and the efficiency of the c
Purpose: We measured concentrations of human glandular kallikrein 2 (hK2), total prostate specific antigen (tPSA), free PSA (fPSA) and percent fPSA to evaluate their relationship to total prostate gland volume, benign prostatic hyperplasia (BPH) volume, total prostate cancer (PCa) volume (CaVol) and the volume of Gleason grades 4/5 cancer (CaVolG14) in the serum of 256 patients with PCa undergoing
OBJECTIVES: To evaluate the prophylactic efficacy of the human papillomavirus (HPV) quadrivalent vaccine in preventing low grade cervical, vulvar, and vaginal intraepithelial neoplasias and anogenital warts (condyloma acuminata). DESIGN: Data from two international, double blind, placebo controlled, randomised efficacy trials of quadrivalent HPV vaccine (protocol 013 (FUTURE I) and protocol 015 (F
We present a stopping condition to the duality based distributed optimization algorithm presented in [1] when used in a distributed model predictive control (DMPC) context. To enable distributed implementation, the optimization problem has neither terminal constraints nor terminal cost that has become standard in model predictive control (MPC). The developed stopping condition guarantees a prespec
