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This paper studies the properties of the zeros of sampled-data systems. Since the basic study by Åström et al. that showed there can exist unstable zeros that have no relevance to the original continuous-time plant, there have been various studies that circumvent this effect by introducing various techniques. The present paper studies zeros of sampled-data systems from the standpoint of lifting. W
Relay autotuning has proven very successful for single-input single-output systems. This paper proposes an identification method for relay autotuning of systems with two inputs and two outputs (TITO systems). The combination of asymmetric relay feedback and output error identification admits short tuning time, without the need for limit cycle convergence. The method is successfully demonstrated on
Control and scheduling co-design becomes an issue when several controller tasks share the same execution platform and disrupt the ideal sampling and actuation patterns. In co-design the objective is to optimize the combined performance of all the controllers on the platform, subject to schedulability constraints. In the paper four LQG-based co-design methods are reviewed and evaluated: delay-aware
The paper presents conditions for the stability of a dynamical network described by a directed graph, whose nodes represent dynamical systems characterised by the same transfer function F(s) and whose edges account for the interactions between pairs of nodes. In turn, these interactions depend via a transference G(s) on the outputs of the subsystems associated with the connected nodes. The stabili
This paper presents new simple tuning rules for the gain in feedforward compensators. When the ideal feedforward controller is not possible to implement, a negative effect is introduced in the closed-loop response. So, the closed-loop transfer function from the disturbance to the error is analyzed and tuning rules for the feedforward gain are proposed. Two feedforward structures are used, a lead-l
Purpose: The purpose of this paper is to explore how global operations of manufacturing companies influence the choice of product architecture decisions, ranging from integral to modular product designs. Design/methodology/approach: The authors perform a multiple-case study of three global manufacturing companies with integral and modular product architectures. Findings: The authors find that the
Self-assembly of block copolymers (BCPs) provides an attractive nanolithography approach, which looks especially promising for fabrication of regular structures with characteristic sizes below 10 nm. Nevertheless, directed self-assembly (DSA) and pattern transfer for BCPs with such small features remain to be a challenge. Here we demonstrate DSA of the maltoheptaose-block-polystyrene (MH1,2k-b-PS4
Methods for detecting depression in fathers after the birth of their child are scarce. The Edinburgh Postnatal Depression Scale (EPDS), used to screen mothers for postpartum depression (PPD), lacks somatization and externalizing items. This potentially decreases its sensitivity in detecting depression in fathers, as many men actually express depression with somatization or externalizing symptoms.
Streptococcus pyogenes of the M1 serotype is commonly associated with invasive streptococcal infections and development of streptococcal toxic shock syndrome. The M1 protein is a powerful inducer of inflammatory responses for several human cell types, but the reason why M1 protein-related strains is over-represented in invasive streptococcal diseases is still not understood. This study was underta
During and after deglaciation, Lake Vättern developed from a proglacial lake situated at the westernmost rim of the Baltic Ice Lake (BIL), into a brackish water body connecting the North Sea and the Baltic Sea, and finally into an isolated freshwater lake. Here we present geochemical and mineralogical data from a 70-m composite sediment core recovered in southern Lake Vättern. Together with a radi
Frataxin is a highly conserved protein found in both prokaryotes and eukaryotes. It is involved in several central functions in cells, which include iron delivery to biochemical processes, such as heme synthesis, assembly of iron-sulfur clusters (ISC), storage of surplus iron in conditions of iron overload, and repair of ISC in aconitase. Frataxin from different organisms has been shown to undergo
I kapitlet diskuteras de styrningsideal som råder i kommunal verksamhet och hur dessa påverkats av New Public Management – den styrningsfilosofi som växte sig stark under 1990-talet och i början av 2000-talets första decennium. Ramberg noterar dels det märkliga i att styrverktyg utvecklade för att hantera företagsvärldens utmaningar alls prövas i kommunal verksamhet, dels det anmärkningsvärda i at
We suggest a seven-grade model for the evolution of causal cognition as a framework that can be used to gauge variation in the complexity of causal reasoning from the panin-hominin split until the appearance of cognitively modern hunter-gatherer communities. The intention is to put forward a cohesive model for the evolution of causal cognition in humans, which can be assessed against increasingly
Keeping pigs in urban and peri-urban areas may not only provide many benefits for the urban households, but may also be challenging and a potential health hazard. The aim of this cross-sectional study was to describe household characteristics and to evaluate perceived benefits and constraints among pig-keepers in the urban and peri-urban areas of Phnom Penh, Cambodia. The study included 204 househ
