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The calendar disk of the fifteenth century astronomical clock in the church of Saint Mary in Gdansk (Poland) contains a wealth of astronomical and calendrical data. We make a statistical analysis of the mean conjunction times of all the mean New Moons as represented on the disk for four Metonic 19-year cycles. We find that the conjunction times were generated using the Alfonsine value for the leng
This book brings together several outstanding authors in the field and covers questions relating to the fundamental milestones in technology development and governance (Judit Sandor), an analysis of disability questions and empowerment of the community (Pin Lean Lau), right to health opportunities and challenges (Anne Kjersti Befring), the protection of the right to private life and life (Merel M.
This research-praxis think-piece presents some wry musings from recent experience in Uganda attempting to bridge the research-practice interface and share research findings in the context of small African towns. It is written from the perspective of a recent doctoral graduate in a light-hearted but enquiring manner, with sometimes humorous, sometimes frustrated, reflections on the ethical/practica
Abstract in Chinese年韩国总统选举中, 获胜候选人所属的政党几年前还毫无机会，但竞选角逐为何如此激烈？我们将选举置于民主和反民主力量的较量的背景中考察就能得到答案。反民主势力通过玩世不恭地诋毁政治来竞逐权力。对这种玩世不恭情绪如何在2016到2022年期间——但同时也在更深远的历史背景之下——如何演进的考察既表明了这次大选的利害攸关之处，也揭示了反民主力量的代表人物用以制造出选票差距的方法。Why was South Korea’s 2022 presidential election so close, when only a few years prior the party of the winning candidate had been out of contention? The answer can be found by situating the election against a battle between democratic and anti-democratic forces. Anti-democratic forces cynically bid for power by denigrating politics. An examination of how this cynical sensibility developed, from 2
This article contains a continuous-time optimal and adaptive control scheme for underwater vehicles moving in six degrees of freedom. The control scheme is an extension of the algorithm in Johansson (1990). The algorithm is optimal in the sense that it minimizes the state errors and the forces which contributes to the vehicle’s kinetic energy that is spend to correct these errors. The performance
To further clarify the mechanisms maintaining chronic atrial fibrillation (CAF). a method for system identification of activation patterns of the atria was developed. Data were obtained as repeated recordings of 8 s duration, each of 56 atrial bipolar electrograms, simultaneously acquired during open-heart surgery at multiple sites in the right atrial free wall in 12 patients with stable sinus rhy
This paper presents theory for extension of the Yakubovich-Kalman-Popov (YKP) lemma for stability analysis relevant for observer-based feedback control systems. We show that minimality is not necessary for existence of Lur'e-Lyapunov functions. Implications for output feedback stabilization, positivity, factorization and passivity are given.
OBJECTIVE: Low-level viraemia (LLV) occurs in some people with HIV (PWH) receiving antiretroviral therapy (ART) and has been linked to inferior treatment outcomes. We investigated factors associated with LLV in a nationwide cohort of Swedish PWH starting ART.METHODS: Participants were identified from the InfCareHIV register, with the following inclusion criteria: ART initiation 2006-2017, age >15
Today most industrial robot systems use dedicated and rather limited sensors, and available control systems provide limited support for feedback control. Aiming towards more autonomous robot systems, we want to improve flexibility. The game Scrabble is used as a test problem capturing these aspects. Our approach is to incorporate visual servoing and a conventional powerful off-line prograrnrning (
Homogeneous Charge Compression Ignition (HCCI) is a promising but challenging combustion engine concept. The potential for good fuel economy and low emissions is high but the transient performance required for automotive applications presents a few problems still to be solved. The focus of this work is identification of the process dynamics. An ARX type model is fitted to input-output data. A meth
The General Data Protection Regulation (GDPR) establishes a right for individuals to get access to information about automated decision-making based on their personal data. However, the application of this right comes with caveats. This paper investigates how European insurance companies have navigated these obstacles. By recruiting volunteering insurance customers, requests for information about
We study an image-based visual servoing system implemented on a non-dedicated network with non-deterministic computational nodes. A problem is that time delays are typically non-deterministic and variable and may cause significant degradation of control system performance, stability and robustness if not compensated for. Another problem is the presence of noise due to information loss and measurem
This paper presents theory for stability analysis and design for a class of observer-based feedback control systems. Relaxation of the controllability and observability conditions imposed in the Yakubovich-Kalman-Popov (YKP) lemma can be made for a class of nonlinear systems described by a linear time-invariant system (LTI) with a feedback-connected cone-bounded nonlinear element. It is shown how
Homogeneous Charge Compression Ignition (HCCI) combustion lacks direct ignition timing control, instead the auto ignition depends on the operating condition. Since auto ignition of a homogeneous mixture is very sensitive to operating condition a fast combustion timing control is necessary for reliable operation, the ignition timing control design requiring appropriate models and system output vari
The paper suggests a method for compensating the impact of friction for the control nonlinear systems, where the original controller (derived without taking into account friction) results from the passivity relation. The illustrative example is given.
System identification of continuous-time model based on discrete-time data can be performed using a algorithm combining linear regression and LQG-balanced model reduction. The approach is applicable also to unstable system dynamics and it provides balanced models for optimal linear prediction and control.
Asthma and rhinitis often co-exist in the same patient. Although some authors observed a higher prevalence and/or greater severity of asthma in patients with rhinitis, this view is not homogeneous and the debate continues. The aim of our study is to describe the prevalence of rhinitis in children and adolescents and to analyse their relationship with the prevalence of asthma. A multicentre study w
