Search results for "Electronic computers. Computer science"
showing 10 items of 185 documents
Computing Euclidean Steiner trees over segments
2020
In the classical Euclidean Steiner minimum tree (SMT) problem, we are given a set of points in the Euclidean plane and we are supposed to find the minimum length tree that connects all these points, allowing the addition of arbitrary additional points. We investigate the variant of the problem where the input is a set of line segments. We allow these segments to have length 0, i.e., they are points and hence we generalize the classical problem. Furthermore, they are allowed to intersect such that we can model polygonal input. As in the GeoSteiner approach of Juhl et al. (Math Program Comput 10(2):487–532, 2018) for the classical case, we use a two-phase approach where we construct a superse…
Experimental System Identification and Black Box Modeling of Hydraulic Directional Control Valve
2015
Directional control valves play a large role in most hydraulic systems. When modeling the hydraulic systems, it is important that both the steady state and dynamic characteristics of the valves are modeled correctly to reproduce the dynamic characteristics of the entire system. In this paper, a proportional valve (Brevini HPV 41) is investigated to identify its dynamic and steady state characteristics. The steady state characteristics are identified by experimental flow curves. The dynamics are determined through frequency response analysis and identified using several transfer functions. The paper also presents a simulation model of the valve describing both steady state and dynamic charac…
Analysis of Offshore Knuckle Boom Crane - Part Two: Motion Control
2013
In this paper design of electro-hydraulic motion control systems for offshore knuckle boom cranes is discussed. The influence of the control valve bandwidth along with the ramp time for the control signal are investigated both analytically with simplified system models and numerically with an experimentally verified crane model. The results of both types of investigations are related to general design rules for selection of control valves and ramp times and the relevance of these design rules is discussed. Generally, they are useful but may be too conservative for offshore knuckle boom cranes. However, as demonstrated in the paper, the only proper way to determine this is to evaluate the mo…
A Playful Experiential Learning System With Educational Robotics
2020
This article reports on two studies that aimed to evaluate the effective impact of educational robotics in learning concepts related to Physics and Geography. The reported studies involved two courses from an upper secondary school and two courses from a lower secondary school. Upper secondary school classes studied topics of motion physics, and lower secondary school classes explored issues related to geography. In each grade, there was an “experimental group” that carried out their study using robotics and cooperative learning and a “control group” that studied the same concepts without robots. Students in both classes were subjected to tests before and after the robotics laboratory, to c…
Big Data as a Driver for Clinical Decision Support Systems: A Learning Health Systems Perspective
2018
Big data technologies are nowadays providing health care with powerful instruments to gather and analyze large volumes of heterogeneous data collected for different purposes, including clinical care, administration, and research. This makes possible to design IT infrastructures that favor the implementation of the so-called “Learning Healthcare System Cycle,” where healthcare practice and research are part of a unique and synergic process. In this paper we highlight how “Big Data enabled” integrated data collections may support clinical decision-making together with biomedical research. Two effective implementations are reported, concerning decision support in Diabetes and in Inherited Arrh…
XML document-grammar comparison: related problems and applications
2011
10.2478/s13537-011-0005-1; International audience; XML document comparison is becoming an ever more popular research issue due to the increasingly abundant use of XML. Likewise, a growing interest fosters the development of XML grammar matching and comparison, due to the proliferation of heterogeneous XML data sources, particularly on the Web. Nonetheless, the process of comparing XML documents with XML grammars, i.e., XML document and grammar similarity evaluation, has not yet received the attention it deserves. In this paper, we provide an overview on existing research related to XML document/grammar comparison, presenting the background and discussing the various techniques related to th…
Chapter 4</br>Will our children have the chance to do research on today’s digital books?
2016
In this chapter, I will first position my considerations about the sustainability of ebooks for future research in the context of book history; moreover, I will introduce basic concepts of (migration and emulation) as well as challenges to the long-term preservation of digital data in greater generality. After that and taking current research on past (printed) books as an analogy, I shall try to outline which kinds of (digital) material will be indispensable in the future to do research on today's digital book production: published digital materials and unique (digital) artefacts. Finally, I shall present the results of my exemplary studies to find out which precautions for the future avail…
SEAI: Social Emotional Artificial Intelligence Based on Damasio’s Theory of Mind
2018
A socially intelligent robot must be capable to extract meaningful information in real-time from the social environment and react accordingly with coherent human-like behaviour. Moreover, it should be able to internalise this information, to reason on it at a higher abstract level, build its own opinions independently and then automatically bias the decision-making according to its unique experience. In the last decades, neuroscience research highlighted the link between the evolution of such complex behaviour and the evolution of a certain level of consciousness, which cannot leave out of a body that feels emotions as discriminants and prompters. In order to develop cognitive systems for s…
Design of Wideband MIMO Car-to-Car Channel Models Based on the Geometrical Street Scattering Model
2012
Published version of an article in the journal: Modelling and Simulation in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2012/264213 Open access We propose a wideband multiple-input multiple-output (MIMO) car-to-car (C2C) channel model based on the geometrical street scattering model. Starting from the geometrical model, a MIMO reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. The proposed channel model assumes an infinite number of scatterers, which are uniformly distributed in two rectangular areas located on both sides of the street. Analytical solutions a…
Analysis of Offshore Knuckle Boom Crane - Part One: Modeling and Parameter Identification
2013
This paper presents an extensive model of a knuckle boom crane used for pipe handling on offshore drilling rigs. The mechanical system is modeled as a multi-body system and includes the structural flexibility and damping. The motion control system model includes the main components of the crane's electro-hydraulic actuation system. For this a novel black-box model for counterbalance valves is presented, which uses two different pressure ratios to compute the flow through the valve. Experimental data and parameter identification, based on both numerical optimization and manual tuning, are used to verify the crane model. The demonstrated modeling and parameter identification techniques target…