Search results for " CRA"

Evaluating a Future Remote Control Environment with an Experience-Driven Science Fiction Prototype

2015

The case study presented in this paper aimed at discovering opportunities for ambient intelligence and new interaction methods for a future remote crane-operating environment. The theoretical objective was to carry out an experience-driven research project in an industrial work context, and the practical objective was to create and evaluate a future oriented science fiction prototype. The work was carried out in close co-operation with an industrial partner who was a domain expert in the field of crane industry. The aim was to focus on clearly defined user experience goals to which the industrial partner committed. The consequent immediate objective was to focus on two explicit experiences …

Application of Model Predictive Control in Discrete Displacement Cylinders to Drive a Knuckle Boom Crane

2018

In this paper, two Discrete Displacement Cylinders (DDCs) are used to drive the boom of a knuckle boom crane. DDCs operate by connecting one of several available pressure levels to each chamber in order to produce different forces. A trade-off exists with such systems, between the accuracy of tracking and energy dissipation due to switching. A popular way to approach this problem is a Force Shifting Algorithm (FSA). However, in this paper, the trade-off is managed by use of a Model Predictive Control (MPC) algorithm. The tracking accuracy and energy efficiency of the MPC and FSA strategies for DDCs are compared to a PID strategy for standard cylinders. The comparison is obtained by use of a…

Esse.Re (nel) mondo. Arti visive e rinascita dal 1966 a oggi

2022

Nel complesso quadro distopico della pandemia il saggio prende in esame il progetto espositivo e curatoriale .RE, mostra che non si limita a presentare le ricerche di una selezione di artisti tra i più influenti dei nostri tempi ma si focalizza sull’urgente necessità di problematizzare le dicotomie arte/vita, azione/contemplazione, arte/anti-arte, nella prospettiva di una riflessione critica intorno a una raccolta di opere innovative, tanto nel metodo quanto nel contenuto. Vengono esaminate le opere più significative delle ricerche condotte da Alberto Burri, Saint Clair Cemin, Tony Cragg, Zang Hong Mei, Anselm Kiefer, Jeff Koons, Sol LeWitt, Emil Lukas, Mimmo Paladino, Claudio Parmiggiani, …

Fuzzy logic approach to predict vehicle crash severity from acceleration data

2015

Vehicle crash is a complex behavior to be investigated as a challenging topic in terms of dynamical modeling. On this aim, fuzzy logic can be utilized to analyze the crash dynamics rapidly and simply. In this paper, the experimental data of the frontal crash is recorded using an accelerometer located at the centre of the gravity of the vehicle. The acceleration signal was the raw data from which the collision intensity expressed by the kinetic energy and the jerk were derived. The fuzzy logic model was then developed from the two inputs namely kinetic energy and jerk. The output variable is the crash severity expressed as the dynamic crash. The result shows that the jerk contributes much to…

Development of Point-to-Point Path Control in Actuator Space for Hydraulic Knuckle Boom Crane

2020

This paper presents a novel method for point-to-point path control for a hydraulic knuckle boom crane. The developed path control algorithm differs from previous solutions by operating in the actuator space instead of the joint space or Cartesian space of the crane. By operating in actuator space, almost all the parameters and constraints of the system become either linear or constant, which greatly reduces the complexity of both the control algorithm and path generator. For a given starting point and endpoint, the motion for each actuator is minimized compared to other methods. This ensures that any change in direction of motion is avoided, thereby greatly minimizing fatigue, jerky motion,…

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…

Tracking Formation of a Lava Lake From Ground and Space: Masaya Volcano (Nicaragua), 2014-2017

2018

A vigorously degassing lava lake appeared inside the Santiago pit crater of Masaya volcano (Nicaragua) in December 2015, after years of degassing with no (or minor) incandescence. Here we present an unprecedented-long (3 years) and continuous volcanic gas record that instrumentally characterizes the (re)activation of the lava lake. Our results show that, before appearance of the lake, the volcanic gas plume composition became unusually CO 2 rich, as testified by high CO 2 /SO 2 ratios (mean: 12.2 ± 6.3) and low H 2 O/CO 2 ratios (mean: 2.3 ± 1.3). The volcanic CO 2 flux also peaked in November 2015 (mean: 81.3 ± 40.6 kg/s; maximum: 247 kg/s). Using results of magma degassing models and budg…

Novel Imidazolium Based Catalyst for the Chemical Fixation of Carbon Dioxide

2015

An efficient proposal for the application of simulated annealing algorithms

2014

Complex nonlinear optimization problems require specific resolution techniques. These problems are often characterized by a solution space that presents many local optima. In these cases, local search algorithms, as the classical descent neighborhood search method, have a heavy drawback: the optimization algorithm generally converges towards a local minimum. To avoid getting trapped in a local minimum, the optimization algorithm must allow to accept worse solutions than the current one. Several kinds of algorithms have been ideated for this purpose and they differ for the acceptance criteria of a pejorative solution. Among such algorithms it is possible to remember the Taboo Search (TS) and…

Hemocyanin conformational changes associated with SDS-induced phenol oxidase activation.

2007

The enzymatic activity of phenoloxidase is assayed routinely in the presence of SDS. Similar assay conditions elicit phenoloxidase activity in another type 3 copper protein, namely hemocyanin, which normally functions as an oxygen carrier. The nature of the conformational changes induced in type 3 copper proteins by the denaturant SDS is unknown. This comparative study demonstrates that arthropod hemocyanins can be converted from being an oxygen carrier to a form which exhibits phenoloxidase activity by incubation with SDS, with accompanying changes in secondary and tertiary structure. Structural characterisation, using various biophysical methods, suggests that the micellar form of SDS is …