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Publications

2020

Minimizing total earliness and tardiness in a nowait flow shop

Authors
Schaller, J; Valente, JMS;

Publication
INTERNATIONAL JOURNAL OF PRODUCTION ECONOMICS

Abstract
This paper considers the problem of scheduling jobs in a no-wait flow shop with the objective of minimizing total earliness and tardiness. An exact branch-and-bound algorithm is developed for the problem. Several dispatching heuristics used previously for other environments and two new heuristics were tested under a variety of conditions. It was found that one of the new heuristics consistently performed well compared to the others. An insertion search improvement procedure with speed up methods based on the structure of the problem was proposed and was found to deliver much improved solutions in a reasonable amount of time.

2020

Decision intelligence in street lighting management

Authors
Nunes, D; Teixeira, D; Carneiro, D; Sousa, C; Novais, P;

Publication
Advances in Intelligent Systems and Computing

Abstract
The European Union has been making efforts to increase energy efficiency within its member states, in line with most of the industrialized countries. In these efforts, the energy consumed by public lighting networks is a key target as it represents approximately 50% of the electricity consumption of European cities. In this paper we propose an approach for the autonomous management of public lighting networks in which each luminary is managed individually and that takes into account both their individual characteristics as well as ambient data. The approach is compared against a traditional management scheme, leading to a reduction in energy consumption of 28%. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2020.

2020

Preliminary assessment on the detection of putrescine using long period fiber gratings coated with titanium dioxide and poly(ethylene-co-vinyl acetate)

Authors
Vasconcelos, H; de Almeida, JMMM; Saraiva, C; Viveiros, D; Jorge, PAS; Coelho, L;

Publication
OPTICAL SENSING AND DETECTION VI

Abstract
Biogenic amines, such as putrescine are potential indicators of food storage condition and deterioration. The real time measurement of their concentration in food may become an important method of food control. It was found that putrescine diffuses through a thin layer made from a solution of Poly(ethylene-co-vinyl acetate) (PEVA) and maleic anhydride. Poly(ethylene-co-vinyl acetate) is a common non-chlorinated vinyl capable to adsorb specific analytes as putrescine which upon diffusion, reversibly binds to the maleic anhydride causing the polymer swelling resulting in spectral changes from the optical point of view. Long Period Fiber Gratings coated with 30 nm titanium dioxide, a high refractive index material used to increase the intrinsic sensitivity to the external refractive index, were overcoated with a thin layer of maleic anhydride doped Poly(ethylene-co-vinyl acetate). When exposed to solutions containing small concentrations of putrescine the resonant band corresponding to the LP1,6 cladding mode was found to move to shorter wavelengths. The observed blue shift corresponds to the increasing concentration of putrescine in the fiber sensor structure. Further work is being carried out to improve the sensitivity and the limit of detection of the sensing system as well as to increase range of operation, which is presently limited to 0.3 to 0.5 M. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

2020

Supplementary Damping Control Design for Large Scale PV Power Plant at Transmission Level Interconnection

Authors
Isbeih, YJ; El Moursi, MS; Lotfi, M; Catalão, JPS; Abdel Rahman, MH;

Publication
IEEE PES Innovative Smart Grid Technologies Europe, ISGT Europe 2020, Delft, The Netherlands, October 26-28, 2020

Abstract

2020

Understanding Service Design and Design Thinking Differences Between Research and Practice: An Empirical Study

Authors
Torres, A; Miranda, C;

Publication
EXPLORING SERVICE SCIENCE (IESS 2020)

Abstract

2020

AdaptPack Studio: an automated intelligent framework for offline factory programming

Authors
Castro, AL; de Souza, JPC; Rocha, LF; Silva, MF;

Publication
INDUSTRIAL ROBOT-THE INTERNATIONAL JOURNAL OF ROBOTICS RESEARCH AND APPLICATION

Abstract
PurposeThis paper aims to propose an automated framework for agile development and simulation of robotic palletizing cells. An automatic offline programming tool, for a variety of robot brands, is also introduced.Design/methodology/approachThis framework, named AdaptPack Studio, offers a custom-built library to assemble virtual models of palletizing cells, quick connect these models by drag and drop, and perform offline programming of robots and factory equipment in short steps.FindingsSimulation and real tests performed showed an improvement in the design, development and operation of robotic palletizing systems. The AdaptPack Studio software was tested and evaluated in a pure simulation case and in a real-world scenario. Results have shown to be concise and accurate, with minor model displacement inaccuracies because of differences between the virtual and real models.Research limitations/implicationsAn intuitive drag and drop layout modeling accelerates the design and setup of robotic palletizing cells and automatic offline generation of robot programs. Furthermore, A* based algorithms generate collision-free trajectories, discretized both in the robot joints space and in the Cartesian space. As a consequence, industrial solutions are available for production in record time, increasing the competitiveness of companies using this tool.Originality/valueThe AdaptPack Studio framework includes, on a single package, the possibility to program, simulate and generate the robot code for four different brands of robots. Furthermore, the application is tailored for palletizing applications and specifically includes the components (Building Blocks) of a particular company, which allows a very fast development of new solutions. Furthermore, with the inclusion of the Trajectory Planner, it is possible to automatically develop robot trajectories without collisions.

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