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Publications

2019

Consistent vehicle routing problem with service level agreements: A case study in the pharmaceutical distribution sector

Authors
Campelo, P; Neves Moreira, F; Amorim, P; Almada Lobo, B;

Publication
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH

Abstract
In this paper, a mathematical model is developed to tackle a Consistent Vehicle Routing Problem, which considers customers with multiple daily deliveries and different service level agreements such as time windows, and release dates. In order to solve this problem, an instance size reduction algorithm and a mathematical programming based decomposition approach are developed. This solution approach is benchmarked against a commercial solver. Results indicate that the method solves instances of large size, enabling its application to real-life scenarios. A case study in a pharmaceutical distribution company is analyzed. Consistent routes are planned for several warehouses, comprising hundreds of orders. A simulation model evaluates the performance of the generated route plans. Significant improvements in terms of the total distance traveled and the total travel times are obtained when compared to the company's current planning process.

2019

Phenolic composition of vine leaves infusions produced from different Portuguese and Spanish Vitis vinifera L. varieties

Authors
Jordao, AM; Sousa, J; Correia, AC; Valdes, ME; Nunes, FM; Cosme, F;

Publication
41ST WORLD CONGRESS OF VINE AND WINE

Abstract
The main object of the present study was to analyze the phenolic composition of vine leaves infusions prepared from 8 different Portuguese (Fernao Pires, Touriga Franca, Tinta Roriz, Encruzado, Touriga Nacional, Rufete, Baga, and Siria) and Spanish (Pardina, Cayetana, Garnacha, Ciguente, Eva, Tempranillo, Macabeo and Verdelho) Vitis vinifera L. varieties. In general, a wide range of phenolic content were obtained from the vine leaves infusions according to the vine variety used. Thus, for total phenolic content the values ranged from 18 to 37 mg/L for the infusions produced from Portuguese varieties, while for Spanish varieties the values ranged from 14 to 37 mg/L. Vine leaves infusions obtained from Touriga Franca and Pardina varieties showed the highest total phenolic content. As a consequence of phenolic composition, chromatic characteristics (L*, a* and b*) of vine leaves infusions were also analyzed. Finally, it was also detected different individual phenolic compounds, such as, coutaric acid, trans-caftaric acid, quercetin-3-O-glucoside, rutin and 3 different anthocyanins from the different vine leaves infusions. All of the results obtained in this work show that vine leaves infusion may be an interesting alternative source of phenolic compounds for human diet.

2019

Identifying Points of Interest and Similar Individuals from Raw GPS Data

Authors
Andrade, T; Gama, J;

Publication
CoRR

Abstract

2019

Knowledge Analysis Automatic Evaluation in Virtual Reality Immersive Experiences

Authors
Vieira, J; Nóbrega, R; Pereira, V; Coelho, A; Jacinto, A; Morais, C;

Publication
PROCEEDINGS OF THE 2019 INTERNATIONAL CONFERENCE ON GRAPHICS AND INTERACTION (ICGI 2019)

Abstract
Museums and exhibitions usually attempt to evaluate visitors' obtained knowledge through the use of traditional evaluation methods such as questionnaires. These are intrusive and may not provide correct results, especially due to the fact that visitors are usually not interested in being evaluated and may consider such questionnaires as intelligence tests. This paper proposes methods of design and creation of automatic evaluation techniques that make use of Virtual Reality (VR) in order to evaluate users' obtained knowledge after playing through a VR museum game experience. This Analysis System is non-intrusive (its methodology does not impact users' immersion and engagement), valid (can draw conclusions regarding users' obtained knowledge), and replicable (designed techniques can be used in a variety of experiences). Results indicate that the designed assessment techniques can be used to automatically evaluate the knowledge obtained by users throughout the experience, as well as some considerations to keep in mind when designing game experiences with these techniques.

2019

Wearable Glove Interaction with Robots

Authors
Ferreira, NMF; Silva, M; Santos, VDN; Santos, FM; Santos, JCB; Ferreira, JP;

Publication
2019 International Conference on Engineering Applications, ICEA 2019 - Proceedings

Abstract
This paper presents the exciting use of robotics to teach technologies in an approach that motivates the students through intuitive learning. MSc degree programme students are engaged in strong team-building, while developing and testing new algorithms for mobile robotics and electronics areas. This project endows students with intuitive learning, and experimental results revealed that the integration of skills allows the students to develop applications for real scenarios. In this work it is described an application to control with hand gestures, several differential driven robots. © 2019 IEEE.

2019

Production flow control through the use of reinforcement learning

Authors
Silva T.; Azevedo A.;

Publication
Procedia Manufacturing

Abstract
This paper introduces a new research focus for the problem of flow control. Most of the research until this point in this topic comes in the form of heuristics and flow control protocols, from which we can highlight Kanban and CONWIP. These protocols have as common ground the fact that both impact flow by limiting the amount of WIP (work in process) that circulates through a production route. These limits are not static in a sense that one limit defined for a given period will not suffice for all possible conditions the future may entail. Therefore, we need strategies to find which values for the WIP caps are best (according to an optimization target), given a production system state and a customer demand level. We propose the use of a Reinforcement learning (RL) agent and introduce the problem within the framework of a reinforcement learning problem, showing that for a simulated system it is possible to reduce WIP levels up to 43% without losses in throughput (TH). As an introduction to the flow control problem comparisons between push and pull systems are made resorting to the use of discrete event simulations. We simulated a CONWIP and a push protocol and comparisons are made in terms of cycle-time, throughput and customer lead-time. The work points-out that within the field of industrial management research terms such as cycle-time, customer lead-time, and lead-time are sometimes used interchangeably, which may lead to unnecessary confusion and hindered understanding of the subject matter. Specifically, we show that cycle-time reduction does not lead directly to customer lead-time reduction in a make to order environment.

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