Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
Publications

Publications by CESE

2013

Keystrokes and clicks: Measuring stress on E-learning students

Authors
Rodrigues, M; Gonçalves, S; Carneiro, D; Novais, P; Fdez Riverola, F;

Publication
Advances in Intelligent Systems and Computing

Abstract
In traditional learning, teachers can easily get an insight into how their students work and learn and how they interact in the classroom. However, in online learning, it is more difficult for teachers to see how individual students behave. With the enormous growing of e-learning platforms, as complementary or even primary tool to support learning in organizations, monitoring students' success factors becomes a crucial issue. In this paper we focus on the importance of stress in the learning process. Stress detection in an E-learning environment is an important and crucial factor to success. Estimating, in a non-invasive way, the students' levels of stress, and taking measures to deal with it, is then the goal of this paper. Moodle, by being one of the most used e-learning platforms is used to test the log tool referred in this work. © Springer International Publishing Switzerland 2013.

2013

Multi-Layer Stream Mapping as a Combined Approach for Industrial Processes Eco-efficiency Assessment

Authors
Lourenço, EJ; Baptista, AJ; Pereira, JP; Dias-Ferreira, C;

Publication
Re-engineering Manufacturing for Sustainability

Abstract

2013

Multi-layer stream mapping as a combined approach for industrial processes eco-efficiency assessment

Authors
J. Lourenco, E; J. Baptista, A; P. Pereira, J; Dias Ferreira, C;

Publication
Re-Engineering Manufacturing for Sustainability - Proceedings of the 20th CIRP International Conference on Life Cycle Engineering

Abstract
Nowadays achieving sustainable development is a global concern. The issue of unsustainability can be related to population growth and excessive consumption of natural resources. To tackle these issues, several management tools and methodologies have been developed in the last years, to assess, analyse and improve the environmental and economic performance of production systems. This work presents an approach based value stream mapping in order to assess and improve energy efficiency, environmental performance and financial performance of a production system. The developed approach can be applied to any industry or production system, where all the unit processes involved are identified and the inputs/outputs of each unit system quantified and easily perceived. Key environmental performance indicators and the corresponding eco-efficiency ratios arise as outcomes of this approach, in which a Multi-Layer Stream Mapping (MSM) with visual management attributes is created.

2013

Trimming of 3D solid finite element meshes: sheet metal forming tests and applications

Authors
Barros, PD; Baptista, AJ; Alves, JL; Oliveira, MC; Rodrigues, DM; Menezes, LF;

Publication
Engineering with Computers

Abstract
Over the last years, the numerical simulation of integrated processes has become the major challenge in virtual try-out of sheet metal components, including trimming operations that may occur between forming steps. Detailed simulation of trimming processes is a challenging task, particularly when integrated with other forming operations such as deep drawing or hemming. A simplified approach can be adopted in which elements outside the trim surface are deleted from the finite element (FE) model adjusting the remaining to the surface. Following this approach, the state variables are mapped from the old FE mesh to the new trimmed mesh to continue the simulation. This paper addresses this simplified approach to the trimming process exploring a previously presented algorithm (Finite Elem Anal Des 42: 1053-1060, Baptista et al. 2006), which allows the treatment of hexahedral finite element meshes. Particularly, it focuses on the performance evaluation of the implemented strategies for correcting the FE mesh to the trimming surface, including the treatment of pentahedral-shaped elements. Different correction and treatment strategies are evaluated on different types of meshes, based on numerical simulation results of simple mechanical tests: uniaxial tensile test and simple bending test. Finally, two practical applications are given where the local effect of the trimming algorithm is highlighted. © 2013 Springer-Verlag London.

2012

Integrated resolution of assignment, sequencing and cutting problems in paper production planning

Authors
Correia, MH; Oliveira, JF; Soeiro Ferreira, JS;

Publication
INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH

Abstract
The integrated planning of several activities implicated in paper production can lead to remarkable gains in terms of raw materials and resource usage. However, activities such as order assignment, production sequencing and cutting planning are usually addressed separately while ignoring the interactions among these processes. But the quality of the solution resulting from the juxtaposition of the partial solutions is not guaranteed, and may have a significant impact in terms of inefficiency of global performance. This article considers production planning in a pulp and paper industry in order to meet a set of orders of diverse types of products, admitting the possibility of producing simultaneously in two or more paper machines with their own features. The developed approach, ASC-3Steps, considers not only cutting optimisation but also extends itself to the processes of assigning orders to paper machines and production sequencing at each machine. Minimisation of wasted paper is assumed to be the overall goal. A set of computational results based on real data is presented.

2012

Performance Measurement

Authors
Ferreira, PS; Cunha, PF; Maia Carneiro, L; Toscano, C;

Publication
Intelligent Non-hierarchical Manufacturing Networks - Poler/Intelligent Non-hierarchical Manufacturing Networks

Abstract

  • 162
  • 206