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Article
Publication date: 1 July 2006

Patricia Compañ, Rosana Satorre and Ramón Rizo

The aim is to obtain a dense and reliable disparity map from a stereoscopic pair under any luminosity condition. From the disparity map it is possible to obtain some information…

369

Abstract

Purpose

The aim is to obtain a dense and reliable disparity map from a stereoscopic pair under any luminosity condition. From the disparity map it is possible to obtain some information about the objects appearing in the scene, such as their position and their distance to the camera.

Design/methodology/approach

The disparity map is obtained using a correspondence method based on a multiresolution scheme. It also uses the simulated annealing algorithm to minimize the energy function, which integrates information coming from several sources: grey levels, non‐parametric transforms, edges and geometrical constraints. The multiresolution scheme allows us to interpolate the disparity map obtained in each level and to use it as an initial estimation for the simulating annealing process in the following level.

Findings

The multiresolution scheme speeds up the convergence. The fact of adding information about the neighbourhood improves the results. A simple and suitable energy function has been proposed. A simple efficient scaling scheme has been used. Their results are as good as other costly techniques such as block‐to‐point.

Research limitations/implications

The use of grey level images has the drawback that some bright areas can be confused. As a solution, some other additional features are proposed.

Originality/value

A new metric is proposed to evaluate the quality of a disparity map. A low‐cost energy function is proposed. It integrates several type information to add robustness to the method. The convergence of the method is dramatically speeded up reusing the results of the algorithm thanks to the multiresolution scheme.

Details

Kybernetes, vol. 35 no. 6
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 2 August 2013

María José Pujol, Francisco A. Pujol, Fidel Aznar, Mar Pujol and Ramón Rizo

In this paper the authors aim to show the advantages of using the decomposition method introduced by Adomian to solve Emden's equation, a classical non‐linear equation that…

100

Abstract

Purpose

In this paper the authors aim to show the advantages of using the decomposition method introduced by Adomian to solve Emden's equation, a classical non‐linear equation that appears in the study of the thermal behaviour of a spherical cloud and of the gravitational potential of a polytropic fluid at hydrostatic equilibrium.

Design/methodology/approach

In their work, the authors first review Emden's equation and its possible solutions using the Frobenius and power series methods; then, Adomian polynomials are introduced. Afterwards, Emden's equation is solved using Adomian's decomposition method and, finally, they conclude with a comparison of the solution given by Adomian's method with the solution obtained by the other methods, for certain cases where the exact solution is known.

Findings

Solving Emden's equation for n in the interval [0, 5] is very interesting for several scientific applications, such as astronomy. However, the exact solution is known only for n=0, n=1 and n=5. The experiments show that Adomian's method achieves an approximate solution which overlaps with the exact solution when n=0, and that coincides with the Taylor expansion of the exact solutions for n=1 and n=5. As a result, the authors obtained quite satisfactory results from their proposal.

Originality/value

The main classical methods for obtaining approximate solutions of Emden's equation have serious computational drawbacks. The authors make a new, efficient numerical implementation for solving this equation, constructing iteratively the Adomian polynomials, which leads to a solution of Emden's equation that extends the range of variation of parameter n compared to the solutions given by both the Frobenius and the power series methods.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 23 no. 6
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 1 April 2002

Pilar Arques, Patricia Compañ, Rafael Molina, Mar Pujol and Ramón Rizo

Segmentation is an important topic in computer vision and image processing. In this paper, we sketch a scheme for a multiscale segmentation algorithm and prove its validity on…

240

Abstract

Segmentation is an important topic in computer vision and image processing. In this paper, we sketch a scheme for a multiscale segmentation algorithm and prove its validity on some real images. We propose an approach to the model based on MRF (Markov Random Field) as a systematic way for integrating constraints for robust image segmentation. To do that, robust features and their integration in the energy function, which directs the process, have been defined. In this approach, the image is first transformed to different scales to determine which one fits better to our purposes. Then, it is segmented into a set of disjoint regions, the adjacent graph (AG) is determined and a MRF model is defined on the corresponding AG. Robust features are incorporated to the energy function by means of clique functions and optimal segmentation is then achieved by finding a labeling configuration that minimizes the energy function using Simulated Annealing.

Details

Kybernetes, vol. 31 no. 3/4
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 20 February 2007

Pilar Arques, Francisco A. Pujol, Faraón Llorens, Mar Pujol and Ramón Rizo

One of the main goals of vision systems is to recognize objects in real world to perform appropriate actions. This implies the ability of handling objects and, moreover, to know…

261

Abstract

Purpose

One of the main goals of vision systems is to recognize objects in real world to perform appropriate actions. This implies the ability of handling objects and, moreover, to know the relations between these objects and their environment in what we call scenes. Most of the time, navigation in unknown environments is difficult due to a lack of easily identifiable landmarks. Hence, in this work, some geometric features to identify objects are considered. Firstly, a Markov random field segmentation approach is implemented. Then, the key factor for the recognition is the calculation of the so‐called distance histograms, which relate the distances between the border points to the mass center for each object in a scene.

Design/methodology/approach

This work, first discusses the features to be analyzed in order to create a reliable database for a proper recognition of the objects in a scene. Then, a robust classification system is designed and finally some experiments are completed to show that the recognition system can be utilized in a real‐world operation.

Findings

The results of the experiments show that including this distance information improves significantly the final classification process.

Originality/value

This paper describes an object recognition scheme, where a set of histograms is included to the features vector. As is shown, the incorporation of this feature improves the robustness of the system and the recognition rate.

Details

Kybernetes, vol. 36 no. 1
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 17 April 2007

Francisco Gallego, Faraón Llorens, Mar Pujol and Ramón Rizo

The main intention of this paper is to state the benefits of using online videogames as a research environment, where AI algorithms are improved by means of learning from…

965

Abstract

Purpose

The main intention of this paper is to state the benefits of using online videogames as a research environment, where AI algorithms are improved by means of learning from real‐human‐behaviour examples.

Design/methodology/approach

The manner of taking advantage from the flux of real‐human‐behaviour examples inside an online videogame is stated. Then Mad University, a prototype online videogame specifically conceived and developed for this purpose, is explained.

Findings

Human‐like AI in artificial algorithms can be boosted by means of a specific kind of online videogame called MMORPGs, used as a research environment.

Research limitations/implications

Mad University is a prototype videogame which has been developed to experiment with AI algorithms that aim to learn strategies in a generalized fashion. The next research step will be to improve Mad University and to put it to work with hundreds of players and then research and test the effectiveness of the AI algorithms.

Originality/value

This paper proposes a new way of testing and experimenting with AI algorithms in order to obtain more human‐like results, and claims to have attempted to develop a generalized learning method.

Details

Kybernetes, vol. 36 no. 3/4
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 1 December 2003

Pilar Arques, Patricia Compañ, Rafael Molina, Mar Pujol and Ramon Rizo

In this work, we propose an approach to the model based on Markov random field (MRF) as a systematic way for integrating constraints for robust image segmentation. To do that…

251

Abstract

In this work, we propose an approach to the model based on Markov random field (MRF) as a systematic way for integrating constraints for robust image segmentation. To do that, robust features and their integration in the energy function, which directs the process, have been defined. The suitability of the method has been verified by comparing classic features with the robust ones. In this approach, the image is first segmented into a set of disjoint regions and the adjacent graph (AG) has been determined. This approach is applied by defining an MRF model on the corresponding AG. Robust features are incorporated to the energy function by means of clique functions, and optimal segmentation is then achieved by finding a labelling configuration, which minimizes the energy function using the simulated annealing.

Details

Kybernetes, vol. 32 no. 9/10
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 29 April 2021

Simone Pizzi, Rossella Leopizzi and Andrea Caputo

This study aims to investigate the evolutionary pathways adopted by a digital platform to favor the development of an entrepreneurial ecosystem inspired by circular economy…

1462

Abstract

Purpose

This study aims to investigate the evolutionary pathways adopted by a digital platform to favor the development of an entrepreneurial ecosystem inspired by circular economy behaviors, becoming an enabler in the development of a coevolutionary relationship between entrepreneurial ecosystems and circular economy.

Design/methodology/approach

An in-depth single-case study method has been applied, investigating the case of circularity.com, the first and only circular economy industrial symbiosis platform in Italy.

Findings

The paper shows how digital platforms can transition towards circular business models, particularly for small and medium enterprises (SMEs). Moreover, the findings show how sustainable platforms' need to revise their business models to effectively engage with stakeholders. The analysis also shows the central role covered by entrepreneurial ecosystems in the transition towards a more circular and sustainable business models.

Originality/value

This paper contributes to theoretical development by offering new and insightful explanations of firms' behavior and coevolution, moving beyond the classic interpretation of industry dynamics and analyzing a unique case study. This study has implications for both practice and research, as it offers a better and more holistic understanding of the enabling role of digital platforms for a circular economy.

Details

Management of Environmental Quality: An International Journal, vol. 33 no. 1
Type: Research Article
ISSN: 1477-7835

Keywords

Available. Open Access. Open Access
Article
Publication date: 3 July 2023

Siraj Ahmed, Jukka Majava and Kirsi Aaltonen

The purpose of this study is to investigate the benefits and challenges of implementing circular economy (CE), as well as shed light on the influence of procurement strategy in CE…

5258

Abstract

Purpose

The purpose of this study is to investigate the benefits and challenges of implementing circular economy (CE), as well as shed light on the influence of procurement strategy in CE implementation in construction projects.

Design/methodology/approach

A qualitative research approach with abductive reasoning was adopted. The empirical data were collected from the construction industry in the United Arab Emirates (UAE).

Findings

The results reveal that clients, consultants and contractors have limited awareness, knowledge and motivation to implement CE in construction projects. The absence of incentives to design projects following CE principles, lack of involvement of contractors and suppliers, non-use of materials that use CE principles and current procurement strategies are the main challenges for the implementation of CE in the UAE.

Originality/value

Previous research offers limited knowledge on CE and its implementation in construction projects particularly from a procurement strategy perspective. The findings of the study provide new knowledge of the benefits, challenges and role of procurement strategy for implementing CE. It is suggested that collaborative and partnering-based procurement methods are needed to facilitate the effective implementation of CE.

Details

Construction Innovation , vol. 24 no. 7
Type: Research Article
ISSN: 1471-4175

Keywords

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