2013
Autores
Gregorio Ramos, PAG;
Publicação
INTERNATIONAL JOURNAL OF ADVANCED ROBOTIC SYSTEMS
Abstract
Geostatistics has been successfully used to analyse and characterize the spatial variability of environmental properties. Besides providing estimated values at unsampled locations, geostatistics measures the accuracy of the estimate, which is a significant advantage over traditional methods used to assess pollution. This work uses universal block kriging to model and map the spatial distribution of salinity measurements gathered by an Autonomous Underwater Vehicle in a sea outfall monitoring campaign. The aim is to distinguish the effluent plume from the receiving waters, characterizing its spatial variability in the vicinity of the discharge and estimating dilution. The results demonstrate that geostatistical methodology can provide good estimates of the dispersion of effluents, which are valuable in assessing the environmental impact and managing sea outfalls. Moreover, since accurate measurements of the plume's dilution are rare, these studies may be very helpful in the future to validate dispersion models.
2013
Autores
Homayouni, SM; Tang, SH;
Publicação
MATHEMATICAL PROBLEMS IN ENGINEERING
Abstract
According to previous researches, automated guided vehicles and quay cranes in container terminals have a high potential synergy. In this paper, a mixed integer programming model is formulated to optimize the coordinated scheduling of cranes and vehicles in container terminals. Objectives of the model are to minimize total traveling time of the vehicles and delays in tasks of cranes. A genetic algorithm is developed to solve the problem in reasonable computational time. The most appropriate control parameters for the proposed genetic algorithm are investigated in a medium size numerical test case. It is shown that balanced crossover and mutation rates have the best performance in finding a near optimal solution for the problem. Then, ten small size test cases are solved to evaluate the performance of the proposed optimization methods. The results show the applicability of the genetic algorithm since it can find near optimal solutions, precisely and accurately.
2013
Autores
Dehghanian, N; Homayouni, SM;
Publicação
2013 13TH IRANIAN CONFERENCE ON FUZZY SYSTEMS (IFSC)
Abstract
Job shop scheduling problem (JSP) with sequence-dependent setup time and re-entrant work flows is considered in this paper. This is an NP-hard problem which needs to be solved using (meta)heuristic methods (e.g. genetic algorithm (GA)), especially for relatively large instances. However, the GA may face premature convergence (i.e. converging to a local optima), especially for rough solution spaces. In this paper, a fuzzy genetic algorithm (FGA) is proposed to overcome this issue. The objective is to minimize makespan of such problem. Research results show that the FGA outperforms the standard GA and offers better solutions in the same number of runs. © 2013 IEEE.
2013
Autores
Castano, JDM; Moreira, MRA; Sousa, PSA; Meneses, RFC;
Publicação
EXPLORING SERVICES SCIENCE, IESS 2013
Abstract
In this research we represent the major elements of the Theory of Constraints (TOC) in a services environment, specifically for the banking sector, and we analyze the factors involved in the decision to adopt the TOC by companies in this sector. It was identified that the four elements of the TOC theory, throughput, inventory, operating expenses and constraints, correspond to, respectively, the money coming from financial services rendered, the money required to generate this profit, the money to fund the expenses, and the limitations to the normal activity. Regarding the constraints, the most common are mainly administrative (regulations and policies) and the lack of technological resources associated to the scarcity of capital flow and the environment imposed by the state of the economy at a specific time. The main factors that influence the decision to adopt the TOC by the banking sector reside, first, in the tool's current level of development; second, in the nature and the characteristics of the banking service that are very far from the original industrial reality and, finally, in organizational factors such as the attitude towards change, the leadership of the administration and the commitment of the entire institution.
2013
Autores
Moreira, MRA; Maia, MAS; Sousa, PSA; Meneses, RFC;
Publicação
EXPLORING SERVICES SCIENCE, IESS 2013
Abstract
Globalization has created countless opportunities for the internationalization of a wide range of services. Recent technological innovations associated with the reduction or elimination of trade barriers, resulted in an exponential expansion of service firms. This paper analyzes the internal and external factors that influence the decision to operate internationally. The hypotheses are empirically examined through a survey sent to 322 firms from the design, architecture and engineering sector. Multivariate analysis is used to ascertain the main determinants of internationalization in these firms. The findings indicate that the main reasons underlying the internationalization of these service firms are the size of the firm, the competitive environment and the staff's degree of international experience. These factors, which influence the management's attitudes toward operating internationally, determine the firm's degree of internationalization. Moreover, firms that have a high number of senior managers with a graduate course and higher skills in foreign languages are more prone to internationalize. Some practical implications are presented for service firms that are in the process of internationalizing.
2013
Autores
Coelho, DC; Meneses, RFC; Moreira, MRA;
Publicação
EXPLORING SERVICES SCIENCE, IESS 2013
Abstract
A growth of the market share of private label brands has been observed in developed countries. This growth was initially confirmed for food and drugstore categories, but it quickly expanded to new product categories, particularly technology products. This study focus on a specific technology segment - the private label brands in smartphones, due to the growth observed in its demand, in recent years. In this context, we analyzed and studied the smartphone market and consumer, and examine the factors influencing purchase intention of private label smartphones. The literature review on private label technological products proved to be scarce, which raised a challenge in exploring the main differences among factors influencing purchase intention for this specific product category. In this study, through the development and application of an analytical model, we test a set of variables that resulted from the literature review, which could potentially influence the purchase intention of smartphones. We applied a questionnaire to a study population, and recorded 339 valid answers. The results were estimated in accordance with the Structural Equation Model. Our analysis highlights the importance given to technology by consumers, as well as price and quality. This study also revealed the importance of private label brands in a market which has as yet been underexplored.
The access to the final selection minute is only available to applicants.
Please check the confirmation e-mail of your application to obtain the access code.