2014
Autores
Homayouni, SM; Tang, SH; Motlagh, O;
Publicação
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
Abstract
Commonly in container terminals, the containers are stored in yards on top of each other using yard cranes. The split-platform storage/retrieval system (SP-AS/RS) has been invented to store containers more efficiently and to access them more quickly. The integrated scheduling of quay cranes, automated guided vehicles and handling platforms in SP-AS/RS has been formulated and solved using the simulated annealing algorithm in previous literatures. This paper presents a genetic algorithm (GA) to solve this problem more accurately and precisely. The GA includes a new operator to make a random string of tasks observing the precedence relations between the tasks. For evaluating the performance of the GA, 10 small size test cases were solved by using the proposed GA and the results were compared to those from the literature. Results show that the proposed GA is able to find fairly near optimal solutions similar to the existing simulated annealing algorithm. Moreover, it is shown that the proposed GA outperforms the existing algorithm when the number of tasks in the scheduling horizon increases (e.g. 30 to 100).
2014
Autores
Moreira, MRA; Castano, JDM; Sousa, PSA; Meneses, RFC;
Publicação
Periodica Polytechnica, Social and Management Sciences
Abstract
This paper describes the major elements of the Goldratt's framework - the Theory of Constraints (TOC) - in the banking sector, and examines the factors involved in the decision to adopt the TOC by companies in this sector. Through a deep literature review, analyzing similar cases that apply the Goldratt's framework in services and in manufacturing and the several views of its components, we aim at formulating a framework specifically for the banking system. The study uses a qualitative methodology supported by the information extracted from reality as it is framed in a multi-case study model. As part of the quantitative approach, we test several research hypotheses raised from the review of existing studies in the area. The main factors that influence the decision to adopt the TOC are the nature and the characteristics of the banking service, the attitude towards change, the leadership and the commitment of the entire institution. By using the Goldratt's approach outlined in this article, through the location of the constraints and develop practical measurement to facilitate the banking process improvements, banks can improve resource utilization, revenues and employee satisfaction.
2014
Autores
Ferreira, L; Putnik, G; Cruz Cunha, MM; Putnik, Z; Castro, H; Alves, C; Shah, V;
Publicação
International Journal of Web Portals
Abstract
The real Cloud and Ubiquitous Manufacturing systems require effectiveness and permanent availability of resources, their capacity and scalability. One of the most important problems for applications management over cloud based platforms, which are expected to support efficient scalability and resources coordination following SaaS implementation model, is their interoperability. Even application dashboards need to easily incorporate those new applications, their interoperability still remains a big problem to override. So, the possibility to expand these dashboards with efficiently integrated communicational cloud based services (cloudlets) represents a relevant added value as well as contributes to solving the interoperability problem. Following the architecture for integration of enriched existing cloud services, as instances of manufacturing resources, this paper: a) proposes a cloud based web platform to support dashboard integrating communicational services, and b) describe an experimentation to sustain the theory that the effective and efficient interoperability, especially in dynamic environments, could be achieved only with human intervention. Copyright © 2014, IGI Global.
2014
Autores
Spasojevic Brkic, VK; Putnik, G; Veljkovic, ZA; Shah, V; Castro, H;
Publicação
FME Transactions
Abstract
Students today lack the real experiences needed to make sense of complex technical concepts although industry is one of the primary customers that constantly challenges academia to make curricula more relevant to professional practice. Our response to these influences was to create and test idea of Distributed and Remote Lab dedicated to active learning. In this survey, the experiments on representational fidelity measures are erformed on two types of "client" user interface (Wall and Window) in two modes of presentation (Desktop and Video beam) of the distributed manufacturing system. The proposed remote system has allowed students from Belgrade, Serbia to dynamically interact with a real manufacturing process held in Minho's Lab, Portugal, to carry out a remote experimental practice. This survey gives advantage to Wall interface, in the fields of smooth display of view changes and object motion and consistency of object behaviour. There are also weaker correlations between representational fidelity measures when Wall interface is used and certain advantage on desktop presentation mode. © Faculty of Mechanical Engineering, Belgrade.
2014
Autores
Ferreira, L; Putnik, G; Cruz Cunha, MM; Putnik, Z; Castro, H; Alves, C; Shah, V;
Publicação
Cloud Technology: Concepts, Methodologies, Tools, and Applications
Abstract
The real Cloud and Ubiquitous Manufacturing systems require effectiveness and permanent availability of resources, their capacity and scalability. One of the most important problems for applications management over cloud based platforms, which are expected to support efficient scalability and resources coordination following SaaS implementation model, is their interoperability. Even application dashboards need to easily incorporate those new applications, their interoperability still remains a big problem to override. So, the possibility to expand these dashboards with efficiently integrated communicational cloud based services (cloudlets) represents a relevant added value as well as contributes to solving the interoperability problem. Following the architecture for integration of enriched existing cloud services, as instances of manufacturing resources, this paper: a) proposes a cloud based web platform to support dashboard integrating communicational services, and b) describe an experimentation to sustain the theory that the effective and efficient interoperability, especially in dynamic environments, could be achieved only with human intervention.
2014
Autores
Cardoso, MG; Ferreira, EP; Lopes, MP; Lopes, C;
Publicação
Engineering Optimization IV - Proceedings of the 4th International Conference on Engineering Optimization, ENGOPT 2014
Abstract
In this paper, we present a novel mixed integer linear programming (MIP) model to solve the problem of storage space optimization in a port grain cereal silo. This work is based on a real case study for scheduling storage operations in a port cereal silo, where schedulers are faced daily with the problem of finding the best solution for transfers between storage cells, to maximize the number of empty cells, in order to have greater capacity to receive new lots, subject to storage and transportation lines capacity constraints, and receiving dispatching plans. The problem is formulated by a mixed integer linear programming model and implemented in an Excel/VBA platform. The results show that the model optimizes the number of empty cells, in computational time less than 60 seconds, and thereby constitutes a significant added value to the concerned company. © 2015 Taylor & Francis Group, London.
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