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Constanţa, Romania

Lascu D.,Mircea Cel Batran Naval Academy
The Scientific World Journal | Year: 2014

We consider a family {τ m: m ≥ 2} of interval maps which are generalizations of the Gauss transformation. For the continued fraction expansion arising from τ m, we solve a Gauss-Kuzmin-type problem. © 2014 Dan Lascu.

Bautu E.,Ovidius University | Bautu A.,Mircea Cel Batran Naval Academy | Luchian H.,Al. I. Cuza University
CISIS 2010 - The 4th International Conference on Complex, Intelligent and Software Intensive Systems | Year: 2010

Forecasting applications on the stock market attract much interest from researchers in the artificial intelligence field. The problem tackled in this study concerns predicting the direction of change of stock price indices, formulated in terms of binary classification. We use gene expression programming to evolve pools of binary classifiers and investigate several approaches to construct ensembles based on them. We compare the performance of the obtained classifiers with those of Naive Bayes, Support Vector Machines, Multilayer Perceptron, Decision Table and Random Forrest. The experiments performed on real-world stock market data show that the ensembles of GEP-evolved classifier models are competitive to classifiers trained by state-of-the-art machine learning methods. © 2010 IEEE.

Marin G.,Research Center for Navy | Samoilescu G.,Mircea Cel Batran Naval Academy | Baltag O.,Victor Babes University of Medicine and Pharmacy Timisoara | Radu S.,Barklav Shipping Agency
EPE 2014 - Proceedings of the 2014 International Conference and Exposition on Electrical and Power Engineering | Year: 2014

The issue of electromagnetic compatibility and bioelectromagnetic compatibility is critical onboard ships, especially on naval ships, characterized by a large number of antennas transmitting in various frequency range, and placed in a small area. The paper presents some measurements performed on a Romania naval ship, in order to determine whether the personnel onboard is exposed to dangerous electromagnetic radiations. There were considered several high traffic areas on the ship, and measurements were performed in two frequency ranges: 80-200 MHz and 200-2500 MHz, respectively. The results represent measurements of the far-field of antennas. Compared to the electric field strength limits for controlled environments imposed by European regulations, the measured values were definitely lower. © 2014 IEEE.

Zaidi S.,Constantza Maritime University | Ristea M.,Mircea Cel Batran Naval Academy | Bocanete P.,Constantza Maritime University
International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM | Year: 2014

The naval industry is oriented towards a greener operation for the ships; this goal can be achieved by implementing green technology onboard vessels, even if we are not dealing with new constructions, but rather with ships that are the subject of retrofitting. By implementing during the retrofitting period technologies that aims Renewable Energy Sources, the overall efficiency of the propulsion system will be surely increased. In this paper there are carried out transient RANS – VOF simulations for the flow around a KVLCC2 tanker model which has attached a towing kite to its bow, in order to determine the additional power that becomes available when using the high altitude towing kite which is designed to decrease considerably to operating costs of a ship, by lowering the consumption rates by 10% to 35% average winds. This concept was developed to act as a supplementary power source in addition to ship’s main engine. The simulation is carried by using Ansys CFX simulation package. Attention will be given to the discretization of the convective term and the modelling of turbulence. © 2014, SGEM. All Rights Reserved.

Cristea O.,Mircea Cel Batran Naval Academy | Popescu M.-O.,Polytechnic University of Bucharest | Calinciuc A.S.,ANCOM
2014 International Symposium on Fundamentals of Electrical Engineering, ISFEE 2014 | Year: 2015

In the middle of a continuous and exponential development of renewable energies trend, generated by the increasing price of the conventional fuels which are quickly draining, and facing the fact that we have tremendous messages sent by our polluted Planet, the IMO (International Maritime Organization) returned its face to environment concerns in 2008. During time IMO has realized a series of environment impact studies of maritime domain and, in concordance with this idea, developed IMO's Marine Environment Protection Committee (MEPC). MEPC has given extensive consideration to control of greenhouse gas (GHG) emissions from ships which are implemented in MARPOL Annex VI as a new Chapter 4, entitled 'Regulations on energy efficiency for ships'. We strongly believe that there will be a rapid grow in the number of ships which will have renewable energies systems onboard in the near future. One kind of energy that can be very well applied to the naval domain is the solar energy. As the technologies are developing very fast in the domain of photovoltaics, there is a continuous need of research in order to implement the best technical solutions in naval domain, which, as we know, presents different characteristics from classic terrain applications. Thus, there are some questions that we tried to respond on this article, as: 'what is the difference between efficiency of an onboard installed PV panel and a classic terrain installed PV panel?; how much will affect the albedo of the water?; how much will affect the ships' oscillation moves?; how is comporting a vertical Sun facing PV panel and a non-facing one? To respond at these questions we realized a comparative study between a simulated PV system and its similar real system installed onboard, in order to determine the differences between results and estimate how much we can take in consideration from a simulated PV classic system when we design a real onboard PV system. © 2014 IEEE.

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