All issues
Creative Mathematics
and Informatics

Print Edition: ISSN 1584 - 286X
Online Edition: ISSN 1843 - 441X

Creative Math. and Inf. is a category B+ journal in the CNCSIS classification

Indexed by:
Mathematical Reviews
Zentralblatt MATH

Current rejection rate: 37.5 %


Vol. 16 (2007),
Some interpolation schemes with triangular and rectangular nodes of Birkhoff type
Author: Marius M. Birou
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No. of downloads: 488 Full access PDF | DVI | PS |
Modified Jakimovski-Leviatan operators
Author: Alexandra Ciupa
Abstract: In this paperwe modify the Jakimovski-Leviatan operators, in order to improve the rate of convergence. We estimate the order of approximation and we give a Voronovskaya type theorem.
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No. of downloads: 454 Full access PDF | DVI | PS |
Some primality and factoring tests
Author: Cristina Flaut
Abstract: In this paper we try to give some properties of strong pseudo-prime numbers and their applications in cryptography and algebra, more precisely in the factorization in Z[i].
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No. of downloads: 436 Full access PDF | DVI | PS |
About the orthogonal relations in the statistical estimation
Author: Ion Mihoc / Cristina Ioana Fătu
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No. of downloads: 422 Full access PDF | DVI | PS |
Differentiability with respect to delays for a Lotka-Volterra system
Author: Diana Otrocol
Abstract: We study the differentiability with respect to delays using the weakly Picard operators technique.
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No. of downloads: 433 Full access PDF | DVI | PS |
Solving the generalized minimum spanning tree problem with simulated annealing
Author: Petrică C. Pop / Cosmin Sabo / Corina Pop Sitar / Marian V. Crăciun
Abstract: We consider a generalization of the minimum spanning tree problem, called the generalized minimum spanning tree problem, denoted by GMST. It is known that the GMST problem is NP-hard. We present an effective algorithm for this problem. The method combines a simulated annealing algorithm (SA) with a local greedy algorithm. The heuristic that we proposed found solutions that were optimal for graphs with nodes up to 280 and were within at most 24% of optimality for larger problems, while the existing algorithms from the literature become computationally intractable.
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No. of downloads: 469 Full access PDF | DVI | PS |
The generalization of Voronovskaja’s theorem for exponential operators
Author: Ovidiu T. Pop
Abstract: In this paper we will demonstrate a Voronovskaja’s type general theorem for exponen- tial operators. By particularization, we obtain Voronovskaja’s type theorems for the different operators.
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No. of downloads: 449 Full access PDF | DVI | PS |
Artin symbol of the Kummer fields
Author: Diana Savin
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No. of downloads: 402 Full access PDF | DVI | PS |
A direct finding of the supremum of sequences explained by a fixed point theorem and some new results in asymptotic analysis
Author: Andrei Vernescu
Abstract: We present an explanation by a fixed point theorem of a situation in the theory of the sequences. Some additional facts are given.
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No. of downloads: 410 Full access PDF | DVI | PS |
Implementing some mathematical models to be applied in the cost calculation systems
Author: Diana Andrada Filip / Gheorghe Fătăcean / Rodica Ioana Lung
Abstract: An improvement of the classical model for determining the cost of goods, in condition in which we assist a new governance in the economic entity, based on the cost allocation of resources consumption connected to the activity efficiency is proposed. This model applies a series of coefficients in allocation process of the indirect expenses over the cost at different level of activity and responsibility like: production, administration and sales.
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No. of downloads: 413 Full access PDF | DVI | PS |
The study of some nonlinear dynamical systems modelled by a more general Rayleigh-Van Der Pol equation
Author: Mircea Lupu / Florin Isaia
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No. of downloads: 444 Full access PDF | DVI | PS |
A Markov model in cervical cancer screening strategy
Author: Luciana Neamţiu
Abstract: Cancer is an important public health problem. The cost of cancer therapy is very high. Meanwhile, the prevention of some types of cancer is effective. Generally, Markov models are used to modelling chronic disease for health care (see [1], [2], [5]). This paper introduces a Markov model for cervical cancer screening programme.
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No. of downloads: 430 Full access PDF | DVI | PS |
Some refinements of relative information inequality
Author: J. Rooin / A. Morassaei
Abstract: In this article, using some refinements of Jensen’s discrete inequality, we give some new refinements of Kullback-Leibler’s relative information inequality
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No. of downloads: 430 Full access PDF | DVI | PS |
Computing constrained default extensions - a constraint satisfaction problem
Author: Gabriela Șerban / Mihaiela Lupea
Abstract: Constrained default logic belongs to the class of default logics which formalize default reasoning. This type of nonmonotonic reasoning is modelled by defaults which permit inferring conclusions in the absence of complete information, using default assumptions. Using the classical inference rules and the defaults, the set of initial facts is extended with formulas, called nonmonotonic theorems (beliefs), obtaining extensions. This paper presents a new approach in computing constrained extensions. We define the problem of computing the generating default sets of extensions as a constraint satisfaction problem and we introduce BTCE algorithm for solving this problem. The proposed algorithm is based on a top-down approach and uses pruning for an efficient search.
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No. of downloads: 413 Full access PDF | DVI | PS |
Minimal surfaces
Author: Jana Veckova
Abstract: Tensioned membrane constructions have many good physical qualities besides that they are architectonical very interesting. Their construction can start from minimal surfaces. Computation of inner points of surface with minimal area from prescribed boarder is quite difficult in many respects. I was inspired by Spanish research by JuanMonterde who focused on Plateau-B´ezier problem in 2002, [1]. Minimal surfaces are constructed approximately during construction in engineering. Therefore we are looking for means that can approximate the searched surface with respect to the best accession to minimal surface area. One possibility to solve such problem is to investigate surfaces that are parameterized by polynomial functions, in particular by B´ezier surfaces, or by piecewise polynomial functions.
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No. of downloads: 399 Full access PDF | DVI | PS |
Unimodal multicriteria optimization via Fibonacci numbers
Author: Ioana Ghiorean / Liana Lupşa / Nicolae Popovici
Abstract: The aim of this work is to develop a numerical method for approximating the efficient sets in multiple criteria optimization problems involving unimodal objective functions. A parallel algorithm corresponding to this method is presented, too.
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No. of downloads: 395 Full access PDF | DVI | PS |
Comparative study on some parameters of a text independent speaker identification system for Romanian language based on GMMwith MFCC vectors
Author: Marieta Gâta / Gavril Toderean
Abstract: The speaker recognition technique used here is based on GMM. This approach consists in three phases: parameterization, model training and classification. We compare a model of a speech extracted from an unknown speaker with the models of speakers contained in our database. Models are calculated with EM (Expectation Maximization) algorithm for GMM (Gaussian Mixture Models). We study the influences of several parameters: different texts in the training process and in the testing process, numbers of Gaussians, number of speakers, amount of training data (length of the wav file in seconds), numbers of iterations.
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No. of downloads: 346 Full access PDF | DVI | PS |
On monotonic and translation-invariant multiresolution analysis constructions
Author: Radu Lucian Lupșa
Abstract: As a continuation of a previous work on generalizing the multiresolution analysis from the wavelets and applying it in a lattices context, this paper studies multiresolution analysis on subsets of R^n. Of primary interest are multiresolution analysis by monotonic and translation-invariant functions; the paper studies their characterisation, properties, and possible constructions.
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No. of downloads: 405 Full access PDF | DVI | PS |
Comparison of 3 implementations of the A* algorithm
Author: Livia Sângeorzan / Kinga Kiss-Iakab / Maricica Sîrbu
Abstract: This paper deals with a short presentation of the A* algorithm and the comparison of three different implementations of the algorithm. A* is a graph search algorithm that finds a path from a given initial node to a given goal node (or one passing a given goal test). It employs a ”heuristic estimate” that ranks each node by an estimate of the best route that goes through that node. It visits the nodes in order of this heuristic estimate. The A* algorithm is therefore an example of best-first search, which optimizes the depth-first search. What sets A* apart from best-first search is that it also takes the distance already travelled into account. This makes A* complete and optimal, i.e., A* will always find the shortest route if any exists. It is not guaranteed to perform better than simpler search algorithms. In a maze-like environment, the only way to reach the goal might be to first travel one way (away fromthe goal) and eventually turn around. In this case trying nodes closer to your destination first may cost you time. In addition to finding a path for a unit to move along, pathfinding can be used for several other purposes: exploration, spying, road building, terrain analysis, city building, puzzle solving. So the main application domain is game design.
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No. of downloads: 408 Full access PDF | DVI | PS |
Metrics for component-based system development
Author: Camelia Şerban / Andreea Veşcan
Abstract: Component-based development (CBD) advocates the acquisition, adaptation, and integration of reusable software components to rapidly develop and deploy complex software systems with minimum engineering effort and resource cost. The work of integrating the components with each other and with the rest of the system is the most important part of the component-based development process. The interaction among components in an assembly is essential to the overall quality of the system. When integrating components into a system assembly, it would be useful to predict how the quality attributes for the whole system will be. In order to predict and to asses quality attributes, the usage of software metrics is a necessity. Useful insight on the specificities to consider when developing metrics for CBD are presented, both concerning individual components (assessing components in isolation) and component assemblies (assembly-centric evaluation approach) are presented. Concerning the component-assembly approach we adapt metrics for object-oriented design (CBC - Coupling Between Components) and new metrics are defined (DDT - Depth Dependence Tree and BDT - Breadth Dependence Tree).
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No. of downloads: 386 Full access PDF | DVI | PS |
An agent based user interface evaluation using aspect oriented programming
Author: Adriana M. Tarța / Grigoreta S. Moldovan / Gabriela Șerban
Abstract: Human-computer interaction design has an essential role in the success or failure of a software product. The user interface reflects this aspect of the system. In this paper we propose a new alternative for evaluating user interfaces using an agent-based approach. The Intelligent Agents domain is an important research and development area in the field of Computer Science and of Artificial Intelligence, particularly [16]. It provides a new mechanism for problem solving and a new user-computer interaction method. In our proposal, based on task models (task trees), agents are used for monitoring and assisting users in interaction with the system. Task models [17] are used in the user centered design context in order to give valuable information about the sequence of actions the user must perform to accomplish his/her goals. In order to separate the agent from the evaluated software system, we use a recently developed programming paradigm, Aspect Oriented Programming [6].
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No. of downloads: 380 Full access PDF | DVI | PS |
Overview and architecture of a component modeling tool
Author: Andreea Veșcan / Simona Motogna
Abstract: Component-based development (CBD) advocates the acquisition, adaptation, and integration of reusable software components to rapidly develop and deploy complex software systems with minimum engineering effort and resource cost. The paper first presents previous results regarding component-based development and describes the used architecture. Further, the paper provides the steps (scenarios) when using a tool for developing a componentbased system by assembling components: finding and selecting components or create new components; adapting components; syntactic system assembling, providing data and control flow; analyzing composition behavior, and deploying the system. The previous work done by the authors is also described and an analysis about how to integrate them into the tool development is done.
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No. of downloads: 385 Full access PDF | DVI | PS |

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