Volumes

Volume LX Number 2/2008

 1.
 Common Fixed Points for (d)-Contractive Multifunctions in Metric Spaces
 Alexandru Petcu 
  pg. 1-4 
 A common fixed point theorem is given in complete metric spaces (X,d) for pairs of multifunctions constrained by a contractive condition only using metric d, without using the Hausdorff metric.
 2.
 Modulation Spaces with Exponentially Increasing Weights
 Mihai Pascu 
  pg. 5-9 
 Modulation spaces were for the first time defined and studied by H. Feichtinger in 1983. Usually the weights used for the definition of modulation spaces have a polynomial growth. But weights with exponential growth can also be used. Such spaces are useful in the study of pseudodifferential operators of infinite order. We shall introduce here a new class of modulation spaces with weights having exponential growth.
 3.
 Linear Interpolation of the Functions with Three Variable Values with Simple Nodes
 Tanase Dinu 
  pg. 10-16 
 The theme of interpolation of a function with three variable values is a complex matter which implies major difficulties when solving it concerning its form , the grade of the polynomial interpolation and the number of points from the definition field .The paper presents two cases of linear interpolation which may be applied when solving problems with elementary fields such as pyramidal.
 4.
 Contre-Continuité dans les Structures Floues Minimaux
 Mihai Brescan 
  pg. 17-26 
 Le but du notre travail est de généraliser pour une structure floue minimale le concept de fonction contrecontinue introduit dans la Topologie générale par Takashi Noiri et Valeriu Popa. Les plus importants résultats sont les théorèmes de caractérisation et les liaisons entres les différentes formes de contrecontinuité et de faible continuité.
 5.
 On a Representation of Mean Residual Life
 Dan Isbasoiu, Ilie Ristea 
  pg. 27-34 
 In this paper, we obtain simple expressions for the mean residual life in terms of the failure rate of certain classes of distributions which subsume many of the standard cases. Several results in the literature can be obtained using our approach.
 6.
 A Comparative Study About the Complexity of Some Recursive Algorithms
 Alexe Calin Muresan 
  pg. 35-42 
 The aim of this paper is to offer a comparative study about the costs involved in fundamental recursive algorithms. We present here the „Fast Fourier Transform”, the „Karatsuba” method and also a method for evaluating the polynomial using the cost of xn and Stirling formula.
 7.
 Interne Approximation for a Variational Inequality Problem
 Lidia Iancu 
  pg. 43-52 
 In this paper we describe a modality to transform a variational inequality in infinite dimension into a problem in finite dimension. We use this theoretical concept for a concrete problem of elasto-plasticity for a simple domain. We use a Math-lab version to programming the calculus of triples integrals witch appear in finite element procedures.
 8.
 Managing Security Monitoring in Enterprise Networks
 Iustin Priescu, Sebastian Nicolaescu 
  pg. 53-58 
 A significant number of high profile cases of malicious software threats and incidents that have dominated media reporting for years have served to raise awareness and determine most businesses to invest time and resources into defending against this prevalent security issue. Security monitoring has gained support being regarded as an essential component for managing and improving the security of network infrastructures. The primary goal of a security monitoring system is to help identify suspicious events on a network that may indicate malicious activity or procedural errors. This paper present the major security monitoring types in current enterprise networked environments.
 9.
 The Novelties of Dreamweaver CS3
 Liviu Dumitrascu 
  pg. 59-64 
 The new version of Dreamweaver CS3[1] is the first edition under the signature Adobe after the ransom of Macromedia in the spring of 2005. It is integrated in the actual range CS3. In this new version CS3, we can use the latest advances of web 2.0: the improved interactivity of the user offered by AJAX Technology [2]. These are the components ready to use, the “widgets spry” of Dreamweaver. In the present paper it is presented the last version of Dreamweaver CS3.
 10.
 Design and Implementation of a Site for the Presentation of a Petrochemical Plant
 Ionut Lambrescu, Doru Stoica 
  pg. 65-70 
 The paper presents the site of a petrochemical plant, created using various technologies. The site is structured in time phases of the plant’s evolution and includes a number of interactive features that allow the visitor to get access to some information about the plant’s units, along with the possibility of seeing in a 3D environment the plant’s units.
 11.
 Comparative Study of Internet Payment Security Protocols Based on Credit Cards
 Ciprian Stanica-Ezeanu 
  pg. 71-76 
 The aim of this paper is to present a comparative study between the three most important Internet payment security protocols based on credit cards: iKP, SET and 3D-Secure. There are presented the advantages and disadvantages between those three payment security protocols for understanding why it was necessary to develop new types of protocols that would answer to as many request from the involved parties as possible.
 12.
 Educational Semantic Networks and their Applications
 Gabriela Moise, Liviu Ionita 
  pg. 77-85 
 In this paper the authors presents an algebraic structure about educational semantic networks. The structure could be used to model the content of an electronical course. This structure enables to perform operations to combine more electronical courses and to obtain a new course, to define a pedagogical technique to teach a course, to pursue the evolution of students during the instruction process. The educational semantic networks could be used in the software development in the field of computer assisted instruction and to design software based on pedagogical agent.
 13.
 An Analysis of Modern Monitoring and Preventing Techniques of Floods
 Alexandra Maria Matei 
  pg. 86-92 
 This paper presents a short analysis of the newest monitoring and preventing techniques applied to the management of emergency situations from a river basin. The analysis relates to some up-to-date software systems implemented in national and international projects about monitoring and preventing of floods. Usage of artificial intelligence in monitoring and preventing of floods proves better results than conventional methods. In order to improve the efficiency of these techniques, it is proposed to apply artificial intelligence techniques such as experts systems, data mining, intelligence agents.
 14.
 e-Voting Security
 Ciprian Stanică-Ezeanu 
  pg. 93-98 
 The aim of this paper is to present e-voting procedure describing its advantages and disadvantages. Conventional security measures such as firewalls or SSL communications are necessary but not sufficient to guarantee the specific security requirements of e-voting. Besides these conventional security measures, it is also necessary to implement an additional layer of specialized security technology to address the specific risks posed by electronic voting and guarantee critical security requirements such as voters’ privacy, vote integrity and voter-verifiability.
 15.
 Pressure-assisted Crystallization of Cu-Zr-Ti Glass-forming Alloys
 Manuela Stir, Anca Baciu, Radu Nicula 
  pg. 99-103 
 Alloy powders with nominal composition Cu60Ti20Zr20 were investigated by in-situ X-ray diffraction at the B2 powder diffraction beamline (HASYLAB/DESY, Hamburg, Germany) and by X-ray diffraction experiments during continous heating under uniaxial pressure at the F2.1/MAX80 beamline in HASYLAB. The structural phase transitions in the nanocrystalline Cu60Zr20Ti20 were investigated for continuous heating at three different pressures, namely 0.6GPa, 1.0GPa and 1.7GPa. The pressure dependence of the phase transition temperatures was obtained.
 16.
 On Fractional Wavelet Transform
 V.I.R. Niculescu, Liana Sandru 
  pg. 104-108 
 The wavelet theory is a powerful method for processing different physical and chemical signals. The fractional wavelet can be obtained from the a fractional window. In this brief report we present a new wavelet transform which is obtained from Agnesi window. This class of wavelet transform is a flexible one because dependents on two parameters (dilatation or contraction, position). It cover also combinations of discrete and continuous parameter discretisations (hybrid cases).
 17.
 Mechanical and Tribological Characteristics of Hard Multilayer Coatings Deposited by Arc Cathodic Technique
 V. Braic, M. Braic, M. Balaceanu, A. Popescu, R.G. Ripeanu, I. Tudor 
  pg. 109-114 
 Mechanical and tribological properties of the alternate TiN/TiAlN, ZrN/TiAlN, TiSiN/Ti and TiSiN/Cu multilayer coatings prepared by the cathodic arc technique were investigated. The microhardness, thickness, adhesion, friction coefficient and wear resistance measurements were carried out. The properties of these multilayer’s were compared with those of TiAlN,ZrN and TiSiN monolayer’s.
 18.
 The Problem of Relation between Energy and Mass
 Ion Simaciu, Zoltan Borsos, Mihai Hotinceanu 
  pg. 115-121 
 In this paper, we analyze the concepts about two fundamental physical measures: the energy and the mass. In first part, we presented these concepts from the classical physics. In part two, are presented the concepts from the modern physics: the relativistic physics and the quantum physics. In part three, are presented new arguments to support the fact that the measures are qualitative distinct and the Einstein relation is just a quantitative relation between mass in the proper referential system and energy. The key of the problem solution is a relativistic definition of the speed in connections with the relativistic definitions the path length and the duration of the path. The relativistic definitions are compatible only in the case of proper speed υ = dr / dτ. In this case, the relativistic momentum is the product between the mass in proper reference and proper velocity p = m υτ = m υ / sqrt( 1- υ2/c2).
 19.
 Current SUSE Pearl Undulator
 Liana Sandru, V.I.R. Niculescu, S. Miclos, Minola R. Leonovici 
  pg. 122-126 
 A new undulator structure for free electron lasers was presented. Current SUSE Pearl devices produce magnetic fields which are spatially periodic. The current structure was in the shape of wire stacks. The current has alternating directions. The magnetic field components for each wire presents symmetry with two axis. The undulator transverse cross-section SUSE Pearl was represented by two SUSE Pearls in mirror. The Biot - Savart law was numerically evaluated. The magnetic field was mainly longitudinal and easily adjusted with the current. The versatility of values cover longitudinal undulator or wiggler design for two beams devices with transverse momenta.
 20.
 Example for Determination of the Phase Inversion Point
 Anca Baciu, Nicolae Mosescu, Georgeta Nan 
  pg. 127-130 
 The phase inversion refers to a phenomenon where with a small change in the operational conditions, the continuous and dispersed phase spontaneously inverts. For instance, in oil-water systems, dispersion (emulsion) of oil drops in water becomes dispersion (emulsion) of water drops in oil, or vice versa. The phase-inversion is a major factor to be considered in the design of oil-water pipelines, since the rheological characteristics of the dispersion and the associated pressure drop change abruptly and significantly at or near the phase inversion.
 21.
 Microcellular Carbon from Polymer Materials Pyrolysis
 Georgeta Nan, Ioan Stamatin, Adriana Andronie, Stefan Iordache, Nicolae Mosescu, Serban Stamatin, Marilena Ceaus 
  pg. 131-136 
 The microcellular carbon is an advanced material due to its properties related to chemical inertness and thermal conductivity where high rate of heat exchange is required. In addition the carbon resulted from polymer pyrolysis exhibit various properties of gas adsorption and separation. Microcellular carbon is usual obtaining by foaming of the pyrolized polymers with different agents. The results lead to uncontrolled pore sizes. This contribution deals with a new method of the polymer pyrolysis consisting of thermal treatment of the composite materials polymer-nondecomposable salts. At 700 0 C structures of microcellular carbon have been developed from polyacrylonitrile polymer matrices with addition of salt. The structure and the properties of polymer materials were investigated by, Raman and SEM.
 22.
 Teachers’ Views of Science, Physics and Technology
 Mariana Bradac 
  pg. 137-140 
 Recent research in science education shows that teachers have ideas, attitudes, and behaviors related to science teaching based on a lengthy "environmental" training period, in which they themselves were students. The influence of this incidental training is enormous because it corresponds to reiterated experiences acquired in a non-reflexive manner as something natural, thus escaping criticism. We will discuss how the view of science contained in the curriculum affects teaching, although this is clearly of major significance. This is essential to give a correct image of Science / Technology / Society interactions.