ÿþ<html> <head> <link href="http://fmi.spiruharet.ro/annals/css/css.css" rel="stylesheet" type="text/css"> <title>Annals of Spiru Haret University, Mathematics-Informatics Series</title> <script language="jscript" type="text/javascript"> function cfmover(Obj){ Obj.style.backgroundColor='#3366aa'; Obj.style.color='white'; } function cfmout(Obj){ Obj.style.color='#3366aa'; Obj.style.backgroundColor='#ffffee'; } </script> </head> <body ><!-- '#3366aa' --> <table style="width:100%; "> <tr> <td style="width:10%"> </td> <td style="border-bottom:solid 1px black; border-right:solid 1px black; border-left:solid 1px #aaaaaa; border-top:solid 1px #aaaaaa;"> <table class="alb" style="width:100%;"> <tr> <td align=center bgcolor="#3366aa" valign="middle" style="border-bottom:solid 1px black; border-right:solid 1px black; border-left:solid 1px #aaaaaa; border-top:solid 1px #aaaaaa;"> <!-- #C68D46 --> <span class="sitetitle"><br>Annals of Spiru Haret University, Mathematics-Informatics Series<br>&nbsp;</span> </td> </tr> <tr> <td> <table style="width:100%;"> <tr> <td width="90%" style="padding:20px; text-align:justify; color:#666666; font-family:verdana; font-size:10pt;"> <table class="tzero"><tr> <td width="109"><img src="http://fmi.spiruharet.ro/bodorin/ximg/siglaush.jpg" width="109" ></td> <td style="padding:20px;"> <span class="captitle">Analele Universitcii Spiru Haret, <br>Seria Matematic-Informatic, <br>ISSN: 1841-7833 <br>CNCSIS B+ (CNCSIS code: 985) </span> </td> </tr></table> <a><div class="sepemptyw"></div></a> <span class="captitle">Analele Universitcii <i>Spiru Haret</i>, Seria Matematic-Informatic, VI(special issue), 2010, Abstracts and Keywords</span> <hr size="1"> <A name="2010-s0"><b>0.</b></a> ALBEANU, Grigore; VLADA, Marin, <i>NEW RESULTS ON E-LEARNING METHODOLOGIES</i><br> <b>Abstract</b>: This note introduces invited papers on recent results on e-Learning methodologies. Some articles are extensions of previously published papers in the proceedings of the International Conference on Virtual Learning, other contributions being quite new. <br> <b>Keywords</b>: <i>ICVL, e-Learning, computer-based education, e-pedagogy </i> <br> <hr size="1"> <A name="2010-s1"><b>1.</b></a> CHEN, Zhengxin, <i>RETHINKING THINKING: USING ONTOLOGIES FOR E-TECHNOLOGY ENABLED INTEGRATED PROBLEM SOLVING</i><br> <b>Abstract</b>: Real-world problem solving requires integrated problem solving skills. However, in reality, various problem solving techniques have been covered in separate courses in computer science (or other Information Technology-related) curriculum, leaving little time for students to apply learned knowledge together. The advent of E-technology provides an excellent opportunity to change this. In particular, in this paper we take a look at the issue of using ontologies to enable integrated problem solving. We start with a general review on ontologies, pointing out the dual role of ontologies as an e-technology in education. We then focus on the role of ontologies for integrated problem solving by reviewing our recent experiences from a number of student projects in database management system (DBMS), artificial intelligence (AI), data mining (DM) and other senior level courses, pointing out the important role of ontology as a common theme to thread various aspects related to intelligent information systems. These projects have shown exploring ontology-related aspects is an effective way for students to develop skills in integrated problem solving.<br> <b>Keywords</b>: <i>intelligent problem solving, ontologies, E-technology in education </i> <br> <hr size="1"> <A name="2010-s2"><b>2.</b></a> ALLEGRA, Mario; LA GUARDIA, Dario; GENTILE, Manuel; TAIBI, Davide; FULANTELLI, Giovanni, <i>A DIGITAL GAME APPROACH FOR ENTREPRENEURIAL MINDSETS</i><br> <b>Abstract</b>: The OSLO conference and agenda on "Entrepreneurship Education in Europe: Fostering Entrepreneurial Mindsets through Education and Learning", highlight the main experiences in Europe and their outcomes regarding the promotion of entrepreneurship in education. Education and training should contribute to encouraging entrepreneurship by fostering the right mindset, providing relevant skills for self-employment, raising awareness of career opportunities as an entrepreneur. Entrepreneurship learning has taken place almost everywhere at secondary school in Europe, but there are no shared entrepreneurship oriented models for different educational levels and systems. Entrepreneurship is defined (European Commission 2002) as "a dynamic and social process where individuals, alone or in collaboration, identify opportunities for innovation and act upon these by transforming ideas into practical and targeted activities, whether in a social cultural or economic context"; therefore, entrepreneurship in education includes economic, social and cultural factors. For this reason it is important to identify educational models to support students in the development both of personal qualities and attitudes and of formal knowledge and skills, and in particular:<br> - Personal qualities and attitudes increase the probability of a person recognizing opportunities and acting on them. <br> - Knowledge and skills concern what must be done to establish a new enterprise, and how to be successful in developing an idea into a practical, goal-oriented enterprise?<br> <p>Our research focuses on the study of ICT solutions concerning on line entrepreneurial environments based on social networking.</p> <p>Entrepreneurial networking is more than just collaboration since it stimulates the ability to find and create new relationships, the ability and the know how to identify the key competencies that can be useful in developing entrepreneurial mindsets. </p> <b>Keywords</b>: <i>Digital Games, MMORPG, MMOLE, Virtual Worlds, E-mindsets</i> <br> <hr size="1"> <A name="2010-s3"><b>3.</b></a> DINEVA, Snejana, <i>A STUDY ON STUDENTS' VIEWS ON BLENDED LEARNING ENVIRONMENT USAGE</i><br> <b>Abstract</b>: The purpose of the article is to represent the opinion of our students that have been enrolled in web-based course on Ecology during their traditional face-to-face education. The analyses of the data had reflected students learning and satisfaction especially on the usage of the online materials and workshop components of blended mode of learning. The results show that students prefer integrated combination of face-to-face traditional with web based online teaching and learning activities. <br> <b>Keywords</b>: <i>e-learning, blended learning, self-preparation, online education, Web-supported e-learning</i> <br> <hr size="1"> <A name="2010-s4"><b>4.</b></a> RAILEAN, Elena, <i>METASYSTEMS APPROACH TO RESEARCH THE GLOBALISATED PEDAGOGICAL PROCESSES</i><br> <b>Abstract</b>: The chapter investigates metasystems approach to research the globalisated learning processes, demonstrating new controversies in the learning theory caused by phenomena of the globalisation. The proposed solution reside in GAE paradigm and new didactical model, which seeing learners as knowledge workers acting in physical - virtual learning environment. The core element of the model is competence three-dimensional structure. The functionality of the structure is assured by the flexible and dynamic instructional strategy. The aim of the strategy is to develop self-regulated competence through electronic textbook (ET). The strategy provides an operating framework for new learners. <p>The purpose of the chapter is to elucidate significance of new didactical model and powerful learning environments. The contents are framed under three categories: the theoretical approach; didactical model and experimental data validation. Conclusions and future research directions are provided at the end.</p> <b>Keywords</b>: <i>Functional competence, open educational system, electronic textbooks, learning environment and self-regulated learning competence</i> <br> <hr size="1"> <A name="2010-s5"><b>5.</b></a> GENTILE, Manuel; FULANTELLI, Giovanni; TAIBI, Davide; ALLEGRA, Mario, <i>TOWARDS THE LEARNING OBJECT MANAGEMENT SYSTEM AND DYNAMIC USE OF METADATA</i><br> <b>Abstract</b>: In this paper we illustrate a dynamic approach in the use of the metadata and how this concept can dramatically improve the management of Learning Objects. Specifically, the ideas elaborated in this paper rise from the experiences in managing Learning Object Repositories during three European funded projects: Sloop, Tenegen, and Sloop2desc. <br> <b>Keywords</b>: <i>Open Educational Resources, Open Learning Objects, Communities of practice, Learning Object Management Systems, Web 2.0</i> <br> <hr size="1"> <A name="2010-s6"><b>6.</b></a> KITAGAKI, Ikuo, <i>E-LEARNING FOR ENGLISH LANGUAGE SPEAKING SKILL</i><br> <b>Abstract</b>: We here discuss an e-learning for English speaking skill. The learning system aims at improving the speaking skill through memorization of short sentences. The method of the system is as follows: <br> 1. A short sentence in the learner's mother tongue is either displayed on a computer monitor, or is communicated by audio. <br> 2. The learner translates the sentence quickly. <br> 3. The system displays the correct answer. <br> 4. The system then selects and displays another short sentence from the collection.<br> <p> The steps shown above are repeated. All what the learner has to do is total memorization of all translations.</p> <p>We evaluated the learning effectiveness of the method with the e-learning by asking few participants to use the system. For the evaluation, we created short sentences and equally divided them into Set A and Set B. Set A contained sentences that are be learned, and Set B contained sentences that are not to be learned. The participants were subjected to pre-test and post-tests containing sentences from both sets. The participants' vocal answers for both pre and post tests were evaluated in terms of fluency. The evaluation revealed that not only did the participants improve their speaking skills for the sentences in Set A (direct effect), they showed improvements toward sentences in Set B (indirect effect). More specifically, indirect effects were observed for 7 out of 9 sentences as a statistical significance.</p> <b>Keywords</b>: <i>E-learning, Language education, Evaluation, Speaking skill</i> <br> <hr size="1"> <A name="2010-s7"><b>7.</b></a> RAILEAN, Elena, <i>THE E-LEARNING STRUCTURE - CONTEXT METHODOLOGY</i><br> <b>Abstract</b>: This article investigates the concept of structure - context methodology (SCM) used to elicit the process of forming the key competence. The work discusses SCM as the base component of electronic textbooks development. The study is supported by practical applications, whose characterizations allow us to understand the role of structure-context methodology for new e-Learning technology. A brief theoretical and conceptual approach is presented and major contribution and difficulties are discussed. New questions and future trends about the functional contexts methodology are suggested. <br> <b>Keywords</b>: <i>theory of learning, electronic textbooks, structure - context methodology</i> <br> <hr size="1"> <A name="2010-s8"><b>8.</b></a> TAIBI, Davide; GENTILE, Manuel; FULANTELLI, Giovanni; ALLEGRA, Mario, <i>COLLABORATIVE CREATION OF OPEN EDUCATIONAL RESOURCES: TEACHERS IN THE NET GENERATION </i><br> <b>Abstract</b>: This paper describes the approach followed by three European Founded projects in order to reduce the gap between teachers and Net Generation students. The students use the Web 2.0 environments to share, comment and tag different types of media collaboratively using social network sites. The evolution of the Sloop project results in the following Tenegen and Sloop2desc projects leads teachers to produce, share, comment, tag and modify Open Learning Resources, as their students are used to do on the Web 2.0. In fact, one of the most interesting challenges faced in the three projects was how to train teachers from traditional schools on the use of new tools and environments that support collaboration and sharing in a Web 2.0 perspective. The projects promote the use of social network activities with the aim of encouraging the collaborative production of learning objects thus developing collective intelligence. <br> <b>Keywords</b>: <i>Open Learning Objects, Open Educational Resource, Net Generation, Web 2.0</i> <br> <hr size="1"> <A name="2010-s9"><b>9.</b></a> STANESCU, Ioana; STEFAN, Antoniu; HAMZA-LUP, G. Felix; STEFAN, Veronica, <i>SIMULATION AND HAPTIC-ENABLED FRAMEWORKS FOR VIRTUAL LEARNING ENVIRONMENTS</i><br> <b>Abstract</b>: The ability to interact with synthetic entities as if they were real has been the ultimate quest of virtual reality (VR) researchers for decades. Recent advances in virtual environments allow users to see virtual objects and avatars, to hear them, to move them, and to touch them. The direct physical interaction with computer-generated objects enabled by haptic interfaces provides a useful and intuitive augmentation to visual display and the opportunity to enhance the level of understanding of, and interactivity with, complex data sets. These emergent technologies require a new generation of learners, very different in terms of skills and attitudes, demanding the implementation of radical changes. This paper considers the enhancement of a web-based knowledge-driven decision support system designed for implementation in clinical learning settings. The authors explore the use of virtual reality training solutions in practice-based learning and skill rehearsal in medical and clinical situations to create life like simulations. <br> <b>Keywords</b>: <i>knowledge management, multimodal interface, haptic technology</i> <br> <hr size="1"> <A name="2010-s10"><b>10.</b></a> AWAD, Abdelkarim; GHANEM, Wasel, <i>COMPUTER ORGANIZATION: HARDWARE DESCRIPTION LANGUAGE APPROACH </i><br> <b>Abstract</b>: Teaching of computer organization and architecture concepts is not an easy task for instructors. Usually, Students face difficulties in grasping many (even simple) ideas. In this paper we will present a stereotype of using Computer Aided Design CAD tools, namely, Altera's Quartus II simulator, in teaching Computer Organization concepts. We will build a simple computer using verilog HDL language. We will elaborate on the Instruction Set Architecture (ISA) concepts. In our approach we will provide students with a running simple computer, which will make the simulation possible and easy. This way, they can trace the execution of the simple computer that has few instructions stored in the memory. After that students can route the program on a FPGA which is important because it will teach them how to build their own processor. At the end, students can expand the computer in several dimensions (e.g. more instructions, more addressing modes, cache, speculative execution, little or big Endian, ...). We present at the end of this paper a typical exercise that can help students to improve their knowledge about the computer organization. As a future work we introduced Moodle as a good candidate to be used in the e-learning process.<br> <b>Keywords</b>: <i>Simple computer, Instruction Set Architecture (ISA), Verilog HDL </i> <br> <a><div class="sepemptyw"></div></a> <span class="captitle">Analele Universitcii <i>Spiru Haret</i>, Seria Matematic-Informatic, VI(Issue 1), 2010, Abstracts and Keywords</span> <hr size="1"> <A name="2010-a1"><b>1.</b></a> GHICA, Manuela, <i>APPROXIMATE SADDLE POINTS PORTFOLIOS</i><br> <b>Abstract</b>: We introduce the concept of <i>saddle points portfolio</i> and we establish a connection between this concept and the <i>approximate minima</i>. <br> <b>Keywords</b>: <i>reinsurance market, portfolio, saddle points, Lagrangian function</i> <br> <hr size="1"> <A name="2010-a2"><b>2.</b></a> DUMITRU, Dan, <i>CONNECTEDNESS OF THE ATTRACTORS OF ITERATED FUNCTION SYSTEMS</i><br> <b>Abstract</b>: We survey some of the topological properties of the attractors of iterated function systems such as connectedness, arcwise connectedness and locally arcwise connectedness. We give necessary and sufficient conditions for the attractors of finite iterated function system (IFS) to be a connected sets and in the case when infinite iterated function systems (IIFS) are considered we give only some sufficient conditions. Attractors with many connected components are also considered in the case of IFSs. We also describe the shift space associated to an attractor. Some examples are given for each considered case. <br> <b>Keywords</b>: <i>attractors, iterated function systems, connectednes, arcwise connectedness</i> <br> <hr size="1"> <A name="2010-a3"><b>3.</b></a> VÂRGOLICI, Horia, <i>ON THE EXPONENTIAL DIOPHANTINE EQUATION</i><br> <b>Abstract</b>: The aim of this paper is to give all nonnegative solutions <i>(x, y, z)</i> to the equation <i>2<sup>x</sup> + p <sup>y</sup>=1009 <sup>z</sup></i>, where <i>p</i> is a positive rational prime number with <i>3 &le; p &le; 997</i> (167 equations) <br> <b>Keywords</b>: <i>exponential Diophantine equation, Lebesgue-Nagell equation, Catalan equation</i> <br> <hr size="1"> <A name="2010-a4"><b>4.</b></a> VORNICESCU, Neculae, <i>APPROXIMATION OF FUNCTIONS OF TWO VARIABLES BY DISCRETE LINEAR POSITIVE OPERATORS</i><br> <b>Abstract</b>: We introduce a class of discrete linear positive operators in the space of real continuous functions of two variables defined on the square <i>[0,1] x [0,1]</i>. These operators are associated to an arbitrary set of nodes <i>(x<sub>i</sub>,y<sub>j</sub>), i=0, ..., m, j=0, ..., n</i>, and preserve the linear functions. <br> <b>Keywords</b>: <i>linear positive operators, polynomials</i> <br> <hr size="1"> <A name="2010-a5"><b>5.</b></a> ALBEANU, Grigore; MADSEN, Henrik; POPENbIU-VLDICESCU, Florin; DUMITRU, Marius, <i>ON DESIGNING EXTENDABLE JAVA-BASED SOFTWARE FOR TIME SERIES ANALYSIS</i><br> <b>Abstract</b>: Time series analysis is an important topic both for teaching statistics and research. The time series approach is used to predict future values based on the history of past values. Previous results in time series analysis methodologies, relevant applications and software development for time series analysis motivate us to promote a recently developed extendable Java-based tool for time series analysis. The software design methodology, the implemented algorithms and the extension methodology are detailed. <br> <b>Keywords</b>: <i>time series, extendable software, component-based development, Java</i> <br> <hr size="1"> <A name="2010-a6"><b>6.</b></a> STICLARU, Gabriel, <i>ALGEBRAIC STATISTICS: SOME APPLICATIONS</i><br> <b>Abstract</b>: A main purpose of this report is to present the connections between Algebra and Statistics, focused on the applications of Algebra in Statistics. We present applications in experimental designs and we exemplify by using the free computer algebra systems SINGULAR and CoCoA. <br> <b>Keywords</b>: <i>Algebraic Statistics, Gr&ouml;bner bases, Design of Experiments, Computer Algebra System</i> <br> <hr size="1"> <A name="2010-a7"><b>7.</b></a> PUNESCU, Luminica; CURCULESCU, Bogdan Ionuc, <i>INFORMATION SECURITY THROUGH WIRELESS TECHNOLOGY</i><br> <b>Abstract</b>: Wireless communications offer organizations and users a lot of benefits, portability and flexibility, increased productivity and lower installation costs. Wireless technologies cover a wide range of capabilities, targeted to users and their needs. Lack of wiring allows great flexibility, increased efficiency and reduced cabling costs, but there are inherent risks. Some are similar to those of wired networks, some are exacerbated by wireless connectivity, and some are new. Loss of privacy and integrity, threat and denial of service type attacks are risks normally associated to wireless communications. Unauthorized users can gain access to the information and the systems of an institution, can corrupt data, make full use of network bandwidth, degrade network performance, launch attacks that prevent authorized users from accessing the network, or use their resources to launch attacks on other networks. <br> <b>Keywords</b>: <i>Confidentiality, integrity, availability, authentication, access points, standards</i> <br> <a><div class="sepemptyw"></div></a> <span class="captitle">Analele Universitcii <i>Spiru Haret</i>, Seria Matematic-Informatic, V(special issue), 2009, Abstracts and Keywords</span> <hr size="1"> <A name="2009-s0"><b>0.</b></a> POPESCU, Ion; ALBEANU, Grigore, <i>MATHEMATICAL MODELLING IN BUSINESS, ENVIRONMENT, AND COMPUTER SCIENCE</i><br> <b>Abstract</b>: This note introduces eight papers presenting results obtained into the framework of the research direction "Results in theoretical mathematics, financial mathematics, actuarial mathematics, risk theory, applied mathematics in mechanics and social sciences" by the research group MATECON: "Applied mathematics in economy". The results were obtained based on intra and inter-university cooperation at national and international level. <br> <b>Keywords</b>: <i>CAMAI, modern investment theory, time series, dynamic financial analysis, bootstrap, queueing models, uncertainty estimation, statistics teaching, indirect </i> <br> <hr size="1"> <A name="2009-s1"><b>1.</b></a> MISCOI, Gheorghe; POPESCU, Ion; UNGUREANU, Laura; MATEI, Ion Viorel; VELTER, Victor, <i>ON INTERDISCIPLINARY APPROACH OF ECONOMIC REALITY</i><br> <b>Abstract</b>: This paper describes the first and second order models in modern investment theory. Interpretations of the decision processes are given and an application is described. <br> <b>Keywords</b>: <i>the accelerator model, investment adjustment costs, capital adjustment costs, the speed of adjustment, dynamic systems</i> <br> <hr size="1"> <A name="2009-s2"><b>2.</b></a> BURTSCHY, Bernard; ALBEANU, Grigore; POPENTIU-VLADICESCU, Florin, <i>TIME SERIES FORECASTING IN SOFTWARE RELIABILITY BY FUZZY NEAREST NEIGHBOUR METHOD</i><br> <b>Abstract</b>: Time series approach is used to predict future values based on the history of past values. This paper considers the usage of a fuzzy nearest neighbour method for time series forecasting. Not only sequential patterns in time series data are considered, but also the subsequences with some optimal size. <br> <b>Keywords</b>: <i>fuzzy logic, time-series, software reliability </i> <br> <hr size="1"> <A name="2009-s3"><b>3.</b></a> ALBEANU, Grigore; MADSEN, Henrik; GHICA, Manuela; POPENTIU-VLADICESCU, Florin, <i>BOOTSTRAP INTENSIVE METHODS FOR UNDERSTANDING EMPIRICAL LOSS DATA AND DYNAMIC FINANCIAL ANALYSIS</i><br> <b>Abstract</b>: Bootstrap Intensive Methods for estimation assessment provide valuable information concerning the adequacy of applied probabilistic models. The bootstrap method is an extensive computational approach for understanding empirical data and is based on resampling and statistical estimation. It is a powerful tool, especially when only a small data set is used to predict the behaviour of systems or processes. This paper describes some case studies based on the Efron type bootstrap approaches for modelling loss distributions and for general dynamic financial analysis. The case studies are inspired from risk management field. The research is based on theoretical previous developments in accuracy assessment, reliability estimation and risk exchange modelling. <br> <b>Keywords</b>: <i>bootstrap, loss distributions, dynamic functional analysis</i> <br> <hr size="1"> <A name="2009-s4"><b>4.</b></a> MADSEN, Henrik; POPENTIU-VLADICESCU, Florin; ALBEANU, Grigore, <i>QUEUEING MODELS FOR COMPUTING SYSTEMS MANAGEMENT AND MAINTENANCE</i><br> <b>Abstract</b>: Software development is a special activity typically carried out by individuals that work best on their own. Recently, it is full accepted that software products require documentation, testing, quality assurance and a complete understanding of customer requirements. Such activities are better carried under an efficient software management and by maintenance actions which do not increase the overall system cost. This paper presents some queueing models, successfully used for hardware service systems, in order to provide appropriate tools in the decision process related to resource allocation for developing, testing, and upgrading or maintaining the software under current exploitation. <br> <b>Keywords</b>: <i>queueing models, software management </i> <br> <hr size="1"> <A name="2009-s5"><b>5.</b></a> ALBEANU, Grigore; BURTSCHY, Bernard; POPENTIU-VLADICESCU, Florin, <i>ON DESIGNING EXTENDABLE JAVA-BASED SOFTWARE FOR TIME SERIES ANALYSIS</i><br> <b>Abstract</b>: This paper provides a methodology to investigate uncertainty evaluation by bootstrap and a procedure to obtain confidence bands for linear and nonlinear models used in data analysis and design measurements.<br> <b>Keywords</b>: <i>Bootstrap method, Resampling methods, Data modelling, Sampling variance, Median, Z-scores, Confidence Intervals, Confidence bands. </i> <br> <hr size="1"> <A name="2009-s6"><b>6.</b></a> MISCOI, Gheorghe; POPESCU, Ion; ALBEANU, Grigore; GHICA, Manuela, <i>ON TEACHING STATISTICS AND ECONOMETRICS USING MODERN ICT METHODOLOGIES</i><br> <b>Abstract</b>: This paper presents an approach on teaching statistics and econometry using modern ICT methodologies. Details on time series teaching and methods to prepare a statistics course are given.<br> <b>Keywords</b>: <i>ICT, E-learning, time series, statistics, applets, simulation</i> <br> <hr size="1"> <A name="2009-s7"><b>7.</b></a> ALBEANU, Grigore; BURTSCHY, Bernard; POPENTIU-VLADICESCU, Florin; GHICA, Manuela, <i>BOOTSTRAP SIMULATION MODELS IN ENVIRONMENTAL ECONOMICS</i><br> <b>Abstract</b>: This paper describes the usage of some bootstrap simulation models for modelling loss distributions and for general dynamic financial analysis applied in environmental economics. Two case studies, coming from forest economics, are presented. <br> <b>Keywords</b>: <i>bootstrap, LDA, DFA, loss distribution, regression, portfolio management</i> <br> <hr size="1"> <A name="2009-s8"><b>8.</b></a> MISCOI, Gheorghe; IOAN, Rodica; ALBEANU, Grigore, <i>BOOTSTRAP SIMULATION MODELS FOR INDIRECT MEASUREMENTS ESTIMATION</i><br> <b>Abstract</b>: This paper presents different bootstrap simulation models to be applied for some indirect measurement problems. These approaches are discussed and applied for uncertainty measurement in proficiency testing, time series, and reliability modelling. From computational point of view, the generalized inverse is required when using Quasi Gauss Newton Algorithms for solving nonlinear systems of equations. <br> <b>Keywords</b>: <i>bootstrap, Quasi Gauss Newton, generalized inverse</i> <br> <a><div class="sepemptyw"></div></a> <span class="captitle">Analele Universitcii <i>Spiru Haret</i>, Seria Matematic-Informatic, V(Issue 1), 2009, Abstracts and Keywords</span> <A name="2009-a1"> <hr size="1"> <b>1.</b></a> NICOLA, Ileana Rodica, <i>HOPF BIFURCATIONS FOR A TIME-DELAYED CANCER CELL POPULATION MODEL</i><br> <b>Abstract</b>: The paper investigates the structural stability of a cancer cell population time-delayed flow, establishing the critical value of the delay parameter that produces Hopf bifurcation. The model is investigated for three sets of values of the parameters. Numerical results are obtained using the software Maple 11. <br> <b>Keywords</b>: <i>dynamical system, time-delay, stationary point, Hopf bifurcation, quiescent cell population, proliferating cell population</i> <br> <hr size="1"> <A name="2009-a2"><b>2.</b></a> VÂRGOLICI, Horia, <i>AN ALGORITHM FOR THE SYNTHESIS OF THE FUNCTIONS GENERATOR CYLINDER MECHANISM</i><br> <b>Abstract</b>: The aim of this paper is to give an algorithm for the synthesis of the oscillating cylinder mechanism as a functions generator mechanism. <br> <b>Keywords</b>: <i>mechanism synthesis, oscillating cylinder mechanism</i> <br> <hr size="1"> <A name="2009-a3"><b>3.</b></a> GHICA, Manuela, <i>&epsilon;-APPROXIMATE PORTFOLIOS</i><br> <b>Abstract</b>: We propose some necessary and/or sufficient conditions with respect to scalarization for &epsilon;-efficiency, &epsilon;-weak efficiency and &epsilon;-proper efficiency portfolios for a reinsurance market in nonconvex optimization problem. <br> <b>Keywords</b>: <i>reinsurance market, portfolio, efficiency</i> <br> <hr size="1"> <A name="2009-a4"><b>4.</b></a> DUMITRU, Dan, <i>SOME ESTIMATIONS OF THE MANDELBROT SET</i><br> <b>Abstract</b>: The aim of this article is to give some estimations of the Mandelbrot set. We also compute how big is the radius of a ball contained entirely into the Mandelbrot set. <br> <b>Keywords</b>: <i>Julia sets, the Mandelbrot set</i> <br> <hr size="1"> <A name="2009-a5"><b>5.</b></a> VORNICESCU, Neculae, <i>A PROBLEM IN NONLINEAR OPTIMIZATION</i><br> <b>Abstract</b>: The continuous version of the "student optimal control problem" with control constraints is considered and improved theoretical results are provided. <br> <b>Keywords</b>: <i>nonlinear optimisation, optimal control</i> <br> <hr size="1"> <A name="2009-a6"><b>6.</b></a> NICULESCU, Rodica Florentina; NICULESCU, Radu ^tefan, <i>A CHARACTERIZATION OF DIRECTED <i>P</i>-GRAPHS</i><br> <b>Abstract</b>: In this paper we introduce directed <i>P</i>-graphs and <i>P<sub>k</sub></i>-graphs, as extensions of their previously studied undirected counterparts. The main result of this research computes the minimum number of edges of directed <i>P</i>-graphs and describes the structure of such minimal graphs. We establish a connection between this minimal structure and integer partitions, which allows us to exactly compute the number of distinct, non-isomorphic minimal directed <i>P</i>-graphs. We also characterize the density of the more general directed <i>P<sub>k</sub></i>-graphs relative to the entire set of graphs. <br> <b>Keywords</b>: <i>graph structure, minimal problems, density estimation</i> <br> <hr size="1"> <A name="2009-a7"><b>7.</b></a> MILITARU, Romulus; CLIN, Liviu-Adrian; CLUGRU, George-Cristian; GEORGESCU, Adrian, <i>EFFICIENT PROCESSING OF NUMERICAL ALGORITHMS THROUGH NUMERICAL ENGINEERING SOFTWARE</i><br> <b>Abstract</b>: Numerical Engineering Software represents a new software for solving technical problems through numerical algorithms. It consists of five chapters: Matrix Algebra, Polynomial Approximations, Roots of Equations, Numerical Integration and Cauchy Problems. As of March 2000, Numerical Engineering Software has been consistently upgraded to a new more complex version. We give a survey of this new version along with the basic features that are part of the Numerical Engineering Software project. <br> <b>Keywords</b>: <i>Matrix Algebra, Polynomial Approximations, Roots of Equations, Numerical Integration and Cauchy Problems</i> <br> <hr size="1"> <A name="2009-a8"><b>8.</b></a> MERCIER, Gilles; VÂLCU, Dana, <i>MULTIPROCESSOR SCHEDULING THEORY</i><br> <b>Abstract</b>: We survey the main problems induced by the real time multiprocessor scheduling, particularly emphasising the independent task model. Properties of scheduling independent tasks and implementation restrictions are presented, as well as their consequences. The relationship with the bin-packing problem is also considered. <br> <b>Keywords</b>: <i>scheduling, multiprocessing, on-line algorithm, complexity</i> <br> <hr size="1"> <A name="2008-a1"> <a><div class="sepemptyw"></div></a> <span class="captitle">Analele Universitcii <i>Spiru Haret</i>, Seria Matematic-Informatic, IV(Issue 1), 2008, Abstracts and Keywords</span> <hr size="1"> <b>1.</b></a> DUMITRU, Dan, <i>SOME GENERALIZATIONS OF F-CONNECTIONS ON DIFFERENTIABLE MANIFOLDS</i><br> <b>Abstract</b>: In this article we generalize the notion of F-connection, where F is an almost product structure on a manifold and we give some characterizations of the connections compatible with those structures. <br> <b>Keywords</b>: <i>(ap)-structure, F-connection</i> <br> <hr size="1"> <A name="2008-a2"><b>2.</b></a> VÂRGOLICI, Horia, <i>AN ALGORITHM FOR THE OPTIMAL SYNTHESIS OF A GUIDING MECHANISM</i><br> <b>Abstract</b>: The aim of this paper is to give a different method from the classic ones for the synthesis of the four-bar guiding mechanism. The method consists of the decomposition of the mechanism into small parts, simple kinematic chains, which are synthesized separately and then we put together the results, obtaining the synthesis of the whole mechanism. <br> <b>Keywords</b>: <i>optimal synthesis, guiding mechanism synthesis, simple cinematic chain </i> <br> <hr size="1"> <A name="2008-a3"><b>3.</b></a> BÂRZ, Silviu, <i>VARIATION OF CONSTANT SUM CONSTRAINT FOR INTEGER MODEL WITH NON UNIFORM VARIABLES</i><br> <b>Abstract</b>: This paper wants to continue the studies for a class of problems named constant sum integer programming introduced earlier. This approach tries to see what is happening when a variation appears in right hand of constant sum condition. In this paper I prove that limited variation influence no more than 3 model variables in model optimum and there is a way to say which these variables are. My consideration could be important if we want to transform a constant sum condition in a stochastic form. <br> <b>Keywords</b>: <i>linear programming, combinatorial optimization, percentage programming</i> <br> <hr size="1"> <A name="2008-a4"><b>4.</b></a> MIU, Lisandra, <i>DIFFERENT APPROACHES FOR A LINEAR MODEL FOR FINANCIAL PORTFOLIO OPTIMIZATION</i><br> <b>Abstract</b>: This paper tries to present a linear model for financial portfolio in different type of approaches and to decide which approach is closer to reality. The first approach I propose is to consider that all variables are of continuous type. The second one considers an integer linear program. The third approach uses a special class of combinatorial optimization. For each type of approach I give a possible way to find an optimal solution. Finally, I give two examples of financial portfolio and the forms of optimization model for all proposed approaches. <br> <b>Keywords</b>: <i>linear programming, integer linear programming, percentage optimization, financial portfolio</i> <br> <hr size="1"> <A name="2008-a5"><b>5.</b></a> MILITARU, Romulus; CLIN, Liviu-Adrian; CLUGARU, George-Cristian; GEORGESCU, Adrian, <i>NUMERICAL ENGINEERING SOFTWARE</i><br> <b>Abstract</b>: The Numerical Engineering Software represents an integrated solution for the implementation of a various number of numerical methods in order to obtain viable results to technical problems as fast as possible. The software focuses on the following topics: Matrix Algebra, Interpolation and Polynomial Approximation, Locating Roots of Equations, Numerical Integration and Initial Value Problems for Ordinary Differential Equations. The key features of this project are: the adjustable accuracy of computation, algorithms selection on computational cost criteria and ease of use (no programming abilities required) <br> <b>Keywords</b>: <i>linear systems, eigenvalues and eigenvectors, interpolation, numerical integration, Cauchy problems. </i> <br> <hr size="1"> <A name="2008-a6"><b>6.</b></a> STICLARU, Gabriel; DAN, Radu, Necolae; ISPAS, Marius, <i>E-COMMERCE WITH OPEN SOURCE TECHNOLOGY: Apache, PHP, and PostgreSQL </i><br> <b>Abstract</b>: Building an E-Commerce site requires a significant investment: time, money and lots of code (hundreds or thousands files). For a complete tutorial, we must write a book, but in this paper, we present only technical details. We concentrate on establishing the basic framework for the site, technologies, programming languages, and tools to reduce the initial investment. Our solution is to use only open source technology and multitier architecture. <br> <b>Keywords</b>: <i>open-source technology, E-Commerce, three-tier architecture, PHP, PostgreSQL.</i> <br> <hr size="1"> <A name="2008-a7"><b>7.</b></a> ALBEANU, Grigore; bARC, Ctlin Radu; POPENbIU-VLDICESCU, Florin; PA^C, Ildiko, <i>INTERFACING A ROBOT CONTROL APPLICATION WITH A REMOTE USER</i><br> <b>Abstract</b>: Mechatronics is an important field of science and technology providing a large spectrum of applications, being also an important educational discipline for engineers. Engineering education has special requirements, and the development of remote laboratories will be efficient not only considering costs of educational resources, but also offering simultaneously access to advanced technology. This paper describes recent developments in web-based tele-operation of robots. Different architectures offering remote interactivity were identified and a comparison is presented. Details on interfacing a Mitsubishi industrial robot with a remote user are presented in the framework of remote collaborative research and distance education in robotics. <br> <b>Keywords</b>: <i>remote robotics, client-server, remote laboratories, engineering distance education, Mitsubishi industrial robot control and programming</i> <br> <hr size="1"> <A name="2007-a1"> <a><div class="sepemptyw"></div></a> <span class="captitle">Analele Universitcii <i>Spiru Haret</i>, Seria Matematic-Informatic, III(Issue 1), 2007, Abstracts and Keywords</span> <hr size="1"> <b>1.</b></a> Copil, Vlad, <i>Relating the Riemann Hypothesis and the primes between two cubes</i><br> <b>Abstract</b>: In this paper we make an evaluation for the number of primes between two consecutive cubes, if we assume the Riemann hypothesis. There exists at least a prime between two consecutive cubes. More precisely, if we denote by N(n) the number of primes between (n-1)<sup>3</sup> and n<sup>3</sup>, then N(n) &asymp; n<sup>2</sup>/log n. <br> <b>Keywords</b>: <i>distribution of primes, the Riemann hypothesis</i> <br> <hr size="1"> <A name="2007-a2"><b>2.</b></a> Chicescu, Ion, <i>A formula concerning symmetric bilinear maps and self adjoint operators</i><br> <b>Abstract</b>: We prove a formula giving a limit in which continuous bilinear and symmetric functionals appear. Alternatively, the formula is expressed in terms of self adjoint operators. <br> <b>Keywords</b>: <i>symmetric bilinear map, self adjoint operator, differentiability</i> <br> <hr size="1"> <A name="2007-a3"><b>3.</b></a> Miu, Lisandra; Bârz, Silviu, <i>VaR methodology for currencies risk measurement</i><br> <b>Abstract</b>: This paper makes a short presentation of VaR methodology applied in portfolio for foreign currencies in agreement with Romanian National Bank rules. In the first part we present theoretical aspect of VaR methodology and NBR rules. In the end of this paper we give an application of VaR methodology for an imaginary portfolio with two currencies. <br> <b>Keywords</b>: <i>banking portfolio, statistics, foreign currencies</i> <br> <hr size="1"> <A name="2007-a4"><b>4.</b></a> Averian, Alexandru, <i>Component based systems testing with UML and incorporated contracts</i><br> <b>Abstract</b>: Production of complex systems done by reusing prefabricated software and hardware components has proved it's efficiency by accelerating the development process, significantly reducing development time and costs. Generally, the components are tested in their production environment, and the test elements are eliminated before publishing the component. The goal of testing based on incorporated contracts is to equip components with test elements which allow testing in the environment in which they are being developed and also if they are integrated in the development of other systems. <br> <b>Keywords</b>: <i> component-based sustems, UML models, test components, test interfaces, design for test</i> <br> <hr size="1"> <A name="2007-a5"><b>5.</b></a> Dochicoiu, ^tefan, <i>Algorithm and program to determine the order of a point on an elliptic curve</i><br> <b>Abstract</b>: This work presents an iterative algorithm and a program for obtaining the order of a point on an elliptic curve over a finite field. Details are given based on the Mathematica integrated development environment. <br> <b>Keywords</b>: <i>cyclic group, order of points, elliptic curve</i> <br> <hr size="1"> <A name="2007-a6"><b>6.</b></a> Tnase, Irina, <i>Software application for activities, clients and contracts management in a life insurance company</i><br> <b>Abstract</b>: Insurance companies generally have applications for the management of contracts and clients at a central level. There is also the necessity of developing applications that follow all the management process of clients, contracts and financial statistics from the point of view of the insurance agent/his manager. Because insurance agents and financial consultants travel a lot all around the country, it is desired to facilitate remote access - from distance to the database and own accounts. The software application implements Java technologies and it is a web application that gives access to information from the distance and offers an important statistical decisional support, by offering useful situations and reports. <br> <b>Keywords</b>: <i>web application, management, decisions, statistics, insurance company</i> <br> <hr size="1"> <A name="2007-a7"><b>7.</b></a> Sticlaru, Gabriel, <i>C++ classes to model financial instruments</i><br> <b>Abstract</b>: Our purpose is to use C++ to model financial instruments: Bonds, Stocks, Forwards, Futures, Options and Swaps. This paper concentrates on Options and presents an hierarchy of classes to model European Options, based on Black Scholes extended mathematical model, we calculate the price for Call and Put Option and some measures for sensitivities of the price: delta, gamma, vega, theta and rho. <br> <b>Keywords</b>: <i>financial instruments, European Options, Black and Scholes model, C++ classes.</i> <br> <hr size="1"> <A name="2007-a8"><b>8.</b></a> Rozoveanu, Petru, <i>The Clarke's subdifferential for vector valuated functions</i><br> <b>Abstract</b>: In this paper we examine the construction of Clarke's derivative for vector-valued functions. We use another kind of Lipscitz functions, which allow us to leave the context of normed spaces. As base of the generalization we use the approach used by Clarke for real functions. For vector-valued functions. Clarke uses the Rademacher theorem, which is not available in general contexts. <br> <b>Keywords</b>: <i>directional derivative, subdifferential, vectorial functions</i> <br> <hr size="1"> <A name="2007-a9"><b>9.</b></a> Rozoveanu, Petru, <i>A Perron-Frobenius theorem for nonlinear operators</i><br> <b>Abstract</b>: We extend a result of T. Fujimoto and U. Krause to infinite dimensional spaces, using a notion of strongly increasing operators which works also in spaces having the interior of the positive cone empty. <br> <b>Keywords</b>: <i>Perron-Frobenius theorem, nonlinear operators, Banach lattices</i> <br> <hr size="1"> <A name="2006-a1"> <a><div class="sepemptyw"></div></a> <span class="captitle">Analele Universitcii <i>Spiru Haret</i>, Seria Matematic-Informatic, II(Issue 1), 2006, Abstracts and Keywords</span> <hr size="1"> <b>1.</b></a> Rodica Trandafir, <i>Spiru Haret - om de ^tiinc / Spiru Haret - the Scientist</i><br> <b>Abstract</b>: <i>This paper presents some important aspects related to the life and scientific activity of Spiru Haret, and is based on the author's talk given with the ocasion of the scientiest celebration in 2006. </i><br> -----<br> <b>Rezumat</b>: Acest articol prezinta unele momente importante din viata si activitatea lui Spiru Haret si are la baza expunerea autoarei prilejuita de omagierea savantului in anul 2006.<br> <b>Cuvinte cheie</b>: <i>Spiru Haret, Mecanica cereasca, savant model</i> <br> <hr size="1"> <A name="2006-a2"><b>2.</b></a> ^tefan Costea, <i>Spiru Haret, Sociologia matematic ^i sociometria / Spiru Haret, Mathematical Sociology and Sociometrics</i><br> <b>Abstract</b>: <i>This paper presents the most important contributions of Spiru Haret to the study of the social laws and the sociological research method. The actual version is based on the author's talk given with the occasion of the scientiest celebration in 2006. </i><br> -----<br> <b>Rezumat</b>: Acest articol prezinta contributiile lui Spiru Haret in studiul legilor sociale si metoda de investigatie sociologica Haret si are la baza expunerea autorului prilejuita de omagierea savantului in anul 2006.<br> <b>Cuvinte cheie</b>: <i>Spiru Haret, Mecanica sociala, sociologie matematica</i> <br> <hr size="1"> <A name="2006-a3"><b>3.</b></a> Gabriel Dumitriu, <i>Asupra implementrii unui simulator generic / On the Implementation of a Generic Simulator</i><br> <b>Abstract</b>: <i>The author proposes a new implementation of general purpose simulators based on a modified DEVS formalism. This simulator is implemented as an object oriented library. This implementation offers to the users a method to implement new models with functionalities that don't have anything in common, except the interactions, without modify the library, or the implementation of an existed model. Currently, it was used to implement waiting systems and some event counter for testing purpose. </i><br> -----<br> <b>Rezumat</b>: Autorul propune o noua abordare a simulatoarelor generice pe baza formalismului DEVS modificat ca o continuare la implementarea inceputa teoretic in lucrarea "Florea I.L. <i>Upon Multiservers Preemptive Queueing System: A Formal and Object Oriented Approach"</i>. Aceasta abordare a fost implementata sub forma unei biblioteci de simulare orientata pe obiecte care sa permita utilizatorilor derivarea si implementarea unor noi modele pentru sisteme care nu au functional nimic in comun cu exceptia interactiunilor intre ele, fara a modifica o implementare existenta. In prezent a fost folosita in special pentru simularea sistemelor de asteptare.<br> <b>Cuvinte cheie</b>: <i>DEVS, general purpose simulator, GPSS, SIMUB</i> <br> <hr size="1"> <A name="2006-a4"><b>4.</b></a> Argus Adrian Dunca, <i>O nou tehnic de filtrare pentru simularea numeric a fluidelor turbulente / A New Filtering Technique for the Turbulent Flows' Numerical Simulation</i><br> <b>Abstract</b>: <i>This paper presents a new LES technique having a better approximation accuracy than the Differential Filters Method described in [9]. The present method can be used jointly with ADM [1, 2] to improve the Stolz-Adams' methods for turbulent flows. </i><br> <b>Selected references</b>: <br> 1. N.A. Adams, S. Stolz. <i>On the Approximate Deconvolution Procedure for LES</i>. Phys. Fluids, II:1699-1701, 1999.<br> 2. N.A. Adams, S. Stolz. <i>Deconvolution Methods for Subgrid-scale Approximation in Large-Eddy Simulation</i>. Modern Simulation Strategies for Turbulent Flow. R.T. Edwards, 2001.<br> 9. M. Germano. <i>Differential Filters of Elliptic Type</i>. Phys. Fluids, 29: 1757-1758, 1986. -----<br> <b>Rezumat</b>: In aceasta lucrare este prezentata o noua tehnica de filtrare in LES ce are o acuratete mai mare in aproximare decat metoda de filtrare cu filtri diferentiali prezentata in [9]. Aceasta metoda poate fi utilizata impreuna cu metoda de deconvolutie aproximativa, ADM prezentata in [1, 2], pentru imbunatatirea modelelor Stolz-Adams pentru fluide turbulente. Derivarea matematica a noilor modele este de asemenea prezentata.<br> <b>Cuvinte cheie</b>: <i>LES (large eddy simulation), FEM (finite element methods), ADM (approximate deconvolution methods)</i> <br> <hr size="1"> <A name="2006-a5"><b>5.</b></a> Aurora Baciu, <i>Limbaje Leontief probabiliste / Probabilistic Leontief Languages</i><br> <b>Abstract</b>: <i>This paper introduces the probability for Leontief grammars studied in [1] defining the probabilistic Leontief grammars generating probabilistic Leontief languages. Two closing properties are studied. </i><br> -----<br> <b>Rezumat</b>: In articol se introduce notiunea de probabilitate la gramaticile Leontief studiate in [1] definind gramaticile Leontief probabiliste care genereaza limbaje Leontief probabiliste. Pentru aceste limbaje se studiaza doua proprietati de inchidere.<br> <b>Cuvinte cheie</b>: <i>gramatica Leontief probabilista, limbaj Leontief probabilist </i> <br> <b>Selected reference</b>:<br> 1. Baciu A., Pascu A., <i>Leontief Type Grammars and Languages</i>, Foundations of Control Engineering, Nr. 3, Vol. 1, (1979), 91-106. <hr size="1"> <A name="2006-a6"><b>6.</b></a> Silviu Bârz, <i>Modele întregi cu sum constant ^i variabile cu domeniu uniform / Constant Sum Integer Models with Uniform Domain Variables</i><br> <b>Abstract</b>: <i>This paper presents a class of problems viewed as percentage programming as was introduced earlier. We start from a particular integer programming problems covered by polyhedral linear problem. Our consideration could be important as a better algorithm based on percentage programming properties as was already described. </i><br> -----<br> <b>Rezumat</b>: Lucrarea de fata este o abordare prin programarea procentuala a unei probleme clasice din optimizarea combinatoriala, si anume problema de tip rucsac, data intr-un caz particular al problemei generale, altul decat cazul rucsacului 0-1. Se arata ca, in conditiile speciale ale programarii procentuale, exista un procedeu de reducere a problemei, care prin repetare poate constitui un algoritm eficient de rezolvare a problemei considerate.<br> <b>Cuvinte cheie</b>: <i> programare liniara, optimizare combinatoriala, programare procentuala</i> <br> <hr size="1"> <A name="2006-a7"><b>7.</b></a> Antonela Gonciulea, <i>Determinarea coeficiencilor omogenizaci pentru o ecuacie de tip eliptic / Homogenized Coefficients Determination for an Elliptic Equation</i><br> <b>Abstract</b>: <i>The theoretic researches that took place until the present have lead to the elaboration of a number of methods of homogenization concerning the behavior of certain heterogeneous materials obtained as mixtures of materials with well defined properties. For elliptical equations, the goal is to obtain an asymptotic development of the solution, which allows us to calculate the homogenized coefficients. The mathematical model which illustrates the homogenizing method in the clearest manner is a composite material. It is obtained by introducing certain fibers or inclusions from a material with better resistance properties in a matrix with very poor mechanical properties. The limit to which the solution of the considered equation tends to and the equation which this limit checks out (with some coefficients being different from the limit of those from which we started) represents the macroscopic behavior of the composite material. <br> By introducing the small parameter the initial problem is included in a parameterized family of problems and we will study the behavior of the solution when &epsiolon; goes to 0. From a mechanical point of view, this means describing the transition from local or microscopic study of the phenomenon to macroscopic study. In (1.3) A is an operator with constant coefficients, called a homogenized operator, and the meaning of this terminology must be understood in this way: u<sup>0</sup> , which satisfies an equation with constant coefficients approximates the solution u<sup>&epsilon;</sup> which is very difficult to calculate. Thus, the dependency for microscopic structure is obtained using homogenized coefficients. </i><br> -----<br> <b>Rezumat</b>: Cercetarile teoretice de pana in prezent au dus la elaborarea mai multor metode de omogenizare privind comportarea unor materiale eterogene obtinute ca amestecuri de materiale cu proprietati bine definite. In cazul ecuatiilor de tip eliptic se incearca obtinerea unei dezvoltari asimptotice a solutiei, ce permite calculul coeficientilor omogenizati.<br> <b>Cuvinte cheie</b>: <i>omogenizare, coeficienti omogenizati,ecuatie macroscopica</i> <br> <hr size="1"> <A name="2006-a8"><b>8.</b></a> Manuela Ghica, <i>Portofolii optime în finance ^i actuariat / Optimal Portfolios in Finance and Actuarial Science</i><br> <b>Abstract</b>: <i>This paper starts with a paragraph which presents a classical portfolio selection model and the problems must be solved by an investitor when he wants to make an investment decision. In the following we present some results for a standard risk sharing model of reinsurance markets. In the end we consider the case of marginal mixture exponential utility functions. </i><br> -----<br> <b>Rezumat</b>: In acest articol sunt prezentate cateva rezultate privind portofoliile optime atat pentru o piata financiara cat si pentru o piata de asigurari cand functia de utilitate este o mixtura exponentiala.<br> <b>Cuvinte cheie</b>: <i>portofoliu, rentabilitate, activ financiar, divident, portofoliu optim, echilibru competitional.</i> <br> <hr size="1"> <A name="2006-a9"><b>9.</b></a> Luciana Maria Morogan, <i>Codificarea Informaciei în noile modele de calcul. Calcul bazat pe ADN ^i calculul cu membrane celulare / Information Coding in the new Computational Models. DNA based Computing and Membrane Computing</i><br> <b>Abstract</b>: <i>Researchers considered the DNA and the cell membranes as devices for the storage of genetic material. Recently, they implemented the storage of huge quantities of information in DNA and more recently, in some abstract devices called membranes systems, known as well as P systems - called after their inventor, prof. dr. Gh. Paun. This paper presents the necessary terminology of understanding the new concepts in section 2, called "general remarks". Those two different categories: of writing the information into DNA and of coding the information into the membrane structure using multisets of atomic objects, are presented in sections 3 and 4, respectively. In section 3 are presented the solid and the liquid faze of writing the information in the DNA sequences along with the constraints necessary for such processes. A totally different aproach is illustrated in the next chapter, because in the base model we don't have to deal with sequences, as in DNA computing, but with multisets of atomic objects, as we have already explained. This is where the differences between two nature based aproches, of coding the information, actually differ. What really maters here, is not the sintax of the membrane model, who totally differ of the DNA based model, but the numerical vectors, that characterized the multiplicity of object copies belonging of certains regions. Some of those conlusions are presented in the last section of this paper. </i><br> -----<br> <b>Rezumat</b>: Cercetari recente, au considerat atat ADN-ul cat si membranele celulare, drept medii pentru calculul la scara mare dar si pentru stocarea ultra compacta a informatiei (ADN-ul actioneaza drept mecanism de stocare si codificare a informatiei genetice, desi nu este folosit direct in catalizarea proceselor celulare, ci, mai degraba, ARN-ul si proteinele actioneaza drept enzime ce catalizeaza reactiile din interiorul celulelor). Lucrarea de fata insumeaza un colaj de modele de codificare a informatiei (colaj realizat in urma cercetarii printre lucrarile scrise pana in prezent) privite din perspectiva a doua noi modele de calcul inspirate de micro-biologie: calculul bazat pe ADN si calculul folosind P-sisteme (realizat pentru reprezentarea unara a unui numar intreg pozitiv scris sub forma binara).<br> <b>Cuvinte cheie</b>: <i>DNA computing, membrane computing, P systems</i> <br> <hr size="1"> <A name="2006-a10"><b>10.</b></a> Rodica Trandafir, <i>Valori medii ale unor variabile aleatoare din planul euclidian E<sub>2</sub> / Mean Values for Euclidian E<sub>2</sub> Random Variables</i><br> <b>Abstract</b>: <i>This paper presents computing results concerning the mean value of random variables associated to some families of convex shapes beloging to the Euclidian space E<sub>2</sub>. </i><br> -----<br> <b>Rezumat</b>: In aceasta lucrare se calculeaza valorile medii ale unor variabile aleatoare atasate unor familii de figuri convexe din planul euclidian E<sub>2</sub>.<br> <b>Cuvinte cheie</b>: <i>figuri convexe, valori medii</i> <br> <hr size="1"> <A name="2006-a11"><b>11.</b></a> Gabriel Sticlaru, <i>Dezvoltarea unui sistem de tranzaccionare / The Development of a Transactional System</i><br> <b>Abstract</b>: <i>This article explains how we could develop a trading system, which may allow us configuring and personalizing it, according to the user needs. The central component is a trading top soft like Metastock, with which experienced developers can integrate their own customized trading solutions using API. We present how to decode the data format, supply historical data, and create new technical indicators, explorations and external library. The purpose is to make the trading automatic through collecting the signals (alerts) and preparing the selling/buying decision. </i><br> -----<br> <b>Rezumat</b>: Articolul explica cum putem dezvolta un sistem de tranzactionare care sa permita configurare si personalizare conform nevoilor utilizatorului. Componenta principala este un soft de analiza tehnica de top, de exemplu Metastock, cu care dezvoltatorii experimentati pot sa-si integreze propriile solutii de tranzactionare folosind interfata API. Se prezinta modul de decodificare si colectare a datelor de bursa, crearea de noi indicatori tehnici, filtre si biblioteci externe. Dezvoltarea sistemului are ca scop automatizarea tranzactiilor prin obtinerea de semnale (alerte) si fundamentarea deciziei de vanzare/cumparare.<br> <b>Cuvinte cheie</b>: <i>Metastock format, Indicatori tehnici, FTP Downloader, MDK (Metastock Developer Kit), tranzactii bursiere</i> <br> <hr size="1"> <A name="2006-a12"><b>12.</b></a> Florentina-Rodica Niculescu, Radu-^tefan Niculescu, <i>Extinderi ale nociunii de P-graf relativ la grafuri neorientate / P-graph Extensions for Non-directed Graphs</i><br> <b>Abstract</b>: <i>In this paper we introduce undirected Pk-graphs and undirected Qk-graphs, two generalizations of P-graphs. The main results of this research describe the minimum number of edges of such graphs. We also characterize the density of such graphs relative to the entire set of graphs. A similar density result is proved for matrix labirinths which have the property that one can find an exit path from any given position. </i><br> -----<br> <b>Rezumat</b>: Aceasta lucrare introduce clasele de grafuri neorientate Pk-graf si Qk-graf si prezinta doua generalizari pentru grafuri P. Principalele rezultate se refera la numarului minim de muchii ale acestor muchii. Deasemenea, este caracterizata densitatea acestor grafuri relativ la multimea tuturor grafurilor. Un rezultat similar privind densitatea este demonstrat pentru labirinturile matriciale care au proprietatea ca se poate gasi o iesire din orice pozitie.<br> <b>Cuvinte cheie</b>: <i>Grafuri, conexitate, P-Grafuri, labirinturi</i> <br> <hr size="1"> <A name="2005-a1"> <a><div class="sepemptyw"></div></a> <span class="captitle">Analele Universitcii <i>Spiru Haret</i>, Seria Matematic-Informatic, I(Issue 1), 2005, Abstracts and Keywords</span> <hr size="1"> <b>1.</b></a> Aurora Baciu, <i>Gramatici contextuale R-fuzzy / R-fuzzy contextual grammars</i><br> <b>Abstract</b>: <i>In this paper is presented a new fuzzification of contextual grammars introduced by Solomon Marcus. One takes as algebraic structures of the set of truth values the structures defined by W. Wechler. The notion of total R-fuzzy algebra is introduced and it is shown that the hierarchy obtained within these algebras extends the generative capacity of contextual grammars. </i><br> -----<br> <b>Rezumat</b>: In aceasta comunicare se prezinta o noua fuzzificare a gramaticilor contextuale introduse de Solomon Marcus. Se iau ca structuri algebrice ale multimii valorilor de adevar structurile definite de W. Wechler. Se introduce notiunea de algebra R-fuzzy totala si se arata ca ierarhia obtinuta cu aceste algebre extinde capacitatea generativa a gramaticilor contextuale.<br> <b>Cuvinte cheie</b>: <i>gramatici contextuale fuzzy, limbaj contextual fuzzy, algebr fuzzy, semiinel parcial ordonat</i> <br> <hr size="1"> <A name="2005-a2"><b>2.</b></a> Marin Popa, Mariana Popa, <i>Invarianci si S-invarianci într-o PT-recea Petri / Invariants and S-invariants in a marked PT-Petri net</i><br> <b>Abstract</b>: <i>After a short introduction to the theory of systems, in general, and of Petri Nets in particular, the article begins woth a characterization theorem of invariants of a marked and {0, 1}-valued Petri net using the flux relation of the network. It then continues with a structural characterization of the network's invariants using its incidence operator, a characterization of S-invariants of a live Petri net, a sufficient condition of bounding a covered Petri net using invariants, etc. The article ends by presenting a concrete way of studying the properties of a system using S-invariants of the Petri net that models that system. The object in question is an operating system with n input and output processes that share a common buffer. </i><br> -----<br> <b>Rezumat</b>: Articolul prezent stabileste o serie de proprietati legate de invariantii si S-invariantii unei retele Petri marcate, asa cum ar fi: o caracterizare structurala a invariantilor unei PT - retele Petri marcate si {0, 1}-valuate prin intermediul retelei de flux a retelei, o caracterizare structurala a invariantilor retelei prin operatorul de incidenta al acesteia, o caracterizare a S-invariantilor unei retele Petri viabile, o conditie suficienta de marginire a unei retele Petri acoperita prin S-invarianti, etc. Articolul se incheie prin prezentarea unei modalitati concrete de studiere a proprietatilor unui sistem prin intermediul S-invariantilor retelei Petri care modeleaza acel sistem.<br> <b>Cuvinte cheie</b>: <i>recea Petri marcat, invariant, S-invariant, viabilitate, mrginire </i> <br> <hr size="1"> <A name="2005-a3"><b>3.</b></a> Rodica Ioan, <i>Utilizarea metodei perturbaciilor la rezolvarea problemei tragerii benzilor folosind o teorem de medie / The problem of strip drawing through a converging die using a local method</i><br> <b>Abstract</b>: <i>In this paper is approached the problem of strip drawing through a converging die using a local method, the method of perturbation series with respect to a small parameter-Bingham's number, as it was used in several papers. Here the solution of the problem is less complicated using a theorem of mean value and the results obtained are practically identical with the results given in [1]. </i><br> -----<br> <b>Rezumat</b>: Aceasta comunicare prezinta o solutie a problemei tragerii benzilor utilizand o teorema de medie, care permite simplificarea semnificativa a problemei. Rezultatele obtinute sunt practic identice cu cele din lucrarea [1].<br> <b>Cuvinte cheie</b>: <i>metoda perturbaciilor, numrul Bingham, tragere benzi, teorem de medie, tensiune de tragere</i> <br> [1] N. Cristescu, I. Suliciu, Vîscoplasticitate, Ed. Tehnic, Bucure^ti, 1976.<br> <hr size="1"> <A name="2005-a4"><b>4.</b></a> Lorena Tufan, <i>H*-Algebre / H* - algebra</i><br> <b>Abstract</b>: <i>This paper treats the problem of H*-algebra. This concept was introduced and studied by Ambrose in the associative case and then the theory was extended by Lee and Jordan in nonassociative case. The paper contents two paragraphs: 1) H*-algebra with involution; 2) The construction of some H*-algebras. </p>The first paragraphs starts with the definition of a H*-algebra, goes on with some properties of it and ends with an important theorem which says that any H*-algebra is an orthogonal summ of closed ideals. </p> <p>The second paragraph contents two parts: in the first one are presented two exemples of H*-algebra (the tensorial product of algebras and the matrix algebra). In the second one are introduced the notions of Springer H*-algebra and structurable H*-algebra, some of their presents and a result which says that if we have a Springer H*-algebra we can construct a simple topological structurable H*-algebra. </p></i> -----<br> <b>Rezumat</b>: In aceasta comunicare in primul paragraf voi demonstra ca orice H*-algebra este o suma ortogonala de ideale inchise, iar in al doilea paragraf voi prezenta constructia unor H*-algebre. <br> <b>Cuvinte cheie</b>: <i>produs scalar, topologie, ideal inchis, spatiu Hilbert </i> <br> <hr size="1"> <A name="2005-a5"><b>5.</b></a> Marina Cidot, <i>Tehnici predictive în procesarea semnalului vorbit / Prediction techniques processed in speech signal</i><br> <b>Abstract</b>: <i>Speech signal has statistically non-stationary properties and cannot be processed properly by the use of classical linear parametric models (AR, MA, ARMA). The neural network approach to time series prediction is suitable for learning and recognizing the nonlinear nature of the speech signal. We present three types of learning algorithms for recurrent neural networks for prediction and test them on two classes of speech signal spoken by both men and women in different dialects of English language. </i><br> -----<br> <b>Rezumat</b>: Semnalul vorbit este nestationar si din acest motiv nu poate fi modelat cu ajutorul modelelor liniare parametrice clasice (AR, MA, ARMA). Aplicarea retelelor neurale recurente in domeniul predictiei seriilor dinamice este potrivita pentru invatarea si recunoasterea structurii neliniare a semnalului vorbit. Prezentam trei tipuri de algoritmi de antrenare a retelelor recurente pentru predictie si rezultatele testelor efectuate pe doua clase de semnale, rostite atat de femei cat si de barbati in diferite dialecte ale limbii engleze.<br> <b>Cuvinte cheie</b>: <i>Tehnici predictive în procesarea semnalului vorbit, recele recurente neurale</i> <br> <hr size="1"> <A name="2005-a6"><b>6.</b></a> Gabriel Dimitriu <i>Asupra utilizrii unor mecanisme formale în descrierea proceselor de a^teptare specifice sistemelor client-server / About the utilization of formal languages in the description of the waiting processes specific to the client-server applications</i><br> <b>Abstract</b>: <i>In this paper we present the waiting process modeling that appear in client-server applications with the help of formal language theory and of NFA/DFA structures for a particular application. </i><br> -----<br> <b>Rezumat</b>: Aceasta comunicare abordeaza modelarea proceselor de asteptare care intervin in cadrul aplicatiilor client-server cu ajutorul teoriei limbajelor formale si a structurilor AFN/AFD. Exemplificarea este realizata pentru o aplicatie particulara.<br> <b>Cuvinte cheie</b>: <i>gramatici formale, automate, client-server, modelare parcial ordonat</i> <br> <hr size="1"> <A name="2005-a7"><b>7.</b></a> Marin Popa, Mariana Popa, <i>Calculul unor msuri necesare cutrii pe web / Computing some measures for WEB search</i><br> <b>Abstract</b>: <i>In this article we define a couple of measures that facilitate WEB page searching, including: the importance (degree) of a page, the relative degree of a block, the indexing and authority degree of a page, etc. For this we consider the WEB as being a great digraph in which nodes correspond to pages and arcs corresponds to links. also, we consider the WEB as a digraph where nodes are WEB domains and arcs are links between pages on those domains. We compute the defined measures first on a domain level, then intra-domain and then globally, by concatenation, on a WEB level. </i><br> -----<br> <b>Rezumat</b>: In articol se definesc cateva masuri necesare pentru a usura cautarea pe WEB si se prezinta modalitati eficiente de calcul al acestor structuri.<br> <b>Cuvinte cheie</b>: <i>gradul sau importanta unei pagini, index, autoritate, grad de indexare, grad de autoritate, grad relativ al unui bloc </i> <br> <hr size="1"> </td> <td width="190" style="vertical-align:top; border-left:solid 1px #eeeedd; padding-left:20px; padding-right:20px; background-color:#ffffee;"> <!-- #A69C8F --> <!-- <hr size="1" color="#aaaaaa"> --> <br> <!-- <form method="post" action="aaa.php" width="150" > <input class="search" type="text" name="username" value="" ><br> <input class="search" type="submit" name="submit" value="Search"> <a><div class="sepline"></form></div></a> <a><div class="sepempty"></div></a> --> <a href="http://fmi.spiruharet.ro/annals/" style="text-decoration:none"><div class="adef" onmouseover="cfmover(this);" onmouseout="cfmout(this);" >Current Issue</div></a> <a href="http://fmi.spiruharet.ro/annals/archive.html" style="text-decoration:none"><div class="adef" onmouseover="cfmover(this);" onmouseout="cfmout(this);" >Journal Archive</div></a> <a href="http://fmi.spiruharet.ro/annals/abstracts.html" style="text-decoration:none"><div class="adef" onmouseover="cfmover(this);" onmouseout="cfmout(this);" >All Abstracts</div></a> <div class=adeflj></div> <div class=adefls></div> <a href="http://fmi.spiruharet.ro/annals/cfp.html" style="text-decoration:none"><div class="adef" onmouseover="cfmover(this);" onmouseout="cfmout(this);" >Call For Papers</div></a> <a href="http://fmi.spiruharet.ro/annals/cfp.html#instructions" style="text-decoration:none"><div class="adef" onmouseover="cfmover(this);" onmouseout="cfmout(this);" >Instructions for Authors</div></a> <a href="http://fmi.spiruharet.ro/annals/cfp.html#epolicy" style="text-decoration:none"><div class="adef" onmouseover="cfmover(this);" onmouseout="cfmout(this);" >Editorial Policy / Paper Lifecycle</div></a> <div class=adeflj></div> <div class=adefls></div> <a href="http://fmi.spiruharet.ro/annals/about.html" style="text-decoration:none"><div class="adef" onmouseover="cfmover(this);" onmouseout="cfmout(this);" >Journal Description</div></a> <a href="http://fmi.spiruharet.ro/annals/about.html#board" style="text-decoration:none"><div class="adef" onmouseover="cfmover(this);" onmouseout="cfmout(this);" >Editorial Board</div></a> <a href="http://fmi.spiruharet.ro/annals/about.html#contact" style="text-decoration:none"><div class="adef" onmouseover="cfmover(this);" onmouseout="cfmout(this);" >Contact</div></a> <a><div class="sepline"></div></a> <a><div class="sepempty"></div></a> <!-- <form method="post" action="aaa.php"> <input class="trimite" type="text" name="username" value="Username" ><br> <input class="trimite" type="text" name="password" value="password" ><br><br> <input class="trimite" type="submit" name="submit" value="Login"> </form> <div class="sepline"></div> <br>&nbsp; --> <img src="http://fmi.spiruharet.ro/annals/img/c-mica.jpg" width="148" style="border-bottom:solid 1px black; border-right:solid 1px black; border-left:solid 1px #aaaaaa; border-top:solid 1px #aaaaaa;"> <a><div class="sepline"></div></a> <a><div class="sepempty"></div></a> <img src="http://fmi.spiruharet.ro/annals/img/ic.gif" width="148" style="border-bottom:solid 1px black; border-right:solid 1px black; border-left:solid 1px #aaaaaa; border-top:solid 1px #aaaaaa;"> <a><div class="sepline"></div></a> <a><div class="sepempty"></div></a> </td> </tr> </table> </td> </tr> </table> </td> <td style="width:10%;"> </td> </tr> <tr> <td><!-- 10% --></td> <td style="padding-top:5px; padding-bottom:5px; text-align:center; background-color:#3366aa;border-top-style:solid 2px;"> <font style="color:bisque; font-family:verdana; font-size:8pt;">Site created by <a style="color:white" href="http://fmi.spiruharet.ro/annals/webteam.html">AICL Lab. 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