Informatica Economica Vol. 13 No. 3/2009

Issue Topic: Multimedia Technologies


Exploring Multimedia Web Conferencing
Ana-Maria SUDUC, Mihai BÎZOI, Florin Gheorghe FILIP 5
Internet changed the perspective on meetings and also on decision making processes. Virtualization of meetings has become a common way for collaboration among employees, customers, partners, trainees and trainers, etc. Web conferencing allows the collaboration between teams’ members to achieve common goals. Without the need of travelling and meeting organization, the web conferencing applications permit the participation of people from different location. Web conferencing applications are multimedia systems that allow various remote collaborations with multiple types of resources. The paper presents an exploratory study on multimedia web conferencing systems, its advantages and disadvantages and also a use case, meant to highlight several of this technology benefits and problems.
Keywords: multimedia web conferencing, web collaboration, virtual teams, decision support

Principles of Multimedia News Systems for Business Applications
Ioan I. ANDONE 18
In the past few years considerable demand for business oriented multimedia information systems has developed. A multimedia information system is one that can create, import, integrate, store, retrieve, edit, and delete two or more types of media materials in digital form, such as audio, image, full-motion video, and text information. Multimedia information systems play a central role in many business activities. They represent a very special class complex computing systems. This paper surveys a special type of multimedia information systems: multimedia news systems. Multimedia news systems deal with architectures to manage complex multimedia news databases, online presentation and distribution services or the integration of several existing services to meta-services using intelligent news retrieval engines. The leading presentation platform in multimedia news presentation is news networks providing television services and Internet content distribution. The primary focus is on advanced multimedia news systems infrastructure, document standards, application architecture and principles for multimedia news on the Web that suggest long-term trends in this increasingly important area.
Keywords: multimedia, information systems, business applications

Multimedia technologies and Virtual Organizing of Learning
Grigore PIROSCĂ, Florina MOHANU 26
This paper addresses the issue of what are the efficient uses of multimedia technologies in teaching processes, and what are the conditions that require these technologies in online learning. The background of this paper is made by exploring online master programs, given the burgeoning interest of this emerging phenomenon of the future of distance learning. Rigorous analysis and careful measurement of communication required were covered by empirical data. This analysis is to provide an early window into several communications processes and tasks that occur in virtual context of learning, using multimedia technologies.
Keywords: multimedia technologies, virtual organization, online learning, communication, effectiveness of learning

Multimedia and decision-making process
Ovidiu-Alin DOBRICAN 36
Multimedia technology has changed the way we use computers. Multimedia transforms computers into a second person. Multimedia technology has made it possible for us to see, hear, read, feel, and talk to computers. Multimedia technology has transformed our use and understanding of computers. On the other hand, multimedia presentation is one of the fastest-growing sectors of the computer industry. Applications have appeared in many areas, such as training, education, business presentation, merchandising, and communications.
Keywords: multimedia, decision, studies, mining, architecture

Numerical Methods for Obtaining Multimedia Graphical Effects
Alexandru SMEUREANU, Stefan Daniel DUMITRESCU  49
This paper is an explanatory document about how several animations effects can be obtained using different numerical methods, as well as investigating the possibility of implementing them on very simple yet powerful massive parallel machines. The methods are clearly described, containing graphical examples of the effects, as well as workflow for the algorithms. All of the methods presented in this paper use only numerical matrix manipulations, which usually are fast, and do not require the use of any other graphical software application.
Keywords: raster graphics, numerical matrix manipulation, animation effects

Multimedia Flavor in Directory Services Environment
Emanuil REDNIC, Andrei TOMA 59
The present article aims to present the extended functionality of LDAP based systems (known as Directory Services) of handling multimedia information such as photographs. The most frequently used are JPEG encoded photos. Furthermore this article will explain how this multimedia functionality can be used to increase the security of identity management based systems.
Keywords: database security, distributed activities, multimedia information, multimedia processing, watermarking

A Comparison of Quantitative and Qualitative Data from a Formative Usability Evaluation of an Augmented Reality Learning Scenario
Dragoş Daniel IORDACHE, Costin PRIBEANU 67
The proliferation of augmented reality (AR) technologies creates opportunities for the development of new learning scenarios. More recently, the advances in the design and implementation of desktop AR systems make it possible the deployment of such scenarios in primary and secondary schools. Usability evaluation is a precondition for the pedagogical effectiveness of these new technologies and requires a systematic approach for finding and fixing usability problems. In this paper we present an approach to a formative usability evaluation based on heuristic evaluation and user testing. The basic idea is to compare and integrate quantitative and qualitative measures in order to increase confidence in results and enhance the descriptive power of the usability evaluation report.
Keywords: augmented reality, multimodal interaction, e-learning, formative usability evaluation, user testing, heuristic evaluation

A Survey on Multimedia Technologies for Mobile Learning Applications
Paul POCATILU, Cătălin BOJA  75
Mobile technologies are developing very fast. This paper presents a survey on multimedia technologies for mobile learning applications, focusing on multimedia programming techniques for Windows Mobile, Symbian, and Java ME.
Keywords: multimedia, mobile devices, mobile applications, mobile learning

Generating Multimedia Components for M-Learning
The paper proposes a solution to generate template based multimedia components for instruction and learning available both for computer based applications and for mobile devices. The field of research is situated at the intersection of computer science, mobile tools and e-learning and is generically named mobile learning or M-learning. The research goal is to provide access to computer based training resources from any location and to adapt the training content to the specific features of mobile devices, communication environment, users’ preferences and users’ knowledge. To become important tools in education field, the technical solutions proposed will follow to use the potential of mobile devices.
Keywords: M-learning, mobile devices, MPEG-21 standard, multimedia databases

A Capacity Supply Model for Virtualized Servers
Alexander PINNOW, Stefan OSTERBURG 96
This paper deals with determining the capacity supply for virtualized servers. First, a server is modeled as a queue based on a Markov chain. Then, the effect of server virtualization on the capacity supply will be analyzed with the distribution function of the server load.
Keywords: Markov chain, Weibull distribution, server, capacity supply

Importance Sampling for a Markov Modulated Queuing Network with Customer Impatience until the End of Service
Ebrahim MAHDIPOUR, Amir Masoud RAHMANI, Saeed SETAYESHI 106 
For more than two decades, there has been a growing of interest in fast simulation techniques for estimating probabilities of rare events in queuing networks. Importance sampling is a variance reduction method for simulating rare events. The present paper carries out strict deadlines to the paper by Dupuis et al for a two node tandem network with feedback whose arrival and service rates are modulated by an exogenous finite state Markov process. We derive a closed form solution for the probability of missing deadlines. Then we have employed the results to an importance sampling technique to estimate the probability of total population overflow which is a rare event. We have also shown that the probability of this rare event may be affected by various deadline values.
Keywords: Importance Sampling, Queuing Network, Rare Event, Markov Process, Deadline

A Missing Piece of RSS Technology
In the Information Age, people use RSS (Really Simple Syndication) Technology to help them to easily get the latest contents from websites by accessing only a single website as well as by using mobile devices. Several companies have started to use RSS for distributing their information to customers. However, most contents published via RSS technology are public and not confidential such as credit card information, financial business information etc. Since the RSS technology does not have a mechanism to ensure that the incoming information is really secure, in this paper we have proposed a Secure Information Notifying System with RSS Technology (SInfoNS). We have applied the RSS technology together with the cryptography to make any RSS document become secure before disseminating it to relevant users. The SInfoNS also uses XSL to apply to private information retrieval and XML schema and SchemaPath definitions have been created for validation. The results displayed on a user’s mobile device provide users with the latest information. The results of this study confirm that our system will aggregate RSS documents and disseminate information to each user. The SInfoNS enables RSS technology for the use of private information that can be securely distributed.
Keywords: Cryptography, Really Simple Syndication, RSS, XML Schema, XSL

Web Mining Functions in an Academic Search Application
This paper deals with Web mining and the different categories of Web mining like content, structure and usage mining. The application of Web mining in an academic search application has been discussed. The paper concludes with open problems related to Web mining. The present work can be a useful input to Web users, Web Administrators in a university environment.
Keywords:  Database, HITS, IR, NLP, Web mining

Orthogonally Based Digital Content Management Applicable to Projects-bases
Ion IVAN, Andrei SANDU, Daniel MILODIN, Cosmin LUGOJI 140
There is defined the concept of digital content. The requirements of an efficient management of the digital content are established. There are listed the quality characteristics of digital content. Orthogonality indicators of digital content are built up. They are meant to measure the image, the sound as well as the text orthogonality as well. Projects-base concept is introduced. There is presented the model of structuring the content in order to maximize orthogonality via a convergent iterative process. The model is instantiated for the digital content of a projects-base. It is introduced the application used to test the model. The paper ends with conclusions.
Keywords: digital, quality, orthogonality, projects-bases

Partially Supervised Approach in Signal Recognition
Catalina COCIANU, Luminita STATE, Doru CONSTANTIN, Corina SARARU 153
The paper focuses on the potential of principal directions based approaches in signal classification and recognition. In probabilistic models, the classes are represented in terms of multivariate density functions, and an object coming from a certain class is modeled as a random vector whose repartition has the density function corresponding to this class. In cases when there is no statistical information concerning the set of density functions corresponding to the classes involved in the recognition process, usually estimates based on the information extracted from available data are used instead. In the proposed methodology, the characteristics of a class are given by a set of eigen vectors of the sample covariance matrix. The overall dissimilarity of an object X with a given class C is computed as the disturbance of the structure of C, when X is allotted to C. A series of tests concerning the behavior of the proposed recognition algorithm are reported in the final section of the paper.
Keywords: signal processing, classification, pattern recognition, compression/decompression

Characteristics of the Audit Processes for Distributed Informatics Systems
Marius POPA, Cristian TOMA, Cristian AMANCEI 165
The paper contains issues regarding: main characteristics and examples of the distributed informatics systems and main difference categories among them, concepts, principles, techniques and fields for auditing the distributed informatics systems, concepts and classes of the standard term, characteristics of this one, examples of standards, guidelines, procedures and controls for auditing the distributed informatics systems. The distributed informatics systems are characterized by the following issues: development process, resources, implemented functionalities, architectures, system classes, particularities. The audit framework has two sides: the audit process and auditors. The audit process must be led in accordance with the standard specifications in the IT&C field. The auditors must meet the ethical principles and they must have a high-level of professional skills and competence in IT&C field.
Keywords: informatics audit, characteristic, distributed informatics system, standard.

Econometric Models Used in the Analysis of the Informal Economy at the Regional Level
Tudorel ANDREI, Bogdan OANCEA, Stelian STANCU, Andreea Iluzia IACOB 179
The disintegration of planned economies and the first elements of the market economy have resulted in a new attitude from some companies to transfer their activities to the informal economy. Assessing the probability that a company decides to conduct an economic activity can be done based on the application of the logit and probit econometric models. A series of data for different latent variables should be known for their implementation. This paper presents a number of problems related to the application of these models at the level of economic regions. Binary models are recommended because of a number of variables such as: the size of the informal economy at the level of a company, the size of unpaid taxes and duties due to their activities in the informal economy, which are not known in official statistics. These variables can be substituted to some extent by the latent variables for which data series are known.
Keywords: informal economy, econometric models, logit, probit

PhD Thesis Review: Software Metrics Refinement
Ion IVAN 189

Publishing guide for authors 192

Inforec Association 194