Salesian Journal on Information Systems

Number 14, 2014

3
A Distributed Quaternary Turbo Coded Cooperative Scheme

Authors: BALDINI FILHO, R.; , PENZE, S. Z.

Abstract

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Number of views: 401

Cooperative communications achieve MIMO-like diversity gains by introducing a relay that creates an independent faded path between the source and the destination. Coded cooperation integrates cooperation with channel coding in order to increase the bit error rate (BER) performance of cooperative communications. Turbo codewords can be built efficiently at the destination using encoded portions of the information sent by the source and the relay. This paper presents a distributed turbo cooperative coding scheme that utilizes convolutional codes defined over the finite ring of integers Z4 that performs better than its equivalent binary counterparts.

4
Análise do Livro "Linguagem, Prova e Lógica"

Authors: OLIVEIRA, M. V. M.

Abstract

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Number of views: 491

Neste artigo apresentamos um novo livro editado para a disciplina de Lógica. A abordagem e as várias aplicações oferecidas junto com o livro auxiliam no aprendizado e podem fazer com que os estudantes se motivem mais e tenham melhor aproveitamento nesta disciplina.

5
Teaching Programming

Authors: LINDEN, R.

Abstract

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Number of views: 479

This article discusses how university curricula could improve its performance in. terms of producing computer science graduates who are more attuned to the needs of the industry in which most of them will be employed. The evaluation systems that are currently in place in this country strengthen the tendency to regard teaching as a low priority activity completing a vicious circle of decline.

9
Trend Analysis of the Brazilian Scientific Production in Computer Science

Authors: TRUCOLO, C. C.; DIGIAMPETRI, L. A.

Abstract

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Number of views: 463

The growth of scientific information volume and diversity brings new challenges in order to understand the reasons, the process and the real essence that propel this growth. This information can be used as the basis for the development of strategies and public politics to improve the education and innovation services. Trend analysis is one of the steps in this way. In this work, trend analysis of Brazilian scientific production of graduate programs in the computer science area is made to identify the main subjects being studied by these programs in general and individual ways.

9
Digital and Collaborative Technologies for Smarter Distance Education

Authors: OLIVEIRA, E. A; AURELIANO, V. C. O. ; FRANÇA, R. S.; TEDESCO, P. C. A. R.

Abstract

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Number of views: 424

With the integration of web 2.0 and social technologies into educational practices, researchers have been faced with the challenge of providing better online virtual learning environments, that engage students in the learning processes. This challenge entails using the massive amounts of knowledge we generate in our digital footprints to provide personalized learning contents. In our research group, we have tried to tackle this challenge by answering two questions: (i) How to share, at the same time, the knowledge of a virtual course in a decentralized way in Social Networks, MOOC, VLE and others? (ii) How to provide pedagogical practices in virtual learning environments that allow students to build their knowledge in an autonomous and reflective way? In this article we present the work we have carried out to answer both questions.

10
Considering unstructured data for OLAP: a feasibility study using a systematic review

Authors: GONZÁLEZ, S. M.; BERBEL, T. R. L.

Abstract

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Number of views: 525

Among the technologies involved on Business Intelligence, Data Warehouse and OLAP have been widely used to identify, collect, process, integrate and analyze information for decision making, thus promoting business management. Data stored in a data warehouse used by conventional OLAP systems is structured in nature. However, data such as text documents, images and videos, characterized as semi or unstructured data, may also contain information of great value to business. In this context, we applied the systematic review methodology with the purpose of identifying, extracting and summarizing the main research results focused on the integration of unstructured data in data warehouse environments. We identified forty two studies which studies were classified in order to identify ongoing research subjects and potential gaps as future trends.

15
GAIA Service Catalog: A Framework for the Construction of IT Service Catalogs

Authors: TACONI, L. H.; BARROS, R. M.; ZARPELÃO B.B.

Abstract

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Number of views: 535

The high amount of IT services offered to organizations for boosting and maintaining their business goals makes it difficult to determine the quantity, description and the attributes of these services. This paper presents a framework to support the construction of IT Service Catalogs. The framework consists of a diagnostic assessment questionnaire, a maturity model and a set of services that guide the organization in the construction of an IT Service Catalog.

Number 13, 2014

6
Perspectives and Potential of the Brain-Computer Interface

Authors: MUSSATTO, G. G.; DE AVILA E SILVA, S.

Abstract

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Number of views: 411

A Brain-Computer Interface (BCI), also known as Brain-Machine Interface, is a system that allows for the interaction between the user and its surroundings using control signals generated by his brain activity. The improvement of the research on BCI correlates mainly with the advances of Neurophisiology and Computer Science. Initial research was dedicated to the development of devices for the communication of individuals who lost voluntary muscle control but had no cognitive impairment. Nowadays, we find applications in the fields of mobility, communication and the treatment of diseases of user who may or may not have movement impairment. Considering the expansion scenario of the BCI applications, this paper presents a pedagogical description of the recent publication on this field of study. Hence, we descrive the basic concepts related to this research area, as well as some of its applications and limitations.

9
Study of Cloud Based ERP Services for Small and Medium Enterprises (Data is Processed by Text Mining Technique)

Authors: SHARMA, R.; KESWANI, B.

Abstract

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Number of views: 531

The purpose of this research paper is to explore the knowledge of the existing studies related to cloud computing current trend. The outcome of research is demonstrated in the form of diagram which simplifies the ERP integration process for in-house and cloud eco-system. It will provide a conceptual view to the new client or entrepreneurs using ERP services and explain them how to deal with two stages of ERP systems (cloud and in-house). Also suggest how to improve knowledge about ERP services and implementation process for both stages. The work recommends which ERP services can be outsourced over the cloud. Cloud ERP is a mix of standard ERP services along with cloud flexibility and low cost to afford these services. This is a recent phenomenon in enterprise service offering. For most of non IT background entrepreneurs it is unclear and broad concept, since all the research work related to it are done in couple of years. Most of cloud ERP vendors describe their products as straight forward tasks. The process and selection of Cloud ERP Services and vendors is not clear. This research work draws a framework for selecting non-core business process from preferred ERP service partners. It also recommends which ERP services outsourced first over the cloud, and the security issues related to data or information moved out from company premises to the cloud eco-system.

9
Assessing the Stability and Robustness of Semantic Web Services Recommendation Algorithms Under Profile Injection Attacks

Authors: GRANDIN, P. H.; ADÁN-COELLO, J. M.

Abstract

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Number of views: 422

Recommendation systems based on collaborative filtering are open by nature, what makes them vulnerable to profile injection attacks that insert biased evaluations in the system database in order to manipulate recommendations. In this paper we evaluate the stability and robustness of collaborative filtering algorithms applied to semantic web services recommendation when submitted to random and segment profile injection attacks. We evaluated four algorithms: (1) IMEAN, that makes predictions using the average of the evaluations received by the target item; (2) UMEAN, that makes predictions using the average of the evaluation made by the target user; (3) an algorithm based on the k-nearest neighbor (k-NN) method and (4), an algorithm based on the k-means clustering method.The experiments showed that the UMEAN algorithm is not affected by the attacks and that IMEAN is the most vulnerable of all algorithms tested. Nevertheless, both UMEAN and IMEAN have little practical application due to the low precision of their predictions. Among the algorithms with intermediate tolerance to attacks but with good prediction performance, the algorithm based on k-nn proved to be more robust and stable than the algorithm based on k-means.

10
Contributions from the ludological analysis for the design of serious games

Authors: GOLDONI, D.; RIGO, S. J.; ALVES, I. M. R.

Abstract

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Number of views: 411

This article aims to describe contributions that the Ludological Analysis can offer to the development of serious games. We describe a case study evaluating the characteristics of different digital Serious Games for the understanding of the main elements that make players feel challenged and motivated. This study was conducted based on the application of concepts of Ludology, seeking to validate the factors associated with the liminality, a psychological state in which the player feels so engaged in the gaming experience that focuses, almost entirely, in the game. After identifying these factors in the games analyzed in the case study, these features are mapped to the needs and possibilities in the field of education, specifically in the analysis and planning of digital Serious Games, considering that it's observation may represent improvement in the conception and use of these materials.

11
Performance analysis of parallel modular multiplication algorithms for ECC in mobile devices

Authors: ARRUDA, T.V, VENTURINI, Y.R., SAKATA, T.C.

Abstract

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Number of views: 397

Modular multiplication is the main operation in Elliptic Curve Cryptography (ECC) on prime finite fields. It is executed most of the time and is costly because it requires a modular reduction and a multi-precision method. Therefore, its cost increases in proportion to the ECC's key size. It could be considered as a problem for mobile devices because, despite they have more resources nowadays, their performance is still limited. Moreover, processor devices' trends are multi-core, even in the case of mobile devices. All of these facts motivated us to investigate the performance of the parallel modular multiplication on a software level on a current mobile platform. Recent studies have shown that parallel modular multiplication is effective only with big key size, like ones required for RSA, but none of them have focused on mobile devices platform. In this article, we show that, even for a smaller key size, as required for ECC, the use of parallel modular multiplication guarantees a better performance on mobile devices.

21
Operation, Management, Security and Sustainability for Cloud Computing

Authors: WESTPHAL, C. B.; WESTPHAL C. M.; KOCH, F. L.; et al.

Abstract

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Number of views: 432

This paper presents some scope, context, proposals and solutions related with the following topics: Decision-Theoretic Planning for Cloud Computing; An Architecture for Risk Analysis in Cloud; Risk-based Dynamic Access Control for a Highly Scalable Cloud Federation; Challenges of Operationalizing PACS on Cloud Over Wireless Networks; Environment, Services and Network Management for Green Clouds; Provisioning and Resource Allocation for Green Clouds; and Optimizing Green Clouds through Legacy Network Infrastructure Management.