An Ultracapacitor-Based No-Break System for Microcomputers

This work aims at presenting a no-break system for microcomputers using ultracapacitors in replacement of the conventional chemical batteries. We analyzed the most relevant data about average power consumption of microcomputers, electrical and mechanical characteristics of ultracapacitors and operation of no-break power circuits, to propose a configuration capable of working properly with a microcomputer switching mode power supply. Our solution was a sixteen-component ultracapacitor bank, with a total capacitance of 350 F and voltage of 10.8 V, adequate to integrate a low-capacity no-break system, capable of feeding a load of 180 Wh, during 75 s. Our proposed no-break increases the reliability of microcomputers by reducing the probability of user data losses, in case of a power grid failure, offering, so, a high benefit-cost ratio. The replacement of the battery by ultracapacitors allows a quick no-break recharge and low maintenance costs, since these modern components have a lifetime longer than the batteries. Moreover, this solution reduces the environmental impact and eliminates the constant recharge of the energy storage device.

On the Acoustic Filtering of the Pipe and Sensor in a Buried Plastic Water Pipe and its Effect on Leak Detection: An Experimental Investigation

Acoustic techniques have been used for many years to find and locate leaks in buried water distribution systems. Hydrophones and accelerometers are typically used as sensors. Although geophones could be used as well, they are not generally used for leak detection. A simple acoustic model of the pipe and the sensors has been proposed previously by some of the authors of this paper, and their model was used to explain some of the features observed in measurements. However, simultaneous measurements of a leak using all three sensor-types in controlled conditions for plastic pipes has not been reported to-date and hence they have not yet been compared directly. This paper fills that gap in knowledge. A set of measurements was made on a bespoke buried plastic water distribution pipe test rig to validate the previously reported analytical model. There is qualitative agreement between the experimental results and the model predictions in terms of the differing filtering properties of the pipe-sensor systems. A quality measure for the data is also presented, which is the ratio of the bandwidth over which the analysis is carried out divided by the centre frequency of this bandwidth. Based on this metric, the accelerometer was found to be the best sensor to use for the test rig described in this paper. However, for a system in which the distance between the sensors is large or the attenuation factor of the system is high, then it would be advantageous to use hydrophones, even though they are invasive sensors.

Serviço de Referência Virtual: implantação do serviço de chat

Introduction: With the invention of the Internet and the Collaborative Web, libraries had to rethink the way to offer their services. Thus, the U.S. libraries began a search for technological innovations in an effort to bring the library to the user through features that patrons commonly use. The Virtual Reference Service (VRS) through chat and reference services via videoconferencing are features that derived from this search. Objective: This article aims to outline the implementation process of Virtual Reference Services (SRV) libraries in American universities, particularly those for chat, as well as presenting the successful Brazilian experience. This paper also discusses factors to be considered for implementing virtual reference service via chat for libraries wishing to offer the service. Methodology: The research methodology is based on a theoretical search on international and national literature on the subject. The methodology also includes participant observation. Results: In Brazil the implementation of SRV in some university libraries has occurred and according to these institutions, the SRV is a service that benefits the community and puts the library in line with the demands of information technology and communication. Conclusions: It is concluded that online SRV is appropriate to the reality of university libraries in Brazil, since the institutions that offer the service have positive results from their assessments and believe they are adding value to their library.

Reliability of Web-Based Information in Inquiry Projects

This case study aims at identifying how a community of secondary school students selects web-based information and factors associated with the reliability of online reference sources during their collaborative inquiry (co-inquiry) projects. This study, conducted in a public secondary school in Brazil, focused on information literacy skills for collaborative open learning (colearning). The research is based on qualitative content analysis implemented on the online platform weSPOT. Although students are mindful of the importance of comparing different sources of information they seem not to be aware of reliability in online environments. Teacher's guidance is essential to support co-learners in developing competences, particularly related to critical thinking.

Sistema de recomendação de produtos online baseado em palavras-chave

This project aims to explore the many methods used for the development of recommendation systems to user ’ s items and apply the content - based recommendation method on a prototype system whose purpose is to recommend books to users. This paper exposes the most popular methods for creating systems capable of providing items (products) according to user preferences, such as collaborat ive filtering and content - based. It also point different techniques that can be applied to calculate the similarity between two entities, for items or users, as the Pearson ’s method, calculating the cosine of vectors and more recently, a proposal to use a Bayesian system under a Dirichlet distribution. In addition, this work has the purpose to go through various points on the design of an online application, or a website, dealing not only oriented algorithms issues, but also the definition of development to ols and techniques to improve the user’s experience. The tools used for the development of the page are listed, and a topic about web design is also discussed in order to emphasize the importance of the layout of the application. At the end, some examples of recommender systems are presented for curiosity , learning and research purposes

A new transmission model in cognitive radio based on cyclic generalized polynomial codes for bandwidth reduction

The frequency spectrums are inefficiently utilized and cognitive radio has been proposed for full utilization of these spectrums. The central idea of cognitive radio is to allow the secondary user to use the spectrum concurrently with the primary user with the compulsion of minimum interference. However, designing a model with minimum interference is a challenging task. In this paper, a transmission model based on cyclic generalized polynomial codes discussed in [2] and [15], is proposed for the improvement in utilization of spectrum. The proposed model assures a non interference data transmission of the primary and secondary users. Furthermore, analytical results are presented to show that the proposed model utilizes spectrum more efficiently as compared to traditional models.

Collaborative language learning in Teletandem: a resource for pre-service teacher education

This article presents some of the results of a qualitative research project about the influences of the pedagogic strategies used by a mediator (graduate student in applied linguistics) in the supervision process of a Teletandem partner (undergraduate student in languages) on her pedagogical practice. It was done within the project Teletandem Brazil: foreign language for all. Based on the reflective teaching paradigm and collaborative language learning, with special emphasis on tandem learning, we analyzed the contributions of the collaborative relationship established between the graduate student and the student-teacher in her first teaching experience. The results bring about implications for the field of language teacher education in a perspective of education within practice, evidencing the experience of collaborative learning in teletandem as an opportunity for reflective teacher education of pre-service teachers.

Ridge-based fingerprint matching using hough transform

Despite the efficacy of minutia-based fingerprint matching techniques for good-quality images captured by optical sensors, minutia-based techniques do not often perform so well on poor-quality images or fingerprint images captured by small solid-state sensors. Solid-state fingerprint sensors are being increasingly deployed in a wide range of applications for user authentication purposes. Therefore, it is necessary to develop new fingerprint-matching techniques that utilize other features to deal with fingerprint images captured by solid-state sensors. This paper presents a new fingerprint matching technique based on fingerprint ridge features. This technique was assessed on the MSU-VERIDICOM database, which consists of fingerprint impressions obtained from 160 users (4 impressions per finger) using a solid-state sensor. The combination of ridge-based matching scores computed by the proposed ridge-based technique with minutia-based matching scores leads to a reduction of the false non-match rate by approximately 1.7% at a false match rate of 0.1%. © 2005 IEEE.

ITScan: a web-based analysis tool for Internal Transcribed Spacer (ITS) sequences

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Recuperação de informação de música e dados ID3: possíveis aplicações

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Open innovation and user s involvement in new product development: a case study in the automotive sector

Innovation is an essential factor for obtaining competitive advantages. The search for external knowledge sources for product creation, which can contribute to the innovation process, has become a constant among companies, and users play an important role in this search. In this study, we aimed to analyze user’s involvement in the product development process based on open innovation concepts. We used the unique case study research method. This study was carried out in an automotive company that has developed a project of a concept car involving user’s through the Web 2.0. With such scope, the research demonstrates that users can contribute not only with generation of ideas but also with the innovation process itself.

Building Leadership: The Knowledge of Principals in Creating Collaborative Communities of Professional Learning

Research literature is replete with the importance of collaboration in schools, the lack of its implementation, the centrality of the role of the principal, and the existence of a gap between knowledge and practice--or a "Knowing-Doing Gap." In other words, there is a set of knowledge that principals must know in order to create a collaborative workplace environment for teachers. This study sought to describe what high school principals know about creating such a culture of collaboration. The researcher combed journal articles, studies and professional literature in order to identify what principals must know in order to create a culture of collaboration. The result was ten elements of principal knowledge: Staff involvement in important decisions, Charismatic leadership not being necessary for success, Effective elements of teacher teams, Administrator‘s modeling professional learning, The allocation of resources, Staff meetings focused on student learning, Elements of continuous improvement, and Principles of Adult Learning, Student Learning and Change. From these ten elements, the researcher developed a web-based survey intended to measure nine of those elements (Charismatic leadership was excluded). Principals of accredited high schools in the state of Nebraska were invited to participate in this survey, as high schools are well-known for the isolation that teachers experience--particularly as a result of departmentalization. The results indicate that principals have knowledge of eight of the nine measured elements. The one that they lacked an understanding of was Principles of Student Learning. Given these two findings of what principals do and do not know, the researcher recommends that professional organizations, intermediate service agencies and district-level support staff engage in systematic and systemic initiatives to increase the knowledge of principals in the element of lacking knowledge. Further, given that eight of the nine elements are understood by principals, it would be wise to examine reasons for the implementation gap (Knowing-Doing Gap) and how to overcome it.

Hierarchy-Based Access Control in Distributed Environments

Access control is a fundamental concern in any system that manages resources, e.g., operating systems, file systems, databases and communications systems. The problem we address is how to specify, enforce, and implement access control in distributed environments. This problem occurs in many applications such as management of distributed project resources, e-newspaper and payTV subscription services. Starting from an access relation between users and resources, we derive a user hierarchy, a resource hierarchy, and a unified hierarchy. The unified hierarchy is then used to specify the access relation in a way that is compact and that allows efficient queries. It is also used in cryptographic schemes that enforce the access relation. We introduce three specific cryptography based hierarchical schemes, which can effectively enforce and implement access control and are designed for distributed environments because they do not need the presence of a central authority (except perhaps for set- UP).

An Empirical Study of Fault Localization for End-User Programmers

End users develop more software than any other group of programmers, using software authoring devices such as e-mail filtering editors, by-demonstration macro builders, and spreadsheet environments. Despite this, there has been little research on finding ways to help these programmers with the dependability of their software. We have been addressing this problem in several ways, one of which includes supporting end-user debugging activities through fault localization techniques. This paper presents the results of an empirical study conducted in an end-user programming environment to examine the impact of two separate factors in fault localization techniques that affect technique effectiveness. Our results shed new insights into fault localization techniques for end-user programmers and the factors that affect them, with significant implications for the evaluation of those techniques.

Towards a Model of Information Systems User Competency

The ability to utilize information systems (IS) effectively is becoming a necessity for business professionals. However, individuals differ in their abilities to use IS effectively, with some achieving exceptional performance in IS use and others being unable to do so. Therefore, developing a set of skills and attributes to achieve IS user competency, or the ability to realize the fullest potential and the greatest performance from IS use, is important. Various constructs have been identified in the literature to describe IS users with regard to their intentions to use IS and their frequency of IS usage, but studies to describe the relevant characteristics associated with highly competent IS users, or those who have achieved IS user competency, are lacking. This research develops a model of IS user competency by using the Repertory Grid Technique to identify a broad set of characteristics of highly competent IS users. A qualitative analysis was carried out to identify categories and sub-categories of these characteristics. Then, based on the findings, a subset of the model of IS user competency focusing on the IS-specific factors – domain knowledge of and skills in IS, willingness to try and to explore IS, and perception of IS value – was developed and validated using the survey approach. The survey findings suggest that all three factors are relevant and important to IS user competency, with willingness to try and to explore IS being the most significant factor. This research generates a rich set of factors explaining IS user competency, such as perception of IS value. The results not only highlight characteristics that can be fostered in IS users to improve their performance with IS use, but also present research opportunities for IS training and potential hiring criteria for IS users in organizations.