A modified epidemiological model for computer viruses

Since the computer viruses pose a serious problem to individual and corporative computer systems, a lot of effort has been dedicated to study how to avoid their deleterious actions, trying to create anti-virus programs acting as vaccines in personal computers or in strategic network nodes. Another way to combat viruses propagation is to establish preventive policies based on the whole operation of a system that can be modeled with population models, similar to those that are used in epidemiological studies. Here, a modified version of the SIR (Susceptible-Infected-Removed) model is presented and how its parameters are related to network characteristics is explained. Then, disease-free and endemic equilibrium points are calculated, stability and bifurcation conditions are derived and some numerical simulations are shown. The relations among the model parameters in the several bifurcation conditions allow a network design minimizing viruses risks. (C) 2009 Elsevier Inc. All rights reserved.

Scheduler simulation using iSPD, an iconic-based computer grid simulator

Increased accessibility to high-performance computing resources has created a demand for user support through performance evaluation tools like the iSPD (iconic Simulator for Parallel and Distributed systems), a simulator based on iconic modelling for distributed environments such as computer grids. It was developed to make it easier for general users to create their grid models, including allocation and scheduling algorithms. This paper describes how schedulers are managed by iSPD and how users can easily adopt the scheduling policy that improves the system being simulated. A thorough description of iSPD is given, detailing its scheduler manager. Some comparisons between iSPD and Simgrid simulations, including runs of the simulated environment in a real cluster, are also presented. © 2012 IEEE.

The computer paradigm in vocational guidance

The technological advances in last decades have transformed the external resources of Vocational Counseling, Occupational Information and assessment of clients. Most computer systems follow a behaviorist-cognitive approach. However, the use of vocational counseling software is not exclusive to one conceptual approach. Computers are introduced in education from primary school; counselors and other educators are expected to use those systems. The attitude of counselors ranges from enthusiastic acceptance to complete refusal. Many counselors fear that computers will replace them. An underlying theory holds that counseling is based on the counselor-client interaction. A computer- client interaction cannot be considered vocational counseling. Counseling has five basic aims: prevention, assistance, education and development, service of diverse groups and research. The most relevant trends in computer-based counseling are: tests and questionnaires based on computers, adaptive development, computarized information, vocational counseling systems and research. Basic aims and the potential role of computers in achieving them are discussed. Present vocational counselors can use the technology of computers to link the past of our profession to its promising future. In view of these premises we have developed two computer systems that assist the vocational counseling process: "Professional Interests Questionnaire, Computer Version", and "Computer-based System of Vocational Counseling".

The computer paradigm in vocational guidance

The technological advances in last decades have transformed the external resources of Vocational Counseling, Occupational Information and assessment of clients. Most computer systems follow a behaviorist-cognitive approach. However, the use of vocational counseling software is not exclusive to one conceptual approach. Computers are introduced in education from primary school; counselors and other educators are expected to use those systems. The attitude of counselors ranges from enthusiastic acceptance to complete refusal. Many counselors fear that computers will replace them. An underlying theory holds that counseling is based on the counselor-client interaction. A computer- client interaction cannot be considered vocational counseling. Counseling has five basic aims: prevention, assistance, education and development, service of diverse groups and research. The most relevant trends in computer-based counseling are: tests and questionnaires based on computers, adaptive development, computarized information, vocational counseling systems and research. Basic aims and the potential role of computers in achieving them are discussed. Present vocational counselors can use the technology of computers to link the past of our profession to its promising future. In view of these premises we have developed two computer systems that assist the vocational counseling process: "Professional Interests Questionnaire, Computer Version", and "Computer-based System of Vocational Counseling".

The computer paradigm in vocational guidance

The technological advances in last decades have transformed the external resources of Vocational Counseling, Occupational Information and assessment of clients. Most computer systems follow a behaviorist-cognitive approach. However, the use of vocational counseling software is not exclusive to one conceptual approach. Computers are introduced in education from primary school; counselors and other educators are expected to use those systems. The attitude of counselors ranges from enthusiastic acceptance to complete refusal. Many counselors fear that computers will replace them. An underlying theory holds that counseling is based on the counselor-client interaction. A computer- client interaction cannot be considered vocational counseling. Counseling has five basic aims: prevention, assistance, education and development, service of diverse groups and research. The most relevant trends in computer-based counseling are: tests and questionnaires based on computers, adaptive development, computarized information, vocational counseling systems and research. Basic aims and the potential role of computers in achieving them are discussed. Present vocational counselors can use the technology of computers to link the past of our profession to its promising future. In view of these premises we have developed two computer systems that assist the vocational counseling process: "Professional Interests Questionnaire, Computer Version", and "Computer-based System of Vocational Counseling".

A Virtual Joystick as a Novel Interaction Modality for Surgeon-Computer Interaction During Computer-Assisted Surgical Procedures

Interacting with a computer system in the operating room (OR) can be a frustrating experience for a surgeon, who currently has to verbally delegate to an assistant every computer interaction task. This indirect mode of interaction is time consuming, error prone and can lead to poor usability of OR computer systems. This thesis describes the design and evaluation of a joystick-like device that allows direct surgeon control of the computer in the OR. The device was tested extensively in comparison to a mouse and delegated dictation with seven surgeons, eleven residents, and five graduate students. The device contains no electronic parts, is easy to use, is unobtrusive, has no physical connection to the computer and makes use of an existing tool in the OR. We performed a user study to determine its effectiveness in allowing a user to perform all the tasks they would be expected to perform on an OR computer system during a computer-assisted surgery. Dictation was found to be superior to the joystick in qualitative measures, but the joystick was preferred over dictation in user satisfaction responses. The mouse outperformed both joystick and dictation, but it is not a readily accepted modality in the OR.

Towartds Computer-aided Editing of Scientific and Technical Texts

The paper discusses facilities of computer systems for editing scientific and technical texts, which partially automate functions of human editor and thus help the writer to improve text quality. Two experimental systems LINAR and CONUT developed in 90s to control the quality of Russian scientific and technical texts are briefly described; and general principles for designing more powerful editing systems are pointed out. Features of an editing system being now under development are outlined, primarily the underlying linguistic knowledge base and procedures controlling the text.

Practical dynamic thermal management on Intel desktop computer

Fueled by increasing human appetite for high computing performance, semiconductor technology has now marched into the deep sub-micron era. As transistor size keeps shrinking, more and more transistors are integrated into a single chip. This has increased tremendously the power consumption and heat generation of IC chips. The rapidly growing heat dissipation greatly increases the packaging/cooling costs, and adversely affects the performance and reliability of a computing system. In addition, it also reduces the processor's life span and may even crash the entire computing system. Therefore, dynamic thermal management (DTM) is becoming a critical problem in modern computer system design. Extensive theoretical research has been conducted to study the DTM problem. However, most of them are based on theoretically idealized assumptions or simplified models. While these models and assumptions help to greatly simplify a complex problem and make it theoretically manageable, practical computer systems and applications must deal with many practical factors and details beyond these models or assumptions. The goal of our research was to develop a test platform that can be used to validate theoretical results on DTM under well-controlled conditions, to identify the limitations of existing theoretical results, and also to develop new and practical DTM techniques. This dissertation details the background and our research efforts in this endeavor. Specifically, in our research, we first developed a customized test platform based on an Intel desktop. We then tested a number of related theoretical works and examined their limitations under the practical hardware environment. With these limitations in mind, we developed a new reactive thermal management algorithm for single-core computing systems to optimize the throughput under a peak temperature constraint. We further extended our research to a multicore platform and developed an effective proactive DTM technique for throughput maximization on multicore processor based on task migration and dynamic voltage frequency scaling technique. The significance of our research lies in the fact that our research complements the current extensive theoretical research in dealing with increasingly critical thermal problems and enabling the continuous evolution of high performance computing systems.

A Virtual Joystick as a Novel Interaction Modality for Surgeon-Computer Interaction During Computer-Assisted Surgical Procedures

Interacting with a computer system in the operating room (OR) can be a frustrating experience for a surgeon, who currently has to verbally delegate to an assistant every computer interaction task. This indirect mode of interaction is time consuming, error prone and can lead to poor usability of OR computer systems. This thesis describes the design and evaluation of a joystick-like device that allows direct surgeon control of the computer in the OR. The device was tested extensively in comparison to a mouse and delegated dictation with seven surgeons, eleven residents, and five graduate students. The device contains no electronic parts, is easy to use, is unobtrusive, has no physical connection to the computer and makes use of an existing tool in the OR. We performed a user study to determine its effectiveness in allowing a user to perform all the tasks they would be expected to perform on an OR computer system during a computer-assisted surgery. Dictation was found to be superior to the joystick in qualitative measures, but the joystick was preferred over dictation in user satisfaction responses. The mouse outperformed both joystick and dictation, but it is not a readily accepted modality in the OR.

Dynamical models for computer viruses propagation

Nowadays, digital computer systems and networks are the main engineering tools, being used in planning, design, operation, and control of all sizes of building, transportation, machinery, business, and life maintaining devices. Consequently, computer viruses became one of the most important sources of uncertainty, contributing to decrease the reliability of vital activities. A lot of antivirus programs have been developed, but they are limited to detecting and removing infections, based on previous knowledge of the virus code. In spite of having good adaptation capability, these programs work just as vaccines against diseases and are not able to prevent new infections based on the network state. Here, a trial on modeling computer viruses propagation dynamics relates it to other notable events occurring in the network permitting to establish preventive policies in the network management. Data from three different viruses are collected in the Internet and two different identification techniques, autoregressive and Fourier analyses, are applied showing that it is possible to forecast the dynamics of a new virus propagation by using the data collected from other viruses that formerly infected the network. Copyright (c) 2008 J. R. C. Piqueira and F. B. Cesar. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Work domain analysis for training-system definition and acquisition

Training-needs analysis is critical for defining and procuring effective training systems. However, traditional approaches to training-needs analysis are not suitable for capturing the demands of highly automated and computerized work domains. In this article, we propose that work domain analysis can identify the functional structure of a work domain that must be captured in a training system, so that workers can be trained to deal with unpredictable contingencies that cannot be handled by computer systems. To illustrate this argument, we outline a work domain analysis of a fighter aircraft that defines its functional structure in terms of its training objectives, measures of performance, basic training functions, physical functionality, and physical context. The functional structure or training needs identified by work domain analysis can then be used as a basis for developing functional specifications for training systems, specifically its design objectives, data collection capabilities, scenario generation capabilities, physical functionality, and physical attributes. Finally, work domain analysis also provides a useful framework for evaluating whether a tendered solution fulfills the training needs of a work domain.

An adaptive educational system for higher education

The main objective of an Adaptive System is to adequate its relation with the user (content presentation, navigation, interface, etc.) according to a predefined but updatable model of the user that reflects his objectives, preferences, knowledge and competences [Brusilovsky, 2001], [De Bra, 2004]. For Educational Adaptive Systems, the emphasis is placed on the student knowledge in the domain application and learning style, to allow him to reach the learning objectives proposed for his training [Chepegin, 2004]. In Educational AHS, the User Model (UM), or Student Model, has increased relevance: when the student reaches the objectives of the course, the system must be able to readapt, for example, to his knowledge [Brusilovsky, 2001]. Learning Styles are understood as something that intent to define models of how given person learns. Generally it is understood that each person has a Learning Style different and preferred with the objective of achieving better results. Some case studies have proposed that teachers should assess the learning styles of their students and adapt their classroom and methods to best fit each student's learning style [Kolb, 2005], [Martins, 2008]. The learning process must take into consideration the individual cognitive and emotional parts of the student. In summary each Student is unique so the Student personal progress must be monitored and teaching shoul not be not generalized and repetitive [Jonassen, 1991], [Martins, 2008]. The aim of this paper is to present an Educational Adaptive Hypermedia Tool based on Progressive Assessment.

Sequencing educational resources with Seqins

Existing adaptive educational hypermedia systems have been using learning resources sequencing approaches in order to enrich the learning experience. In this context, educational resources, either expository or evaluative, play a central role. However, there is a lack of tools that support sequencing essentially due to the fact that existing specifications are complex. This paper presents Seqins as a sequencing tool of digital educational resources. Seqins includes a simple and flexible sequencing model that will foster heterogeneous students to learn at different rhythms. The tool communicates through the IMS Learning Tools Interoperability specification with a plethora of e-learning systems such as learning management systems, repositories, authoring and automatic evaluation systems. In order to validate Seqins we integrate it in an e-learning Ensemble framework instance for the computer programming learning domain.

Aquaponics System - An EPS@ISEP 2014 Spring Project

The goal of this project, one of the proposals of the EPS@ISEP 2014 Spring, was to develop an Aquaponics System. Over recent years Aquaponics systems have received increased attention due to its possibilities in helping reduce strain on resources within 1st and 3rd world countries. Aquaponics is the combination of Hydroponics and Aquaculture and mimics a natural environment in order to successfully apply and enhance the understanding of natural cycles within an indoor process. By using this knowledge of natural cycles it was possible to create a system with the capabilities similar to that of a natural environment with the benefits of electronic adaptions to enhance the overall efficiency of the system. The multinational team involved in its development was composed of five students, from five countries and fields of study. This paper covers their solution, involving overall design, the technology involved and the benefits it could bring to the current market. The team was able to achieve the final rendered Computer Aided Design (CAD) drawings, successfully performed all the electronic testing, and designed a solution under budget. Furthermore, the solution presented was deeply studied from the sustainability viewpoint and the team also developed a product specific marketing plan. Finally, the students involved in this project obtained new knowledge and skills.