Vibração de barras em pequena amplitude com efeito geométrico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evaluation of online tools as didactic resource in the university education

Recently, many efforts have been made in the academic world to adapt the new degrees to the new European Higher Education Area (EHEA). New technologies have been the most important factor to carry out this adaptation. In particular, the tools 2.0 have been spreading quickly, not just the Web 2.0, but even in all the educational levels. Nevertheless, it is now necessary to evaluate whether all these efforts and all the changes, carried out in order to obtain improved academic performance among students, have provided good results. Therefore, the aim of this paper is focused on studying the impact of the implementation of information and communication technologies (ICTs) in a subject belonging to a Master from the University of Alicante in the academic year (2010-2011). In special, it is an elective course called "Advanced Visual Ergonomics" from the Master of Clinical Optometry and Vision. The methodology used to teach this course differs from the traditional one in many respects. For example, one of the resources used for the development of this course is a blog developed specifically to coordinate a series of virtual works, whose purpose is that the student goes into specific aspects of the current topic. Next, the student participates in an active role by writing a personal assessment on the blog. However, in the course planning, there is an attendance to lessons, where the teacher presents certain issues in a more traditional way, that is, with a lecture supported with audiovisual materials, such as materials generated in powerpoint. To evaluate the quality of the results achieved with this methodology, in this work the personal assessment of the students, who have completed this course during this academic year, are collected. In particular, we want to know their opinion about the used resources, as well as the followed methodology. The tool used to collect this information was a questionnaire. This questionnaire evaluates different aspects of the course: a general opinion, quality of the received information, satisfaction about the followed methodology and the student´s critical awareness. The design of this questionnaire is very important to get conclusive information about the methodology followed in the course. The questionnaire has to have an adequate number of questions; whether it has many questions, it might be boring for the student who would pay no enough attention. The questions should be well-written, with a clear structure and message, to avoid confusion and an ambiguity. The questions should be objectives, without any suggestion for a desired answer. In addition, the questionnaire should be interesting to encourage the student´ s interest. In conclusion, this questionnaire developed for this subject provided good information to evaluate whether the methodology was a useful tool to teach "Advanced Visual Ergonomics". Furthermore, the student´s opinion collected by this questionnaire might be very helpful to improve this didactic resource.

Supporting pre-tender construction planning with virtual prototyping

Purpose – Virtual prototyping technologies linked to building information models are commonplace within the aeronautical and automotive industries. Their use within the construction industry is now emerging. The purpose of this paper is to show how these technologies have been adopted on the pre-tender planning for a typical construction project. Design/methodology/approach – The research methodology taken was an “action research” approach where the researchers and developers were actively involved in the production of the virtual prototypes on behalf of the contractor thereby gaining consistent access to the decisions of the planning staff. The experiences from the case study were considered together with similar research on other construction projects. Findings – The findings from the case studies identify the role of virtual prototyping in components modelling, site modelling, construction equipment modelling, temporary works modelling, construction method visualization and method verification processes. Originality/value – The paper presents a state-of-the-art review and discusses the implications for the tendering process as these technologies are adopted. The adoption of the technologies will lead to new protocols and changes in the procurement of buildings and infrastructure.

Integrating concrete and virtual materials in an elementary mathematics classroom : a case study of success with fractions

This paper describes an approach to introducing fraction concepts using generic software tools such as Microsoft Office's PowerPoint to create "virtual" materials for mathematics teaching and learning. This approach replicates existing concrete materials and integrates virtual materials with current non-computer methods of teaching primary students about fractions. The paper reports a case study of a 12-year-old student, Frank, who had an extremely limited understanding of fractions. Frank also lacked motivation for learning mathematics in general and interacted with his peers in a negative way during mathematics lessons. In just one classroom session involving the seamless integration of off-computer and on-computer activities, Frank acquired a basic understanding of simple common equivalent fractions. Further, he was observed as the session progressed to be an enthusiastic learner who offered to share his learning with his peers. The study's "virtual replication" approach for fractions involves the manipulation of concrete materials (folding paper regions) alongside the manipulation of their virtual equivalent (shading screen regions). As researchers have pointed out, the emergence of new technologies does not mean old technologies become redundant. Learning technologies have not replaced print and oral language or basic mathematical understanding. Instead, they are modifying, reshaping, and blending the ways in which humankind speaks, reads, writes, and works mathematically. Constructivist theories of learning and teaching argue that mathematics understanding is developed from concrete to pictorial to abstract and that, ultimately, mathematics learning and teaching is about refinement and expression of ideas and concepts. Therefore, by seamlessly integrating the use of concrete materials and virtual materials generated by computer software applications, an opportunity arises to enhance the teaching and learning value of both materials.

An optimising compiler for generated tiny virtual machines

VMSCRIPT is a scripting language designed to allow small programs to be compiled for a range of generated tiny virtual machines, suitable for sensor network devices. The VMSCRIPT compiler is an optimising compiler designed to allow quick re-targeting, based on a template, code rewriting model. A compiler backend can be specified at the same time as a virtual machine, with the compiler reading the specification and using it as a code generator.

Testing of a distributed generation system with a virtual grid

The paper proposes a solution for testing of a physical distributed generation system (DGs) along with a computer simulated network. The computer simulated network is referred as the virtual grid in this paper. Integration of DG with the virtual grid provides broad area of testing of power supplying capability and dynamic performance of a DG. It is shown that a DG can supply a part of load power while keeping Point of Common Coupling (PCC) voltage magnitude constant. To represent the actual load, a universal load along with power regenerative capability is designed with the help of voltage source converter (VSC) that mimics the load characteristic. The overall performance of the proposed scheme is verified using computer simulation studies.

A virtual test assessment tool for second year signal processing students

The development and use of a virtual assessment tool for a signal processing unit is described. It allows students to take a test from anywhere using a web browser to connect to the university server that hosts the test. While student responses are of the multiple choice type, they have to work out problems to arrive at the answer to be entered. CGI programming is used to verify student identification information and record their scores as well as provide immediate feedback after the test is complete. The tool has been used at QUT for the past 3 years and student feedback is discussed. The virtual assessment tool is an efficient alternative to marking written assignment reports that can often take more hours than actual lecture hall contact from a lecturer or tutor. It is especially attractive for very large classes that are now the norm at many universities in the first two years.

Multiuser virtual safety training system for tower crane dismantlement

Tower crane dismantling is one of the most dangerous activities in the construction industry. Tower crane erection and dismantlement causes 10–12% of the fatalities of all crane accidents. The nature of the task is such that off-the-job training is not practicable, and the knowledge and expertise needed has to be gained on the job. However, virtual trainers such as Microsoft Flight Simulator for airplane pilots and mission rehearsal exercise (MRE) for army personnel have been developed and are known to provide a highly successful means of overcoming the risks involved in such on-the-job learning and clearly have potential in construction situations. This paper describes the newly developed multiuser virtual safety training system (MVSTS) aimed at providing a similar learning environment for those involved in tower crane dismantlement. The proposed training system is developed by modifying an existing game engine. Within the close-to-reality virtual environment, trainees can participate in a virtual dismantling process. During the process, they learn the correct dismantling procedure and working location and to cooperate with other trainees by virtually dismantling the crane. The system allows the trainees to experience the complete procedure in a risk-free environment. A case study is provided to demonstrate how the system works and its practical application. The proposed system was evaluated by interviews with 30 construction experts with different backgrounds, divided into three groups according to their experience and trained by the traditional and virtual methods, respectively. The results indicate that the trainees of the proposed system generally learned better than those using the traditional method. The ratings also indicate that the system generally has great potential as a training platform.

Performance-driven live migration of multiple virtual machines in datacenters

Live migration of multiple Virtual Machines (VMs) has become an indispensible management activity in datacenters for application performance, load balancing, server consolidation. While state-of-the-art live VM migration strategies focus on the improvement of the migration performance of a single VM, little attention has been given to the case of multiple VMs migration. Moreover, existing works on live VM migration ignore the inter-VM dependencies, and underlying network topology and its bandwidth. Different sequences of migration and different allocations of bandwidth result in different total migration times and total migration downtimes. This paper concentrates on developing a multiple VMs migration scheduling algorithm such that the performance of migration is maximized. We evaluate our proposed algorithm through simulation. The simulation results show that our proposed algorithm can migrate multiple VMs on any datacenter with minimum total migration time and total migration downtime.

Semisupervised Dimensionality Reduction and Classification Through Virtual Label Regression

Semisupervised dimensionality reduction has been attracting much attention as it not only utilizes both labeled and unlabeled data simultaneously, but also works well in the situation of out-of-sample. This paper proposes an effective approach of semisupervised dimensionality reduction through label propagation and label regression. Different from previous efforts, the new approach propagates the label information from labeled to unlabeled data with a well-designed mechanism of random walks, in which outliers are effectively detected and the obtained virtual labels of unlabeled data can be well encoded in a weighted regression model. These virtual labels are thereafter regressed with a linear model to calculate the projection matrix for dimensionality reduction. By this means, when the manifold or the clustering assumption of data is satisfied, the labels of labeled data can be correctly propagated to the unlabeled data; and thus, the proposed approach utilizes the labeled and the unlabeled data more effectively than previous work. Experimental results are carried out upon several databases, and the advantage of the new approach is well demonstrated.

Virtual 3D (MUPAI Virtual 3D)

Virtual reality is currently considered a first-order resource for education and training. In this regard, artistic education, like other disciplines, is backing into this technology as a tool to overcome obstacles and contribute new ways of visualization and of providing information. And, in this case, the use of this technology presents enormous advantages for museums, especially, the more modest ones, which have few resources to disseminate and show their collections and works. Moreover, they have to resort to ingenious solutions to solve their difficulties. Therefore, the Pedagogic Museum of Children’s Art (MUPAI) backs into this technology to overcome some of the difficulties it encounters and to allow interested spectators to see its works, with great realism, and to visit its facilities anywhere in the world and at any time of the day. Hence, virtual reality unfolds new possibilities in the field of education that were inconceivable only a short time ago.

Evaluating relative impact of virtual reality system variables on architectural design comprehension and presence - A variable-centered approach using fractional factorial experiment

The relative contributions of five variables (Stereoscopy, screen size, field of view, level of realism and level of detail) of virtual reality systems on spatial comprehension and presence are evaluated here. Using a variable-centered approach instead of an object-centric view as its theoretical basis, the contributions of these five variables and their two-way interactions are estimated through a 25-1 fractional factorial experiment (screening design) of resolution V with 84 subjects. The experiment design, procedure, measures used, creation of scales and indices, results of statistical analysis, their meaning and agenda for future research are elaborated.

Virtual Office Hours Using Blackboard Collaborate

Virtual Office Hours are a possibility that any professor can take advantage of using Blackboard Collaborate. Why not cater to your online students by allowing them to have live chats with you as if you were face to face during regular office hours? Come learn about this innovative way to use Blackboard Collaborate with your students.