51 resultados para Message Authentication Code
Resumo:
This paper investigates the profile of teachers in the island of Ireland who declared themselves willing to undertake professional development activities in programming, in particular to master programming by taking on-line courses involving the design of computer games. Using the Technology Acceptance Model (TAM), it compares scores for teachers “willing” to undertake the courses with scores for those who declined, and examines other differences between the groups of respondents. Findings reflect the perceived difficulties of programming and the current low status accorded to the subject in Ireland. The paper also reviews the use of games-based learning as a “hook” to engage learners in programming and discusses the role of gamification as a tool for motivating learners in an on-line course. The on-line course focusing on games design was met with enthusiasm, and there was general consensus that gamification was appropriate for motivating learners in structured courses such as those provided.
Resumo:
This paper investigated using lip movements as a behavioural biometric for person authentication. The system was trained, evaluated and tested using the XM2VTS dataset, following the Lausanne Protocol configuration II. Features were selected from the DCT coefficients of the greyscale lip image. This paper investigated the number of DCT coefficients selected, the selection process, and static and dynamic feature combinations. Using a Gaussian Mixture Model - Universal Background Model framework an Equal Error Rate of 2.20% was achieved during evaluation and on an unseen test set a False Acceptance Rate of 1.7% and False Rejection Rate of 3.0% was achieved. This compares favourably with face authentication results on the same dataset whilst not being susceptible to spoofing attacks.
Resumo:
Objective: Regular follow-up is essential to successful management of childhood cataract. We sought to assess whether a mobile phone short message service (SMS) for parents of children with cataract could improve follow-up adherence and the proportion of procedures performed in timely fashion. Design: Randomized, controlled trial. This trial is registered with ClinicalTrials.gov, NCT01417819. Participants: We included 258 parent-child pairs involved in the Childhood Cataract Program of the Chinese Ministry of Health. Methods: Participants were randomized (1:1) to a mobile phone SMS intervention or standard follow-up appointments. All participants were scheduled to attend <4 follow-up appointments according to the protocol. Parents in the intervention group received SMS automated reminders before scheduled appointments. The control group parents did not receive SMSs or any alternative reminder of scheduled appointments. Regular ocular examinations and analyses were performed by investigators masked to group allocation; however, study participants and the manager in charge of randomization and sending SMSs were not masked. Main Outcome Measures: Number of follow-up appointments attended, additional surgeries, laser treatments, changes in eyeglasses prescription, and occurrence of secondary ocular hypertension. Results: Among parent-child participants, 135 were randomly assigned to the SMS intervention and 123 to standard appointments. Attendance rates for the SMS group (first visit, 97.8%; second, 91.9%; third, 92.6%; fourth, 83%) were significantly higher than those for the control group (first visit, 87.8%; second, 69.9%; third, 56.9%; fourth, 33.3%). The increase in attendance rate for total number of follow-up visits with SMS reminders was 47.2% (relative risk [RR] for attendance, 1.47; 95% confidence interval [CI], 1.16-1.78; P = 0.003). The number needed to remind (NNR) to gain 1 additional visit by 1 child was 3 (95% CI, 1.8-4.2). A total of 247 clinical interventions were carried out in the SMS group and 134 in the control group (RR, 1.68; 95% CI, 1.37-1.99; P = 0.007). The NNR to result in 1 additional clinical intervention was 5 (95% CI, 3.5-6.5). Conclusions: The SMS reminders significantly improved follow-up adherence in pediatric cataract treatment. Using readily available mobile phone resources may be an effective and economic strategy to improve management of childhood cataract in China. Financial Disclosure(s): The authors have no proprietary or commercial interest in any of the materials discussed in this article. © 2012 American Academy of Ophthalmology.
Resumo:
Public health risk communication during emergencies should be rapid and accurate in order to allow the audience to take steps to prevent adverse outcomes. Delays to official communications may cause unnecessary anxiety due to uncertainty or inaccurate information circulating within the at-risk group. Modern electronic communications present opportunities for rapid, targeted public health risk communication. We present a case report of a cluster of invasive meningococcal disease in a primary school in which we used the school's mass short message service (SMS) text message system to inform parents and guardians of pupils about the incident, to tell them that chemoprophylaxis would be offered to all pupils and staff, and to advise them when to attend the school to obtain further information and antibiotics. Following notification to public health on a Saturday, an incident team met on Sunday, sent the SMS messages that afternoon, and administered chemoprophyaxis to 93% of 404 pupils on Monday. The use of mass SMS messages enabled rapid communication from an official source and greatly aided the public health response to the cluster.
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In order to protect user privacy on mobile devices, an event-driven implicit authentication scheme is proposed in this paper. Several methods of utilizing the scheme for recognizing legitimate user behavior are investigated. The investigated methods compute an aggregate score and a threshold in real-time to determine the trust level of the current user using real data derived from user interaction with the device. The proposed scheme is designed to: operate completely in the background, require minimal training period, enable high user recognition rate for implicit authentication, and prompt detection of abnormal activity that can be used to trigger explicitly authenticated access control. In this paper, we investigate threshold computation through standard deviation and EWMA (exponentially weighted moving average) based algorithms. The result of extensive experiments on user data collected over a period of several weeks from an Android phone indicates that our proposed approach is feasible and effective for lightweight real-time implicit authentication on mobile smartphones.
Resumo:
Real-space grids are a powerful alternative for the simulation of electronic systems. One of the main advantages of the approach is the flexibility and simplicity of working directly in real space where the different fields are discretized on a grid, combined with competitive numerical performance and great potential for parallelization. These properties constitute a great advantage at the time of implementing and testing new physical models. Based on our experience with the Octopus code, in this article we discuss how the real-space approach has allowed for the recent development of new ideas for the simulation of electronic systems. Among these applications are approaches to calculate response properties, modeling of photoemission, optimal control of quantum systems, simulation of plasmonic systems, and the exact solution of the Schrödinger equation for low-dimensionality systems.