Small excitonic complexes in a disk-shaped quantum dot

Confined excitonic complexes in two dimensions, consisting of N_e electrons and N_h holes, are studied by means of Bethe-Goldstone equations. Systems with up to twelve pairs, and asymmetric configurations with N_e \ne N_h are considered. The weak confinement regime gives indication of weak binding or even unbinding in the triexciton and the four-exciton system, and binding in the higher complexes.Comment: 13 pages, 4 figures, submitted to Physica

Purdue University Students\u27 Perceptions of Cybersecurity

An investigation into Purdue University students’ attitudes about cybersecurity was conducted. Students were asked about their thoughts on cybersecurity, cyber-terrorism, and how they protect themselves. The data indicated that students were both aware of cyber-threats and participated in potentially unsafe internet activities. A variety of misconceptions regarding online security exposed, highlighting the need for greater education for college students regarding staying safe during online activities

Artificial Intelligence in Cybersecurity

Keeping unsuitable web content from young eyes is a challenge, given the wide-open environment of the internet. Research was conducted into selecting an Artificial Intelligence interface to be used to train and select whether specific images represented explicit material or not. Ten potential vendors were reviewed, and Google Automl Cloud® was selected for training and verification testing. Unfortunately, it was difficult to obtain a sizable enough archive of approved images to complete the originally envisioned training and testing program. A modest-sized image data base was finally secured, and the code was successfully tested with a small data set, even though the results did not contain enough samples to establish the commercial-level reliability required for further testing

Innovation, R&D and Productivity in the Costa Rican ICT Sector: A Case Study

This paper addresses the relationships between innovation, research and development (R&D) and productivity in domestic ICT firms in Costa Rica. Factors considered were the types of innovation outputs produced by domestic ICT firms, the relative importance of innovation inputs, the impacts of innovation on firm productivity, the protection of innovations, and impediments to innovation. While most firms engaged in all types of output and input innovations, they appear to be driven by retaining or increasing market share rather than increasing productivity. Half of firms do not formally protect the intellectual property created by their innovations, are not familiar with methods for protecting innovation or the availability of government grants for such purposes, and face barriers associated with the Costa Rican Patent Office. Other impediments include lack of knowledge about financial resources available and scarcity of human resources. There is also evidence of knowledge spillovers through worker mobility from multinationals operating in Costa Rica to domestic ICT firms.Research and development, Information communications technology, Innovation, Costa Rica

An automatic procedure for the estimation of the tail index

Extreme Value Theory is increasingly used in the modelling of financial time series. The non-normality of stock returns leads to the search for alternative distributions that allows skewness and leptokurtic behavior. One of the most used distributions is the Pareto Distribution because it allows non-normal behaviour, which requires the estimation of a tail index. This paper provides a new method for estimating the tail index. We propose an automatic procedure based on the computation of successive normality tests over the whole of the distribution in order to estimate a Gaussian Distribution for the central returns and two Pareto distributions for the tails. We find that the method proposed is an automatic procedure that can be computed without need of an external agent to take the decision, so it is clearly objective.Tail Index; Hill estimator; Normality Test