Generative Adversarial Networks for Bitcoin Data Augmentation

In Bitcoin entity classification, results are strongly conditioned by the ground-truth dataset, especially when applying supervised machine learning approaches. However, these ground-truth datasets are frequently affected by significant class imbalance as generally they contain much more information regarding legal services (Exchange, Gambling), than regarding services that may be related to illicit activities (Mixer, Service). Class imbalance increases the complexity of applying machine learning techniques and reduces the quality of classification results, especially for underrepresented, but critical classes. In this paper, we propose to address this problem by using Generative Adversarial Networks (GANs) for Bitcoin data augmentation as GANs recently have shown promising results in the domain of image classification. However, there is no "one-fits-all" GAN solution that works for every scenario. In fact, setting GAN training parameters is non-trivial and heavily affects the quality of the generated synthetic data. We therefore evaluate how GAN parameters such as the optimization function, the size of the dataset and the chosen batch size affect GAN implementation for one underrepresented entity class (Mining Pool) and demonstrate how a "good" GAN configuration can be obtained that achieves high similarity between synthetically generated and real Bitcoin address data. To the best of our knowledge, this is the first study presenting GANs as a valid tool for generating synthetic address data for data augmentation in Bitcoin entity classification.Comment: 8 pages, 5 figures, 4 table

The Enduring Value of Research in Medical Education

Evidence-based medicine (EBM) relies on scientific data to guide diagnosis and treatment and is recognized as the current paradigm in medicine. Accordingly, every current and future physician should be knowledgeable about its principles and methodologies. Embracing research and EBM is essential to modern clinical practice; however, trainees and physicians still struggle with the value of research-related courses and knowledge on epidemiology and research methodology is often poor. In this article we provide a cogent discussion of the importance of research as an indispensable discipline in medical education through a detailed analysis of the literature. We review the evolution of medicine towards EBM and discuss the myriad of benefits that research has on medical careers, leadership roles, mentoring relationships, social networking, and personal growth and development. Participation in research contributes to medicine, public health, and society while simultaneously allowing the achievement of a high level of personal satisfactio

Cascading Machine Learning to Attack Bitcoin Anonymity

Bitcoin is a decentralized, pseudonymous cryptocurrency that is one of the most used digital assets to date. Its unregulated nature and inherent anonymity of users have led to a dramatic increase in its use for illicit activities. This calls for the development of novel methods capable of characterizing different entities in the Bitcoin network. In this paper, a method to attack Bitcoin anonymity is presented, leveraging a novel cascading machine learning approach that requires only a few features directly extracted from Bitcoin blockchain data. Cascading, used to enrich entities information with data from previous classifications, led to considerably improved multi-class classification performance with excellent values of Precision close to 1.0 for each considered class. Final models were implemented and compared using different machine learning models and showed significantly higher accuracy compared to their baseline implementation. Our approach can contribute to the development of effective tools for Bitcoin entity characterization, which may assist in uncovering illegal activities.Comment: 15 pages,7 figures, 4 tables, presented in 2019 IEEE International Conference on Blockchain (Blockchain

Optimized Parameter Search Approach for Weight Modification Attack Targeting Deep Learning Models

Deep neural network models have been developed in different fields, bringing many advances in several tasks. However, they have also started to be incorporated into tasks with critical risks. That worries researchers who have been interested in studying possible attacks on these models, discovering a long list of threats from which every model should be defended. The weight modification attack is presented and discussed among researchers, who have presented several versions and analyses about such a threat. It focuses on detecting multiple vulnerable weights to modify, misclassifying the desired input data. Therefore, analysis of the different approaches to this attack helps understand how to defend against such a vulnerability. This work presents a new version of the weight modification attack. Our approach is based on three processes: input data clusterization, weight selection, and modification of the weights. Data clusterization allows a directed attack to a selected class. Weight selection uses the gradient given by the input data to identify the most-vulnerable parameters. The modifications are incorporated in each step via limited noise. Finally, this paper shows how this new version of fault injection attack is capable of misclassifying the desired cluster completely, converting the 100% accuracy of the targeted cluster to 0–2.7% accuracy, while the rest of the data continues being well-classified. Therefore, it demonstrates that this attack is a real threat to neural networks.This research has been partially funded by European Union’s Horizon 2020 research and innovation programme project SPARTA and by the Basque Government under ELKARTEK project (LANTEGI4.0 KK-2020/00072)

Susceptibility of different life stages of Blattella germanica (Blattodea: Blattellidae) and Periplaneta fuliginosa (Blattodea: Blattidae) to entomopathogenic fungi

The susceptibility of nymphs and adults of the German cockroach, Blattella germanica Linnaeus (Blattodea: Blattellidae) and the smokybrown cockroach, Periplaneta fuliginosa Serville (Blattodea: Blattidae) to Argentinian isolates of the entomopathogenic fungi Metarhizium anisopliae (Metschn.) Sorokin (CEP 085) and Beauveria bassiana (Bals.-Criv.) Vuill. (CEP 077) was evaluated. Fungi were tested by using two different methods: bait and direct contact. Mortality was monitored daily for twenty days to obtain LT50. M. anisopliae produced 60 and 93% mortality in nymphs and adults of B. germanica, respectively, when conidia were applied by direct contact. The LT50 for adults was 3.8 days, and 8.6 days for nymphs. Direct contact of B. bassiana produced 80% mortality on adults of B. germanica with a LT50 of 4.9 days, and for nymphs 40 % mortality in 10 days. When B. germanica was exposed to bait, the level of mortality was significant in adults. Nymphs of P. fuliginosa were treated with bait with M. anisopliae and B. bassiana and they caused 50% mortality with a LT50 of 22 days, and LT50 of 27 days respectively. Nymphs and adults of P. fuliginosa treated by direct contact and adults treated with bait showed that mortality level was not significantly different as compared to the control. Results showed differences in susceptibility between the two species of cockroaches and between nymphs and adults of the same species. In addition, different responses to the fungal species with the two methods that were used in the bioassays have been demonstrated. This is the first report of susceptibility of P. fuliginosa to entomopathogenic fungi. This study demonstrates the potential of fungi as biocontrol agents against this pest.Fil: Gutierrez, Alejandra Concepción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentina. Universidad Nacional de La Plata; ArgentinaFil: García, Juan José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentina. Universidad Nacional de La Plata; ArgentinaFil: Alzogaray, Raul Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación de Plagas e Insecticidas; ArgentinaFil: Urrutia, María I.. Universidad Nacional de La Plata; ArgentinaFil: Lopez Lastra, Claudia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentina. Universidad Nacional de La Plata; Argentin

Desarrollo de los equipos de prueba para la implementación de ensayos de resistencia a factores físicos aplicados a vidrios de seguridad según las normas NTE INEN 1722, 1724, 1726 y 1731.

Se ha desarrollado un sistema compuesto de varios ensayos de resistencia a factores físicos ambientales y visuales según los requerimientos de las normas NTE INEN 1669, 1722, 1724, 1726 y 1731 con la finalidad de verificar los requerimientos mínimos que deben cumplir los vidrios de seguridad laminados y templados (parabrisas, lunetas, ventanas laterales, etc.) para ser instalados en automotores de transporte de pasajeros o carga que se fabriquen en el país. Los factores físicos a ensayar son: fragmentación, impacto, alta temperatura y humedad, los que se describen a continuación: para el ensayo de fragmentación constan de un martillo, mesa, balanza, el cual consiste en romper las muestras, contar y pesar los fragmentos más grandes. El ensayo de impacto (maniquí) consta de una torre telescópica, maniquí y porta muestras, este a su vez consiste en elevar 1,5 m el maniquí y dejar caer sin impulso. El ensayo de alta temperatura consta de un recipiente, termómetro, agitador, consiste en mantener las pobretas sumergidas durante 2 horas en agua a ebullición. El ensayo de humedad consta de un recipiente, resistencias eléctricas, agitador, consiste en sumergir en agua las probetas durante 2 semanas manteniendo la temperatura del agua entre 49 y 54 o C. Las pruebas realizadas resultaron aceptables, confirmando la calidad de producto para aquellos que tienen sello INEN y la no conformidad de aquellos que no cuentan con este requisito. Finalmente se elaboró un sistema documental de acuerdo a los requerimientos establecidos en las normas para facilitar la ejecución y registro de ensayos.It has developed a system composed of several tests of resistance to environmental and visual physical factors according to the requirements of the NTE INEN 1669, 1722, 1724, 1726, and 1731 standards in order to verify the minimum requirements to be met laminated safety glasses and temperature (windshield, rear windows, side windows, etc.) to be installed in motor passenger or cargo being manufactured in the country. Physical factors to be tested are: fragmentation, impact, high temperature and humidity, which are described below for the fragmentation test consists of a hammer, table, balance, which is the break the samples, counting and weighing fragments bigger. The impact test (dummy) consists of a telescopic tower, dummy and sample holder, this in turn is to raise 1.5 m drop the dummy and without momentum. The high temperature test consists of a container, thermometer, stirrer, it is to maintain the specimens immersed for 2 hours in boiling water. The humidity test consists of a container, electrical resistors stirrer is immersed in water for 2 weeks specimens maintaining the water temperature between 49 and 54 ºC. The tests were acceptable, confirming product quality seal for those who have INEN and the nonconformity of those who do not have this requirement. Finally a documentary system according to the requirements established in the rules to facilitate the implementation and trials register was developed

Susceptibility of different life stages of <i>Blattella germanica</i> (Blattodea: Blattellidae) and <i>Periplaneta fuliginosa</i> (Blattodea: Blattidae) to entomopathogenic fungi

The susceptibility of nymphs and adults of the German cockroach, Blattella germanica Linnaeus (Blattodea: Blattellidae) and the smokybrown cockroach, Periplaneta fuliginosa Serville (Blattodea: Blattidae) to Argentinian isolates of the entomopathogenic fungi Metarhizium anisopliae (Metschn.) Sorokin (CEP 085) and Beauveria bassiana (Bals.-Criv.) Vuill. (CEP 077) was evaluated. Fungi were tested by using two different methods: bait and direct contact. Mortality was monitored daily for twenty days to obtain LT50. M. anisopliae produced 60 and 93% mortality in nymphs and adults of B. germanica, respectively, when conidia were applied by direct contact. The LT50 for adults was 3.8 days, and 8.6 days for nymphs. Direct contact of B. bassiana produced 80% mortality on adults of B. germanica with a LT50 of 4.9 days, and for nymphs 40 % mortality in 10 days. When B. germanica was exposed to bait, the level of mortality was significant in adults. Nymphs of P. fuliginosa were treated with bait with M. anisopliae and B. bassiana and they caused 50% mortality with a LT50 of 22 days, and LT50 of 27 days respectively. Nymphs and adults of P. fuliginosa treated by direct contact and adults treated with bait showed that mortality level was not significantly different as compared to the control. Results showed differences in susceptibility between the two species of cockroaches and between nymphs and adults of the same species. In addition, different responses to the fungal species with the two methods that were used in the bioassays have been demonstrated. This is the first report of susceptibility of P. fuliginosa to entomopathogenic fungi. This study demonstrates the potential of fungi as biocontrol agents against this pest.Centro de Estudios Parasitológicos y de Vectore