ECC programming in Java Card

9 páginas, 3 figuras, 3 listingElliptic Curve Cryptography (ECC) is a branch of public-key cryptography based on the arithmetic of el- liptic curves. Given its mathematical characteristics, ECC is currently one of the best options for protecting sensitive information. The lastest version of the Java Card platform includes several classes related to elliptic curves. However, potential developers are discouraged by the peculiarities of its programming model and the scarce information available. In this work, we present an up to date and extensive review of the ECC support in Java Card. In addition to that, we offer to the reader the complete code of two applications that will allow programmers to understand and test the entire application development process in Java Card.This work has been partially supported by Ministerio de Ciencia e Innovaci ́ on (Spain) under the grant TIN2011- 22668.Peer reviewe

Mercado laboral colombiano y baja cobertura pensional

Este trabajo examinará el problema que plantea la cobertura pensional de los colombianos menos educados y más vulnerables. Relaciona las tendencias del mercado laboral con la baja cobertura pensional: el sesgo del empleo urbano moderno contra los menos educados, ha generado para estos un ciclo de vida laboral muy marcado (empleo asalariado para los jóvenes, informal para los adultos): durante su fase asalariada temprana perciben ingresos relativamente mejores y, salvo en los períodos de desempleo, cotizan más al sistema pensional, durante su fase madura como informales perciben ingresos más bajos y dejan de cotizar. Ello, junto con la bajísima calidad del empleo rural, explica la baja cobertura pensional

A double pruning algorithm for classification ensembles

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-12127-2_11Proceedings of 9th International Workshop, MCS 2010, Cairo, Egypt, April 7-9, 2010.This article introduces a double pruning algorithm that can be used to reduce the storage requirements, speed-up the classification process and improve the performance of parallel ensembles. A key element in the design of the algorithm is the estimation of the class label that the ensemble assigns to a given test instance by polling only a fraction of its classifiers. Instead of applying this form of dynamical (instance-based) pruning to the original ensemble, we propose to apply it to a subset of classifiers selected using standard ensemble pruning techniques. The pruned subensemble is built by first modifying the order in which classifiers are aggregated in the ensemble and then selecting the first classifiers in the ordered sequence. Experiments in benchmark problems illustrate the improvements that can be obtained with this technique. Specifically, using a bagging ensemble of 101 CART trees as a starting point, only the 21 trees of the pruned ordered ensemble need to be stored in memory. Depending on the classification task, on average, only 5 to 12 of these 21 classifiers are queried to compute the predictions. The generalization performance achieved by this double pruning algorithm is similar to pruned ordered bagging and significantly better than standard bagging

Causas de lesión renal aguda en paciente con diagnóstico de hepatopatía crónica ingresados en el servicio de medicina interna del hospital Militar Alejandro Dávila Bolaños, periodo de enero 2017 a diciembre 2018

La cirrosis representa el estadio más avanzado de la enfermedad hepática crónica, ¿la lesión renal aguda representa una complicación común de la cirrosis hepática descompensada, con importantes implicaciones en la morbilidad y en la mortalidad. En este estudio describiremos las principales causas de lesión renal aguda en paciente con hepatopatía crónica, así como el pronóstico y días de estancia hospitalaria que genera este tipo de complicaciones Material y métodos: Tipo de estudio: Descriptivo, retrospectivo, de corte longitudinal. Área de trabajo: El presente estudio se realizó en el área de Hospitalización de medicina interna del Hospital Militar Escuela “Dr. Alejandro Dávila Bolaños” que está ubicado en la ciudad de Managua, en el periodo comprendido del 1 de enero del 2017 al 31 de diciembre del 2018. Universo: El presente estudio fue constituido 50 pacientes con diagnóstico de hepatopatía crónica con lesión renal aguda. Unidad de análisis: Expedientes de los(as) pacientes con diagnóstico de hepatopatía crónica con lesión renal aguda.Resultados: El sexo más afectado en el presente estudio fue el Masculino (70%), obteniéndose una razón de 4:1 Entre las complicaciones agudas que presentaban los pacientes con cirrosis hepática en este estudio lo más frecuente fue la encefalopatía Hepática dentro de la misma el grado I, en segundo lugar, Hemorragia digestiva alta y en tercero sepsis, secundario un 25% a peritonitis bacteriana espontanea, 35% síndromes diarreicos agudos, etiológicamente la causa principal de lesión renal aguda en este estudio fue de causa pre renal, dentro de lo principal Hemorragia digestiva alta segundo lugar, Perdidas gastrointestinales, lesión renal intrínseca con un 40% del total de pacientes Conclusiones: Etiológicamente la causa principal de lesión renal aguda en este estudio fue de causa pre renal, dentro de lo principal Hemorragia digestiva alta segundo lugar, Perdidas gastrointestinales, lesión renal intrínseca con un 40% del total de pacientes, así mismo de causa principal de sepsis, no cumpliendo criterios ninguno de los pacientes para síndrome hepatorrenal. Solo un 10% con lesión post renal de etiología por ureterolitiasi

A New Edit Distance for Fuzzy Hashing Applications

7 páginas, 5 tablas, 2 algoritmos. Comunicación presentada en: The 2015 World Congress in Computer Science, Computer Engineering, and Applied Computing (WORLDCOMP'15). The 2015 International Conference on Security and Management (SAM'15), Las Vegas, USA, July 27 - 30Similarity preserving hashing applications, also known as fuzzy hashing functions, help to analyse the content of digital devices by performing a resemblance comparison between different files. In practice, the similarity matching procedure is a two-step process, where first a signature associated to the files under comparison is generated, and then a comparison of the signatures themselves is performed. Even though ssdeep is the best-known application in this field, the edit distance algorithm that ssdeep uses for performing the signature comparison is not well-suited for certain scenarios. In this contribution we present a new edit distance algorithm that better reflects the similarity of two strings, and that can be used by fuzzy hashing applications in order to improve their results.This work has been partially supported by Comunidad de Madrid (Spain) under the project S2013/ICE-3095-CM (CIBERDINE) and by Ministerio de Economía y Com- petitividad (Spain) under the grant TIN2014-55325-C2-1-R (ProCriCiS).Peer reviewe

A Comparison of the Standardized Versions of ECIES

Elliptic Curve Cryptography (ECC) can be used as a tool for encrypting data, creating digital signatures or performing key exchanges. In relation to encryption, the Elliptic Curve Integrated Encryption Scheme (ECIES) is the best known scheme based on ECC, and as such it has been included in several cryptographic standards. In the present work, we provide an extensive review and comparison of the versions of ECIES included in documents from ANSI, IEEE, ISO/IEC, and SECG, highlighting the main differences between them that can prevent implementations of ECIES from being fully interoperable.This work has been partially supported by Ministerio de Ciencia e Innovación (Spain), under the grant TEC2009-13964-C04-02, and Ministerio de Industria, Turismo y Comercio (Spain), in collaboration with CDTI and Telefónica I+D, under the project Segur@ CENIT-2007 2004.Peer reviewe

Group signatures in practice

10 páginas, 2 figuras, 1 tabla. International Joint Conference. CISIS’15 and ICEUTE’15Group signature schemes allow a user to sign a message in an anonymous way on behalf of a group. In general, these schemes need the collaboration of a Key Generation Center or a Trusted Third Party, which can disclose the identity of the actual signer if necessary (for exam- ple, in order to settle a dispute). This paper presents the results obtained after implementing a group signature scheme using the Integer Factoriza- tion Problem and the Subgroup Discrete Logarithm Problem, which has allowed us to check the feasibility of the scheme when using big numbers.This work has been partially supported under the framework of the international cooperation program managed by National Research Foundation of Korea (NRF- 2013K2A1A2053670) and by Comunidad de Madrid (Spain) under the project S2013/ICE-3095-CM (CIBERDINE).Peer reviewe

Multiplicity of solutions in model‑based multi objective optimization of wastewater treatment plants

Wastewater treatment process design involves the optimization of multiple conflicting objectives. The detection of different equivalent solutions in terms of objective values is crucial for designers in order to efficiently switch to the new optimal operation policies if changes in the process conditions or new constraints occur. In this work, the dynamic multi-objective optimization of a municipal wastewater treatment plant model is carried out. The aim is to simultaneously optimize an economic cost term and an effluent quality index. The selected process variables for the optimization are (1) an aeration factor in the aerated tank previous to the clarifier, and (2) an internal recycle flow rate. Their time profiles are approximated using the control vector parameterization technique. To solve the multi-objective problem and find the Pareto front, the NSGA-II algorithm has been used. The simulation of different realistic scenarios which impose operational constraints (e.g., maintenance operations) reveals that, indeed, multiple solutions exist at least in some areas of the Pareto front. It is observed that different control profiles can produce nearly identical results in terms of Pareto solutions. The a priori knowledge of these equivalent solutions for different scenarios provides the decision makers with alternative choices to be adapted to their organizations policies when events altering decision variables bounds or adding new constraints to the process model occur.The authors are grateful to Ministry of Science, Innovation and Universities (MICINN) and FEDER for their fnancial support (Projects DPI2016-77538-R and RTI2018-099139-B-C21

Socio-economic factors do also matter: comments on the article "can climatic factors explain the differences in COVID-19 incidence and severity across the SPANISH regions?: an ecological study"

Phosri et al., commented on our previous study about the influence of climate variables at the beginning of the SARS-CoV-2 pandemic in Spain. They showed the impact of the association of gross domestic product (GDP) with the cumulative COVID-19 incidence per 105 inhabitants in our country and the rise of several methodologic issues. Here we discussed the main advantages and disadvantages of ecological studies and we advocate to test the hypothesis created in this type of studies using individual-level research designs

Can climatic factors explain the differences in COVID-19 incidence and severity across the Spanish regions?: An ecological study

Background: Environmental factors play a central role in seasonal epidemics. SARS-CoV-2 infection in Spain has shown a heterogeneous geographical pattern This study aimed to assess the influence of several climatic factors on the infectivity of SARS-CoV-2 and the severity of COVID-19 among the Spanish Autonomous Communities (AA.CC.). Methods: Data on coronavirus infectivity and severity of COVID-19 disease, as well as the climatic variables were obtained from official sources (Ministry of Health and Spanish Meteorological Agency, respectively). To assess the possible influence of climate on the development of the disease, data on ultraviolet radiation (UVR) were collected during the months before the start of the pandemic. To analyze its influence on the infectivity of SARS-CoV-2, data on UVR, temperature, and humidity were obtained from the months of highest contagiousness to the peak of the pandemic. Results: From October 2019 to January 2020, mean UVR was significantly related not only to SARS-CoV-2 infection (cumulative incidence -previous 14 days- × 105 habitants, rho = - 0.0,666; p = 0.009), but also with COVID-19 severity, assessed as hospital admissions (rho = - 0.626; p = 0.017) and ICU admissions (rho = - 0.565; p = 0.035). Besides, temperature (February: rho = - 0.832; p < 0.001 and March: rho = - 0.904; p < 0.001), was the main climatic factor responsible for the infectivity of the coronavirus and directly contributed to a different spread of SARS-CoV-2 across the Spanish regions. Conclusions: Climatic factors may partially explain the differences in COVID-19 incidence and severity across the different Spanish regions. The knowledge of these factors could help to develop preventive and public health actions against upcoming outbreaks of the disease