Connectivity properties of real BitTorrent swarms

( Ruben Cuevas ),( Michal Kryczka ),( Angel Cuevas ),( Carmen Guerrero ),( Arturo Azcorra ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.9

BitTorrent is one of the most important applications in the current Internet. Despite of its interest, we still have little knowledge regarding the connectivity properties of real BitTorrent swarms. In this paper we leverage a dataset including the connectivity information of 250 real torrents and more than 150k peers to carefully study the connectivity properties of peers. The main topology parameters of the studied swarms suggest that they are significantly less resilient than random graphs. The analysis of the peer level connectivity properties reveals that peers continuously change more than half of their neighbours. Furthermore, we also find that a leecher typically keeps stable connections with a handful of neighbours with which it exchanges most of its traffic whereas seeders do not establish long-term connections with any peer so that they can homogeneously distribute chunks among leechers. Finally, we have discovered that a significant portion of the studied peers (45%) have an important locality-biased neighbourhood composition.

ON g-CLOSED SETS AND g-CONTINUOUS MAPPINGS

Cueva, Miguel Caldas Department of Mathematics 1993 Kyungpook mathematical journal Vol.33 No.2

Usability and Evaluation of a Deployed 4G Network Prototype

Cuevas Antonio,Serrano Pablo,Moreno Jose I.,Bernardos Carlos J.,Jahnert Jurgen,Aguiar Rui L.,Marques Victor The Korea Institute of Information and Commucation 2005 Journal of communications and networks Vol.7 No.2

This article presents a field evaluation of an IP-based architecture for heterogeneous environments that has been developed under the aegis of the Moby Dick project, covering UMTS-like (universal mobile telecommunications system) TD-CDMA (time division-code division multiple access) wireless access technology, wireless and wired LANs. The architecture treats all transmission capabilities as basic physical and data-link layers, and replaces all higher-level tasks by IP-based strategies. The Moby Dick architecture incorporates mobile IPv6, fast handovers, AAA-control (authentication, authorisation, accounting), charging and quality of service (QoS) in an integrated framework. The architecture further allows for optimised control on the radio link layer resources. It has been implemented and tested by expert users, and evaluated by real users on field trials with multiple services available.

BCG and the risk of leprosy in Ciudad del Este, Paraguay, 2016-2017

Cuevas Nancy Carolina,Cardenas Victor M 한국역학회 2021 Epidemiology and Health Vol.43 No.-

OBJECTIVES: Paraguay has experienced a 35% reduction in the detected incidence of leprosy during the last ten years, as the vaccination coverage against tuberculosis (Bacillus of Calmette and Guerin [BCG] vaccine) reached ≥ 95% among infants. The objective of this case-control study was to evaluate the protective effect of BCG on the risk of leprosy. METHODS: We used a population-based case-control study of 20 leprosy confirmed cases reported among residents of Ciudad del Este, Paraguay, diagnosed in 2016-2017. Three controls were selected from a random sample of households from the city. We assessed vaccine effectiveness using 1- odds ratio [OR], and confounding for age, gender, education, occupation, and marital status using stratified and exact logistic regression, and explored if there was effect modification calculating the synergy factor (SF) and relative excess risk due to interaction (RERI). RESULTS: After controlling for age, gender, education, occupation and marital status, the OR of BCG scar on the risk of leprosy was 0.10 (95% confidence interval [CI], 0.02 to 0.45), for an estimate of vaccine effectiveness of 89.5% reduced risk of leprosy (95% CI, 55.2 to 98.1). There was evidence of heterogeneity by which the effectiveness of BCG seemed stronger among younger persons (Breslow-Day and Z-test of the SF had a p< 0.05), and both the RERI and SF indicated a less then multiplicative and additive interaction of BCG and younger age. CONCLUSIONS: BCG vaccination was associated with a decreased risk of leprosy in the study population, particularly in persons born after 1980.

Reply: A South Asian Perspective to ‘Myths and Misconceptions Around Antibiotic Resistance: Time to Get Rid of Them’

Amábile-Cuevas Carlos F. 대한감염학회 2023 Infection and Chemotherapy Vol.55 No.1

Usability and Evaluation of a Deployed 4G Network Prototype

A. Cuevas,P. Serrano,J. I. Moreno,C. J. Bernardos,J. Jahnert,R. L. Aguiar,V. Marques 한국통신학회 2005 Journal of communications and networks Vol.7 No.2

Myths and Misconceptions around Antibiotic Resistance: Time to Get Rid of Them

Amábile-Cuevas Carlos F. 대한감염학회 2022 Infection and Chemotherapy Vol.54 No.3

The antibiotic resistance arena is fraught with myths and misconceptions, leading to wrong strategies to combat it. It is crucial to identify them, discuss them in light of current evidence, and dispel those that are unequivocally wrong. This article proposes some concepts that may qualify as misconceptions around antibiotic resistance: the susceptible–resistant dichotomy; that incomplete antibiotic courses cause resistance; that resistance “emerges” in patients and hospitals; that antibiotics are mostly abused clinically; that resistance is higher in countries that use more antibiotics; that reducing antibiotic usage would reduce resistance; that financial incentives would “jumpstart” research and development of antibiotics; that generic and “original” antibiotics are the same; and that new anti-infective therapies are just around the corner. While some of these issues are still controversial, it is important to recognize their controversial status, instead of repeating them in specialized literature and lectures and, especially, in the planning of strategies to cope with resistance.

Anatomical variations of the equine popliteal tendon

Gabriel Cuevas-Ramos,Melanie Cova,David Arguelles,Marta Prades 대한수의학회 2019 Journal of Veterinary Science Vol.20 No.4

The function of the popliteal muscle and tendon in horses remains undescribed. In humans, it is considered a stabilizer of the posterior-lateral region of the knee; its function is closely related to that of the lateral collateral ligament (LCL) and meniscus. The popliteal tendon (PopT) constitutes the main proximal attachment of the popliteus muscle to the femur, and in humans, insertional variations have been described. Knowledge of anatomical variations is needed for the correct interpretation of diagnostic images and arthroscopic findings. To elucidate further the anatomy of the equine PopT, both hind limbs of 30 horses were dissected. Similar to humans, the equine PopT has 3 variants (types I, II, and III) depending on the number of components forming the tendon. Additionally, the area of insertion varies; the location can be either cranial, underneath, or caudal to the proximal insertion of the LCL. Furthermore, the PopT has a constant attachment to the lateral meniscus. The results of the present study are useful for clinicians working with equine orthopedics, as the tendon and insertional variants could affect the interpretation of diagnostic images and arthroscopic examinations.

Removal of iron from an electrolytic solution rich in copper using selective hydrometallurgy

( Ana Belen Cueva-sola ),( Jungshin Kang ),( Jin-young Lee ),( Rajesh Kumar Jyothi ) 한국폐기물자원순환학회 2022 ISSE 초록집 Vol.2022 No.-

Current technological development towards a cleaner, greener energy sources and an increased consumption of electronic and electric devices are driving the continuous increase in the demand of metals such as copper and iron. Even though, in the foreseeable future there is no predicted shortage of copper, it is imperative to improve and optimize the recovery of copper from secondary sources in pro of the environment protection and the achievement of circular economy. Currently, non-ferrous metals such as copper obtained from secondary sources are meeting the demand of around 30% of the worldwide requirement. However, copper usually comes associated with iron. By using hydrometallurgical processes, these metals are recovered and separated as a part of a continuous effort to reduce the environmental burden of wastewater and recover valuable metals from waste. During this experimental study, an electrolytic solution rich in Cu²⁺ (~ 50 g/L) with a small concentration of Fe²⁺ (~ 2 g/L) was processed using liquid- liquid extraction. Various phosphorous (P) based commercial extractants D2EHPA, Cyanex 272 and PC 88A were evaluated to remove iron. The optimum conditions for extraction and stripping were derived and removal of iron with minimal copper loss (< 3%) was proposed in a variety of hydrometallurgical routes.

Chemical, optical and transport characterization of ALD modified nanoporous alumina based structures

A.L. Cuevas,Ma. Valle Martínez de Yuso,L. Gelde,A.S. González,V. Vega,V.M. Prida,J. Benavente 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.91 No.-

Nanoporous alumina-based structures (NPA-bSs) obtained by anodization of aluminum in sulfuric acidmedium were coated by atomic layer deposition (ALD) of a thin conformal layer of different functionaloxides (Al2O3, TiO2, Fe2O3 or ZnO), leading to samples with similar geometrical parameters but differentsurface materials. Morphological characterization of the NPA-bSs confirms a reduction of about 35% inpore size associated to the presence of the oxides of interest, while chemical surface analysis permits theestimation of cover layer purity and thickness. Additionally, ALD functionalization also modifies optical(band-gap, refractive index and dielectric constant) according to transmittance and spectroscopicellipsometry results for visible and near-infrared regions, as well as electrolyte diffusive transportparameters (effectivefixed charge, ion transport numbers or ionic permselectivity) of the NPA-bSs, bothof which are dependent on the nature of the coating layer. Therefore, the suitability of ALD technique forgeometrical and functional modification of nanoporous structures is demonstrated, thus broadening thepotential application of these NPA-bSs platforms to optical sensing, nanophotonics, biosensing,microfluidics or drug delivery applications.