51,118 research outputs found
Hysteretic behavior of dissipative welded fuses for earthquake resistant composite steel and concrete frames
No full textChannel-embedded porous zirconia surfaces to mimic dentine-cementum functionality in dental Implants: Design, production and characterisation
No full textThis study introduces a novel concept of dental implant integration, fibrointegration, which aims to replicate the natural attachment mechanism of teeth. To achieve this, zirconia samples featuring internal channels and one to three external porous layers were developed using Computer-Aided Design/Manufacturing (CAD/CAM) and dipcoating techniques, with the aim of mimicking the functional properties of natural teeth and thereby promoting the fibrointegration of a zirconia root-analogue implant. Results showed that the channel-embedded porous surfaces exhibited enhanced porosity, increased surface roughness, and superhydrophilic behaviour. Furthermore, the presence of microchannels induced a strong capillary effect, facilitating immediate fluid rise and spreading. The coating thickness increased with the number of dips, with the double-layer porous coating achieving an optimal thickness (approximate to 100 mu m), resembling natural cementum and exhibiting superior scratch resistance. These findings highlight the potential of bioinspired, channel-embedded porous zirconia surfaces to promote cell adhesion, guide growth, and stimulate fibrointegration, thereby improving implant stability
Aspidodera vazi Proenca
No full textAspidodera vazi Proença Tolypeutes tricinctus (Linnaeus), unspecified site of infection, Piauí, NHR (CHIOC 4446 c).Published as part of Muniz-Pereira, Luís C., Vieira, Fabiano M. & Luque, José L., 2009, Checklist of helminth parasites of threatened vertebrate species from Brazil, pp. 1-45 in Zootaxa 2123 on page 10, DOI: 10.5281/zenodo.18817
Unsupervised online anomaly detection in Software Defined Network environments
No full textSoftware Defined Networking (SDN) simplifies network management and significantly reduces operational costs. SDN removes the control plane from forwarding devices (e.g., routers and switches) and centralizes this plane in a controller, enabling the management of the network forwarding decisions by programming the control plane with a high-level language. However, its centralized architecture may be compromised by flooding attacks, such as Distributed Denial of Service (DDoS) and portscan. Facing this challenge, we propose an Intrusion Detection System (IDS) based on online clustering to detect attacks in an evolving SDN network taking advantage of the entropy of source and destination IP addresses and ports. Our proposal is focused on avoiding the demand for labeling and previous knowledge to provide a practical and accurate method to address real-life online scenarios. Moreover, our proposal paves the way for a comprehensive analysis by projecting the cluster's structure over the feature space, providing insights on intensity, seasonality, and attack type. Our experiments were carried out with the DenStream algorithm in several databases attacked by DDoS and portscan with different intensities, durations, and overlapping patterns. When comparing DenStream performance to Half-Space-Trees, an accurate online one-class classification algorithm for anomaly detection, it was possible to expose the capacity of our unsupervised proposal, overcoming the one-class solution, and reaching f-measure rates above 99.60%
Artificial Immune Systems and Fuzzy Logic to Detect Flooding Attacks in Software-Defined Networks
No full textSoftware-defined Networking (SDN) has been discovered as an architecture that uses applications to make networks flexible and centrally controlled. Although SDN provides innovative management, it still susceptible to attacks daily. Traditional detection approaches may not be sufficient to contain these threats. In this paper, we present an Artificial Immune System based IDS named AIS-IDS, which is inspired by the human body's defense cells. AIS-IDS can detect variations in network behavior and identify attacks without prior knowledge about them. Along with AIS, the fuzzy logic is applied on detection to minimize the uncertainty when there is no clear boundary between anomalous and normal traffic behavior. We have simulated portscan and flooding attacks as well as used a public dataset with several types of DDoS attacks to assess our proposal. We compared the AIS-IDS performance with Naive Bayes, k-nearest neighbors, and the Local Outlier Factor. The AIS-IDS outperformed the compared algorithms, achieving f-measure rates 99.97% and 92.28% when submitted to a simulated and a public dataset, respectively
Seismic retrofit of a reinforced concrete school building using dissipative steel braces
No full textThe paper illustrates the seismic retrofit carried out on an existing school building located in
Italy by means of dissipating steel braces. The preliminary investigations, the design project, the
construction process and, eventually, the seismic response of the retrofitted building were presented. At
first, the manuscript reports the comprehensive study on the seismic vulnerability of the existing reinforced
concrete framed building. Many deficiencies consisting in improper detailing, poor quality of materials
and inadequate ductility were found. Furthermore, the torsional effects in this plan irregular building due
to the L-shape floor plans were evidenced. Then, the paper illustrates the displacement-based design
procedure of supplemental energy dissipation devices for seismic retrofit. Both buckling-restrained axial
dampers and steel hysteretic dampers were considered for seismic upgrading of the reinforced concrete
frame building. The effectiveness and reliability of the adopted seismic retrofitting technique and design
approach were finally investigated using comprehensive nonlinear static and dynamic analyses
Seismic assessment and base isolation retrofit of a modern heritage R/C swimming pool
No full textA modern heritage reinforced concrete (R/C) swimming pool building designed by Pier Luigi Nervi is examined in this paper. The distinguishing feature of the structure is represented by the barrel vault-shaped roof, constituted by prefab R/C curved beams with smoothed-V wavy section, typical of the internationally recognized Nervi’s style. The R/C columns and beams supporting the roof and the lateral aisles — originally designed for gravitational loads only and pursuing a minimal size philosophy with respect to the calculated stress states — have very small cross sections. As a consequence, the seismic performance assessment analysis carried out in this study shows general unsafe response conditions of these members. In order to substantially improve the seismic response capacity of the building, as well as to avoid any intrusive intervention on the exposed structural elements, an advanced retrofit strategy is proposed, which consists in the installation of a base isolation system incorporating double curved surface slider devices at the feet of all columns and below the pool tank
Differential Acquisition of m-Sequences using Recursive Soft Sequential Estimation
No full textIn this contribution a novel sequential estimation method is proposed for the acquisition of -sequences. This sequential estimation method exploits the principle of iterative soft-in-soft-out (SISO) decoding for enhancing the acquisition performance, and that of differential pre-processing for the sake of achieving an enhanced acquisition performance, when communicating over various communication environments. Hence the advocated acquisition arrangement is referred to as the Differential Recursive Soft Sequential Estimation (DRSSE) acquisition scheme. The DRSSE acquisition scheme exhibits a low complexity, which is similar to that of an -sequence generator, while achieving an acquisition time that is linearly dependent on the number of stages in the -sequence generator. A low acquisition time is achieved with the advent of the property that the proposed DRSSE scheme is capable of determining the real-time reliabilities associated with the decision concerning a set of, say , consecutive chips. This set of consecutive chips constitutes the sufficient initial condition for enabling the local -sequence generator to produce a synchronized local despreading -sequence replica. Owing to these attractive characteristics, the DRSSE acquisition scheme constitutes a promising initial synchronization scheme for acquisition of long -sequences, when communicating over various propagation environments
∑_(l+m=k,l,m≥0) ((α+l-1)¦l) ((β+m-1)¦m)=((α+β+k-1)¦k) and its application to negative binomial distribution
No full textWe prove here the following equation: ∑_(l+m=k,l,m≥0) ((α+l-1)¦l) ((β+m-1)¦m)=((α+β+k-1)¦k) and give its application to prove the reproductive property of the negative binomial distribution.
These finite sum equation involving binomial coefficients and proof of the reproductive property are not known as far as the author knows.論文(Article)departmental bulletin pape
De Maiestate / Praeside M. Jacobo Thomasio, Moralis Philosoph. P. P., publice disputabit Johannes Dunte, R. L. Author & Respon: ad diem 9. Septembr. H L. Q. C.
No full textDE MAIESTATE / PRAESIDE M. JACOBO THOMASIO, MORALIS PHILOSOPH. P. P., PUBLICE DISPUTABIT JOHANNES DUNTE, R. L. AUTHOR & RESPON: AD DIEM 9. SEPTEMBR. H L. Q. C.
De Maiestate / Praeside M. Jacobo Thomasio, Moralis Philosoph. P. P., publice disputabit Johannes Dunte, R. L. Author & Respon: ad diem 9. Septembr. H L. Q. C. (1)
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