82 research outputs found
Construction of a polynomial invariant annihilation attack of degree 7 for T-310
Cryptographic attacks are typically constructed by black-box methods and combinations of simpler properties, for example in [Generalised] Linear Cryptanalysis. In this article, we work with a more recent white-box algebraic-constructive methodology. Polynomial invariant attacks on a block cipher are constructed explicitly through the study of the space of Boolean polynomials which does not have a unique factorisation and solving the so-called Fundamental Equation (FE). Some recent invariant attacks are quite symmetric and exhibit some sort of clear structure, or work only when the Boolean function is degenerate. As a proof of concept, we construct an attack where a highly irregular product of seven polynomials is an invariant for any number of rounds for T-310 under certain conditions on the long term key and for any key and any IV. A key feature of our attack is that it works for any Boolean function which satisfies a specific annihilation property. We evaluate very precisely the probability that our attack works when the Boolean function is chosen uniformly at random
Modelli empirico - meccanicistici e sistemi inferenziali adattivi neuro - fuzzy per la valutazione del decadimento dell’aderenza delle piste di volo aeroportuali
La ricerca è inquadrata nel settore scientifico disciplinare ICAR/04 “Strade, Ferrovie ed Aeroporti”, settore ERC principale PE - Physical Sciences and Engineering, sottosettori ERC 1. PE8_3 Civil engineering, architecture, maritime/hydraulic engineering, geotechnics, waste treatment; 3. PE8_8 Materials engineering (metals, ceramics, polymers, composites, etc.).
Uno dei temi più rilevanti della sicurezza in campo aeroportuale, è la pericolosità associata alle manovre "a terra" dei velivoli (decollo e atterraggio). In tale ambito, il rilievo dell’aderenza assume particolare importanza per il controllo ed il monitoraggio delle caratteristiche superficiali delle piste in uso per gli aeromobili. In particolare, l'azione frenante dei velivoli, in atterraggio o in decollo, è strettamente legata all’aderenza.
Dall’analisi delle serie storiche degli incidenti si evince che a fronte di tempi per le operazioni di decollo e atterraggio pari al 2% della durata dell’intera fase di volo si riscontra un tasso di incidenti mortali pari al 37%; di contro, alla fase di crociera che, temporalmente, rappresenta il 57% delle operazioni di volo, è associata una percentuale di incidenti mortali pari solo all’8%.
Le manovre “a terra” presentano tre criticità: 1) decelerazione dei velivoli in atterraggio o in decollo fallito; 2) controllo dell'assetto direzionale durante la corsa di decollo o di atterraggio; 3) innesco dello spin-up (rotazione) dei carrelli al touch down. In queste situazioni determinanti per il controllo dell'assetto direzionale, le forze aerodinamiche, innescandosi, possono ridurre l'azione frenante o generare momenti imbardanti. Le condizioni dello strato superficiale della pista influenzano l’entità delle sollecitazioni sugli aeromobili. Le azioni di frenatura in atterraggio o nella manovra di rinuncia al decollo possono essere compromesse da valori insufficienti del coefficiente di aderenza μ.
L'innesco della rotazione dei carrelli (spin-up) dopo la toccata (touch down) è fondamentale per il funzionamento corretto del sistema anti-skid. Ad esempio il controllo della traiettoria può essere invalidato se un carrello non raggiunge l'idoneo spin-up inibendo l'anti-skid. Anche l'azione sterzante del carrello anteriore (steering) può essere inficiata da scarsa aderenza della pista.
Il Dipartimento di Ingegneria Civile, Edile e Ambientale dell’Università degli Studi di Napoli Federico II conduce da anni, nell’ottica dello studio di base dei fenomeni nonché di un perfezionamento delle Normative di settore italiane, campagne di sperimentazione su aeroporti tra cui l’Aeroporto Internazionale Civile di Lamezia Terme. Le campagne sono rivolte al rilievo e monitoraggio del traffico aereo, delle caratteristiche geometriche infrastrutturali, delle caratteristiche tipologiche e fisico/meccaniche degli strati delle sovrastrutture, delle caratteristiche superficiali delle pavimentazioni, ed alla programmazione della manutenzione in particolare delle piste di volo.
L’analisi della bibliografia internazionale rivela l’interesse diffuso dei ricercatori nei confronti dei temi inerenti la gestione delle condizioni delle superfici delle piste. Numerosi sono in tal senso i temi da approfondire, e tra questi di particolare interesse è la perdita di aderenza della pista per gommatura da pneumatici.
Le raccomandazioni operative della Normativa di settore, quali ad esempio quelle contenute nella Circolare ENAC APT-10A del 30/10/2014, forniscono eccessiva discrezionalità al Gestore aeroportuale sulle procedure di rilievo ed elaborazione dati.
L’obiettivo principale della tesi di dottorato è l’analisi teorico-sperimentale del decadimento dell’aderenza di pavimentazioni per piste di volo, con particolare riferimento alla calibrazione di modelli rappresentativi del comportamento evolutivo dell’ aderenza in funzione dei carichi di traffico (fenomeno cumulativo).
La validazione delle variabili predittive dei modelli, la significatività dei dati di traffico, l’affidabilità e la sensitività delle misure di aderenza al variare delle caratteristiche prestazionali e di configurazione geometrica degli aeromobili, sono criteri indicatori utilizzati per la verifica dei risultati conseguiti.
Ulteriore misura della attendibilità dei risultati consisterà nell’implementazione dei modelli nei sistemi di gestione delle pavimentazioni delle piste aeroportuali.
I modelli elaborati infatti possono essere direttamente impiegati dagli operatori aeroportuali nella pratica tecnica per: predire il degrado dell’aderenza delle piste, con riferimento ai carichi effettivi degli aeromobili nel corso della vita utile degli strati superficiali della pavimentazione; e di conseguenza programmare le attività di manutenzione necessarie per garantire la sicurezza delle manovre a terra degli aeromobili
Effect of the microenvironment on osteoclast driven bone remodelling
Despite their rigid appearance, bones are dynamic organs going through continuous
remodelling cycles. The cells responsible for bone resorption are osteoclasts.
Activation of osteoclasts is regulated by hormones, cytokines, growth factors and
physical properties (such as oxygen tension and pH) of the bone microenvironment.
Alterations to the local microenvironment in which osteoclasts and their precursors
reside is of paramount importance for the control of their differentiation and activation
which can result in aberrant bone resorption. The focus of this project has been to gain
a better understating of how an altered microenvironment influences osteoclast
formation and activation.
To do so, a panel of feline and canine cancers cell lines as models of disrupted
microenvironment was studied. In particular, a novel bone invasive feline oral
squamous cell carcinoma (FOSCC) cell line was isolated (SMG), characterized and
its capacity to induce osteoclast formation and activity were investigated. Cats very
commonly present with FOSCC that invade the bone causing osteoclast activation and
bone resorption that worsen the tumour prognosis. However, how the cancer cells
modify their surrounding environment to activate osteoclasts is only partially
understood. An indirect co-culture system was designed to induce osteoclast
differentiation from feline bone marrow precursors in presence of conditioned media
from the cell lines. SMG conditioned media effect was compared with another FOSCC
conditioned media that was clinically non-bone invasive (SCCF1). Presence of either
conditioned media in the presence of CSF-1 and RANKL enhanced osteoclast
formation on plastic but only SMG conditioned media enhanced resorption on
mineralized plates. Moreover, the presence of SMG conditioned media enabled feline
bone marrow cells to survive in hypoxic conditions and differentiate into osteoclast.
Finally the effect of SMG conditioned media on a murine late osteoblast/early
osteocyte cell line (MLO-A5) was also examined. This effect was investigated as it is
possible that cancer cells induce osteoclast activation via other cells in the bone
microenvironment, such as osteoblasts and osteocytes. No significant effect of SMG
conditioned media on MLO-A5 cells transcription of relevant genes was detected.
A similar co-culture system was set up using canine bone marrow and initial studies
established a method for canine bone marrow osteoclast differentiation. Canine
osteosarcoma is common, especially in large breed dogs, and it causes local bone
resorption hence conditioned media from four osteosarcoma cell lines (KTOSA,
CSCOS, OSA-31 and D-17) were tested for their ability to alter osteoclast formation
and resorption activity. Only conditioned media from KTOSA was able to enhance
osteoclast formation on plastic.
The proteins present in canine and feline conditioned media from all cell lines
(representing the cell lines secretome) were analyzed by mass spectrometry and
proteins were identified that may be involved in osteoclast differentiation and
activation, such as AnnexinA2 and Insulin-like growth factor binding proteins.
In summary, in this study a method to study the influence of an altered
microenvironment on osteoclast differentiation and activation was established using
companion animal cancer cells. Moreover, analysis of the protein secreted by selected
cancer cell lines revealed potential therapeutic targets that might aid our
understanding of osteoclast activation and bone resorption in disease
LINEAR SCHEDULING ANALYSIS TOOLKIT FOR ROAD AND AIRPORTS CONSTRUCTION PROJECTS
The Linear Scheduling Method (LSM) is the most effective scheduling tool to use in linear projects. Computer programs have been developed for various scheduling techniques such as Bar Chart, PERT and CPM. There are not many commercially available toolkit for LSM and this lack of toolkit is one of the reasons for its limited usage. The product of this research is a toolkit comprised of models, procedures and tools that allow for implementation of the linear scheduling method. This toolkit is able to calculate the controlling activity path of such schedules, to level the resources of a project scheduled and to print reports of the status of the schedule. The paper describes the toolkit that was developed by the research, its documentation and example for an Italian case study that was scheduled using this prototype
CRASHES COMPARISON BEFORE AND AFTER SPEED CONTROL CAMERAS INSTALLATION: CASE STUDIES ON RURAL ROADS IN LITHUANIA AND ITALY
The study focused on the appraisal of the effectiveness of fixed speed control cameras regarding the reduction in crashes on the main study road in Lithuania. The task is to install the same technical reliable and validated solutions on homogeneous road sections in Italy that reflect the same geometric, traffic features as well as driver speed behaviour than those observed in Lithuania. The case studies were Via Baltica in Lithuania and S.P.430 in the Southern Italy. Three main roads belong to Via Baltica (A5, A8, A10) where a total of 191 crashes occurred during five years (2009−2013) of study with 276 injuries and 69 deaths. A total of five fixed speed cameras were placed on A5 road, two on A8 road and four on A10 road. After the installation of the speed control cameras, it was observed in two years a reduction in the number of crashes with deaths (51%) and injuries (27%) as well as a decrease in the crash rate values (19%). The case study in Italy was S.P.430 that consists of fourteen homogeneous road sections on basis of the curvature change rate evaluation and administrative government. A total of 138 crashes with 246 injuries and 20 deaths were recorded in 2009−2013 on a total length of 73 km almost. According to Italian methodology based on the calculation of crash rates for homogeneous road sections, the crash levels have been associated with each study road section. It was observed that 79% of the sections are characterized by a low crash level and the remaining 21% by a severe crash level. S.P.430 road sections with a severe crash level are potential locations with speed control cameras. As speed control cameras are missing in S.P. 430, there si no a remarkable reduction in the number of the crashes during the years as happened in Lithuania by similar infrastructural, land context, driver speed behaviour features between two cases study
Surface monitoring of road pavements using mobile crowdsensing technology
Pavement-surface characteristics should be considered during road maintenance for safe and comfortable driving. A detailed and up-to-date report of road-pavement network conditions is required to optimize a maintenance plan. However, manual road inspection methods, such as periodic visual surveys, are time-consuming and expensive. A common technology used to address this issue is SmartRoadSense, a collaborative system for the automatic detection of road-surface characteristics using Global Positioning System receivers and triaxial accelerometers contained in mobile devices. In this study, the results of the SmartRoadSense surveys conducted on Provincial Road 2 (SP2) in Salerno, Italy, were compared with the Distress Cadastre data for the same province and the pavement condition indices of different sections of the SP2. Although the effectiveness of the crowdsensing-based SmartRoadSense was found to vary with the distress type, the system was confirmed to be very efficient for monitoring the most critical road failures
RURAL ROAD REVERSE ENGINEERING USING BIM: AN ITALIAN CASE STUDY
The use of Building Information Modeling (BIM) is changing the way to perceive, manage and maintain any infrastructural project. The concept of Smart Roads relaunches the transport infrastructure sector through the digital transformation, able to create lean, quality, safer and cheaper infrastructures. The reverse engineering parametric modeling process was applied to “SS18 VAR” rural road, one of the main viabilities in Southern Italy. The case study was developed in according to the following steps: a) creating Digital Terrain Model (DTM); b) modeling horizontal alignment-vertical profiles; c) modeling 3D Corridor; d) modeling Viaducts; e) creating realistic 3D rendering. Bentley Systems software® were used in this study. The case study provided interesting elements to evaluate the advantages and disadvantages of design practice through BIM style tools, as well as the current state of the methodology itsel
Preliminary Study on Runway Pavement Friction Decay Using Data Mining
AbstractSurfaces of airport pavements are subject to the friction decay phenomenon. A recurrent problem for the runways is represented by the deposits of vulcanized rubber of aircraft tires. This happens mainly in the touch-down areas during landing operations, and the loss of grip compromises the safety of both take-off and landing operations. This study moves from the International Civil Aviation Organization and the Italian Civil Aviation Authority provisions concerning runway friction measurement and reporting to a better way to analyze friction data. Being data mining the computational process of discovering patterns in a large data sets, data mining techniques are very helpful to reach this target. Unsupervised and supervised classification methods to analyze friction data detected by Grip Tester Trailer were employed. First, K-means and Subtractive Clustering were applied to divide data into a certain number of clusters representing the different areas of consumption. In a second time two different Classification and Regression Trees models, CART and GCHAID, were employed to split the data points of the runway into nodes. At the end of the process scatterplots were built and better visualized through non-linear regressions. The decay curves obtained were of service to compare the results achieved using data mining techniques versus the International Civil Aviation Organization and the Italian Civil Aviation Authority provisions in order to find out the best way to analyze friction data. The final goals are to assure an optimum scheduling of the Airport Pavement Management System, as well as users safety
Verifying the Mechanical Performance of Cold and Hot Asphalt Mastics Containing Jet Grouting Waste as a Filler
In the road construction sector, the CO2 emissions that affect global warming are, in most cases, from the asphalt mixtures production activities that are carried out at high temperature (above 160 °C). The research here presented aims to investigate the physical-mechanical properties of asphalt mastics made up using jet grouting waste (JW) as a filler produced through both cold (40–50 °C) and hot mixing process. The first step focused primarily on examining the effects of optimal blending time and curing time of the mastics. The second step focused on the investigation of the rheological properties using a dynamic shear rheometer and carrying out a frequency sweep test at temperatures ranging from 0 to 50 °C with increments of 10 °C, and a multiple stress creep and recovery (MSCR) test under 0.1 and 3.2 kPa load levels at temperatures of 40 and 50 °C. Four cold asphalt mastic solutions were analyzed and then compared to three hot traditional ones, keeping constant, on the one hand, the binder weight and filler over binder weight ratio (0.5), and, on the other hand, changing the type and amount of filler. The compositions of the hot and cold asphalt mastics were as follows: (a) 33% limestone filler (LF) plus 67% bitumen (concerning the cold mixing process, the bitumen content refers to the amount of bitumen into the bitumen emulsion), (b) 33% JW plus 67% bitumen, (c) 16.5% LF plus 16.5% JW and 67% bitumen. The fourth solution designed only for cold asphalt mastic was made up of 33% Portland cement (PC) plus 67% bitumen (referring to the amount of bitumen in the bitumen emulsion). The main findings showed that the optimal performance was achieved at high test temperature by cold and hot asphalt mastics made up adding LF and JW filler, which showed a pronounced elastic behavior. Moreover, the cold asphalt mastic solution made up of LF and JW filler showed better performance than the mastic made up using PC, reaching over 40% increase of the shear modulus and 30% lower non-recoverable creep compliance values at all test temperatures
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