867 resultados para Intrusion Detection System (IDS)
Resumo:
Iowa has approximately 1000 bridges that have been overlaid with a nominal 2" of portland cement concrete. A Delamtect survey of a sampling of the older overlaid bridges indicated delaminations in several of them. Eventually these bridges as well as those that have not received an overlay must be programmed for rehabilitation. Prior to rehabilitation the areas which are delaminated must be identified. There are currently two standard methods of determining delaminated areas in bridge decks; sounding with a metal object or a chain drag and sounding with an electro-mechanical sounding system (Delamtect). Sounding with a metal object or chain drag is time consuming and the accuracy is dependent on the ear of the operator and may be affected by traffic noise. The Delamtect requires less field time but the graphical traces require that data reduction be done in the office. A recently developed method of detecting delamination is infrared thermography. This method is based on the temperature difference between sound and delaminated concrete. A contract was negotiated with Donohue and Associates, Inc. of Sheboygan, Wisconsin, to survey 18 p.c. concrete overlaid bridge decks in Iowa using the infrared thermography method of detecting delaminations.
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This project utilized information from ground penetrating radar (GPR) and visual inspection via the pavement profile scanner (PPS) in proof-of-concept trials. GPR tests were carried out on a variety of portland cement concrete pavements and laboratory concrete specimens. Results indicated that the higher frequency GPR antennas were capable of detecting subsurface distress in two of the three pavement sites investigated. However, the GPR systems failed to detect distress in one pavement site that exhibited extensive cracking. Laboratory experiments indicated that moisture conditions in the cracked pavement probably explain the failure. Accurate surveys need to account for moisture in the pavement slab. Importantly, however, once the pavement site exhibits severe surface cracking, there is little need for GPR, which is primarily used to detect distress that is not observed visually. Two visual inspections were also conducted for this study by personnel from Mandli Communications, Inc., and the Iowa Department of Transportation (DOT). The surveys were conducted using an Iowa DOT video log van that Mandli had fitted with additional equipment. The first survey was an extended demonstration of the PPS system. The second survey utilized the PPS with a downward imaging system that provided high-resolution pavement images. Experimental difficulties occurred during both studies; however, enough information was extracted to consider both surveys successful in identifying pavement surface distress. The results obtained from both GPR testing and visual inspections were helpful in identifying sites that exhibited materials-related distress, and both were considered to have passed the proof-of-concept trials. However, neither method can currently diagnose materials-related distress. Both techniques only detected the symptoms of materials-related distress; the actual diagnosis still relied on coring and subsequent petrographic examination. Both technologies are currently in rapid development, and the limitations may be overcome as the technologies advance and mature.
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Intrusion of deicing materials and surface water into concrete bridge decks is a main contributor in deck reinforcing steel corrosion and concrete delamination. Salt, spread on bridge decks to melt ice, dissolves in water and permeates voids in the concrete deck. When the chloride content of the concrete in contact with reinforcing steel reaches a high enough concentration, the steel oxidizes. In Iowa, the method used to reduce bridge deck chloride penetration is the application of a low slump dense concrete overlay after the completion of all Class A and Class B floor repairs. A possible alternative to the use of dense concrete overlays, developed by Poly-Carb, Inc., is the MARK-163 FLEXOGRID Overlay System. FLEXOGRID is a two component system of epoxy and urethane which is applied on a bridge deck to a minimum thickness of ¼ inch. An aggregate mixture of silica quartz and aluminum oxide is broadcast onto the epoxy at a prescribed rate to provide deck protection and superior friction properties. The material is mixed on site and applied to the deck in a series of lifts (usually two) until the desired overlay thickness has been attained.
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Computer-Aided Tomography Angiography (CTA) images are the standard for assessing Peripheral artery disease (PAD). This paper presents a Computer Aided Detection (CAD) and Computer Aided Measurement (CAM) system for PAD. The CAD stage detects the arterial network using a 3D region growing method and a fast 3D morphology operation. The CAM stage aims to accurately measure the artery diameters from the detected vessel centerline, compensating for the partial volume effect using Expectation Maximization (EM) and a Markov Random field (MRF). The system has been evaluated on phantom data and also applied to fifteen (15) CTA datasets, where the detection accuracy of stenosis was 88% and the measurement accuracy was with an 8% error.
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Chemosensory receptor gene families encode divergent proteins capable of detecting a huge diversity of environmental stimuli that are constantly changing over evolutionary time as organisms adapt to distinct ecological niches. While olfaction is dedicated to the detection of volatile compounds, taste is key to assess food quality for nutritional value and presence of toxic substances. The sense of taste also provides initial signals to mediate endocrine regulation of appetite and food metabolism and plays a role in kin recognition. The fruit fly Drosophila melanogaster is a very good model for studying smell and taste because these senses are very important in insects and because a broad variety of genetic tools are available in Drosophila. Recently, a family of 66 chemosensory receptors, the Ionotropic Receptors (IRs) was described in fruit flies. IRs are distantly related to ionotropic glutamate receptors (iGluRs), but their evolutionary origin from these synaptic receptors is unclear. While 16 IRs are expressed in the olfactory system, nothing is known about the other members of this repertoire. In this thesis, I describe bioinformatic, expression and functional analyses of the IRs aimed at understanding how these receptors have evolved, and at characterising the role of the non-olfactory IRs. I show that these have emerged at the basis of the protostome lineage and probably have acquired their sensory function very early. Moreover, although several IRs are conserved across insects, there are rapid and dramatic changes in the size and divergence of IR repertoires across species. I then performed a comprehensive analysis of IR expression in the larva of Drosophila melanogaster, which is a good model to study taste and feeding mechanisms as it spends most of its time eating or foraging. I found that most of the divergent members of the IR repertoire are expressed in both peripheral and internal gustatory neurons, suggesting that these are involved in taste perception. Finally, through the establishment of a new neurophysiological assay in larvae, I identified for the first time subsets of IR neurons that preferentially detect sugars and amino acids, indicating that IRs might be involved in sensing these compounds. Together, my results indicate that IRs are an evolutionarily dynamic and functionally versatile family of receptors. In contrast to the olfactory IRs that are well-conserved, gustatory IRs are rapidly evolving species-specific receptors that are likely to be involved in detecting a wide variety of tastants. - La plupart des animaux possèdent de grandes familles de récepteurs chimiosensoriels dont la fonction est de détecter l'immense diversité de composés chimiques présents dans l'environnement. Ces récepteurs évoluent en même temps que les organismes s'adaptent à leur écosystème. Il existe deux manières de percevoir ces signaux chimiques : l'olfaction et le goût. Alors que le système olfactif perçoit les composés volatiles, le sens du goût permet d'évaluer, par contact, la qualité de la nourriture, de détecter des substances toxiques et de réguler l'appétit et le métabolisme. L'un des organismes modèles les plus pertinents pour étudier le sens du goût est le stade larvaire de la mouche du vinaigre Drosophila melanogaster. En effet, la principale fonction du stade larvaire est de trouver de la nourriture et de manger. De plus, il est possible d'utiliser tous les outils génétiques développés chez la drosophile. Récemment, une nouvelle famille de 66 récepteurs chimiosensoriels appelés Récepteurs Ionotropiques (IRs) a été découverte chez la drosophile. Bien que leur orogine soit peu claire, ces récepteurs sont similaires aux récepteurs ionotropiques glutamatergiques impliqués dans la transmission synaptique. 16 IRs sont exprimés dans le système olfactif de la mouche adulte, mais pour l'instant on ne connaît rien des autres membres de cette famille. Durant ma thèse, j'ai effectué des recherches sur l'évolution de ces récepteurs ainsi que sur l'expression et la fonction des IRs non olfactifs. Je démontre que les IRs sont apparus chez l'ancêtre commun des protostomiens et ont probablement acquis leur fonction sensorielle très rapidement. De plus, bien qu'un certain nombre d'IRs olfactifs soient conservés chez les insectes, d'importantes variations dans la taille et la divergence des répertoires d'IRs entre les espèces ont été constatées. J'ai également découvert qu'un grand nombre d'IRs non olfactifs sont exprimés dans différents organes gustatifs, ce qui leur confère probablement une fonction dans la perception des goûts. Finalement, pour la première fois, des neurones exprimant des IRs ont été identifiés pour leur fonction dans la perception de sucres et d'acides aminés chez la larve. Mes résultats présentent les IRs comme une famille très dynamique, aux fonctions très variées, qui joue un rôle tant dans l'odorat que dans le goût, et dont la fonction est restée importante tout au long de l'évolution. De plus, l'identification de neurones spécialisés dans la perception de certains composés permettra l'étude des circuits neuronaux impliqués dans le traitement de ces informations.
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Understanding the emplacement and growth of intrusive bodies in terms of mechanism, duration, ther¬mal evolution and rates are fundamental aspects of crustal evolution. Recent studies show that many plutons grow in several Ma by in situ accretion of discrete magma pulses, which constitute small-scale magmatic reservoirs. The residence time of magmas, and hence their capacities to interact and differentiate, are con¬trolled by the local thermal environment. The latter is highly dependant on 1) the emplacement depth, 2) the magmas and country rock composition, 3) the country rock thermal conductivity, 4) the rate of magma injection and 5) the geometry of the intrusion. In shallow level plutons, where magmas solidify quickly, evi¬dence for magma mixing and/or differentiation processes is considered by many authors to be inherited from deeper levels. This work shows however that in-situ differentiation and magma interactions occurred within basaltic and felsic sills at shallow depth (0.3 GPa) in the St-Jean-du-Doigt (SJDD) bimodal intrusion, France. This intrusion emplaced ca. 347 Ma ago (IDTIMS U/Pb on zircon) in the Precambrian crust of the Armori- can massif and preserves remarkable sill-like emplacement processes of bimodal mafic-felsic magmas. Field evidence coupled to high precision zircon U-Pb dating document progressive thermal maturation within the incrementally built ioppolith. Early m-thick mafic sills (eastern part) form the roof of the intrusion and are homogeneous and fine-grained with planar contacts with neighboring felsic sills; within a minimal 0.8 Ma time span, the system gets warmer (western part). Sills are emplaced by under-accretion under the old east¬ern part, interact and mingle. A striking feature of this younger, warmer part is in-situ differentiation of the mafic sills in the top 40 cm of the layer, which suggests liquids survival in the shallow crust. Rheological and thermal models were performed in order to determine the parameters required to allow this observed in- situ differentiation-accumulation processes. Strong constraints such as total emplacement durations (ca. 0.8 Ma, TIMS date) and pluton thickness (1.5 Km, gravity model) allow a quantitative estimation of the various parameters required (injection rates, incubation time,...). The results show that in-situ differentiation may be achieved in less than 10 years at such shallow depth, provided that: (1) The differentiating sills are injected beneath consolidated, yet still warm basalt sills, which act as low conductive insulating screens (eastern part formation in the SJDD intrusion). The latter are emplaced in a very short time (800 years) at high injection rate (0.5 m/y) in order to create a "hot zone" in the shallow crust (incubation time). This implies that nearly 1/3 of the pluton (400m) is emplaced by a subsequent and sustained magmatic activity occurring on a short time scale at the very beginning of the system. (2) Once incubation time is achieved, the calculations show that a small hot zone is created at the base of the sill pile, where new injections stay above their solidus T°C and may interact and differentiate. Extraction of differentiated residual liquids might eventually take place and mix with newly injected magma as documented in active syn-emplacement shear-zones within the "warm" part of the pluton. (3) Finally, the model show that in order to maintain a permanent hot zone at shallow level, injection rate must be of 0.03 m/y with injection of 5m thick basaltic sills eveiy 130yr, imply¬ing formation of a 15 km thick pluton. As this thickness is in contradiction with the one calculated for SJDD (1.5 Km) and exceed much the average thickness observed for many shallow level plutons, I infer that there is no permanent hot zone (or magma chambers) at such shallow level. I rather propose formation of small, ephemeral (10-15yr) reservoirs, which represent only small portions of the final size of the pluton. Thermal calculations show that, in the case of SJDD, 5m thick basaltic sills emplaced every 1500 y, allow formation of such ephemeral reservoirs. The latter are formed by several sills, which are in a mushy state and may interact and differentiate during a short time.The mineralogical, chemical and isotopic data presented in this study suggest a signature intermediate be¬tween E-MORB- and arc-like for the SJDD mafic sills and feeder dykes. The mantle source involved produced hydrated magmas and may be astenosphere modified by "arc-type" components, probably related to a sub¬ducting slab. Combined fluid mobile/immobile trace elements and Sr-Nd isotopes suggest that such subduc¬tion components are mainly fluids derived from altered oceanic crust with minor effect from the subducted sediments. Close match between the SJDD compositions and BABB may point to a continental back-arc setting with little crustal contamination. If so, the SjDD intrusion is a major witness of an extensional tectonic regime during the Early-Carboniferous, linked to the subduction of the Rheno-Hercynian Ocean beneath the Variscan terranes. Also of interest is the unusual association of cogenetic (same isotopic compositions) K-feldspar A- type granite and albite-granite. A-type granites may form by magma mixing between the mafic magma and crustal melts. Alternatively, they might derive from the melting of a biotite-bearing quartz-feldspathic crustal protolith triggered by early mafic injections at low crustal levels. Albite-granite may form by plagioclase cu¬mulate remelting issued from A-type magma differentiation.
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INTRODUCTION: In alpine skiing, chronometry analysis is currently the most common tool to assess performance. It is widely used to rank competitors during races, as well as to manage athletes training and to evaluate material. Usually, this measurement is accurately realized using timing cells. Nevertheless, these devices are too complex and expensive to allow chronometry of every gates crossing. On the other side, differential GPS can be used for measuring gate crossing time (Waegli et al). However, this is complex (e.g. recording gate position with GPS) and mainly used in research applications. The aim of the study was to propose a wearable system to time gates crossing during alpine skiing slalom (SL), which is suitable for routine uses. METHODS: The proposed system was composed of a 3D accelerometer (ADXL320®, Analog Device, USA) placed at the sacrum of the athlete, a matrix of force sensors (Flexiforce®, Tekscan, USA) fixed on the right shin guard and a data logger (Physilog®, BioAGM, Switzerland). The sensors were sampled at 500 Hz. The crossing time were calculated in two phases. First, the accelerometer was used to detect the curves by considering the maximum of the mediolateral peak acceleration. Then, the force sensors were used to detect the impacts with the gates by considering maximum force variation. In case of non impact, the detection was realized based on the acceleration and features measured at the other gates. In order to assess the efficiency of the system, two different SL were monitored twice for two world cup level skiers, a male SL expert and a female downhill expert. RESULTS AND DISCUSSION: The combination of the accelerometer and force sensors allowed to clearly identify the gate crossing times. When comparing the runs of the SL expert and the downhill expert, we noticed that the SL expert was faster. For example for the first SL, the overall difference between the best run of each athlete was of 5.47s. At each gate, the SL expert increased the time difference slower at the beginning (0.27s/gate) than at the end (0.34s/gate). Furthermore, when comparing the runs of the SL expert, a maximum time difference of 20ms at each gate was noticed. This showed high repeatability skills of the SL expert. In opposite, the downhill expert with a maximum difference time of 1s at each gate was clearly less repeatable. Both skiers were not disturbed by the system. CONCLUSION: This study proposed a new wearable system to automatically time gates crossing during alpine skiing slalom combining force and accelerometer sensors. The system was evaluated with two professional world cup skiers and showed a high potential. This system could be extended to time other parameters. REFERENCES Waegli A, Skaloud J (2007). Inside GNSS, Spring, 24-34.
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Many audio watermarking schemes divide the audio signal into several blocks such that part of the watermark is embedded into each of them. One of the key issues in these block-oriented watermarking schemes is to preserve the synchronisation, i.e. to recover the exact position of each block in the mark recovery process. In this paper, a novel time domain synchronisation technique is presented together with a new blind watermarking scheme which works in the Discrete Fourier Transform (DFT or FFT) domain. The combined scheme provides excellent imperceptibility results whilst achieving robustness against typical attacks. Furthermore, the execution of the scheme is fast enough to be used in real-time applications. The excellent transparency of the embedding algorithm makes it particularly useful for professional applications, such as the embedding of monitoring information in broadcast signals. The scheme is also compared with some recent results of the literature.
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Manet security has a lot of open issues. Due to its character-istics, this kind of network needs preventive and corrective protection. Inthis paper, we focus on corrective protection proposing an anomaly IDSmodel for Manet. The design and development of the IDS are consideredin our 3 main stages: normal behavior construction, anomaly detectionand model update. A parametrical mixture model is used for behav-ior modeling from reference data. The associated Bayesian classi¯cationleads to the detection algorithm. MIB variables are used to provide IDSneeded information. Experiments of DoS and scanner attacks validatingthe model are presented as well.
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In this paper, two probabilistic adaptive algorithmsfor jointly detecting active users in a DS-CDMA system arereported. The first one, which is based on the theory of hiddenMarkov models (HMM’s) and the Baum–Wech (BW) algorithm,is proposed within the CDMA scenario and compared withthe second one, which is a previously developed Viterbi-basedalgorithm. Both techniques are completely blind in the sense thatno knowledge of the signatures, channel state information, ortraining sequences is required for any user. Once convergencehas been achieved, an estimate of the signature of each userconvolved with its physical channel response (CR) and estimateddata sequences are provided. This CR estimate can be used toswitch to any decision-directed (DD) adaptation scheme. Performanceof the algorithms is verified via simulations as well as onexperimental data obtained in an underwater acoustics (UWA)environment. In both cases, performance is found to be highlysatisfactory, showing the near–far resistance of the analyzed algorithms.
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Työ sisältää ohjaislaitteiston vertailun ja valinnan rinnakkaisrakenteista robottia varten sekä kunnonvalvontajärjestelmän periaatteiden laadinnan kyseistä robottia varten. Ohjauslaitteisto sisältää teollisuustietokoneen sekä kenttäväylän. Sekä tietokoneesta että väylästä on teoriaosuus ja yksityiskohtaisempi valintaosuus. Teoriaosuudessa selitetään tarkemmin laitteiden toimintaperiaatteista. Valintaosuudessa kerrotaanmiksi jokin tietty laite on valittu käytettäväksi robotin ohjauksessa. Kunnonvalvontateoria ja rinnakkaisrakenteisen robotin kunnonvalvonnan keinot ovat työn toinen osa. Teoriaosa sisältää yleisluonteisen selvityksen vikaantumisesta ja valvonnasta. Erikoisrobotin kunnonvalvonnan keinot esitetään työssä tietyssä järjestyksessä. Ensin esitetään mahdolliset vikatilanteet. Toisessa kohdassa havainnollistetaan vikojen havaitseminen.
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This study examines cases of chronic drug users who died suddenly after drug administration. Victims were young subjects, aged from 19 to 35 from Switzerland and known to the police as long-term drug users. The circumstances of death suggested the occurrence of a sudden, unexpected death. Some victims were undergoing methadone treatment. In each case, a forensic autopsy and toxicological analyses were performed at the Institute of Forensic Medicine in Lausanne in Switzerland between 2002 and 2004, including hair analysis as a means to establish chronic drug use in general, and cocaine use in particular. The conduction system was examined histologically and cases showing potentially lethal changes were chosen for this report. The most frequent lesions found were severe thickening of the atrioventricular node artery, intranodal and perinodal fibrosis, and microscopic foci of chronic inflammatory infiltration. The authors conclude that pathological lesions in the conduction tissue may play a role in the occurrence of death attributed to intoxication consecutive to cocaine ingestion.
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Tässä diplomityössä tutkitaan tekniikoita, joillavesileima lisätään spektrikuvaan, ja menetelmiä, joilla vesileimat tunnistetaanja havaitaan spektrikuvista. PCA (Principal Component Analysis) -algoritmia käyttäen alkuperäisten kuvien spektriulottuvuutta vähennettiin. Vesileiman lisääminen spektrikuvaan suoritettiin muunnosavaruudessa. Ehdotetun mallin mukaisesti muunnosavaruuden komponentti korvattiin vesileiman ja toisen muunnosavaruuden komponentin lineaarikombinaatiolla. Lisäyksessä käytettävää parametrijoukkoa tutkittiin. Vesileimattujen kuvien laatu mitattiin ja analysoitiin. Suositukset vesileiman lisäykseen esitettiin. Useita menetelmiä käytettiin vesileimojen tunnistamiseen ja tunnistamisen tulokset analysoitiin. Vesileimojen kyky sietää erilaisia hyökkäyksiä tarkistettiin. Diplomityössä suoritettiin joukko havaitsemis-kokeita ottamalla huomioon vesileiman lisäyksessä käytetyt parametrit. ICA (Independent Component Analysis) -menetelmää pidetään yhtenä mahdollisena vaihtoehtona vesileiman havaitsemisessa.
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CERNin tutkimuskeskuksen rakenteilla olevan hadronikiihdyttimen eräs tarkoitus on todistaa Higgsin bosonin olemassaolo. Higgsin bosonin löytyminen yhtenäistäisi nykyisen hiukkasfysiikan teorian ja antaisi selityksen sille kuinka hiukkaset saavat massansa. Kiihdyttimen CMS koeasema on tarkoitettu erityisesti myonien ilmaisuun. Tämä työ liittyy CMS koeaseman RPC-ilmaisintyypin linkkijärjestelmään, jonka tarkoituksena on käsitellä ilmaisimelta tulevia myonien aiheuttamia signaaleja ja lähettää tiedot tärkeäksi katsotuista törmäystapahtumista tallennettavaksi analysointia varten. Työssä on toteutettu linkkijärjestelmän ohjaus- ja linkkikorteille testiympäristö, jolla voidaan todeta järjestelmän eri osien keskinäinen yhteensopivuus ja toimivuus. Työn alkuosassa esitellään ilmaisimen linkkijärjestelmän eri osat ja niiden merkitykset. Työn loppuosassa käydään läpi eri testimenetelmiä ja analysoidaan niiden antamia tuloksia.
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Euroopan hiukkastutkimuslaitoksen CERNin rakenteilla olevan LHC-hiukkaskiihdyttimen CMS-koeasema on tarkoitettu erityisesti myonin ilmaisuun. Tässä työssä on esitelty CMS-koeaseman RPC-ilmaisintyypin linkkijärjestelmä ja sen testaamiseen tarkoitetut laitteet sekä laitteiden testaamiseen tarvittavat ohjelmistot. Työssä on selvitetty ohjelmien toimivuus ja keskinäinen yhteensopivuus.