Reconeixement de veu mitjançant xarxes neuronals

La interacció home-màquina per mitjà de la veu cobreix moltes àrees d’investigació. Es destaquen entre altres, el reconeixement de la parla, la síntesis i identificació de discurs, la verificació i identificació de locutor i l’activació per veu (ordres) de sistemes robòtics. Reconèixer la parla és natural i simple per a les persones, però és un treball complex per a les màquines, pel qual existeixen diverses metodologies i tècniques, entre elles les Xarxes Neuronals. L’objectiu d’aquest treball és desenvolupar una eina en Matlab per al reconeixement i identificació de paraules pronunciades per un locutor, entre un conjunt de paraules possibles, i amb una bona fiabilitat dins d’uns marges preestablerts. El sistema és independent del locutor que pronuncia la paraula, és a dir, aquest locutor no haurà intervingut en el procés d’entrenament del sistema. S’ha dissenyat una interfície que permet l’adquisició del senyal de veu i el seu processament mitjançant xarxes neuronals i altres tècniques. Adaptant una part de control al sistema, es podria utilitzar per donar ordres a un robot com l’Alfa6Uvic o qualsevol altre dispositiu.

Safety and accuracy of robot-assisted versus fluoroscopy-guided pedicle screw insertion for degenerative diseases of the lumbar spine: a matched cohort comparison.

Object Recent years have been marked by efforts to improve the quality and safety of pedicle screw placement in spinal instrumentation. The aim of the present study is to compare the accuracy of the SpineAssist robot system with conventional fluoroscopy-guided pedicle screw placement. Methods Ninety-five patients suffering from degenerative disease and requiring elective lumbar instrumentation were included in the study. The robot cohort (Group I; 55 patients, 244 screws) consisted of an initial open robot-assisted subgroup (Subgroup IA; 17 patients, 83 screws) and a percutaneous cohort (Subgroup IB, 38 patients, 161 screws). In these groups, pedicle screws were placed under robotic guidance and lateral fluoroscopic control. In the fluoroscopy-guided cohort (Group II; 40 patients, 163 screws) screws were inserted using anatomical landmarks and lateral fluoroscopic guidance. The primary outcome measure was accuracy of screw placement on the Gertzbein-Robbins scale (Grade A to E and R [revised]). Secondary parameters were duration of surgery, blood loss, cumulative morphine, and length of stay. Results In the robot group (Group I), a perfect trajectory (A) was observed in 204 screws (83.6%). The remaining screws were graded B (n = 19 [7.8%]), C (n = 9 [3.7%]), D (n = 4 [1.6%]), E (n = 2 [0.8%]), and R (n = 6 [2.5%]). In the fluoroscopy-guided group (Group II), a completely intrapedicular course graded A was found in 79.8% (n = 130). The remaining screws were graded B (n = 12 [7.4%]), C (n = 10 [6.1%]), D (n = 6 [3.7%]), and E (n = 5 [3.1%]). The comparison of "clinically acceptable" (that is, A and B screws) was neither different between groups (I vs II [p = 0.19]) nor subgroups (Subgroup IA vs IB [p = 0.81]; Subgroup IA vs Group II [p = 0.53]; Subgroup IB vs Group II [p = 0.20]). Blood loss was lower in the robot-assisted group than in the fluoroscopy-guided group, while duration of surgery, length of stay, and cumulative morphine dose were not statistically different. Conclusions Robot-guided pedicle screw placement is a safe and useful tool for assisting spine surgeons in degenerative spine cases. Nonetheless, technical difficulties remain and fluoroscopy backup is advocated.

DNA extraction using the QIAsymphony: Evaluation of PCR inhibitor removal

The goal of this study was to compare the quantity and purity of DNA extracted from biological tracesusing the QIAsymphony robot with that of the manual QIAamp DNA mini kit currently in use in ourlaboratory. We found that the DNA yield of robot was 1.6-3.5 times lower than that of the manualprotocol. This resulted in a loss of 8% and 29% of the alleles correctly scored when analyzing 1/400 and 1/800 diluted saliva samples, respectively. Specific tests showed that the QIAsymphony was at least 2-16times more efficient at removing PCR inhibitors. The higher purity of the DNA may therefore partlycompensate for the lower DNA yield obtained. No case of cross-contamination was observed amongsamples. After purification with the robot, DNA extracts can be automatically transferred in 96-wellsplates, which is an ideal format for subsequent RT-qPCR quantification and DNA amplification. Lesshands-on time and reduced risk of operational errors represent additional advantages of the robotic platform.

Volcanic stratigraphy of Hannah Point, Livingston Island, South Shetland Islands, Antarctica

The Upper Cretaceous volcanic succession of Hannah Point is the best exposure of the Antarctic Peninsula Volcanic Group on L ivingston Island. The aim of the present paper is to contribute to the characterisation of the stratigr a p hy and petrogr a p hy of this little studied succession, and briefly discuss some aspects of the eru p t ive style of its volcanism. The succession is about 470 m thick and is here subdivided into five lithostratigraphic units (A to E from base to top). Unit A, approximately 120 m thick, is mainly composed of polymict clast-supported volcaniclastic breccias and also includes a dacitic lava laye r. Interstratified in the breccias of this unit, there is a thin laminated devitrified layer which shows some degree of welding. Unit B, approx imately 70 m thick, is almost entirely composed of volcaniclastic breccias, and includes a volcaniclastic conglomerate laye r. Breccias in this unit can be subdivided into two distinct types; polymict clast-supported breccias, and monomict matrix-supported breccias rich in juvenile components and displaying incipient welding. Unit C, about 65 m thick, is mainly composed of basaltic lavas, which are interlayered with minor vo lcaniclastic breccias. Unit D, approximately 65 m thick, is lithologically similar to unit B, composed of an alternation of polymict clasts upported breccias and matrix-supported breccias, and includes a volcaniclastic conglomerate laye r. Unit E, about 150 m thick, is mainly formed of thick andesitic lava layers. Minor basaltic dykes and a few normal faults cut the succession, and the contact betwe e n units A and B can be interpreted both as an unconformity or a fault. The matrix-supported breccias included in the succession of Hannah Point have high contents of juvenile components and incipient welding, which suggest that part of the succession is the result of pyroclastic fragmentation and emplacement from pyroclastic flows. In contrast, the polymict clast-supported breccias suggest reworking of previous deposits and deposition from cool mass flows. The lavas indicate eff u s ive volcanic eruptions, and the absence of features indicative of subaqueous volcanism suggests that at least these portions of the succession were emplaced in a subaerial environment .

The biogenic origin of needle fibre calcite

Needle fibre calcite is one of the most ubiquitous habits of calcite in vadose environments (caves deposits, soil pores, etc.). Its origin, either through inorganic, indirect or direct biological processes, has long been debated. In this study, investigations at 11 sites in Europe, Africa and Central America support arguments for its biogenic origin. The wide range of needle morphologies is the result of a gradual evolution of the simplest type, a rod. This rod is the elementary brick which, by aggregation and welding, builds more complex needles. The absence of cross-welded needles implies that they are welded in a mould, or under a longitudinal and unidirectional constraint, before being released inside the soil pores. The difference between the lengthening of the needles and the c axis can be explained by the existence of needles observed under a scanning electron microscope in organic sleeves, which can act as a mould during rod growth. Complex morphologies with epitaxial outgrowths on straight rods cannot have grown entirely inside organic microtubes; they must result from soil diagenesis after the release of straight rods in a soil-free medium. Whisker crystals are interpreted as the result of growth and coalescence of euhedral crystals on a rod. Rhomb chains are considered to be the consequence of successive epitaxial growth steps on a needle during variations in growth conditions. Isotopic signatures for needle fibre calcite vary from -16.63[per mille] to +1.10[per mille] and from -8.63[per mille] to -2.25[per mille] for Delta13C and Delta18O, respectively. The absence of high Delta18O values for needle fibre calcite precludes a purely physicochemical origin (evaporative) for this particular habit of calcite. As epitaxial growth cannot precipitate in the same conditions as initial needles, needle fibre calcite stable isotopic signatures should be used with caution as a proxy for palaeoenvironmental reconstructions. In addition, it is suggested that the term needle fibre calcite should be kept for the original biogenic form. The other habit should be referred to as epitaxial forms of needle fibre calcite.

Laparoscopie abdominale: possibilités et limites [Abdominal laparoscopy: an update]

Laparoscopic surgery has become a standard approach for many interventions, including oncologic surgery. Laparoscopic instruments have been developed to allow advanced surgical procedure. Imaging and computer assistance in virtual reality or robotic procedure will certainly improve access to this surgery.

Pédiatrie. 3. Traitement du membre supérieur dans les hémiparésies congénitales: progrès et perspectives [Pediatrics. Upper limb treatment in congenital hemiparesis: progress and perspectives].

Congenital hemiparesis is one of the most frequent pediatric motor disorders. Upper limb rehabilitation of the hemiparetic child has considerably evolved during the last decade by the use of focal chemical denervation (intramuscular botulinum toxin) and the introduction of novel rehabilitation techniques such as constraint induced movement therapy or robotic reeducation.

The Flexural Fatigue Strength of Prestressed Steel I-Beams, HR-73, 1962

The purpose of this investigation was to study the flexural fatigue strength of two prestressed steel I-beams which had previously been fabricated in connection with a jointly sponsored project under the auspices of the Iowa State Highway Commission. The beams were prestressed by deflecting them under the action of a concentrated load at the center of a simple span, then welding unstressed high strength steel plates to the top and bottom flanges to retain a predetermined amount of prestress. The beams were rolled sections of A36 steel and the plates were USS "T-1" steel. Each of the two test specimens were subjected to an identical repeated loading until a fatigue failure occurred. The loading was designed to produce stresses equivalent to those which would have occurred in a simulated bridge and amounted to 84 percent of a standard H-15 live load including impact. One of the beams sustained 2,469,100 repetitions of load to failure and the other sustained 2,756,100 cycles. Following the fatigue tests, an experimental study was made to determine the state of stress that had been retained in the prestressed steel beams. This information, upon which the calculated stresses of the test could be superimposed, provided a method of correlating the fatigue strength of the beams with the fatigue information available on the two steels involved.

Wind Loads on Dynamic Message Cabinets and Behavior of Supporting Trusses, TR-612, 2013

Large Dynamic Message Signs (DMSs) have been increasingly used on freeways, expressways and major arterials to better manage the traffic flow by providing accurate and timely information to drivers. Overhead truss structures are typically employed to support those DMSs allowing them to provide wider display to more lanes. In recent years, there is increasing evidence that the truss structures supporting these large and heavy signs are subjected to much more complex loadings than are typically accounted for in the codified design procedures. Consequently, some of these structures have required frequent inspections, retrofitting, and even premature replacement. Two manufacturing processes are primarily utilized on truss structures - welding and bolting. Recently, cracks at welding toes were reported for the structures employed in some states. Extremely large loads (e.g., due to high winds) could cause brittle fractures, and cyclic vibration (e.g., due to diurnal variation in temperature or due to oscillations in the wind force induced by vortex shedding behind the DMS) may lead to fatigue damage, as these are two major failures for the metallic material. Wind and strain resulting from temperature changes are the main loads that affect the structures during their lifetime. The American Association of State Highway and Transportation Officials (AASHTO) Specification defines the limit loads in dead load, wind load, ice load, and fatigue design for natural wind gust and truck-induced gust. The objectives of this study are to investigate wind and thermal effects in the bridge type overhead DMS truss structures and improve the current design specifications (e.g., for thermal design). In order to accomplish the objective, it is necessary to study structural behavior and detailed strain-stress of the truss structures caused by wind load on the DMS cabinet and thermal load on the truss supporting the DMS cabinet. The study is divided into two parts. The Computational Fluid Dynamics (CFD) component and part of the structural analysis component of the study were conducted at the University of Iowa while the field study and related structural analysis computations were conducted at the Iowa State University. The CFD simulations were used to determine the air-induced forces (wind loads) on the DMS cabinets and the finite element analysis was used to determine the response of the supporting trusses to these pressure forces. The field observation portion consisted of short-term monitoring of several DMS Cabinet/Trusses and long-term monitoring of one DMS Cabinet/Truss. The short-term monitoring was a single (or two) day event in which several message sign panel/trusses were tested. The long-term monitoring field study extended over several months. Analysis of the data focused on trying to identify important behaviors under both ambient and truck induced winds and the effect of daily temperature changes. Results of the CFD investigation, field experiments and structural analysis of the wind induced forces on the DMS cabinets and their effect on the supporting trusses showed that the passage of trucks cannot be responsible for the problems observed to develop at trusses supporting DMS cabinets. Rather the data pointed toward the important effect of the thermal load induced by cyclic (diurnal) variations of the temperature. Thermal influence is not discussed in the specification, either in limit load or fatigue design. Although the frequency of the thermal load is low, results showed that when temperature range is large the restress range would be significant to the structure, especially near welding areas where stress concentrations may occur. Moreover stress amplitude and range are the primary parameters for brittle fracture and fatigue life estimation. Long-term field monitoring of one of the overhead truss structures in Iowa was used as the research baseline to estimate the effects of diurnal temperature changes to fatigue damage. The evaluation of the collected data is an important approach for understanding the structural behavior and for the advancement of future code provisions. Finite element modeling was developed to estimate the strain and stress magnitudes, which were compared with the field monitoring data. Fatigue life of the truss structures was also estimated based on AASHTO specifications and the numerical modeling. The main conclusion of the study is that thermal induced fatigue damage of the truss structures supporting DMS cabinets is likely a significant contributing cause for the cracks observed to develop at such structures. Other probable causes for fatigue damage not investigated in this study are the cyclic oscillations of the total wind load associated with the vortex shedding behind the DMS cabinet at high wind conditions and fabrication tolerances and induced stresses due to fitting of tube to tube connections.

Beaming into the rat world: enabling real-time intereaction between rat and human each at their own scale

Immersive virtual reality (IVR) typically generates the illusion in participants that they are in the displayed virtual scene where they can experience and interact in events as if they were really happening. Teleoperator (TO) systems place people at a remote physical destination embodied as a robotic device, and where typically participants have the sensation of being at the destination, with the ability to interact with entities there. In this paper, we show how to combine IVR and TO to allow a new class of application. The participant in the IVR is represented in the destination by a physical robot (TO) and simultaneously the remote place and entities within it are represented to the participant in the IVR. Hence, the IVR participant has a normal virtual reality experience, but where his or her actions and behaviour control the remote robot and can therefore have physical consequences. Here, we show how such a system can be deployed to allow a human and a rat to operate together, but the human interacting with the rat on a human scale, and the rat interacting with the human on the rat scale. The human is represented in a rat arena by a small robot that is slaved to the human"s movements, whereas the tracked rat is represented to the human in the virtual reality by a humanoid avatar. We describe the system and also a study that was designed to test whether humans can successfully play a game with the rat. The results show that the system functioned well and that the humans were able to interact with the rat to fulfil the tasks of the game. This system opens up the possibility of new applications in the life sciences involving participant observation of and interaction with animals but at human scale.

Improvement of rehabilitation possibilities with the MotionMaker (TM)

"MotionMaker (TM)" is a stationary programmable test and training system for the lower limbs developed at the 'Ecole Polytechnique Federale de Lausanne' with the 'Fondation Suisse pour les Cybertheses'.. The system is composed of two robotic orthoses comprising motors and sensors, and a control unit managing the trans-cutaneous electrical muscle stimulation with real-time regulation. The control of the Functional Electrical Stimulation (FES) induced muscle force necessary to mimic natural exercise is ensured by the control unit which receives a continuous input from the position and force sensors mounted on the robot. First results with control subjects showed the feasibility of creating movements by such closed-loop controlled FES induced muscle contractions. To make exercising with the MotionMaker (TM) safe for clinical trials with Spinal Cord Injured (SCI) volunteers, several original safety features have been introduced. The MotionMaker (TM) is able to identify and manage the occurrence of spasms. Fatigue can also be detected and overfatigue during exercise prevented.

Hiiliteräspalkin kuitulaserhitsaus

Hitsaavassa teollisuudessa kilpailukyvyn säilyttäminen ja mahdollinen parantaminen edellyttää hitsauksen tehokkuuden nostoa. Laserhitsauksen nopeus, tarkkuus, tasainen laatu ja aikaansaatava syvä tunkeuma ovatkin vakiinnuttaneet menetelmän vankan aseman tehokkaana valmistusmenetelmänä. Sähkön ja heliumin hinnan nousu ovat pakottaneet teollisuuden miettimään entistä tehokkaampien ja ympäristöystävällisempien laserlähteiden hankkimista. Kuitulaserin korkea hyötysuhde, hyvä säteenlaatu, suuri teho ja matalat käyttökustannukset ovat herättäneet kiinnostusta laserhitsaavassa teollisuudessa. Diplomityössä keskityttiin kuitulaserhitsauksen soveltamiseen. Työn tavoitteena oli parantaa kuitulaserhitsausmenetelmän ymmärrystä ja saada käsitys siitä, miten valitaan hitsausparametrien arvot, ja soveltuuko kuitulaser teolliseen tuotantoon. Tutkimuksessa pyrittiin löytämään peruskokeilla optimaaliset hitsausparametrit, joilla syntyy hyvin tunkeutunut, vähän huokosia sisältävä, ja ulkoisesti laadukas hitsi, sekä optimaalinen hitsin tunkeumaprofiili. Lopuksi hitsausparametreja testattiin tuotteen hitsauksessa. Kuitulaser soveltuu erinomaisesti hiiliteräksen hitsaukseen ja hyvin erikoislujien terästen hitsaukseen, kun teräksen hiili- ja rikkipitoisuudet ovat matalia. Sillä on laaja parametrialue. Yleisimmät hitsausvirheet ovat vajaa hitsautumissyvyys ja huokoset. Tässä diplomityössä keskityttiin etsimään yhdelle valmistettavalle tuotteelle optimaaliset kuitulaserhitsausparametrit. Kuitulaserin laser- ja prosessiparametrien vaikutusta hitsiin ei ole juurikaan tutkittu. Diplomityön kokeiden perusteella olisi hyvä tehdä eri materiaalien jatkotutkimusta railonvalmistuksen, kuten liitoksen oksidikerroksen ja ilmaraon sekä suojakaasun, vaikutuksesta hitsiin. Kuitulaserin hyvä säteenlaatu ja muut laser-parametrit ovat tuoneet mukanaan prosessiin uusia ilmiöitä, joita on syytä tutkia lisää.

Hitsausparametrien vaikutus rakenneteräksen MAG-hitsin laatuun

Työn tavoitteena oli löytää teräksen S355 MAG alapienahitsaukselle, 6mm:n levypaksuudelle sellaiset parametri-ikkunat, joissa hitsin ja perusaineen liittyminen on mahdollisimman jouheva. Hitsin laadunja hitsausparametrien välille pyritiin löytämään matemaattista korrelaatiota. Työ painottui hitsin muotoon sekä hitsin ja perusaineen liittymiseen. Työstä saatuja tuloksia käytettiin hitsattaessa väsytyskoekappaleita mutta niiden tutkiminen ei sisältynyt tähän työhön. Työssä haettiin parametreja a-mitaltaan 4mm:n alapienahitsille kahdeksalle yleisesti käytetylle hitsauslangalle, joista kolme oli umpilankaa, neljä metallitäytelankaa ja yksi rutiilitäytelanka ja kaasuina käytettiin kahta argon hiilidioksidi seoskaasua ja kahta argon helium seoskaasua.

LM-vesiturbiinin tuotteistaminen

Tämän työn tarkoituksena on kehittää LM-vesiturbiini tuotantoon soveltuvaksi, käytöltään pitkäikäiseksi ja helposti huollettavaksi tuotesarjaksi. Työn ohjaavana runkona on käytetty VDI-Richtlinie 2221: 'Kehitystyön ja konstruoinnin yleinen kulku', mukaista järjestelmää. Lisäksi on käytetty valmistuksellista modulointia tuotteen osien suunnittelussa. Erityisesti on huomioitu tuotteen koko elinkaaren aikaiset kustannukset (LCC) ja sen vaatimukset mitoitukseen. LM-vesiturbiinistaon kehitetty kolmen erikokoisen laitteiston tuotesarja. Tuoteperheen yksittäisistä sylinteriryhmistä voidaan koota joustavasti erikokoisia ja -tehoisia energiantuotantoyksiköitä, jotka soveltuvat käyttöön hyvin pieniinkin virtauksiin ja putouskorkeuksiin. Piensarjatuotantoon hyvin soveltuvat materiaalit on valittu silmälläpitäen mahdollisimman edullista kokonaiskustannusta. Kiertomäntä laitteiston toiminnan kannalta tärkeimpänä ja siten vaativimpana osana on edellyttänyt laserhitsausta ja -leikkausta sekä koekappaleiden valmistusta, joiden perusteellalopulliseen rakenteeseen on päädytty. Mitoitus perustuu perinteisiin lujuuslaskentamenetelmiin, joiden avulla eri osien kestävyys käyttöolosuhteissa on pyrittysaamaan luotettavaksi vähintään 20 vuoden kestoiälle ja väsymiskestävyyteen käytön aikaisissa vaihtelevissa olosuhteissa. Kiertomäntä on ns. kevytrakenne koostuen ohutlevykennorakenteesta ja täytteenä olevasta kompound-materiaalista.