bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial and temporal patterns of Risso’s dolphin echolocation in the Southern California Bight
Authors: Soldevilla Melissa S. , Wiggins Sean M. , Hildebrand John A.
Published: January 2010

Geographical and temporal trends in echolocation clicking activity can lead to insights into the foraging and migratory behaviors of pelagic dolphins. Using autonomous acoustic recording packages, the geographical, diel, and seasonal patterns of Risso’s dolphin (Grampus griseus) echolocation click activity are described for six locations in the Southern California Bight between 2005 and 2007. Risso’s dolphin echolocation click bouts are identified based on their unique spectral characteristics. Click bouts were identified on 739 of 1959 recording days at all 6 sites, with the majority occurring at nearshore sites. A significant diel pattern is evident in which both hourly occurrences of click bouts and click rates are higher at night than during the day. At all nearshore sites, Risso’s dolphin clicks were identified year-round, with the highest daily occurrence at the southern end of Santa Catalina Island. Seasonal and interannual variabilities in occurrence were high across sites with peak occurrence in autumn of most years at most sites. These results suggest that Risso’s dolphins forage at night and that the southern end of Santa Catalina Island represents an important habitat for Risso’s dolphins throughout the year.
A relation between electrode discrimination and amplitude modulation detection by cochlear implant listeners
Authors: Chatterjee Monita , Yu Jian
Published: January 2010

The objective of this study was to examine the relation between measures of spectral and temporal resolutions in cochlear implant listeners at a particular electrode location. The hypothesis was that a common underlying factor, such as the health of local groups of neurons, might partially determine patients’ sensitivity to both spectral and temporal cues at specific tonotopic locations. Participants were adult cochlear implant listeners. A significant correlation was found between electrode discrimination measured at soft levels (20% and 30% of the dynamic range) and modulation sensitivity at those levels, for stimulation in bipolar mode and a 100Hz modulation rate. Correlations between the two measures were weaker under monopolar stimulation, or when the modulation rate was 10Hz. At a higher stimulation level (40% of the dynamic range), no significant correlations between these measures were observed. It is hypothesized that the more restricted excitation pattern at lower levels and/or with a narrower stimulation mode allows the measurement of locally driven sensitivity to spectral and temporal cues, particularly under more challenging listening conditions. Thus, psychophysical measures obtained under conditions that evoke a narrower excitation pattern may serve as a useful indicator of the functional health of local neural populations.
Effective fractional acoustic wave equations in one-dimensional random multiscale media
Authors: Garnier Josselin , Sølna Knut
Published: January 2010

This paper considers multiple scattering of waves propagating in a non-lossy one-dimensional random medium with short- or long-range correlations. Using stochastic homogenization theory it is possible to show that pulse propagation is described by an effective deterministic fractional wave equation, which corresponds to an effective medium with a frequency-dependent attenuation that obeys a power law with an exponent between 0 and 2. The exponent is related to the Hurst parameter of the medium, which is a characteristic parameter of the correlation properties of the fluctuations of the random medium. Moreover the frequency-dependent attenuation is associated with a special frequency-dependent phase, which ensures that causality and Kramers–Kronig relations are satisfied. In the time domain the effective wave equation has the form of a linear integro-differential equation with a fractional derivative.
Experimental and theoretical study of acoustic waves generated by a laser line pulse in an optically absorptive isotropic cylinder
Authors: Ségur D. , Shuvalov A. L. , Audoin B. , Pan Y. D.
Published: January 2010

The generation of acoustic waves by a line-focused laser pulse in an optically absorptive cylinder is studied experimentally and theoretically. Experiments are performed on a 5 mm diameter NG5 colored glass rod using Nd:yttrium aluminum garnet laser, which delivers 5 ns pulses. The numerical simulation is based on the semi-analytical model of a radially distributed thermoelastic source, which takes into account penetration of laser energy into the bulk of the sample. Good agreement between the experimental and calculated wave forms is observed. Comparison of these wave forms with an auxiliary simulation, which assumes the model of a dipole source located at the cylinder surface, reveals the effect of optical penetration on the shape of the wave form and also on the relative amplitude of bulk and surface waves.
A method for finding constrictions in high front vowels
Authors: Jackson Michel T.-T. , McGowan Richard S.
Published: January 2010

The purpose of this study was to devise a consistent and robust method for defining vocal tract constrictions in high front vowels. A procedure was devised to find the length and position of the articulatory constriction in high front vowels that is not sensitive to local fluctuations in vocal tract shape and to the constriction-defining parameters. A method based on a visual examination of plots for constriction length and position as functions of the constriction-defining parameters was found to provide stable constriction definitions.
Perception of musical pitch and lexical tones by Mandarin-speaking musicians
Authors: Lee Chao-Yang , Lee Yuh-Fang
Published: January 2010

The relationship between music and language processing was explored in two perception experiments on the identification of musical notes and Mandarin tones. In the music task, Mandarin-speaking musicians were asked to identify musical notes of three timbres without a reference pitch. 72% of the musicians met the criterion for absolute pitch when an exact match was required, and 82% met the criterion when one-semitone errors were allowed. Accuracy of identification was negatively correlated with age of onset of musical training, and piano notes were identified more accurately than viola and pure tone stimuli. In the Mandarin task, the musicians were able to identify, beyond chance, brief Mandarin tone stimuli that were devoid of dynamic F0 information and cues commonly considered necessary for speaker normalization. Although F0 height detection was involved in both musical note and Mandarin tone identification, performances in the two tasks were not correlated. The putative link between absolute pitch and tone language experience was discussed.
Perceptual studies of violin body damping and vibrato
Authors: Fritz Claudia , Woodhouse Jim , Cheng Felicia P.-H. , Cross Ian , Blackwell Alan F. , Moore Brian C. J.
Published: January 2010

This work explored how the perception of violin notes is influenced by the magnitude of the applied vibrato and by the level of damping of the violin resonance modes. Damping influences the “peakiness” of the frequency response, and vibrato interacts with this peakiness by producing fluctuations in spectral content as well as in frequency and amplitude. Initially, it was shown that thresholds for detecting a change in vibrato amplitude were independent of body damping, and thresholds for detecting a change in body damping were independent of vibrato amplitude. A study of perceptual similarity using triadic comparison showed that vibrato amplitude and damping were largely perceived as independent dimensions. A series of listening tests was conducted employing synthesized, recorded, or live performance to probe perceptual responses in terms of “liveliness” and preference. The results do not support the conclusion that liveliness results from the combination of the use of vibrato and a “peaky” violin response. Judgments based on listening to single notes showed inconsistent patterns for liveliness, while preferences were highest for damping that was slightly less than for a reference (real) violin. In contrast, judgments by players based on many notes showed preference for damping close to the reference value.
Dislodgement and removal of dust-particles from a surface by a technique combining acoustic standing wave and airflow
Authors: Chen Di , Wu Junru
Published: January 2010

It is known that there are many fine particles on the moon and Mars. Their existence may cause risk for the success of a long-term project for NASA, i.e., exploration and habitation of the moon and Mars. These dust-particles might cover the solar panels, making them fail to generate electricity, and they might also penetrate through seals on space suits, hatches, and vehicle wheels causing many incidents. The fine particles would be hazardous to human health if they were inhaled. Development of robust dust mitigation technology is urgently needed for the viable long-term exploration and habilitation of either the moon or Mars. A feasibility study to develop a dust removal technique, which may be used in space-stations or other enclosures for habitation, is reported. It is shown experimentally that the acoustic radiation force produced by a 13.8kHz 128dB sound-level standing wave between a 3cm-aperture tweeter and a reflector separated by 9cm is strong enough to overcome the van der Waals adhesive force between the dust-particles and the reflector-surface. Thus the majority of fine particles (>2μm diameter) on a reflector-surface can be dislodged and removed by a technique combining acoustic levitation and airflow methods. The removal efficiency deteriorates for particles of less than 2μm in size.
Localization of sperm whales in a group using clicks received at two separated short baseline arrays
Authors: Hirotsu Ryo , Yanagisawa Masao , Ura Tamaki , Sakata Masao , Sugimatsu Harumi , Kojima Junichi , Bahl Rajendar
Published: January 2010

In this paper, a sperm whale click analysis scheme is proposed in order to calculate the position of individual sperm whales in a group using data received at two arrays deployed near the surface. The proposed method mainly consists of two parts: short baseline (SBL) with classification and long baseline (LBL) with class matching. In SBL with classification, a click is automatically detected, and its direction of arrival is calculated. The clicks are then classified based on their direction vectors. The class data are then sent together with direction data and matched to the other array’s class data. LBL with class matching is used for localization. The classification algorithm can be used to estimate the number of whales clicking and to list potential candidates for LBL matching. As a result, the proposed method is able to localize the positions of the whales in a group. The performance of the proposed method is evaluated using data recorded off Ogasawara islands with two arrays near the surface. The three-dimensional underwater trajectories of six sperm whales are extracted to demonstrate the capability of the proposed method.
Acoustic consequences of articulatory variability during productions of /t/ and /k/ and its implications for speech error research
Authors: Marin Stefania , Pouplier Marianne , Harrington Jonathan
Published: January 2010

An increasing number of studies has linked certain types of articulatory or acoustic variability with speech errors, but no study has yet examined the relationship between such articulatory variability and acoustics. The present study aims to evaluate the acoustic properties of articulatorily errorful /k/ and /t/ stimuli to determine whether these errors are consistently reflected in the acoustics. The most frequent error observed in the articulatory data is the production of /k/ and /t/ with simultaneous tongue tip and tongue dorsum constrictions. Spectral analysis of these stimuli’s bursts shows that /k/ and /t/ are differently affected by such co-production errors: co-production of tongue tip and tongue dorsum during intended /k/ results in typical /k/ spectra (and hence in tokens robustly classified as /k/), while co-productions during intended /t/ result in spectra with roughly equal prominence at both the mid-frequency (/k/-like) and high-frequency (/t/-like) ranges (and hence in tokens ambiguous between /k/ and /t/). This outcome is not due to an articulatory timing difference, but to tongue dorsum constriction having an overall greater effect on the acoustic than a tongue tip constriction when the two are co-produced.
Prediction of binaural speech intelligibility against noise in rooms
Authors: Lavandier Mathieu , Culling John F.
Published: January 2010

In the presence of competing speech or noise, reverberation degrades speech intelligibility not only by its direct effect on the target but also by affecting the interferer. Two experiments were designed to validate a method for predicting the loss of intelligibility associated with this latter effect. Speech reception thresholds were measured under headphones, using spatially separated target sentences and speech-shaped noise interferers simulated in virtual rooms. To investigate the effect of reverberation on the interferer unambiguously, the target was always anechoic. The interferer was placed in rooms with different sizes and absorptions, and at different distances and azimuths from the listener. The interaural coherence of the interferer did not fully predict the effect of reverberation. The azimuth separation of the sources and the coloration introduced by the room also had to be taken into account. The binaural effects were modeled by computing the binaural masking level differences in the studied configurations, the monaural effects were predicted from the excitation pattern of the noises, and speech intelligibility index weightings were applied to both. These parameters were all calculated from the room impulse responses convolved with noise. A 0.95–0.97 correlation was obtained between the speech reception thresholds and their predicted value.
Biotechnology: Delivering on the Promise
Authors: Greenwood James C.
Published: January 2010

Policy-makers can play an important role in bolstering the biotechnology industry.
Antisense Gets a Grip on miR-122 in Chimpanzees
Authors: Branch Andrea D. , Rice Charles M.
Published: January 2010

Hepatitis C virus–infected chimpanzees were treated with an antisense RNA that binds to and blocks the function of a microRNA that enhances viral replication without causing major side effects.
No Muss, No Fuss: Easy Protein Structure-Function Analysis
Authors: Kelner Katrina L.
Published: January 2010

Bioinformatic analysis of a bacterial protein sequence can help to identify protein regions essential for infection, which may present good drug targets.
Quantifying effects of accidents by fuzzy-logic- and simulation-based analysis
Authors: Lee Sangyoub , Halpin Daniel W , Chang Hoon
Published: January 2010

This study quantifies the effects of accidents by defining one of the indirect costs, the productive time lost owing to accidents in utility trenching operations. The probability of accidents, estimated by fuzzy-logic-based analysis of the performance of the factors (training, supervision, and preplanning) affecting safety in utility trenching operations, was used to quantify, based on simulation analysis, the productivity loss due to process delays resulting from accidents during excavation and pipe installation. It was determined that the productivity loss resulting from accidents during excavation is greater than that resulting from accidents during pipe installation. During excavation, the "very poor" condition of preplanning is most critical to productivity loss due to accidents, whereas during pipe installation, the condition of training and supervision affects the productivity loss more than that of preplanning. This paper provides insights into the relationship between the condition of the safety factors and the possible productivity loss by concomitant probability of accidents to quantify the effects of the accidents.Key words: effect of accidents, probability of accidents, productivity, fuzzy logic, simulation.
Parametric finite element analysis of a glass fibre reinforced polymer (GFRP) deck-to-girder connection for bridges
Authors: Park Ki-Tae , Kim Sang-Hyo , Kim Hyeong-Yeol , Kim Sun-Myung
Published: January 2010

This paper presents a new method for deck-to-girder connections of glass fibre reinforced polymer (GFRP) bridge decks. To design the connection system, a GFRP deck in a rectangular cross-sectional shape is considered. The size of the shear bolts, bolt location, bolt spacing, and the size and type of stiffening plate are the variables considered in the design. The behavior of the proposed deck-to-girder connection system was analysed using commercial finite element analysis software. The failure of the connection system was checked by the Tsai–Hill criterion. Effective deck-to-girder connection details for GFRP bridge decks are identified and presented based on the results of the analysis.Key words: bridge decks, glass fibres, bolted connections, pultrusion.
Probabilistic assessment of urban runoff erosion potential
Authors: Harris J A , Adams B J
Published: January 2010

At the planning or screening level of urban development, analytical modeling using derived probability distribution theory is a viable alternative to continuous simulation, offering considerably less computational effort. A new set of analytical probabilistic models is developed for predicting the erosion potential of urban stormwater runoff. The marginal probability distributions for the duration of a hydrograph in which the critical channel velocity is exceeded (termed exceedance duration) are computed using derived probability distribution theory. Exceedance duration and peak channel velocity are two random variables upon which erosion potential is functionally dependent. Reasonable agreement exists between the derived marginal probability distributions for exceedance duration and continuous EPA Stormwater Management Model (SWMM) simulations at more common return periods. It is these events of lower magnitude and higher frequency that are the most significant to erosion-potential prediction. Key words: erosion, stormwater management, derived probability distribution, exceedance duration.
Post-operating performance of construction mergers and acquisitions of the United States of America
Authors: Choi Jongsoo , Harmatuck Donald
Published: January 2010

A previous study assessed stock market returns (ex ante expectations), and this study examines the actual operating performance (ex post-operating performances) of the mergers and acquisitions (M&A) observed during the past two decades (1980-2002) in the construction industry in the United States of America. Utilizing various statistical tools and longitudinal data analysis modeling techniques, three hypotheses were tested. First, the level of synergistic gains, measured as operating cash flow returns, was not improved significantly after firm integration. Second, regarding the management wealth maximization hypothesis, the size of firms dramatically increased after the integration of the firms, and the operating performance was slightly improved compared with that before the event. Research outcomes also indicated that the previous research findings concerning stock market returns on M&A were consistent with the long-term operating performance, and thus supported the market efficiency hypothesis. Lastly, M&A guidelines for the construction industry are presented based on the research outcomes from both stock market return and operating performance analysis. Key words: mergers and acquisitions, diversification strategy, operating performance.
Comparison of the cement efficiency of two type GU cements
Authors: Tumidajski P J , Fiore L , Khodabocus T , Lachemi M , Pari R
Published: January 2010

The cement efficiency or reactivity of two type GU cements sold in the southern Ontario market was studied using compressive strength measurements of concrete coupled with Abram's Law. At 28 days, it was found that there was a marked performance difference between the two cements. For example, at 28 days, the cement efficiencies were 0.0889 and 0.0953 MPa·kg 1. The difference in cement efficiency was related somewhat to cement fineness. It was observed that the 28 day mortar strengths represented a good predictor of the relative efficiencies of the cement.Key words: cement, concrete, compressive strength, reactivity, efficiency.
Inelastic seismic torsional response of simple symmetric structures
Authors: Bruneau Michel , Mahin Stephen A.
Published: January 2010

The inelastic seismic response of simple single-story structures, symmetric in plan in the elastic domain but having lateral load resisting structural elements (LLRSEs) of unequal yield strengths, has been studied. When yielding is initiated in such structures, an instantaneous state of torsional coupling in plan induces an additional torsional component to the response of the system. This torsional effect produces, under some circumstances, a magnification of the ductility demand of the LLRSE having lesser strength as compared to what would otherwise be expected of a single-degree-of-freedom. A parametric study has been conducted to investigate the circumstances where this amplification becomes significant, and the results of this research are presented herein. The rotational inertia is shown to have a significant influence on this transient state of inelastic torsional response. A limited investigation of single-story multi-element structures, single-story structures with complex force–displacement relationships, and simple multistory structures demonstrates that the findings and observations noted from the parametric study are equally applicable to more elaborate structures. Implications on Canadian design practice are discussed. Key words: seismic response, torsional coupling, structural symmetry, inelastic response, ductility demand, parametric study, code implications, rotational inertia.
Snow on two-level flat roofs — measured vs. 1990 NBC loads
Authors: Taylor Donald A.
Published: January 2010

Between 1967 and 1982, depths and specific gravities of snow were recorded on 44 single- and multi-level flat-roofed buildings between Halifax and Edmonton. The average density of snow in the drifts where the roofs change elevation was about 3.0 kN/m3, the value used consequently in the 1990 National Building Code of Canada (NBC). This is some 25% higher than the value used in the 1985 NBC. Data on drift geometry and maximum loads in the drifts are presented and compared with provisions in the 1990 NBC. As well, the paper presents measured values of average and maximum roof-to-ground load ratios for upper level roofs and for lower roofs away from the drifts. These compare favourably with those recommended in the 1985 and 1990 NBC. The statistical variabilities of snow loads and densities are given, since these are required to establish load factors used for limit states design in the NBC. Further research needs are identified. Key words: snow loads, snow drifts, uniform snow, flat roofs, snow density, snow load variability, snow load survey.
Study of the hydraulic regime of the St. Lawrence River between Montreal and the city of Québec
Authors: Robert S. , Plotte D. , Rassam J.-C. , Boivin R. , Larivière R. , Hausser R.
Published: January 2010

This paper presents the results of a numerical model study of the St. Lawrence River flow from the Beauharnois–Les Cèdres and Carillon hydroelectric complexes, just upstream from the Montreal Archipelago, to the city of Québec. The main factors affecting the water levels in the river under free water surface conditions, and their degree of influence, were estimated. In particular, the effects of the flows, local inflows, flow variations, and tide on the water levels along the St. Lawrence maritime channel were analyzed. The daily average flows are of utmost importance, other parameters being adjusting factors. Key words: St. Lawrence River, water level prediction, numerical model.
Multi-objective process optimization for construction
Authors: Chang Peter , Bernold Leonhard
Published: January 2010

Much of the existing work in construction analysis focuses on determining the construction cost based on an allowable project duration. In this type of construction analysis, two important questions are not considered. First, is the construction cost minimized for the allowable process duration? Second, would a small change in the process duration result in a significant change in the cost of the project? An optimization method is proposed to answer these questions. The approach consists of an integration of computer simulation with goal programming. The optimization method proposed allows one to assign priorities to the various design objectives such as cost and duration, which avoids the need to use subjective weights. Furthermore, since the approach simulates the construction process by computer, it can be applied to any repetitive construction process. In addition to the capability of the model to provide a single optimal solution to a construction optimization problem, it can be used to determine the trade-off between conflicting objectives. Examples are presented to illustrate the formulation process and the capabilities as a decision-making tool for construction. It is shown that the trade-off curves produced by the proposed model can provide useful information on the cost implications of various design variables, as well as on the trade-offs that exist among them. Key words: construction optimization, multi-objective optimization, goal programming, trade-off analysis, simulation.
The Chignecto ship railway: a 19th century engineering innovation
Authors: Ircha M. C.
Published: January 2010

Just over a century ago, work commenced on the Chignecto Marine Transport Railway across the Isthmus of Chignecto. The ship railway involved the use of a hydraulic lift to raise large ships on a wheeled cradle. The cradle and the ship were to be towed across the Isthmus by two locomotives and then hydraulically lowered into the receiving waters. The project would transfer ships quicker and be less expensive than building a canal. A private company built the ship railway with the promise of an operating subsidy from the federal government. Financial problems brought the work to a standstill in August 1891. Despite what appeared to be a temporary setback, international economic and national political events prevented completion of the project. Today, the remains of the railbed, an arch culvert, and the foundations of the pump house are all that are left of this 19th century engineering innovation.The contemporary technical literature detailed many of the engineering feats at Chignecto. In 1891, Henry Ketchum, the New Brunswick engineer responsible for the concept and design, presented two concurrent papers on the ship railway to the Canadian Society of Civil Engineers. This paper documents the development of Chignecto Marine Transport Railway. Key words: history, civil engineering, Canadian, shipping, canals, marine railway, and politics.
Application of Kriging to surface water level estimation
Authors: Zrinji Zolt , Burn Donald H.
Published: January 2010

The Kriging technique is used as the interpolation component of a surface water level estimation system applicable to the estimation of the water surface profile and the associated average water level for a large lake or reservoir. The estimation system is applied to the problem of determining the average surface water elevation of Lake Winnipeg, a large multipurpose lake located in central Manitoba, Canada. The Kriging system is demonstrated to produce daily average water level estimates that are not only comparable to the results from two existing techniques but are also available earlier, in a real-time context. Additional information obtained from the basic estimation system, which can assist in identifying inconsistent input data sources, are also discussed. Key words: lake level estimation, Kriging, spatial interpolation.
Strength and efficiency of braced timber columns
Authors: Dyer D. B. Van
Published: January 2010

A rational procedure for determining the strength of braced timber columns is presented. The theoretical development takes into account the effects of interlayer slip, a phenomenon characteristic of systems with nonrigid connections. Forty-five braced wood columns were fabricated and tested. Very good agreement was observed between experimental results and theoretical predictions. As a measure of efficiency, the braced column results are compared with equivalent layered and equivalent solid systems. Key words: buckling, columns, nails, braced columns, structural engineering, nonrigid connections, timber construction, wood columns, layered, solid.
Seismic shear demand of ductile cantilever walls: a Canadian code perspective
Authors: Filiatrault André , D'Aronco Danilo , Tinawi René
Published: January 2010

During severe earthquakes, ductile flexural walls are expected to exhibit inelastic flexural behaviour while other brittle deformation mechanisms, such as shear, should remain elastic. The philosophy of the Canadian seismic provisions for flexural walls is based on the assumption that the force reduction factor is applicable to both flexure and shear. If the bending moments are limited because of the flexural strength of a wall, then the shear forces are considered to be limited by the same ratio. Recent case studies have not confirmed this philosophy. Brittle shear failures in walls are still possible even if their shear strengths are established by the Canadian standards. This paper presents an analytical investigation on the shear demand of ductile flexural walls designed for three different seismic zones in Canada. For each zone, an ensemble of code compatible historical earthquake ground motions is identified. The shear demand of each structure, under each earthquake record, is obtained by nonlinear time-history dynamic analyses. In 77% of the cases, the computed dynamic shear demand is higher than the current code shear strength. To address this issue, a force modification factor for shear, different from the one for flexure, is suggested for the Canadian code. Key words: earthquake, seismic response, shear walls.
An overview of a simulation study of the Highway 401 freeway traffic management system
Authors: Hellinga Bruce , Van Aerde Michel
Published: January 2010

This paper discusses the application of the network traffic simulation model INTEGRATION to a 35-km section of Highway 401 in Toronto, Canada. Results for the eastbound direction from 4 a.m. to 12 noon are presented. Existing freeway conditions are quantified using data from the COMPASS freeway traffic management system and from a floating car travel time survey. Variations that exist in observed link flows and trip travel durations over time of day and day of week are examined. The extent to which COMPASS data meets the data requirements of the INTEGRATION model is examined. Since the current COMPASS system encompassed less than 50% of the network analyzed, complications arise in accurately estimating the prevailing time-varying origin–destination demands, as well as in comprehensively validating the simulation model's results. The present level of model calibration results in a correlation coefficient of estimated and observed link flows of 97.23%. This level of discrepancy is generally within the natural day-to-day variations that are inherent within the system. However, travel times estimated by the simulation model tend to be underestimated, particularly for the express lanes. Further model calibration, to improve the model's results, is deferred until more of the network is covered by COMPASS. Key words: traffic simulation, COMPASS, model calibration, model validation, speed–flow relationship.
Modélisation hydrodynamique du lac Saint-Pierre, fleuve Saint-Laurent : l'influence de la végétation aquatique
Authors: Boudreau Paul , Leclerc Michel , Fortin Guy R.
Published: January 2010

The macrophytes (aquatic plants) can have a substantial effect on the hydrodynamics of some watercourses. A mathematical formulation for the resistance effect of macrophytes on the current is inserted in a two-dimensional finite element hydrodynamic model. The method introduced herein allows to take into account the morphology, the density, and the growth curve of the different species of macrophytes present in the river. The Lake Saint-Pierre between Sorel and Trois-Rivières (Québec, Canada) in the St. Lawrence River is used to demonstrate the approach. The mathematical aspect of the model is first briefly presented. The field surveys of macrophytes and some other data sets used with the model are then analyzed. Finally, after the calibration–validation step, which insures the good behavior of the model, some results are presented to show the effect of the macrophytes on the flow structure. Key words: hydrodynamics, aquatic plants, St. Lawrence River, Lake Saint-Pierre, two-dimensional modelling, simulation, finite element method, Manning's coefficient.
Engineering creativity — doctum ingenium
Authors: Navin Francis P. D.
Published: January 2010

Creativity is the prerogative of humans. Human creativity uses what already exists and changes it in unpredictable ways that bring about a desired enlargement of human experience that goes beyond the usual choices. The creative process has been well documented and a number of methods have been developed to assist individuals to generate ideas. Methods such as brainstorming, synectics, or more systematic morphological approaches are available. The key elements of all the methods are to prepare your mind and to postpone evaluation for as long as possible to increase the number of ideas.The actual number of useful creative ideas appears to be quite limited and can be shown to be increasing at an exponential rate. Civil engineers need to participate in this increasing creativity. The profession and universities need to adopt policies and practices that encourage creative and divergent thinking at the solution generation phase of problem solving. To actually accomplish this, civil engineering will require that the teaching methods used in disciplines such as art and architecture be investigated and the useful parts incorporated in the profession. Key words: creativity, innovation, ideas, brainstorming, synectics.
CHAOTIC SYNCHRONIZATION OF FRACTIONAL-ORDER MODIFIED COUPLED DYNAMOS SYSTEM
Authors: WANG XINGYUAN , HE YIJIE
Published: January 2010

This paper studies the problem of chaotic synchronization of the fractional-order modified coupled dynamos system, designs the activate controllers, and then proves that the self-synchronization of the fractional-order modified coupled dynamos system and the fractional-order modified coupled dynamos system's different structure synchronization with the fractional-order Lorenz system can both arrive theoretically. The simulation results demonstrate the validity of the activate controller.
OPTICAL PROPERTIES OF MOLECULAR SYSTEM COUPLED TO THE SOLVENT
Authors: ROMERO-DEPABLOS A. , PAZ J. L. , MENDOZA-GARCÍA A. , MARTÍN P. , CASTRO E.
Published: January 2010

Analytic approximations for the absorption coefficient and refraction index have been obtained for a two-level molecular system in the presence of a four-wave mixing signal. Stochastic collisions among solute–solvent molecules produce a broadening of the upper level of energy. In this work, we have used four generalized Lorentzian approximants of the Voigt function as probability distribution, calculated by the two-point quasi-rational approximant method previously denoted as asymptotical Padé technique, for the evaluation of the average values of the Fourier components associated to the induced coherences. The innovation of this type of distributions allows us, by taking appropriate limits, to find similar profiles of optical properties as those using Gaussian and Lorentzian distribution functions.
TELEPORTATION CAPABILITY OF FOUR-QUBIT CLUSTER STATE IN ONE-VERSUS-THREE OR THREE-VERSUS-ONE QUBIT DISTRIBUTION
Authors: GAO HUA-MIN , LIU YI-MIN , LI MING-LING , LIU XIAN-SONG , ZHANG ZHAN-JUN
Published: January 2010

The capability of a one-dimensional four-qubit cluster state for teleportation is extensively investigated in the condition that the four qubits are non-averagely distributed between two locations. Because of the inherent qubit orientation of the cluster state, we found that only in eight distributions can an arbitrary single-qubit state be perfectly teleported from a sender to a receiver. For each case, the necessary local operations and classical communication (LOCC) are explicitly shown.
QUANTUM STATE TRANSFER THROUGH A QUBIT NETWORK WITH ENERGY SHIFTS AND FLUCTUATIONS
Authors: CASACCINO ANDREA , LLOYD SETH , MANCINI STEFANO , SEVERINI SIMONE
Published: January 2010

We study quantum state transfer through a qubit network modeled by spins with XY interaction, when relying on a single excitation. We show that it is possible to achieve perfect transfer by shifting (adding) energy to specific vertices. This technique appears to be a potentially powerful tool for changing, and in some cases improving, the transfer capabilities of quantum networks. Analytical results are presented for all-to-all networks and for all-to-all networks with a missing link. Moreover, we evaluate the effect of random fluctuations on the transmission fidelity.
Synthesis and photobiological properties of novel silicon(IV) phthalocyanines axially modified by paracetamol and 4-hydroxyphenylacetamide
Authors: Huang Jian-Dong , Jiang Xiong-Jie , Shen Xiao-Min , Tang Qing-Qing
Published: January 2010

Two novel axial-disubstituted silicon(IV) phthalocyanines (compounds 1 and 2) have been prepared by introducing paracetamol (a common antipyretic analgesic) or its isomer 4-hydroxyphenylacetamide at the axial positions of silicon(IV) phthalocyanine, respectively. Their photophysical and biological properties have been examined. Both compounds are highly soluble and exhibit very similar absorption spectra in N, N-dimethylformamide, which is typical for non-aggregated phthalocyanines. Both compounds are photocytotoxic against HT29 human colon adenocarcinoma cells. Compound 2 shows a very high in vitro photodynamic activity, with the IC50 value down to 15 nM. In contrast, compound 1 exhibits a much lower in vitro photodynamic activity toward HT29 cells, which can be attributed to its higher aggregating trend in the biological medium and lower singlet oxygen quantum yield.
BALANCED WORDS AND MAJORIZATION
Authors: JENKINSON OLIVER
Published: January 2010

When expressed in terms of base-2 expanions, balanced words are majorized by other words of the same slope. Consequently they have smaller standard deviation and larger geometric mean than all words with given arithmetic mean (or slope), they can be expressed as a doubly stochastic average of any such word, and they can be derived from any such word by a finite number of transfers.
ON SUPER f-EDGE COVER-COLORING IN MULTIGRAPHS
Authors: XU CHANGQING , LIU GUIZHEN
Published: January 2010

Given a multigraph G, an edge cover-coloring of G is called an f-edge cover-coloring, if each color appears at each vertex v at least f(v) times. Let [Formula: see text] be the maximum positive integer k for which an f-edge cover-coloring with k colors of G exists. An f-edge cover-coloring of G is called a super f-edge cover-coloring, if parallel edges receive distinct colors. Let [Formula: see text] denote the maximum positive integer k for which a super f-edge cover-coloring with k colors of G exists. A sufficient condition for a graph G to have [Formula: see text] is given.
Tonically Discharging Genioglossus Motor Units Show No Evidence of Rate Coding With Hypercapnia
Authors: Richardson Patrick A. , Bailey E. Fiona
Published: January 2010

The genioglossus (GG) is considered the principle protrudor muscle of the human tongue. Unlike most skeletal muscles, GG electromyographic (EMG) activities are robustly preserved in sleep and thus may fulfill a critical role in preserving airway patency. Previous studies in human subjects also confirm that the GG EMG increases in response to chemoreceptor and mechanoreceptor stimulation. This increase occurs secondary to the recruitment of previously inactive motor units (MUs) and/or an increase in firing rate of already active MUs. Which strategy the nervous system uses when the synaptic drive onto GG motoneurons increases is not known. Here we report on GG whole muscle and tonic MU activities under conditions that mimic sleep, i.e., mild-moderate elevations in CO2 (3% inspired CO2 or the addition of a 1.0 l dead space) and elevated airway resistance. Based on previous work in rat, we hypothesized that mild hypercapnia would increase the firing rates of tonic MUs and that these effects would be further potentiated by a modest increase in airway resistance. Fine wire and tungsten microelectrodes were inserted into the GG to record whole muscle and single MU activities in 21 subjects (13 women, 8 men; 20–55 yr). Either 3% inspired CO2 or added dead space resulted in a 200–300% increase in the amplitude of both tonic and phasic components of the whole muscle GG EMG and a doubling of minute ventilation. Despite these changes, recordings obtained from a total of 84 tonically discharging GG single MUs provide no evidence of a change in firing rate under any of the conditions. On this basis we conclude that in healthy adults, the increase in the tonic component of the whole muscle GG EMG secondary to mild hypercapnia is due almost exclusively to the recruitment of previously inactive MUs.
Neocortex Network Activation and Deactivation States Controlled by the Thalamus
Authors: Hirata Akio , Castro-Alamancos Manuel A.
Published: January 2010

Neocortex network activity varies from a desynchronized or activated state typical of arousal to a synchronized or deactivated state typical of quiescence. Such changes are usually attributed to the effects of neuromodulators released in the neocortex by nonspecific activating systems originating in basal forebrain and brain stem reticular formation. As a result, the only role attributed to thalamocortical cells projecting to primary sensory areas, such as barrel cortex, is to transmit sensory information. However, thalamocortical cells can undergo significant changes in spontaneous tonic firing as a function of state, although the role of such variations is unknown. Here we show that the tonic firing level of thalamocortical cells, produced by cholinergic and noradrenergic stimulation of the somatosensory thalamus in urethane-anesthetized rats, controls neocortex activation and deactivation. Thus in addition to its well-known role in the relay of sensory information, the thalamus can control the state of neocortex activation, which may complement the established roles in this regard of basal forebrain and brain stem nuclei. Because of the topographical organization of primary thalamocortical pathways, this mechanism provides a means by which area-specific neocortical activation can occur, which may be useful for modality-specific sensory processing or selective attention.
Significance of Tribocorrosion in Biomedical Applications: Overview and Current Status
Authors: Mathew M. T. , Srinivasa Pai P. , Pourzal R. , Fischer A. , Wimmer M. A.
Published: January 2010

Recently, “tribocorrosion,” a research area combining the science of tribology and corrosion, has drawn attention from scientists and engineers belonging to a wide spectrum of research domains. This is due to its practical impact on daily life and also the accompanying economical burdens. It encompasses numerous applications including the offshore, space, and biomedical industry, for instance, in the case of artificial joints (Total Hip Replacement, THR) in orthopedic surgery, where implant metals are constantly exposed to tribological events (joint articulations) in the presence of corrosive solutions, that is, body fluids. Keeping the importance of this upcoming area of research in biomedical applications in mind, it was thought to consolidate the work in this area with some fundamental aspects so that a comprehensive picture of the current state of knowledge can be depicted. Complexity of tribocorrosion processes has been highlighted, as it is influenced by several parameters (mechanical and corrosion) and also due to the lack of an integrated/efficient test system. Finally a review of the recent work in the area of biotribocorrosion is provided, by focusing on orthopedic surgery and dentistry.
Optimal Control Systems by Time‐Dependent Coefficients Using CAS Wavelets
Authors: Abualrub Taher , Sadek Ibrahim , Abukhaled Marwan
Published: January 2010

This paper considers the problem of controlling the solution of an initial boundary‐value problem for a wave equation with time‐dependent sound speed. The control problem is to determine the optimal sound speed function which damps the vibration of the system by minimizing a given energy performance measure. The minimization of the energy performance measure over sound speed is subjected to the equation of motion of the system with imposed initial and boundary conditions. Using the modal space technique, the optimal control of distributed parameter systems is simplified into the optimal control of bilinear time‐invariant lumped‐parameter systems. A wavelet‐based method for evaluating the modal optimal control and trajectory of the bilinear system is proposed. The method employs finite CAS wavelets to approximate modal control and state variables. Numerical examples are presented to demonstrate the effectiveness of the method in reducing the energy of the system.
Parallel Processor for 3D Recovery from Optical Flow
Authors: Barron-Zambrano Jose Hugo , Martin del Campo-Ramirez Fernando , Arias-Estrada Miguel
Published: January 2010

3D recovery from motion has received a major effort in computer vision systems in the recent years. The main problem lies in the number of operations and memory accesses to be performed by the majority of the existing techniques when translated to hardware or software implementations. This paper proposes a parallel processor for 3D recovery from
optical flow. Its main feature is the maximum reuse of data and the low number of clock cycles to calculate the optical
flow, along with the precision with which 3D recovery is achieved. The results of the proposed architecture as well
as those from processor synthesis are presented.
Neurophenomenology
Authors: Peters Frederic H.
Published: January 2010

Although the subject matter of religious studies is essentially phenomenal (e.g., conscious acts, attitudes, intentions, worldviews), the analysis of the basic datum, consciousness itself, remains of necessity incomplete because of the discipline's restriction to the phenomenal envelope. Philosophical and psychological analysis contributed to our understanding of consciousness, but, lacking access to the neurological engine-room of consciousness, their explanatory power is compromised as well. Neuroscience, on the other hand, has moved beyond the behaviorist denial of consciousness and recent research indicates that the evolutionary development of the brain's representational capacity may well account for its ability to generate consciousness. These advances provide an opportunity to marry objective explanation with phenomenological descriptions of the view from the inside, creating a powerful new analytic tool: Neuro-phenomenology. Comprised of an exaggerated differentiation between conscious state and informational content, and constituting an important phenomenological category within many Hindu and Buddhist programs, lucid consciousness makes an ideal subject with which to assess the analytic power of Neurophenomenology.