bluuebunny/crossref_metadata_2025 huggingface dataset:
Maximum Displacement Variability of Stochastic Structures Subject to Deterministic Earthquake Loading
Authors: Graham L.L.
Published: January 2014

The variability of the maximum response displacement of random frame structures under deterministic earthquake loading are examined in this paper using stochastic finite element techniques. The elastic modulus and the mass density are assumed to be described by cross‐correlated stochastic fields. Specifically, a variability response function formulation is used for this problem, which allows for calculation of spectral‐distribution‐free upper bounds of the maximum displacement variance. Further, under the assumption of prespecified correlation functions describing the spatial variation of the material properties, variability response functions are used to calculate the corresponding maximum displacement variance. Two numerical examples are provided to demonstrate the methodology. Results show that randomness in the material properties can lead to significant uncertainty in the maximum response displacement.
An Exploratory Study of the Relationship between Face Recognition Memory and the Volume of Medial Temporal Lobe Structures in Healthy Young Males
Authors: Mackay Clare E. , Roberts Neil , Mayes Andrew R. , Downes John J. , Foster Jonathan K. , Mann David
Published: January 2014

A rigorous new methodology was applied to the study of structure function relationships in the living human brain. Face recognition memory (FRM) and other cognitive measures were made in 29 healthy young male subjects (mean age = 21.7 years) and related to volumetric measurements of their cerebral hemispheres and of structures in their medial temporal lobes, obtained using the Cavalieri method in combination with high resolution Magnetic Resonance Imaging (MRI. Greatest proportional variability in volumes was found for the lateral ventricles (57%) for the cerebral hemispheres (8%) in the mean volumes of the hippocampus, parahippocampal gyrus, amygdala, caudate nucleus, temporal pole and temporal lobe on the right and left sides of the brain. The volumes of the right and left parahippocampal gyrus, temporal pole, temporal lobe, and left hippocampus were, prior to application of the Bonferroni correction to take account of 12 multiple comparisons, significantly correlated with the volume of the corresponding hemisphere (p < 0.05). The volumes of all structures were highly correlated (p < 0.0002 for all comparisons) between the two cerebral hemispheres. There were no positive relationships between structure volumes and FRM score. However, the volume of the right amygdala was, prior to application of the Bonferroni correction to take account of 38~multiple comparisons, found to be significantly smaller in the five most consistent high scorers compared to the five most consistent low scorers (t = 2.77, p = 0.025). The implications for possible relationships between healthy medial temporal lobe structures and memory are discussed.
Underwater Shock Response Analysis of a Floating Vessel
Authors: van Aanhold J.E. , Meijer G.J. , Lemmen P.P.M.
Published: January 2014

The response of a surface vessel to underwater shock has been calculated using an explicit finite element analysis. The analysis model is two‐dimensional and contains the floating steel structure, a large surrounding water volume and the free surface. The underwater shock is applied in the form of a plane shock wave and cavitation is considered in the analysis. Advanced computer graphics, in particular video animations, provide a powerful and indispensable means for the presentation and evaluation of the analysis results.
Fixed Points of Two‐Degree of Freedom Systems
Authors: Abu-Hilal Mohammed
Published: January 2014

The presence of fixed points in a frequency response of vibrating systems can greatly complicate the vibration reduction if these points are not recognized. In this paper, the fixed points of two‐degree of freedom systems are studied. The frequencies at which fixed points occur and their amplitudes are determined analytically.

In this paper, the fixed points of two‐degree of freedom systems are studied. The frequencies at which fixed points occur and their amplitudes are determined analytically.
Optical Measurement of Cable and String Vibration
Authors: Achkire Y. , Preumont A.
Published: January 2014

This paper describes a non contacting measurement technique for the transverse vibration of small cables and strings using an analog position sensing detector. On the one hand, the sensor is used to monitor the cable vibrations of a small scale mock‐up of a cable structure in order to validate the nonlinear cable dynamics model. On the other hand, the optical sensor is used to evaluate the performance of an active tendon control algorithm with guaranteed stability properties. It is demonstrated experimentally, that a force feedback control law based on a collocated force sensor measuring the tension in the cable is feasible and provides active damping in the cable.
Directed Attention in Gilles de la Tourette Syndrome
Authors: Georgiou Nellie , Bradshaw John L. , Phillips Jim G.
Published: January 2014

Gilles de la Tourette syndrome (TS) is a basal ganglia (BG) disorder, associated not only with hyperkinetic movements but also with attentional impairments. This experiment sought to ascertain whether overt direct visual attention would influence tactile attentional performance in TS, via the use of a vibrotactile choice reaction time procedure involving biased probabilities of event occurrence. Participants were required to look (i.e., direct gaze) either at the hand receiving the most (expected) vibrations, or the hand less often stimulated (the unexpected), for both crossed and uncrossed arm postures. Contrary to our predictions, gaze did not influence attentional performance in TS patients. Furthermore, patients were found not to be sensitive to distributions of event probability; that is, they did not demonstrate normal expectancy effects like controls. Attentional deficits in TS (as in Parkinson’s disease, another BG disorder) may pertain more to difficulties in holding rather than in shifting the focus of attention. Moreover, directing attention towards the unexpected locus in the crossed arm posture improved overall performance in both patients and controls, suggesting that increased task demands (e.g., crossed arm posture), and/or unexpected stimulus location, may be alleviated by directed attention. These impairments may stem from dysfunction in the circuits linking the frontal lobes with the BG.
A Variant of the Kleine‐Levin Syndrome following Head Trauma
Authors: Kostic V. S. , Stefanova E. , Svetel M. , Kozic D.
Published: January 2014

A 19‐year‐old man developed the Kleine‐Levin syndrome three weeks after the head trauma and subsequent neurosurgical evacuation of right‐sided, fronto‐temporal epidural hematoma. The expression of periodic episodes was observed for hypersomnolence and, to a lesser degree, for behavioral disturbances, while the hyperphagia was constantly present during a period of 1.5 years. These clinical features were associated with the focal, right‐sided hypothalamic lesion and ipsilateral posttraumatic parenchymal temporal lobe damage on NMR imaging.
Identification of Unknown, Time‐Varying Forces/Moments in Dynamics and Vibration Problems Using a New Approach To Deconvolution
Authors: Johnson C.D.
Published: January 2014

In this paper an alternative approach to the classical deconvolution idea is used to obtain a new and practical method for real‐time identification of unknown, time‐varying forces/moments in a general class of linear (linearized) dynamics and vibration problems with multiple‐inputs and multiple‐measurements. This new method for force/moment identification is unique in the respect that the uncertainty in the force/moment time‐variations is not characterized by random‐process methods, but rather by a generalized spline‐model with totally unknown weighting coefficients and completely known basis‐functions. The basis‐functions are custom chosen in each application to reflect, qualitatively, the known characteristics of the force/moment time‐variations to be identified. The method does not involve explicit identification of the unknown weighting coefficients. General‐purpose identification algorithms for both continuous‐time and discrete‐time measurements are developed, and a worked example including computer simulation results is presented.
Quasi‐Resonance Effects Observed in The 1994 Northridge Earthquake, and Others
Authors: Fischer Edward G. , Fischer Thomas P.
Published: January 2014

Sine‐beat phenomena have been found in the 1994 Northridge earthquake records, and they are capable of producing time‐history responses and damaging quasi‐resonance effects in structures. Linear, single DOF (degree of freedom) oscillators, in lieu of nonlinear, multiple DOF systems, have been found adequate to discuss the failures of tall circuit breakers during the 1971 San Fernando and the 1989 Loma Prieta quakes in California. The use of sine‐beat excitation for seismic‐shaking‐table tests of equipment continues to be a conservative simulation of earthquakes.
The Opercular‐Subopercular Syndrome: Four Cases with Review of the Literature
Authors: Bakar M. , Kirshner H. S. , Niaz F.
Published: January 2014

We present four cases of the ‘opercular syndrome’ of volitional paresis of the facial, lingual, and laryngeal muscles (bilateral facio‐glosso‐pharyngo‐masticatory paresis). Case histories and CT brain images are presented, along with a review of the literature concerning this long‐recognized but little‐known syndrome. The neuroanatomic basis of the syndrome classically involves bilateral lesions of the frontal operculum. We propose, on the basis of our cases and others, that the identical syndrome can arise from lesions of the corticobulbar tracts, not involving the cortical operculum. Our cases included one with bilateral subcortical lesions, one with a unilateral left opercular lesion and a possible, non‐visualized right hemisphere lesion, one with unilateral cortical and unilateral subcortical pathology, and one with bilateral cortical lesions. These lesion localizations suggest that any combination of cortical or subcortical lesions of the operculum or its connections on both sides of the brain can produce a syndrome indistinguishable from the classical opercular syndrome. We propose the new term ‘opercular‐subopercular syndrome’ to encompass cases with predominantly or partially subcortical lesions.
Magnetic Damping For Maglev
Authors: Zhu S. , Cai Y. , Rote D.M. , Chen S.S.
Published: January 2014

Magnetic damping is one of the important parameters that control the response and stability of maglev systems. An experimental study to measure magnetic damping directly is presented. A plate attached to a permanent magnet levitated on a rotating drum was tested to investigate the effect of various parameters, such as conductivity, gap, excitation frequency, and oscillation amplitude, on magnetic damping. The experimental technique is capable of measuring all of the magnetic damping coefficients, some of which cannot be measured indirectly.
Random Amplitude Fatigue Life of Electroformed Nickel Micro‐Channel Heat Exchanger Coupons
Authors: Byrd Larry , Camden Michael P. , Maddux Gene E. , Simmons Larry W.
Published: January 2014

The use of micro‐channel heat exchangers (MCHEX) with coolant flow passage diameters less than 1 mm has been proposed for heat flux, weight, or volume limited environments. This paper presents room temperature, random amplitude, ε − N (strain versus number of cycles to failure) curves for MCHEX coupons formed by electroplating nickel on a suitable form. These coupons are unique in two aspects; the microstructure formed by electroplating and the presence of holes as an integral part of the structure. The hole diameters range from approximately 10% to 50% to the specimen thickness. The fatigue life of electroformed nickel can be estimated from constant amplitude data using the formulation presented. The heat exchangers with channels parallel to the coupon direction have a lower fatigue life than the solid material.
Evaluation of Accelerometer Mechanical Filters on Submerged Cylinders Near an Underwater Explosion
Authors: Yiannakopoulos G. , van der Schaaf P.J.
Published: January 2014

An accelerometer, mounted to a structure near an explosion to measure elasto‐plastic deformation, can be excited at its resonant frequency by impulsive stresses transmitted within the structure. This results in spurious high peak acceleration levels that can be much higher than acceleration levels from the explosion itself. The spurious signals also have higher frequencies than the underlying signal from the explosion and can be removed by a low pass filter. This report assesses the performance of four accelerometer and filter assemblies. The assessment involves measurements of the response of a mild steel cylinder to an underwater explosion, in which each assembly is mounted onto the interior surface of the cylinder. Three assemblies utilise a piezoresistive accelerometer in which isolation is provided mechanically. In the fourth assembly, a piezoelectric accelerometer, with a built‐in filter, incorporates both mechanical and electronic filtering. This assembly is found to be more suitable because of its secure mounting arrangement, ease of use, robustness and noise free results.
On The Vibration of a Cracked Rotating Blade
Authors: Wu Ming-Chuan , Huang Shyh-Chin
Published: January 2014

The dynamic behavior of a rotating blade containing a transverse crack was investigated. First, the local flexibility of the cracked blade was obtained by using the method of the released energy. An energy principle, in conjunction with a weighted residual method, was then applied to yield the discrete equations of motion. The equations of motion were further utilized to study the influences of the crack depth and location on the bending natural frequencies under various of rotation speeds. The numerical calculation showed that the crack effects the natural frequencies and the response appreciably only if it is relatively deep and locates near the root of the blade. However, the effects increase exponentially with the depth increases. In addition to the natural frequencies, the displacement responses of the blade with a crack under a constant lateral forces were discussed as well. This was done by calculating the deflections at the tip of the blade for various crack depths and locations. Similar to the rotation speed of the blade frequency, the deflection was offset by the increase of the rotation. However, the centrifugal effects increased significantly such that the crack’s effects became relatively insignificant. Nevertheless, the study showed that the changes on the natural frequency and the tip‐deflection of the blade due to a crack may be used as indices for on‐line detection of cracks.
Active Suspension of Truck Seat
Authors: Kawana Masaaki , Shimogo Taro
Published: January 2014

The driver’s seat of a heavy duty truck is usually mounted on a spring–damper assembly anchored to the cab floor. To improve riding comfort, this study investigated the effects of mounting a computer‐controlled actuator in parallel with the traditional spring–damper assembly. A dynamic model of the seat is represented by a two degree‐of‐freedom system, including a cushion. In this paper, a control system is designed, using optimal control theory, which minimizes rms vertical acceleration at a point representing the driver’s hip point. In this system, accelerations of the hip point, the seat frame and the cab floor are picked up and integrated to obtain the state variables to be fed back and fed forward to the actuator through a digital computer. The actuator is constructed with electric servo‐motor and ball‐screw mechanism. The experimental study was carried out on a shaker, which simulates the vibrations of the cab floor in actual service. Results were obtained for both a dummy and a real human body. The vibration test produced rms accelerations of the seat and the hip point of about 1.0 m/s2 without the actuator, while the rms accelerations were suppressed to about 0.5 m/s2 at a rms input voltage to the servo‐motor of 1.0 V.
Emotional Processing following Cortical and Subcortical Brain Damage: Contribution of the Fronto‐Striatal Circuitry
Authors: Breitenstein Caterina , Daum Irene , Ackermann Hermann
Published: January 2014

The present study examined the differential contribution of cortical and subcortical brain structures in emotional processing by comparing patients with focal cortical lesions (n = 32) to those with primarily subcortical dysregulation of the basal ganglia (Parkinson’s disease n = 14). A standardized measure of emotional perception (Tübingen Affect Battery) was used. Only patients in the more advanced stages of Parkinson’s disease and patients with focal damage to the (right) frontal lobe differed significantly from controls in both facial expression and affective prosody recognition. The findings imply involvement of the fronto‐striatal circuitry in emotional processing.
Damage Occurrence under Dynamic Loading For Anisotropic Strain Rate Sensitive Materials
Authors: Lauro F. , Bennani B. , Oudin J. , Ni X.
Published: January 2014

A damage model is integrated into the explicit finite element framework to predict the damage evolution which occurrs under dynamic loading in the crash or stamping process. This damage model is based on the description of the growth, nucleation and coalescence of the microvoids. The microvoid growth is related to the plastic incompressibility equation. The microvoid nucleation is controlled by either the plastic strain or stress. The microvoid coalescence is described by a specific function. This damage process leads to the progressive loss of the structure stress carrying capacity. The ductile fracture occurs once it has vanished. The model is adapted to take the material behaviour anisotropy and damage anisotropy into account. The sensitivity of the damage evolution under dynamic loadings in the case of porous strain rate sensitive material is analysed using single tensile tests. Static and dynamic tensile tests of a notched specimen are performed. Influences of the strain rate and the shape of specimen on the failure mode and loss of the structure’s stress carrying capacity are shown.
Collisions of Constrained Rigid Body Systems with Friction
Authors: Shen Haijun , Townsend Miles A.
Published: January 2014

A new approach is developed for the general collision problem of two rigid body systems with constraints (e.g., articulated systems, such as massy linkages) in which the relative tangential velocity at the point of contact and the associated friction force can change direction during the collision. This is beyond the framework of conventional methods, which can give significant and very obvious errors for this problem, and both extends and consolidates recent work. A new parameterization and theory characterize if, when and how the relative tangential velocity changes direction during contact. Elastic and dissipative phenomena and different values for static and kinetic friction coefficients are included. The method is based on the explicitly physical analysis of events at the point of contact. Using this method, Example 1 resolves (and corrects) a paradox (in the literature) of the collision of a double pendulum with the ground. The method fundamentally subsumes other recent models and the collision of rigid bodies; it yields the same results as conventional methods when they would apply (Example 2). The new method reformulates and extends recent approaches in a completely physical context.
‘Pure’ Constructional Apraxia—A Cognitive Analysis of a Single Case
Authors: Trojano Luigi , Grossi Dario
Published: January 2014

We report on a patient affected by selective drawing disabilities. The patient could correctly reproduce and draw simple geometric figures on request, but when he tried to reproduce more complex drawings or to draw common objects he performed very poorly. To identify the cognitive impairment in this patient, we adopted two test batteries based on recent information‐processing models of drawing. Results showed that the patient’s drawing disabilities were independent of visuo‐perceptual and executive impairments. These findings support recent cognitive models of drawing abilities: some intermediate stages of drawing exist at which information is processed to prepare and guide motor output, and which may be selectively disrupted after discrete cerebral lesions.
Late‐Onset Startle Syndrome and Obsessive Compulsive Disorder
Authors: Gonzalez Alejandro , Philpot Michael P.
Published: January 2014

A case of late onset sporadic startle syndrome in a patient with a right posterior fossa brain tumour is reported. The exaggerated startle response did not respond to treatment with clonazepam. In addition to anxiety and depression, the patient developed obsessive‐ compulsive symptoms which responded to behavioural therapy. The possible mechanisms for this unique pattern of symptoms are discussed.
Description of Muzzle Blast by Modified Ideal Scaling Models
Authors: Fansler Kevin S.
Published: January 2014

Gun blast data from a large variety of weapons are scaled and presented for both the instantaneous energy release and the constant energy deposition rate models. For both ideal explosion models, similar amounts of data scatter occur for the peak overpressure but the instantaneous energy release model correlated the impulse data significantly better, particularly for the region in front of the gun. Two parameters that characterize gun blast are used in conjunction with the ideal scaling models to improve the data correlation. The gun‐emptying parameter works particularly well with the instantaneous energy release model to improve data correlation. In particular, the impulse, especially in the forward direction of the gun, is correlated significantly better using the instantaneous energy release model coupled with the use of the gun‐emptying parameter. The use of the Mach disc location parameter improves the correlation only marginally. A predictive model is obtained from the modified instantaneous energy release correlation.
Review: Rotor Balancing
Authors: Foiles W.C. , Allaire P. E. , Gunter E. J.
Published: January 2014

This article reviews the literature concerning the balancing of rotors including the origins of various balancing techniques including ones that use influence coefficient, modal, unified, no phase, and no amplitude methods to balance. This survey covers the computational algorithms as well as the physical concepts involved in balancing rotating equipment.
Sleep Paralysis and Hallucinosis
Authors: Stores Gregory
Published: January 2014

Background: Sleep paralysis is one of the many conditions of which visual hallucinations can be a part but has received relatively little attention. It can be associated with other dramatic symptoms of a psychotic nature likely to cause diagnostic uncertainty. Methods and results: These points are illustrated by the case of a young man with a severe bipolar affective disorder who independently developed terrifying visual, auditory and somatic hallucinatory episodes at sleep onset, associated with a sense of evil influence and presence. The episodes were not obviously related to his psychiatric disorder. Past diagnoses included nightmares and night terrors. Review provided no convincing evidence of various other sleep disorders nor physical conditions in which hallucinatory experiences can occur. A diagnosis of predormital isolated sleep paralysis was made and appropriate treatment recommended. Conclusions: Sleep paralysis, common in the general population, can be associated with dramatic auxiliary symptoms suggestive of a psychotic state. Less common forms are either part of the narcolepsy syndrome or (rarely) they are familial in type. Interestingly, sleep paralysis (especially breathing difficulty) features prominently in the folklore of various countries.
Investigation of Subcombination Internal Resonances in Cantilever Beams
Authors: Arafat Haider N. , Nayfeh Ali H.
Published: January 2014

Activation of subcombination internal resonances in transversely excited cantilever beams is investigated. The effect of geometric and inertia nonlinearities, which are cubic in the governing equation of motion, is considered. The method of time‐averaged Lagrangian and virtual work is used to determine six nonlinear ordinary‐differential equations governing the amplitudes and phases of the three interacting modes. Frequency‐ and force‐response curves are generated for the case ω ≈ ω4 ≈ 1/2(ω2 + ω5). There are two possible responses: single‐mode and three‐mode responses. The single‐mode periodic response is found to undergo supercritical and subcritical pitchfork bifurcations, which result in three‐mode interactions. In the case of three‐mode responses, there are conditions where the low‐frequency mode dominates the response, resulting in high‐amplitude quasiperiodic oscillations.
Spherical Solutions of an Underwater Explosion Bubble
Authors: Wardlaw Andrew B. , Mair Hans U.
Published: January 2014

The evolution of the 1D explosion bubble flow field out to the first bubble minimum is examined in detail using four different models. The most detailed is based on the Euler equations and accounts for the internal bubble fluid motion, while the simplest links a potential water solution to a stationary, Isentropic bubble model. Comparison of the different models with experimental data provides insight into the influence of compressibility and internal bubble dynamics on the behavior of the explosion bubble.
A Consistent Dynamic Finite Element Formulation For a Pipe Using Euler Parameters
Authors: Arabyan Ara , Jiang Yaqun
Published: January 2014

A pipe element developed earlier for the analysis of combined large bending and torsional deformations of blood vessels under static loading is extended to model behavior in the presence of large rotations and time‐varying external forces. As in the case of the earlier element, the enhanced element supports ovalization and warping of its cross‐section. The enhancements presented in this paper are comprised of a mass matrix and gyroscopic effects resulting from fast rotation rates and large deformations. The effectiveness of the element is demonstrated by two examples, which simulate the three‐dimensional behavior of a highly flexible pipe under dynamic loading conditions.
Electric Source Localization Adds Evidence for Task‐Specific CNVs
Authors: Tarkka Ina M. , Basile Luis F. H.
Published: January 2014

This study was an attempt to replicate recent magnetoencephalographic (MEG) findings on human task‐specific CNV sources (Basile et al., Electroencephalography and Clinical Neurophysiology 90, 1994, 157–165) by means of a spatio‐temporal electric source localization method (Scherg and von Cramon, Electroencephalography and Clinical Neurophysiology 62, 1985, 32–44; Scherg and von Cramon, Electroencephalography and Clinical Neurophysiology 65, 1986, 344‐360; Scherg and Berg, Brain Electric Source Analysis Handbook, Version 2). The previous MEG results showed CNV sources in the prefrontal cortex of the two hemispheres for two tasks used, namely visual pattern recognition and visual spatial recognition tasks. In the right hemisphere, the sources were more anterior and inferior for the spatial recognition task than for the pattern recognition task. In the present study we obtained CNVs in five subjects during two tasks identical to the MEG study. The elicited electric potentials were modeled with four spatio‐temporal dipoles for each task, three of which accounted for the visual evoked response and one that accounted for the CNV. For all subjects the dipole explaining the CNV was always localized in the frontal region of the head, however, the dipole obtained during the visual spatial recognition task was more anterior than the one obtained during the pattern recognition task. Thus, task‐specific CNV sources were again observed, although the stable model consisted of only one dipole located close to the midline instead of one dipole in each hemisphere. This was a major difference in the CNV sources between the previous MEG and the present electric source analysis results. We discuss the possible basis for the difference between the two methods used to study slow brain activity that is believed to originate from extended cortical patches.
Localizing Energy Sources and Sinks in Plates Using Power Flow Maps Computed From Laser Vibrometer Measurements
Authors: Arruda J.R.F. , Mas P.
Published: January 2014

This paper presents an experimental method especially adapted for the computation of structural power flow using spatially dense vibration data measured with scanning laser Doppler vibrometers. In the proposed method, the operational deflection shapes measured over the surface of the structure are curve‐fitted using a two‐dimensional discrete Fourier series approximation that minimizes the effects of spatial leakage. From the wavenumber‐frequency domain data thus obtained, the spatial derivatives that are necessary to determine the structural power flow are easily computed. Divergence plots are then obtained from the computed intensity fields. An example consisting of a rectangular aluminum plate supported by rubber mounts and excited by a point force is used to appraise the proposed method. The proposed method is compared with more traditional finite difference methods. The proposed method was the only to allow the localization of the energy source and sinks from the experimental divergence plots.
Obsessive‐Compulsive Disorder in the Elderly
Authors: Philpot Michael P. , Banerjee Sube
Published: January 2014

Four cases of obsessive‐compulsive disorder arising in late life in association with a presumed organic aetiology are described. Three of the four had brief episodes of OCD earlier in their lives. Neuropsychological assessment demonstrated impairments in verbal fluency and visuo‐spatial tasks. No case exhibited global intellectual impairment. The two patients who complied with appropriate treatment became asymptomatic after 4–6 months.
Modeling Mitigation Effects of Watershield on Shock Waves
Authors: Shin Y.S. , Lee M. , Lam K.Y. , Yeo K.S.
Published: January 2014

The object of this analysis is to investigate mitigation effects of watershield on air blast waves. To examine the water mitigation concept, features of the free‐field detonation process are studied from a series of one‐dimensional simulations using a multimaterial Eulerian finite element technique. Five different shock Hugoniots for water are compared, and the most accurate data are suggested. To verify the numerical procedure, results are compared with available experimental data for UNDEX problem and analytical predictions for air shocks. For the case of contact watershield, the magnitude of peak pressure generally decreases and the shock arrival time increases with increasing thickness of watershield. The total pressure impulse is reduced significantly at near field. Non‐contact watershield was also examined, and was found to provide a better design criterion based on the further decay of peak pressure.
Fractal Two‐Level Finite Element Method For Free Vibration of Cracked Beams
Authors: Leung A.Y.T. , Su R.K.L.
Published: January 2014

The fractal two‐level finite element method is extended to the free vibration behavior of cracked beams for various end boundary conditions. A cracked beam is separated into its singular and regular regions. Within the singular region, infinite number of finite elements are virturally generated by fractal geometry to model the singular behavior of the crack tip. The corresponding numerous degrees of freedom are reduced to a small set of generalized displacements by fractal transformation technique. The solution time and computer storage can be remarkably reduced without sacrifying accuracy. The resonant frequencies and mode shapes computed compared well with the results from a commercial program.
Paroxysmal Compulsion to Handle Keys in a Computer Operator Due To Meningioma in the Left Supplementary Motor Area
Authors: Tei H. , Iwata M. , Miura Y.
Published: January 2014

We describe the case of a computer operator who experienced paroxysmal attacks several times in which she felt a compulsion to handle keys with her right hand or actually her right hand moved involuntarily in a key‐handling rhythm. Cranial CT and MRI revealed a mass lesion in the left medial aspect of the frontal lobe (supplementary motor area). After the removal of this tumor (meningioma), there were no more paroxysmal attacks. We suggest that voluntary movements controlled by the supplementary motor area were deranged by seizures provoked by the tumor. This case is attractive in relation to obsessive‐compulsive disorder.
Ground Motion and Air Overpressure Study
Authors: Sharp Michael K. , Yule Donald E.
Published: January 2014

A seismic attenuation and air overpressure study was conducted to determine the attenuation of explosion induced ground motions and air overpressures as a function of distance from shallow subsurface detonated charges, and to derive parameters to predict blast effects at distances beyond the ordinance disposal facility boundary. A total of 210 explosive shots were monitored producing 2048 time histories of ground motions recorded in the vertical, radial, and transverse directions, in addition to recording air overpressures. The data were analyzed for peak particle velocities and peak air overpressures, then plotted versus scaled range. A best fit line was determined for the data to give average, 95% non‐exceedance, and upper bound predictive equations which can be used in the disposal operations to avoid damage to adjacent structures.
Effects of Boundary Conditions on the Parametric Resonance of Cylindrical Shells under Axial Loading
Authors: Ng T.Y. , Lam K.Y.
Published: January 2014

In this paper, a formulation for the dynamic stability analysis of circular cylindrical shells under axial compression with various boundary conditions is presented. The present study uses Love’s first approximation theory for thin shells and the characteristic beam functions as approximate axial modal functions. Applying the Ritz procedure to the Lagrangian energy expression yields a system of Mathieu–Hill equations the stability of which is analyzed using Bolotin’s method. The present study examines the effects of different boundary conditions on the parametric response of homogeneous isotropic cylindrical shells for various transverse modes and length parameters.
Coupling of Flexural and Longitudinal Damped Vibration in a Two‐Layered Beam
Authors: Pourroy F. , Shakhesi S. , Trompette P.
Published: January 2014

In dynamics, the effect of varying the constitutive materials’ thickness of a two‐layered beam is investigated. Resonance frequencies and damping variations are determined. It is shown that for specific thicknesses the coupling of longitudinal and flexural vibrations influences the global modal damping ratio significantly.
Wave Dispersion and Attenuation in Viscoelastic Split Hopkinson Pressure Bar
Authors: Cheng Z.Q. , Crandall J.R. , Pilkey W.D.
Published: January 2014

A viscoelastic split Hopkinson pressure bar intended for testing soft materials with low acoustic impedance is studied. Using one‐dimensional linear viscoelastic wave propagation theory, the basic equations have been established for the determination of the stress—strain—strain rate relationship for the tested material. A method, based on the spectral analysis of wave motion and using measured wave signals along the split Hopkinson pressure bar, is developed for the correction of the dispersion and attenuation of viscoelastic waves. Computational simulations are performed to show the feasibility of the method.
Unusual Visual Symptoms and Ganser‐Like State Due To Cerebral Injury: A Case Study Using 18F‐Deoxyglucose Positron Emission Tomography
Authors: Snyder Stephen L. , Buchsbaum Monte S. , Krishna R. C.
Published: January 2014

Bizarre visual symptoms and absurd verbal responses to questions, in a 32‐year‐old man recovering from a severe asthma episode, suggested a possible conversion disorder with Ganser‐like symptoms. Positron Emission Tomography (PET)revealed bilateral lesions involving occipital association cortex and posterior temporal and parietal lobes, most likely infarcts from hypoxia. PET permitted correlation of the patient’s specific cortical lesions with his unusual perceptual, cognitive, and speech symptoms, including Ganser‐like state , to a degree not previously possible in such cases.
Determination of Dynamic Stress in Fibre Reinforced Materials under Impact Load
Authors: Müller D.H. , Franz Th. , Tenzler A.
Published: January 2014

The investigations reported in this paper are intended to obtain knowledge about stress concentrations within fibre reinforced plastics due to impact loadings below the damage threshold of the anisotropic material. The paper focuses on presenting the application of a dynamic photoelastic technique more than on providing extensive and detailed experimental data. Thus, a brief summary of the experimental part is given. The potential value of the developed experimental method is demonstrated exemplary for an arbitrary composite.
Surface Ship Shock Modeling and Simulation: Two‐Dimensional Analysis
Authors: Shin Young S. , Santiago Leonard D.
Published: January 2014

The modeling and simulation of the response of a surface ship system to underwater explosion requires an understanding of many different subject areas. These include the process of underwater explosion events, shock wave propagation, explosion gas bubble behavior and bubble‐pulse loading, bulk and local cavitation, free surface effect, fluid‐structure interaction, and structural dynamics. This paper investigates the effects of fluid‐structure interaction and cavitation on the response of a surface ship using USA‐NASTRAN‐CFA code. First, the one‐dimensional Bleich‐Sandler model is used to validate the approach, and second, the underwater shock response of a two‐dimensional mid‐section model of a surface ship is predicted with a surrounding fluid model using a constitutive equation of a bilinear fluid which does not allow transmission of negative pressures.
Significance of Operating Environment in Condition Monitoring of Large Civil Structures
Authors: Alampalli Sreenivas
Published: January 2014

Success of remote long‐term condition monitoring of large civil structures and developing calibrated analytical models for damage detection, depend significantly on establishing accurate baseline signatures and their sensitivity. Most studies reported in the literature concentrated on the effect of structural damage on modal parameters without emphasis on reliability of modal parameters. Thus, a field bridge structure was studied for the significance of operating conditions in relation to baseline signatures. Results indicate that in practice, civil structures should be monitored for at least one full cycle of in‐service environmental changes before establishing baselines for condition monitoring or calibrating finite‐element models. Boundary conditions deserve special attention.
Limiting Performance of Helmets for the Prevention of Head Injury
Authors: Cheng Z.Q. , Pilkey W.D. , Crandall J.R. , Bass C.R. , Darvish K.
Published: January 2014

This is a study of the theoretical optimal (limiting) performance of helmets for the prevention of head injury. A rigid head injury model and a two‐mass translational head injury model are employed. Several head injury criteria are utilized, including head acceleration, the head injury criterion (HIC), the energy imparted to the brain which is related to brain injury, and the power developed in the skull that is associated with skull fracture. A helmeted head hitting a rigid surface and a helmeted head hit by a moving object such as a ball are considered. The optimal characteristics of helmets and the impact responses of the helmeted head are investigated computationally. An experiment is conducted on an ensemble of bicycle helmets. Computational results are compared with the experimental results.
Effects of Two‐Year Treatment with the Cholinesterase Inhibitor Rivastigmine on Behavioural Symptoms in Alzheimer’s Disease
Authors: Rösler Michael , Retz Wolfgang , Retz-Junginger P. , Dennler Hans Joachim
Published: January 2014

Alzheimer’s disease (AD) is accompanied by prominent behavioural disturbances. They cause significant distress for both caregivers and patients and can play a major role in the decision to institutionalise AD patients. Recent evidence suggests that cholinergic deficiencies not only contribute to the memory and cognitive abnormalities of AD but are also responsible for some behavioural abnormalities seen over the course of the disease. In this study we assessed the ability of rivastigmine, a pseudo‐irreversible cholinesterase inhibitor, to improve behavioural and psychopathologic symptoms in AD. The analysis included 34 patients present in the Germanarm of the international study B303 who received and completed long‐term treatment with rivastigmine in the open‐label study B305. Assessments of behaviour and psychopathological symptoms were performed using the behavioural component of the Clinicians Interview Based Impression of Change Plus (CIBIC‐Plus). Results show that long‐term treatment with rivastigmine can slow the progression of behavioural and psychopathological symptoms of AD. Behavioural symptoms showing stabilisation included aggressiveness, activity disturbances, hallucinations and paranoid features. Results also suggest that patients treated earlier with rivastigmine may attain a greater benefit compared with patients whose treatment is delayed 6 months. Further studies examining the effects of rivastigmine on behavioural disturbances in AD are therefore warranted.
Finite Element Computational Dynamics of Rotating Systems
Authors: Mackerle Jaroslav
Published: January 2014

This bibliography lists references to papers, conference proceedings and theses/dissertations dealing with finite element analysis of rotor dynamics problems that were published in 1994–1998. It contains 319 citations. Also included, as separate subsections, are finite element analyses of rotor elements – discs, shafts, spindles, and blades. Topics dealing with fracture mechanics, contact and stability problems of rotating machinery are also considered in specific sections. The last part of the bibliography presents papers dealing with specific industrial applications.
The De‐Noising of Sonic Echo Test Data through Wavelet Transform Reconstruction
Authors: Watson J.N. , Addison P.S. , Sibbald A.
Published: January 2014

This paper presents the results of feasibility study into the application of the wavelet transform signal processing method to sonic based non‐destructive testing techniques. Finite element generated data from cast in situ foundation piles were collated and processed using both continuous and discrete wavelet transform techniques. Results were compared with conventional Fourier based methods. The discrete Daubechies wavelets and the continuous Mexican hat wavelet were used and their relative merits investigated. It was found that both the continuous Mexican hat and discrete Daubechies D8 wavelets were significantly better at locating the pile toe compared than the Fourier filtered case. The wavelet transform method was then applied to field test data and found to be successful in facilitating the detection of the pile toe.
Differential Contribution of Right and Left Amygdala to Affective Information Processing
Authors: Markowitsch Hans J.
Published: January 2014

Evidence for a differential involvement of the human left and right amygdala in emotional and cognitive behaviour is reviewed, with a particular emphasis on functional imaging results and case reports on patients with amygdalar damage. The available evidence allows one to conclude that there is definitely a hemisphere specific processing difference between the left and right amygdala. However, between studies the direction of the asymmetry is partly incongruent. In spite of this, the following tentative proposals are made: the left amygdala is more closely related to affective information encoding with a higher affinity to language and to detailed feature extraction, and the right amygdala to affective information retrieval with a higher affinity to pictorial or image‐related material. Furthermore, the right amygdala may be more strongly engaged than the left one in a fast, shallow or gross analysis of affect‐related information.
Guidance Preconditioning by an Impulse Sequence for Robust Residual Vibration Suppression
Authors: Antoniadis I.
Published: January 2014

In order to suppress residual vibrations, a general method is presented for preconditioning any guidance function prior to its application to a dynamic system, by convolving it with a sequence of impulses. The approach includes first the development of the necessary design specifications for the impulse sequence, so that the robustness properties cover the widest possible variation of the system natural frequencies. Three solution methods are proposed then, with special emphasis in the achievement of the minimum possible duration time of the impulse sequence. Numerical experiments verify the effectiveness of the robustness, not only with respect to variations of the natural frequency, but also with respect to variations of a range of other linear and non‐linear variables.
Storage and Processing Working Memory Functions in Alzheimer‐Type Dementia
Authors: Vecchi T. , Saveriano V. , Paciaroni L.
Published: January 2014

A selective deterioration of working memory functions has been suggested as an explanation of the cognitive decay occurring in normal ageing as well as in Alzheimer‐type dementia. Recent studies have highlighted that elderly people’s limitations in working memory functions may be better interpreted when analysing the specific characteristics of the cognitive process (i.e., passive storage or active manipulation of information). In the present study, we have adapted a procedure used to investigate age‐related memory modifications, involving both verbal and visuo‐spatial material in tasks tapping passive and active processes, to investigate the deterioration associated with Alzheimer′s disease. A group of Alzheimer patients in the early stages of the disease were matched to a control group of healthy elderly. Results show that Alzheimer patients performed less accurately than the control group in all tasks. However, the deficit was maximised in the case of active processes, regardless of the type of material used (verbal or visuo‐spatial). These data highlight the importance of considering the amount of active processing as the key variable when interpreting the decay in cognitive functions in the early stages of Alzheimer’s disease.
Efficient Transient Analysis for Large Locally Nonlinear Structures
Authors: Gordis Joshua H. , Radwick Jeffrey
Published: January 2014

A general and exact theory for transient structural synthesis is extended to address structural systems with an arbitrary number of localized sources of structural dynamic nonlinearity. The formulation is independent of model size, in that only those model degrees‐of‐freedom of interest need be retained in the synthesis. The theory provides for the efficient calculation of nonlinear transient response due to externally applied loads and prescribed base motions. The theory can function as a substructure coupling and structural modification procedure allowing structural nonlinearities to be isolated from the remaining linear substructures, which are solved once. The nonlinear synthesis in effect installs the nonlinear elements and calculates the nonlinear transient response. An example demonstrate the order of magnitude decrease in time required, as compared to traditional direct integration.