bluuebunny/crossref_metadata_2025 huggingface dataset:
Analytical Predictions of Fragment Penetration through Hollow Concrete Masonry Units
Authors: Bogosian David , Gerber Bence
Published: January 2014

Modeling steel casing fragment impacts on hollow CMU poses some problems, since the fragments will typically penetrate through the front face and may also penetrate the back face. Techniques are needed for predicting (a) the size of the hole created by the penetration, (b) the size of the annular region of damaged concrete around the hole, and (c) the residual velocity of the fragment. A series of calculations using the AUTODYN code were performed to investigate the accuracy and reliability of the model. The model uses the smooth particle hydrodynamics (SPH) approach to represent the CMU. A variety of steel fragment sizes were projected at a layer of CMU, and the resulting hole size, damage, and fragment residual velocity were tabulated. Results were validated against existing empirical relationships to insure the model′s applicability, while additional analyses demonstrated trends and parametric sensitivity.
False Memories of Emotional and Neutral Words
Authors: Sharkawy Jennifer El , Groth Katarina , Vetter Céline , Beraldi Anna , Fast Kristina
Published: January 2014

This study used the Deese‐Roediger‐McDermott paradigm [34] to investigate the direction and the extent to which emotional valence in semantic word lists influences the formation of false memories (FM). The experimental paradigm consisted of 1) a study phase (learning of neutral and negative lists of words semantically associated to a non‐presented critical lure (CL), 2) a free recall phase, and 3) a recognition phase. Participants had to indicate whether the displayed item was "new" (new item or non‐studied CL) or “old” (studied list item). CL associated with negative word lists elicited significantly more FM than CL associated with neutral word lists. This finding is in contrast to previous work showing that emotional words elicit fewer FM than neutral words. The results of our study also suggest that valence is capable of influencing emotional memory in terms of encoding and retrieval processes.
Energy Flow Boundary Element Method for Vibration Analysis of One and Two Dimension Structures
Authors: Lee Ho-Won , Hong Suk-Yoon , Park Do-Hyun , Kwon Hyun-Wung
Published: January 2014

In this paper, Energy Flow Boundary Element Method (EFBEM) was developed to predict the vibration behavior of one‐ and two‐dimensional structures in the medium‐to‐high frequency ranges. Free Space Green functions used in the method were obtained from EFA energy equations. Direct and indirect EFBEMs were formulated for both one‐ and two‐dimensional cases, and numerically applied to predict the energy density and intensity distributions of simple Euler‐Bernoulli beams, single rectangular thin plates, and L‐shaped thin plates vibrating in the medium‐to‐high frequency ranges. The results from these methods were compared with the EFA solutions to verify the EFBEM.
Modal and Path Contribution Models from In‐Operation Data: Review and New Approaches
Authors: Van der Auweraer H. , Mas P. , Peeters P. , Janssens K. , Vecchio A.
Published: January 2014

In several cases, laboratory‐based modelling approaches such as Experimental Modal Analysis and Transfer Path Analysis run into limitations with respect to technical and economical feasibility (accessibility of the structure, excitation feasibility, measurement time, accuracy, …) as well as model representativity. Therefore, approaches such as in‐operation modal analysis (OMA) have been developed and are reaching a similar degree of acceptability as standard EMA, with all limitations regarding accuracy and observability of the structural dynamics. In the same line of reasoning fits the question of system characterization and identification using (or based on) other operation data types such as transmissibility functions and coherence functions and data analysis procedures such as principal component analysis. Using these testing and analysis paradigms instead of the classical load‐FRF‐response one, key analysis techniques such as transfer path and contribution analysis can be reconsidered.
Etiology of Frontal Network Syndromes in Isolated Subtentorial Stroke
Authors: Hoffmann Michael , Cases Lourdes Benes
Published: January 2014

Background:The neurobiology of the frontal network syndrome (FNS) that may occur with isolated subtentorial stroke is unknown.

Aim:Evaluate for frontal network syndromes in young people post subtentorial stroke who have recovered neurologically and compare to a stroke lesion group least likely to manifest frontal network syndromes.

Methods:Young people (18–49 years) with isolated cerebellar or brainstem subtentorial stroke (ST) that had recovered to independency (Rankin score ࣘ 2) with minimal or no residual neurological deficit (NIHSS ࣘ 4) with neurological recovery enabling resumption of former employment. Comparison was made to age and education matched young people with posterior circulation territory parieto occipital lobe infarcts (PO). Depression, anxiety, systemic disease, autoimmune disease, neurodegenerative disease and substance abuse were specific exclusions. A battery of frontal tests surveying the principal frontal network syndromes (apathy, disinhibition, executive dysfunction, emotional intelligence quotient) was used. Neurological deficit and long tract signs were measured by the NIH stroke score (NIHSS).

Results:From the cognitive stroke registry of young stroke patients (n= 511), analysis for isolated subtentorial infarction yielded cerebellar infarcts (n= 43, 8.4%) and brainstem infarcts (n= 36, 7.0%). After exclusions, 16 patients (cerebellum,n= 10, pons,n= 6) were compared to 10 PO infarct patients controlled for mean age, gender and NIH stroke scores. Overall 11/16 (69%) patients in the ST and 5/10 (50%) in the PO group manifested one or more of the principal FNS syndromes. Mean T scores for apathy, disinhibition, executive function and emotional intelligence standard scores were significantly more impaired in the ST group, but not for WCST error percentage scores.

Conclusions:The mismatch of scant neurological deficit manifested by low NIHSS but with FNS in the majority of isolated ST stroke and more so than with PO stroke, gives support for a state dependent or neurotransmitter perturbation. The clinical impact is that such syndromes may be amenable to neuropharmacological intervention.
On the Convergence of Nonlinear Modes of a Finite Element Model
Authors: Balagangadhar Ramesh , Slater Joseph C.
Published: January 2014

Convergence of finite element models is generally realized via observation of mesh independence. In linear systems invariance of linear modes to further mesh refinement is often used to assess mesh independence. These linear models are, however, often coupled with nonlinear elements such as CFD models, nonlinear control systems, or joint dynamics. The introduction of a single nonlinear element can significantly alter the degree of mesh refinement necessary for sufficient model accuracy. Application of nonlinear modal analysis [1,2] illustrates that using linear modal convergence as a measure of mesh quality in the presence of nonlinearities is inadequate. The convergence of the nonlinear normal modes of a simply supported beam modeled using finite elements is examined. A comparison is made to the solution of Boivin, Pierre, and Shaw [3]. Both methods suffer from the need for convergence in power series approximations. However, the finite element modeling method introduces the additional concern of mesh independence, even when the meshing the linear part of the model unless p‐type elements are used [4]. The importance of moving to a finite element approach for nonlinear modal analysis is the ability to solve problems of a more complex geometry for which no closed form solution exists. This case study demonstrates that a finite element model solution converges nearly as well as a continuous solution, and presents rough guidelines for the number of expansion terms and elements needed for various levels of solution accuracy. It also demonstrates that modal convergence occurs significantly more slowly in the nonlinear model than in the corresponding linear model. This illustrates that convergence of linear modes may be an inadequate measure of mesh independence when even a small part of a model is nonlinear.
Vibration Isolation for Parallel Hydraulic Hybrid Vehicles
Authors: Nguyen The M. , Elahinia Mohammad H.
Published: January 2014

In recent decades, several types of hybrid vehicles have been developed in order to improve the fuel economy and to reduce the pollution. Hybrid electric vehicles (HEV) have shown a significant improvement in fuel efficiency for small and medium‐sized passenger vehicles and SUVs. HEV has several limitations when applied to heavy vehicles; one is that larger vehicles demand more power, which requires significantly larger battery capacities. As an alternative solution, hydraulic hybrid technology has been found effective for heavy duty vehicle because of its high power density. The mechanical batteries used in hydraulic hybrid vehicles (HHV) can be charged and discharged remarkably faster than chemical batteries. This feature is essential for heavy vehicle hybridization. One of the main problems that should be solved for the successful commercialization of HHV is the excessive noise and vibration involving with the hydraulic systems. This study focuses on using magnetorheological (MR) technology to reduce the noise and vibration transmissibility from the hydraulic system to the vehicle body. In order to study the noise and vibration of HHV, a hydraulic hybrid subsystem in parallel design is analyzed. This research shows that the MR elements play an important role in reducing the transmitted noise and vibration to the vehicle body. Additionally, locations and orientations of the isolation system also affect the efficiency of the noise and vibration mitigation. In simulations, a skyhook control algorithm is used to achieve the highest possible effectiveness of the MR isolation system.
Experimental Investigation of the Dynamic Response of Squeeze Film Dampers Made of Steel and Glass/Epoxy
Authors: Faris Waleed F. , Khalid Asad A. , Albagul A. , Ismail Godem A.
Published: January 2014

This work is devoted to the fabrication and investigation of the Squeeze Film Dampers (SFDs) which are widely used in many applications. This include the fabrication of a test rig and several dampers with different sizes and two different materials which composite and non‐composite. Composite dampers (Glass/epoxy), each consists of 30 layers, were fabricated by hand lay‐up method. Outer and inner diameters of all the fabricated dampers were maintained as 60 and 40 mm respectively. Non‐composite dampers (Steel) were fabricated and tested using turning machine. Three dampers of different lengths were examined for both materials. A rotor‐bearing system for the analysis has been designed and fabricated. The test rig consists of mild steel shaft, two supports, oil pressure system, and two self‐alignment ball bearings were fixed on each end support. Two squeeze film dampers were used for the two support ends. Vibration amplitude has been examined for all the fabricated dampers at different shaft rotational speeds. The first resonance speed was examined for all the dampers tested. Results show that the vibration amplitude of the steel damper was lower than Glass/epoxy dampers with the same L/D ratio. On the other hand, a considerable weight saving has been achieved by using Glass/epoxy composite dampers. It has been found that the performance of squeeze film damper improved with increasing length/diameter ratio (L/D) within the range tested.
Application of Lanczos and Schur Vectors in Structural Dynamics
Authors: Radeş M.
Published: January 2014

The paper explains the advantages of using Lanczos/Schur vectors when performing dynamic analyses of very large models: faster computation of low spectrum eigenproperties, reduced computer storage requirements, increased robustness of test‐analysis models, and sensor location by the effective independence method without solving large size eigenproblems.
On the Influence of Welding Residual Stresses on the Dynamic Behavior of Structures
Authors: Bezerra A.C. , Vieira L.C. , Rade D.A. , Scotti A.
Published: January 2014

It is widely known that welding processes induce the generation of residual stresses, which, through the so‐named stress stiffening effect, can influence the static and dynamic behavior of the welded components. Thus, accounting for this influence becomes important for the understanding of experimental observations and accurate modeling of the dynamic behavior. In this study, the numerical and experimental characterization of the influence of welding residual stresses on the flexural dynamic characteristics of rectangular plates is addressed. It is suggested a general modeling methodology based on finite elements comprising three subsequent analyses, namely: a thermal analysis to compute the transient temperature history due to welding thermal loading; a structural analysis accounting for plastic strains to obtain the welding residual stress fields and geometric distortions, and a dynamic analysis to compute the dynamic characteristics taking into account the stress‐stiffening effect and geometric distortions. The results demonstrate the importance of considering the influence of welding residual stresses in the prediction of the flexural dynamic behavior of plates and the feasibility and efficiency of the simplified modeling approach, which can readily be extended to more complex situations, for characterizing this influence.
Assessment of Behavioural Markers of Autonoetic Consciousness during Episodic Autobiographical Memory Retrieval: A Preliminary Analysis
Authors: Irish M. , Lawlor B. A. , O′Mara S. M. , Coen R. F.
Published: January 2014

There is ongoing theoretical debate regarding episodic memory and how it can be accurately measured, in particular if the focus should be content‐based recall of episodic details or something more experiential involving the subjective capacity to mentally travel back in time and “re‐live” aspects of the original event. The autonoetic subscale of the Episodic Autobiographical Memory Interview (EAMI) is presented here as a new test instrument that attempts to redress theoretical and methodological shortcomings in autobiographical memory assessment. The EAMI merges a phenomenological detail‐based approach with an assessment of autonoetic consciousness, departing considerably from traditional Remember/Know paradigms used within this field. We present findings from an initial pilot study investigating the potential markers of autonoetic consciousness that may accompany episodic retrieval. Key behavioural indices of autonoetic consciousness, notably those of viewer perspective, visual imagery, and emotional re‐experiencing, emerged as being inextricably bound with the level of phenomenological detail recalled and the overall re‐living judgment. The autonoetic subscale of the EAMI permits conceptually refined assessment of episodic personal memories and the accompanying subjective experience of mental re‐living, characteristic of episodic memory.
Structural Parameter Identification of Fixed End Beams by Inverse Method Using Measured Natural Frequencies
Authors: Türker T. , Bayraktar A.
Published: January 2014

Structural parameter identification based on the measured dynamic responses has become very popular recently. This paper presents structural parameter identification of fixed end beams by inverse method using measured natural frequencies. An added mass is used as a modification tool. The measurements of the flexural vibrations of a fixed end beam with and without added mass are performed by using experimental modal testing. The solution of free bending transverse vibration of the beam is obtained by solving the differential equation motion of Bernoulli‐Euler beam. By introducing the natural frequencies from experimental measurements into the solution of differential equation, the structural parameters of the fixed end beam are calculated.

It is seen from the results that the values of the mass distribution and elasticity modulus identified using the first natural frequency of the beam nearly close to the real values. Besides, the theoretical frequencies obtained using the identified structural parameters also close to the measured frequencies.
Disrupted Auto‐Activation, Dysexecutive and Confabulating Syndrome Following Bilateral Thalamic and Right Putaminal Stroke
Authors: De Witte Lieve , Engelborghs Sebastiaan , Verhoeven Jo , De Deyn Peter P. , Mariën Peter
Published: January 2014

Objective: Clinical, neuropsychological, structural and functional neuroimaging results are reported in a patient who developed a unique combination of symptoms after a bi‐thalamic and right putaminal stroke. The symptoms consisted of dysexecutive disturbances associated with confabulating behavior and auto‐activation deficits. Background: Basal ganglia and thalamic lesions may result in a variety of motor, sensory, neuropsychological and behavioral syndromes. However, the combination of a dysexecutive syndrome complicated at the behavioral level with an auto‐activation and confabulatory syndrome has never been reported. Methods: Besides clinical and neuroradiological investigations, an extensive set of standardized neuropsychological tests was carried out. Results: In the post‐acute phase of the stroke, a dysexecutive syndrome was found in association with confabulating behavior and auto‐activation deficits. MRI showed focal destruction of both thalami and the right putamen. Quantified ECD SPECT revealed bilateral hypoperfusions in the basal ganglia and thalamus but no perfusion deficits were found at the cortical level. Conclusion: The combination of disrupted auto‐activation, dysexecutive and confabulating syndrome in a single patient following isolated subcortical damage renders this case exceptional. Although these findings do not reveal a functional disruption of the striato‐ventral pallidal‐thalamic‐frontomesial limbic circuitry, they add to the understanding of the functional role of the basal ganglia in cognitive and behavioral syndromes.
Prefrontal and Temporo‐Parietal Involvement in Taking Others’ Perspective: TMS Evidence
Authors: Costa Alberto , Torriero Sara , Oliveri Massimiliano , Caltagirone Carlo
Published: January 2014

Introduction: Understanding the mental states of others entails a number of cognitive processes known as Theory of Mind (ToM). Behavioural and functional neuroimaging evidence suggests that prefrontal and temporo‐parietal cortices are involved in these abilities. The present study was aimed at investigating the role of the dorsolateral prefrontal cortex and temporo‐parietal junction in ToM by using a repetitive transcranial magnetic stimulation (rTMS) paradigm.

Material and Methods: Eleven healthy subjects participated in the study. The experimental ToM procedure was constituted by false belief and faux‐pas written stories. Subjects were evaluated in baseline condition (Sham) and after 1Hz rTMS over the left/right dorsolateral prefrontal cortex and temporo‐parietal junction. A score for accuracy and response times were recorded.

Results: As regards false beliefs, rTMS over right prefrontal and temporo‐parietal areas significantly interfered with response times (p < 0.05). The application of rTMS over right/left prefrontal and right temporo‐parietal cortices also significantly worsened accuracy in the ability to take the others’ perspective in faux‐pas tasks as compared to Sham (p ࣘ 0.05 in all cases).

Conclusions: The results of the present study are consistent with previous findings supporting the hypothesis that prefrontal and temporo‐parietal regions are part of a neural network specifically underpinning the ability to attribute mental states to others.
Agraphia in Bulbar-Onset Amyotrophic Lateral Sclerosis: Not Merely a Consequence of Dementia or Aphasia
Authors: Ichikawa Hiroo , Takahashi Nobuyoshi , Hieda Soutaro , Ohno Hideki , Kawamura Mitsuru
Published: January 2014

The clinical significance and characteristics of writing errors in bulbar-onset amyotrophic lateral sclerosis (ALS) are not clear. We retrospectively investigated writing samples in 19 patients with bulbar-onset ALS without preceding extra-motor symptoms. Co-development of dementia and/or aphasia was also explored and single photon emission computed tomography (SPECT) images of the brain were reviewed. As a result, a high prevalence of writing errors (15 of the 19 patients) was found. Of note were isolated writing errors with neither dementia nor aphasia verified in 2 patients whose dysarthria was mild enough to evaluate spoken language. The remaining 13 patients also showed agraphia, but either dysarthria was too severe to evaluate aphasia or frontotemporal dementia (FTD)-like features co-existed. Of these patients, one who initially lacked dementia subsequently developed FTD-like features. The frequent writing errors were omission or substitution of kana letters and syntactic errors. SPECT images showed bilateral or left-side dominant hypoperfusion in the frontotemporal lobes as a consistent feature. These results show that patients with bulbar-onset ALS frequently exhibit agraphic writing errors and that these are not merely consequences of dementia or aphasia. However, these writing errors may indicate the involvement of frontotemporal language-related areas beyond the primary motor cortex.
An Inelastic Beam Element with Hysteretic Damping
Authors: Papakonstantinou K.G. , Dimizas P.C. , Koumousis V.K.
Published: January 2014

In this work, an inelastic beam macro‐element that incorporates hysteretic damping is presented. Based on classical theory of plasticity, a Bouc‐Wen type model is utilized that simulates the hysteretic behavior of an inelastic spring element. Using this model, an inelastic nonlinear beam element is formulated based on the appropriate combination of two coupled nonlinear spring elements. The equations of motion are determined and are cast in a state‐space form for the vector of the end displacements, velocities and hysteretic forces. The system is solved by employing a Runge‐Kutta type of algorithm. The proposed inelastic beam model is then employed to simulate the experimental dynamic behavior of steel beams. The model parameters are estimated with the aid of a nonlinear system identification algorithm using existing experimental data. The proposed element approximates the inelastic behavior of steel beams adequately within plastic regions that do not undergo substantial stiffness degradation, or other relevant phenomena. Finally, the hysteretic damping features of the model are demonstrated.
Clinical Application of Standardized Cognitive Assessment Using fMRI. I. Matrix Reasoning
Authors: Allen Mark D. , Fong Alina K.
Published: January 2014

Functional MRI is increasingly recognized for its potential as a powerful new tool in clinical neuropsychology. This is likely due to the fact that, with some degree of innovation, it is possible to convert practically any familiar cognitive test into one that can be performed in the MRI scanning environment. However, like any assessment approach, meaningful interpretation of fMRI data for the purpose of patient evaluation crucially requires normative data derived from a sample of unimpaired persons, against which individual patients may be compared. Currently, no such normative data are available for any fMRI-based cognitive testing protocol. In this paper, we report the first of a series of fMRI-compatible cognitive assessment protocols, a matrix reasoning test (f-MRT), for which normative samples of functional activation have been collected from unimpaired control subjects and structured in a manner that makes individual patient evaluation possible in terms of familiar z-score distributions. Practical application of the f-MRT is demonstrated via a contrastive case-study of two individuals with cognitive impairment in which fMRI data identifies subtleties in patient deficits otherwise missed by conventional measures of performance.
The Influence of a Mistuned Blade’s Staggle Angle on the Vibration and Stability of a Shaft‐Disk‐Blade Assembly
Authors: Chiu Yi-Jui , Huang Shyh-Chin
Published: January 2014

The influence on coupling vibrations and stability among shaft‐torsion, disk‐transverse and blade‐bending of a rotor system with a mistuned blade′s staggle angle was investigated analytically. A shaft‐disk‐blade system has been found existing two types of coupling vibrations, disk‐blade (DB), and blade‐blade (BB) modes when the shaft was assumed rigid. If the shaft′s torsional flexibility was taken into account, an additional type of coupling modes, shaft‐disk‐blade (SDB), appeared. When an angle‐mistuned blade existed, the blades periodicity was destroyed and it was found to change not only the natural frequencies but also the types of modes. Due to blade′s mistune, the shaft torsion had to participate to balance such that DB modes vanished and replaced by SDB modes. A mistuned staggle angle was numerically found to alter the natural frequencies in an almost linear trend. At last, the rotational effects were found to merge frequency loci and eventually reached an instability point. Very interestingly, a mistuned blade diminished the possible instability caused by blade‐dominating modes, which existed in a perfect and periodic rotor. In words, the rotor might benefit from a mistuned blade from the stability viewpoint. The shaft‐dominating mode, yet, was unaffected by the mistune and retained a possible instability.
Modeling Blast Loading on Buried Reinforced Concrete Structures with Zapotec
Authors: Bessette Greg C.
Published: January 2014

A coupled Euler‐Lagrange solution approach is used to model the response of a buried reinforced concrete structure subjected to a close‐in detonation of a high explosive charge. The coupling algorithm is discussed along with a set of benchmark calculations involving detonations in clay and sand.
A Space‐Time Finite Element Model for Design and Control Optimization of Nonlinear Dynamic Response
Authors: Moita P.P. , Cardoso J.B. , Valido A.J.
Published: January 2014

A design and control sensitivity analysis and multicriteria optimization formulation is derived for flexible mechanical systems. This formulation is implemented in an optimum design code and it is applied to the nonlinear dynamic response. By extending the spatial domain to the space‐time domain and treating the design variables as control variables that do not change with time, the design space is included in the control space. Thus, one can unify in one single formulation the problems of optimum design and optimal control. Structural dimensions as well as lumped damping and stiffness parameters plus control driven forces, are considered as decision variables. The dynamic response and its sensitivity with respect to the design and control variables are discretized via space‐time finite elements, and are integrated at‐once, as it is traditionally used for static response. The adjoint system approach is used to determine the design sensitivities. Design optimization numerical examples are performed. Nonlinear programming and optimality criteria may be used for the optimization process. A normalized weighted bound formulation is used to handle multicriteria problems.
Optimal Control of an 8‐DOF Vehicle Active Suspension System Using Kalman Observer
Authors: Sadati S. Hossein , Malekzadeh Salar , Ghasemi Masood
Published: January 2014

In this paper, an 8‐DOF model including driver seat dynamics, subjected to random road disturbances is used in order to investigate the advantage of active over conventional passive suspension system. Force actuators are mounted parallel to the body suspensions and the driver seat suspension. An optimal control approach is taken in the active suspension used in the vehicle. The performance index for the optimal control design is a quantification of both ride comfort and road handling. To simulate the real road profile condition, stochastic inputs are applied. Due to practical limitations, not all the states of the system required for the state‐feedback controller are measurable, and hence must be estimated with an observer. In this paper, to have the best estimation, an optimal Kalman observer is used. The simulation results indicate that an optimal observer‐based controller causes both excellent ride comfort and road handling characteristics.
Design and Control of Nonlinear Mechanical Systems for Minimum Time
Authors: Cardoso J.B. , Moita P.P. , Valido A.J.
Published: January 2014

This paper presents an integrated methodology for optimal design and control of nonlinear flexible mechanical systems, including minimum time problems. This formulation is implemented in an optimum design code and it is applied to the nonlinear behavior dynamic response. Damping and stiffness characteristics plus control driven forces are considered as decision variables. A conceptual separation between time variant and time invariant design parameters is presented, this way including the design space into the control space and considering the design variables as control variables not depending on time. By using time integrals through all the derivations, design and control problems are unified. In the optimization process we can use both types of variables simultaneously or by interdependent levels. For treating minimum time problems, a unit time interval is mapped onto the original time interval, then treating equally time variant and time invariant problems. The dynamic response and its sensitivity are discretized via space‐time finite elements, and may be integrated either by at‐once integration or step‐by‐step. Adjoint system approach is used to calculate the sensitivities.
Application of the Modified Compaction Material Model to the Analysis of Landmine Detonation in Soil with Various Degrees of Water Saturation
Authors: Grujicic M. , Pandurangan B. , Summers J.D. , Cheeseman B.A. , Roy W.N. , Skaggs R.R.
Published: January 2014

A series of transient non‐linear dynamics computational analyses of the explosion phenomena accompanying the detonation of a 100g C4 mine buried in sand to different depths is carried out using the software package AUTODYN. The mechanical response of sand under high deformation‐rate conditions has been represented using the modified compaction material model developed in our recent work [1]. While the mechanical response of the other attendant materials (air, gaseous‐detonation products and AISI 1006 mild steel) is accounted for using the material models available in literature. The results obtained (specifically, the temporal evolution of the sand overburden shape and pressure at various locations in air above the detonation site) were compared with their experimental counterparts for a (50wt%‐sand/50wt.%‐clay) soil obtained recently by Foedinger [2]. The comparison revealed that the modified compaction material model for sand can account reasonably well for the magnitude, spatial distribution and the temporal evolution of the dynamic loads accompanying detonation of shallow‐buried mines in soils with various clay and water contents.
Soil Properties from Low‐Velocity Probe Penetration
Authors: Johnson Jerome B. , Cargile James D. , Smith Donald M.
Published: January 2014

A physical model of low‐velocity probe penetration is developed to characterize soil by type, strength, maximum compaction, and initial density using Newton′s second law to describe the processes controlling probe momentum loss. The probe loses momentum by causing soil failure (strength), accelerating and compacting soil around the probe (inertia), and through frictional sliding at the probe/soil interface (friction). Probe geometry, mass, and impact velocity influences are incorporated into the model. Model predictions of probe deceleration history and depth of penetration agree well with experiments, without the need for free variables or complex numerical simulations.
On the Modeling of Beam Reinforced Thin Plates Using the Spectral Element Method
Authors: Campos N.B.F. , Arruda J.R.F.
Published: January 2014

Modeling beam reinforced thin plates at mid and high frequencies through the most commonly used methods such as finite and boundary element methods frequently leads to unsatisfactory results, since the accuracy of these methods depends on the relation between the dimensions of the elements in which the structure was discretized and the wavelength. Due to this characteristic, the modeling using these techniques will require that the size of the elements becomes smaller as the frequency increases, while its number needs to be increased. For structures that are usual in some areas, like the aerospace industry, this will be possible only with an unreasonable computational effort, which is responsible for restricting the use of these methods practically to low‐frequency applications. Semi‐analytical methods such as the spectral element method do not need mesh refinement at higher frequencies, but they were very limited in the geometries and boundary conditions that can be treated. This paper presents a spectral element for rectangular thin plates reinforced symmetrically along the sides with Euler beams, which can be used to model plates with arbitrary boundary conditions. The method was verified by comparing its results with those obtained from a Finite Element model.
Tactile Sensory Dysfunction in Children with ADHD
Authors: Ghanizadeh Ahmad
Published: January 2014

Objectives:While a group of children with ADHD may have normal behavioral responses to sensory stimuli, another group may be hyperreactive. The aim of this survey was studying association of tactile sensory responsivity with co-morbidity of oppositional defiant disorder (ODD) symptoms, subtypes of ADHD, and gender in children with ADHD.

Methods:The subjects were 81 children with ADHD from a child psychiatry clinic. The diagnoses were made according to DSM-IV diagnostic criteria. Tactile dysfunction Checklist was used to assess the three types of tactile sensory dysfunction including Hypersensitivity, hyposensitivity, and poor tactile perception and discrimination (PTPD).

Results:Their mean age was 8.4 (SD = 1.9) years. None of the gender, number of symptoms of ODD co-morbidity, and ADHD subtypes was as a predictor of scores of Hyposensitivity and PTPD subscales. Tactile defensiveness was not different between genders and different subtypes of ADHD.

Conclusions:Number of ODD symptoms in children with ADHD is a predictor in association with hypersensitivity score of tactile sensory function. Girls are no more than the boys impaired in Hypersensitivity aspect. Different subtypes of ADHD are not distinct disorders regarding to tactile sensory function.
Analysis of Control Policies and Dynamic Response of a Q‐Car 2‐DOF Semi Active System
Authors: Ihsan S.I. , Faris W.F. , Ahmadian M.
Published: January 2014

Several control policies of Q‐car 2‐DOF semiactive system, namely skyhook, groundhook and hybrid controls are presented. Their ride comfort, suspension displacement and road‐holding performances are analyzed and compared with passive system. The analysis covers both transient and steady state responses in time domain and transmissibility response in frequency domain. The results show that the hybrid control policy yields better comfort than a passive suspension, without reducing the road‐holding quality or increasing the suspension displacement for typical passenger cars. The hybrid control policy is also shown to be a better compromise between comfort, road‐holding and suspension displacement than the skyhook and groundhook control policies.
Writing Errors and Anosognosia in Amyotrophic Lateral Sclerosis with Dementia
Authors: Ichikawa Hiroo , Koyama Shinichi , Ohno Hideki , Ishihara Kenji , Nagumo Kiyomi , Kawamura Mitsuru
Published: January 2014

Amyotrophic lateral sclerosis (ALS) with dementia (ALS‐D) is known to exhibit characteristics of frontotemporal dementia. However, in clinical situations, it is often difficult to evaluate their cognitive functions because of impaired voluntary speech and physical disabilities. In order to identify characteristic and diagnostic cognitive symptoms of relatively advanced ALS‐D patients, we retrospectively reviewed the clinical features of seven cases of clinically definitive ALS who had dementia, impaired voluntary speech, and physical disability. Their medical records showed that six out of seven patients made writing errors, and all of the patients demonstrated anosognosia. The writing errors consisted of paragraphia such as substitution, omission, or syntactic errors with individual differences in error types. Dissociation between kana and kanji were also observed. Anosognosia was evaluated by a self‐rating scale with which the patients and the medical staff evaluated the patient′s physical ability; the results indicated a large discrepancy between the evaluation by the patients and the medical staff. We emphasize that aphasic writing errors have been underestimated, particularly in ALS‐D patients with impaired voluntary speech. We also reported that anosognosia was the most important and quantifiable symptom in ALS‐D. The relationship between writing errors and anosognosia should be investigated further.
Verbal Memory Impairments in Children after Cerebellar Tumor Resection
Authors: Kirschen Matthew P. , Davis-Ratner Mathew S. , Milner Marnee W. , Chen S. H. Annabel , Schraedley-Desmond Pam , Fisher Paul G. , Desmond John E.
Published: January 2014

This study was designed to investigate cerebellar lobular contributions to specific cognitive deficits observed after cerebellar tumor resection. Verbal working memory (VWM) tasks were administered to children following surgical resection of cerebellar pilocytic astrocytomas and age-matched controls. Anatomical MRI scans were used to quantify the extent of cerebellar lobular damage from each patient's resection. Patients exhibited significantly reduced digit span for auditory but not visual stimuli, relative to controls, and damage to left hemispheral lobule VIII was significantly correlated with this deficit. Patients also showed reduced effects of articulatory suppression and this was correlated with damage to the vermis and hemispheral lobule IV/V bilaterally. Phonological similarity and recency effects did not differ overall between patients and controls, but outlier patients with abnormal phonological similarity effects to either auditory or visual stimuli were found to have damage to hemispheral lobule VIII/VIIB on the left and right, respectively. We postulate that damage to left hemispheral lobule VIII may interfere with encoding of auditory stimuli into the phonological store. These data corroborate neuroimaging studies showing focal cerebellar activation during VWM paradigms, and thereby allow us to predict with greater accuracy which specific neurocognitive processes will be affected by a cerebellar tumor resection.
Dysgraphia in Patients with Primary Lateral Sclerosis: A Speech‐Based Rehearsal Deficit?
Authors: Zago S. , Poletti B. , Corbo M. , Adobbati L. , Silani V.
Published: January 2014

The present study aims to demonstrate that errors when writing are more common than expected in patients affected by primary lateral sclerosis (PLS) with severe dysarthria or complete mutism, independent of spasticity. Sixteen patients meeting Pringle’s et al. [34] criteria for PLS underwent standard neuropsychological tasks and evaluation of writing. We assessed writing abilities in spelling through dictation in which a set of words, non‐words and short phrases were presented orally and by composing words using a set of preformed letters. Finally, a written copying task was performed with the same words. Relative to controls, PLS patients made a greater number of spelling errors in all writing conditions, but not in copy task. The error types included: omissions, transpositions, insertions and letter substitutions. These were equally distributed on the writing task and the composition of words with a set of preformed letters. This pattern of performance is consistent with a spelling impairment. The results are consistent with the concept that written production is critically dependent on the subvocal articulatory mechanism of rehearsal, perhaps at the level of retaining the sequence of graphemes in a graphemic buffer. In PLS patients a disturbance in rehearsal opportunity may affect the correct sequencing/assembly of an orthographic representation in the written process.
Evaluation of the Autoparametric Pendulum Vibration Absorber for a Duffing System
Authors: Vazquez-Gonzalez Benjamın , Silva-Navarro Gerardo
Published: January 2014

In this work we study the frequency and dynamic response of a damped Duffing system attached to a parametrically excited pendulum vibration absorber. The multiple scales method is applied to get the autoparametric resonance conditions and the results are compared with a similar application of a pendulum absorber for a linear primary system. The approximate frequency analysis reveals that the nonlinear dynamics of the externally excited system are suppressed by the pendulum absorber and, under this condition, the primary Duffing system yields a time response almost equivalent to that obtained for a linear primary system, although the absorber frequency response is drastically modified and affected by the cubic stiffness, thus modifying the jumps defined by the fixed points. In the absorber frequency response can be appreciated a good absorption capability for certain ranges of nonlinear stiffness and the internal coupling is maintained by the existing damping between the pendulum and the primary system. Moreover, the stability of the coupled system is also affected by some extra fixed points introduced by the cubic stiffness, which is illustrated with several amplitude‐force responses. Some numerical simulations of the approximate frequency responses and dynamic behavior are performed to show the steady‐state and transient responses.
Anatomy of the Episodic Buffer: A Voxel‐Based Morphometry Study in Patients with Dementia
Authors: Berlingeri M. , Bottini G. , Basilico S. , Silani G. , Zanardi G. , Sberna M. , Colombo N. , Sterzi R. , Scialfa G. , Paulesu E.
Published: January 2014

In 2000 Baddeley proposed the existence of a new component of working memory, the episodic buffer, which should contribute to the on‐line maintenance of integrated memory traces. The author assumed that this component should be critical for immediate recall of a short story that exceeds the capacity of the phonological store. Accordingly, patients with Alzheimer’s dementia (AD) should suffer of a deficit of the episodic buffer when immediate recall of a short story is impossible. On the other hand, the episodic buffer should be somewhat preserved in such patients when some IR can occur (Baddeley and Wilson, 2002). We adopted this logic for a voxel‐based morphometry study. We compared the distribution of grey‐matter density of two such groups of AD patients with a group of age‐matched controls. We found that both AD groups had a significant atrophy of the left mid‐hippocampus; on the other hand, the anterior part of the hippocampus was significantly more atrophic in patients who were also impaired on the immediate prose recall task. Six out of ten patients with no immediate recall were spared at “central executive” tasks. Taken together our findings suggest that the left anterior hippocampus contributes to the episodic buffer of the revised working memory model. We also suggest that the episodic buffer is somewhat independent from the central executive component of working memory.
Combination of an Improved FRF‐Based Substructure Synthesis and Power Flow Method with Application to Vehicle Axle Noise Analysis
Authors: Liu C.Q.
Published: January 2014

In this paper, an improved FRF‐based substructure synthesis method combined with power flow analysis is presented and is used for performing a vehicle axle noise analysis. The major transfer paths of axle noise transmitted from chassis to vehicle body are identified and ranked based on power flows transmitted through bushings between the chassis and body. To calculate the power flows, it is necessary to know the reaction forces and the vibrations at the bushing locations on the body side. To this end, the body is represented in terms of experimentally derived frequency response functions (FRF′s) at the bushing locations, and the FRF′s are coupled with the FEA model of the chassis for performing a total system dynamic analysis. This paper also describes how the FRF′s of the vehicle body and the frequency dependent stiffness data of the bushings can be combined together with a simple formulation to better represent the dynamic characteristics of a full vehicle. A classical example is used to illustrates the concept of the method, and the method is then applied to a vehicle axle noise analysis with detailed procedure. The theoretical predictions are compared with experimentally measured results. Good correlation has been obtained.
Feature Comparison in Structural Health Monitoring of a Vehicle Crane
Authors: Kullaa J. , Heine T.
Published: January 2014

Vibration‐based structural health monitoring of a vehicle crane was studied. The performance of different features to detect damage was investigated after eliminating the normal operational variations using factor analysis. Using eight accelerometers, ten AR parameters from each record were identified for damage detection. Also transmissibilities between sensors were estimated. Damage was introduced with additional masses at different locations of the structure. All damage cases could be detected from either features using control charts, but transmissibilities proved to be more sensitive to damage than the AR coefficients.
Simultaneously Cooperative, but Serially Antagonistic: A Neuropsychological Study of Diagonistic Dyspraxia in a Case of Marchiafava‐Bignami Disease
Authors: Hirayama Kazumi , Tachibana Kaori , Abe Nobuhito , Manabe Hideaki , Fuse Takahisa , Tsukamoto Tetsuro
Published: January 2014

We describe a patient with Marchiafava‐Bignami disease who showed, in addition to signs of callosal interruption, a peculiar form of diagonistic dyspraxia. Unlike the typical diagonistic dyspraxia, both of the patient’s hands could simultaneously cooperate in a sequence of bimanual actions. More specifically, his right hand could start a commanded action with the cooperation of his left hand. However, once the action was completed, his left hand started an antagonistic action, undoing the result, with the cooperation of his right hand. Once this countermanding action was completed, the original action started again. These antagonistic actions repeated themselves alternately unless he was restrained. The patient′s diagonistic dyspraxia was apparent in only some bimanual actions, and he showed no diagonistic dyspraxia when performing voluntary actions; the antagonistic actions occurred in response to oral commands or by imitation. Magnetic resonance imaging showed symmetrical demyelination with partial necrosis in the genu, body, and anterior splenium of the corpus callosum. We speculate that the bimanual coordination is possible because part of the corpus callosum is intact, whereas the antagonistic actions may be caused by conflict between the two hemispheres due to interhemispheric disinhibition elicited by the demyelinated part of the corpus callosum.