Vertical Pitch Research Articles

Pitch-verticality and pitch-size cross-modal interactions

Two studies were conducted on cross-modal matching between pitch and sound source localization on the vertical axis, and pitch and size. In the first study 100 Hz, 200 Hz, 600 Hz, and 800 Hz tones were emitted by a loudspeaker positioned 60 cm above or below to the participant’s ear level. Using a speeded classification task, 30 participants had to indicate the sound source in 160 trials. Both reaction times and errors were analyzed. The results showed that in the congruent condition of high-pitched tones emitted from the upper loudspeaker, reaction times were significantly faster and the number of errors was significantly lower. Pitch was mapped on the vertical axis for sound localization. A main effect for sound source direction was also found. Tones coming from the upper loudspeaker were recognized faster and more accurately. Males were faster than females in identifying sound source direction. In the second experiment, 20 participants had to match 21 tones varying in pitch with 9 circles differing in visual angle on 42 trials. The results showed a clear inverse linear association between log-spaced tone pitch and circle diameter.

(Invited) Gate-All-Around Transistors Based on Vertically Stacked Si Nanowires

Gate-all-around (GAA) transistors based on vertically stacked horizontal nanowires are promising candidates to replace FinFETs in future CMOS technology nodes. First of all, GAA devices provide optimal electrostatic control over semiconducting nanowire channels, which enables downscaling of the gate length to below the FinFET limit, while maintaining low off-state leakage [1]. Besides, horizontally oriented nanowires are an evolutionary extension of FinFETs, as opposed to vertical nanowires which require more disruptive technology and design changes [2]. Finally, stacking of nanowires is relevant for enhancing the drive current per footprint. Based on these considerations, GAA transistors made of vertically stacked horizontal nanowires have been included in the ITRS roadmap to reduce the contacted gate pitch, which is a key figure of merit for CMOS device density, to below ~40 nm in 2019-2021 [3]. In the context of the industrial relevance described above, we present the fabrication of Si GAA devices on bulk Si substrates. Multiple processing aspects that are relevant for bulk CMOS technology definition are addressed, including stacking of 8-nm-diameter Si wires at 45-nm lateral pitch and 20-nm vertical pitch [4], and nanowire-compatible replacement metal gate processing in combination with threshold voltage tuning by dual work function metal integration [5]. Temperature restrictions for the formation of shallow trench isolation, and the interaction between N- and P-type junction formation on one hand and nanowire release processes on the other hand are discussed as well. [1] K. J. Kuhn, IEEE Trans. Electron Devices, vol. 59 (7), p.1813, (2012). [2] L. Liebmann et al., VLSI Tech. Dig., p.112 (2016). [3] The International Roadmap for Semiconductors (ITRS) 2.0, http://www.itrs2.net/ (2015). [4] H. Mertens et al., VLSI Tech. Dig., p.158 (2016). [5] H. Mertens et al., IEDM Tech. Dig., p.524 (2016). Figure 1

Multivoxel Pattern Analysis Reveals 3D Place Information in the Human Hippocampus.

The spatial world is three dimensional (3D) and humans and other animals move both horizontally and vertically within it. Extant neuroscientific studies have typically investigated spatial navigation on a horizontal 2D plane, leaving much unknown about how 3D spatial information is represented in the brain. Specifically, horizontal and vertical information may be encoded in the same or different neural structures with equal or unequal sensitivity. Here, we investigated these possibilities using fMRI while participants were passively moved within a 3D lattice structure as if riding a rollercoaster. Multivoxel pattern analysis was used to test for the existence of information relating to where and in which direction participants were heading in this virtual environment. Behaviorally, participants had similarly accurate memory for vertical and horizontal locations and the right anterior hippocampus (HC) expressed place information that was sensitive to changes along both horizontal and vertical axes. This is suggestive of isotropic 3D place encoding. In contrast, participants indicated their heading direction faster and more accurately when they were heading in a tilted-up or tilted-down direction. This direction information was expressed in the right retrosplenial cortex and posterior HC and was only sensitive to vertical pitch, which could reflect the importance of the vertical (gravity) axis as a reference frame. Overall, our findings extend previous knowledge of how we represent the spatial world and navigate within it by taking into account the important third dimension.SIGNIFICANCE STATEMENT The spatial world is 3D. We can move horizontally across surfaces, but also vertically, going up slopes or stairs. Little is known about how the brain supports representations of 3D space. A key question is whether horizontal and vertical information is equally well represented. Here, we measured fMRI response patterns while participants moved within a virtual 3D environment and found that the anterior hippocampus (HC) expressed location information that was sensitive to the vertical and horizontal axes. In contrast, information about heading direction, found in retrosplenial cortex and posterior HC, favored the vertical axis, perhaps due to gravity effects. These findings provide new insights into how we represent our spatial 3D world and navigate within it.

Comprehensive performance comparison of airfoil fin PCHEs with NACA 00XX series airfoil

Printed circuit heat exchanger (PCHE) can be used in supercritical carbon dioxide (S-CO2) Brayton cycle. The present study compares NACA 0020 airfoil fin PCHE with conventional zigzag PCHE by numerical analysis. Pressure drop of the former has a striking reduction while maintaining excellent heat transfer performance. Comparison on four NACA 00XX series airfoil fin PCHEs is performed to investigate the influence of airfoil profile on flow and heat transfer performance. With a fixed vertical pitch, heat transfer performance of NACA series airfoil fin PCHE increases as airfoil thickness increases. However, comprehensive performance, in which both flow and heat transfer are taken into account, degrades with increasing airfoil thickness. Among four NACA airfoil fin PCHEs presented in this paper, NACA 0010 airfoil fin PCHE demonstrates the best comprehensive performance.

Interaction of Asymmetric Films Around Boiling Cylinder Array: Homogeneous Interface to Chaotic Phenomenon

We report numerical study of film boiling around hot and horizontal cylinders in a saturated water pool to establish interfacial interactions leading toward dryout. Volume of fluid-based finite-volume discretization is performed in the domain for incorporation of source term in mass momentum and energy conservation equations due to phase change. At first, film boiling around single cylinder is simulated at different surface temperatures to understand unconstrained film growth and subsequent film bubble release due to buoyancy. Using velocity vectors and temperature contours, effect of film flow dynamics on bubble departure is depicted. This study has been extended further with multiple cylinders in three different stacking arrangements in order to understand the interaction of films in vicinity. Vertical interaction between cylinders leads to suppression of bubble release at the lower cylinder in comparison to the upper one. In the case of horizontal interactions, bubbles attract each other and merge, provided favorable pitch between cylinders and temperatures of the surfaces is maintained. Offset four cylinders stack maintaining vertical and horizontal pitch allows both lateral vapor affinity and bubble suppression in the lower most cylinder simultaneously. With time interaction of accumulated vapor films around cylinders hinders replenishment of fresh liquid to the hot surfaces leading toward chaotic phenomena or dryout in boiling heat transfer.

The method and error analysis of deep-sea pose measurement system

The deep-sea pose measurement system can measure the relative distance and angle of two subsea pipelines which the connection of submarine pipelines project need, and the success of connection is mostly decided by high measurement accuracy. According to deep-sea environment, paper designs a measuring method by deep-sea pipeline pose measurement system which bases on the stretching wire. In order to increasing measurement accuracy, paper analyses the transitive relation of error source which impact system measurement accuracy, and gets the impact laws of error sources which include the orthogonal angle, extension arm vertical pitching angle and horizontal swing angle, etc. We revise the measuring result by binary linear regression analysis to improve the measurement accuracy. Through constructing the test platform, we compare measuring value and true value of the pipelines pose parameters. The experimental results show that the distance error is ±30 mm inside, and that the angle error is ±0.7° inside within 7 m after correction. We reduce the measurement error of the pose measurement system, and verify the correctness of the theoretical.

Analysis of Train Suspension System Using MR dampers

This paper deals with introducing MR dampers to the Train Suspension System for improving the ride comfort of the passengers. This type of suspension system comes under Semi-active suspension system which utilizes the properties of MR fluid to damp the vibrations. In case of high speed trains, the coach body is subjected to vibrations due to vertical displacement, yaw and pitch movements. When the body receives these disturbances from the ground,the transmission of vibrations to the passenger increases which affect the ride comfort. In this work, the equations of motion of suspension system are developed for both conventional passive system and semi-active system and are modelled in Matlab/Simulink and analysis has been carried out. The passive suspension system analysis shows that it is taking more time to damp the vibrations and at the same time the transmissibility of vibrations is more.Introducing MR dampers,vertical and angular displacements of the body are computed and compared. The results show that the introduction of MR dampers into the train suspension system improves ride comfort.

Hydrodynamic and Thermal Performance of Microchannels With Different In-Line Arrangements of Cylindrical Micropin Fins

This study presents results on the hydrodynamic and thermal characteristics of single-phase water flows inside microchannels (MCs) with different micropin fin (MPF) configurations. Different inline arrangements of micropin fins were considered over Reynolds numbers ranging from 20 to 160. The computational studies were performed using the commercial software ansys 14.5. The hydrodynamic performances of the configurations were compared using two parameters, namely, pressure drop and friction factor while the comparison in their thermal and thermal-hydraulic performances were based on Nusselt number and thermal performance index (TPI). Wake-pin fin interactions were carefully analyzed through streamline patterns in different arrangements and under different flow conditions. The results showed strong dependencies of all four evaluated performance parameters on the vertical pitch ratio (ST/D). Weaker dependencies on height over diameter ratio (H/D), horizontal pitch ratio (SL/D), and minimum available area (Amin) were observed. With an increase in the Reynolds number, extension of the wake regions behind MPFs was observed to be the paramount factor in increasing pressure drop and Nusselt number. Regarding TPI, two adverse trends were observed corresponding to different ST/D ratios, while the effect of SL/D ratio was unique. For friction factors, H/D and SL/D ratios of 1 and 1.5, respectively, led to minimum values, while different ST/D ratios are needed for each diameter size for the maximum performance. Moreover, a twofold increase in Reynolds number resulted in about 40% decrease in friction factor in each configuration.

Effective Control Method of the Active Damper System Against the Multidirectional Vibration in the Superconducting Magnetically Levitated Bogie

Numerical analysis of the superconducting magnetically levitated bogie (JR Maglev) has been studied. In this system, electrodynamic suspension with the null-flux configuration is applied to keep the levitation and guidance position of the train without gap control. However, the damping factor of the system is little. The active damper coil is introduced to increase the damping factor. It has a large effect on reducing the vertical vibration. However, when the vertical vibration and pitching motion occur simultaneously, it does not control the vibration perfectly. The control method of the active damper coil is studied. The improved switching function (combined switching) that has an effect on the multidirectional vibration is modeled. Running simulation when the bogie passes the guideway displacement has been undertaken. The active damper that is controlled by the combined switching decreases the multidirectional vibration.

Modeling of Wing Flapping Motion

In flying animal world, there are different flapping motions to produce lift and thrust depending on their species and size. Recent development in Unmanned Aerial Vehicle had tried to mimic flying animal. Rather than having two separate systems in providing lift and thrust, the wing upstroke and downstroke movement combined with wing twisting produce the necessary lift and thrust. Insects and some small birds have even the ability to fly hover.The present study is focused on the modeling of wing flapping motion. Instead of only accommodating flapping motion in a vertical plane and spanwise pitching motion, the model permits to include wing lead-lag motion in the horizontal plane. This more degree of freedom permit to model more complex wing flapping motion.

A comprehensive experimental investigation on the influences of the process variables on warm incremental forming of Ti-6Al-4V titanium alloy using a simple technique

The incremental forming has recently acquired a significant importance in various applications, such as automotive, aerospace, and medical industries. The present investigation is concerned with the warm incremental forming of Ti-6Al-4V titanium alloy. With this regard, the groove test was employed as a simple technique to study the effects of different variables, namely, the process temperature, the vertical pitch, and the tool diameter, on the forming limit diagram of the material, the springback, drawing depth, final temperature of the sheet, and the thickness variation of the product. The sheet temperature was the most important parameter affected by the interfacial friction and the other process variables. The experimental findings illustrated that the greater the vertical pitch and/or the tool diameter, the larger the formability and drawing depth of the sheet sample before its fracture. Moreover, decreasing the tool diameter and increasing the vertical pitch and the initial process temperature resulted in more thickness reduction. The actual process temperature simultaneously affected the elastic modulus and the flow stress of the component. However, the flow stress reduction due to the temperature rise overcame the elastic modulus decrease and, finally, the springback was lower at higher process temperatures.

단순 차량 모델을 이용한 능동 현가장치 제어기 설계

This paper presents a method to design a controller for active suspension with 1-DOF decoupled models. Three 1-DOF decoupled models describing vertical, roll and pitch motions are used to design a controller in order to generate a vertical force, roll and pitch moments, respectively. These control inputs are converted into active suspension forces with geometric relationship. To design a controller, a sliding mode control is adopted. Frequency domain analysis and simulation on vehicle simulation software, CarSim<TEX>$^{(R)}$</TEX>, show that the proposed method is effective for ride comfort.

Vibration Analysis of 5-DOF Vehicle Model under Stochastic Road Surface Excitation

Considering human body vertical motion, vehicle body vertical motion, pitch movement and vertical jump of front and rear wheels, a five-degree-of-freedom vehicle model is established to study basic driving characteristics of the vehicle. Using Fourier transform method, acceleration power spectral density of the seat and the mean square value curves of seat vertical weighted acceleration are obtained by numerical simulation. Combined with comfort provision standards, the influence of vehicle model parameters and speed on seat acceleration power spectral density and vertical root-mean-square value of seat weighted acceleration are analyzed. Results show that the stiffness and damping of the seat have no significant effect on seat acceleration power spectral density, and seat acceleration PSD increases with increasing front or rear suspension stiffness, but it decreases with increasing front or rear suspension damping. It should also be concluded that the model stiffness and the mean square value of seat vertical weighted acceleration present positive correlation in general, but seat vertical weighted acceleration decrease first and then increase when model damping increase. Such analysis results can provide reference for the parameter optimization design of the automobile.

Accuracy evaluation of the optical surface monitoring system on EDGE linear accelerator in a phantom study

Frameless stereotactic radiosurgery (SRS) requires dedicated systems to monitor the patient position during the treatment to avoid target underdosage due to involuntary shift. The optical surface monitoring system (OSMS) is here evaluated in a phantom-based study. The new EDGE linear accelerator from Varian (Varian, Palo Alto, CA) integrates, for cranial lesions, the common cone beam computed tomography (CBCT) and kV-MV portal images to the optical surface monitoring system (OSMS), a device able to detect real-time patient׳s face movements in all 6 couch axes (vertical, longitudinal, lateral, rotation along the vertical axis, pitch, and roll). We have evaluated the OSMS imaging capability in checking the phantoms׳ position and monitoring its motion. With this aim, a home-made cranial phantom was developed to evaluate the OSMS accuracy in 4 different experiments: (1) comparison with CBCT in isocenter location, (2) capability to recognize predefined shifts up to 2° or 3cm, (3) evaluation at different couch angles, (4) ability to properly reconstruct the surface when the linac gantry visually block one of the cameras. The OSMS system showed, with a phantom, to be accurate for positioning in respect to the CBCT imaging system with differences of 0.6 ± 0.3mm for linear vector displacement, with a maximum rotational inaccuracy of 0.3°. OSMS presented an accuracy of 0.3mm for displacement up to 1cm and 1°, and 0.5mm for larger displacements. Different couch angles (45° and 90°) induced a mean vector uncertainty < 0.4mm. Coverage of 1 camera produced an uncertainty < 0.5mm. Translations and rotations of a phantom can be accurately detect with the optical surface detector system.

Real-time rail–wheel wear damage control

ABSTRACTThis paper presents the performance of a real-time rail–wheel wear damage control system with respect to different operation conditions. In particular, an investigation into the wear growth rate control under changing wheel–rail friction conditions and different operation speeds is performed. Simulation using a mathematical model considering longitudinal–vertical–pitch dynamics of a locomotive running on straight tracks shows that the proposed controller can effectively reduce the rail–wheel wear damage by limiting mass loss rate, particularly during acceleration under low and medium speeds.

The effect of acute unilateral inflammation of the equine temporomandibular joint on the kinematics of mastication

Diseases of the temporomandibular joint (TMJ) are well reported in man and some domestic animals other than the horse. The pathophysiology of equine TMJ disease and the effects of disease on the kinematics of mastication are unknown. To determine whether transient unilateral inflammation of the equine TMJ results in alterations in the masticatory cycle. An experimental controlled study utilising 6 horses of various ages with normal dentition. Each horse was equipped with an optical motion tracking (kinematic) system. Horses were observed chewing grass hay over 3min intervals. Regardless of the initial side of the power stroke in the masticatory cycle, lipopolysaccharide (LPS) was injected in the left TMJ in each horse and the horses were reassessed after 6h. Four horses developed effusion of the injected TMJs; 2 of these also began quidding. All horses injected on the original side of the power stroke switched sides while the 2 injected on the contralateral side did not. All horses developed reduced vertical pitch (vertical opening) of the mandible. Overall, rostrocaudal movement of the mandible did not change; however, the timing of this movement relative to the phase of the masticatory cycle did. Injection with LPS did not affect the amount of lateral movement of the mandible. Injection of LPS into the TMJ significantly altered the masticatory cycle compared with baseline values representing avoidance behaviour due to inflammation of the joint, despite which the horses continued to eat using the contralateral mandible. Lipopolysaccharide administration also led to quidding and a loss of feed efficiency (in some individuals).

Full-car active suspension based on H&lt;SUB align="right"&gt;2/generalised H&lt;SUB align="right"&gt;2 output feedback control

This paper establishes a 15 degree-of-freedom (DOF) full-car simulation model for the car Hongqi HQ3. The effectiveness of the model is evaluated by comparison of the real data of HQ3 with the data of the model. Output feedback control of the active suspension is designed based on a half-car model. High quality ride comfort is achieved by minimising the H2 norm from disturbances on the road to the vertical acceleration and the pitch acceleration of the car, while safety constraints such as suspension dynamic travels, static/dynamic load ratios and normalised load flows are guaranteed by the generalised H2 norm. The 15 DOF full-car model, together with the left and the right output feedback controllers, form a closed-loop system. The simulation result of the full-car shows that the active suspension can greatly reduce the vertical acceleration, pitch acceleration and roll acceleration as well as satisfy all constraints.

Ride Comfort Performance Improvement of Electric Vehicle (EV) Conversion Using SAS-Controlled Active Suspension System

This paper presents vehicle’s ride comfort performance evaluation after the conversion into an electric vehicle (EV) and the possible ride comfort improvement by an active suspension system have been investigated. The evaluations were done using a validated 7 degrees of freedom of vehicle’s ride model. The mathematical modelling of the vehicle’s ride as well as its validations was developed in order to predict the vehicle’s ride behaviours. The model was then integrated with the active suspension system in order to improve the EV conversion’s ride comfort performance. It was found that the modifications towards an EV conversion do not affect vehicle’s ride comfort performance significantly, except it changes only the vehicle’s vertical displacement, pitch rate and pitch angle responses. However, further application of an active suspension system in EV conversion was found to be able to improve all of the observed responses for ride comfort performance of an EV conversion by overall improvement of 71.1 percent.

Active Suspension System to Improve Ride Comfort Performance of Electric Vehicle (EV) Conversion

This paper presents an evaluation of ride comfort performance of a passenger vehicle when converted into an electric vehicle (EV). The evaluations were done using a validated 7 degrees of freedom of vehicle’s ride model. The developed vehicle’s ride model was used to predict the vehicle’s ride behaviours when subjected to random road profiles. The ride model of EV conversion was then integrated with the active suspension system in order to further improve the EV conversion’s ride comfort performance. It was found that the modifications of a normal passenger vehicle into an EV conversion do not affect vehicle’s ride comfort performance significantly, except the conversion changes only the magnitude of vehicle’s vertical displacement, pitch rate and pitch angle responses. However, the integration of an active suspension system in EV conversions ride model was improves the observed responses of EV conversion’s ride comfort performance by overall improvement of 65.7 percents.

Study of Wheel-Rail Vibration in Railways

Together with the rapid development of high-speed railways, extensive research into railway technologies is compulsory, especially on the aspect of dynamic interactions between vehicle and railway line, in order to guarantee the operational security of vehicles at high speed and improve the passengers comfort. The increase in the severity of the dynamic interaction between wheel and rail arises from the increasing speed of trains. As a result, it is necessary to analyze for the characteristics of wheel-rail vibration. The curve is an important component of a railway line and is usually the very source of wheel-rail vibration, especially at the time when a vehicle rapidly passes through a railway line, and will seriously affect the safety and comfort of the vehicle. At present, the usual practice is to only take some limit values to design the vertical section of railway lines, such as the maximum slope and the minimum slope length, according to the grade of a certain right line. Moreover, the existing studies on the vertical curve focused more on the vertical section parameters without considering the influence of these parameters on the dynamic interaction between the vehicle and line. The aforementioned studies involve either static or quasi-static analysis. There is little literature available on using a systematic method based on dynamics to study wheel-rail vibration, and some related issues are mainly the assessment making for a certain line. Based on the multi-body dynamics and the existing achievements, this paper aims to systematically investigate the influence of vertical section parameters on the characteristics of wheel-rail vibration and discuss the relationship between the acting region of wheel-rail vibration and these parameters. Furthermore, the characteristics of wheel-rail vibration at different velocities are investigated. The evaluation of the vibrations behavior in a railway vehicle is one of the matters taken into consideration even from the design stage. The decrease of vibrations to an acceptable level in terms of running behavior, safety, passengers comfort and track fatigue is required by regulations at European level for vehicle homologation and their admission into traffic.The vibrations of railway vehicles are mainly produced by the interaction between the track and the rail. Regarding a track with irregularities or deviations from the ideal geometry it creates vibrations of vehicles, which are developed both vertically and horizontally. These two types of vibrations are decoupled, though, due to the construction symmetries (inertial, elastic, plastic, linear and geometric). As for the vertical vibrations, the bounce and pitch vibrations are the main reasons of the vehicles dynamic behavior. They can be studied on simple models, one or two degrees of freedom, based on the hypothesis of excitation symmetry, by considering only one mobile base as if the wheel-sets had identical motions . This is the reason why the results with these models can be overestimated.This paper presents the influence of vehicle wheel bases and of the steel tire in running conditions, depending on some geometric characteristics. The influence will be further reflected by the vehicles response to the crossing over the rolling track random irregularities and in the magnitude of the vertical accelerations. This is the reason why the complete model of a passenger vehicle has been accounted for, including the car body bending vibrations. The movement equations have been treated in an original manner and brought to a form that points out the symmetrical and anti-symmetrical decoupled movements of vehicle and their excitation modes.