Low Pitch Research Articles

Elimination of splash damage for smaller scribe widths in next-gen memory devices via stealth dicing

Scattered light damage (splash) is one of the common defects that can be observed from the stealth dicing process, and it is mainly due to the interaction of the pulsed laser beam with the micro-crack and modified layer formed. This might cause thermal damage on the active layer of the die and degrade the reliability and yield of the device. The development of new technology node for memory devices aims to reduce scribe width, thereby increasing the number of dies per wafer. The ongoing trend towards scribe width reduction from 120 μm to current sub-60 μm, results in increased throughput and decreased cost per die. Furthermore, this reduction allows for greater functionality integration within a confined space, thereby enhancing overall device performance. Hence, the elimination of splash during the SD process is imperative to enable further shrinking of scribe width. This paper focuses on the impact of pulse pitch and distance from 1st focal depth to silicon (Si) frontside on the maximum splash distance. Lower pulse pitch and lower distance from 1st focal depth to Si frontside will introduce higher splash distance. An empirical model for splash elimination was established to determine the critical distance from 1st focal depth to Si frontside as a function of pulse pitch.

Vertical prism adaptation, but not sound presentation, modulates the visuospatial representation: A manual line-bisection study

The present study aimed at testing whether vertical prism adaptation (PA) can modulate vertical visuospatial representation, assessed with a vertical manual line-bisection (MLB) task (Experiment 1). In a second time, we wanted to investigate the potential influence of sound presentation during such a task. Sound is a spatially valued element that has previously been reported to modify horizontal visuospatial representation. In Experiment 2, we presented either a high pitch, a low pitch, or no sound during the same MLB as in Experiment 1. With this experiment, we also searched for an eventual interaction between the effect of sound presentation and the potential cognitive aftereffects of vertical PA on visual representation.Both Experiments 1 and 2 were constructed with the same design and conducted with two distinct groups of young healthy right-handed participants. First, we assessed the initial sensorimotor state with an open-loop pointing task, and the initial representational state through a vertical MLB (with addition of sound for Experiment 2). Then participants were submitted to a 16-minute PA procedure and were tested again on the open-loop pointing task and the MLB to assess the aftereffects following prism removal.Our results showed sensorimotor aftereffects following both upward and downward PA, in a direction opposed to the optical deviation used. The early aftereffects measured following PA were symmetrical, but at the end of the experiment the residual aftereffects were smaller following downward PA than upward PA. We also provide a new insight on the aftereffects of vertical PA on visuospatial representation, showing that downward PA (but not upward PA) can produce an upward bias on the manual line-bisection task. This is the first proof of such cognitive aftereffects following vertical PA. However, we found no effect of sound presentation on the vertical visual space representation and no interaction between PA and sound presentation.

Influence of the contraction section configuration and deflector layout density on the wind-snow flow characteristics inside the ice snow wind tunnel for railway vehicles

The significant accumulation of snow and ice in the bogie region severely compromises operational quality and poses a safety hazard to high-speed trains. To enhance testing capabilities for assessing ice and snow accumulation within bogie regions, this study conducts numerical investigations into the influence of contraction section configuration and deflector layout density on wind-snow flow quality within an ice and snow wind tunnel. The predictive accuracy of the numerical method is comprehensively validated against wind-snow wind tunnel tests, involving a comparison of airflow velocity in the test section and snow accumulation thickness on the channel's floor. The results demonstrate that the coupled numerical method of Improved Delayed Detached Eddy Simulation (IDDES) and Discrete Phase Model (DPM) is a reliable tool for analyzing wind-snow flow characteristics within an ice and snow wind tunnel. Furthermore, compared to the vickers curve and bicubic curve, quintic curves applied to the contraction section consistently compress and accelerate airflow. This contributes to a more uniform flow characterized by lower stream-wise fluctuation levels, pitch angles, and yaw angles in the test section, thereby significantly enhancing the overall flow quality of wind and snow. Thus, the quintic curves or smoother curves are recommended for the design of the contraction section in ice and snow wind tunnels. Moreover, increasing the deflector number leads to a noticeable improvement in flow quality inside the test section, while resulting in increased snow accretion on the windward surfaces of deflectors. Hence, a medium-level deflector density is suggested for designing ice and snow wind tunnels to achieve a better balance between flow quality and the additional snow accretion inside the channel.

Improving local path planning for UAV flight in challenging environments by refining cost function weights

AbstractUnmanned Aerial Vehicles (UAV) constantly gain in versatility. However, more reliable path planning algorithms are required until full autonomous UAV operation is possible. This work investigates the algorithm 3DVFH* and analyses its dependency on its cost function weights in 2400 environments. The analysis shows that the 3DVFH* can find a suitable path in every environment. However, a particular type of environment requires a specific choice of cost function weights. For minimal failure, probability interdependencies between the weights of the cost function have to be considered. This dependency reduces the number of control parameters and simplifies the usage of the 3DVFH*. Weights for costs associated with vertical evasion (pitch cost) and vicinity to obstacles (obstacle cost) have the highest influence on the failure probability of the local path planner. Environments with mainly very tall buildings (like large American city centres) require a preference for horizontal avoidance manoeuvres (achieved with high pitch cost weights). In contrast, environments with medium-to-low buildings (like European city centres) benefit from vertical avoidance manoeuvres (achieved with low pitch cost weights). The cost of the vicinity to obstacles also plays an essential role and must be chosen adequately for the environment. Choosing these two weights ideal is sufficient to reduce the failure probability below 10%.

Prosodic features of polite speech

Abstract This paper uses interactional data to investigate the acoustic characteristics of polite or deferential speech in Korean. We asked fourteen Korean speakers to perform two tasks with two different interlocutors: a status superior and a friend. Consistent with previous studies of non-interactional data, deferential speech has lower pitch and shimmer, and quieter final syllables. However, divergent from previous studies, deferential speech featured higher jitter (in some locations), higher shimmer and higher H1-H2 (on one task). Through analysis of different locations in prosodic structure, we found that females used more pitch variation on final syllables in deferential speech. We argue that these mixed results show the importance of context in signalling vocal politeness, and also complexities of using interactional data. The findings advance the study of multimodal politeness beyond the analysis of experimental data.

Heat transfer enhancement of different ribbing pitched semi-closed microstructure tube bundles fabricated by deformational cutting method

The study investigates the limitations posed by low-value heat transfer coefficients and higher wall superheat in conventional tube bundles, which adversely impact the performance of heat exchangers. To address this challenge, semi-closed microstructure tubes, created via deformational cutting at ribbing pitches of 300 µm and 400 µm, are proposed as a potential solution. The research centers on analyzing the two-phase boiling heat transfer performance of these microstructure tubes arranged in 2 × 3 staggered tube bundles. A comparative analysis is conducted, evaluating the thermal effectiveness of the microstructure tube bundles against a 2 × 3 smooth tube bundle and a copper-coated tube bundle under varying mass flux, heat flux, and pitch-to-diameter ratios. The experimental findings indicate the superior heat transfer performance of both microstructure tube bundles, with reduced wall superheat compared to other tube bundles. The findings further indicate that the 2 × 3 semi-closed microstructure tube bundle with a higher ribbing pitch outperforms the microstructure with a lower ribbing pitch. The 2 × 3 high-pitched microstructure tube bundle exhibits a maximum enhancement of 420 % over the 5 × 3 smooth tube bundle and 340 % over the 2 × 3 smooth tube bundle. Moreover, it surpasses the performance of copper-coated tube bundles by 230 % and outperforms its lower-pitch counterpart by 70 %. Particularly, the use of microstructure tube bundles allows for a reduction in the number of tubes required in the heat exchanger configuration without compromising its performance, promoting compactness and cost-effectiveness. Overall, the study highlights the feasibility of implementing these tubes in the two-phase heat exchanger owing to their superior performance compared to conventional tubes.

Clinical evaluation of pulsatile tinnitus: history and physical examination techniques to predict vascular etiology

BackgroundPulsatile tinnitus (PT) may be due to a spectrum of cerebrovascular etiologies, ranging from benign venous turbulence to life threatening dural arteriovenous fistulas. A focused clinical history and physical examination...

Analyzing Vocal Fold Frequency Dynamics Using High-Speed 3D Laser Video Endoscopy.

To examine changes in lateral and vertical vibratory motion along the anterior, middle, and posterior sections of the vocal folds, as a function of vocal frequency variations. Absolute measurements of vocal fold surface dynamics from high-speed videoendoscopy with custom laser endoscope were made on 23 vocally healthy adults during sustained /i:/ production at 10%, 20%, and 80% of pitch range. The 3D parameters of amplitude (mm), maximum velocity opening/closing (mm/s), and mean velocity opening/closing (mm/s) were computed for the lateral and vertical vibratory motion along the anterior, middle, and posterior sections of the vocal folds. Linear mixed model analysis was conducted to evaluate the differences in (a) vocal frequency levels (high vs. normal vs. low pitch), (b) axis level (vertical vs. lateral), (c) position level (anterior vs. middle vs. posterior), and (d) gender differences (male vs. female). Overall, the superior surface vertical motion of the vocal fold is greater compared with the lateral motion, especially in males. Along the superior surface, the mean and maximum closing velocities are greater posteriorly for low pitch. The location (anterior, middle, and posterior) along the superior surface is relevant only for vocal fold closing rather than opening, as the dynamics are different along the various locations. The study highlights the significance of assessing the vertical motion of the superior surface of the vocal fold to understand the complex dynamics of voice production. NA Laryngoscope, 134:3267-3276, 2024.

Friction stir extrusion of thin AA 7075-T6 into low-carbon steel: Effects of low weld pitch value

Friction stir extrusion, a derivative process of friction stir welding, forms a mechanical joint between workpieces by forging one into a prefabricated geometry within the other. Thin sheet AA7075-T651 extrusion joints were made into an O-ring dovetail channel within a low-carbon steel workpiece. The effects of low weld pitch process parameters on joint characteristics between the extruded thin sheet AA7075-T651 and low-carbon steel were observed. The weld pitch was varied from 0.02 to 0.05 mm rev−1. No material mixing was observed. Tensile-shear test results were normalised by sample width. The 0.04 mm rev−1 weld pitch group yielded the highest average joint strength at 493 N mm−1. The weld pitch parameters reduced machine in-process forces without a large decrease in joint strength.

Clinical applications for automatic detection of creaky voice

Creaky voice is a voice quality in which a low amount of subglottal air pressure, a condensed vocal fold structure, and a high closed quotient of vibration combine to create the auditory percept of a series of pulses at a low pitch. While this voice quality is often nonpathological, it can also co-occur with vocal pathologies. Identification of creak in the speech signal is most often done manually. Automatic creak detection algorithms have been created to streamline and produce replicable workflows. These algorithms have steadily increased in reliability, with COVAREP (Degottex et al., 2014) as the newest state-of-the-art. While preliminary studies have demonstrated promising findings using artificial neural networks with clinical data, artificial neural networks typically improve with diverse data testing. The current study implements COVAREP on a novel dataset, both in terms of speakers and speech types. Deidentified patient diagnoses were matched to audio recordings collected from January 2021 through September 2023. Relevant portions of audio recordings were extracted using a Praat script, and COVAREP was implemented on the extracted audio files in MATLAB. Ongoing analyses correlating percentage of creak detected and vocal pathology diagnoses will be discussed. Finally, the results will be compared to those of previous work.

Multiple timescales of context shape the perceptual sensitivity to natural pairings of musical pitch and timbre

Musical pitch and timbre (specifically, spectral shape) covary perceptually: lower pitches are associated with darker timbres (less higher-frequency energy) and higher pitches are associated with brighter timbres (more higher-frequency energy). We examined this relationship at multiple timescales of context: trial-level (rates of performance improvement within a testing block), block-level (differences in performance across blocks), session- level (performance as a function of testing block order), and longer-term experience (musical training / background). Musical pitches were labeled as low (C4) or high (G4) from various instruments (trumpet, oboe, trombone, tuba). Testing blocks paired pitch and timbre together to either respect (Consistent) or violate (Reversed) their covariance. All timescales of context contributed to performance, producing clear patterns across experiments. Pitch labeling was poorer in Reversed blocks, but showed steeper rates of improvement than did Consistent blocks (which were often near/at ceiling levels). These patterns were moderated by which condition was tested first in the experiment and by the introduction of trial-by-trial feedback. Greater musical training was consistently correlated with higher accuracy, but adding feedback extinguished this pattern for Consistent blocks. Thus, context on a host of timescales shapes perceptual sensitivity to the natural covariance between musical pitch and timbre.

Auditory aversive generalization learning prompts threat-specific changes in alpha-band activity.

Pairing a neutral stimulus with aversive outcomes prompts neurophysiological and autonomic changes in response to the conditioned stimulus (CS+), compared to cues that signal safety (CS-). One of these changes-selective amplitude reduction of parietal alpha-band oscillations-has been reliably linked to processing of visual CS+. It is, however, unclear to what extent auditory conditioned cues prompt similar changes, how these changes evolve as learning progresses, and how alpha reduction in the auditory domain generalizes to similar stimuli. To address these questions, 55 participants listened to three sine wave tones, with either the highest or lowest pitch (CS+) being associated with a noxious white noise burst. A threat-specific (CS+) reduction in occipital-parietal alpha-band power was observed similar to changes expected for visual stimuli. No evidence for aversive generalization to the tone most similar to the CS+ was observed in terms of alpha-band power changes, aversiveness ratings, or pupil dilation. By-trial analyses found that selective alpha-band changes continued to increase as aversive conditioning continued, beyond when participants reported awareness of the contingencies. The results support a theoretical model in which selective alpha power represents a cross-modal index of continuous aversive learning, accompanied by sustained sensory discrimination of conditioned threat from safety cues.

Experimental investigation of wave induced flapping foil for marine propulsion: Heave and pitch stiffness effect

The submerged hydrofoil has the capability to harness wave energy and convert it into thrust to work with the ship's power system. The current series of experiments investigated the interaction of a passive submerged hydrofoil with regular waves through a comparison of the generated horizontal forces. Springs provide the restoring force for the hydrofoil's heave/pitch motion, corresponding to heave spring and pitch spring. Maintaining a constant heave spring stiffness (490 N/m), subsequent statistical analysis summarized the force trends at different pitch stiffnesses (16–300 N/m) and suggested an optimal pitch spring stiffness in regular waves. A pulse-shaped force signal was observed and explained as a result of low pitch stiffness. Experiments with different spring setups revealed that the heave spring contributes to the harmonic force generated by the fully passive foil. Additionally, by varying wave conditions with limited wave amplitudes and frequencies, tests reproduced the variation of force signals over time and assessed their dependence on wave parameters.

Effects of speech rate modifications on phonatory acoustic outcomes in Parkinson's disease.

Speech rate reduction is a global speech therapy approach for speech deficits in Parkinson's disease (PD) that has the potential to result in changes across multiple speech subsystems. While the overall goal of rate reduction is usually improvements in speech intelligibility, not all people with PD benefit from this approach. Speech rate is often targeted as a means of improving articulatory precision, though less is known about rate-induced changes in other speech subsystems that could help or hinder communication. The purpose of this study was to quantify phonatory changes associated with speech rate modification across a broad range of speech rates from very slow to very fast in talkers with and without PD. Four speaker groups participated: younger and older healthy controls, and people with PD with and without deep brain stimulation of the subthalamic nucleus (STN-DBS). Talkers read aloud standardized sentences at 7 speech rates elicited using magnitude production: habitual, three slower rates, and three faster rates. Acoustic measures of speech intensity, cepstral peak prominence, and fundamental frequency were measured as a function of speech rate and group. Overall, slower rates of speech were associated with differential effects on phonation across the four groups. While all talkers spoke at a lower pitch in slow speech, younger talkers showed increases in speech intensity and cepstral peak prominence, while talkers with PD and STN-DBS showed the reverse pattern. Talkers with PD without STN-DBS and older healthy controls behaved in between these two extremes. At faster rates, all groups uniformly demonstrated increases in cepstral peak prominence. While speech rate reductions are intended to promote positive changes in articulation to compensate for speech deficits in dysarthria, the present results highlight that undesirable changes may be invoked across other subsystems, such as at the laryngeal level. In particular, talkers with STN-DBS, who often demonstrate speech deterioration following DBS surgery, demonstrated more phonatory detriments at slowed speech rates. Findings have implications for speech rate candidacy considerations and speech motor control processes in PD.

3D-integrated pixel circuit for a low power and small pitch SOI sensor

Targeting on low power consumption and high spatial resolution, the CPV-4 SOI pixel sensor has been developed. Its pixel circuit requires about 120 transistors to implement the analog-digital mixed signal processing functionality within a compact pixel area of 17 μm × 21 μm. By utilizing 3D vertical integration, sensing diode and analog front-end are realized in the lower-tier chip, while hit information storage and sparse readout are achieved in the upper-tier chip, thereby minimizing its pixel size and power consumption. This work presents the pixel circuit design and the test results on the completed 3D chips. The feature of SOI pixel process and the 3D integration are also highlighted in this article.

The power-extraction regime of a figure-eight trajectory flapping-foil turbine

At specified Reynolds numbers Re=ρvc/μ=5×105, this study investigates the power-extraction regime of a flapping-foil turbine executing a figure-eight trajectory. This study thoroughly explored the impacts of trajectory shape, heave and pitch amplitudes, phase difference, and pitch axis location on the power-extraction regime of a flapping turbine. A figure-eight trajectory substantially bolsters the energy harvesting capacity, achieving a peak efficiency of up to 50%. This trajectory capitalizes on the energy generated from the drag encountered by the flapping foil, thereby marking a significant efficiency breakthrough. This could denote a considerable progression for flapping foils tailored for heave and pitch motions since the free stream can be optimally harnessed by the trajectory we have established. In scenarios where the flapping foil undergoes the same maximum effective angle of attack, a wake diffusion spectrum aligns with the Betz limit threshold. Crucially, the closeness to this efficiency frontier suggests a universal maximum effective angle of attack—a consistent law that remains valid for the conventional flapping turbine design. It implies that selections for stroke and pitch amplitudes should be methodical rather than arbitrary. In addition, the positioning of the pitch axis ought to be modified in tandem with phase difference adjustments to bolster the synchronization between heaving motions and resultant lift. The ideal phase difference is variable, contingent on pitch amplitude and pitch axis position. Even with low pitch amplitudes, fine-tuning the phase difference guarantees that the energy harvesting efficiency does not fall below 30%. Such an enhancement would significantly broaden the operational envelope and the parameter space for flapping turbines.

Modeling the Simultaneous Dropout of Energetic Electrons and Protons by Magnetopause Shadowing

AbstractMagnetopause shadowing (MPS) effect could drive a concurrent dropout of radiation belt electrons and ring current protons. However, its relative role in the dropout of both plasma populations has not been well quantified. In this work, we study the simultaneous dropout of MeV electrons and 100s keV protons during an intense geomagnetic storm in May 2017. A radial diffusion model with an event‐specific last closed drift shell is used to simulate the MPS loss of both populations. The model well captures the fast shadowing loss of both populations at L* > 4.6, while the loss at L* < 4.6, possibly due to the electromagnetic ion cyclotron wave scattering, is not captured. The observed butterfly pitch angle distributions of electron fluxes in the initial loss phase are well reproduced by the model. The initial proton losses at low pitch angles are underestimated, potentially also contributed by other mechanisms such as field line curvature scattering.

Characterising the effects of geometry on the natural convection heat transfer in closed even-span gable-roof greenhouses

Over the years, researchers have attempted to reduce the heat loss that arises from the natural convection in confined even-span gable-roof greenhouses due to the temperature difference between the floor and the walls (particularly at night and during winter). However, the effect that the geometry of these greenhouses has on this natural convection does not appear to have been systematically investigated.To address this, this study examined the influence of aspect ratio and roof pitch of greenhouses on the natural convection inside them. In this vein, a numerical model was developed using computational fluid dynamics (CFD) and validated against experimental data. It was found that decreasing the aspect ratio and roof pitch typically reduced the natural convection heat transfer, with changes of up to 25% for aspect ratios and 15% for roof pitch angles being observed. This suggests that a low-profile greenhouse with a low roof pitch offered the best opportunity for reducing heat loss. That said, under some conditions a multicellular flow regime can occur, and this leads to an increase in the heat transferred from the greenhouse. Hence, the choice of aspect ratio and roof pitch angle require careful consideration.Finally, a parametric relationship was developed to assist greenhouse designers determine their heat loss for a range of greenhouse geometries. Designers of greenhouses are encouraged to take advantage of the proposed relationship to develop model-based control strategies that minimize supplementary heating and deliver energy efficient greenhouses into the future.

Performance and Acoustics of a Stacked Rotor with Differential Collective Pitch

Performance and acoustics of a 1.108-m radius stacked rotor in hover with an axial spacing between the upper and lower rotors of 0.73 chords were measured. The differential collective pitch of the rotor system, de ned as half the difference between the upper rotor pitch and lower rotor pitch was varied along with the azimuthal spacing between the upper and lower blade sets. Coupled comprehensive analysis and acoustics simulations were conducted using the Rotorcraft Comprehensive Analysis System, the acoustic solver PSU-WOPWOP, and the Brooks, Pope, and Marcolini method implemented in ANOPP2. Increased sensitivity to azimuthal spacing was measured for large, negative differential collectives, resulting in a 76.5% change in total rotor thrust and a 46% change in total rotor power over 11.25 ° change in azimuthal spacing. The trends in individual and total system thrust were predicted with good accuracy, but the total power was overpredicted. Overall sound pressure level decreased by 3.5 dB at – 2° differential collective and 90° azimuthal spacing due to reduced broadband levels, indicating a possible quiet mode of operation for this type of rotor. By assessing the highest performance and lowest noise, an optimum rotor con guration was observed at an azimuthal spacing of – 45° and differential collective of 2°. Acoustic predictions captured tonal and broadband noise trends in most conditions. Conditions where broadband noise was underpredicted could be a result of vortex interactions not modeled by the broadband simulations.

Speed of Pitch Change in People with Parkinson’s Disease: A Pilot Study

Objective. To examine laryngeal maximum performance through a novel pitch diadochokinetic (DDK) task in people with Parkinson’s disease (PD) and healthy controls. Methods. This exploratory pilot study included a total of eight people with PD (seven male and one female) and eight healthy controls. Participants were instructed to rapidly transition or alternate between a chosen comfortable low and high pitch and were instructed to complete the task as a pitch glide. An Auditory Sawtooth Waveform Inspired Pitch Estimator-Prime model was used to first extract the pitch contour and then a customized MATLAB algorithm was used to compute and derive measures of pitch range and pitch slope. Results. Pitch range and slope were reduced in some participants with PD. Effects of age and disease duration were observed in people with PD: reductions in both pitch measures with increase in age and disease duration. Conclusions. A novel pitch DDK task may supplement the conventional laryngeal DDK task in the evaluation and treatment of motor speech and voice disorders. Individual variability analysis may provide specific diagnostic and therapeutic insights for people with PD.