High Pitch Research Articles

The Annoying Nature of Snoring Sounds Is Not Only about Intensity: A Pilot Study on Exposed Test Subjects.

This study aims to assess (i) which acoustic characteristics of snoring sounds are associated with the annoying nature of snoring sounds; (ii) whether listeners' heart rates correlate with their perceived annoyance; and (iii) whether perceived annoyance is different between listeners with different experiences with their bedpartners' snoring sounds. Six snoring epochs with distinct acoustic characteristics (viz., reference, high pitch, high intensity, short interval, irregular intensity, and irregular intervals) were collected from snoring patients. Twenty physicians and technicians were involved in the healthcare of snoring patients, and were divided into three groups based on personal experience with their bedpartners' snoring sounds (viz., non-snoring, snoring but not annoying, and snoring and annoying). The test subjects listened to each epoch and rated its level of annoyance. Listeners' heart rates were also recorded during the test using a finger plethysmograph. Within the limitations of this study, it was found that, compared with other snoring sounds, snoring sounds with high intensity and irregularity were associated with higher perceived annoyance. However, higher perceived annoyance of snoring sound was not reflected in heart rate-related parameters. In addition, listeners' personal experiences do not seem to affect their perceived annoyance.

Differences in Glottal Closure and Visibility of the Anterior Commissure during Rigid-90°, Rigid-70°, and Flexible Laryngostroboscopy

Introduction: The conventional rigid-90° and rigid-70° laryngostroboscopy has been so far considered the gold standard in assessing the vibratory behavior of the vocal folds and the glottal closure configuration during phonation. Meanwhile, this rigid laryngostroboscopy is more and more replaced by flexible chip-on-tip systems. The aim of this study was to evaluate the influence of these different endoscopic techniques on glottal closure configuration and on visibility of the complete focal fold length including anterior commissure during phonation. Methods: Twenty-one euphonic subjects were enrolled (mean age 34.6 ± 9.5; m = 10, f = 11). They were examined with the three laryngoscopic techniques (conventional rigid-90°, rigid-70°, and flexible chip-on-tip laryngoscopy during low and high voice pitch with soft and loud voice intensity). For evaluating the degree of glottal closure, a modified classification of Södersten et al. was applied and the visibility of the anterior commissure was evaluated. The correlation of the three endoscopic techniques was assessed with Cohen and Fleiss’ kappa. Results: In even low loud phonation, the rigid-90° and rigid-70° endoscopies revealed a complete closure of the glottis in only 47.6% of subjects but with flexible endoscopy in 81%. The complete vocal fold length with anterior commissure was best visible with flexible endoscopy in 90.5% in low-soft and high-soft phonation. The rigid-90° endoscopy showed a slight agreement in comparison with the flexible endoscopy in regard to the types of vocal fold closure with a Cohen’s kappa coefficient k = 0.199. The rigid-90° endoscopy showed an almost perfect agreement with k = 0.84 when compared to the rigid-70° endoscopy. The flexible endoscopy compared to the rigid-70° endoscopy showed a fair agreement with k = 0.346. Conclusion: We found mainly corresponding results in both rigid-90° and rigid-70° endoscopic techniques which can be explained by the same transoral approach with the tongue pulled out, whereas the flexible transnasal endoscopy mainly gives a better view on the anterior commissure. The influence of transorally or transnasally guided endoscopic techniques needs to be considered in interpretation of laryngostroboscopic parameters like vocal fold closure and supraglottal hyperactivity.

Performance evaluation of serpentine tube coupled with modified twisted tapes utilized as heat extraction coil in solar ponds

The thermal energy collected and stored by solar ponds is usually extracted by using some heat exchangers, where curved tubes form their core. The present study aims to appraise the performance of a serpentine tube under varied mass flow rates and inlet temperatures of the working fluid. Three different types of twisted tapes nominated as uniform twist pitches (U), low to high twist pitches (LH), and high to low twist pitches (HL) are employed to enhance the heat extraction rate. This article is the first report addressing the application of non-uniform twisted tapes as turbulators in a serpentine tube. In this regard, a solar pond simulator containing salt water is designed and fabricated. Numerical simulations are also carried out to display the transport phenomena inside the models. The numerical results are compared with the experimental data, and a close agreement is found. From the thermal point of view, the sequence of twisted tapes is LH > HL > U, while it follows the order of U > LH > HL according to the frictional loss. The findings demonstrate that depending on operating conditions, the heat extracted by the modified cases is 4 to 70% more than the base model. It is also found that employing non-uniform twisted tapes results in lower flow resistance compared to the uniform case. The pressure drop augmentations produced by U, LH, and HL TTs are 26.5%, 17.5%, and 10.4%. Further, the overall performance index is higher than unity for all the enhanced cases. The best case is the twisted tape having low to high twist pitches (LH) which has an average performance index from 2.03 to 2.71.

HeadPose-Softmax: Head pose adaptive curriculum learning loss for deep face recognition

Face recognition has been one of the most popular applications in the field of target detection. Currently, frontal faces can be easily detected, but multi-view face detection remains a difficult task because of various factors such as illumination, various poses, occlusions, and facial expressions. Margin-based loss functions are used to increase the feature margins between different classes, thus enhancing the discriminability of face recognition models, but the performance in face detection in complex scenes (e.g., high pitch angle face detection in surveillance environments) can be significantly degraded. Recently, the idea of a mining-based strategy to emphasize hard samples has been used to achieve good results in multi-view face detection. However, most of the existing methods do not explicitly emphasize samples based on their importance, resulting in the underutilization of hard samples. In this paper, we propose a curriculum learning loss function (HeadPose-Softmax) to classify the difficulty of a sample based on its facial pose, and embed the concept of curriculum learning into the loss function to implement a novel training strategy for deep face recognition. The loss function explicitly emphasizes the importance of the samples according to the different difficulty of each sample, which allows the model to make fuller use of hard samples, focus on learning pose invariant features, and improve the accuracy of the model in multi-view face detection tasks. Specifically, our HeadPose-Softmax dynamically adjusts the relative importance of the hard samples according to the pose angle of the face in the hard samples during the training phase. At each stage, different samples are assigned different importance according to their corresponding difficulty. Extensive experimental results under popular benchmarks show that our HeadPose-Softmax can enhance the accuracy of the model in multi-view face detection and outperform the state-of-the-art competitors.

First measurements of a scintillator-based fast-ion loss detector in reversed Ip/Bt at the ASDEX Upgrade tokamak

Fast-α losses in future fusion power plants are expected to follow the co- and counter-current directions due to the isotropy of the fusion reaction. At the ASDEX Upgrade tokamak, the co-current direction (achieved with positive plasma current and negative toroidal magnetic field) has been extensively studied thanks to an array of five fast-ion loss detectors (FILD). A new fast-ion loss detector compatible with reversed Ip/Bt (negative plasma current and positive magnetic toroidal field, defining positive as counter-clockwise when the machine is viewed from the top), namely RFILD, has been designed and commissioned to study the behaviour of counter-current fast-ion losses and to expand our knowledge on QH-mode, I-mode, and the L-H transition. The detector is a modified version of the midplane manipulator fast-ion loss detector that features a new probe head orientation and collimator geometry, optimised using the FILDSIM code. A fast CMOS camera is used as a high spatial resolution acquisition system, while an array of photomultipliers (up to 1 MHz) serves as a fast channel.First measurements have been taken in I-mode, QH-mode, L-mode and H-mode with core densities ranging between 4·1019 and 9·1019 m−3, IP between -0.8 and -0.6 MA and Bt of 2.5 T approximately. NBI fast-ion losses were observed for the first time in reversed Ip/Bt, producing high pitch (60 – 80°) losses. ICRH losses in H-minority heating configuration have also been observed in I-mode experiments. These losses correspond to the outer leg of banana particle trajectories. An upgraded double collimator detector design is also presented, that will increase the measurable particle range in future experimental campaigns (co- and counter-current particles simultaneously). Thus, we expand our understanding on the mechanisms behind fast-ion losses at the ASDEX Upgrade tokamak in the reversed Ip/Bt configuration.

Funkční hodnocení laryngoskopického vyšetření a souvislost s kvalitou hlasu a parametry hlasového pole

Summary Introduction: Previous laryngoscopy evaluation protocols have mostly focused on assessment of glottal status and morphological description of vocal folds’ shape and oscillations. The basic functional manifestations of laryngeal use, according to new protocols, include a description of supraglottic laryngeal activity. Methods: Laryngoscopic evaluation was performed as a perceptual test, performed online, using a web-based application. The degree and type of glottal insufficiency and the degree of anterior, posterior compression and lateral-medial (L-M) compression separately for each side were evaluated by a total of 15 respondents in a total of 26 video recordings of laryngoscopic examinations. In addition, the correlations between listening evaluations of the voice using modified GRBAS scales and voice range profile parameters were investigated. Results: The ratings of the laryngoscopic scales had well to excellent agreement. Agreement for type of insufficiency was just moderate. The associated ratings of L-M compression on the right and left sides showed correlations. For listening evaluation, medial compression was found to be related to the perception of habitual voice strain, and to strain and instability in the pitch range of the change of registers of the singing voice. Degree of insufficiency predicted less fullness of habitual voice in general but was also related to vocal dyspnea and weakness when calling. At the same time, it was largely responsible for the deterioration of the quality of the singing voice. Medial compression systematically reduced pitch range and the area of the voice range profile. Conclusion: The results of the perceptual evaluation can be used in further education. On their basis, didactic material for training the assessment of supraglottic laryngeal activity was prepared and published in the form of an online tutorial. The degree of insufficiency generally affects various characteristics of the speaking and singing voice. Medial compression systematically affects only the strain of the speaking voice, while in the singing voice it accentuates the strain and instability of the transitional region between registers and impairs the production of high pitches. Key words laryngoscopy – visual evaluation – voice range profile – GRBAS

The prosody of surprise questions in Estonian

This paper examines the role of prosody in a little-studied type of non-canonical questions: syntactically and lexically canonical interrogative sentences that have been uttered by the speaker in order to express surprise. The study compares Estonian surprise questions with string-identical information-seeking questions elicited by means of context descriptions. The materials comprise 1,008 utterances by 21 speakers.It is concluded that the prosody of the examined utterances has three roles that are relevant to the expression of surprise by ordinary interrogative sentences. First, the enhanced prosodic realisation of the utterances as manifested in a longer duration, a wider pitch range, and a more frequent occurrence of upstepped pitch accents conveys emotional expressivity. Second, lower pitch along with the creaky voice quality signals that the utterances are not canonical questions, while the main prosodic correlate of information-seeking questions is high pitch. Phonological pitch accents and boundary tones, however, are not used to distinguish between surprise questions and information-seeking questions. Third, the nuclear accent placement signals an information structure that is associated with the expression of incongruity or counterexpectation: the focal accent can evoke an alternative (set) that arises from the speaker’s expectations.

Swallow Impairment in Parkinson's Disease: Revelations from High-Resolution Videomanometry.

Parkinson's disease (PD) is a degenerative disorder that can cause dysphagia and dysphonia. We studied upper esophageal sphincter (UES) function and vocal tests using high-resolution videomanometry (HRVM) in PD. Ten healthy volunteers and 20 patients with PD performed swallowings (5ml and 10ml) and vocal tests using HRVM synchronized to the vocal acoustic recording. Mean age of the Parkinson group was 68.7 ± 9.7years and mean disease stage of 2.7 ± 1.1 (Hoehn & Yahr scale). In videofluoroscopy swallow study (VFSS) for 5ml, laryngeal elevation was significantly reduced (p = 0.01) in PD and for 10ml, anteriorization (p = 0.03), elevation (p = 0.03) and total displacement (p = 0.05) were reduced in PD. In high-resolution manometry (HRM) for both volumes, intrabolus pressure was significantly higher in PD (p = 0.0004 and p = 0.001) and a higher NADIR UES relaxation pressure and NADIR UES relaxation at pharyngeal peak contraction in PD (p = 0.00007 and p = 0.0003, p = 0.01 and p = 0.04), respectively. Vocal tests results showed differences between the groups, especially for larynx anteriorization with high pitch /a/ emission (p = 0.06) in VFSS and for UES length with high pitch /i/ with tongue protrusion (p = 0.07) in HRM. Our results demonstrated a reduced compliance and subtle changes in UES function in early and moderate PD stage. We also demonstrated using HRVM that vocal tests can affect UES function. The use of HRVM proved to be an important tool in the description of events related to phonation and swallowing, which can affect the rehabilitation of patients with PD.

Exploring macro-rhythm in African American English

This study contributes to a growing body of research on quantifying the theory of macro-rhythm, a model of prosodic typology proposed by Sun-Ah Jun (2014) that looks at the global pitch patterns of an utterance, through comparing African American English (AAE) to Mainstream (white) US English (MUSE). Based on prior research on intonation, rhythm, and prosody in AAE (cf. Thomas, 2015 for a thorough overview), we predicted that AAE would have stronger macro-rhythm than MUSE, such that speakers would produce higher peaks and lower valleys, pitch excursions of greater magnitude, have a greater consistency in slope, a greater frequency of high (H) and low (L) pitch targets, and more regular spacing of these pitch targets. Data weretaken from the Valdosta group of the Corpus of Regional African American Language (CORAAL) for Black speakers and the Buckeye corpus for white speakers. Contrary to our expectations, Buckeye speakers proved to be more macro-rhythmic than their CORAAL counterparts in all but one metric, but these results confirm that macro-rhythm is a viable method for cross-dialectal analysis as it reveals quantifiable differences between speaker dialect groups of the same language.

Persistent subjective voice symptoms for two years after thyroidectomy

BackgroundVoice change after thyroidectomy is an important issue in thyroid surgery. However, little is known about long-term voice outcomes after thyroidectomy. This study investigates the long-term voice outcomes of thyroidectomy up to two years after surgery. Also, we analyzed the pattern of recovery through acoustic tests over time. MethodsWe reviewed data from 168 patients who underwent thyroidectomy between January 2020 and August 2020 at a single institution. The Thyroidectomy-related Voice and Symptom Questionnaire (TVSQ) score and acoustic voice analysis results were examined preoperatively and postoperative one, three, and six months, and one and two years after surgery. We divided patients into two groups based on the TVSQ score (≥15 or <15) at two years postoperatively. We investigated the difference of acoustic characteristics between the two groups and analyzed correlations between acoustic parameters and various clinical and surgical factors. ResultsVoice parameters tended to recover, but some parameters and TVSQ scores exhibited deterioration two years after surgery. In the subgroups, among the many clinicopathologic factors examined, voice abuse history including professional voice users (p = 0.014), greater extent of thyroidectomy and neck dissection (p = 0.019, p = 0.029), and high pitch voice (F0; p = 0.005, SFF; p = 0.016) were associated with high TVSQ score at two years. ConclusionsPatients frequently experience voice discomfort after thyroidectomy. After surgery, voice abuse history including professional voice users, greater extent of surgery, and higher pitch voice are associated with worse voice quality and increased risk of persistent voice symptoms over the long-term.

Acoustic properties of chimpanzee pant-hoots reflect male mate quality

Sexual selection theory predicts that acoustic structure may provide cues of individual traits correlated with mate quality. Chimpanzee pant-hoots are complex, conspicuous calls that may be products of sexual selection. Insofar as pant-hoots are difficult to produce, requiring individuals to approach their physiological limits of sound production, they may serve as honest signals of physical condition. The highest pitch elements in pant-hoots appear the most difficult elements to produce, as they sometimes exhibit distortions in acoustic structure known as non-linear phenomena (NLP). Producing high pitch vocalizations with fewer NLPs may, thus, signal superior physical condition. We examined whether the proportion of NLPs, the pitch, and noise in these elements of the pant-hoots contain cues of mate quality including age, rank, and a measure of health (infection with the simian immunodeficiency virus, SIVcpz), and if they predict male mating success. Consistent with predictions from sexual selection, we found that (i) the proportion of NLPs was associated with age in a non-linear fashion—specifically, subadult and old males exhibited higher proportions of NLPs compared to males in their prime mating age; (ii) a lower proportion of NLPs predicted higher mating success; and (iii) SIVcpz positive individuals exhibited more noise in their pant-hoots.

Intrinsic velocity differences between larynx raising and larynx lowering.

In this study, 23 subjects produced cyclic transitions between rounded vowels and unrounded vowels as in /o-i-o-i-o-…/ at two specific speaking rates. Rounded vowels are typically produced with a lower larynx position than unrounded vowels. This contrast in vertical larynx position was further amplified by producing the unrounded vowels with a higher pitch than the rounded vowels. The vertical larynx movements of each subject were measured by means of object tracking in laryngeal ultrasound videos. The results indicate that larynx lowering was on average 26% faster than larynx raising, and that this velocity difference was more pronounced in woman than in men. Possible reasons for this are discussed with a focus on specific biomechanical properties. The results can help to interpret vertical larynx movements with regard to underlying neural control and aerodynamic conditions, and to improve movement models for articulatory speech synthesis.

Motherese in Omani Arabic

Motherese, alternatively known as parentese, infant directed speech, or baby talk, is the spontaneous emotive manner in which mothers converse with their newborns and young children to establish mother-child communication. The occurrence of motherese in mother-child communication is attested cross-linguistically with variant extent and frequency in languages and cultures of the globe. Due to its distinct linguistic features that tease it out from adult directed speech, it is believed to have a positive role in facilitating and accelerating children’s acquisition of their mother tongue. Prominent linguistic features that characterize motherese are often the use of simplified constructions, specific lexical items intentionally meant for children, higher pitch, slower tempo, and prolonged pronunciation, among several other ones. The role these features play in enhancing children’s exposure to and comprehension of their mother tongue as well as the establishment of a compassionate mother-child relationship stand as the driving force behind its use by mothers from different walks of life cross-culturally. The Arab culture is not an exception to this tendency since motherese is attested in several varieties of Arabic. Omani Arabic as one member of these varieties does have motherese in its daily use; yet, it is not brought to light. In an attempt to sightsee such untraversed area and bring it to light, this paper is, thus, a humble endeavor to investigate the practice of using motherese among Omani mothers and children to establish mother-child communication. Results show that several features characterize Omani Arabic motherese, those that may conform to or differ from features that characterize baby talk in other languages and cultures.

The effect of Wendler Glottoplasty to elevate vocal pitch in transgender women

Objective: To evaluate the effect of Wendler Glottoplasty to elevate vocal pitch in transgender women. Methods: The voice parameters of pre-and 3-month post-surgery of 29 transgender women who underwent Wendler Glottoplasty in department of otorhinolaryngology head and neck surgery of Beijing Friendship Hospital from January, 2017 to October, 2020 were retrospectively analyzed. The 29 transgender women ranged in age from 19-47 (27.0±6.3) years old. Subjective evaluation was performed using Transsexual Voice Questionnaire for Male to Female (TVQMtF). Objective parameters included fundamental frequency (F0), highest pitch, lowest pitch, habitual volume, Jitter, Shimmer, maximal phonation time (MPT), noise to harmonic ratio (NHR) and formants frequencies(F1, F2, F3, F4). SPSS 25.0 software was used for statistically analysis. Results: Three months after surgery, the score of TVQMtF was significantly decreased [(89.9±14.7) vs. (50.4±13.6), t=11.49, P<0.001]. The F0 was significantly elevated [(152.7±23.3) Hz vs. (207.7±45.9) Hz, t=-6.03, P<0.001]. Frequencies of F1, F2 and F3 were significantly elevated. No statistical difference was observed in the frequencies of F4. The highest pitch was not significantly altered while the lowest pitch was significantly elevated [(96.8±17.7) Hz vs. (120.0±28.9) Hz, t=-3.71, P=0.001]. Habitual speech volume was significantly increased [(60.0±5.2) dB vs. (63.6±9.6) dB, t=-2.12, P=0.043]. Jitter, Shimmer, NHR and MPT were not obviously altered (P>0.05). Conclusions: Wendler Glottoplasty could notably elevate the vocal pitch, formants frequencies and degree of vocal femininity in transgender women without affecting phonation ability and voice quality. It can be an effective treatment modality for voice feminization.

Kinematic Optimization of Energy Extraction Efficiency for Flapping Airfoil by using Response Surface Method and Genetic Algorithm

In this paper, numerical simulations have been performed to study the performance of a single fully activated flapping wing serving as energy harvester. The aims of the paper are predicting and maximizing the energy extraction efficiency by using optimization methodology. The metamodeling and the genetic algorithms are applied in order to find the optimal configuration improving the efficiency. A response surface method (RSM) based on Box–Behnken experimental design and genetic algorithm has been chosen to solve this problem. Three optimization factors have been manipulated, i.e. the dimensionless heaving amplitude h0, the pitching amplitude θ0 and the flapping frequency f. The ANSYS FLUENT 14 commercial software has been used to compute the governing flow equations at a Reynolds number of 1100, while the flapping movement combined from heaving and pitching of the NACA0015 foil has been carried out by using an in house user-defined function (UDF). A maximum predicted efficiency of 34.02% has been obtained with high accuracy of optimal kinematic factors of dimensionless heaving amplitude around the chord, high pitching amplitude and low flapping frequency of 0.304 hertz. Results have also showed that the interaction effect between optimization factors is important and the quadratic effect of the frequency is strong confirming the great potential of the applied optimization methodology.

Most high school baseball pitchers are using weighted ball throwing programs to increase ball velocity: crosssectional analysis of US high school pitchers

Weighted-ball velocity training programs are popular but may be associated with increased injury risk. The purpose of this study was to determine the current frequency of these programs, as well as their association with range of motion, strength, velocity, injury, and utilization in high school baseball pitchers. This was a multicenter, prospective, community-based study including high schools from the Northeastern, Southeastern, Midwestern, and Western regions of the United States. Preseason pitchers were surveyed about their use of weighted ball velocity programs and history of injury. Preseason pitchers underwent standardized physical examinations and pitch velocity was measured. During a single high school season, pitch counts and injury incidence were prospectively collected. In total, 115 pitchers were recruited, of whom 63% had participated in a weighted ball program. There were no differences in range of motion or strength between groups who used weighted balls and those who did not. Pitchers that utilized weighted ball programs demonstrated a higher average fastball velocity (114.26 vs. 106.22 km/h [71 vs. 66 mph]; P < .001) as well as peak fastball velocity (115.87 vs. 109.44 km/h [72 vs. 68 mph]; P= .001) compared to those that did not use weighted ball programs. Pitchers that utilized weighted ball programs were no more likely to be single-sport athletes (44%) than those who were multisport athletes (49%, P= .667). Within the group who had used a weighted ball program 29% (13/45) reported a history of injury and within the group who had not used a weighted ball program 25% (10/40) reported a history of injury (P= .687). As only a single injury occurred in the entire cohort, comparison of injury rates could not be completed. In this prospective study, the majority of high school pitchers reported using weighted ball programs to increase velocity, and these programs were associated with increased average and peak velocity compared to pitchers who did not use weighted ball programs. There were no significant differences in injury history between the 2 groups. Further study is necessary to understand the injury risk associated with weighted ball programs.

Synchrotron Firehose Instability

We demonstrate using linear theory and particle-in-cell (PIC) simulations that a synchrotron-cooling collisionless plasma acquires pressure anisotropy and, if the plasma beta is sufficiently high, becomes unstable to the firehose instability, in a process that we dub the synchrotron firehose instability (SFHI). The SFHI channels free energy from the pressure anisotropy of the radiating, relativistic electrons (and/or positrons) into small-amplitude, kinetic-scale, magnetic-field fluctuations, which pitch-angle scatter the particles and bring the plasma to a near-thermal state of marginal instability. The PIC simulations reveal a nonlinear cyclic evolution of firehose bursts interspersed by periods of stable cooling. We compare the SFHI for electron–positron and electron–ion plasmas. As a byproduct of the growing electron-firehose magnetic-field fluctuations, magnetized ions gain a pressure anisotropy opposite to that of the electrons. If these ions are relativistically hot, we find that they also experience cooling due to collisionless thermal coupling with the electrons, which we argue is mediated by a secondary ion-cyclotron instability. We suggest that the SFHI may be activated in a number of astrophysical scenarios, such as within ejecta from black hole accretion flows and relativistic jets, where the redistribution of energetic electrons from low to high pitch angles may cause transient bursts of radiation.

OVERLAP TYPES IN GOLDEN GLOBE AWARD INTERVIEW BY THE HOLLYWOOD REPORTER

The aim of this research is to categorize what types of overlap are constructed in Golden Globe Award Interview 2020 with Nicholas Braun by The Hollywood Reporter. In an interview, it is one of turn taking violations which still becomes a rife phenomenon where many speakers aren’t aware yet about it. The approach used in this research is descriptive qualitative by documentation technique. The main theory of overlap types is based on Schegloff (2000) and French &amp; Local (1983). There are 13 data found which contain 11 non-competitive: 1 terminal overlap, 5 continuers, 4 conditional access to the turn, 1 choral and 2 competitive: 2 high pitch and increased loudness. So, it can be concluded that the most dominant of overlap type is continuers that categorized as unproblematic for the speakers and conversation structure. Because the next speakers used it to respect the current speakers. Therefore, this result is expected as one of overlap examples which can be applied.

Optimization of smoothing factor for fast non-local means algorithm in high pitch based low-dose computed tomography images with tin-filter

In this study, we applied the fast non-local means (FNLM) algorithm to high-pitch low-dose computed tomography (CT) images using a tin-filter. This study was conducted via a simulation study using a Shepp-Logan phantom and an experimental approach using American association of physicists in medicine (AAPM) phantom images. To optimize the smoothing factor of the FNLM algorithm, the values were adjusted from 0.01 to 0.05 at intervals of 0.001 and applied to the CT image. The smoothing factor of the optimal FNLM algorithm, derived through various quantitative evaluations, was 0.03. According to the results, when the optimized FNLM algorithm was applied to the acquired CT image with a low-dose protocol based on a high pitch condition, the estimated coefficient of variation, contrast-to-noise ratio, and signal-to-noise ratio were improved by 8.7, 6.7, and 8.0 times, respectively, compared to the general CT scanning condition (none). In addition, compared with the noise filtering methods mainly used in the past, both simulation and real experimental results proved that the application efficiency of the FNLM algorithm was high in the obtained low-dose-based CT images. In summary, the applicability of the FNLM algorithm in CT images obtained under low-dose conditions with high pitch using a tin-filter was demonstrated, and the derived research results are expected to be actively utilized in the diagnostic medical field to help reduce exposure doses and improve image quality.

Lattice Boltzmann Modeling of Cholesteric Liquid Crystal Droplets Under an Oscillatory Electric Field

We numerically study the dynamics of quasi-two dimensional cholesteric liquid crystal droplets in the presence of a time-dependent electric field, rotating at constant angular velocity. A surfactant sitting at droplet interface is also introduced to prevent droplet coalescence. The dynamics is modeled following a hybrid numerical approach, where a standard lattice Boltzmann technique solves the Navier-Stokes equation and a finite difference scheme integrates the evolution equations of liquid crystal and surfactant. Our results show that, once the field is turned on, the liquid crystal rotates coherently triggering a concurrent orbital motion of both droplets around each other, an effect due to the momentum transfer to the surrounding fluid. In addition the topological defects, resulting from the conflict orientation of the liquid crystal within the drops, exhibit a chaotic-like motion in cholesterics with a high pitch, in contrast with a regular one occurring along circular trajectories observed in nematics drops. Such behavior is found to depend on magnitude and frequency of the applied field as well as on the anchoring of the liquid crystal at the droplet interface. These findings are quantitatively evaluated by measuring the angular velocity of fluid and drops for various frequencies of the applied field.