Link between triglyceride-glucose-body mass index and future stroke risk in middle-aged and elderly chinese: a nationwide prospective cohort study.

OBJECTIVE: Current literature is deficient in robust evidence delineating the correlation between the triglyceride glucose-body mass index (TyG-BMI) and the incidence of stroke. Consequently, this investigation seeks to elucidate the potential link between TyG-BMI and stroke risk in a cohort of middle-aged and senior Chinese individuals. METHODS: This study employs longitudinal data from four waves of the China Health and Retirement Longitudinal Study (CHARLS) conducted in 2011, 2013, 2015, and 2018, encompassing 8,698 participants. The CHARLS cohort was assembled using a multistage probability sampling technique. Participants underwent comprehensive evaluations through standardized questionnaires administered via face-to-face interviews. Our analytic strategy involved the application of Cox proportional hazards regression models to investigate the association between TyG-BMI and the risk of stroke. To discern potential non-linear relationships, we incorporated Cox proportional hazards regression with smooth curve fitting. Additionally, we executed a battery of sensitivity and subgroup analyses to validate the robustness of our findings. RESULTS: Our study utilized a multivariate Cox proportional hazards regression model and found a significant correlation between the TyG-BMI and the risk of stroke. Specifically, a 10-unit increase in TyG-BMI corresponded to a 4.9% heightened risk of stroke (HR = 1.049, 95% CI 1.029-1.069). The analysis also uncovered a non-linear pattern in this relationship, pinpointed by an inflection point at a TyG-BMI value of 174.63. To the left of this inflection point-meaning at lower TyG-BMI values-a 10-unit hike in TyG-BMI was linked to a more substantial 14.4% rise in stroke risk (HR 1.144; 95% CI 1.044-1.253). Conversely, to the right of the inflection point-at higher TyG-BMI values-each 10-unit increment was associated with a smaller, 3.8% increase in the risk of stroke (HR 1.038; 95% CI 1.016-1.061). CONCLUSIONS: In the middle-aged and elderly Chinese population, elevated TyG-BMI was significantly and positively associated with stroke risk. In addition, there was also a specific non-linear association between TyG-BMI and stroke (inflection point 174.63). Further reduction of TyG-BMI below 174.63 through lifestyle changes and dietary control can significantly reduce the risk of stroke.

Repeatability and reproducibility comparisons of liver IVIM imaging with free-breathing or respiratory-triggered sequences.

For liver intravoxel incoherent motion (IVIM) data acquisition, respiratory-triggering (RT) MRI is commonly used, and there are strong motivations to shorten the scan duration. For the same scan duration, more b values or higher numbers of excitations can be allowed for free-breathing (FB) imaging than for RT. We studied whether FB can be used to replace RT when careful IVIM image acquisition and image processing are conducted. MRI data of 22 healthy participants were acquired using a 3.0 T scanner. Diffusion imaging was based on a single-shot spin-echo-type echo-planar sequence and 16 b values of 0, 2, 4, 7, 10, 15, 20, 30, 46, 60, 72, 100, 150, 200, 400, and 600 s/mm2 . Each subject attended two scan sessions with an interval of 10-20 days. For each scan session, a subject was scanned twice, first with RT and then with FB. The mean image acquisition time was 5.4 min for FB and 10.8 min for RT. IVIM parameters were calculated with bi-exponential model segmented fitting with a threshold b value of 60 s/mm2 , and fitting started from b = 2 s/mm2 . There was no statistically significant difference between IVIM parameters measured with FB imaging or RT imaging. Perfusion fraction ICC (intraclass correlation coefficient) for FB imaging and RT imaging in the same scan session was 0.824. For perfusion fraction, wSD (within-subject standard deviation), BA (Bland-Altman) difference, BA 95% limit, and ICC were 0.022, 0.0001, -0.0635~0.0637, and 0.687 for FB and 0.031, 0.0122, -0.0723~0.0967, and 0.611 for RT. For Dslow (×10-3  s/mm2 ), wSD, BA difference, BA 95% limit, and ICC were 0.057, 0.0268, -0.1258~0.1793, and 0.471 for FB and 0.073, -0.0078, -0.2170-0.2014, and <0.4 for RT. The Dfast coefficient of variation was 0.20 for FB imaging and 0.28 for RT imaging. All reproducibility indicators slightly favored FB imaging.

Relationship between glycated hemoglobin levels and three-month outcomes in acute ischemic stroke patients with or without diabetes: a prospective Korean cohort study.

OBJECTIVE: In patients experiencing acute ischemic stroke, there is ongoing debate surrounding the connection between chronic hyperglycemic status and their initial clinical outcomes. Our objective was to examine the connection between glycated hemoglobin (HbA1c) levels and adverse clinical outcomes at both 3-months adverse clinical outcomes in individuals with acute ischemic stroke (AIS) with and without diabetes. METHODS: The present prospective cohort study involved 896 AIS patients without diabetes and 628 with diabetes treated at a South Korean hospital from January 2010 to December 2016. The target independent variable is HbA1c. The outcome variable is a modified Rankin scale score ≥ 3. A binary logistic regression model was applied to assess the connection between HbA1c levels and 3-month poor clinical outcomes in AIS patients with and without diabetes. Additionally, a generalized additive model and smoothed curve fitting were utilized to explore potential nonlinear associations between HbA1c levels and 3-month adverse clinical outcomes in AIS patients with and without diabetes. RESULTS: The binary logistic regression model could not identify any statistically significant connection between HbA1c and 3-month adverse clinical outcomes in AIS patients, both those with and without diabetes, after correcting for various factors. However, a nonlinear relationship emerged between HbA1c and 3-month adverse clinical outcomes in AIS patients with diabetes. The inflection point for HbA1c was determined to be 6.1%. For HbA1c values ≤ 6.1%, an inverse association was observed between HbA1c and 3-month adverse clinical outcomes in diabetic AIS patients, and each 1% increase in HbA1c in AIS patients with DM was associated with an 87% reduction in 3-month adverse clinical outcomes (OR = 0.13, 95% CI: 0.02-0.81). Conversely, when HbA1c exceeded 6.1%, a positive association between HbA1c and 3-month adverse clinical outcomes became apparent in diabetic AIS patients, and each 1% increase in HbA1c in AIS patients with DM was associated with a 23% increase in 3-month adverse clinical outcomes (OR = 1.23, 95%CI: 1.03-1.47). However, it's important to note that no significant linear or nonlinear relationships were observed between HbA1c levels and 3-month adverse clinical outcomes in AIS patients without diabetes. CONCLUSION: Our findings suggest a nonlinear connection and threshold effect between HbA1c and 3-month adverse clinical outcomes in AIS patients with diabetes. AIS patients with diabetes had a lower risk of 3-month adverse clinical outcomes when their HbA1c control was close to 6.1%. Our findings may aid treatment decision-making and potentially guide interventions to optimize glycemic control in AIS patients.

The Changes in Relative Blood Volume during Dialysis Are Characterized by Ultrafiltration Rate and Predialysis Blood Test Values.

INTRODUCTION: Continuous monitoring of relative blood volume (percentage BV) in hemodialysis (HD) is critical for determining dry weight and preventing intradialytic hypotension. However, the cause of the BV variation remains unknown. This research aimed to examine factors that influence the percentage BV. METHODS: We devised a formula based on coefficients ("a," "τ," and "b") to predict changes in percentage BV. "a" denotes a significant decrease in percentage BV in the early stages of HD. "τ" represents the transition from early to late phase of HD. "b" denotes the slope of the decrease in percentage BV in the late phase of HD. We measured the percentage BV in 18 patients with end-stage renal disease. The coefficients were estimated by fitting experimental data from patients using a least squares optimization algorithm. A correlation analysis of these parameters and patient predialysis data was performed. RESULTS: Ultrafiltration rate (UFR) was found to be negatively correlated with "b" (r = -0.851, p < 0.01). However, UFR was not significantly related to "a." Predialysis serum total protein level was negatively correlated with "a" (r = -0.531, p = 0.042). Predialysis serum albumin and predialysis sodium were not significantly correlated with "a" and "τ." Plasma osmolarity did not have a significant relationship with "a" and "τ." DISCUSSION/CONCLUSION: UFR influenced the decrease in percentage BV in the late phase but did not influence the decrease of percentage BV in the early phase. "a" was associated with predialysis serum total protein level but not with plasma osmolality or predialysis sodium. This implies that colloid oncotic pressure is important for plasma refilling immediately after dialysis begins. During the change of percentage BV, the decrease in the early phase of dialysis was not related to UFR, but related to other parameters, especially predialysis total protein level. A decrease in the late phase of dialysis is related to UFR.

Factors influencing C-reactive protein status on admission in neonates after birth.

OBJECTIVE: To explore the factors influencing C-reactive protein (CRP) status in neonates on admission after birth. METHODS: 820 newborns born and hospitalized at Xiangya Hospital of Central South University from Jan. 2020 to Dec. 2020 were retrospectively analyzed. Maternal medical history and medication use during pregnancy, neonatal demographic information and status at birth were collected through the electronic medical record system. Statistical software was used to analyze the possible relationship between perinatal factors and CRP on admission after birth. RESULTS: A total of 820 neonates were analyzed, including 463 males and 357 females with a mean gestational age (GA) of 36.07 ± 3.30 weeks. (1) Multifactor Logistic regression analysis: larger GA (OR: 1.13, 95%CI: 1.00-1.28, P = 0.042), premature rupture of membranes (PROM) ≥ 18 h (OR: 2.39, 95%CI: 1.35-4.23, P = 0.003) and maternal autoimmune diseases (OR: 5.30, 95%CI: 2.15-13.07, P < 0.001) were independent risk factors for CRP ≥ 8 mg/L. Cesarean delivery (OR 0.40, 95%CI: 0.26-0.60, P < 0.001) was independent protective factor for CRP ≥ 8 mg/L. (2) Threshold effect analysis: A non-linear relationship was found between GA and CRP. When GA is less than 33.9 weeks, the risk of CRP ≥ 8 mg/L was reduced by 28% with one week increased (P < 0.001), and when GA is more than 33.9 weeks, the risk of CRP ≥ 8 mg/L was increased by 61% with one week increased (P < 0.001). CONCLUSIONS: GA, PROM, maternal autoimmune diseases and cesarean delivery were all independent influences neonatal CRP ≥ 8 mg/L on admission, and there was a nonlinear relationship between GA and neonatal CRP ≥ 8 mg/L on admission.

Effect of glass compression plate on EBT-XD film dosimetry for pretreatment quality assurance of stereotactic body radiotherapy.

Background: EBT-XD film specially designed for high dose verifications such as stereotactic treatments. The dose response of the film can be affected by several factors, the curly nature of the film being one of them. In this study this curly nature of the film was investigated for stereotactic body radiotherapy (SBRT) plan verifications. Materials and methods: For this study, 18 SBRT (11 prostate, 3 spines, and 4 lungs) cases were enrolled. For all the cases, VMAT plans were created in the Monaco treatment planning system and plan was delivered in Elekta Versa HD linear accelerator and delivered fluence was captured by EBT-XD films. All films were scanned with and without a compression plate. All the films were analyzed using the single-channel film method using the red channel. Results: A significant difference in the gamma passing rates (GPR) for the films scanned with and without the compression plate was observed. The maximum percentage differences in GPR between using and not using a compression plate were 12.7% for 1% 1 mm, 8.1% for 2% 2 mm, 7.5% for 3% 2 mm, and 5% for 3% 3mm criteria. Similarly, the mean %difference in GPR was 5.8% for 1% 1 mm, 2.4% for 2% 2 mm, 1.6% for 3% 2 mm and 0.96% for 3% 3 mm criteria. Conclusion: The results suggest that placing a compression plate over the film during scanning provided a great advantage in achieving a more accurate gamma passing rate irrespective of gamma criteria.

DeepFittingNet: A deep neural network-based approach for simplifying cardiac T1 and T2 estimation with improved robustness.

PURPOSE: To develop and evaluate a deep neural network (DeepFittingNet) for T1 /T2 estimation of the most commonly used cardiovascular MR mapping sequences to simplify data processing and improve robustness. THEORY AND METHODS: DeepFittingNet is a 1D neural network composed of a recurrent neural network (RNN) and a fully connected (FCNN) neural network, in which RNN adapts to the different number of input signals from various sequences and FCNN subsequently predicts A, B, and Tx of a three-parameter model. DeepFittingNet was trained using Bloch-equation simulations of MOLLI and saturation-recovery single-shot acquisition (SASHA) T1 mapping sequences, and T2 -prepared balanced SSFP (T2 -prep bSSFP) T2 mapping sequence, with reference values from the curve-fitting method. Several imaging confounders were simulated to improve robustness. The trained DeepFittingNet was tested using phantom and in-vivo signals, and compared to the curve-fitting algorithm. RESULTS: In testing, DeepFittingNet performed T1 /T2 estimation of four sequences with improved robustness in inversion-recovery T1 estimation. The mean bias in phantom T1 and T2 between the curve-fitting and DeepFittingNet was smaller than 30 and 1 ms, respectively. Excellent agreements between both methods was found in the left ventricle and septum T1 /T2 with a mean bias <6 ms. There was no significant difference in the SD of both the left ventricle and septum T1 /T2 between the two methods. CONCLUSION: DeepFittingNet trained with simulations of MOLLI, SASHA, and T2 -prep bSSFP performed T1 /T2 estimation tasks for all these most used sequences. Compared with the curve-fitting algorithm, DeepFittingNet improved the robustness for inversion-recovery T1 estimation and had comparable performance in terms of accuracy and precision.

Nonlinear connection between remnant cholesterol and stroke risk: evidence from the China health and retirement longitudinal study.

OBJECTIVE: The evidence on the relationship between remnant cholesterol (RC) and stroke remains controversial. Therefore, this study aimed to explore the relationship between RC and stroke risk in a Chinese population of middle-aged and elderly individuals. METHODS: The present study included 10067 Chinese subjects of middle-aged and elderly individuals. The connection between RC and incident stroke was investigated using the multivariate Cox proportional hazards regression model, several sensitivity analyses, generalized additive models, and smoothed curve fitting. RESULTS: A total of 1180 participants with stroke were recorded during the follow-up period. The multivariate Cox proportional hazards regression model identified a positive connection between RC and stroke risk (hazard ratio (HR) = 1.087, 95% confidence interval (CI): 1.001-1.180). In addition, the current study discovered a nonlinear connection between RC and incident stroke, and the point of inflection for RC was 1.78 mmol/L. The risk of stroke increased by 25.1% with each unit increase in RC level when RC was < 1.78 mmol/L (HR:1.251, 95%CI: 1.089-1.437, P = 0.0015). The results were not affected by sensitivity tests. CONCLUSION: The current study showed a positive and nonlinear connection between RC and stroke risk in a middle-aged and elderly Chinese population. These findings provided new information to help researchers better understand the relationship between RC levels and incident stroke.

Accurate estimation of peak vertical ground reaction force using the duty factor in level treadmill running.

This study aimed to (1) construct a statistical model (SMM) based on the duty factor (DF) to estimate the peak vertical ground reaction force ( F v , max ) and (2) to compare the estimated F v , max to force plate gold standard (GSM). One hundred and fifteen runners ran at 9, 11, and 13 km/h. Force (1000 Hz) and kinematic (200 Hz) data were acquired with an instrumented treadmill and an optoelectronic system, respectively, to assess force-plate and kinematic based DFs. SMM linearly relates F v , max to the inverse of DF because DF was analytically associated with the inverse of the average vertical force during ground contact time and the latter was very highly correlated to F v , max . No systematic bias and a 4% root mean square error (RMSE) were reported between GSM and SMM using force-plate based DF values when considering all running speeds together. Using kinematic based DF values, SMM reported a systematic but small bias (0.05BW) and a 5% RMSE when considering all running speeds together. These findings support the use of SMM to estimate F v , max during level treadmill runs at endurance speeds if underlying DF values are accurately measured.

Epidemiological trends and seasonal dynamics of tuberculosis in Southeastern Turkey.

Background: Tuberculosis (TB) is an important public health issue. Determining TB trend and seasonal variability provides useful information for designing treatment strategies and control programs. Aim: The present study attempts to investigate the epidemiological trend and the seasonal variations. Materials and Methods: TB data containing 2450 cases were collected over a period of seven years in the province of Diyarbakir in southeast Turkey. Trend function and seasonal variability were investigated by statistical curve fitting, surface fitting, and autoregressive time series analysis. Results: The study revealed a gradually decreasing trend in the number of TB cases over a period of seven years. Total TB incidence had seasonal variations (P = 0.04); there was a greater number of TB cases between April and July, with a peak in June. There were significant monthly seasonal variations with June peaks among females (P < 0.001), in patients in the age groups of 0-15 (P < 0.001) and 36-45 years (P < 0.001), in new cases (P < 0.001) and in the patients with pulmonary TB (P = 0.01). The extra-pulmonary TB cases peak in May (P = 0.01). Pulmonary TB and TB patients in the 36-45 age group had summer peak, while the other groups peaked at spring. Conclusions: Spring and summer peaks detected in total TB cases and in many subgroups indicate that multicenter and comprehensive clinical studies are needed to explain these variations.

Limitations to photosynthesis in bryophytes: certainties and uncertainties regarding methodology.

Bryophytes are the group of land plants with the lowest photosynthetic rates, which was considered to be a consequence of their higher anatomical CO2 diffusional limitation compared with tracheophytes. However, the most recent studies assessing limitations due to biochemistry and mesophyll conductance in bryophytes reveal discrepancies based on the methodology used. In this study, we compared data calculated from two different methodologies for estimating mesophyll conductance: variable J and the curve-fitting method. Although correlated, mesophyll conductance estimated by the curve-fitting method was on average 4-fold higher than the conductance obtained by the variable J method; a large enough difference to account for the scale of differences previously shown between the biochemical and diffusional limitations to photosynthesis. Biochemical limitations were predominant when the curve-fitting method was used. We also demonstrated that variations in bryophyte relative water content during measurements can also introduce errors in the estimation of mesophyll conductance, especially for samples which are overly desiccated. Furthermore, total chlorophyll concentration and soluble proteins were significantly lower in bryophytes than in tracheophytes, and the percentage of proteins quantified as Rubisco was also significantly lower in bryophytes (<6.3% in all studied species) than in angiosperms (>16% in all non-stressed cases). Photosynthetic rates normalized by Rubisco were not significantly different between bryophytes and angiosperms. Our data suggest that the biochemical limitation to photosynthesis in bryophytes is more relevant than so far assumed.

Association between triglyceride-to-high density lipoprotein cholesterol ratio and three-month outcome in patients with acute ischemic stroke: a second analysis based on a prospective cohort study.

OBJECTIVE: Evidence regarding the relationship between serum triglyceride-to-high density lipoprotein cholesterol (TG/HDL-c) ratio and outcomes in acute ischemic stroke (AIS) patients is still mixed. Therefore, the present study was undertaken to explore the link between the TG/HDL-c ratio and unfavorable outcomes in patients with AIS. METHODS: This was a second analysis based on a cohort study. The study population was 1764 patients with AIS collected from January 2010 to December 2016 at a hospital in South Korea. We used a binary logistic regression model to assess the linear association between the TG/HDL-c ratio and unfavorable outcomes for AIS patients. A generalized additive model (GAM) and smooth curve fitting (penalized spline method) was conducted to explore the nonlinear relationship between TG/HDL-c ratio and unfavorable outcomes for AIS patients. Additionally, we compute the inflection point using a recursive algorithm and then build a two-piece binary logistic regression model on both sides of the inflection point. A log-likelihood ratio test was used to determine the most appropriate model describing the association of TG/HDL-c ratio and unfavorable outcomes in patients with AIS. RESULTS: The incidence rate of unfavorable outcomes was 28.2%, and the median TG/HDL-c ratio was 2.130. After adjusting covariates, the results of the binary logistic regression model suggested that the relationship between the TG/HDL-c ratio and the risk of unfavorable outcomes for AIS patients was not statistically significant. However, there was a nonlinear relationship between them, and the inflection point of the TG/HDL-c ratio was 3.515. On the left side of the inflection point, each 1-unit increase in the TG/HDL-c ratio was associated with a 22.6% lower risk of unfavorable outcomes (OR = 0.774, 95%CI:0.656 to 0.914, p = 0.002). On the right side of the inflection point, the effect size (OR) was 1.195 (95%CI:1.004 to1.423, p = 0.003). CONCLUSION: There is a nonlinear relationship and threshold effect between the TG/HDL-c ratio and 3-month unfavorable outcomes in AIS patients. When the TG/HDL-c ratio is lower than 3.515, the TG/HDL-c ratio is significantly negatively related to the risk of unfavorable outcomes. When the TG/HDL-c ratio is greater than 3.515, the TG/HDL-c ratio was positively associated with the risk of unfavorable outcomes in AIS patients. This provides a reference for optimizing lipidemia intervention and promoting clinical communication in patients with AIS.

Profiling of elite male junior 50 m freestyle sprinters: Understanding the speed-time relationship.

The aim of this study was to (1) analyze and compare the race performance and stability between the fastest and slowest male swimmers during the 50 m freestyle event, and (2) to understand the speed-time relationship in this race. The performances (start, clean swim, and finish) of 86 swimmers (divided into two tiers: best and poorest performances) who competed in the 50 m freestyle event in the 2019 long course LEN European Junior Championships were analyzed. The swimming speed presented a significant difference between the groups (tier #1 vs tier #2) in all sections of the race, in which the start (S0-15 m: p < 0.001, d = 1.64) and finish sections (S45-50: p < 0.001, d = 1.63) showed the greatest differences. Significant variances over the race sections were noted for both groups in all variables, in which the swimming speed was the variable with the highest variance (tier #1: p < 0.001, η2  = 0.72; tier #2: p < 0.001, η2  = 0.82). Both groups exhibited a similar normative stability, with the fastest swimmers tending to be the best in all sections. The fit analysis produced a cubic speed-time relationship. Notwithstanding, junior swimmers who raced the 50 m freestyle can be considered to have an all-out pacing. This information is of paramount importance for coaches and swimmers to understand the intra-lap race performance in this short event.

Constant Potential Coulometric Measurements with Ca2+-Selective Electrode: Analysis Using Calibration Plot vs. Analysis Using the Charge Curve Fitting.

The possibility of analysis using charge curve fitting in constant potential coulometric mode instead of using a calibration plot is explored, for the first time. The results are compared with the analysis based on the use of a calibration plot. A Ca2+ ion-selective electrode, with and without an electronic capacitor in series, is used as a model system in pure solutions of CaCl2. Both techniques delivered good results (error within 2%) when the final and the initial concentration values differed by not more than three times. Larger differences result in 10-25% error. The presence of an electronic capacitor in the measurement circuit and in series with the electrode, allows for significantly faster response.

Design and Analysis of Small Size Eddy Current Displacement Sensor.

A systematic method is employed for the design and analysis of a small size eddy current (EC) displacement sensor. Simulations are first performed to determine the optimal winding structure and dimensions of the sensor. A linear-fitting approach is then developed for converting the AC displacement signal of the sensor to a DC signal. Finally, a compensation method is proposed for mitigating the temperature drift of the EC sensor under different working temperatures. The experimental results show that the proposed sensor has a sensitivity of approximately 3 µm, a working temperature range of 25-55 °C, and a linearity of ±1.025%.

A Novel High-Speed Resonant Frequency Tracking Method Using Transient Characteristics in a Piezoelectric Transducer.

When driving the piezoelectric transducer (PT: piezo transducer), which is a key device, it is important for the ultrasonic system (using ultrasonic waves of 20 kHz or higher) to operate at a resonant frequency that can maximize the conversion of mechanical energy (vibration) from electrical energy. The resonant frequency of the PT changes during the actual operation according to the load fluctuations and environmental conditions. Therefore, to maintain a stable output in an ultrasonic system, it is essential to track the resonant frequency in a short time. In particular, fast resonant frequency tracking (RFT: resonant frequency tracking) is an important factor in the medical ultrasonic system, i.e., the system applied in this thesis. The reason is that in the case of a medical ultrasonic system, heat-induced skin necrosis, etc., may cause the procedure to be completed within a short period of time. Therefore, tracking the RFT time for maximum power transfer is an important factor; in this thesis, we propose a new high-speed RFT method. The proposed method finds the whole system resonance frequency by using the transient phenomenon (underdamped response characteristic) that appears in an impedance system, such as an ultrasonic generator, and uses this to derive the mechanical resonance frequency of the PT. To increase the accuracy of the proposed method, parameter fluctuations of the pressure of the PT, the equivalent circuit impedance analysis of the PT, and a MATLAB simulation were performed. Through this, the correlation between the resonance frequency of the ultrasonic system, including the LC filter with nonlinear characteristics and the mechanical resonance frequency of the PT, was analyzed. Based on the analyzed results, a method for tracking the mechanical resonance frequency that can transfer the maximum output to the PT is proposed in this thesis. Experiments show that using the proposed high-speed RFT method, the ultrasonic system can track the mechanical resonance frequency of the PT with high accuracy in a short time.

ScatterHough: Automatic Lane Detection from Noisy LiDAR Data.

Lane detection plays an essential role in autonomous driving. Using LiDAR data instead of RGB images makes lane detection a simple straight line, and curve fitting problem works for realtime applications even under poor weather or lighting conditions. Handling scatter distributed noisy data is a crucial step to reduce lane detection error from LiDAR data. Classic Hough Transform (HT) only allows points in a straight line to vote on the corresponding parameters, which is not suitable for data in scatter form. In this paper, a Scatter Hough algorithm is proposed for better lane detection on scatter data. Two additional operations, ρ neighbor voting and ρ neighbor vote-reduction, are introduced to HT to make points in the same curve vote and consider their neighbors' voting result as well. The evaluation of the proposed method shows that this method can adaptively fit both straight lines and curves with high accuracy, compared with benchmark and state-of-the-art methods.

Equivalent Circuit Model Extraction for a SAW Resonator: Below and above Room Temperature.

In this work, a SAW resonator is characterized in terms of admittance (Y-) parameters in the temperature range spanning from 0 °C to 100 °C, with the aim of highlighting how its physical properties are affected by the temperature change. A lumped-element equivalent-circuit model is used to represent the device under test at the considered temperature conditions and a parameters extraction process based on a Lorentzian fitting is developed for the determination of the equivalent-circuit elements in the investigated temperature range. A very good agreement is observed between the performed measurements and the model simulations. The characterization process and the subsequent equivalent-circuit parameters extraction at different temperature values are described and discussed.

Micro-FTIR combined with curve fitting method to study cellulose crystallinity of developing cotton fibers.

This study aimed to use micro-FTIR with transmission mode to investigate cellulose crystallinity of developing cotton fibers. Compared with ATR-FTIR method, we found that micro-FTIR can obtain more information of cellulose inside of the developing cotton fibers, especially in high wavenumber of 2800-3000 cm-1 region. Combined with curve fitting method, a new IR crystallinity index (CI) method named wax crystallinity index (WCI) was introduced to evaluate the cellulose crystallinity in the development of cotton fibers based on the peak and area ratios of 2900 cm-1/2850 cm-1 and 2900 cm-1/2920 cm-1. The obtained WCI values demonstrated an excellent coefficient of determination with X-ray diffraction (XRD) CI method with the value up to 0.99. This study suggested that micro-FTIR was an effective technique to qualitatively analyze the crystallinity in developing cotton fibers combined with curve fitting method.

Critical speed estimated by statistically appropriate fitting procedures.

PURPOSE: Intensity domains are recommended when prescribing exercise. The distinction between heavy and severe domains is made by the critical speed (CS), therefore requiring a mathematically accurate estimation of CS. The different model variants (distance versus time, running speed versus time, time versus running speed, and distance versus running speed) are mathematically equivalent. Nevertheless, error minimization along the correct axis is important to estimate CS and the distance that can be run above CS (d'). We hypothesized that comparing statistically appropriate fitting procedures, which minimize the error along the axis corresponding to the properly identified dependent variable, should provide similar estimations of CS and d' but that different estimations should be obtained when comparing statistically appropriate and inappropriate fitting procedure. METHODS: Sixteen male runners performed a maximal incremental aerobic test and four exhaustive runs at 90, 100, 110, and 120% of their peak speed on a treadmill. Several fitting procedures (a combination of a two-parameter model variant and regression analysis: weighted least square) were used to estimate CS and d'. RESULTS: Systematic biases (P < 0.001) were observed between each pair of fitting procedures for CS and d', even when comparing two statistically appropriate fitting procedures, though negligible, thus corroborating the hypothesis. CONCLUSION: The differences suggest that a statistically appropriate fitting procedure should be chosen beforehand by the researcher. This is also important for coaches that need to prescribe training sessions to their athletes based on exercise intensity, and their choice should be maintained over the running seasons.