A novel stochastic resonance based deep residual network for fault diagnosis of rolling bearing system.

Rolling bearings constitute one of the most vital components in mechanical equipment, monitoring and diagnosing the condition of rolling bearings is essential to ensure safe operation. In actual production, the collected fault signals typically contain noise and cannot be accurately identified. In the paper, stochastic resonance (SR) is introduced into a spiking neural network (SNN) as a feature enhancement method for fault signals with varying noise intensities, combining deep learning with SR to enhance classification accuracy. The output signal-to-noise ratio(SNR) can be enhanced with the SR effect when the noise-affected fault signal input into neurons. Validation of the method is carried out through experiments on the CWRU dataset, achieving classification accuracy of 99.9%. In high-noise environments, with SNR equal to -8 dB, SRDNs achieve over 92% accuracy, exhibiting better robustness and adaptability.

Numerical Investigation of Triaxial Shear Behaviors of Cemented Sands with Different Sampling Conditions Using Discrete Element Method.

In cemented sand, the influences of the sampling factors (i.e., the curing time, cement-sand ratio, and initial void ratio) on the triaxial shear behavior were investigated using discrete element method. Cemented sand samples with different initial conditions were prepared and subjected to the consolidated drained triaxial shearing test. In the simulations, the peak strength, residual strength, and pre-peak stiffness of cemented sand were enhanced by increasing the curing time and cement-sand ratio, and the enhancements could be explained by the increases in bond strength and bond number. Resulting from the increases of these two sampling factors, bond breakage emerged at a greater axial strain but lower intensity. However, some uncommon phenomena were generated; that is, the contractive but strain-softening response occurred in the sample with a curing time of 3 days, and the shear band and the strain-hardening behavior coexisted in the sample with a cement-sand ratio of 1%. The peak strength and pre-peak stiffness were also enhanced by decreasing the initial void ratio, more distinctly than by increasing the curing time and cement-sand ratio. However, the residual strength, bond breakage, and failure pattern with the persistence of shear band were insensitive to this change.

The clinical analysis of bilateral successive sudden sensorineural hearing loss.

The objective of this study is to investigate the clinical characteristics of successive bilateral sudden sensorineural hearing loss (SSNHL) with an interval of more than 1 year to aid the evaluation and management of successive bilateral SSNHL (BSSNHL). 14 successive BSSNHL patients and 118 unilateral SSNHL patients with severe and profound hearing loss were reviewed retrospectively. Information about successive BSSNHL was collected included demographics, the intervals between the attacks of bilateral ears, the past medical history, inducing factors, accompanying symptoms, pure-tone tests, blood tests, b-ultrasound examinations of vertebral artery and carotid artery, and medical interventions. And the comparison of improvement rate was made between successive BSSNHL and unilateral SSNHL. SPSS 15.0 was used to analyze the data. In successive BSSNHL, there were six males and eight females; the average aged was 49.86 ± 15.45 years (20-73 years). The interval of the two attacks was 11.43 ± 12.07 years (1-50 years) on average. The onset of treatment was 18.86 ± 12.71 days. Tinnitus was seen in 100 % of the patients, followed by vertigo in 42.85 %, and ear fullness in 21.43 %. 3 of 14 patients described obvious inducing factor: tiredness. Five patients (35.71 %) had hypertension histories, three (21.43 %) had diabetes histories, two (14.29 %) had surgery histories, one (7.14 %) was with depression history, one (7.14 %) was with coronary heart disease history. 30 % (3/10) patients were with atherosclerotic plaque in carotid artery. 4 (28.57 %) patients were with high blood sugar. 8 patients (57.14 %) were with high blood lipids. Thyroid function tests were positive in 27.27 % (3/11) patients. No abnormality was found in antinuclear antibodies titer. The percentage of profound and severe hearing loss were 71.43 and 78.57 % in the recently affected ear and contralateral ear separately. The PTAs of the recently affected ear were 77.14 ± 27.12 dB before treatment and 68.84 ± 22.32 dB after treatment, the improvement rate was 28.57 %. No improvement was found in the contralateral ears. In unilateral SSNHL, the average age was 42.47 ± 14.18 years. The onset of treatment was 18.08 ± 15.84 days. The improvement rate was 57.63 %, which was much higher than that of successive BSSNHL. There was no difference in age and time of onset of treatment between successive BSSNHL and unilateral SSNHL (p > 0.05). Successive BSSNHL is rare, the hearing impairment is severe, and the outcome of treatment is poorer. It may have a completely different profile compared with the simultaneous BSSNHL and unilateral SSNHL.

[Exercise pharynx and genioglossus to treat obstructive sleep apnea and hypopnea syndrome].

OBJECTIVE: To discuss the method and effect of exercising larynx and genioglossus to treat obstructive sleep apnea hypopnea syndrome (OSAHS). METHOD: Fifty-four patients who were diagnosed as OSAHS and exercised larynx and genioglossus were defined as treatment group. We took Epworth sleep scale, check patient's PSG, and took computer tomography (320CT) before treatment, 6 months and 12 months later. We made a record of AHI, LSaO2, BMI, the shortest sagittal diameter and transverse diameter. Compared with 30 patients who had taken UPPP surgery (control group 1) and the 21 patients without any treatment (control group 2) at the same time. SPSS 10.0 was used to analyze the data. RESULT: According to Chinese OSAHS construction in 2009, 6 months and 12 months later, the effective rates of treatment group were 31.48% and 44.44%, among which the effective rates in mild and moderate patients of treatment group were 44.74% and 63.16%. Before treatment the mark of Epworth sleep scale was 7.67, 6 month and 12 month later the marks were 3.54 and 3.25. AHI were up to 15.45 after 6 months and 13. 60 after 12 months from 22. 84 at the beginning. LSaO2 were up to 81.18% after 6 months and 81.93% after 12 months from 74.05% at the beginning. The effective rate of control group 1 was 66.67%, and was much higher than the treatment group 6 months later (P < 0.05). But there was no statistics difference of effective rate between treatment group and control group 1 (36.67%) after 12 months (P > 0.05). The effective rates of treatment group were much higher than control group 2 (P < 0.01). After 12 months, the sagittal wall compliance of retropalatal area was lower (P < 0.01). There was no significant change of BMI in every group. CONCLUSION: Exercising larynx and genioglossus is one kind of non-invasive and effective method without payment to treat part of OSAHS patients, especially the patients who is old, without surgical condition, and especially mild and moderate OSAHS patient that do not want to take surgery and CPAP treatment. Besides, exercising larynx and genioglossus can be considered as remedial treatment of OSAHS to surgery and other therapy.

[Evaluation of upper airway resilience under Müller respiration by non-endoscopic method].

OBJECTIVE: To evaluate diagnostic significance of the noninvasive and objective 320-slice CT scan in the high pharynx resilience in the patients with obstructive sleep apnea/hypopnea syndrome. METHOD: Fifty patients with OSAHS and 10 patients with pharyngeal paraesthesia were included in the study. 320 slice CT scan was used to measure the sagittal diameters, transverse diameters and sectional area of the retropalatal region, retroglossal region. Calculating the pharynx wall resilience. Analyzing the correlativity of pharynx wall resilience, BMI and AHI. Fiber endoscope was used to assess the subsidence percentage of the pharynx wall. RESULT: Between OSAHS patients and pharyngeal paraesthesia patients, there was obviously difference in the retropalatal region and retroglossal region upper airway. The pharynx wall resiliences of retropalatal region were much more than that of retroglossal region. The later pharynx wall resiliences were much more than the fore-to-aft pharynx wall resiliences in the retropalatal region. BMI, AHI and the pharynx wall resilience were positive correlative to each other. But AHI and the pharynx wall resilience was nonlinear correlative. There was a good concordance between the pharynx wall resilience detected by 320CT and subsidence percentage of the pharynx wall detected by fiber endoscope. CONCLUSION: 320 slice CT is a kind of simple, rapid and objective method to localize the high resilience area of upper respiratory tract, which can be benefit to the clinical diagnosis, the etiological study and the treatment of OSAHS. Based on physical examination, we propose that only one time of CT scan to the patients' upper airway at the Muller' stage is enough to localize the stenosis area, which can reduce radiation dosage dramatically.

[Clinical research of 24-hour double-probe pH-metry in the laryngopharyngeal reflux diseases].

OBJECTIVE: To determine the clinical value of 24 h double-probe pH-metry for the diagnosis and treatment of laryngopharyngeal reflux (LPR). METHODS: According to the pH-metry results (whether the reflux events record in the upper esophagus is more than 6.9), patients of refractory pharyngolaryngitis were divided into LPR and control groups (each of 17 cases). All patients treated with anti-acid therapy and conventional pharyngo-laryngitis therapy. Correlation between pH-metry and the reflux symptom index (RSI), the reflux symptom index (RFI) were analyzed. Changes of the RSI and RFI in different group were calculated in post-treatment. RESULTS: In the LPR group, the median reflux events of the upright time were higher than the supine time (Z = -3.62, P < 0.01), but the difference was not discovered in the control group (Z = -0.60, P > 0.05). There was no statistical difference between RSI, RSI and RFS with pH-metry, and with moderate concordance (k were 0.47, 0.53, P < 0.01, respectively). Compared to pre-treatment, the RSI and RFI were decreased both in LPR group and control group, Amplitude decreased in LPR group significantly higher than the control groups, with statistical difference (t were 3.74, 3.01, P < 0.01, respectively). CONCLUSION: The 24 h double-probe pH-metry is significant for the anti-acid therapy of LPR.