Search results for "Earing"
showing 10 items of 867 documents
Autoencoders and Recurrent Neural Networks Based Algorithm for Prognosis of Bearing Life
2018
Bearings are one of the most critical components in electric motors, gearboxes and wind turbines. Therefore, bearing fault detection and prognosis of remaining useful life are important to prevent productivity losses. In this study, a novel method is proposed for prognosis of bearing life using an autoencoder and recurrent neural networks-based prediction algorithm. Promising results have been obtained from the experimental data. A monotonic upward trend of the produced health indicator is obtained for all test cases, being one of critical indicators of a proper prognosis. The remaining useful life estimation is moderately accurate under a limited data.
Autoencoders and Data Fusion Based Hybrid Health Indicator for Detecting Bearing and Stator Winding Faults in Electric Motors
2018
The main objective of a condition monitoring programs is to track the health status of critical components of a machine. In this paper, a hybrid health indicator is proposed to monitor the health status of bearings and stator winding of a motor. The proposed method is based on a feature learning from deep autoencoders and data fusion. The features can be learned by autoencoders using individual current and vibration signals, and then learning features are fused to make final health indicators. The experimental data from a permanent magnet synchronous motor is used to validate the proposed method. Promising results in detecting faults and severities of the stator and bearing faults at differ…
Bearing fault diagnosis for inverter-fed motors via resonant filters
2014
Current-based technique is an economic solution to detect bearing faults in drive-trains. Localized faults produce characteristic vibration frequencies. When an electric motor is supplied by a frequency-converter, the current response includes not only the fundamental and fault related frequencies but also higher harmonics from the inverter. This paper introduces a resonant filter to pick up frequency components caused by the localized faults. The bearing fault frequencies are calculated by bearing geometry and motor speeds. The filter frequencies are selected as a function of motor speeds. The filter is independent of the load condition, so it can work at different motor operating points t…
A stepper motor-driven microelectrode positioner
1987
The mechanical elements and the electronic control system from a stepper motor-driven microelectrode positioner is described. The unit embodies a high-precision small step angle hybrid motor. The compact, rugged and totally concentric design of the mechanic, by a spindle mechanism achieves the necessary precision by translating the stepwise rotations of the motor into steps of linear movement. The system takes advantage of commercially available low friction parts such as ball bearings, ball bushings and axles with hardened surfaces. The related electronic control unit is designed around the most recent integrated circuitry which is both sophisticated and economical. Though the described sy…
Adolescents' experiences of parental employment and parenting: connections to adolescents' well-being.
2004
This paper examines whether the relationship between parental work and adolescents' well-being would be mediated through parenting behaviour. The primary focus was on the experiences of adolescents. Questionnaire-based data from families (both parents and one children, n = 77) and adolescents (n = 126) were collected in Finland in 2000 and 2001, respectively. The adolescents were on average 14 years old. Results showed that the relationships between parents' negative work experiences and adolescents' depression (all perceived by adolescents) were partially mediated by adolescents' experience of lessened autonomy granting in parenting and increased conflicts between parents and adolescents. …
Universal Breadwinner Versus Universal Caregiver Model : Fathers’ Involvement in Caregiving and Well-Being of Mothers of Offspring with Intellectual …
2015
Background The universal breadwinner model means both parents are employed; while the universal caregiver model implies that the father's hours of caregiving are equal or higher to those of the mother. This study aims to examine the hypothesis that the universal caregiver model is more related to the overall well-being of mothers of children with intellectual disabilities than the universal breadwinner model. Methods Face-to-face interview surveys were conducted in 2011 in Taiwan with 876 working-age mothers who had an offspring with intellectual disabilities. The survey included 574 mothers living with their husbands who became our participants. Results Both anova and regression analyses i…
Cause, pathogenesis, clinical manifestations and treatment of meniere's disease and endolymphatic hydrops
2019
Meniere's disease (MD) is characterized by the triad of fluctuating hearing loss, episodic vertigo and tinnitus, and by endolymphatic hydrops found on postmortem examinations. Since the description of endolymphatic hydrops by Hallpike and Cairns all the physiopathology of Meniere's symptoms have been based on assumption that the pathologic lesion was the cause of the symptoms. Paparella came out term and concept towards understanding of a disease was, "pathogenesis," which applies to all otological diseases, in general and in particular within this context of MD, which allows us to better understand this disease. After Schuknecht proposed the theory of membranous rupture causing the mixing …
Meniere's disease: Therapeutic options
2021
Meniere's disease (MD) is characterized by the triad of fluctuating hearing loss, episodic vertigo and tinnitus, and by endolymphatic hydrops found on postmortem examinations. Since the description of endolymphatic hydrops by Hallpike and Cairns, the physiopathology of Meniere's symptoms has been based on assumption that the pathologic lesion was the cause of the symptoms. Schuknecht proposed the theory of membranous rupture causing the mixing up of endolymph and perilymph leading to the occurrence of Meniere's symptoms. Lawrence confirmed this theory with research on experimental animals. In 1995 the AAO-HNS criteria defines "Possible MD (Grade D), Probable MD (Grade C), Definite MD (Grade…
Increasing the Capacity of Existing Bridges by Using Unbonded Prestressing Technology: A Case Study
2014
External posttensioning or unbonded prestressing was found to be a powerful tool for retrofitting and for increasing the life extension of existing structures. Since the 1950s, this technique of reinforcement was applied with success to bridge structures in many countries, and was found to provide an efficient and economic solution for a wide range of bridge types and conditions. Unbonded prestressing is defined as a system in which the post-tensioning tendons or bars are located outside the concrete cross-section and the prestressing forces are transmitted to the girder through the end anchorages, deviators, or saddles. In response to the demand for a faster and more efficient transportati…
Integrating Advanced Visual Information with Ball Projection Technology Constrains Dynamic Interceptive Actions
2014
The role of advanced visual information in ball catching was investigated by integrating video images of action and ball projection technology in four different conditions: Integrated video and ball projection (VBP), Video-Only (VO), Ball Projection-Only (BPO) and Misleading Ball projection (MBP). Hand kinematics and gaze behaviour data were collected from participants who attempted to catch balls one handed in all conditions. During VBP, catching performance was more successful, tracking of the ball occurred earlier and lasted longer, with maximum grip aperture emerging earlier with a slower maximum velocity than in BPO. During VO, movement emerged later than VBP, with larger maximum and m…