Early Fault Detection based on Ball Bearing Vibration Analysis using Multinomial Logistic Regression

Author(s):  
Thanadat Kerdsiri ◽  
Rutchanee Gullayanon
Author(s):  
F. Bakhtiary-Nejad ◽  
A. H. Nayeb ◽  
S. E. Yeganeh

In this paper, existence of localized defects in a ball bearing has been diagnosed using vibration analysis. First, different kinds of faults which occur in ball bearings have been investigated. Then an analytical model has been proposed for determining the damaged ball bearing vibrations due to a localized defect. Also various methods of fault detection have been evaluated. Next, in order to examine the ball bearings, a testing set-up has been designed and constructed. Then by preparing a computer program, which calculates defect frequencies, some ball bearings have been tested. The test results were originally derived in time-domain. Then by using vibration analysis of healthy and damaged ball bearings in frequency-domain, a fault detection method for ball bearings has been proposed.


2020 ◽  
Author(s):  
Khayriyyah Mohd Hanafiah ◽  
Chang Da Wan

The COVID-19 pandemic is the first to occur in an age of hyperconnectivity. This paper presents results from an online anonymous survey conducted in Malay, English, and Chinese, during the first week of the Movement Control Order in Malaysia (n=1075), which aimed to examine public knowledge, perception and communication behavior in the Malaysian society in the face of a sudden outbreak and social distancing measures. Although the level of public knowledge, risk perception and positive communication behavior surrounding COVID-19 was high, a majority of respondents reported receiving a lot of questionable information. Multinomial logistic regression further identified that responses to different items varied significantly across respondent survey language, gender, age, education level and employment status.


2021 ◽  
Author(s):  
Pei Wang ◽  
Erin L. Abner ◽  
David W. Fardo ◽  
Frederick A. Schmitt ◽  
Gregory A. Jicha ◽  
...  

Author(s):  
Nobutoshi Nawa ◽  
Yui Yamaoka ◽  
Yuna Koyama ◽  
Hisaaki Nishimura ◽  
Shiro Sonoda ◽  
...  

Face mask use is a critical behavior to prevent the spread of SARS-CoV-2. We aimed to evaluate the association between social integration and face mask use during the COVID-19 pandemic in a random sample of households in Utsunomiya City, Greater Tokyo, Japan. Data included 645 adults in the Utsunomiya COVID-19 seROprevalence Neighborhood Association (U-CORONA) study, which was conducted after the first wave of the pandemic, between 14 June 2020 and 5 July 2020, in Utsunomiya City. Social integration before the pandemic was assessed by counting the number of social roles, based on the Cohen’s social network index. Face mask use before and during the pandemic was assessed by questionnaire, and participants were categorized into consistent mask users, new users, and current non-users. Multinomial logistic regression analysis was used to examine the association between lower social integration score and face mask use. To account for possible differential non-response bias, non-response weights were used. Of the 645 participants, 172 (26.7%) were consistent mask users and 460 (71.3%) were new users, while 13 (2.0%) were current non-users. Lower social integration level was positively associated with non-users (RRR: 1.76, 95% CI: 1.10, 2.82). Social integration may be important to promote face mask use.


Sign in / Sign up

Export Citation Format

Share Document