maximum likelihood method

In this paper, we develop two acceptance sampling plans where the lifetimes of the product follow Weibull Exponential and Weibull Lomax distributions both belonging to the new truncated Weibull–X family of distributions based on run lengths of the conforming items. The model parameters are estimated by using the maximum likelihood method contrary to the existing plans where authors have been selecting arbitrary values of the parameters. The efficiency of the proposed plan is established by comparing it with the existing plans based on the average number of inspected items. A real example of failure rates of a piece of electronic equipment operating in a specific mode is presented to illustrate the proposed plans for industrial use.

The objective of this study is to develop analytical fragility curves for an ensemble of 3- to 6-story existing residential steel buildings with concentrically braced frames in two directions, designed during 2010 and 2015, and located in Qazvin, Iran. The buildings are modeled three-dimensionally in the OpenSees, considering braces buckling behavior. Maximum interstory drift ratio ( ) and spectral acceleration at fundamental period of the structure with 5% viscous damping ( ) are considered as Damage index ( ) and Intensity measure ( ), respectively. Limit states are specified as discussed in FEMA 356. Ground motion record selection and uncertainties assessment is carried out based on FEMA P695 methodology. Analysis is performed using truncated incremental dynamic analysis ( ). Fragility function is defined as a log-normal cumulative distribution function ( ) and maximum likelihood method is used to estimate fragility parameters. According to the fragility curves obtained, seismic vulnerability of the structures is generally increased as the number of stories rises. Concentration of the inelasticity is also found to be mainly at the first story level. The results also confirm the fact that the record to record variability is the main source of uncertainty in structural probabilistic evaluation.

In this study the potential of wind energy in Osmaniye Region has been analysed statistically in the basis of information that has been measured hourly between the years of 2009-2013. The two parameter Weibull Distribution Function is generally applied to evaluate potential of wind energy at any region. This study introduced the evaluation of Weibull Distribution Function parameters which are obtained by different kinds of numerical methods, namely Graphical Method (GM), Moment Method (MM), Energy Pattern Method (EPM), Energy Trend Method (ETM) and Maximum Likelihood Method (MLM). The Relative Percentage Error (RPE) statistical test is used to compare the efficiency of all used methods. The calculated power density of all used numerical methods is a major key issue for suitability use of wind energy. The evaluation of Weibull parameters and wind power distribution play a crucial role in producing electricity from wind power. The results of the used methods are compared and the obtained pre-research results show that the wind energy potential in Osmaniye Region is statistically suitable for electricity production.