Comparison of eight methods of Weibull distribution for determining the best-fit distribution parameters with wind data measured from the met-mast.

In order to assess the wind characteristics of a specified region, a pre-analysis of the region can be made with different numerical methods. For instance, the two-parameter Weibull distribution is widely used in wind energy studies and the wind energy sector to obtain information about the wind characteristics of the specified region. The main goal of this study is to perform a detailed analysis of the data obtained from the wind measurement sensors on a meteorological mast with a height of 80 m to determine the wind characteristics and wind energy potential of a region in Osmaniye, Turkey. The suitability of the two-parameter Weibull distribution, which is the most popular probability distribution model, was investigated to evaluate the distribution of these wind data. In the precise determination of the Weibull distribution parameters (k and c), the suitability of eight different numerical methods, namely, graphical (GM), empirical of Justus (EMJ), empirical of Lysen (EML), power density (PDM), moment (MoM), maximum likelihood (MLM), modified maximum likelihood (MMLM), and alternative maximum likelihood (AMLM) methods, was examined. Root-mean-square error (RMSE), chi-square (X2), and analysis of variance (R2) were used to compare and verify the performance of these models. The best and worst performances in these eight methods were MMLM and GM, compared with the actual measured data. Also, wind power density was calculated considering these methods and prevailing wind directions.

A comparison of short term radiological alignment outcomes of the patient specific and standard instrumentation for primary total knee arthroplasty: A systematic review and meta-analysis.

OBJECTIVE: The aim of this study was to review the radiological alignment outcomes of patient Specific (PS) cutting blocks and Standard Instrumentation in Primary Total Knee Arthroplasty. METHODS: We hypothesized that the use of PS techniques would significantly improve sagittal, coronal and rotational alignment of the prosthesis on short term. We performed a systematic review and a meta-analysis including all the randomised controlled trials (RCT) using PS and standard (ST) total knee arthroplasty to date. RESULTS: A total of 538 PS TKA and 549 ST TKA were included in the study. Statistical analysis of the outliers for femoral component sagittal, coronal and rotational positioning, tibial component sagittal and coronal positioning and the overall mechanical axis were assessed. We found that there was no significant benefit from using PS instrumentation in primary knee arthroplasty to aid in the positioning of either the tibial or femoral components. Furthermore sagittal plane tibial component positioning was worse in the PS than the traditional ST group. CONCLUSION: Our results suggest that at present PS instrumentation is not superior to ST instrumentation in primary total knee arthroplasty. LEVEL OF EVIDENCE: Level 1, Systematic review of therapeutic studies.