Parameter searching is one of the most important aspects in getting favorable results in optimization problems. It is even more important if the optimization problems are limited by time constraints. In a limited time constraint problems, it is crucial for any algorithms to get the best results or near-optimum results. In a previous study, Differential Evolution (DE) has been found as one of the best performing algorithms under time constraints. As this has help in answering which algorithm that yields results that are near-optimum under a limited time constraint. Hence to further enhance the performance of DE under time constraint evaluation, a throughout parameter searching for population size, mutation constant and f constant have been carried out. CEC 2015 Global Optimization Competition's 15 scalable test problems are used as test suite for this study. In the previous study the same test suits has been used and the results from DE will be use as the benchmark for this study since it shows the best results among the previous tested algorithms. Eight different populations size are used and they are 10, 30, 50, 100, 150, 200, 300, and 500. Each of these populations size will run with mutation constant of 0.1 until 0.9 and from 0.1 until 0.9. It was found that population size 100, Cr = 0.9, F=0.5 outperform the benchmark results. It is also observed from the results that good higher Cr around 0.8 and 0.9 with low F around 0.3 to 0.4 yields good results for DE under time constraints evaluation

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ObjectiveThe aim of this study was to establish reference values for rate of torque development (RTD) and muscle torque steadiness (MTS) of knee extensors across the lifespan, and evaluate if these measures are independently associated with Osteoarthritis Research Society International (OARSI)–recommended performance-based measures (6-minute walk test, 30-second chair stand test, stair climb test) and other clinical variables.MethodsIn this cross-sectional observational study, knee extensor strength of 764 participants (12–89 years) from the 1000 Norms Project was assessed via fixed dynamometry. Age- and sex-stratified normative RTD (Nms−1 kg−1) and MTS (Nm kg−1) values were presented as means and 95% confidence intervals. Correlations and multiple regression analyses were calculated to identify factors (age, sex, height, weight, OARSI-recommended performance-based measures, Knee Injury and Osteoarthritis Outcome Score, vertical jump, long jump, grip strength, basic gait-related knee biomechanics) independently associated with RTD or MTS.ResultsAge- and sex-stratified normative RTD and MTS reference values were generated. Male subjects exhibited higher RTD but poorer MTS (less steady) than female subjects across all age groups. Better performance in OARSI-recommended performance-based measures, vertical jump, long jump, and grip strength were associated with greater RTD but poorer MTS. Thirty-second chair stand test, stair climb test, vertical jump, long jump, and grip strength were independent determinants of RTD and MTS.ConclusionsThe RTD and MTS demonstrated associations with clinical variables relevant to knee osteoarthritis. The normative reference values generated may help identify the presence and extent of impairments in RTD and MTS associated with knee osteoarthritis and assist in developing responsive outcome measures for therapeutic trials.