A Robust Data-driven Process Modeling Applied to Time-series Stochastic Power Flow

In this paper, we propose a robust data-driven process model whose hyperparameters are robustly estimated using the Schweppe-type generalized maximum likelihood estimator. The proposed model is trained on recorded time-series data of voltage phasors and power injections to perform a time-series stochastic power flow calculation. Power system data are often corrupted with outliers caused by large errors, fault conditions, power outages, and extreme weather, to name a few. The proposed model downweights vertical outliers and bad leverage points in the measurements of the training dataset. The weights used to bound the influence of the outliers are calculated using projection statistics, which are a robust version of Mahalanobis distances of the time series data points. The proposed method is demonstrated on the IEEE 33-Bus power distribution system and a real-world unbalanced 240-bus power distribution system heavily integrated with renewable energy sources. Our simulation results show that the proposed robust model can handle up to 25% of outliers in the training data set.Comment: Submitted to the IEEE Transactions on Power System

Novel Control Strategy for VSI and CSI Active Filters and Comparing These Two Types of Filters

Recently to eliminate the harmonics and improve the power factor of the power networks, much attention has been attracted to active filters. The advantages of these filters are lower volume and their better compensating characteristics than the passive filters. In conventional sliding mode controllers, the source current waveform is fluctuated in near to zero values. In this paper, using a new sliding technique, lower Total Harmonic Distortion (THD) in source current is obtained and the current waveform is improved. As well as, two novel control strategies for two types of active filters, VSI and CSI is proposed and then these two types of filters are compared to reduce THD value of source current.The proposed controlled strategies are simulated by MATLAB/Simulink. The Simulation results confirm that the proposed strategies reduce the THD of source current more than other strategies, and active filter based on CSI has a better performance than active filter based on VSI with a dead time area (for avoiding short circuit of the source) in high powers

Interaction of Zagros heights effects on precipitation and wind vertical velocity of convective systems in the west of Iran

Considering the significance of Zagros heights in precipitation distribution, the present study using the RegCM4 model and its simulations, the effect of Zagros heights on convective Cumulative precipitation and vertical velocity of different levels of the atmosphere was investigated. The required data was obtained from NCEP/NCAR with a 2.5 resolution from 22 to 38 latitude and from 38 to 58 longitudes on a grille with a horizontal resolution of 10 KMs and 30 SEC time steps for 2000 to 2005.Comprehensive cumulative convective systems were evaluated in two control run an experimental run and, effects of the Zagros heights in warm and cold seasons of the year was examined on these parameters. Results indicated that cores of rainfall during December-January after crossing system have been weakened, while April systems in East Zagros have continued to operate with the same power. Zagros heights in the months of December-January increased rainfall in West Iran and reduced in the Zagros East. In contrast, in April, there is no significant difference between the two runs in the Zagros East between convective precipitations. And maximum precipitation in both runs, is focused in West Iran and Zagros region and its minimum is focused Zagros East and Iran's central plains; But by eliminating the Zagros heights, the convective rainfall this month has increased on the shores of the Caspian Sea. The Zagros heights has to effect on vertical wind velocity profiles of Low levels and the speed and extent of the jet stream cores of high levels of the atmosphere; So that in April resulted movement atmospheric jet stream from level 200 to 400 hp and increases their speed and extent; So, the flows pattern of the mesoscale convective systems and the convective precipitation resulting from them were influenced by the elevation pattern; and kind and how the Zagros heights effects on convective precipitation and vertical profiles of wind speed in the warm and cold months of year is different; in a way that, the wind slowed down at low levels of the atmosphere in December and increased in January and April

The Effect of Educational Intervention Using Attitude- Behavior Pattern of Health Nutrition on Labor Productivity Index

Introduction: The success of each company is related to the performance and productivity of its employees. Recent ergonomic research on this case has confirmed the relation of high stress level, weight, and other risk factors with employees' health care costs and absences. The aim of this study was to introduce the economic and productivity results derived from implementing the interventions of nutrition education using the awareness promotion, attitude correction, and behavior of labors approach according to needs of work places at the selected industry. Methods: The intervention group consisted of 104 male employees who worked at the assembly line of automobile industry and received nutrition education using the active and passive methods in a one-month intervention. To measure the effect of intervention, the health indicators of blood pressure, and body mass index, as well as the awareness questionnaire were used as the pretest and posttest measures. Data analysis was conducted using paired sample T-test using the SPSS22. The economic results achieved from the intervention were expressed as the percentage of production increase or the workers' working hours. Results: Based on the research findings, nutrition education had significantly positive effect on low blood pressure (P-value= 0.000), awareness promotion (P-value= 0.004), employee attitude (P-value= 0.003), and healthy nutrition consumption (P-value= 0.037). It also had positive but not significant effect on body mass index (P-value= 0.448). Conclusion: Ergonomic interventions with awareness promotion and attitude style approach had meaningful effect on health promotion and efficiency of labor