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A Hybrid Rough Set Theory-PSO Technique for Solving of Non-convex Economic Load Dispatch
Amin Safari,Davoud Moghaddam Sheibai 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.12
This paper applies a novel hybrid rough set theory-particle swarm optimizer technique, namely rough particle swarm optimization (RPSO) algorithm, for solving non-convex economic load dispatch (NELD) problem. The RPSO algorithm is based on the notion of rough patterns that uses rough values defined with upper and lower intervals in which represent a set of values. This RPSO method is suggested to deal with the practical constraints such as valve point loading effect, generation limitation, ramp rate limits and prohibited operating zones in the NELD problems. Simulations were performed on four different power systems with 3, 6, 15 and 40 generating units and the results are compared with classical PSO and crazy PSO algorithms. The results of this study reveal that the proposed approach is able to find appreciable NELD solutions than those of previous algorithms.
Kalantari Meybodi, Mahdi,Shokrollahi, Amin,Safari, Hossein,Lee, Moonyong,Bahadori, Alireza Elsevier 2015 Chemical engineering research & design Vol.95 No.-
<P><B>Abstract</B></P> <P>Interfacial tension plays a major role in many disciplines of science and engineering. Complex nature of this property has restricted most of the previous theoretical studies on thermophysical properties to bulk properties measured far from the interface. Considering the drawbacks and deficiencies of preexisting models, there is yet a huge interest in accurate determination of this property using a rather simple and more comprehensive modeling approach. In recent years, inductive machine learning algorithms have widely been applied in solving a variety of engineering problems. This study introduces least-square support vector machines (LS-SVM) approach as a viable and powerful tool for predicting the interfacial tension between pure hydrocarbon and water. Comparing the model to experimental data, an excellent agreement was observed yielding the overall squared correlation coefficient (<I>R</I> <SUP>2</SUP>) of 0.993. Proposed model was also found to outperform when compared to some previously presented multiple regression models. An outlier detection method was also introduced to determine the model applicability domain and diagnose the outliers in the gathered dataset. Results of this study indicate that the model can be applied in systems over temperature ranges of 454.40–890°R and pressure ranges of 0.1–300MPa.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Least square support vector machine (LS-SVM) algorithm is used to estimate Interfacial tension (IFT). </LI> <LI> The model has been developed and tested using several hundreds series of the data. </LI> <LI> Validity of the presented models has been evaluated by utilizing several statistical parameters. </LI> <LI> The predictions of the developed models results are in excellent agreement with data. </LI> </UL> </P>
Reduction in labor pain by intrathecal midazolam as an adjunct to sufentanil
Alireza Salimi,Reza Amin Nejad,Farhad Safari,Seyed Amir Mohajaerani,Rahim Jahanbakhsh Naghade,Kamran Mottaghi 대한마취통증의학회 2014 Korean Journal of Anesthesiology Vol.66 No.3
Background: Anesthesia today has strived to decrease labor pain in a tolerable and controllable fashion. Intrathecal midazolam has been introduced as an adjunct to analgesics. The study was planned to assess the efficacy, safety and duration of analgesia produced by intrathecal midazolam adjunct to sufentanil in decreasing labor pain. Methods: In a randomized clinical trial 80 parturient included in the study. The two groups were matched for age, cervical dilation, gravid, gestational age, and other demographic characteristics. Combination of sufentanil and midazolam administered intrathecally to experimental group and compared to sufentanil group. Time to reach maximum block, and pain score was measured and recorded. Results: Groups were matched for age and weight and other demographic characteristic. No significant adverse effect was seen in both groups including decrease in Apgar score. Duration of analgesia was 92.0 ± 12.7 in sufentanil group and 185.2 ± 15.2 minutes in midazolam and sufentanil group which was significantly different (P = 0.002). Numeric rating scale score was significantly lower in midazolam group compare to sufentanil group at 120 min (P = 0.01), 150 min (P = 0.0014), and 180 min (P = 0.001). Conclusions: Intrathecal midazolam as an adjunct to opioid could significantly enhance analgesia in labor pain with no significant adverse effect. Intrathecal injection of midazolam is an appropriate alternative to parenteral or epidural analgesia in small hospital settings.
Optimum Network Reconfiguration to Improve Power Quality and Reliability in Distribution System
Arash Bashardoust,Meisam Farrokhifar,Amin Yousefzadeh Fard,Amin Safari,Ehsan Mokhtarpour 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.4
In this paper, network reconfiguration has been conducted to improve the power quality and reliability of distribution systems in presence of distributed generations. In this case, network reconfiguration is analyzed for different indices. The most important indices are the number of propagated voltage sags (N sag), sustained average interruption frequency index, average system interruption frequency index and momentary average interruption frequency index. The Imperialist competitive algorithm (ICA) is hired to find the optimal configuration of the distribution system in order to minimize the mentioned indices. Simulation result is discussed with and without distributed generation.
Robust decentralized control of structures using the LMI H_∞controller with uncertainties
Roya Raji,Ali Hadidi,Hosein Ghaffarzadeh,Amin Safari 국제구조공학회 2018 Smart Structures and Systems, An International Jou Vol.22 No.5
This paper investigates the operation of the H_∞ static output-feedback controller to reduce dynamic responses under seismic excitation on the five-story and benchmark 20 story building with parametric uncertainties. Linear matrix inequality (LMI) control theory is applied in this system and then to achieve the desired LMI formulations, some transformations of the LMI variables is used. Conversely uncertainties due to material properties, environmental loads such as earthquake and wind hazards make the uncertain system. This problem and its effects are studied in this research. Also to decrease the transition of large amount of data between sensors and controller, avoiding the disruption of whole control system and economy problems, the operation of the decentralized controllers is investigated in this paper. For this purpose the comparison between the performance of the centralized, fully decentralized and partial decentralized controllers in uncoupled and coupled cases is performed. Also, the effect of the changing the number of stories in substructures is considered. Based on the numerical results, the used control algorithm is very robust against the parametric uncertainties and structural responses are decreased considerably in all the control cases but partial decentralized controller in coupled form gets the closest results to the centralized case. The results indicate the high applicability of the used control algorithm in the tall shear buildings to reduce the structural responses and its robustness against the uncertainties.
Robust decentralized control of structures using the LMI H<sub>∞</sub>controller with uncertainties
Raji, Roya,Hadidi, Ali,Ghaffarzadeh, Hosein,Safari, Amin Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.22 No.5
This paper investigates the operation of the $H_{\infty}$ static output-feedback controller to reduce dynamic responses under seismic excitation on the five-story and benchmark 20 story building with parametric uncertainties. Linear matrix inequality (LMI) control theory is applied in this system and then to achieve the desired LMI formulations, some transformations of the LMI variables is used. Conversely uncertainties due to material properties, environmental loads such as earthquake and wind hazards make the uncertain system. This problem and its effects are studied in this research. Also to decrease the transition of large amount of data between sensors and controller, avoiding the disruption of whole control system and economy problems, the operation of the decentralized controllers is investigated in this paper. For this purpose the comparison between the performance of the centralized, fully decentralized and partial decentralized controllers in uncoupled and coupled cases is performed. Also, the effect of the changing the number of stories in substructures is considered. Based on the numerical results, the used control algorithm is very robust against the parametric uncertainties and structural responses are decreased considerably in all the control cases but partial decentralized controller in coupled form gets the closest results to the centralized case. The results indicate the high applicability of the used control algorithm in the tall shear buildings to reduce the structural responses and its robustness against the uncertainties.