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This paper introduces a novel control approach for Doubly-Fed Induction Generator (DFIG) operating in island mode based on the cascaded control structure with disturbance estimation. The control of the DFIG is a challenging task due to its inherent nonlinearity, fast dynamics, and unpredictable disturbances acting on the system. The proposed control structure involves a nominal controller for plant and disturbance observer (DOB) in each of the inner and outer control loop. The first-order disturbance observers are designed to estimate the time-varying and unknown disturbances. With disturbance estimation, the nominal linear dynamics is obtained in both loops. This enables the same approach for designing controllers for the inner and outer loop which significantly simplifies implementation. The controllers are designed based on the demanded error dynamics and ensure stable operation of the system, while proposed DOBs estimate disturbances including external load. Finally, the effectiveness and quality of the proposed control structure were verified through numerical simulations in terms of external disturbances rejection and closed-loop tracking performance.

E. Sariyildiz, Satoshi Hangai, T. Uzunović, Takahiro Nozaki

This paper analyses Disturbance Observer- (DOb-) based robust force control systems in the discrete-time domain. The robust force controller is implemented using velocity and acceleration measurements. A DOb is employed in an inner-loop to achieve robustness, and another DOb, viz. Reaction Force Observer (RFOb), is employed in an outer-loop to estimate interaction forces and improve the performance of force control. First, the inner-loop is analysed. It is shown that the DOb works as a phase-lead/lag compensator tuned by the nominal design parameters in the inner-loop. The phase margin of the inner-loop controller and the bandwidth of the velocity-based (i.e., conventional) DOb are constrained not only by noise-sensitivity but also by the waterbed effect. This explains why we observe unstable responses as the bandwidth of the conventional DOb increases in practice. To eliminate the design constraint due to the waterbed effect, this paper proposes an acceleration-based DOb. Then, the robust force controller is analysed. It is shown that the design parameters of the RFOb have a notable effect on the stability of the robust force control system. For example, the robust force controller has a non-minimum phase zero (zeros) when the RFOb is not properly tuned. This may cause severe stability and performance problems when conducting force control applications. By using the stability and robustness analyses, this paper proposes new design tools which enable one to synthesize a high-performance robust force control system. Simulations and experiments are presented to validate the proposed analysis and synthesis methods.

Ahmed Al-Saffar, Alina Bialkowski, Mahsa Baktashmotlagh, A. Trakic, Lei Guo, A. Abbosh

Bringing deep learning techniques to electromagnetic imaging is of interest considering its great success in various fields. Deep neural nets however are known for being data hungry machines, and in many practical cases, such as electromagnetic medical imaging, there is not enough to feed them. Scarcity of data necessitates reliance on simulations to generate a sufficiently large dataset for deep learning to perform any complicated task. Simulations however, can not perfectly represent real environments and therefore, any neural net trained on simulation data will invariably fail when evaluated on real data. This work customizes a deep domain adaptation technique for matching distributions of complex-valued electromagnetic data. We demonstrate the advantage of using complex-valued models over regular ones. An operational neural network trained on simulation data and adapted to practical data to perform brain injury localization is presented.

Hamza Bourbouh, M. Farrell, Anastasia Mavridou, Irfan Šljivo, G. Brat, Louise Dennis, M. Fisher

Fabrizio Lombardi, Selver Pepic, O. Shriki, G. Tkačik, Daniele De, Martino

Sanja Bajgorić, Muris Đug

The research was conducted in order to determine the differences in situational-motor abilities in the defense of men's junior national teams at the 2013 World Handball Championship. Situational - motor abilities in the defense of the national team of Bosnia and Herzegovina in relation to the national teams of Croatia, France, Sweden and Spain were analyzed. The following variables were used to determine differences in defense: SKODEKUK / PR - total - average number of jumps in defense of the whole team, SKODUK / PR1 - total - average number of jumps in defense first player of defense, SKODUK / PR2 - total - average number of jumps in defense second defensive player, SKODUK / PR3 - total - average number of defensive jumps third defensive player, SKODUK / PR4 - total - average number of defensive jumps fourth defensive player, SKODUK / PR5 - total - average number of defensive jumps fifth defensive player and SKODUK / PR6 - total - average number of jumps in the sixth defense player. To determine the partial quantitative differences of variables, which measure the total and average number of attempts to perform an element in the area of situational - motor abilities in defense, we used the mean difference of mean (hereinafter MD), which calculated the average values of selected variables. The average values of variables for the assessment of situational - motor abilities in defense were also calculated. The variable SKODUK / PR4 - total - average number of jumps in the defense of the fourth player shows a statistically significant negative difference in the jumps in the defense of the fourth player between the fourth player in the defense of Bosnia and Herzegovina and the fourth player in the defense of Croatia and Sweden. In the variable SKODUK / PR6 - total - average number of jumps in the defense of the sixth defense player, a statistically significant negative difference can be seen between the sixth player in the defense of the national team of Bosnia and Herzegovina and the sixth player in the defense of Sweden. Key words: handball, juniors, World Championship, defense, situational - motor abilities

S. Štrbac, Nataša Pilipović-Broćeta, Nevena Todorović, V. vujić-Aleksić, Siniša Stević, A. Lolić, A. Šeranić, D. Vulic et al.

Background/Aim: The prevention of cardiovascular risk factors and cardiovascular disease management contributes to the cardiovascular mortality reduction. The effects of these activities have been measured by quality indicators. The aim of this study was to determine the effects of family medicine team training workshop and implementation of clinical guidelines on the cardiovascular risk factors and diseases management in primary health care in the Republic of Srpska/Bosnia and Herzegovina. Methods: The "CardioVascular Risk Assessment and Management" study included a sample of 373 teams from 41 primary health care centres trained to provide adequate services and to compare the quality of cardiovascular risk management before and after the training workshop and implementation of clinical guidelines. The comparison was based on nine project defined performance indicators related to hypertension, type 2 diabetes mellitus, hyperlipidaemia, tobacco smoking and obesity. Results: Significant improvements were observed in six indicators after the training workshop and implementation of guidelines. Target values for blood pressure and HbA1c were achieved in over 80 % of patients (82.12 ± 15.81 vs 84.49 ± 12.71 and 84.49 ± 12.71 vs 85.49 ± 24.55; before and after the training workshop, respectively), while the target values for LDL cholesterol were achieved in 54.98 % ± 20.33 before and 57.64 % ± 16.66 after the training workshop. The number of teams that had less than 20 % of recorded data significantly decreased after the training workshop and guidelines implementation, and adequate recording of all indicators was improved. Conclusion: The training workshop of family medicine teams and implementation of clinical guidelines resulted in significant quality improvement of cardiovascular diseases management in primary health care.

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