scholarly journals Principles of the Proposed Czech Postal Sector Price Control Model

1970 ◽  
Vol 21 (1) ◽  
pp. 33-40
Author(s):  
Libor Švadlenka ◽  
Aleksander Chlan

The paper deals with the postal sector control. It resultsfrom the control theory and proves the justifiability of control inthe postal sector. Within the price control it results from E U Directive97!67/EC requirements on this control and states individualtypes of price control focusing on ineffective price controlcurrently used in the Czech postal sector (especially withindomestic services) and proposes a more effective method ofprice control. The paper also discusses the principles of the proposedmethod of price control of the Czech postal sector. It describesconcrete fulfilment of the price control model resultingfrom the price-cap and tariff formula RP I-X and concentrateson its quantitative expression. The application of the proposedmodel is carried out for a hypothetical period in the past (in orderto compare it with the current control system) for letteritems tariff basket.

2018 ◽  
Vol 138 (11) ◽  
pp. 848-856
Author(s):  
Sari Maekawa ◽  
Mariko Sugimoto ◽  
Keiichi Ishida ◽  
Masaya Nogi ◽  
Masaki Kanamori

Author(s):  
Qixin Zhu ◽  
Lei Xiong ◽  
Hongli Liu ◽  
Yonghong Zhu ◽  
Guoping Zhang

Background: The conventional method using one-degree-of-freedom (1DOF) controller for Permanent Magnet Synchronous Motor (PMSM) servo system has the trade-off problem between the dynamic performance and the robustness. Methods: In this paper, by using H∞ control theory, a novel robust two-degree-of-freedom (2DOF) controller has been proposed to improve the position control performance of PMSM servo system. Using robust control theory and 2DOF control theory, a H∞ robust position controller has been designed and discussed in detail. Results: The trade-off problem between the dynamic performance and robustness which exists in one-degree-of-freedom (1DOF) control can be dealt with by the application of 2DOF control theory. Then, through H∞ control theory, the design of robust position controller can be translated to H∞ robust standard design problem. Moreover, the control system with robust controller has been proved to be stable. Conclusion: Further simulation results demonstrate that compared with the conventional PID control, the designed control system has better robustness and attenuation to the disturbance of load impact.


Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 146
Author(s):  
Jordan Hoffman ◽  
Ilinca Ciubotariu ◽  
Limonty Simubali ◽  
Twig Mudenda ◽  
William Moss ◽  
...  

Despite dramatic reductions in malaria cases in the catchment area of Macha Hospital, Choma District, Southern Province in Zambia, prevalence has remained near 1–2% by RDT for the past several years. To investigate residual malaria transmission in the area, this study focuses on the relative abundance, foraging behavior, and phylogenetic relationships of Anopheles squamosus specimens. In 2011, higher than expected rates of anthropophily were observed among “zoophilic” An. squamosus, a species that had sporadically been found to contain Plasmodium falciparum sporozoites. The importance of An. squamosus in the region was reaffirmed in 2016 when P. falciparum sporozoites were detected in numerous An. squamosus specimens. This study analyzed Centers for Disease Control (CDC) light trap collections of adult mosquitoes from two collection schemes: one performed as part of a reactive-test-and-treat program and the second performed along a geographical transect. Morphological identification, molecular verification of anopheline species, and blood meal source were determined on individual samples. Data from these collections supported earlier studies demonstrating An. squamosus to be primarily exophagic and zoophilic, allowing them to evade current control measures. The phylogenetic relationships generated from the specimens in this study illustrate the existence of well supported clade structure among An. squamosus specimens, which further emphasizes the importance of molecular identification of vectors. The primarily exophagic behavior of An. squamosus in these collections also highlights that indoor vector control strategies will not be sufficient for elimination of malaria in southern Zambia.


2021 ◽  
Vol 13 (11) ◽  
pp. 6388
Author(s):  
Karim M. El-Sharawy ◽  
Hatem Y. Diab ◽  
Mahmoud O. Abdelsalam ◽  
Mostafa I. Marei

This article presents a control strategy that enables both islanded and grid-tied operations of a three-phase inverter in distributed generation. This distributed generation (DG) is based on a dramatically evolved direct current (DC) source. A unified control strategy is introduced to operate the interface in either the isolated or grid-connected modes. The proposed control system is based on the instantaneous tracking of the active power flow in order to achieve current control in the grid-connected mode and retain the stability of the frequency using phase-locked loop (PLL) circuits at the point of common coupling (PCC), in addition to managing the reactive power supplied to the grid. On the other side, the proposed control system is also based on the instantaneous tracking of the voltage to achieve the voltage control in the standalone mode and retain the stability of the frequency by using another circuit including a special equation (wt = 2πft, f = 50 Hz). This utilization provides the ability to obtain voltage stability across the critical load. One benefit of the proposed control strategy is that the design of the controller remains unconverted for other operating conditions. The simulation results are added to evaluate the performance of the proposed control technology using a different method; the first method used basic proportional integration (PI) controllers, and the second method used adaptive proportional integration (PI) controllers, i.e., an Artificial Neural Network (ANN).


1968 ◽  
Vol 1 (8) ◽  
pp. T.129-T.132 ◽  
Author(s):  
F. M. Toates

The reciprocal interaction between the accommodation and pupil control systems of the human eye is examined from a theoretical point of view. The system, which is responsible for maintaining pupil diameter at a value which is a compromise between conflicting requirements, is represented by a control model, and is considered in terms of the concept of a performance index.


2013 ◽  
Vol 706-708 ◽  
pp. 716-719
Author(s):  
Jian Chu ◽  
Gang Wang

This paper mainly introduced to the PLC as the core of stainless steel composite plate electric control part of the design. The system uses the converter +PLC+ man-machine interface, as the major part of roll welding machine control, because of the use of the PLC, so that the system can improve the automatic level, electrical components is reduced, reduce failure rate, improve the reliability of equipment operation. Based on the current control and speed control, so that the welding quality and welding speed has been greatly improved. In the article, mainly from the production process, and the control system hardware and software design, and the control scheme to introduce several aspects.


2014 ◽  
Vol 548-549 ◽  
pp. 819-823
Author(s):  
Xi Juan Wang ◽  
Tao Zhou ◽  
Jing Xiao Feng ◽  
Yu Peng Pei

In the AC control system, vector control theory is very popular as it makes the AC motor achieve the performance as perfect as DC motor [1]. In the paper, the vector control theory is briefly introduced, and then a vector control system model is builded in the matlab/simulink, and the SVPWM technique is adopted. The results show that the improved vector control sytem of PMSM has a excellent performance.


2010 ◽  
Vol 455 ◽  
pp. 206-210
Author(s):  
Jun Li Liu ◽  
Yan Yan Yan ◽  
G.Q. He

It discusses the reasons of the data transmission time delay and packets loss based on the theory of net data transmission. Aimed to the question of the time delay of data transmission and packets loss, the control system models are set up to analyze their influence to the performance of the control system. Based on the synchronous control model analysis with wireless data transmission, a method to control the system is reached with the state prediction when the communication error or data loss appears. It can control constantly when communication errors appear, and also it can get the most error period by numerical analysis.


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