University of Macau

About: University of Macau is a education organization based out in Macao, Macau, China. It is known for research contribution in the topics: Population & Control theory. The organization has 6636 authors who have published 18324 publications receiving 327384 citations. The organization is also known as: UM & UMAC.

Analysis, Design, and Implementation of a Quasi-Proportional-Resonant Controller for a Multifunctional Capacitive-Coupling Grid-Connected Inverter

Abstract: The capacitive-coupling grid-connected inverter (CGCI) is coupled to the point of common coupling via a second-order LC branch. Its operational voltage is much lower than that of a conventional inductive-coupling grid-connected inverter (IGCI) when it serves as a multifunctional inverter to compensate reactive power and transfer active power simultaneously. It is a promising solution for microgrid and building-integrated distributed generator systems. A quasi-proportional-resonant (quasi-PR) controller is applied to reduce the steady-state current tracking errors of the CGCI in this paper. The quasi-PR controller generates the voltage reference for use of carrier-based pulse-width modulation, which can effectively reduce output current ripples. The second-order coupling impedance of the CGCI causes its modeling and controller design to differ from that of the conventional IGCI. A comprehensive design method for the quasi-PR controller in a CGCI is developed. The quasi-PR controller is also compared with a proportional-integration current controller. Simulation results are provided to verify the effectiveness of the quasi-PR controller and its design method in a CGCI. The current tracking errors are greatly reduced when the quasi-PR controller rather than the proportional-integration controller is applied. Experimental results are also provided to validate the CGCI as a multifunctional grid-connected inverter.

Worldwide Differences in Regulations of Clozapine Use.

Abstract: Clozapine remains the drug of choice for treatment-resistant schizophrenia. As a consequence of its long history and complex pharmacology, we suspected wide variation in the regulations of clozapine use across different countries. The summaries of product characteristics (SPCs) from clozapine manufacturers, as well as local and national guidelines in the following selected countries, were reviewed: China, Denmark, Ireland, Japan, The Netherlands, New Zealand, Romania, the UK and the US. Clozapine is available as tablets in all countries, as an oral suspension in all included countries, with the exception of Japan and Romania, as orally disintegrating tablets in the US and China, and as an injectable in The Netherlands. General practitioner prescribing is only available in The Netherlands, New Zealand, the UK and the US, although with some restrictions in some of the countries. In Ireland and China, clozapine is only dispensed through hospital pharmacies. Hematological monitoring is mandatory in all countries but varies substantially in frequency, e.g. in Denmark hematologic monitoring is mandatory weekly for 18 weeks, followed by monthly monitoring, compared with Japan where blood work is required weekly for 26 weeks, followed by biweekly hematologic monitoring thereafter. In most included countries, with the exception of Denmark, Romania and The Netherlands, the manufacturer provides a mandatory hematological monitoring database, and dispensing of clozapine is not permissible without acceptable white blood count and absolute neutrophil count results. Local guidelines in New Zealand recommend echocardiography and routine troponin during the initial phases of treatment with clozapine. Regulations of clozapine vary widely with regard to rules of prescribing and monitoring. A worldwide update and harmonization of these regulations is recommended.

Distributed Time-Sensitive Task Selection in Mobile Crowdsensing

Abstract: With the rich set of embedded sensors installed in smartphones and the large number of mobile users, we witness the emergence of many innovative commercial mobile crowdsensing applications that combine the power of mobile technology with crowdsourcing to deliver time-sensitive and location-dependent information to their customers. Motivated by these real-world applications, we consider the task selection problem for heterogeneous users with different initial locations, movement costs, movement speeds, and reputation levels. Computing the social surplus maximization task allocation turns out to be an NP-hard problem. Hence we focus on the distributed case, and propose an asynchronous and distributed task selection (ADTS) algorithm to help the users plan their task selections on their own. We prove the convergence of the algorithm, and further characterize the computation time for users' updates in the algorithm. Simulation results suggest that the ADTS scheme achieves the highest Jain's fairness index and coverage comparing with several benchmark algorithms, while yielding similar user payoff to a greedy centralized benchmark. Finally, we illustrate how mobile users coordinate under the ADTS scheme based on some practical movement time data derived from Google Maps.