다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

1. Interaction. The interactions learners have with each other build interpersonal skills, such as listening, politely interrupting, expressing ideas, raising questions, disagreeing, paraphrasing, negotiating, and asking for help. 2. Interdependence. Learners must depend on one another to accomplish a common objective. Each group member has specific tasks to complete, and successful completion of each member’s tasks results in attaining the overall group objective.

将“Cooperative Learning”融入课堂——浅谈英语素质教育

Solar Engineering Of Thermal Processes

The recently introduced proportional-resonant (PR) controllers and filters, and their suitability for current/voltage control of grid-connected converters, are described. Using the PR controllers, the converter reference tracking performance can be enhanced and previously known shortcomings associated with conventional PI controllers can be alleviated. These shortcomings include steady-state errors in single-phase systems and the need for synchronous d-q transformation in three-phase systems. Based on similar control theory, PR filters can also be used for generating the harmonic command reference precisely in an active power filter, especially for single-phase systems, where d-q transformation theory is not directly applicable. Another advantage associated with the PR controllers and filters is the possibility of implementing selective harmonic compensation without requiring excessive computational resources. Given these advantages and the belief that PR control will find wide-ranging applications in grid-interfaced converters, PR control theory is revised in detail with a number of practical cases that have been implemented previously, described clearly to give a comprehensive reference on PR control and filtering.

Proportional-resonant controllers and filters for grid-connected voltage-source converters

Recent advancements in supercapacitor technology

Singularity Characterization of DAE Systems Appearing in Constrained Robotic Systems

Frequency Response

Toyota Mirai is a widely known fuel cell hybrid vehicle and its powertrain represents a benchmark for engineers and researchers. This work presents a lumped-parameter low-order model of Toyota Mirai powertrain and an assessment of the energy management focused on fuel economy and battery and fuel cell degradation. In addition, a rule-based strategy is proposed to reproduce the behavior of Toyota Mirai energy management strategy. The powertrain model and the proposed strategy are validated against experimental data. The assessment of the energy management is performed by comparing the Toyota Mirai strategy with optimal strategies obtained offline via dynamic programming. Different optimal strategies are computed by including the demand of the fuel cell and the battery in the cost function. Simulation results show a high correlation between the proposed model and strategy compared to the experimental data. Comparison of Toyota Mirai strategy with the optimal strategies reveals a small margin for improvement in fuel economy and higher margins in terms of demand of the fuel cell and battery.

Toyota Mirai: Powertrain Model and Assessment of the Energy Management

A Virtual Sensor for a Cell Voltage Prediction of a Proton-Exchange Membranes Based on Intelligent Techniques.

Shunt active power filters have been introduced as a way to overcome the power quality problems caused by nonlinear and reactive loads [9, 14, 23]. These power electronics devices are designed with the goal of obtaining a power factor close to 1 and achieving current harmonics and reactive power compensation [5, 6, 15]. The usual approaches [5, 15] for the control of shunt active filters are based on two hierarchical control loops: an inner one that assures the desired current and an outer one in charge of determining its required shape and the appropriate power balance as well. The control structure followed in this Chapter is the one in [7], in which the current controller is composed of a feedforward action that provides very fast transient response, and also of a feedback loop which includes an odd-harmonic repetitive control that yields closed-loop stability and a very good harmonic correction performance. In turn, the outer control law is based on the appropriated computation of the amplitude of the sinusoidal current network and, aiming at a robustness improvement, this is combined with a feedback control law including an analytically tuned PI controller.

Ramon Costa-Castelló

Papers

Singularity Characterization of DAE Systems Appearing in Constrained Robotic Systems

Frequency Response

Toyota Mirai: Powertrain Model and Assessment of the Energy Management

A Virtual Sensor for a Cell Voltage Prediction of a Proton-Exchange Membranes Based on Intelligent Techniques.

Shunt Active Power Filter