scholarly journals Rough Sets Non-Deterministic Information Analysis and a NIS-Apriori System – A Rule Generation System Based on Possible World Semantics –

2020 ◽  
Vol 32 (4) ◽  
pp. 747-758
Author(s):  
Hiroshi SAKAI ◽  
Michinori NAKATA ◽  
Junzo WATADA
Keyword(s):  
Rough Sets ◽  
Rule Generation ◽  
Information Analysis ◽  
Generation System ◽  
Possible World ◽  
Possible World Semantics ◽  
System A

scholarly journals Comparative study of a small size wind generation system efficiency for battery charging

2013 ◽  
Vol 10 (2) ◽  
pp. 261-274 ◽  
Author(s):  
Messaoud Mayouf ◽  
Rachid Abdessemed
Keyword(s):  
Control Strategies ◽  
Power Converter ◽  
Maximum Power ◽  
Wind Generation ◽  
Direct Drive ◽  
Generation System ◽  
Battery Charging ◽  
Pulse Width Modulated ◽  
System A ◽  
Wind Generation System

This paper presents an energetic comparison between two control strategies of a small size wind generation system for battery charging. The output voltage of the direct drive PMSG is connected to the battery through a switch mode rectifier. A DC-DC boost converter is used to regulate the battery bank current in order to achieve maximum power from the wind. A maximum powertracking algorithm calculates the current command that corresponds to maximum power output of the turbine. The DC-DC converter uses this current to calculate the duty cycle witch is necessary to control the pulse width modulated (PWM) active switching device (IGPT). The system overview and modeling are presented including characteristics of wind turbine, generator, batteries, power converter, control system, and supervisory system. A simulation of the system is performed using MATLAB/SIMULINK.

scholarly journals A Computational Strategy for Classification of Enem Issues Based on Item Response Theory

2020 ◽  
Vol 27 (1) ◽  
pp. 92-111
Author(s):  
Gustavo Henrique Nunes ◽  
Bruno Alberto Soares Oliveira ◽  
Ciniro Aparecido Leite Nametala
Keyword(s):  
High School ◽  
Item Response Theory ◽  
Item Response ◽  
Generation System ◽  
Response Theory ◽  
Hit Rate ◽  
System A ◽  
Intelligent Simulation ◽  
Computational Strategy

The National High School Examination (ENEM) gains each year more importance, as it gradually, replacing traditional vestibular. Many simulations are done almost randomly by teachers or systems, with questions chosen without discretion. With this methodology, if a test needs to be reapplied, it is not possible to recreate it with questions that have the same difficulty as those used in the first evaluation. In this context, the present work presents the development of an ENEM Intelligent Simulation Generation System that calculates the parameters of Item Response Theory (TRI) of questions that have already been applied in ENEM and, based on them, classifies them. in groups of difficulty, thus enabling the generation of balanced tests. For this, the K-means algorithm was used to group the questions into three difficulty groups: easy, medium and difficult. To verify the functioning of the system, a simulation with 180 questions was generated along the ENEM model. It could be seen that in 37.7% of cases this happened. This hit rate was not greater because the algorithm confounded the difficulty of issues that are in close classes. However, the system has a hit rate of 92.8% in the classification of questions that are in distant groups.

Non-Reductive Materialism and the Spectrum of Mind-Body Theories

Dialogue ◽  
1988 ◽  
Vol 27 (3) ◽  
pp. 475-488 ◽  
Author(s):  
Andrew Kernohan
Keyword(s):  
Identity Theory ◽  
Possible World ◽  
Theory Reduction ◽  
Possible World Semantics ◽  
The Cost

In what follows I will sketch a very simple possible-world semantics which will allow us to sharpen the notion of a non-reductive, but materialist, mind-body identity theory. This simple semantics will enable us to characterize the various possible positions on mind-body identity and display the range of positions with respect to psycho-physical reduction. Though I am sympathetic to a non-reductive position which I label “autonomous monism”, I will be concerned here less with presenting positive arguments for that position than with describing a framework in which such arguments can be made and pointing out the issues that the position raises. The discussion achieves its abstract viewpoint at the cost of slightly idealizing the process of theory reduction, but the overview attained is worth the price.

Codd Table Representations under Weak Possible World Semantics

2011 ◽  
pp. 125-139 ◽  
Author(s):  
Flavio Ferrarotti ◽  
Sven Hartmann ◽  
Van Bao Tran Le ◽  
Sebastian Link
Keyword(s):  
Possible World ◽  
Possible World Semantics

scholarly journals The Virtual Harmonic Power Droop Strategy to Mitigate the Output Harmonic Voltage of the Inverter

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2196 ◽  
Author(s):  
Yuan Yao ◽  
Longyun Kang
Keyword(s):  
Distributed Generation ◽  
Second Order ◽  
Droop Control ◽  
Virtual Power ◽  
Generation System ◽  
System A ◽  
Common Control ◽  
Harmonic Voltage ◽  
The Mathematical Model ◽  
Harmonic Power

The harmonic voltage issue becomes a challenge for a distributed generation system. Considering that droop control is the most common control algorithm used in the distributed system, a virtual harmonic power droop strategy which aims to mitigate the harmonic voltage is proposed in this paper. First, the conventional droop control is analyzed. Based on that concept, the virtual power algorithm is introduced. Second, the output harmonic voltage issue and the mathematical model of the inverter are presented. In addition, the second-order generalized integrator is briefly discussed. Third, taking into consideration the algorithms and models presented, a virtual harmonic power droop strategy is proposed to implement the harmonic voltage mitigation. In this algorithm, signals in fundamental frequency and harmonic frequency are separated with the help of second-order generalized integrators. Unlike the conventional voltage–current dual loop structure which is used to mitigate system harmonics, this method only needs the virtual power feedback to mitigate the harmonic voltage. Based on these features, the system’s control structure is simplified. Simulation and experimental results verified the harmonic voltage mitigation ability of the proposed strategy.

Sign in / Sign up

Export Citation Format

Share Document