Nhu Lan Vu

Vietnam Academy of Science and Technology and Thang Long University · Thang Long University

Instead of handling fuzzy sets associated with linguistic (L-) labels based on the developers’ intuition immediately, the study follows the hedge algebras (HA-) approach to the time series forecasting problems, in which the linguistic time series forecasting model was, for the first time, proposed and examined in 2020. It can handle the declared fo...

The algebra theory was developed by the group of authors in the 1990s and has had a great deal of application in various fields, such as information technology, image processing, control and automation. This paper presents the application of hedge algebras based on fuzzy logic to control TRMS, including the construction of the hedge-algebras-argume...

This paper considers a stand-alone wind energy conversion system (WECS) designed for dc load supply and battery charging. An indirect rotor-field-oriented (IRFO) control scheme is applied for the wind turbine (WT) driven induction generator (IG). High level of agreement between the actual IG and the IRFO controller is ensured by including the IG st...

Fuzzy time series forecasting model was first introduced by Song and Chissom, in 1993. Then, Chen examined this model, in 1996, applying fuzzy rules in the form Ai → Aj , where Ai and Aj are fuzzy sets associated with linguistic labels representing their corresponding values in a time series. Since then, many methods have been proposed to improve t...

This paper deals with a variable-speed wind energy conversion system (WECS), which is designed for dc load supply and battery charging in stand-alone applications. The PI speed controller, which is typically used in vector control systems with a self-excited induction generator (SEIG), is here replaced with a hedge-algebra controller (HAC). With th...

Dealing with the time series forecasting problem attracts much attention from the fuzzy community. Many models and methods have been proposed in the literature since the publication of the study by Song and Chissom in 1993, in which they proposed fuzzy time series together with its fuzzy forecasting model for time series data and the fuzzy formalis...

In the Internet of Things era, Wireless Sensor Network (WSN) acts as a key infrastructure, provides a large number of outstanding applications nowadays. WSN is a distributed and self-organizing wireless network with lots of constraint issues such as communication capacity, energy limitation, and distributed fashion. This type of wireless network is...

In model predictive control (MPC), it is particularly important to construct a precise modeling of the control as it is decisive to quality and control accuracy. The paper proposes a combination of the Takagi-Sugeno fuzzy model and the hedge algebra to construct a new fuzzy model called the Takagi-Sugeno-Hedge Algebras. This hybrid model develops t...

This paper presents the first application of the hedge-algebra theory in the field of grid synchronization. For this purpose, an optimized hedge-algebra controller (HAC) is developed and incorporated within the three-phase phase-locked loop (PLL) with moving average filters (MAFs) inside its feedback loop. Optimized fuzziness parameters and linguis...

networks is one of the most research issues in recent years. Clustering strategy based on Low-Energy Adaptive Clustering Hierarchy (LEACH) can provide a good performance on the energy efficiency aspects. In which, fuzzy logic based on LEACH is suitable to adapt uncertain conditions in decision actions such as cluster formation and cluster head elec...

Building fuzzy associate memory accordance with control problems has great meaning for control methods In this paper we propose a method, that build fuzzy associate memory for control problem based on optimal trajectory of control problem, the method developed by theory hedge algebras and genetic algorithm.

Fuzzy time series given by Song & Chissom (1993) in magazine "Fuzzy Sets and Systems" has been widely studied for forecasting purposes. However, the accuracy of forecasts based on the concept of fuzzy approach of Song & Chissom is not high because of such depends on many factors. Chen (1996) proposed an efficient fuzzy time series model which consi...

The report aims to show that hedge algebras model actually the proper qualitative semantics of words of linguistic variables based on the argument that the inherent qualitative semantics of words should be expressed through the order relationships between the words in their respective variable domains induced by the word semantics, as it is requ...

Hedge algebras (HAs) theory has been extensively developed with many effective applications in different fields of fuzzy theory such as data mining, fuzzy database system, fuzzy reasoning, and so on. We propose here a general design method of hedge-algebras-based fuzzy controllers (HACs) for a potential application in structural active control. The...

Forecasting on fuzzy times series has researched by many reseachers such as Q. Song, B.S. Chissom, S. M. Chen… There are many methods have researched and presented to handle and improve the results of forcasting method that were introduced by Q. Song, B.S. Chissom and S.M. Chen. Those methods have MSE (Mean Square Error) increasely lower. During re...

This paper presents an indirect rotor-field-oriented (IRFO) control system of the self-excited induction generator (SEIG) in which the excitation is achieved by means of a current-controlled voltage source inverter (CC-VSI) and a single electrolytic capacitor. In the proposed control scheme, both the iron losses and the magnetic saturation are take...

Động cơ một chiều là một đối tượng điều khiển quan trọng do được ứng dụng rất rộng rãi cho nhiều lĩnh vực khác nhau. Vì vậy điều khiển động cơ một chiều được nhiều tác giả trên thế giới quan tâm, trong đó bộ điều khiển PI thường được sử dụng.Bộ điều khiển mờ cũng được sử dụng thay thế cho bộ điều khiển PI để đảm bảo tính mềm dẻo trong quá trình điề...

Active control problems of seismic-excited civil structures have attracted considerable attention in recent years. In this study, a design procedure of the hedge algebra-based fuzzy controller (HAFC) is investigated for a class of high-rise building systems with active tendons, which are subjected to seismic activity. In the HAFC, semantics of ling...

In this paper, three controllers, including OFCHA (optimal fuzzy control using hedge algebras – HAs), FCHA (fuzzy control using HAs) and CFC (conventional fuzzy control) are designed. Attention is paid to the stability in the vertical position of a damped-elastic-jointed inverted pendulum subjected to a time-periodic follower force. The different v...

The active control problem of seism-excited civil structures has attracted considerable attention in recent years. In this paper, conventional, hedge-algebras-based and optimal hedge-algebras-based fuzzy controllers, respectively denoted by HAFCs and OHAFCs, are designed to suppress vibrations of a structure against earthquake. The interested struc...

The main purpose of the chapter is to introduce a new methodology for the design of fuzzy controller based on hedge-algebras approach. Hedge algebras can be regarded as natural models of terms-domains of linguistic variable, whose elements in the form of string express directly vague terms. Thus, the hedge-algebras approach seems to be appropriate...

In this paper, we introduce a hedge-algebras-based methodology in fuzzy vibration control of structural systems to design fuzzy controllers, referred to as hedge-algebras-based controllers (HACs). In this methodology, vague linguistic terms are not expressed by fuzzy sets, but by inherent order relationships between vague terms existing in a term-d...

Active control problems of seismic-excited civil structures have attracted considerable attention in recent years. In this study, a design procedure of the hedge algebra-based fuzzy controller (HAFC) is investigated for a class of high-rise building systems with active tendons, which are subjected to seismic activity. In the HAFC, semantics of ling...

In this paper, three controllers, including OFCHA (optimal fuzzy control using hedge algebras – HAs), FCHA (fuzzy control using HAs) and CFC (conventional fuzzy control) are designed. Attention is paid to the stability in the vertical position of a damped-elastic-jointed inverted pendulum subjected to a time-periodic follower force. The different v...

The unique mathematical structure for modeling the inherent semantics-based structure of term-domains of linguistic variables is the algebraic structure of hedge algebras. With this regard, hedge algebras offers a possibility to define and develop many significant concepts including fuzziness and fuzziness measure of erms, fuzziness intervals, k-si...

In this paper, three controllers including OFCHA (optimal fuzzy control using hedge algebras -HAs), FCHA (fuzzy control using HAs) and CFC (conventional fuzzy control) are designed. Our attention is paid to the stability in the vertical position of a damped-elastic-jointed inverted pendulum subjected to a time periodic follower force. Different val...

In this work, we propose a new method able to find fuzzy IF-THEN rules from input output observations based on hedge algebras and apply this method to the Fan & Plate control problem (modelPP200). In fact, hedge algebras-based controller (HAC), formulated on the basis of human knowledge about the processor identified from measured control action, c...

In previous papers, we introduced a new reasoning method based on quantifying linguistic domains, established a new fuzzy control algorithm, called hedge-algebras-based controller (HAC), and applied it to solve some fuzzy control problems. The HAC does not require fuzzy sets to provide the semantics of the linguistic terms used in the fuzzy rule sy...

The paper aims to present the way term-domains regarded as hedge algebras can be quantified and show an applicability of this quantification of hedge algebras, which were introduced and examined in [7,9,11,6], in solving some problems of fuzzy control. In this algebraic approach, linearly ordered term-domains of linguistic variables can be consider...

The paper aims to show an applicability of the algebraic approach introduced in [7,9,11,6] to solving a problem of fuzzy control. In this approach, linearly ordered term-domains of linguistic variables can be considered as linear hedges algebras (LinHAs). It is interesting that in LinHAs, a formal notion of fuzziness measure of linguistic hedges an...