Functions of the category of combinatorial geometries and strong maps

AbstractThe motivation of this study was to prove the following conjecture by Rota: Given a pregeometry G(r, s) and an integer k ⩾ 1, the geometrization of the function kr is a functor of the category of finite pregeometries and strong maps into itself. In addition to a proof of this fact, properties of other classes of functors based on expansions and geometrizations are presented in this paper

On tracking control problem for polysolenoid motor model predictive approach

The Polysolenoid Linear Motor (PLM) have been playing a crucial role in many industrial aspects due to its functions, in which a straight motion is provided directly without mediate mechanical actuators. Recently, with several commons on mathematic model, some control methods for PLM based on Rotational Motor have been applied, but position, velocity and current constraints which are important in real systems have been ignored. In this paper, position tracking control problem for PLM was considered under state-independent disturbances via min-max model predictive control. The proposed controller forces tracking position errors converge to small region of origin and satisfies state including position, velocity and currents constraints. Further, a numerical simulation was implemented to validate the performance of the proposed controller

The Prominent Role of Hat Chap Cai Luong Arts in Tourist Attraction to Thoi Son Island, Tien Giang Province

The purpose of this article is to study and analyze the current development and utilization of cultural and artistic tourism products on Thoi Son Island, Tien Giang Province. The article focuses on evaluating the effectiveness of incorporating don ca tai tu music (a genre of chamber music in the traditional music of southern Vietnam) in serving tourism activities in recent times and identifying existing issues in the development process of these cultural and artistic tourism products. In addition to discussing the advantages and competitive capabilities of Thoi Son Island, the article also proposes suitable solutions for the development of cultural and artistic tourism products in the locality, particularly the application and promotion of the art of hat chap cai luong (one of the traditional theater opera plays in southern Vietnam) combined with storytelling for tourism purposes. The research methodology employed in the article combines both quantitative and qualitative approaches. The quantitative part of the research will concentrate on collecting data on tourist numbers, income from cultural and artistic tourism activities, and tourist satisfaction. The qualitative part will involve conducting interviews, surveys, and gathering opinions from experts and local residents to gain a better understanding of the issues related to cultural and artistic tourism products featuring cai luong singing on Thoi Son Island. The research findings indicate that incorporating the art of hat chap cai luong into tourism activities is effective. However, several issues have been identified that need to be addressed, such as diversifying cultural and artistic tourism products, protecting and promoting the local cultural values, and ensuring the ability to meet the future demand for cultural tourism products without causing har

Radial basis function neural network control for parallel spatial robot

The derivation of motion equations of constrained spatial multibody system is an important problem of dynamics and control of parallel robots. The paper firstly presents an overview of the calculating the torque of the driving stages of the parallel robots using Kronecker product. The main content of this paper is to derive the inverse dynamics controllers based on the radial basis function (RBF) neural network control law for parallel robot manipulators. Finally,  numerical simulation of the inverse dynamics controller for a 3-RRR delta robot manipulator is presented as an illustrative example

Prioritizing Key Success Factor of the Internet of Things Application in Tourism Enterprise

Purpose: The objective of this study is to explore critical success factors in Internet of Things applying and their importance level in tourism companies using the fuzzy theory.   Theoretical framework: This paper uses the TOE framework and adds a customer security variable. Therefore, the framework includes four variables technology, organization, environment, and customer security (TOEC) which are the four aspects of this research framework.   Design/methodology/approach: By integrating FAHP and FAHP extension methods, the study finds that the critical success factors for IoT application in tourism companies, including technology, organization, environment, and customer security.   Findings: The result show that, the first ranking is organization factor, the second ranking belongs to technology, customer securities come with third ranking, and the fourth ranking is environment. This result also indicates that IT Human resources, Technology infrastructure, Top management support, and organization readiness are the prioritized critical success factors for IoT applications in tourism companies.   Research, Practical & Social implications: This paper contributes to the understanding of IoT, its features and highlights the importance of new technology and solutions in tourism industry.   Originality/value: This study fills the gap in the TEO model by adding the factor of customer securities so-called TEOC model

Design Low Order Robust Controller for the Generator’s Rotor Angle Stabilization PSS System

The electrical system's problem stabilizes the electrical system with three primary parameters: rotor angle stability, frequency stability, and voltage stability. This paper focuses on the problem of designing a low-order stable optimal controller for the generator rotor angle (load angle) stabilization system with minor disturbances. These minor disturbances are caused by lack of damping torque, change in load, or change in a generator during operation. Using the RH∞optimal robust design method for the Power System Stabilizer (PSS) to stabilize the generator’s load angle will help the PSS system work sustainably under disturbance. However, this technique's disadvantage is that the controller often has a high order, causing many difficulties in practical application. To overcome this disadvantage, we propose to reduce the order of the higher-order optimal robust controller. There are two solutions to reduce order for high-order optimal robust controller: optimal order reduction according to the given controller structure and order reduction according to model order reduction algorithms. This study selects the order reduction of the controller according to the model order reduction algorithms. In order to choose the most suitable low-order optimal robust controller that can replace the high-order optimal robust controller, we have compared and evaluated the order-reducing controllers according to many model order reduction algorithms. Using robust low-order controllers to control the generator’s rotor angle completely meets the stabilization requirements. The research results of the paper show the correctness of the controller order reduction solution according to the model order reduction algorithms and open the possibility of application in practice. Doi: 10.28991/esj-2021-01299 Full Text: PD

Effect of System of Rice Intensification（SRI）on growth and yield performance in Nam Dong district, Thua Thien Hue province, Vietnam

The field study was conducted in Nam Dong district, Thua Thien Hue province, Vietnam during May 2019 to observe the effects of SRI method on the rice yield and eradicate the factor affecting the yield. The study was carried out to evaluate the agronomic characteristics of rice, fresh and dry matter production, soil characteristics with a focus group discussion regarding cultivation by SRI and non-SRI methods. The soil analyses using standard measurements showed quite similar soil fertility in both SRI and non-SRI methods, while rice plants showed good agronomic performances and fresh and dry matter production in SRI method. At harvesting time, the yield and yield potentials of rice were greater in SRI than that in non-SRI methods. Focus group discussion found some factors that limited SRI development in Nam Dong district

Addressing Non-IID Problem in Federated Autonomous Driving with Contrastive Divergence Loss

Federated learning has been widely applied in autonomous driving since it enables training a learning model among vehicles without sharing users' data. However, data from autonomous vehicles usually suffer from the non-independent-and-identically-distributed (non-IID) problem, which may cause negative effects on the convergence of the learning process. In this paper, we propose a new contrastive divergence loss to address the non-IID problem in autonomous driving by reducing the impact of divergence factors from transmitted models during the local learning process of each silo. We also analyze the effects of contrastive divergence in various autonomous driving scenarios, under multiple network infrastructures, and with different centralized/distributed learning schemes. Our intensive experiments on three datasets demonstrate that our proposed contrastive divergence loss further improves the performance over current state-of-the-art approaches

Influence of edge crack on frequencies of thin plate in bending

This paper investigates the influence of crack location and crack length on changes in natural frequencies of bending thin plate. To perform this analysis, a computing program called CRACK-PLATE, using the finite element method based on the Ressner-Mindlin' theory of plate is developed. In order to achieve a high accuracy, an isoparametric element of Barsoum is combined with an 8-node quadrilateral isoparametric element. The numerical results show that the natural frequencies are very sensitive to the crack presence in the bending thin plate. This study is a basis for crack identification based on natural frequencies of plates