276 research outputs found

    PSO based Hybrid PID-FLC Sugeno Control for Excitation System of Large Synchronous Motor

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    This paper proposes a hybrid control system integrating a PID controller and a fuzzy logic controller, using the particle swarm optimization (PSO) algorithm to optimize control parameters. The control object is an excitation system for a large synchronous motor, which is widely used in large power transmission systems. In practice, the change in load and excitation source can affect the operating mode of the motor. Therefore, a hybrid controller is designed to stabilize the power factor, resulting in better working performance. In the control algorithm, a PID controller is initially designed using PSO to optimize the control coefficients. The FLC-Sugeno control is then integrated with the PID, in which PSO is utilized to optimize membership functions. Numerical simulation results demonstrate the advantages of the proposed approach. Doi: 10.28991/ESJ-2022-06-02-01 Full Text: PD

    Academic Staffs’ Participation in University Governance Towards Autonomy: Practice at Two University Models in Vietnam

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    Vietnamese universities are now in a state of “diverse governing bodies” and the Ministry of Education and Training is responsible for their expertise. This model can cause overlapping or loosened management by many agencies simultaneously managing. Vietnamese universities need to promote autonomy and accountability in management. This study was conducted in 2018-2019 with 322 lecturers and educational managers working at two Vietnamese public universities governed by different autonomy policies. This research analyses the academic staff’ s participation in university governance toward autonomy. The research results show that (i) there is no difference between the two universities in the level of participation in governance activities; (ii) The academic staff’ s participation levels are positively correlated from low to moderate levels according to the effectiveness of participating in activities; (iii) The higher the participation level, the higher the scientific research results are for domestic publication. However, it is not a significant case for international publication

    Modeling of parallel power MOSFETs in steady-state

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    In high-power applications, multiple power MOSFETs are connected in parallel and treated as a single switch in order to handle much larger total currents. In this paper, a parallel power MOSFETs model from the turnoff state until they reach their steady state is introduced. The model represents the relationship between each power MOSFET's gate voltage and the current distribution among them. The study's key purpose is to use the model for dealing with the asymmetry in sharing current and power loss between these semiconductor devices during the steady state region.Comment: 10 pages, 7 figures, The 2023 INTERNATIONAL SYMPOSIUM ON ADVANCED ENGINEERING (ISAE2023

    Enantioselective separation of ofloxacin by ligand exchange chromatography

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    A ligand exchange HPLC method for enantioseparation of ofloxacin enantiomers was developed by a using C8 stationary phase. Chromatographic separation was performed on a Zorbax-300SB-C8 column eluted with the mobile phase consisting of 15 % methanol in water containing 10mM phenylalanin and 5 mM CuSO4 at flow rate of 0.8 mL/min. The method was simple, rapid and suitable for routine analytical studies of ofloxacin enantiomers

    A THEORETICAL STUDY ON CHEMICAL BONDING AND INFRARED SPECTRA OF SinM (M = Sc, Y; n = 1-10) CLUSTERS

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    In this paper, we applied the B3P86 method and DGDZVP basis set to investigate electronic properties and infrared (IR) spectra for SinM (M = Sc, Y; n = 1-10) clusters. The NBO analyses show that electron transfers from the dopant atoms to silicon frame of the SinM clusters. It is remarkable that the Si-M bond is mainly formed by the overlaps of the 3s-AOs and 3p-AOs of Si atoms, and 3d-AOs and 4s-AOs of Sc (or 4d-AOs and AO-5s of Y). The chemical bonds in the SiM and Si2M clusters are dominated by the covalent character including sigma and pi bonds. In addition, the analysis of the IR spectra suggests that the vibrational modes of SinM clusters are delocalized over the whole cluster. Moreover, the high-frequency and strong-intensity modes usually involve the vibrations of the dopant atoms. The results of this work provide fundamental information for experimental studies on transition-metal doped silicon clusters

    Semi-Supervised Semantic Segmentation using Redesigned Self-Training for White Blood Cells

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    Artificial Intelligence (AI) in healthcare, especially in white blood cell cancer diagnosis, is hindered by two primary challenges: the lack of large-scale labeled datasets for white blood cell (WBC) segmentation and outdated segmentation methods. These challenges inhibit the development of more accurate and modern techniques to diagnose cancer relating to white blood cells. To address the first challenge, a semi-supervised learning framework should be devised to efficiently capitalize on the scarcity of the dataset available. In this work, we address this issue by proposing a novel self-training pipeline with the incorporation of FixMatch. Self-training is a technique that utilizes the model trained on labeled data to generate pseudo-labels for the unlabeled data and then re-train on both of them. FixMatch is a consistency-regularization algorithm to enforce the model's robustness against variations in the input image. We discover that by incorporating FixMatch in the self-training pipeline, the performance improves in the majority of cases. Our performance achieved the best performance with the self-training scheme with consistency on DeepLab-V3 architecture and ResNet-50, reaching 90.69%, 87.37%, and 76.49% on Zheng 1, Zheng 2, and LISC datasets, respectively

    ẢNH HƯỞNG CỦA NƯỚC BIỂN DÂNG ĐẾN THỦY TRIỀU KHU VỰC BIỂN MIỀN TRUNG CỦA VIỆT NAM

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    The tide is one of the most important phenomena in the ocean. In the world as well as in Vietnam, the tide was studied very early and great achievements have been recorded. However, under the impact of climate change and sea level rise, the local - to - regional - scale changes will cause significant changes in the coastal system. This paper gives some results of research on the tidal changes in the central region of Vietnam by using the hydrodynamic model and data analysing model. The simulation results of the tide in the central coast of Vietnam show that the tide can change both in the amplitude and phase distribution of the tidal constituents as M2, S2, K1 and O1. Specifically, the results of the average values of M2 are 0.1 m and 10.20; for S2 are 0.12 m and 12.50; for K1 are 0.2 m and 17.20; for O1 are 0.21 m and 20.20. Some results of this study showed that the most important contribution to the change of the tide in the region is the change of topography and the submerged areas.Thủy triều là một trong những hiện tượng quan trọng nhất trong đại dương. Trên thế giới cũng như ở Việt Nam, thủy triều được nghiên cứu từ rất sớm và đã đạt được nhiều thành tựu to lớn. Tuy nhiên, dưới tác động của biến đổi khí hậu và nước biển dâng, các quá trình có quy mô khu vực mang tính chất địa phương sẽ gây ra những thay đổi quan trọng trong các hệ thống ven biển. Bài báo này đưa ra một số kết quả nghiên cứu sự biến đổi của thủy triều trong khu vực biển miền Trung của Việt Nam. Nghiên cứu sử dụng phương pháp mô hình và phân tích điều hòa. Các kết quả mô phỏng về thủy triều trong khu vực biển miền Trung của Việt Nam cho thấy rằng thủy triều có sự biến đổi cả về biên độ và pha của các phân triều chính như M2, S2, K1 và O1. Cụ thể, kết quả giá trị trung bình đối với M2 là 0,1 m và 10,20; đối với S2 là 0,12 m và 12,50; đối với K1 là 0,2 m và 17,20; đối với O1 là 0,21 m và 20,20. Một số kết quả nghiên cứu này đã cho thấy rằng những đóng góp quan trọng nhất vào sự thay đổi của thủy triều trong khu vực là sự thay đổi địa hình và diện tích của thủy vực
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