34 research outputs found

    Modified sunflower optimization for network reconfiguration and distributed generation placement

    Get PDF
    This paper proposed modified sunflower optimization (MSFO) for the combination of network reconfiguration and distributed generation placement problem (NR-DGP) to minimize power loss of the electric distribution system (EDS). Sunflower optimization (SFO) is inspired form the ideal of sunflower plant motion to get the sunlight and its reproduction. To enhance the performance of SFO, it is modified to MSFO wherein, the pollination and mortality techniques have been modified by using Levy distribution and mutation of the best solutions. The results are evaluated on two test systems. The efficiency of MSFO is compared with that of the original SFO and other algorithms in literature. The comparisons show that MSFO outperforms to SFO and other methods in obtained optimal solution. Furthermore, MSFO demonstrates the better statistical results than SFO. So, MSFO can be a powerful approach for the NR-DGP problem

    An Application of Modified T2FHC Algorithm in Two-Link Robot Controller

    Get PDF
    Parallel robotic systems have shown their advantages over the traditional serial robots such as high payload capacity, high speed, and high precision. Their applications are widespread from transportation to manufacturing fields. Therefore, most of the recent studies in parallel robots focus on finding the best method to improve the system accuracy. Enhancing this metric, however, is still the biggest challenge in controlling a parallel robot owing to the complex mathematical model of the system. In this paper, we present a novel solution to this problem with a Type 2 Fuzzy Coherent Controller Network (T2FHC), which is composed of a Type 2 Cerebellar Model Coupling Controller (CMAC) with its fast convergence ability and a Brain Emotional Learning Controller (BELC) using the Lyaponov-based weight updating rule. In addition, the T2FHC is combined with a surface generator to increase the system flexibility. To evaluate its applicability in real life, the proposed controller was tested on a Quanser 2-DOF robot system in three case studies: no load, 180 g load and 360 g load, respectively. The results showed that the proposed structure achieved superior performance compared to those of available algorithms such as CMAC and Novel Self-Organizing Fuzzy CMAC (NSOF CMAC). The Root Mean Square Error (RMSE) index of the system that was 2.20E-06 for angle A and 2.26E-06 for angle B and the tracking error that was -6.42E-04 for angle A and 2.27E-04 for angle B demonstrate the good stability and high accuracy of the proposed T2FHC. With this outstanding achievement, the proposed method is promising to be applied to many applications using nonlinear systems

    A Novel Self-organizing Fuzzy Cerebellar Model Articulation Controller Based Overlapping Gaussian Membership Function for Controlling Robotic System

    Get PDF
    This paper introduces an effective intelligent controller for robotic systems with uncertainties. The proposed method is a novel self-organizing fuzzy cerebellar model articulation controller (NSOFC) which is a combination of a cerebellar model articulation controller (CMAC) and sliding mode control (SMC). We also present a new Gaussian membership function (GMF) that is designed by the combination of the prior and current GMF for each layer of CMAC. In addition, the relevant data of the prior GMF is used to check tracking errors more accurately. The inputs of the proposed controller can be mixed simultaneously between the prior and current states according to the corresponding errors. Moreover, the controller uses a self-organizing approach which can increase or decrease the number of layers, therefore the structures of NSOFC can be adjusted automatically. The proposed method consists of a NSOFC controller and a compensation controller. The NSOFC controller is used to estimate the ideal controller, and the compensation controller is used to eliminate the approximated error. The online parameters tuning law of NSOFC is designed based on Lyapunov’s theory to ensure stability of the system. Finally, the experimental results of a 2 DOF robot arm are used to demonstrate the efficiency of the proposed controller

    Social Capital and Corporate Performance: Evidence from State Capital Enterprises in Vietnam

    Get PDF
    The research has been conducted to explore the combination of three intangible resources, including social capital, entrepreneurship, and resilience capability on the performance of State Capital Enterprises (SCEs) in Vietnam. Both qualitative and quantitative approaches are applied in the study. An in-depth interview of ten CEOs at SCEs in Vietnam was made to explore new indicators for the contextual latent variables in the research models. By employing the data from the authors’ survey of 568 SCEs in Vietnam in 2019, using Cronbach’s alpha, confrmatory factor analysis (CFA) and path analysis (SEM), the mechanism that social capital impacts on SCE performance has been analyzed. In addition to the direct role, social capital indirectly affects corporate performance through entrepreneurship and resilience capability. It was found that social capital has a larger impact on entrepreneurship than resilience capacity. However, the contribution of resilience capacity to the frm performance is much more than the entrepreneurship’s in Vietnamese context. This study enriches the theory by proposing a measurement scale of the contextual latent variables as a result of in-depth interviews with experts using a qualitative analysis technique. In addition, the path analysis fndings suggest practical implications for managers to effectively use their resources in SCEs

    Influence of Disulfide Bridge on the Structural Stability of Human Neuroglobin: A Molecular Dynamics Simulation Using Latest Data Entry

    Get PDF
    In this paper, we investigated the role of the disulfide bridge in the structural stability of wild-type human neuroglobin. The classical simulation of the neuroglobin without the disulfide bridge was performed for a long simulation run of 240~ns   using a new parameter set of Gromos96 force field and the latest data entry as the initial topologies. We used the analyzed data of original neuroglobin with the remained disulfide bridge to compare to the ones from this simulation. Our results showed that, the structure of neuroglobin was still very stable although the disulfide bridge was absent. There was only a few residues in B and C helices having a higher mobility. The most interesting result we obtained was that the increasing distance between the distal histidine and heme group could allow oxygen to bind more easily

    Robust Adaptive Cerebellar Model Articulation Controller for 1-DOF Nonlaminated Active Magnetic Bearings

    Get PDF
    This paper presents a robust adaptive cerebellar model articulation controller (RACMAC) for 1-DOF nonlaminated active magnetic bearings (AMBs) to achieve desired positions for the rotor using a robust sliding mode control based. The dynamic model of 1-DOF nonlaminated AMB is introduced in fractional order equations. However, it is challenging to design a controller based on the model\u27s parameters due to undefined components and external disturbances such as eddy current losses in the actuator, external disturbance, variant parameters of the model while operating. In order to tackle the problem, RACMAC, which has a cerebellar model to estimate nonlinear disturbances, is investigated to resolve this problem. Based on this estimation, a robust adaptive controller that approximates the ideal and compensation controllers is calculated. The online parameters of the neural network are adjusted using Lyapunov\u27s stability theory to ensure the stability of system. Simulation results are presented to demonstrate the effectiveness of the proposed controller.The simulation results indicate that the CMAC multiple nonlinear multiple estimators are close to the actual nonlinear disturbance value, and the effectiveness of the proposed RACMAC method compared with the FOPID and SMC controllers has been studied previously

    Effect of Plumbagin on growth inhibition and apoptosis of imatinib-resistant chronic myeloid leukemia

    Get PDF
    Development of a new inhibitor of BCR-ABL tyrosine kinase is necessary for the treatment of chronic myeloid leukemia (CML) because of increasing resistance and tolerance to Imatinid efforts. Herein, we reported Plumbagin can significantly inhibit the growth of CML. The results revealed that Plumbagin inhitbited TCCY and TCCY/T315I cells with IC50 values 3 ÎĽM and 2.1 ÎĽM, respectively. Plumbagin also showed anti-proliferative effects on both the wide type Ba/F3 and the BCR-ABL-transfected Ba/F3 cells with a range of IC50 from 3.2 to 3.8 ÎĽM. In addition, Plumbagin induced the apoptosis of CML cells. That would provide a new and potential drug as a chemotherapy medication in the treatment of Imatinid -resistant CML

    Immunohistochemical expression of anaplastic lymphoma kinase in neuroblastoma and its relations with some clinical and histopathological features

    Get PDF
    Background Anaplastic lymphoma kinase (ALK) mutations have been identified as a prominent cause of some familial and sporadic neuroblastoma (NB). ALK expression in NB and its relationship with clinical and histopathological features remains controversial. This study investigated ALK expression and its potential relations with these features in NB. Methods Ninety cases of NB at the Department of Pathology, University of Medicine and Pharmacy at Ho Chi Minh City, Viet Nam from 01/01/2018 to 12/31/2021, were immunohistochemically stained with ALK (D5F3) antibody. The ALK expression and its relations with some clinical and histopathological features were investigated. Results The rate of ALK expression in NB was 91.1%. High ALK expression (over 50% of tumor cells were positive with moderate-strong intensity) accounted for 65.6%, and low ALK expression accounted for 34.4%. All the MYCN-amplified NB patients had ALK immunohistochemistry positivity, most cases had high ALK protein expression. The undifferentiated subtype of NB had a lower ALK-positive rate than the poorly differentiated and differentiated subtype. The percentages of ALK positivity were significantly higher in more differentiated histological types of NB (p = .024). There was no relation between ALK expression and: age group, sex, primary tumor location, tumor stage, MYCN status, clinical risk, Mitotic-Karyorrhectic Index, prognostic group, necrosis, and calcification. Conclusions ALK was highly expressed in NB. ALK expression was not related to several clinical and histopathological features. More studies are needed to elucidate the association between ALK expression and ALK gene status and to investigate disease progression, especially the oncogenesis of ALK-positive NB

    CSA: Thực hành nông nghiệp thông minh với khí hậu ở Việt Nam

    No full text
    During the last five years, Vietnam has been one of the countries most affected by climate change. Severe typhoons, flooding, cold spells, salinity intrusion, and drought have affected agriculture production across the country, from upland to lowland regions. Fortunately for Vietnam, continuous work in developing climate-smart agriculture has been occurring in research organizations and among innovative farmers and entrepreneurs. Application of various CSA practices and technologies to adapt to the impact of climate change in agriculture production have been expanding. However, there is a need to accelerate the scaling process of these practices and technologies in order to ensure growth of agriculture production and food security, increase income of farmers, make farming climate resilient, and contribute to global climate change mitigation. This book aims to provide basic information to researchers, managers, and technicians and extentionists at different levels on what CSA practices and technologies can be up scaled in different locations in Vietnam
    corecore