169 research outputs found

    APPLICATION OF PID METHOD TO CONTROL TRACTION ON THE VEHICLES THROUGH CONTROLLING THE BRAKE MOMENT AT THE TWO DRIVING WHEELS

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    A vehicle differential is a device that divides engine power between the two driving wheels and allows the wheels to rotate at different speeds when the vehicle moves on the road. The speed difference depends mainly on the grip between the wheels and the road surface. When the traction acting on both driving wheels is equal, the differential will distribute traction equally, helping the vehicle move stably on a straight road. However, if one of the two driving wheels rolls on a slippery road, the differential will distribute more engine power to this wheel. As a result, the vehicle’s motion is unstable, engine power is lost, the vehicle cannot move. To solve the problem, using a limited-slip differential, an active differential or a traction control system is considered an optimal solution. This study uses the brake moment acting on the skidding wheel to redistribute the engine power at the two driving wheels and uses the PID method for traction control at the drive wheels. Survey results show the effectiveness of the designed controller

    The Improvement Model of Navigational Safety for Inland Waterway Transport

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    This paper aims at evaluating navigational safety for inland waterway transport (IWT). In doing so, the literature and operational features of IWT were initially reviewed to figure out risk elements (REs) influencing the navigational safety for IWT. After that, a fuzzy Analytic Hierarchical Process (AHP) approach was adopted to estimate the weight for the likelihood and consequence measures of REs. Then, continuous risk matrix (RM) was introduced to identify REs\u27 risk level. Lastly, to test the proposed research model\u27s applicability, IWT operators across Vietnam were empirically surveyed. The empirical findings could be useful for IWT operators in launching managerial policies to boost their navigational safety. Furthermore, the proposed risk evaluation framework may serve as a methodological reference in relevant literature

    The Improvement Model of Navigational Safety for Inland Waterway Transport

    Get PDF
    This paper aims at evaluating navigational safety for inland waterway transport (IWT). In doing so, the literature and operational features of IWT were initially reviewed to figure out risk elements (REs) influencing the navigational safety for IWT. After that, a fuzzy Analytic Hierarchical Process (AHP) approach was adopted to estimate the weight for the likelihood and consequence measures of REs. Then, continuous risk matrix (RM) was introduced to identify REs\u27 risk level. Lastly, to test the proposed research model\u27s applicability, IWT operators across Vietnam were empirically surveyed. The empirical findings could be useful for IWT operators in launching managerial policies to boost their navigational safety. Furthermore, the proposed risk evaluation framework may serve as a methodological reference in relevant literature

    Energy Consumption Minimization for Autonomous Mobile Robot: A Convex Approximation Approach

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    In this paper, we consider a trajectory design problem of an autonomous mobile robot working in industrial environments. In particular, we formulate an optimization problem that jointly determines the trajectory of the robot and the time step duration to minimize the energy consumption without obstacle collisions. We consider both static and moving obstacles scenarios. The optimization problems are nonconvex, and the main contribution of this work proposing successive convex approximation (SCA) algorithms to solve the nonconvex problems with the presence of both static and moving obstacles. In particular, we first consider the optimization problem in the scenario with static obstacles and then consider the optimization problem in the scenario with static and moving obstacles. Then, we propose two SCA algorithms to solve the nonconvex optimization problems in both the scenarios. Simulation results clearly show that the proposed algorithms outperform the A* algorithm, in terms of energy consumption. This shows the effectiveness of the proposed algorithms

    An Efficient Method for Generating Synthetic Data for Low-Resource Machine Translation – An empirical study of Chinese, Japanese to Vietnamese Neural Machine Translation

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    Data sparsity is one of the challenges for low-resource language pairs in Neural Machine Translation (NMT). Previous works have presented different approaches for data augmentation, but they mostly require additional resources and obtain low-quality dummy data in the low-resource issue. This paper proposes a simple and effective novel for generating synthetic bilingual data without using external resources as in previous approaches. Moreover, some works recently have shown that multilingual translation or transfer learning can boost the translation quality in low-resource situations. However, for logographic languages such as Chinese or Japanese, this approach is still limited due to the differences in translation units in the vocabularies. Although Japanese texts contain Kanji characters that are derived from Chinese characters, and they are quite homologous in sharp and meaning, the word orders in the sentences of these languages have a big divergence. Our study will investigate these impacts in machine translation. In addition, a combined pre-trained model is also leveraged to demonstrate the efficacy of translation tasks in the more high-resource scenario. Our experiments present performance improvements up to +6.2 and +7.8 BLEU scores over bilingual baseline systems on two low-resource translation tasks from Chinese to Vietnamese and Japanese to Vietnamese

    Straightforward Procedure for Laboratory Production of DNA Ladder

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    DNA ladder is commonly used to determine the size of DNA fragments by electrophoresis in routine molecular biology laboratories. In this study, we report a new procedure to prepare a DNA ladder that consists of 10 fragments from 100 to 1000 bp. This protocol is a combination of routinely employed methods: cloning, PCR, and partial digestion with restriction enzymes. DNA fragments of 100 bp with unique restriction site at both ends were self-ligated to create a tandem repeat. Once being cloned, the tandem repeat was rapidly amplified by PCR and partially digested by restriction enzymes to produce a ladder containing multimers of the repeated DNA fragments. Our procedure for production of DNA ladder could be simple, time saving, and inexpensive in comparison with current ones widely used in most laboratories
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