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Results in Journal IEEE Access: 39,249

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Hao Zhang, Dianjun Zhang, Anmin Zhang
IEEE Access pp 1-1; doi:10.1109/access.2020.3024020

Abstract:
The Tianjin port plays a relevant role in driving both ship navigation and the weather and climate of the area. To better understand the underlying peculiarities of this area, several in-service coastal ocean system and facilities have been constructed, at present, the whole coastal ocean systems at Tianjin port have been improved, however, they cannot meet the safety requirements of traffic management and navigational safety. Marine buoys have the unreplaceable advantages of long-term, real-time, reliable capabilities and trivial environmental restrictions to monitor the marine dynamics. Here an innovative multifunctional buoy prototype is proposed to continuously measure meteorological and oceanographic parameters at a high spatial and temporal resolution, which can ensure navigation safety at Tianjin Port. Solar panels and battery module are personalized to ensure electric supply to the buoy system. An independent ARM (Advanced RISC Machine)-based module is affiliated to maintain the stability of the data acquisition and communication module. Buoy platform based on Beidou difference is proved to be an effective approach for the tide measurement. Additionally, a web-designed software for data acquisition is integrated for the visualization purpose. Finally, in-field recording test at Tianjin port will be performed to verify effectiveness of our system on monitoring environment dynamics. It turns out that our buoy prototype functions as a reliable and energy favorable electrical device and shed light on the development of effective measurement instruments working under unpredictable and harsh marine environment.
Enqi Yan, Xiye Guo, Jun Yang, Zhijun Meng, Kai Liu, Xiaoyu Li, Guokai Chen
IEEE Access pp 1-1; doi:10.1109/access.2020.3024031

Abstract:
In the positioning and navigation field, it is essential to use the direction-finding system to obtain the signal direction of arrival (DOA) and target position. The amplitude comparison-based monopulse (ACM) DOA algorithm performs a few calculations, has a simple system structure, and is widely used. The traditional ACM DOA algorithm uses the first-order Taylor expansion to introduce the nonlinear errors, and the angle measurement range is limited. In response to this problem, this study establishes a neural network model for error compensation, and it optimizes the traditional algorithm to obtain a better angle estimation performance. In order to perform an experiment with the proposed algorithm, a novel experimental device was designed. Two measurements at different angles were obtained by rotating the antenna. The ACM angle estimation used only one directional antenna. The results verified the optimization algorithm. The experimental results demonstrated that in comparison with the traditional first-order and the improved third-order Taylor expansion ACM DOA algorithm, the mean absolute error of this method reduced by 81.62% and 72.62%, respectively.
Ki-Hoon Kim, Dong-Kyun Woo
IEEE Access pp 1-1; doi:10.1109/access.2020.3023907

Abstract:
This paper considers a linear tubular permanent magnet motor (LTPMM) for an active suspension system. The LTPMM has an end effect due to its structure. This can be an important factor for analysis and design of the LTPMM because it distorts the air-gap magnetic flux distribution. The field reconstruction method (FRM) was developed for an effective evaluation of the magnetic field in the electric machine. It can reduce the computation time using the basis-function which reconstructs the air-gap magnetic flux distribution with a static finite element analysis. In this paper, we adopted the FRM to evaluate the LTPMM. However, the FRM has been applied only to the rotating machines and does not take into account the distortion of the magnetic flux distribution in the LTPMM. To deal with this problem, we proposed an enhanced FRM with new basis-function. The proposed method is verified by comparing between experiment result, conventional and enhanced FRM.
Xiaoyan Qian, Yun Yang, Chendan Li, Siew-Chong Tan
IEEE Access pp 1-1; doi:10.1109/access.2020.3024112

Abstract:
Virtual resistance-based droop control is widely adopted as secondary-layer control for grid-connected converters in DC microgrids. This paper presents an alternative usage of the virtual resistances to minimize the total operating cost of DC microgrids under real-time pricing. The total operating cost covers the running cost of utility grids, renewable energy sources (RES), energy storage systems (ESS), fuel cells, and power loss on the distribution lines. An adaptive Differential Evolution (ADE) algorithm is adopted in this paper to optimize the virtual resistances of the droop control for the grid-connected converters of dispatchable units, such that the power flow can be regulated. The performances of the proposed strategy are evaluated by the case studies of a 12-bus 380 V DC microgrid using Matlab and a 32-bus 380 V DC microgrid using a Real-Time Digital Simulator (RTDS). Both results validate that the ADE can significantly reduce the operating cost of DC microgrids and outperform the conventional Genetic Algorithm (GA) in terms of cost saving. Comparisons among the microgrids with different numbers of dispatchable units reveal that the cost saving is more prominent when the expansion of dispatchable units.
Henrique P. Correa, Flavio H. T. Vieira
IEEE Access pp 1-1; doi:10.1109/access.2020.3023675

Abstract:
A renewed interest in phase frame analysis of distribution systems has surfaced in recent literature due to rapid expansion of grid-integrated distributed generation and non-linear loads, whose grid imbalance-increasing effects require more detailed analysis and modeling of distribution systems for their proper assessment. In this paper, under motivation of such recent usage of phase frame components, we propose analytical equations for N-phase neutral-equipped line admittance matrix under transposition assumption. By using the proposed equations, we evaluate precision losses caused by using the transposition assumption for modeling three-phase four-wire distribution lines. Moreover, differently from previous works, we validate the transposition assumption and the admittance matrix values obtained for various combinations of cable type and line geometry. A relevant reason for analyzing transposition assumption in more detail is the fact that it may be useful in distribution system computations, due to its advantageous decoupling of symmetrical components. In this sense, the present work provides additional discussion and illustrative evaluations of the line transposition assumption, which may be useful for analyzing its applicability under different circumstances.
Arsalan Arif, Noman Baloch, Muhammad Ayub, Byung-Il Kwon
IEEE Access pp 1-1; doi:10.1109/access.2020.3023763

Abstract:
This paper proposes two permanent magnet vernier machines (PMVM) operation modes, for wide-speed and high efficiency operation. In mode-1, the machine operates as a conventional PMVM with a wye connected stator winding mode. In mode-2, the machine stator winding is switched to a wye-delta winding mode. Contrary to the existing dual-inverter PMVM topology with two additional bidirectional thyristor switches, the proposed topology utilizes a single inverter with six additional bidirectional thyristor switches to change mode. A theoretical discussion of the proposed idea is further verified via finite element analysis (FEA) simulations. The basic electromagnetic characteristics, such as the flux linkage, back electromotive force, torque, and phase voltages of the machine are investigated using wye and wye-delta stator winding configurations, and subsequently, compared with the existing topology that used a dual-inverter PMVM. The FEA results show that the proposed PMVM has low over-all losses, consequently resulting in improved efficiency compared to the existing topology. The speed increases by almost 9 times using the proposed single-inverter PMVM. Transient analysis using FEA is also conducted in this paper.
Flavio S. Bizarrias, Luciano F. Da Silva, Renato Penha, Rosaria F. S. M. Russo
IEEE Access pp 1-1; doi:10.1109/access.2020.3023897

Abstract:
In recent decades, project management has become more permeable to influences from other areas of knowledge, such as marketing. This influence led to project-based companies becoming market-oriented in their projects to achieve more success. However, the convergence of project management and marketing is still controversial. In this context, this study aims to assess the relationship between the vision of marketing, through conscious and unconscious processes, and its influence on the success of projects. Conscious processes deal with controlled and deliberate cognitive evaluations of anything, while unconscious processes are those that occur without one’s control and awareness. These mechanisms occur in parallel and influence our beliefs and behavior. Forty-five professionals working on projects participated in the survey. We collected the data through a structured questionnaire, to the conscious process, and a computerized task for the unconscious data using an instrument called Project Marketing Implicit Association Test. Thus, the study presented analyzes on how project managers conceive their conscious and unconscious perception of how marketing and project management can reconcile into a theoretical and practical convergent concept. The results provide evidence of a positive and significant influence of conscious and unconscious processes on project success. It was also revealed that these processes act independently, enhancing the project’s success.
Thau-Soon Khoo, Mohammad Babrdel Bonad, Voon-Hee Wong, Yong-Haur Tay, Madhavan Balan Nair
IEEE Access pp 1-1; doi:10.1109/access.2020.3023741

Abstract:
Developing an algorithm that can solve the vehicle routing problem with time windows (VRPTW) and create near-optimal solutions with the least difference in magnitude is a challenging task. This task is evident from the fact that when an algorithm runs multiple times based on a given instance, the generated solutions deviate from each other and may not near-optimal. For this reason, an algorithm that can solve these problems is effective and highly sought after. This paper proposes a novel systematic framework using a two-phase distributed ruin-and-recreate genetic algorithm (RRGA). The two-phase consists of the RRGA phase and ruin-and-recreate (RR) phase, which is designed to run in the distributed computing environment that leveraging these networked resources. This combination of algorithms harnesses the strength of the search diversification and intensification, thereby producing very high-quality solutions. Experiments with Solomon’s benchmark show the RRGA can produce results superior to the recently published hybrid algorithms, best-known solutions, and nine leading hybrid algorithms.
Baik-Kee Song, Dae-Kee Kim, Sung-Il Kim, Hyun-Jin Park, Geun-Ho Lee, Myung-Seop Lim
IEEE Access pp 1-1; doi:10.1109/access.2020.3023767

Abstract:
The performance of motors can vary considerably, depending not only on the design but also the manufacturing process. In particular, for motors used in systems wherein vibration and noise are important, the characteristics of the motors change according to the manufacturing method; hence, it is essential to study the effect of the manufacturing process on the characteristics of motors. In this study, motors with a connected core and segmented core are compared and analyzed; particularly, the motors are intended for use in a brake system. The general strengths and weaknesses of each core type are determined, and the electrical and mechanical properties of the motors are analyzed through finite element analysis (FEA). The motors are applied to an integrated brake system that does not employ a vacuum booster, and motors with each type of core are fabricated and tested to verify their characteristics. Finally, the analysis results obtained using FEA and the test results are compared and analyzed to evaluate the validity of this study.
Luis F. Guerrero-Vasquez, Vladimir E. Robles-Bykbaev, Martin Lopez-Nores, Jack F. Bravo-Torres, Henry J. Jara-Quito, Manuel A. Tapia-Vintimilla, Jose J. Pazos-Arias, Alberto Gil-Solla
IEEE Access pp 1-1; doi:10.1109/access.2020.3023737

Abstract:
Avatars have been found to be useful tools to overcome communication barriers in people affected by Autistic Spectrum Disorders (ASD) and to help them understand and express emotions. However, it has been shown that the success of the interactions is highly dependent on the subject’s identification with the avatar. In this study, we assess the variables that may influence that perception in children under 10, in the context of the largely multi-ethnic Ecuadorean society. The results reveal that, unlike previous studies showed for young adults, the ethnic traits displayed by the avatars are not a critical factor, as the the quality of the interactions was more influenced by the perception of the avatars’ appearance, their similarity with the kids’ peers and, above all, the ability of the human model who controls the avatar to use a pleasant voice, to succeed in making his/her questions and responses fully understood, and to master the non-verbal communication transmitted through gestures and voice.
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