Current Issue : October - December Volume : 2017 Issue Number : 4 Articles : 5 Articles
In recent years, because of the development of marine military science technology,\nthere is a growing interest in the unmanned systems throughout the\nworld. Also, the demand of Unmanned Surface Vehicles (USVs) which can be\nautonomously operated without the operator intervention is increasing dramatically.\nThe growing interests lie in the facts that those USVs can be manufactured\nat much lower costs, and can be operated without the human fatigue,\nwhile can be sent to the hostile or quite dangerous areas that are inherently\nunhealthy for human operators. The utilization and the deployment of such\nvessels will continue to grow in the future. In this paper, along with the technological\ndevelopment of unmanned surface vehicles, we investigate and analyze\nthe cases of already developed platforms and identify the trends of the\ntechnological advances. Additionally, we suggest the future directions of development....
Designers and artists often require reference images at authoring time. The emergence\nof computer technology has provided new conditions and possibilities for artistic creation and\nresearch. It has also expanded the forms of artistic expression and attracted many artists, designers\nand computer experts to explore different artistic directions and collaborate with one another. In this\npaper, we present an efficient k-means-based method to segment the colors of an original picture to\nanalyze the composition ratio of the color information and calculate individual color areas that are\nassociated with their sizes. This information is transformed into regular geometries to reconstruct the\ncolors of the picture to generate abstract images. Furthermore, we designed an application system\nusing the proposed method and generated many works; some artists and designers have used it as\nan auxiliary tool for art and design creation. The experimental results of datasets demonstrate the\neffectiveness of our method and can give us inspiration for our work....
Air gap eccentricity faults in five-phase ferrite-assisted synchronous reluctance motors\n(fPMa-SynRMs) tend to distort the magnetic flux in the air gap, which in turn affects the spectral\ncontent of both the stator currents and the ZSVC (zero-sequence voltage component). However,\nthere is a lack of research dealing with the topic of fault diagnosis in multi-phase PMa-SynRMs, and in\nparticular, those focused on detecting eccentricity faults. An analysis of the spectral components\nof the line currents and the ZSVC allows the development of fault diagnosis algorithms to detect\neccentricity faults. The effect of the operating conditions is also analyzed, since this paper shows that\nit has a non-negligible impact on the effectivity and sensitivity of the diagnosis based on an analysis of\nthe stator currents and the ZSVC. To this end, different operating conditions are analyzed. The paper\nalso evaluates the influence of the operating conditions on the harmonic content of the line currents\nand the ZSVC, and determines the most suitable operating conditions to enhance the sensitivity of\nthe analyzed methods. Finally, fault indicators employed to detect eccentricity faults, which are based\non the spectral content of the stator currents and the ZSVC, are derived and their performance is\nassessed. The approach presented in this work may be useful for developing fault diagnosis strategies\nbased on the acquisition and subsequent analysis and interpretation of the spectral content of the line\ncurrents and the ZSVC....
For resolving deficiencies of conventional tension measurement methods, this paper\nproposes a novel eddy current sensor with a single-coil structure based on the inverse magnetostrictive\neffect. An inductorââ?¬â??resistorââ?¬â??capacitor (LRC) model of eddy current sensor, which considers more\nparameters than the traditional inductorââ?¬â??resistor (LR) model, was established. The eddy current\nsensor was operated by a swept frequency signal that ranged from 0.1 MHz to 1.6 MHz, encompassing\nthe sensor resonant frequency. At the resonant frequency, the data of impedance magnitude and phase\nwere extracted and linear relations between the impedance parameters and the external tension were\nascertained. The experimental results show that the resonant frequency and impedance magnitude of\neddy current sensor will decrease linearly with the increase of the external tension, which is consistent\nwith the theoretical model. In addition, to improve sensor performance, the sleeve structure was\ndesigned to reduce the loss of magnetic field. Both finite element simulations and experimental results\ndemonstrate that the sleeve structure provides a higher permeability path to the magnetic field lines\nthan the non-sleeve structure and effectively improves sensor sensitivity and correlation coefficient....
In this paper, a photosensor-based latency measurement system for head-mounted displays\n(HMDs) is proposed. The motion-to-photon latency is the greatest reason for motion sickness and\ndizziness felt by users when wearing an HMD system. Therefore, a measurement system is required\nto accurately measure and analyze the latency to reduce these problems. The existing measurement\nsystem does not consider the actual physical movement in humans, and its accuracy is also very\nlow. However, the proposed system considers the physical head movement and is highly accurate.\nSpecifically, it consists of a head position model-based rotary platform, pixel luminance change\ndetector, and signal analysis and calculation modules. Using these modules, the proposed system\ncan exactly measure the latency, which is the time difference between the physical movement for a\nuser and the luminance change of an output image. In the experiment using a commercial HMD,\nthe latency was measured to be up to 47.05 ms. In addition, the measured latency increased up to\n381.17 ms when increasing the rendering workload in the HMD....
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