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101.
Abdelmoty M. Ahmed Reda Abo Alez Gamal Tharwat Muhammad Taha B. Belgacem Ahmad M. J. Al Moustafa 《成像科学杂志》2020,68(1):11-23
ABSTRACTArabic sign language (ArSL) is method of communication between deaf communities in Arab countries; therefore, the development of systemsthat can recognize the gestures provides a means for the Deaf to easily integrate into society. In this research we implemented a computational structurefor an intelligent interpreter that automatically recognizes the isolated dynamic gestures. The proposed system recognizes and translates gesturesperformed with one or both hands. It comprises five subsystems, building dataset, video processing, feature extraction, mapping between ArSL and Arabictext, and text generation. To apply the system, 100-signs of ArSL was used, which was applied on 1500 video files. It's were divided into five classes:alphabet, numbers, "prepositions, pronouns and question words", Arabic life expressions, and "nouns and verbs". The evaluation indicated that thesystem automatically recognizes and translates isolated dynamic ArSL gestures by highly accurate manner. The results showed that the system accuracy is 95.8%. 相似文献
102.
为增加风电场总输出功率,基于大涡模拟(Large Eddy Simulation,LES)方法,采用致动线(Actuator Line,AL)技术,通过swak4Foam产生指数率风剪切,利用OpenFOAM对两台串列布置的5 MW风力机风电场进行不同叶轮俯仰数值模拟,对比各工况下风电场总输出功率,并结合流场分布云图分析总输出功率存在差别的内在原因。结果表明:风电场上游风力机尾迹会严重减弱下游风力机性能;俯仰策略可有效提升风电场总输出功率;俯仰角从0°增大/减小到±35°过程中,呈现出上游风力机功率先增后减、下游风力机功率持续增加的规律,风电场总输出功率升至极大值后开始下降;正俯仰角时风电场总输出功率较负俯仰角时的总输出功率更高。 相似文献
103.
目的研究复杂系统设计过程中设计师的设计认知和设计创新行为。方法通过国内外相关文献的研究和分析,总结归纳复杂系统设计问题界定和解决方案构思的认知过程、复杂系统创新设计构思的生成机制、复杂系统的创新设计策略,分析复杂系统设计认知和创新研究领域将发生的变革和未来发展的趋势。结论系统探讨了复杂系统设计认知与创新过程中的设计问题界定和解决方案构思的联合演化机制、给定和自发性解决方案示例,给设计师带来的认知固化和类比推理创新启发作用、结构化和机会主义的创新设计策略,发现当下的复杂系统创新设计理论和实践研究,还需要进一步开展跨学科知识融合激励的复杂系统创新设计研究,与此同时,加强关于设计师主观认知不确定性的定量建模研究,从而更好、更有针对性地探究复杂系统创新设计中认知过程的自然本质。 相似文献
104.
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107.
J.G. Grüne D. Knoop T. Domagala A. von Hehl 《Materialwissenschaft und Werkstofftechnik》2021,52(1):8-18
Laser beam melting (LBM) of aluminum alloys is gaining a wide popularity in different industrial applications as an alternative technology for the production of individual and complex parts. A long build time and the high amount of experimental work for optimizing or finding new process parameters are two of the current challenges for reaching an industrial maturity. This paper proposes an efficient way to determine new process parameters for aluminum alloy aluminum-silicon10-magnesium with highest build-up rates by using a 3D finite element model on the mesoscopic level. High laser power in combination with the hull-core build strategy was used to increase the build-up rate without impairing the part accuracy. The influences of high laser power, laser diameter and scan speed on the melt pool were studied by using a thermal simulation of single laser tracks. Based on the simulation results the process window could be derived and was tested on a laser beam melting (LBM) system. The achieved reduction of the build time of up to 31 % without loss in part accuracy proved the novel approach for the prediction of the required process window as an efficient method to reduce costly and time-consuming experimental work. 相似文献
108.
Since researchers began studying the mechanism of flavonoids’ anticancer activity, little attention has been focused on the modulation of redox state in cells as a potential chemotherapeutic strategy. However, recent studies have begun identifying that the anticancer effect of flavonoids occurs both in their antioxidative activity which scavenges ROS and their prooxidative activity which generates ROS. Against this backdrop, this study attempts to achieve a comprehensive analysis of the individual and separate study findings regarding flavonoids’ modulation of redox state in cancer cells. It focuses on the mechanism behind the anticancer effect, and mostly on the modulation of redox potential by flavonoids such as quercetin, hesperetin, apigenin, genistein, epigallocatechin-3-gallate (EGCG), luteolin and kaempferol in both in vitro and animal models. In addition, the clinical applications of and bioavailability of flavonoids were reviewed to help build a treatment strategy based on flavonoids’ prooxidative potential. 相似文献
109.
Muhammad Sanaullah Muhammad Kashif Babar Ahmad Tauqeer Safdar Mehdi Hassan Mohd Hilmi Hasan Amir Haider 《计算机、材料和连续体(英文)》2022,72(2):2501-2519
Communication is a basic need of every human being to exchange thoughts and interact with the society. Acute peoples usually confab through different spoken languages, whereas deaf people cannot do so. Therefore, the Sign Language (SL) is the communication medium of such people for their conversation and interaction with the society. The SL is expressed in terms of specific gesture for every word and a gesture is consisted in a sequence of performed signs. The acute people normally observe these signs to understand the difference between single and multiple gestures for singular and plural words respectively. The signs for singular words such as I, eat, drink, home are unalike the plural words as school, cars, players. A special training is required to gain the sufficient knowledge and practice so that people can differentiate and understand every gesture/sign appropriately. Innumerable researches have been performed to articulate the computer-based solution to understand the single gesture with the help of a single hand enumeration. The complete understanding of such communications are possible only with the help of this differentiation of gestures in computer-based solution of SL to cope with the real world environment. Hence, there is still a demand for specific environment to automate such a communication solution to interact with such type of special people. This research focuses on facilitating the deaf community by capturing the gestures in video format and then mapping and differentiating as single or multiple gestures used in words. Finally, these are converted into the respective words/sentences within a reasonable time. This provide a real time solution for the deaf people to communicate and interact with the society. 相似文献
110.