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Fault Identification and Health Monitoring of Gas Turbine Engines Using Hybrid Machine Learning-based Strategies

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风机技术 2022年第1期64卷 71-80页

作者： Yan-yan Shen Khashayar Khorasani Department of Electrical and Computer Engineering Concordia UniversityMontrealCanada.

Ahealth monitoring scheme is developed in this work by using hybrid machine learning strategies to iden-tify the fault severity and assess the health status of the aircraft gas turbine engine that is subject to component degrada-tions that are caused by fouling and *** proposed hybrid framework involves integrating both supervised recur-rent neural networks and unsupervised self-organizing maps methodologies,where the former is developed to extract ef-fective features that can be associated with the engine health condition and the latter is constructed for fault severity modeling and tracking of each considered degradation *** of our proposed methodology are that it ac-complishes fault identification and health monitoring objectives by only discovering inherent health information that are available in the system I/O data at each operating *** effectiveness of our approach is validated and justified with engine data under various degradation modes in compressors and turbines.

关键词： Gas Turbine Engines Health Monitoring Fault Identification Self-organizing Maps Machine Learn-ing Recurrent Neural Networks

Design of Hard Compaction Rollers for Automated Fiber Placement on Complex Mandrel Geometries

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Journal of Mechanics Engineering and Automation 2018年第6期8卷 259-263页

作者： Tom T. Zacchia Farjad Shadmehri Jeffrey Fortin-Simpson Suong V. Hoa concordia Center for Composites (CONCOM) Department of Mechanical Industrial and Aerospace Engineering Concordia University Montreal H3G1M8 Canada

This paper presents a methodology for designing hard compaction rollers for an AFP(automated fiber placement)head with a hot gas torch heating system for laying thermoplastic CFRP(carbon fiber reinforced plastic)*** manufacturing defects and alternative designs are reviewed to highlight the importance of AFP compaction roller conformity and surface *** formulation of a general parametric description of the design challenge is derived and adequately addresses the problem on a tow-to-tow basis.

关键词： AFP CFRP compaction roller

3-D Modelling of the Confederation Bridge Using Data of Full Scale Tests

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Open Journal of Civil Engineering 2013年第3期3卷 18-25页

作者： Lan Lin Department of Building Civil and Environmental Engineering Concordia University Montreal Canada

Long-span bridges are special structures that require advanced analysis techniques to examine their performance. This paper presents a procedure developed to model the Confederation Bridge using 3-D beam elements. The model was validated using the data collected before the opening of the bridge to the public. The bridge was instrumented to conduct fullscale static and dynamic tests. The static tests were to measure the deflection of the bridge pier while the dynamic tests to measure the free vibrations of the pier due to a sudden release of the static load. Confederation Bridge is one of the longest reinforced concrete bridges in the world. It connects the province of Prince Edward Island and the province of New Brunswick in Canada. Due to its strategic location and vital role as a transportation link between these two provinces, it was designed using higher safety factors than those for typical highway bridges. After validating the present numerical model, a procedure was developed to evaluate the performance of similar bridges subjected to traffic and seismic loads. It is of interest to note that the foundation stiffness and the modulus of elasticity of the concrete have significant effects on the structural responses of the Confederation Bridge.

关键词： 3-D Numerical Modeling Finite Element Technique Static Tests Dynamic Tests Acceleration Time History Fourier Analysis Full Scale Test Seismic Evaluation Confederation Bridge

A spatial geostatistical analysis of impact of land use development on groundwater resources in the Sangong Oasis Region using remote sensing imagery and data

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Journal of Arid Land 2009年第1期1卷 1-8页

作者： Chen, Xi Yan, JinFeng Chen, Zhi Luo, GePing Song, Qing Xu, WenQiang Chinese Acad Sci Key Lab Oasis Ecol & Desert Environm Urumqi 830011 Peoples R China Chinese Acad Sci Xinjiang Inst Ecol & Geog Urumqi 830011 Peoples R China Qindao univ Sci & Technol Qingdao 266071 Peoples R China concordia univ Dept Bldg Civil & Environm Engn Montreal PQ Canada

In this study, the relationship between land use and cover change (LUCC) and variation of groundwater level and quality in the Sangong Oasis Region was investigated using a spatial geostatistical approach. Specifically, interactions among groundwater, surface water, and LUCC were analyzed through the utilization of geographical information system (GIS), remote sensing (RS) Imagery processing, and geostatistics. Study outputs indicated that recharging into the groundwater did not change significantly during the period from 1978 to 1998. However, both LUCC and groundwater level changed substantially in the Sangong Oasis Region, and their variations were closely correlated to each other spatially and temporally over the past two decades. It confirmed that urbanization process and increased industrial activities were the direct reasons of groundwater table descending and the deterioration of water quality. The results of this research provided a scientific basis for understanding sustainability-related problems and solution options in the oasis areas of western China.

关键词： spatial analysis remote sensing LUCC groundwater Sangong Oasis Region

An Interdisciplinary Challenge： Method Triangulation in the Field of Brain Development and Motivation

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Psychology Research 2012年第11期2卷 627-636页

作者： Diana Raufelder Danilo Jagenow Frances Hoferichter R. Poppy Wilkinson Frances HoferichterFreie universitat Berlin Germany concordia university Montreal Canada

Adaptive Fault Compensation for Aircraft Flight Systems with Actuator Faults

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Adaptive Fault Compensation for Aircraft Flight Systems with...

Some Explorations on Two Conjectures About Rademacher Sequences

第25届中国控制与决策会议

作者： Yuying Guo Youmin Zhang Bin Jiang School of Information Engineering Southwest University of Science and Technology Dept. of Mechanical and Industrial Engineering Concordia University College of Automation Engineering Nanjing University of Aeronautics and Astronautics

ISBN: (纸本)9781467355339

In this paper, an adaptive fault compensation scheme is investigated for aircraft flight systems in the presence of non-measurable rate on the actuator second-order dynamics. The proposed fault compensation scheme is a combination between multiple model and adaptive reconfiguration control. By means of the designed method, the system output can track that of reference model asymptotically, and desired performance of the developed scheme is demonstrated by simulation studies on the lateral dynamic model of a Boeing 747 airplane.

关键词： Actuator Fault Multiple Model Fault Compensation Flight Control System

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Acta Mathematicae Applicatae Sinica 2021年第1期37卷 1-16页

作者： Ze-chun HU Guo-lie LAN Wei SUN College of Mathematics Sichuan UniversityChengdu 610065China School of Economics and Statistics Guangzhou UniversityGuangzhou 510006China Department of Mathematics and Statistics Concordia UniversityMontreal H3G 1M8Canada

In this paper,we explore two conjectures about Rademacher ***(εi)be a Rademacher sequence,i.e.,a sequence of independent{-1,1}-valued symmetric random *** Sn=aiε1+…+anεn for a=(a1,…,an)∈*** first *** says that P(|Sn|≤‖a‖)>1/2 for all a∈Rn and n∈*** second conjecture says that P(|Sn|>‖a‖)≥7/32 for all a∈Rn and n∈*** the first conjecture,we present several new equivalent *** include a topological view,a combinatorial version and a strengthened version of the *** the second conjecture,we prove that it holds true when n<7.

关键词： Rademacher sequence Tomaszewaki’s constant Hitczenko and Kwapien’s constant

Interactive effects of reproductive assets and ambient predation risk on the threat-sensitive decisions of Trinidadian guppies

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Current Zoology 2016年第3期62卷 221-226页

作者： Jemma KATWAROO-ANDERSEN Chris K. ELVIDGE Indar RAMNARINE Grant E. BROWN Department of Biology Concordia University 7141 Sherbrooke St. West Montreal QC H4B 1R6 Canada Department of Life Sciences University of the West Indies St. Augustine Trinidad and Tobago

Threat-sensitive behavioral trade-offs allow prey animals to balance the conflicting demands of successful predator detection and avoidance and a suite of fitness-related activities such as forag- ing, mating, and territorial defense. Here, we test the hypothesis that background predation level and reproductive status interact to determine the form and intensity of threat-sensitive behavioral decisions of wild-caught female Trinidadian guppies Poecilia reticulata. Gravid and nongravid gup- pies collected from high- and low-predation pressure populations were exposed to serial dilutions of conspecific chemical alarm cues. Our results demonstrate that there was ＇no effect of reproduct- ive status on the response of females originating from a low-predation population, with both gravid and nongravid guppies exhibiting strong anti-predator responses to the lowest concentration of alarm cues tested. Increasing cue concentrations did not result in increases in response intensity. Conversely, we found a significant effect of reproductive status among guppies from a high- predation population. Nongravid females from the high-predation population exhibited a strong graded （proportional） response to increasing concentrations of alarm cue. Gravid females from the same high-predation population, however, shifted to a nongraded response. Together, these re- sults demonstrate that accrued reproductive assets influence the threat-sensitive behavioral deci- sions of prey, but only under conditions of high-ambient predation risk.

关键词： asset protection antipredator behavior fitness trade-offs ecological uncertainty chemical alarm cues.

挥发性有机化合物对室内空气品质影响研究进展

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暖通空调 2001年第6期31卷 25-31页

作者：张国强宋春玲陈建隆 F.哈吉格特湖南大学加拿大concordia大学

系统回顾了近年来一些国家对室内空气环境中挥发性有机化合物 (VOC)研究的各个方面 ,包括VOC研究在室内空气品质研究中的地位 ,建筑物内VOC对人体健康的影响 ,VOC研究的实验方法、理论方法及主要研究结论 ,各国政府、学术团体采取的行... 详细信息

系统回顾了近年来一些国家对室内空气环境中挥发性有机化合物 (VOC)研究的各个方面 ,包括VOC研究在室内空气品质研究中的地位 ,建筑物内VOC对人体健康的影响 ,VOC研究的实验方法、理论方法及主要研究结论 ,各国政府、学术团体采取的行动等。得出结论 :与建筑科学、环境科学及人体健康相关的工作人员 ,如居住者、建筑业主、建筑科学家、环境科学家、心理学家和生理学家、建筑师与暖通空调设计人员、建筑和装饰材料生产商、供应商 ,都应重视VOC问题。

关键词：挥发性有机物室内空气品质人体健康