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Parametric Structural Optimization of 2D Complex Shape Based on Isogeometric Analysis

Computer Modeling in Engineering & sciences 2020年第7期124卷 203-225页

作者： Long Chen Li Xu Kai Wang Baotong Li Jun Hong School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai200093China Key Laboratory of Education Ministry for Modern Design&Rotor-Bearing System Xi’an Jiaotong UniversityXi’an710049China

The geometric model and the analysis model can be unified together through the isogeometric analysis method,which has potential to achieve seamless integration of CAD and *** design is a mainstream and successful method in CAD *** method is not continued in simulation and optimization stage because of the model conversion in conventional optimization method based on the finite element *** integration of the parametric modeling and the structural optimization by using isogeometric analysis is a natural and interesting *** paper proposed a method to realize a structural optimization of parametric complex shapes by using isogeometric *** the given feature curves and the constraints,a feature frame model is *** on the feature frame model,a parametric representation of complex shape is *** adding some auxiliary curves,the feature frame model is divided into many box-like patches in three dimension or four-sided patches in two *** patches are built into parametric patches by using volume interpolation methods such as Coons *** on the parametric patches,isogeometic analysis is ***,the relationships are constructed among the size parameters,the control points and the physical performance *** the sensitivity matrix could be derived based on the *** size optimization is carried out in the first stage by taking the size parameters as *** on the result of size optimization,shape optimization with the constraints of stress is carried out in the second stage by taking the control points as *** planar complex shapes are taken as example to verify our *** results verify that the parametric modeling and structural optimization can be united together without model *** from this,the optimization design can be executed as a dark box operation without considering the concrete modeling and analysis by input of the sizes,constra

关键词： Isogeometric analysis parametric design structural optimization

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Addition of Niobium in Fe-13cr-4.5al-2mo Alloy Used as Atf Cladding: Effect on High Temperature Water Corrosion and In-Situ Electrochemistry

SSRN

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SSRN 2022年

作者： Liao, Jingjing Wang, Hui Wu, Jun Zhang, Wei Xu, Fei Sun, Hongying An, Xuguang Qiu, Shaoyu Chengdu University China Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of China Sichuan Chengdu610213 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Sichuan Chengdu610213 China School of Mechanical Engineering Anyang Institute of Technology Henan Anyang455002 China Interdisciplinary Materials Research Center Institute for Advanced Study Chengdu University Sichuan Chengdu610106 China

Niobium addition in candidate accident tolerant fuel (ATF) cladding FeCrAl alloy has received much attention, but its effect on high temperature water corrosion behavior has not been revealed. Four alloys with different Nb content (0wt%, 0.5wt%, 1.0wt% and 1.5wt%) based on Fe-13Cr-4.5Al-2Mo model alloy were designed, and the corrosion behavior was investigated by in-situ electrochemistry and microscopy. The in-situ electrochemistry analyses were carried out in 360 。C/19.0MPa lithiated and borated water connected with a loop system to monitor the water chemistry. Detailed studies on the oxide film formed after exposure for 85 days were conducted by focused ion bombarding and transmission electron microscopy. FeCrAl alloys have satisfactory corrosion resistance because of small corrosion currents and thin oxide films. Only monolayer multicrystal spinel oxide forms on alloy surface. Slight Nb addition (0.5% and 1.0wt%) benefits the corrosion resistance due to relatively large impedance of oxide and delayed oxidation of Fe2 Nb particles. Porosities with Fe depletion are spotted in oxide and especially severe in 1.5wt%-Nb alloy. Cathodic Tafel kinetics and corrosion mechanisms of FeCrAl are further discussed. © 2022, The Authors. All rights reserved.

关键词： Oxide films

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Subway rail transit monitoring by built-in sensor platform of smartphone

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Frontiers of Information technology & Electronic Engineering 2020年第8期21卷 1226-1238页

作者： Jian-li CONG Ming-yuan GAO Yuan WANG Rong CHEN Ping WANG School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of High-speed Railway Engineering Ministry of EducationChengdu 610031China College of Engineering and Technology Southwest UniversityChongqing 400716China National&Local Joint Engineering Laboratory of Intelligent Transmission and Control Technology Chongqing 400716China School of System Design and Intelligent Manufacturing Southern University of Science and TechnologyShenzhen 518055China

Smartphone,as a smart device with multiple built-in sensors,can be used for collecting information(e.g.,vibration and location).In this paper,we propose an approach for using the smartphone as a sensing platform to obtain real-time data on vehicle acceleration,velocity,and location through the development of the corresponding application software and thereby achieve the green concept based monitoring of the track condition during subway rail *** tests are conducted to verify the accuracy of smartphones in terms of the obtained data’s standard deviation(SD),Sperling index(SI),and International Organization for Standardization(ISO)-2631 weighted acceleration index(WAI).A vehicle-positioning method,together with the coordinate alignment algorithm for a Global Positioning system(GPS)free tunnel environment,is *** the time-domain integration method,the relationship between the longitudinal acceleration of a vehicle and the subway location is established,and the distance between adjacent stations of the subway is calculated and compared with the actual *** effectiveness of the method is verified,and it is confirmed that this approach can be used in the GPS-free subway tunnel *** is also found that using the proposed vehicle-positioning method,the integral error of displacement of a single subway section can be controlled to within 5%.This study can make full use of smartphones and offer a smart and eco-friendly approach for human life in the field of intelligent transportation systems.

关键词： Acceleration signals Smart monitoring Embedded sensors Smartphones Subway

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Correcting Climate Model Sea Surface Temperature Simulations with Generative Adversarial Networks:Climatology,Interannual Variability,and Extremes

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Advances in Atmospheric sciences 2024年第7期41卷 1299-1312页

作者： Ya WANG Gang HUANG Baoxiang PAN Pengfei LIN Niklas BOERS Weichen TAO Yutong CHEN BO LIU Haijie LI State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Earth System Modelling School of Engineering and DesignTechnical University of MunichOttobrunn 85521Germany Potsdam Institute for Climate Impact Research Potsdam 14412Germany Department of Mathematics and Global Systems Institute University of ExeterExeter EX44QEUK CMA Earth System Modeling and Prediction Centre(CEMC) Chinese Academy of Meteorological SciencesBeijing 100081China

Climate models are vital for understanding and projecting global climate change and its associated ***,these models suffer from biases that limit their accuracy in historical simulations and the trustworthiness of future *** these challenges requires addressing internal variability,hindering the direct alignment between model simulations and observations,and thwarting conventional supervised learning ***,we employ an unsupervised Cycle-consistent Generative Adversarial Network(CycleGAN),to correct daily Sea Surface Temperature(SST)simulations from the Community Earth system Model 2(CESM2).Our results reveal that the CycleGAN not only corrects climatological biases but also improves the simulation of major dynamic modes including the El Niño-Southern Oscillation(ENSO)and the Indian Ocean Dipole mode,as well as SST ***,it substantially corrects climatological SST biases,decreasing the globally averaged Root-Mean-Square Error(RMSE)by 58%.Intriguingly,the CycleGAN effectively addresses the well-known excessive westward bias in ENSO SST anomalies,a common issue in climate models that traditional methods,like quantile mapping,struggle to ***,it substantially improves the simulation of SST extremes,raising the pattern correlation coefficient(PCC)from 0.56 to 0.88 and lowering the RMSE from 0.5 to *** enhancement is attributed to better representations of interannual,intraseasonal,and synoptic scales *** study offers a novel approach to correct global SST simulations and underscores its effectiveness across different time scales and primary dynamical modes.

关键词： generative adversarial networks model bias deep learning El Niño-Southern Oscillation marine heatwaves

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A Solution Analysis of U.S. Weapon Equipment systems-of-systems Development and Application 7

A Solution Analysis of U.S. Weapon Equipment Systems-of-Syst...

引用

7th International Conference on Information science and Control Engineering, ICISCE 2020

作者： Lin, Menglong Yi, Shuanghui Zhang, Mengmeng Shu, Zhen National University of Defense Technology Science and Technology on Information Systems Engineering Laboratory Changsha China National Key Laboratory for Complex System Simulation Beijing China

ISBN: (纸本)9781728164069

In recent years, the development and deployment of the U.S. weapon equipment systems-of-systems (SoS) have yielded rich research results. However, there are still large gaps in the SoS development, joint testing, and design and acquisition of our own equipment SoS. The barriers of these steps have not yet been opened up. This article mainly analyzes the solutions of the U.S. weapon equipment SoS from three aspects, such as capability-based requirement generation and architecture design technology, interconnected-oriented integration test technology, and weapon equipment design and acquisition technology based on complex adaptive systems. We explore key technologies involved in order to form an overall understanding and explore related research approaches. © 2020 IEEE.

关键词： system of systems

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Nonstoichiometric Protic Ionic Liquids for Efficient Carbon Dioxide Capture

SSRN

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SSRN 2023年

作者： Wang, Litian Chen, Jie Li, Dan Li, Cuiping Qian, Lirong Xiong, Yang Xie, Zhiyong Wang, Shuai Zhou, Tongyao Gai, Baojia Wang, Yinuo Tianjin Key Laboratory of Film Electronic and Communication Devices School of Integrated Circuit Science and Engineering Tianjin University of Technology Tianjin300384 China School of Integrated Circuit Science and Engineering Tianjin University of Technology Tianjin300384 China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology China Tianjin Bohua Yongli Chemical Industry CO. Ltd Tianjin30045 China

Protic ionic liquids (PILs) have emerged as promising solvents for CO2 capture, offering great potential for the development of efficient CO2 absorbents. Understanding the relationship between the PILs’ structures and CO2absorption mechanisms is instructive for advancing their applicability. Herein, an innovative strategy for CO2 capture using nonstoichiometric PILs was demonstrated for the first time. These nonstoichiometric PILs composed of imidazole (Im) as a Brønsted acid and 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) as a Brønsted base with various ratios. They exhibited both low viscosities and remarkable CO2 loading capacities, reaching up to 0.194 g CO2 /g IL and 1.42 mol CO2 /mol IL at 0.1 atm and 40 °C. The distribution of neutral and ionic species in these nonstoichiometric PILs was determined using density functional theory (DFT) calculations and nuclear magnetic (NMR) spectroscopy analysis. Correlations between the mole ratio of Brønsted acid and base and the viscosities, conductivities, and CO2 absorption properties were observed. The mechanism of CO2 absorption was proposed from the spectral results and DFT calculations. The superior CO2 loading ability of these PILs can be attributed to the formation of the zwitterionic carbamic complexes through interactions between CO2 and the N atom in DBU. Additionally, the presentence of Im significantly avoided the dramatic increase in the viscosity of the absorbents during CO2 absorption. It is believed that the new insights into the CO2 mechanism will facilitate the rational design of PILs for CO2 capture in the future. © 2023, The Authors. All rights reserved.

关键词： Carbon dioxide

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MFCLIP: Multi-modal Fine-grained CLIP for Generalizable Diffusion Face Forgery Detection

arXiv

引用

arXiv 2024年

作者： Zhang, Yaning Wang, Tianyi Yu, Zitong Gao, Zan Shen, Linlin Chen, Shengyong Jinan250353 China Nanyang Technological University 50 Nanyang Ave Block N 4 639798 Singapore School of Computing and Information Technology Great Bay University Dongguan523000 China National Engineering Laboratory for Big Data System Computing Technology Shenzhen University Shenzhen518060 China Jinan250014 China The Key Laboratory of Computer Vision and System Ministry of Education Tianjin University of Technology Tianjin300384 China Computer Vision Institute College of Computer Science and Software Engineering Shenzhen University Shenzhen518060 China National Engineering Laboratory for Big Data System Computing Technology Shenzhen University Shenzhen China Shenzhen Institute of Artificial Intelligence and Robotics for Society Shenzhen518129 China Guangdong Key Laboratory of Intelligent Information Processing Shenzhen University Shenzhen518060 China

The rapid development of photo-realistic face generation methods has raised significant concerns in society and academia, highlighting the urgent need for robust and generalizable face forgery detection (FFD) techniques. Although existing approaches mainly capture face forgery patterns using image modality, other modalities like fine-grained noises and texts are not fully explored, which limits the generalization capability of the model. In addition, most FFD methods tend to identify facial images generated by GAN, but struggle to detect unseen diffusion-synthesized ones. To address the limitations, we aim to leverage the cutting-edge foundation model, contrastive language-image pre-training (CLIP), to achieve generalizable diffusion face forgery detection (DFFD). In this paper, we propose a novel multi-modal fine-grained CLIP (MFCLIP) model, which mines comprehensive and fine-grained forgery traces across image-noise modalities via language-guided face forgery representation learning, to facilitate the advancement of DFFD. Specifically, we devise a fine-grained language encoder (FLE) that extracts fine global language features from hierarchical text prompts. We design a multi-modal vision encoder (MVE) to capture global image forgery embeddings as well as fine-grained noise forgery patterns extracted from the richest patch, and integrate them to mine general visual forgery traces. Moreover, we build an innovative plug-and-play sample pair attention (SPA) method to emphasize relevant negative pairs and suppress irrelevant ones, allowing cross-modality sample pairs to conduct more flexible alignment. Extensive experiments and visualizations show that our model outperforms the state of the arts on different settings like cross-generator, cross-forgery, and cross-dataset evaluations. Copyright © 2024, The Authors. All rights reserved.

关键词： Alignment

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Architecture Transformation Research on Joint Border Defense systems-of-systems

Architecture Transformation Research on Joint Border Defense...

引用

作者： Mengmeng Zhang Shuanghui Yi Menglong Lin Honghui Chen Science and Technology on Information Systems Engineering Laboratory National Key Laboratory for Complex System Simulation

Currently,with the deepening of development and open of China's border,issues of border joint defense become increasingly *** means of cooperation and coordination are far from being able to align requirements;information systems of different joint defense units are difficult to interconnect and interoperate;the previous results of joint defense informatization are difficult to *** main reason is the lack of border joint defense information construction with a top-level design *** the lens of top-level design,this paper establishes a multi-viewpoint architecture framework and transformation process,develops the as-is and to-be joint defense architecture,and finally analyzes transformation principles from the as-is architecture to to-be *** paper mainly explores the architecture transformation mechanisms under the border joint defense scenario.

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Geometric Constellation Shaping for Wireless Optical Intensity Channels: An Information-Theoretic Approach

arXiv

引用

arXiv 2024年

作者： Zhou, Suhua Li, Tianqi Fang, Zhaoxi Zhou, Jing Zhang, Wenyi School of Automation Beijing Information Science and Technology University Beijing100192 China National Computer System Engineering Research Institute of China Beijing100083 China Department of Computer Science and Engineering Shaoxing University Shaoxing312000 China Henan Key Laboratory of Visible Light Communications Zhengzhou450002 China Department of Electronic Engineering and Information Science University of Science and Technology of China Hefei230027 China

A simple geometric shaping method is proposed for optical wireless communication systems based on intensity modulation and direct detection (IM/DD) from an information-theoretic perspective. Constellations consisting of equiprobable levels with exponential-like distribution are obtained, which possesses asymptotic optimality in the sense that the high-SNR capacity of average-intensity constrained optical intensity channel can be approached by such constellations with increasing size. All 2b levels (b ∈ N) of the obtained constellation can be represented by a basic level and b + 2 bits, thereby reducing the required resolution of the digital-to-analog converter (DAC) without affecting the asymptotic optimality. Achievable information rate evaluations verify the asymptotic optimality. As an example, error performance results of a simple 16-level LDPC coded modulation scheme show that a shaping gain of 0.65 dB can be obtained by applying the proposed constellation design. This method can also be applied to more specific IM/DD channel models, since it only requires a near-optimal continuous input distribution. © 2024, CC BY-NC-ND.

关键词： Digital to analog conversion

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Exploration and Practice of Hierarchical Graduation Project under the Background of science Collaborative Education and Engineering Education Accreditation 21

Exploration and Practice of Hierarchical Graduation Project ...

引用

Proceedings of the 5th International Conference on Advances in Artificial Intelligence

作者： Lilan Gao Yansong Tan Yanfang Sun Linwei Lv Bin Li Qijun Gao Xiaofei Wang Yijiao Zhao School of Mechanical Engineering_Tianjin Key Laboratory for Advanced Mechatronic System Design and intelligent Control_National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology China School of Mechanical Engineering_Tianjin Key Laboratory for Advanced Mechatronic System Design and intelligent Control Tianjin University of Technology China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology China

ISBN: (纸本)9781450390699

Graduation project is an important integrated practice segment for undergraduate education, since the quality of undergraduate education can be directly evaluated by the quality of graduation project. Under the background of science collaborative education and engineering education accreditation, it is necessary to explore an intelligent and integrated graduation project system to train students by all sorts of engineering and research projects, thus improve students' practical ability and innovation ability. This paper first analyzed the problems of the graduation project in the major of process equipment and control engineering, then introduced a novel hierarchical graduation project system to adapt to the concept of science collaborative education and engineering education. By putting the novel graduation project system into effect, the quality of graduation project has significantly improved.

关键词： science collaborative education Hierarchical graduation project Engineering education accreditation Education reform

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