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Suppression of Neoclassical Tearing Modes Towards Stationary High-Beta Plasmas in JT-60U

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Plasma Science and Technology 2006年第1期8卷 36-40页

作者： A.ISAYAMA Japan Atomic Energy Agency NakaIbaraki 311-0193JapantheJT-60Team

Results from stabilization of neoclassical tearing modes （NTMs） in JT-60U are described. NTM stabilization and confinement improvement have been demonstrated by employing a real-time NTM stabilization system, where the identification of the location of an NTM and the optimization of the injection angle of the electron cyclotron wave are performed in real time. Also, a high-beta plasma with the normalized beta of 3 has been sustained by suppressing NTM by applying the electron cyclotron current drive （ECCD） before the onset （＇preemptive ECCD＇）. In addition, a simulation code for analysis of the NTM evolution has been developed by combining the modified Rutherford equation with the transport code TOPICS. It is found that the simulation well reproduces the NTM behavior in JT-60U. The simulation also shows that the ECCD width is also important for NTM stabilization, and that the EC wave power for complete stabilization can be reduced by narrowing the ECCD profile.

关键词： neoclassical tearing mode electron cyclotron current drive tokamak

Fabrication and characterization of 3D scaffold using 3D plotting system

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Chinese Science Bulletin 2010年第1期55卷 94-98页

作者： LEE Jun-Hee PARK Su-A PARK KoEun KIM Jae-Hyun KIM Kyung-Shik LEE Jihye Kim WanDoo Bio-Mechatronics team Division of Nano-Machinery Korea Institute of Machinery and Materials (KIMM) Nano-Mechanics team Division of Nano-Machinery Korea Institute of Machinery and Materials (KIMM) Nano-Mechatronics team Division of Nano-Machinery Korea Institute of Machinery and Materials (KIMM)

In this paper, we design and fabricate a 3D scaffold using rapid prototyping (RP) technology for tissue engineering. The scaffold should have a three-dimensional interconnected pore network. We fabricate a polycaprolactone (PCL) scaffold with interconnecting pores and uniform porosity for cell ingrowth using a 3D plotting system. In order to keep the three dimensional shape under mechanical loading while implanted, we design an oscillating nozzle system to increase elastic modulus and yield strength of PCL strand. We characterize the influence of pore geometry, compressive modulus of the scaffold, elastic modulus and yield strength of the strand using SEM, dynamical mechanical analysis (DMA) and Nano-UTM. Finally the cell responses on scaffolds are observed.

关键词：三维形状绘图系统表征支架制作动态机械分析弹性模量细胞反应

Differences in Precipitation and Related Wind Dynamics and Moisture and Heat Features in Separate Areas of the South China Sea before and after Summer Monsoon Onset

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Advances in Atmospheric Sciences 2024年第8期41卷 1643-1660页

作者： Chunyan ZHANG Donghai WANG Kaifeng ZHANG Wanwen HE Yanping ZHENG Yan XU Guangdong Meteorological Data Center Guangdong Meteorological BureauGuangzhou 510640China School of Atmospheric Sciences Sun Yat-sen UniversityGuangdong Province Key Laboratory for Climate Change and Natural Disaster StudiesKey Laboratory of Tropical Atmosphere-Ocean SystemMinistry of EducationZhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China National Observation and Research Station of Coastal Ecological Environments in Macao Macao Environmental Research InstituteMacao University of Science and TechnologyMacao SAR 999078China Foshan Meteorological Service Foshan 528000China Ningjiang District Meteorological Bureau Songyuan 138000China

Using surface and balloon-sounding measurements, satellite retrievals, and ERA5 reanalysis during 2011–20, this study compares the precipitation and related wind dynamics, moisture and heat features in different areas of the South China Sea(SCS) before and after SCS summer monsoon onset(SCSSMO). The rainy sea around Dongsha(hereafter simply referred to as Dongsha) near the north coast, and the rainless sea around Xisha(hereafter simply referred to as Xisha) in the western SCS, are selected as two typical research subregions. It is found that Dongsha, rather than Xisha, has an earlier and greater increase in precipitation after SCSSMO under the combined effect of strong low-level southwesterly winds, coastal terrain blocking and lifting, and northern cold air. When the 950-h Pa southwesterly winds enhance and advance northward, accompanied by strengthened moisture flux, there is a strong convergence of wind and moisture in Dongsha due to a sudden deceleration and rear-end collision of wind by coastal terrain blocking. Moist and warm advection over Dongsha enhances early and deepens up to 200 h Pa in association with the strengthened upward motion after SCSSMO, thereby providing ample moisture and heat to form strong precipitation. However, when the 950-h Pa southwesterly winds weaken and retreat southward, Xisha is located in a wind-break area where strong convergence and upward motion centers move in. The vertical moistening and heating by advection in Xisha enhance later and appear far weaker compared to that in Dongsha, consistent with later and weaker precipitation.

关键词： Dongsha Xisha South China Sea summer monsoon onset precipitation wind dynamics moisture heat

WAF-Based Chinese Character Recognition for Spam Image Filtering

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Chinese Journal of Electronics 2018年第5期27卷 1050-1055页

作者： LI Siyuan LI Ruiguang XU Yuan ZHOU Hao YAN Hanbing XU Bin ZHANG Honggang Beijing University of Posts and Telecommunication National Computer Network Emergency Response Technical team Coordination Center of China

We address the problem of filtering image spam, a kind of rapidly spread spam in which the text is embedded into images to defeat text-based spam ***, we focus on image spam with Chinese text as "spam" which is a more challenging task. A popular way to detect image spam is by Optical character recognition(OCR) system, which detects and recognizes the embedded text, then followed by a text classifier that discriminate spam from ham. However, spammers start to obscure image text to prevent OCR system discovering the spam text. To compensate for the shortcomings of OCR system, a novel method which essentially is a keyword reconstruction algorithm based on Word activation force(WAF) model is proposed. It is effective on discovering keywords, hence is benefit for the later classification stage and notably improve the performance of image spam filtering. The experimental results on a personal data set of spam images(publicly available) validate the effectiveness of our approach that outperforms the original OCR system in practical usage with complex background in image spam.

关键词： Spam image Chinese character recognition Keyword reconstruction Word activation force

Multi-parameter fusion algorithm for auto focus

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Chinese Optics Letters 2010年第6期8卷 580-583页

作者：罗钧孙力吴克松陈伟民付丽 Key Laboratory of Optoelectronic Technology and system Ministry of EducationChongqing University

A multi-parameter fusion algorithm（MPFA） for auto-focus（AF） is *** image sharpness evaluation algorithm（ISEA） and zoom tracking method（ZTM） are combined for *** zoom motor position （z） and background complexity（c） are regarded as the main parameters of this algorithm.A priority table depending on z and c is *** ISEA or ZTM is adopted according to the priority table value. The hardware implementation of the MPFA on Texas Instruments＇ Davinci digital signal processor is also *** show that the proposed scheme provides faster focusing compared with the conventional approaches.

关键词： Algorithms Digital signal processors Hardware Signal processing Tracking (position)

Application of Mobile Agent in an ATM Network Management system

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Application of Mobile Agent in an ATM Network Management Sys...

Learning the optimal state-feedback via supervised imitation learning

2000 International Conference on Communication Technology(WCC2000·ICCT2000)

作者： Liu Qianli Dai Hao Graduate team 2 Institute of Communication Engineering

ISBN: (纸本)0780363949

＜正＞Mobile Agent（MA） technology presents an important abstraction mechanism when designing distributed environments and allows the user to manage distributed information indirectly through their mobile *** this paper we discuss the application of MA in an ATM network management（NM） *** management framework and implementation are *** advantage of using MA is apparent by an performance comparison with SNMP.

关键词： ATM NM Mobile Agent SNMP CMIP

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Astrodynamics 2019年第4期3卷 361-374页

作者： Dharmesh Tailor Dario Izzo Advanced Concepts team European Space AgencyNoondwijk2201 AZthe Netherlands

Imitation learning is a control design paradigm that seeks to learn a control policy reproducing demonstrations from expert *** substituting expert demonstrations for optimal behaviours,the same paradigm leads to the design of control policies closely approximating the optimal *** approach requires training a machine learning algorithm(in our case deep neural networks)directly on state-control pairs originating from optimal *** have shown in previous work that,when restricted to low-dimensional state and control spaces,this approach is very successful in several deterministic,non-linear problems in *** this work,we refine our previous studies using as a test case a simple quadcopter model with quadratic and time-optimal objective *** describe in detail the best learning pipeline we have developed,that is able to approximate via deep neural networks the state-feedback map to a very high *** introduce the use of the softplus activation function in the hidden units of neural networks showing that it results in a smoother control profile whilst retaining the benefits of *** show how to evaluate the optimality of the trained state-feedback,and find that already with two layers the objective function reached and its optimal value differ by less than one *** later consider also an additional metric linked to the system asymptotic behaviour-time taken to converge to the policy’s fixed *** respect to these metrics,we show that improvements in the mean absolute error do not necessarily correspond to better policies.

关键词： optimal control deep learning imitation learning G&CNET

A new strengthening mechanism driven by disruptive shear and solute segregation during warm rolling in 1.4 GPa class 12.5 wt% Al added-FeMnC ultra-lightweight steel

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Journal of Materials Science & Technology 2023年第26期157卷 174-188页

作者： Chiwon Kim Hyun-Uk Hong Joonoh Moon Bong Ho Lee Seong-Jun Park Chang-Hoon Lee Department of Materials Convergence and system Engineering Changwon National University 20 Changwondaehak-roChangwonGyeongnam 51140Republic of Korea Advanced Analysis team Daegu Gyeongbuk Institute of Science and Technology 333 Technojungang-daeroDaegu42988Republic of Korea Ferrous Alloy Department Korea Institute of Materials Science 797 ChangwondaeroChangwonGyeongnam 51508Republic of Korea

Novel strengthening of Fe-29.1Mn-12.5Al-1.35C-4.95Cr steel achieved by warm rolling was *** solution-treated steel consisted of aγ-matrix containing nano-sizedκ-carbide((Fe,Mn)_(3) AlC)and elongated prior ferrite,which was transformed into FeAl-type B2 and Fe_(3) Al-type D0_(3) *** solution-treated steel exhibited poor strain hardening owing to glide softening associated withκ-carbide shearing by ***,after warm rolling with a reduction ratio of 30%at 300℃,the yield and tensile strengths significantly increased from 917 to 1300 MPa and 1025 to 1419 MPa,*** tensile test conducted at 300℃to simulate warm rolling exhibited serrated flows,indicating dy-namic strain aging(DSA).Atom probe tomography exhibited that the C atoms inκ-carbide were swept away along the slip direction by disruptive shear during rolling at 300℃.The swept C atoms along the slip direction interacted strongly with dislocations at 300℃,with repeated pinning and breakaway of dislocations from the C *** contributed to significant strengthening owing to the formation of a solute-rich atmosphere after warm *** results of the tensile tests at 300℃indicated that the de-gree of strengthening was proportional to the pre-strain *** strength of 1.4 GPa can be achieved with good ductility(17%elongation)by warm *** novel warm-rolling strengthening method ex-pedites the potential application of Fe-29.1Mn-12.5Al-1.35C-4.95Cr as a 1.4 GPa class ultra-lightweight steel.

关键词： FeMnAlC Cr addition κ-carbide Dynamic strain aging Strengthening

Sigma-Mixed Unscented Kalman Filter-Based Fault Detection for Traction systems in High-Speed Trains

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Chinese Journal of Electronics 2023年第5期32卷 982-991页

作者： CHENG Chao WANG Weijun MENG Xiangxi SHAO Haidong CHEN Hongtian Department of Computer Science and Technology Changchun University of Technology Department of Mathematics and Statistics Changchun University of Technology Institute of system Research China Industrial Control Systems Cyber Emergency Response Team Department of Mechanical and Vehicle Engineering Hunan University Department of Chemical and Materials Engineering University of Alberta

Fault detection(FD) for traction systems is one of the active topics in the railway and academia because it is the initial step for the running reliability and safety of high-speed trains. Heterogeneity of data and complexity of systems have brought new challenges to the traditional FD methods. For addressing these challenges, this paper designs an FD algorithm based on the improved unscented Kalman filter(UKF) with consideration of performance degradation. It is derived by incorporating a degradation process into the state-space *** network topology of traction systems is taken into consideration for improving the performance of state estimation. We first obtain the mixture distribution by the mixture of sigma points in UKF. Then, the Lévy process with jump points is introduced to construct the degradation model. Finally, the moving average interstate standard deviation(MAISD) is designed for detecting *** the proposed methods via a traction systems in a certain type of trains obtains satisfactory results.

关键词： Degradation Network topology Fault detection Rail transportation State-space methods Safety Kalman filters