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MEM-TET: Improved Triplet Network for Intrusion Detection System

Computers, Materials & Continua 2023年第7期76卷 471-487页

作者： Weifei Wang Jinguo Li na Zhao Min Liu College of Computer Science and Technology Shanghai University of Electric PowerShanghai201306China national Pilot School of Software Yunnan UniversityKunming650504China

With the advancement of network communication technology,network traffic shows explosive ***,network attacks occur *** intrusion detection systems are still the primary means of detecting ***,two challenges continue to stymie the development of a viable network intrusion detection system:imbalanced training data and new undiscovered ***,this study proposes a unique deep learning-based intrusion detection *** use two independent in-memory autoencoders trained on regular network traffic and attacks to capture the dynamic relationship between traffic features in the presence of unbalanced training *** the original data is fed into the triplet network by forming a triplet with the data reconstructed from the two encoders to ***,the distance relationship between the triples determines whether the traffic is an *** addition,to improve the accuracy of detecting unknown attacks,this research proposes an improved triplet loss function that is used to pull the distances of the same class closer while pushing the distances belonging to different classes farther in the learned feature *** proposed approach’s effectiveness,stability,and significance are evaluated against advanced models on the Android Adware and General Malware Dataset(AAGM17),Knowledge Discovery and Data Mining Cup 1999(KDDCUP99),Canadian Institute for Cybersecurity Group’s Intrusion Detection Evaluation Dataset(CICIDS2017),UNSW-NB15,Network Security Lab-Knowledge Discovery and Data Mining(NSL-KDD)*** achieved results confirmed the superiority of the proposed method for the task of network intrusion detection.

关键词： Intrusion detection memory-augmented autoencoder deep metric learning imbalance data

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重稀土掺杂烧结钕铁硼磁体的晶界调控研究进展

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稀土 2024年第2期45卷 31-40页

作者：孔梦燃田晓王瑜夏峰孙彩娜姚占全内蒙古师范大学物理与电子信息学院功能材料物理与化学自治区重点实验室内蒙古呼和浩特010022 内蒙古师范大学稀土功能和新能源储能材料内蒙古自治区工程研究中心内蒙古呼和浩特010022 包头金山磁材有限公司内蒙古包头014020 内蒙古农业大学水利与土木建筑工程学院内蒙古呼和浩特010018

随着低碳经济的提出,烧结钕铁硼磁体作为新能源汽车及其他高新技术的核心材料越来越受到人们的关注,同时对其性能也提出了更高的要求,高矫顽力、高剩磁和大磁能积的永磁体成为人们追求的目标。烧结钕铁硼磁体的磁性能与微观结构中晶界... 详细信息

随着低碳经济的提出,烧结钕铁硼磁体作为新能源汽车及其他高新技术的核心材料越来越受到人们的关注,同时对其性能也提出了更高的要求,高矫顽力、高剩磁和大磁能积的永磁体成为人们追求的目标。烧结钕铁硼磁体的磁性能与微观结构中晶界成分、分布以及体积分数等密切相关。利用新型工艺在合金中掺杂重稀土可以很好地调控磁体的微观结构,从而在保持剩磁不变的基础上,提高磁体的矫顽力和磁能积。本文在详细介绍两种新型掺杂技术的基础上,梳理了近几十年来国内外通过掺杂重稀土金属、重稀土化合物及重稀土合金来调控磁体晶界结构、提高磁体矫顽力方面的最新研究成果,为进一步提高烧结钕铁硼磁体性能提供参考。

关键词：烧结钕铁硼重稀土掺杂晶界扩散晶界调控

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Multi-objective layout optimization of a satellite module using the Wang-Landau sampling method with local search

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Frontiers of Information Technology & Electronic Engineering 2016年第6期17卷 527-542页

作者： Jing-fa LIU Liang HAO Gang LI Yu XUE Zhao-xia LIU Juan HUANG Jiangsu Engineering Center of Network Monitoring Nanjing University of Information Science&TechnologyNanjing 210044China School of Computer&Software Nanjing University of Information Science&TechnologyNanjing 210044China School of Mathematics and Statistics Nanjing University of Information Science&TechnologyNanjing 210044China Office of lnformationization Construction and Management Nanjing University of Information Science&TechnologyNanjing 210044China

The layout design of satellite modules is considered to be NP-hard. It is not only a complex coupled system design problem but also a special multi-objective optimization problem. The greatest challenge in solving this problem is that the function to be optimized is characterized by a multitude of local minima separated by high-energy barriers. The Wang-Landau(WL) sampling method, which is an improved Monte Carlo method, has been successfully applied to solve many optimization problems. In this paper we use the WL sampling method to optimize the layout of a satellite module. To accelerate the search for a global optimal layout, local search(LS) based on the gradient method is executed once the Monte-Carlo sweep produces a new layout. By combining the WL sampling algorithm, the LS method, and heuristic layout update strategies, a hybrid method called WL-LS is proposed to obtain a final layout scheme. Furthermore, to improve significantly the efficiency of the algorithm, we propose an accurate and fast computational method for the overlapping depth between two objects(such as two rectangular objects, two circular objects, or a rectangular object and a circular object) embedding each other. The rectangular objects are placed orthogonally. We test two instances using first 51 and then 53 objects. For both instances, the proposed WL-LS algorithm outperforms methods in the literature. Numerical results show that the WL-LS algorithm is an effective method for layout optimization of satellite modules.

关键词： Packing Layout design satellite module Wang-Landau algorithm

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Fusion expression of pedA gene to obtain biologically active pediocin PA-1 in Escherichia coli

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第1期12卷 65-71页

作者： Shan-na LIU Ye HAN Zhi-jiang ZHOU School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

Two heterologous expression systems using thioredoxin (trxA) as a gene fusion part in Escherichia coli were developed to produce recombinant pediocin *** PA-1 structural gene pedA was isolated from Pediococcus acidilactici PA003 by the method of polymerase chain reaction (PCR),then cloned into vector pET32a(+),and expressed as thioredoxin-PedA fusion protein in the host strain *** BL21 (DE3).The fusion protein was in the form of inclusion body and was refolded before purification by nickel-iminodiacetic acid (Ni-IDA) agarose resin *** activity of recombinant pediocin PA-1 was analyzed after cleavage of the fusion protein by *** diffusion test revealed that 512-arbitrary unit (AU) recombinant pediocin PA-1 was obtained from 1 ml culture medium of *** (pPA003PED1) using Listeria monocytogenes as the indicator ***-PedA fusion gene was further cloned into pET20b(+).Thioredoxin-PedA fusion protein was detected in both the periplasmic and cytoplasmic *** recombinant pediocin PA-1 from the soluble fraction attained 384 AU from 1 ml culture medium of *** (pPA003PED2).Therefore,biologically active pediocin PA-1 could be obtained by these two hybrid gene expression methods.

关键词： Bacteriocin Fusion expression Inclusion body Pediocin PA-1 Thioredoxin

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混合配体构筑的Cd(Ⅱ)配合物的合成及其荧光性质

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中山大学学报（自然科学版）（中英文） 2024年第3期63卷 113-118页

作者：王凯民顾雄杨冲福邓娜叶艳青周强马钰璐云南民族大学化学与环境学院云南昆明650504 昆明医科大学药学院/云南省天然药物药理重点实验室云南昆明650500 昆明医科大学现代生物医药产业学院云南昆明650500

采用含N刚性配体4,4'-联吡啶(bpy)与两性离子配体4-羧基-1-(3-羧基苄基)吡啶-1-氯化物(H_(2)LCl)混合的模式,利用液相扩散法,在室温下与Cd^(2+)自组装构筑了一例结构新颖的配合物{[Cd_(2.5)(L)_(2)(bpy)_(2)Cl(NO_(3))(H_(2)O)_(3)]·(NO_(3))·2H_(2)O}。通过单晶X衍射、Hirshfeld表面与二维指纹图、粉末X射线衍射、热重及固体荧光对配合物的结构及性质进行了分析。研究表明,该配合物为[Cd(bpy)_(2)]对称棒状单元与两条平行环链结构组成的一维梯子形链。借助丰富的分子间相互作用(π…π堆积、O—H…O及C—H…O氢键)配合物的梯子形链平行互穿,相互堆积,最终形成稳定的三维超分子结构。此外,由于d10金属离子的存在,配合物在425~466 nm波长范围内显示出与配体H_(2)LCl相似但强度增强的浅绿色荧光,CIE色坐标为(0.2870,0.3346)。

关键词：配合物晶体结构液相扩散分子间相互作用固体荧光

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Diffusion occupation time before exiting

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Frontiers of Mathematics in China 2014年第4期9卷 843-861页

作者： Yingqiu LI Suxin WANG Xiaowen ZHOU na ZHU College of Mathematics and Computing Sciences Changsha University of Science and Technology Changsha 410004 China College of Mathematics Nankai University Tianjin 300071 China Department of Mathematics and Statistics Concordia University MontrealQuebec H3G 1M8 Canada

Using the approach of D. Landriault et al. and B. Li and X. Zhou, for a one-dimensional time-homogeneous diffusion process X and constants c 〈 a 〈 b 〈 d, we find expressions of double Laplace transforms of the form Ex[e--θTd--λ∫o Td1a 〈Xs〈b ds; Td 〈 Tc], where Tx denotes the first passage time of level x. As applications, we find explicit Laplace transforms of the corresponding occupation time and occupation density for the Brownian motion with two-valued drift and that of occupation time for the skew Ornstein- Uhlenbeck process, respectively. Some known results are also recovered.

关键词： Diffusion exit problem occupation time occupation density localtime Brownian motion with two-valued drift skew Ornstein-Uhlenbeck (OU)process

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Second order potential vorticity and its potential applications

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Science China Earth Sciences 2014年第10期57卷 2428-2434页

作者： GAO ShouTing XU PengCheng LI na ZHOU YuShu Key Laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric PhysicsChinese Academy of Sciences Institute of Applied Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences University of Chinese Academy of Sciences

A new invariant, the second order potential vorticity(SPV), is derived in this paper. SPV is the dot product of vorticity and the potential vorticity(PV) gradient, and is proven conservative for a compressible, adiabatic and frictionless atmosphere. Research shows that the new invariant may be used to indicate the evolution of PV, because SPV includes all the information that determines PV evolution: the wind field, and the PV gradient. Furthermore, SPV is capable of diagnosing heavy precipitation because of the strong signals it presents in areas of heavy rainfall. SPV also shows great potential as a comprehensive conserved quantity for indicating the dynamical tropopause and baroclinic instability.

关键词： potential vorticity second order potential vorticity PV evolution PV gradient heavy rainfall

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A Computational Study on Lateral Flight Stability of the Cranefly in Hover

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Computer Modeling in Engineering & Sciences 2021年第8期128卷 669-685页

作者： na Xu Shuaizhi Zhou Chunchen Zhang Xiaolei Mou School of Electromechanical and Automotive Engineering Yantai UniversityYantai264005China School of Civil Engineering Yantai UniversityYantai264005China

The dynamic flight stability of hovering insects includes the longitudinal and lateral *** results have shown that for the majority of hovering insects the same longitudinal natural modes are identified and the hovering flight in longitudinal is ***,in lateral,the modal structure for hovering insects could be different and the stability property of lateral disturbance motion is not as robust as that of longitudinal *** cranefly possesses larger aspect ratio and lower Reynolds number,and such differences in morphology and kinematics may make the lateral dynamic stability *** this paper,the lateral flight stability of the cranefly in hover is investigated by numerical ***,the stability derivatives are acquired by solving the incompressible navier–Stokes ***,the dynamic stability characteristics are checked by analyzing the eigenvalues and eigenvectors of the linearized *** results indicate that the lateral dynamic modal structure of cranefly is different from most other insects,consisting of three natural modes,and the weakly oscillatory mode illustrates the hovering lateral flight is nearly *** neutral stability is mainly caused by the negative derivative of roll-moment ***-velocity,which can be attributed to the weaker‘changingLEV-axial-velocity’*** results suggest that insects in nature may exhibit different dynamic stabilities with different morphological and kinematic parameters,which should be considered in the designs of flapping wing air vehicles.

关键词： Flapping flight cranefly lateral flight stability natural modes of motion computational fluid dynamics

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Hybrid Modeling for Soft Sensing of Molten Steel Temperature in LF

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Journal of Iron and Steel Research International 2009年第4期16卷 1-6页

作者： TIAN Hui-xin MAO Zhi-zhong WANG An-na School of Electrical and Automation Engineering Tianjin Polytechnic University Tianjin 300160 China School of Information Science and Engineering Northeastern University Shenyang 110004 Liaoning China Key Laboratory of Integrated Automation of Process Industry of Ministry of Education NortheasternUniversity Shenyang 110004 Liaoning China

Aiming at the limitations of traditional thermal model and intelligent model, a new hybrid model is established for soft sensing of the molten steel temperature in LF. Firstly, a thermal model based on energy conservation is described; and then, an improved intelligent model based on process data is presented by ensemble ELM （extreme learning machine） for predicting the molten steel temperature in LF. Secondly, the self-adaptive data fusion is pro- posed as a hybrid modeling method to combine the thermal model with the intelligent model. The new hybrid model could complement mutual advantage of two models by combination. It can overcome the shortcoming of parameters obtained on-line hardly in a thermal model and the disadvantage of lacking the analysis of ladle furnace metallurgical process in an intelligent model. The new hybrid model is applied to a 300 t LF in Baoshan Iron and Steel Co Ltd for predicting the molten steel temperature. The experiments demonstrate that the hybrid model has good generalization performance and high accuracy.

关键词： ladle furnace hybrid modeling soft sensing thermal model data fusion

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季也蒙念珠菌肺炎1例并文献复习

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中华医院感染学杂志 2024年第6期34卷 852-856页

作者：李倩曲娜马佑平张伟华韩国敬武装警察部队宁夏回族自治区总队医院内科宁夏银川750001 解放军总医院第一医学中心呼吸与危重症科北京100853

目的总结季也蒙念珠菌肺炎的病因、临床表现、影像学特点、诊断、治疗,提高对肺部真菌病的警觉和认知,减少漏诊、误诊。方法回顾性分析2023年3月解放军总医院第一医学中心收治的1例季也蒙念珠菌肺炎患者的临床资料(主要临床症状、用... 详细信息

目的总结季也蒙念珠菌肺炎的病因、临床表现、影像学特点、诊断、治疗,提高对肺部真菌病的警觉和认知,减少漏诊、误诊。方法回顾性分析2023年3月解放军总医院第一医学中心收治的1例季也蒙念珠菌肺炎患者的临床资料(主要临床症状、用药及治疗史、影像学表现、基础疾病、主要阳性体征),对诊疗经过进行总结分析,并结合文献检索进行病例复习。结果患者有2型糖尿病、冠状动脉粥样硬化性心脏病、甲状腺功能减退症、阵发性房颤病史。主要症状表现为咳嗽、咳痰、喘憋。实验室检查提示真菌(1,3)-β-D-葡聚糖增高,3次痰培养、1次肺泡灌洗液培养及灌洗液宏基因二代测序(mNGS)均检出季也蒙假丝酵母。胸部CT可见双肺散在多发斑片状磨玻璃影及条索状密度增高影。经氟康唑治疗后症状不缓解,复查胸部CT病灶未见吸收,更换为伏立康唑治疗,症状减轻,复查胸部CT双肺感染明显好转,患者病情稳定出院。结论季也蒙念珠菌肺炎少见,主要发生在免疫功能低下的患者,治疗上对三唑类、两性霉素B、氟胞嘧啶敏感,对棘白菌素类敏感性较差,推荐根据药敏用药。

关键词：真菌性肺炎季也蒙假丝酵母肺部感染氟康唑伏立康唑宏基因二代测序

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