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Use of subword tokenization for domain generation algorithm classification

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Cybersecurity 2024年第2期7卷 1-12页

作者： Sea Ran Cleon Liew ngai Fong Law University of Waterloo WaterlooCanada Department of Electrical and Electronic Engineering The Hong Kong Polytechnic UniversityKowloonHong Kong

Domain name generation algorithm(DGA)classification is an essential but challenging *** feature-extract-ing machine learning(ML)methods and deep learning(DL)models such as convolutional neural networks and long short-term memory have been ***,the performance of these approaches varies with different types of *** features in the ML methods can characterize random-looking DGAs better than Word-looking *** improve the classification performance on word-looking DGAs,subword tokenization is employed for the DL *** experimental results proved that the subword tokenization can provide excellent classification performance on the word-looking *** then propose an integrated scheme that chooses an appropriate method for DGA classification depending on the nature of the *** show that the integrated scheme outperformed existing ML and DL methods,and also the subword DL methods.

关键词： Botnet detection Domain names Network security Machine learning-based botnet detection

Shear behavior and off-fault damage of saw-cut smooth and tension-induced rough joints in granite

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1216-1230页

作者： Fanzhen Meng Feili Wang Louis ngai Yuen Wong Jie Song Muzi Li Chuanqing Zhang Liming Zhang College of Science Qingdao University of TechnologyQingdao266033China Department of Earth Sciences The University of Hong KongPokfulamHong KongChina State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China Cooperative Innovation Center of Engineering Construction and Safety Shandong Peninsula Blue Economic Zone Qingdao266033China

The damage of rock joints or fractures upon shear includes the surface damage occurring at the contact asperities and the damage beneath the shear surface within the host *** latter is commonly known as off-fault damage and has been much less investigated than the surface *** main contribution of this study is to compare the results of direct shear tests conducted on saw-cut planar joints and tension-induced rough granite joints under normal stresses ranging from 1 MPa to 50 *** shear-induced off-fault damages are quantified and compared with the optical microscope *** results clearly show that the planar joints slip stably under all the normal stresses except under 50 MPa,where some local fractures and regular stick-slip occur towards the end of the *** post-peak stress drop and stick-slip occur for all the rough *** residual shear strength envelopes for the rough joints and the peak shear strength envelope for the planar joints almost *** root mean square(RMS)of asperity height for the rough joints decreases while it increases for the planar joint after shear,and a larger normal stress usually leads to a more significant decrease or increase in ***,the extent of off-fault damage(or damage zone)increases with normal stress for both planar and rough joints,and it is restricted to a very thin layer with limited micro-cracks beneath the planar joint *** comparison,the thickness of the damage zone for the rough joints is about an order of magnitude larger than that of the planar joints,and the coalesced micro-cracks are generally inclined to the shear direction with acute *** findings obtained in this study contribute to a better understanding on the frictional behavior and damage characteristics of rock joints or fractures with different roughness.

关键词： Planar joint Rough joint Shear behavior Off-fault damage Micro-cracks

An improved pulse coupled neural networks model for semantic IoT

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Digital Communications and Networks 2024年第3期10卷 557-567页

作者： Rong Ma Zhen Zhang Yide Ma Xiping Hu Edith C.H.ngai Victor C.M.Leung School of Information Science and Engineering Lanzhou UniversityLanzhou 730000China School of Medical Technology Beijing Institute of TechnologyBeijing100081China Department of Electrical and Electronic Engineer The University of Hong KongHong Kong 999077China College of Computer Science and Software Engineering Shenzhen UniversityShenzhen 518060China Department of Electrical and Computer Engineering the University of British ColumbiaVancouverBC V6T 1Z4Canada

In recent years,the Internet of Things(IoT)has gradually developed applications such as collecting sensory data and building intelligent services,which has led to an explosion in mobile data ***,with the rapid development of artificial intelligence,semantic communication has attracted great attention as a new communication ***,for IoT devices,however,processing image information efficiently in real time is an essential task for the rapid transmission of semantic *** the increase of model parameters in deep learning methods,the model inference time in sensor devices continues to *** contrast,the Pulse Coupled Neural Network(PCNN)has fewer parameters,making it more suitable for processing real-time scene tasks such as image segmentation,which lays the foundation for real-time,effective,and accurate image ***,the parameters of PCNN are determined by trial and error,which limits its *** overcome this limitation,an Improved Pulse Coupled Neural Networks(IPCNN)model is proposed in this *** IPCNN constructs the connection between the static properties of the input image and the dynamic properties of the neurons,and all its parameters are set adaptively,which avoids the inconvenience of manual setting in traditional methods and improves the adaptability of parameters to different types of *** segmentation results demonstrate the validity and efficiency of the proposed self-adaptive parameter setting method of IPCNN on the gray images and natural images from the Matlab and Berkeley Segmentation *** IPCNN method achieves a better segmentation result without training,providing a new solution for the real-time transmission of image semantic information.

关键词： Internet of things(IoT) Semantic information Real-time application Improved pulse coupled neural network Image segmentation

Early-onset primary torsional dystonia in a 4-generation Chinese family with a mutation in the DYT1 gene

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Chinese Medical Journal 2005年第10期118卷 873-876页

作者： YEUNG wai Lan LAM Ching Wan CHENG wai Tsoi SIN ngai Chuen WONG Wing Kin WONG chun Nei TSE Ka Ming FOK Tai Fai Departments of Paediatrics Prince of Wales HospitalThe Chinese University of Hong KongHong KongChina Chemical Patholog Prince of Wales HospitalThe Chinese University of Hong KongHong KongChina Department of Paediatrics and Adolescent Medicine Queen Mary HospitalUniversity of Hong Kong Nuclear Medicine&PET Division Scanning DepartmentSt.Teresa’s HospitalHong KongChina

Primary torsion dystonia(PTD)is a clinically and genetically heterogeneous movement *** least thirteen different types of dystonia can be distinguished on a genetic basis.~1 The DYT1 gene was first mapped by Ozelius et al in 1989.~2(Kramer et)al^3 linked the same locus to PTD in 12 Ashkenazi Jewish families in *** patients with early-onset generalized PTD were caused by the same three base pair(GAG)deletion in the DYT1 gene on chromosome 9q34.^(1,4,5)The product of the gene is a protein called torsinA.~5(Although the)function of this protein is as yet uncertain,it is widely distributed throughout the brain with high levels in the substantia nigra compacta dopamine neurones.

关键词： DYT1 gene dystonia positron emission tomography

Effect of Rolling on a Warm Compacted Ti_3SiC_2 Particulate Reinforced Cu Matrix Composite

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稀有金属材料与工程 2011年第S3期40卷 56-58页

作者： ngai Tungwai National Engineering Research Center of Near-net-shape Forming Technology for Metallic Materials South China University of Technology

Warm compaction was employed to fabricate a Ti3SiC2 particulate reinforced copper matrix composite for electro-friction application. Copper matrix composite reinforced with 5wt% of copper-coated Ti3SiC2 particulates were prepared by compacting mixed powder with a pressure of 700 MPa at 145 ℃, and then sintered at 1000 ℃ under cracked ammonia atmosphere for 60 min. In order to improve the density, rolling process was applied on the sintered samples, their density, hardness, electrical conductivity, ultimate tensile strength and tribological behaviors were studied. Results showed that the rolled composite with 30% deformation has a density of 8.28 g/cm3, a hardness of 1060 MPa (HB), an ultimate tensile strength of 288 MPa, an electrical resistivity of 7.0 ×10-8 Ω·m and a friction coefficient of 0.17.

关键词： Cu-Ti3SiC2 composite powder metallurgy electro-friction material

Universal properties of relaxation and diffusion in condensed matter

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Chinese Physics B 2017年第1期26卷 70-85页

作者： K L ngai State Key Laboratory of Metastable Materials Science and Technology. Yanshan University Qinhuangdao 066004 China

By and large the research communities today are not fully aware of the remarkable universality in the dynamic properties of many-body relaxation/diffusion processes manifested in experiments and simulations on condensed matter with diverse chemical compositions and physical structures. I shall demonstrate the universality first from the dynamic processes in glass-forming systems. This is reinforced by strikingly similar properties of different processes in contrasting interacting systems all having nothing to do with glass transition. The examples given here include glass-forming systems of diverse chemical compositions and physical structures, conductivity relaxation of ionic conductors（liquid, glassy, and crystalline）,translation and orientation ordered phase of rigid molecule, and polymer chain dynamics. Universality is also found in the change of dynamics when dimension is reduced to nanometer size in widely different systems. The remarkable universality indicates that many-body relaxation/diffusion is governed by fundamental physics to be unveiled. One candidate is classical chaos on which the coupling model is based, Universal properties predicted by this model are in accord with diverse experiments and simulations.

关键词： many-body relaxation/diffusion universal dynamics coupling model classical chaos

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掠夺性放贷应用程序加剧网络诈骗

商业周刊（中文版） 2024年第4期 16-18页

作者： Catherine ngai Fathiya Dahrul Pathom Sangwongwanich Shruti Mahajan 赵萌萌(译) 不详

●基于贷款应用程序的骗局愈发猖獗,而这些犯罪行动背后的幕后黑手正在适应防范措施麻烦往往从社交媒体广告开始。比如Facebook或Instagram上的那些广告:20分钟内即可获得500美元的个人贷款。无需任何文件,只要下载这个应用程序。潜在... 详细信息

●基于贷款应用程序的骗局愈发猖獗,而这些犯罪行动背后的幕后黑手正在适应防范措施麻烦往往从社交媒体广告开始。比如Facebook或Instagram上的那些广告:20分钟内即可获得500美元的个人贷款。无需任何文件,只要下载这个应用程序。潜在的借款人照做之后,他们就会交出手机通讯录和相册的访问权限。第二天,他们的朋友、家人和雇主就会收到电子邮件,称受害者指认他们为担保人,他们需要立即支付一大笔钱。

关键词：应用程序网络诈骗电子邮件访问权限手机通讯录 Facebook 借款人个人贷款

A novel recombinant,VPAC2-selective agonist enhancing insulin release and glucose disposal

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Acta Pharmacologica Sinica 2007年第4期28卷 526-533页

作者： ngai-lik TAM Bio-engineering Institute of Ji-nan University

Aim:To obtain the recombinant,VPAC2-selective ( VPAC2:type 3 receptor ofpituitary adenylate cyclase activating polypeptide which shared by vasoactiveintestinal peptide) agonist with effects on glucose disposal by intein-mediated,single column ***:A gene encoding 32-amino acid peptidenamed rMBAY was designed and synthesized and cloned into Escherichia coliexpression vector,pKYB (NEB,USA).The recombinant vector was transferredinto E coli ER2566 strain and the target protein was overexpressed as a fusion tothe N-terminus of a self-cleavable affinity *** the fusion protein was puri-fled by chitin-affinity chromatography,the self-cleavage activity of the intein wasinduced by β-mercaptoethanol and the target peptide,rMBAY,was released fromthe chitin-bound intein ***:Approximately 53 mg rMBAY with the purityover 95% was obtained by single column purification from 1 L induced culturefermented in 5 L *** results of the competitive binding assay andcAMP accumulation assay indicated that the recombinant rMBAY had specialbinding selectivity and potency for *** recombinant peptide,rMBAY,enhanced insulin release and decreased the plasma glucose level after intraperito-neal injection (50 ng/kg) with a high concentration of glucose (1.8 mmol/kg) in theNIH ***:An efficient production procedure of a recombinant VPAC2-selective agonist with corresponding effects on glucose disposal was established.

关键词： intein recombinant VPAC2 agonist insulin

Adaptive quantile regression with precise risk bounds

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Science China Mathematics 2017年第5期60卷 875-896页

作者： TIAN MaoZai CHAN ngai Hang School of Statistics Lanzhou University of Finance and Economics School of Statistics and Information Xinjiang University of Finance and Economics Center for Applied Statistics School of StatisticsRenmin University of China Department of Statistics The Chinese University of Hong Kong

An adaptive local smoothing method for nonpaxametric conditional quantile regression models is considered in this paper. Theoretical properties of the procedure are examined. The proposed method is fully adaptive in the sense that no prior information about the structure of the model is assumed. The fully adaptive feature not only allows varying bandwidths to accommodate jumps or instantaneous slope changes, but also al- lows the algorithm to be spatially adaptive. Under general conditions, precise risk bounds for homogeneous and heterogeneous cases of the underlying conditional quantile curves are established. An automatic selection algo- rithm for locally adaptive bandwidths is also given, which is applicable to higher dimensional cases. Simulation studies and data analysis confirm that the proposed methodology works well.

关键词： adaptive smoothing automatic bandwidths conditional quantile risk bounds robustness