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Segment routing for traffic engineering and effective recovery in low-earth orbit satellite constellations

digital Communications and Networks 2024年第3期10卷 706-715页

作者： Shengyu Zhang Xiaoqian Li Kwan lawrence Yeung department of Electrical and Electronic Engineering The University of Hong KongHKSARChina National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of ChinaChengduSichuan611731China

Low-Earth Orbit Satellite Constellations(LEO-SCs)provide global,high-speed,and low latency Internet access services,which bridges the digital divide in the remote *** inter-satellite links are not supported in initial deployment(*** Starlink),the communication between satellites is based on ground stations with radio frequency *** to the rapid movement of satellites,this hybrid topology of LEO-SCs and ground stations is time-varying,which imposes a major challenge to uninterrupted service provisioning and network *** this paper,we focus on solving two notable problems in such a ground station-assisted LEO-SC topology,i.e.,traffic engineering and fast reroute,to guarantee that the packets are forwarded in a balanced and uninterrupted ***,we employ segment routing to support the arbitrary path routing in *** solve the traffic engineering problem,we proposed two source routings with traffic splitting algorithms,delay-Bounded Traffic Splitting(dBTS)and dBTS+,where dBTS equally splits a flow and dBTS+favors shorter ***-lation results show that dBTS+can achieve about 30%lower maximum satellite load at the cost of about 10%more *** guarantee the fast recovery of failures,two fast reroute mechanisms,Loop-Free Alternate(LFA)and LFA+,are studied,where LFA pre-computes an alternate next-hop as a backup while LFA+finds a 2-segment backup *** show that LFA+can increase the percentage of protection coverage by about 15%.

关键词： Fast reroute Low-earth orbit satellite constellation Segment routing Traffic engineering Traffic splitting

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Carbene chemistry for unnatural biosynthesis

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Science China(Life Sciences) 2024年第1期67卷 204-207页

作者： Jing Huang Jay d.Keasling department of Chemical and Biomolecular Engineering University of CaliforniaBerkeley 94720USA Joint BioEnergy Institute Lawrence Berkeley National LaboratoryEmeryville 94608USA Biological Systems and Engineering division Lawrence Berkeley National LaboratoryBerkeley 94720USA Novo Nordisk Foundation Center for Biosustainability Technical University of DenmarkKongens Lyngby 2800Denmark department of Bioengineering University of CaliforniaBerkeley 94720USA Synthetic Biochemistry Center Institute for Synthetic BiologyShenzhen Institutes for Advanced TechnologiesShenzhen 518055China

Previously,chemists working in synthesis were jealous of biologists since the enzymes found in nature usually exhibited great catalytic properties(e.g.,high catalytic efficiency,excellent selectivity such as substrate selectivity,regioselectivity and stereoselectivity).However,biological systems lack many counterparts of reactions widely used in chemical synthesis.

关键词： synthesis selectivity catalytic

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Projective Hilbert modules and sequential approximations

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Science China Mathematics 2024年

作者： lawrence G.Brown Huaxin Lin department of Mathematics Purdue University department of Mathematics East China Normal University department of Mathematics University of Oregon

We show that when A is a separable C*-algebra, every countably generated Hilbert A-module is projective(with bounded module maps as morphisms). We also study the approximate extensions of bounded module maps. In the case where A is a σ-unital simple C*-algebra with strict comparison, and every strictly positive lower semicontinuous affine function on quasitraces can be realized as the rank of an element in the Cuntz semigroup, we show that the Cuntz semigroup is equivalent to unitarily equivalent classes of countably generated Hilbert A-modules if and only if A has stable rank one.

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Failure mechanism and simulation for long run-out of the catastrophic rock landslide in the Shanyang Vanadium Mine,China

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Journal of Mountain Science 2024年第9期21卷 2905-2917页

作者： LIU Yinpeng Mumtaz HAIdER david-darnor lawrence LI Tonglu SHEN Wei LI Ping College of Geological Engineering and Geomatics Chang’an UniversityXi’an 710054China Observation and Research Station of Water Cycle and Geological Environment for the Chinese Loess Plateau Ministry of EducationZhengning 745399China

On 12th August 2015,a massive rapid long run-out rock landslide occurred in the Shanyang Vanadium Mine in Shaanxi Province,China,which claimed the lives of 65 *** heavy rainfalls,earthquakes,and mining blasts were recorded before the ***,the failure mechanism and the cause of the long run-out movement are always in *** this paper,we conducted a detailed field investigation,laboratory tests,block theory analysis,and numerical simulation to investigate the failure and long run-out mechanisms of the *** field investigation results show that the source material of the rock landslide is a huge dolomite wedge block bedding on siliceous shale *** compression tests indicate that the uniaxial compression strength of the intact dolomite is 130-140MPa and the dolomite shows a brittle failure *** to the progressive downward erosion of the gully,the dolomite rock bridge at the slope toe became *** the compression stress in the dolomite bridge increased to surpass its strength,the brittle failure of the bridge *** huge potential energy was released following the disintegration of the landslide,which led to the high acceleration of this rock *** 3d discrete element simulation results suggest that the low intergranular friction contributes to the long run-out movement of this rock landslide.

关键词： Rock landslide Gully erosion Long run-out Wedge block discrete element method

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dual Instinct and Structural Theories: dSM-5-TR

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Open Journal of Psychiatry 2024年第4期14卷 374-379页

作者： lawrence Greenman Hudson Valley Health Care System Poughkeepsie NY USA

The genetic based dual Instinct Theory is determined by evolutionary history. Aggression is required for survival and sex for propagation of species. Aggressive and sexual drive derivatives with their corresponding defence mechanisms are combined with biologically based stages of infant/child development and the functional entity of Structural Theory. This model of human nature is the applied to the diagnostic categories of dSM-5-TR. Objectives: To follow the innate dual Instinct Theory from life to death and through Artificial Intelligence;connect it with biological stages of development of the Structural Theory and illustrate its manifestations in dSM-5-TR classifications. Method: Review of selected published literature. Applying the principle of focus and cognition of informed clinical observation of innate drive derivatives in conjunction with The Structural Theory. Both theories are functional entities with no structures involved. Sigmund Freud’s biologically based stages of development;oral, anal, genital pubic, adult, and geriatric along with a variety of unconscious, automatic, and persistent defense mechanisms are selectively folded into diagnosis listed in the manual.

关键词： dual Instincts Structural Theory Stages of development drive derivatives Mechanisms of defense

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Faith and Belief in Autism in Cote d’Ivoire: About Judith, God’s Strange Gift

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Case Reports in Clinical Medicine 2024年第1期13卷 1-11页

作者： Anna-Corinne Bissouma lawrence Yapi Center Marguerite Té Bonle National Institut of Public Health Abidjan Cote d’Ivoire Psychology department Felix Houphouet-Boigny University Abidjan Cote d’Ivoire

Faced with autism, motherhood and parenthood are turned upside down in many ways. Coping with stress and mental health problems, continuing to assume a rewarding parental role and finding suitable care are the trials and tribulations that mark out the journey of African parents. Faith and belief have been described as providing meaning and coping mechanisms in the frightening ordeal of disability. An encounter with a young girl and her parents provided an opportunity to analyse the mother’s experience and the impact of beliefs and discourses on her commitment to care. Based on this clinical story, we discuss the place of other-actors (parents and carers) and the Other-God in relation to the psychopathological dynamics of the mother.

关键词： Maternal Autism Belief Other Cote d’Ivoire

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Spatial Heterogeneity Modeling Using Machine Learning Based on a Hybrid of Random Forest and Convolutional Neural Network (CNN)

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Journal of data Analysis and Information Processing 2024年第3期12卷 319-347页

作者： Amadou Kindy Barry Anthony Waititu Gichuhi lawrence Nderu department of Mathematics Pan African University Institute for Basic Sciences Technology and Innovation (PAUISTI) Nairobi Kenya department of Statistics and Actuarial Science Jomo Kenyatta University of Agriculture and Technology Nairobi Kenya department of Computing School and Information Technology (SCIT) Jomo Kenyatta University of Agriculture and Technology (JKUAT) Nairobi Kenya

Spatial heterogeneity refers to the variation or differences in characteristics or features across different locations or areas in space. Spatial data refers to information that explicitly or indirectly belongs to a particular geographic region or location, also known as geo-spatial data or geographic information. Focusing on spatial heterogeneity, we present a hybrid machine learning model combining two competitive algorithms: the Random Forest Regressor and CNN. The model is fine-tuned using cross validation for hyper-parameter adjustment and performance evaluation, ensuring robustness and generalization. Our approach integrates Global Moran’s I for examining global autocorrelation, and local Moran’s I for assessing local spatial autocorrelation in the residuals. To validate our approach, we implemented the hybrid model on a real-world dataset and compared its performance with that of the traditional machine learning models. Results indicate superior performance with an R-squared of 0.90, outperforming RF 0.84 and CNN 0.74. This study contributed to a detailed understanding of spatial variations in data considering the geographical information (Longitude & Latitude) present in the dataset. Our results, also assessed using the Root Mean Squared Error (RMSE), indicated that the hybrid yielded lower errors, showing a deviation of 53.65% from the RF model and 63.24% from the CNN model. Additionally, the global Moran’s I index was observed to be 0.10. This study underscores that the hybrid was able to predict correctly the house prices both in clusters and in dispersed areas.

关键词： Spatial Heterogeneity Spatial data Feature Selection Standardization Machine Learning Models Hybrid Models

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计划行为理论视角下高校外语教师整合非正式数字化英语学习意愿研究

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外语电化教学 2024年第2期 79-84页

作者：刘广祥王永亮 ZHANG Jun lawrence 香港中文大学中国香港999077 华北水利水电大学河南省郑州市450046 奥克兰大学奥克兰92019

文章以210名国内高校外语教师为研究对象,在计划行为理论的基础上结合结构方程模型和半结构化访谈的研究方法,探讨了教师对将非正式数字化英语学习整合到教学实践中的意愿。研究发现:(1)态度和知觉行为控制可以直接影响高校教师对课程... 详细信息

文章以210名国内高校外语教师为研究对象,在计划行为理论的基础上结合结构方程模型和半结构化访谈的研究方法,探讨了教师对将非正式数字化英语学习整合到教学实践中的意愿。研究发现:(1)态度和知觉行为控制可以直接影响高校教师对课程整合非正式数字化英语学习的行为意愿,而主观规范则不能对该意愿起显著的预测作用;(2)高校教师对非正式数字化英语学习的态度受到其数字素养水平的显著影响;(3)对知觉行为控制的评估受到外部信念及特定教学环境等多种主客观条件的影响。研究结果有助于为国内高校外语教师专业发展和课外数字化英语教学议程设置提供参考。

关键词：非正式数字化英语学习计划行为理论计算机辅助语言学习

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The Protocol of Ultrasonic Backscatter Measurements of Musculoskeletal Properties

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Phenomics 2024年第1期4卷 72-80页

作者： dongsheng Bi Lingwei Shi Boyi Li Ying Li Chengcheng Liu lawrence HLe Jingchun Luo Sijia Wang dean Ta Center for Biomedical Engineering School of InformationScience and TechnologyFudan University2005 SonghuRoadYangpu DistrictShanghai 200438China Academy for Engineering and Technology Fudan UniversityShanghai 200433China department of Radiology and diagnostic Imaging University of AlbertaEdmonton T6G2B7Canada Human Phenome Institute Fudan UniversityShanghai 201203China Shanghai Institute of Nutrition and Health Chinese Academyof SciencesShanghai 200031China

This study aims to introduce the protocol for ultrasonic backscatter measurements of musculoskeletal properties based on a novel ultrasonic backscatter bone diagnostic(UBBd)***-energy X-ray absorptiometry(dXA)can be adopted to measure bone mineral density(BMd)in the hip,spine,legs and the whole *** muscle and fat mass in the legs and the whole body can be also calculated by dXA body composition *** on the proposed protocol for backscatter measurements by UBBd,ultrasonic backscatter signals can be measured in vivo,deriving three backscatter parameters[apparent integral backscatter(AIB),backscatter signal peak amplitude(BSPA)and the corresponding arrival time(BSPT)].AIB may provide important diagnostic information about bone *** and BSPT may be important indicators of muscle and fat *** standardized backscatter measurement protocol of the UBBd instrument may have the potential to evaluate musculoskeletal characteristics,providing help for promoting the application of the backscatter technique in the clinical diagnosis of musculoskeletal disorders(MSds),such as osteoporosis and muscular atrophy.

关键词： Ultrasonic backscatter Musculoskeletal disorders Bone mineral density Muscle mass Fat mass

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The Value of Rural Access Roads: The Case Study of Chepyuk and Mitira Wards in Bungoma and Kirinyaga Counties

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Open Journal of Applied Sciences 2024年第8期14卷 2249-2266页

作者： Alfred Eshitera lawrence Esho Casty Gataaka Njoroge Yvone Balan department of Spatial Planning and design Technical University of Kenya Nairobi Kenya digiReg Nairobi Kenya

In this paper we assess the impact of road network on rural regions development using a case study of Chepyuk and Mitira wards. The two case study areas were selected owing to their comparable agro ecological conditions but different political orientation. The wards have identical agro economic activities due to their similarity in climatic and ecological conditions. Household incomes earned from agricultural enterprises and bid rent per unit area of land are used as indicators of development. The condition of road network is used as an indicator of accessing the rural regions in various seasons of the year. The study provides evidence of the economic advantages associated with better market access, primarily due to the good road infrastructure in Mitira compared to Chepyuk. The good road condition is advantageous to Mitira ward residents allowing them to access other markets hence improving the farm gate value of their products. On the other hand, the prices for Chepyuk products are cheap due to constrained market access necessitated by the poor road condition. For instance, the average price of a liter of milk in Chepyuk ward is Kshs.36.65 compared to Mitira where it goes at Kh.55.08. It therefore implies in Chepyuk milk has to be sold at lower price since access to alternative markets is constrained by poor road condition. The disparity in the road network quality has been occasioned by investment policy by both colonial and consecutive post-independence governments which have given preference to the region where Mitira region is located. This is against the constitutional requirement which proposes an equalization fund for infrastructure development to regions lagging behind in terms of development.

关键词： Rural Areas Regional development Road Network Kenya

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