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Nearest Neighb.r Sampling of Point Sets Using Rays

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1131-1174页

作者： Liangchen Liu Louis Ly Colin b.Macdonald Richard Tsai Department of Mathematics The University of Texas at Austin2515 SpeedwayAustinTX 78712USA Oden Institute for Computational Engineering and Sciences The University of Texas at Austin201 E24th StAustinTX 78712USA Department of Mathematics University of British Columbia1984 Mathematics RdVancouverBCV6T1Z2Canada

We propose a new framework for the sampling,compression,and analysis of distrib.tions of point sets and other geometric ob.ects emb.dded in Euclidean *** approach involves constructing a tensor called the RaySense sketch,which captures nearest neighb.rs from the underlying geometry of points along a set of *** explore various operations that can b. performed on the RaySense sketch,leading to different properties and potential *** information ab.ut the data set can b. extracted from the sketch,independent of the ray *** integrals on point sets can b. efficiently computed using the *** also present several examples illustrating applications of the proposed strategy in practical scenarios.

关键词： Point clouds Sampling Classification Registration Deep learning Voronoi cell analysis

Fat deposition and partitioning for meat production in cattle and sheep

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Animal Nutrition 2024年第2期17卷 376-386页

作者： Shimin Liu Yanyan Yang Hailing Luo Wenjie Pang Graeme b.Martin The UWA Institute of Agriculture The University of Western Australia Institute of Animal Husb.ndry of Inner Mongolia Academy of Agricultural and Animal Husb.ndry Sciences College of Animal Science and Technology of China Agricultural University Resonance Health Burswood

In markets for b.ef and sheep meat, an appropriate level of intramuscular fat(IMF) is highly desirab.e for meat-eating quality, b.t strategies to improve it usually lead to an undesirab.e excess in carcase fat,presenting a major challenge to livestock producers. To solve this prob.em, we need to understand the partitioning of fat among the major fat depots: IMF, sub.utaneous fat(SCF) and visceral fat(VF). In most genotypes of cattle and sheep, the rate of accretion is lower for IMF than for SCF and VF, so genetic selection for a high level of IMF, or the use of an increased dietary energy supply to promote IMF deposition, will increase overall fatness and feed costs. On the other hand, feeding postnatal calves with excessive concentrates promotes IMF deposition, so a nutritional strategy is feasib.e. With genetic strategies, several prob.ems arise: 1) positive genetic correlations b.tween IMF, SCF and VF differ among genotypes in b.th cattle and sheep; 2) genotypes appear to have specific, characteristic rates of accretion of IMF during periods of growth and fattening; 3) most b.eeds of cattle and sheep naturally produce meat with relatively low levels of IMF, b.t IMF does vary sub.tantially among individuals and b.eeds so progress is possib.e through accurate measurement of IMF. Therefore, an essential prerequisite for selection will b. knowledge of the genetic correlations and fat accretion rates for each genotype. Currently,selection for IMF is b.sed on existing technology that directly measures IMF in the progeny or sib.ings, or estimates IMF in live animals. New technology is needed to permit the simultaneous measurement of SCF and IMF in the field, thus opening up the possib.lity of accurate selection, particularly for fat partitioning in live animals. Specifically, there would b. great value in detecting individuals with an IMF advantage at an early age so the generation interval could b. shortened and genetic gain accelerated. Genetic gain would also b. grea

关键词： Fat depot Fat partition Intramuscular fat Feed efficiency b.vine Ovine

b.opolymer stab.lization of clayey soil

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2801-2812页

作者： Mahdieh Azimi Amin Soltani Mehdi Mirzab.b.ei Mark b.Jaksa Nanjappa Ashwath College of Engineering and Aviation School of Engineering and TechnologyCQUniversityMelbourneVIC 3000Australia Institute of Innovation Science and Sustainabilityand Future Regions Research CenterFederation UniversityChurchillVIC 3842Australia Department of Infrastructure Engineering Faculty of Engineering and Information TechnologyThe University of MelbourneParkvilleVIC 3010Australia School of Architecture and Civil Engineering The University of AdelaideAdelaideSA 5005Australia School of Health Medical and Applied SciencesCQUniversityRockhamptonQLD 4701Australia

This study investigates the efficacy of sodium alginate(SA),xanthan gum(XG),guar gum(GG)and chitosan(CS)d each applied at five different solid b.opolymer-to-water mass ratios(or dosages)and cured for 7 d and 28 d d on the unconfined compressive strength(UCS)performance of a high plasticity clayey ***,on identifying the optimum b.opolymer-treatment scenarios,their performance was compared against conventional stab.lization using hydrated *** a given curing time,the UCS for all b.opolymers followed a riseefall trend with increasing b.opolymer dosage,peaking at an optimum dosage and then sub.equently decreasing,such that all b.opolymer-stab.lized samples mob.lized higher UCS values compared to the unamended *** optimum dosage was found to b. 1.5%for SA,XG and CS,while a notab.y lower dosage of 0.5%was deemed optimum for ***,for a given b.opolymer type and dosage,increasing the curing time from 7 d to 28 d further enhanced the UCS,with the achieved improvements b.ing generally more pronounced for XG-and CS-treated *** of the investigated b.opolymers was ab.e to produce UCS improvements equivalent to those ob.ained b. the 28-d soilelime samples;however,the optimum XG,GG and CS dosages,particularly after 28 d of curing,were easily ab.e to replicate 7-d lime stab.lization outcomes achieved with as high as twice the soil’s lime ***,the fundamental principles of clay chemistry,in conjunction with the soil mechanics framework,were employed to identify and discuss the clayeb.opolymer stab.lization mechanisms.

关键词： Soil stab.lization High plasticity clay b.opolymer dosage Hydrated lime Curing time Unconfined compressive strength(UCS)

文化生产的平台化:对权变性文化商品的理论分析

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中国电视 2024年第7期 100-112页

作者： [加拿大]大卫·b.尼伯格 [荷兰]托马斯·波尔章宏(译) 胡颢琛(译) 多伦多大学士嘉堡分校阿姆斯特丹大学浙江大学传媒与国际文化学院浙江大学数字沟通研究中心浙江大学国际传播研究中心上海出版印刷高等专科学校复旦大学新闻学院

在线平台经济及其基础设施在网络空间不断扩展,它们对文化内容的生产、发行与流通产生了深远的影响。平台化意味着大型平台公司主导的复杂多边平台配置取代了双边市场结构。文化内容生产者必须不断应对看似偶然的平台治理变化,这些变化... 详细信息

在线平台经济及其基础设施在网络空间不断扩展,它们对文化内容的生产、发行与流通产生了深远的影响。平台化意味着大型平台公司主导的复杂多边平台配置取代了双边市场结构。文化内容生产者必须不断应对看似偶然的平台治理变化,这些变化涵盖了从内容策展到定价策略等各个层面。同时,这些生产者被新的平台服务和基础设施变化吸引,在这个过程中,文化商品从根本上变得具有“权变性”,即在设计上越来越模块化,并根据数据化的用户反馈不断重新加工和包装。为进一步深入思考文化产业的政治经济学在平台化趋势下所发生的变化,在商业研究、政治经济学和软件研究三个领域之间展开跨学科的批判性对话显得至关重要。

关键词：文化生产多边市场平台化政治经济学软件研究

A Review on Technologies for the Use of CO2 as a Working Fluid in Refrigeration and Power Cycles

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Energy and Power Engineering 2024年第6期16卷 217-256页

作者： Orelien T. b.upda Hyacinthe D. Tessemo Isidore b. Nkounda Fongang Francklin G. Nyami Frederic Lontsi Thomas Djiako Lab.ratory of Energy Higher National Polytechnic School of Douala University of Douala Douala Cameroon Institut Ucac-Icam Douala Cameroon Department of Energy and Mechanical Engineering ISTA-IUG University of Ngaoundere Ngaoundere Cameroon

The use of carb.n dioxide as a working fluid has b.en the sub.ect of extensive studies in recent years, particularly in the field of refrigeration where it is at the heart of research to replace CFC and HCFC. Its thermodynamic properties make it a fluid of choice in the efficient use of energy at low and medium temperatures in engine cycles. However, the performance of transcritical CO2 cycles weakens under high temperature and pressure conditions, especially in refrigeration systems;On the other hand, this disadvantage b.comes rather interesting in engine cycles where CO2 can b. used as an alternative to the organic working fluid in small and medium-sized electrical systems for low quality or waste heat sources. In order to improve the performance of systems operating with CO2 in the field of refrigeration and electricity production, research has made it possib.e to develop several concepts, of which this article deals with a review of the state of the art, followed b. analyzes in-depth and critical of the various developments to the most recent modifications in these fields. Detailed discussions on the performance and technical characteristics of the different evolutions are also highlighted as well as the factors affecting the overall performance of the systems studied. Finally, perspectives on the future development of the use of CO2 in these different cycles are presented.

关键词： Refrigeration Cycle Power Cycle System Performance Transcritical CO2 Cycles Working Fluid

Near-Surface Soil Chemical Properties as Affected b. Cover Crops Over Time in the Lower Mississippi River Valley

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Agricultural Sciences 2024年第9期15卷 1035-1056页

作者： Cooper Fanning Kristofor R. b.ye Michael b. Daniels Trenton L. Rob.rts Samuel Fernandes Lisa S. Wood Department of Crop Soil and Environmental Sciences University of Arkansas Fayetteville USA

Typical row-crop agricultural practices can potentially b. harmful to soil health and future sustainab.lity. The use of cover crops (CC) as a mechanism to improve soil health on a wide scale remains underutilized. Soil health remains a major concern for the sustainab.lity of agricultural productivity, therefore, research into CC implementation as a mean to preserve or improve soil health is warranted. The ob.ective of this study was to evaluate the effects of CC on the soils in the eastern Arkansas portion of the Lower Mississippi River Valley (LMRV) over time for various chemical soil parameters, including pH, soil organic matter (SOM), soil elemental contents (i.e., P, K, Ca, Mg, S, Na, Fe, Mn, Zn, Cu, and b., soil respiration, and a generalized soil health score index. Soil pH decreased over time under b.th CC and no-cover-crop (NCC) treatments, b. −0.3 and −0.2, respectively. Soil OM decreased over time under NCC b. −0.1%, b.t did not differ b.tween CC treatments. Soil N availab.lity decreased over time under NCC (−22.6 kg·ha−1), b.t did not change over time under CC. Soil respiration decreased over time under b.th CC and NCC, b. −76.1 mg·L−1 and −77.3 mg·L−1, respectively, though there was no effect of CC treatment. The Haney soil health score index decreased under CC (−7.0) and NCC (−6.8) without an effect from CC treatment. Results of the study place emphasis on the temporal nature of soil health as influenced b. cover crops and their potential to improve soil health.

关键词： Arkansas Cover Crops Soil Properties Soil Organic Matter Soil Health Score

Mitigating Urb.n Heat Island Effects: A Review of Innovative Pavement Technologies and Integrated Solutions

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Structural Durab.lity & Health Monitoring 2024年第5期18卷 525-551页

作者： S.F.Ismael A.H.Alias N.A.Haron b.b.Zaidan Ab.ulrahman M.Ab.ulghani Department of Civil Engineering Faculty of EngineeringUniversiti Putra MalaysiaSerdang43400Malaysia Central Region Heavy Civil DivisionGranite ConstructionWoodlandsTexas77381USA SP Jain School of Glob.l Management LidcombeSydneyNSW2141Australia Department of Communication Technology and Network Faculty of Computer Science and Information TechnologyUniversiti Putra MalaysiaSerdang43400Malaysia

In this review paper,we present a thorough investigation into the role of pavement technologies in advancing urb.n *** analysis traverses the historical evolution of these technologies,meticulously evaluating their socio-economic and environmental impacts,with a particular emphasis on their role in mitigating the urb.n heat island *** evaluation of pavement types and variab.es inﬂuencing pavement performance to b. used in the multi-criteria decision-making(MCDM)framework to choose the optimal pavement application are at the heart of our *** serves to assess a spectrum of pavement options,revealing insights into the most effective and sustainab.e *** highlighting b.th the existing challenges and potential innovative solutions within theﬁeld,this paper aims to offer a directional compass for future urb.n planning and infrastructural *** review not only synthesizes the current state of knowledge b.t also aims to chart a course for future exploration,emphasizing the critical need for innovative and environmentally sensitive pavement tech-nologies in the creation of resilient and sustainab.e urb.n environments.

关键词： Pavement sustainab.lity urb.n heat island environmental impact of pavements innovative pavement solutions economic and social implications sustainab.e development in urb.n areas

Dynamics of a two-group model for assessing the impacts of pre-exposure prophylaxis,testing and risk b.haviour change on the spread and control of HIV/AIDS in an MSM population

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Infectious Disease Modelling 2024年第1期9卷 103-127页

作者： Queen Tollett Salman Safdar Ab.a b.Gumel School of Mathematical and Statistical Sciences Arizona State UniversityTempeAZ85287USA Department of Mathematics University of KarachiUniversity Road75270Pakistan Department of Mathematics University of MarylandCollege ParkMD20742USA Department of Mathematics and Applied Mathematics University of PretoriaPretoria0002South Africa

Although much progress has b.en made in reducing the pub.ic health b.rden of the human immunodeficiency virus(HIV),which causes acquired immunodeficiency syndrome(AIDS),since its emergence in the 1980s(largely due to the large-scale use and availab.lity of potent antiviral therapy,improved diagnostic and intervention and mitigation measures),HIV remains an important pub.ic health challenge glob.lly,including in the United *** study is b.sed on the use of mathematical modeling approaches to assess the population-level impact of pre-exposure prophylaxis(PrEP),voluntary testing(to detect undetected HIV-infected individuals),and changes in human b.havior(with respect to risk structure),on the spread and control of HIV/AIDS in an MSM(men-who-have sex-with-men)***,a novel two-group mathematical model,which stratifies the total MSM population b.sed on risk(low or high)of acquisition of HIV infection,is *** model undergoes a PrEP-induced b.ckward b.furcation when the control reproduction numb.r of the model is less than one if the efficacy of PrEP to prevent a high-risk susceptib.e MSM individual from acquiring HIV infection is not perfect(the consequence of which is that,while necessary,having the reproduction numb.r of the model less than one is no longer sufficient for the elimination of the disease in the MSM population).For the case where the efficacy of PrEP is perfect,this study shows that the disease-free equilib.ium of the two-group model is glob.lly-asymptotically stab.e when the associated control reproduction numb.r of the model is less than *** sensitivity analysis was carried out to identify the main parameters of the model that have the highest influence on the value of the control reproduction numb.r of the model(thereb.,having the highest influence on the disease b.rden in the MSM population).Numerical simulations of the model,using a plausib.e range of parameter values,show that if half of the MSM population co

关键词： HIV/AIDS MS MHigh(low)-risk groups PrEP b.havior change Antiviral treatment Control reproduction numb.r

Smart mid-infrared metasurface microspectrometer gas sensing system

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Microsystems & Nanoengineering 2024年第3期10卷 273-281页

作者： Jiajun Meng Sivacarendran b.lendhran Ylias Sab.i Suresh K.b.argava Kenneth b.Crozier School of Physics University of MelbourneVictoriaAustralia Australian Research Council(ARC)Centre of Excellence for Transformative Meta-Optical Systems(TMOS) University of MelbourneVictoriaAustralia Centre for Advanced Materials&Industrial Chemistry(CAMIC) STEM collegeRMIT UniversityVictoriaAustralia Department of Electrical and Electronic Engineering University of MelbourneVictoriaAustralia

Smart,low-cost and portab.e gas sensors are highly desired due to the importance of air quality monitoring for environmental and defense-related ***,electrochemical and nondispersive infrared(IR)gas sensors are designed to detect a single specific *** IR spectroscopy-b.sed sensors provide superior performance,their deployment is limited due to their large size and high *** this study,a smart,low-cost,multigas sensing system is demonstrated consisting of a mid-infrared microspectrometer and a machine learning *** microspectrometer is a metasurface filter array integrated with a commercial IR camera that is consumab.e-free,compact(~1 cm^(3))and lightweight(~1 g).The machine learning algorithm is trained to analyze the data from the microspectrometer and predict the gases *** system detects the greenhouse gases carb.n dioxide and methane at concentrations ranging from 10 to 100%with 100%*** also detects hazardous gases at low concentrations with an accuracy of 98.4%.Ammonia can b. detected at a concentration of 100 ***,methyl-ethyl-ketone can b. detected at its permissib.e exposure limit(200 ppm);this concentration is considered low and *** study demonstrates the viab.lity of using machine learning with IR spectroscopy to provide a smart and low-cost multigas sensing platform.

关键词： Smart gases system