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Modelling the brittle rock failure by the quaternion-based bonded-particle model in DeM

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Rock Mechanics Bulletin

Rock Mechanics Bulletin 2024年第2期3卷 87-95页

作者： Tao Zhao Philip e.F.Collins Department of Civil and environmental engineering Brunel University LondonLondonUB83PHUnited Kingdom

This paper presents an investigation of brittle rock failure by the quaternion-based bonded-particle model in discrete element method(DeM).Unlike traditional approaches that utilize euler angles or rotation matrices,this model employs unit quaternions to represent the spatial rotations of *** method simplifies the rep-resentation of 3D rotations,providing a more intuitive framework for modelling complex interactions in granular *** numerical model was validated by the uniaxial compression tests on rock,with good agreement with well-documented experimental data in terms of the rock uniaxial compression strength(UCS)and failure *** loading,the rock sample demonstrated a linear-elastic response at an axial strain of smaller than 0.45%.However,as internal bond breakage accumulated,this linear relationship weakened,and the stress-strain curve began to deviate from its initial linear *** bond breakage and the overall deformation of the rock were primarily controlled by the shear bonding *** UCS was achieved at an axial strain of 0.625%,at which point the internal shear bonding force chains were predominantly aligned *** brittle failure occurred when the internal damage of solids nucleated to form an interconnected failure plane,accompanied by a sharp rise in the internal damage *** area of failure plane increased with the loading strain rate,gradually transforming the failure pattern from the local damage to a complete fragmentation.

关键词： Brittle failure Quaternion DeM bonded model Uniaxial compression test Rate dependent Internal damage

Current considerations for the surgical management of gallbladder adenomas

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World Journal of Gastrointestinal Surgery 2024年第6期16卷 1507-1512页

作者： efstathios T Pavlidis Ioannis N Galanis Theodoros e Pavlidis The Second Department of Propaedeutic Surgery Hippokration General HospitalSchool of MedicineAristotle University of ThessalonikiThessaloniki 54642Greece

Gallbladder adenomas are rare lesions(0.5%)associated with potential malignant transformation,particularly with gallbladder adenomas that are≥1 cm in *** detection and management are crucial for preventing lethal carcinoma *** polyps can often be distinguished from the more often nonneo-plastic cholesterol pseudopolyps(5%-10%),which are *** is the first-line tool for initial diagnosis and follow-up when *** question is whether cholecystectomy is always necessary for all *** manage-ment of gallbladder adenomas is determined according to the size of the tumor,the growth rate of the tumor,the patient’s symptoms and whether risk factors for malignancy are ***≥1 cm in size,an age>50 years and a familial history of gallbladder carcinoma are indications for immediate laparoscopic ***,ultrasound follow-up is *** adenomas 6-9 mm in size,the absence of≥2 mm growth at 6 months,one year,and two years,as well as an adenoma sizedexisting risk factors indicates that no further surveillance is ***,it would be preferable to individualize the management in doubtful *** interventional modalities for preserving the gallbladder need further evaluation,especially to determine the long-term outcomes.

关键词： Biliary diseases True neoplastic polyps Gallbladder adenomas Benign bi-liary tumors Gallbladder polyps extrahepatic biliary neoplasms

FGM-SPCL:Open-Set Recognition Network for Medical Images Based on Fine-Grained Data Mixture and Spatial Position Constraint Loss

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Chinese Journal of electronics 2024年第4期33卷 1023-1033页

作者： Ruru ZHANG Haihong e Lifei YUAN Yanhui WANG Lifei WANG Meina SONG School of Computer Science Beijing University of Posts and Telecommunications engineering Research Center of Information Networks Ministry of Education Hebei eye Hospital

The current intelligent auxiliary diagnosis models all follow the closed-set recognition setting. After the model is deployed online, the input data is often not completely controlled. Diagnosing an untrained disease as a known category would lead to serious medical malpractice. Therefore, realizing the open-set recognition is significant to the safe operation of the intelligent auxiliary diagnosis model. Currently, most open-set recognition models are studied for natural images, and it is very challenging to obtain clear and concise decision boundaries between known and unknown classes when applied to fine-grained medical images. We propose an open-set recognition network for medical images based on fine-grained data mixture and spatial position constraint loss(FGM-SPCL) in this *** the fine graininess of medical images and the diversity of unknown samples, we propose a fine-grained data mixture(FGM) method to simulate unknown data by performing a mixing operation on known data to expand the coverage of unknown data difficulty levels. In order to obtain a concise and clear decision boundary, we propose a spatial position constraint loss(SPCL) to control the position distribution of prototypes and samples in the feature space and maximize the distance between known classes and unknown classes. We validate on a private ophthalmic OCT dataset, and extensive experiments and analyses demonstrate that FGM-SPCL outperforms state-of-the-art models.

关键词： Analytical models Fine-grained image recognition Prototypes Aerospace electronics Spatial databases Robustness Data models

Global black soil distribution

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Frontiers of Agricultural Science and engineering 2024年第2期11卷 271-281页

作者： Yuxin TONG Marcos e.ANGeLINI Yusuf YIGINI Isabel LUOTTO Global Soil Partnership Land and Water DivisionFood and Agriculture Organization of the United NationsRome 00153Italy

Black soils, characterized by their thick, dark horizons enriched with organic matter, epitomize highly fertile soils. However, their fertility precipitates intense land use, engendering challenges such as soil erosion, nutrient depletion, pollution, compaction, salinization, and acidification. Notably, these soils are significant contributors to global greenhouse gas emissions, primarily due to substantial losses in soil organic carbon. Despite these challenges, black soils are pivotal for global food production. This paper delineates the implementation of digital soil mapping for the global cartography of black soils and human interference on these soils. Predominantly distributed in eastern europe, Central and eastern Asia, and North and South America, black soils cover an approximate area of 725 Mha, with the Russian Federation,Kazakhstan, and China collectively have over half of this area. Agriculturally,these soils underpin significant proportions of global crop yields, producing 66% of sunflower, 30% of wheat, and 26% of potato outputs. The organic carbon content in the upper 30 cm of these soils is estimated at 56 *** management of black soils is imperative for ensuring food security and addressing climate change on a global scale.

关键词： Black soils distribution map food security soil organic carbon

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The 2024 Compendium of Physical Activities and its expansion

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Journal of Sport and Health Science 2024年第1期13卷 1-2,F0003页

作者： Stephen D.Herrmann erik A.Willis Barbara e.Ainsworth Kansas Center for Metabolism and Obesity Research University of Kansas Medical CenterKansas CityKS 66160USA Center for Health Promotion and Disease Prevention University of North Carolina at Chapel HillChapel HillNC 27599USA School of exercise and Health Shanghai University of SportShanghai 200438China

First developed 30 years ago,the Compendium of Physical Activities(Compendium)was created to provide a standardized way of measuring and classifying specific physical activities(PAs),allowing researchers and health professionals to assess the energy expenditure and health benefits associated with different PA.1Since its inception,the Compendium has been widely utilized and recognized as a fundamental PA and health resource.

关键词： has utilized classify

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Implementation and evaluation of exercise is Medicine in primary care clinics within a large academic health system

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Family Medicine and Community Health 2024年第1期12卷 16-27页

作者： John Kevin Ong Dayao Caroline e L Duffy Amalia M Cristiano Gene'Rusty'Kallenberg Sarah e Linke University of California San Diego School of Medicine La JollaCaliforniaUSA Milken Institute of Public Health The George Washington UniversityWashingtonDistrict of ColumbiaUSA The University of Texas Medical Branch at Galveston School of Medicine GalvestonTexasUSA Scripps Family Medicine Residency Scripps Mercy Hospital Chula VistaChula VistaCaliforniaUSA Herbert Wertheim School of Public Health&Human Longevity Science University of California San DiegoLa JollaCaliforniaUSA Department of Family Medicine University of California San DiegoLa JollaCaliforniaUSA Omada Health San FranciscoCaliforniaUSA

Objective exercise is Medicine(eIM)is a global initiative encouraging healthcare providers to routinely assess and promote physical activity(PA)among *** objective of this study was to evaluate the feasibility,adoption,implementation and effectiveness of eIM from patient,clinician and healthcare staff perspectives using a combination of electronic health record(eHR),survey and interview *** This study used a combination of the Practical Robust Implementation and Sustainability Model(PRISM)and the Learning evaluation model to implement *** captured from the eHR,including Physical Activity Vital Sign(PAVS)scores,and data collected from qualitative surveys and interviews were used to evaluate the programme’s Reach,effectiveness,Adoption,Implementation,Maintenance(Re-AIM,which is embedded within PRISM)from provider,staff and patient *** Five primary care clinics within a large academic health *** A total of 24443 patients from all participating clinics had at least one PAVS score during the study period.A total of 17 clinicians completed surveys,and 4 clinicians,8 medical assistants and 9 patients completed *** Implementation fidelity metrics varied widely between components and across clinics but were generally consistent over time,indicating a high degree of programme *** was highest during the first 6 months of the COVID-19 pandemic when most visits were *** PAVS scores increased from 57.7(95%CI:56 to 59.4)to 95.2(95%CI:91.6 to 98.8)min per week at 6 months for patients not meeting PA guidelines at baseline and decreased from 253.84(95%CI:252 to 255.7)to 208.3(95%CI:204.2 to 212.4)min per week at 6 months for patients meeting PA guidelines at *** eIM implementation,clinician-estimated time spent discussing PA with patients increased for 35%of providers and stayed the same for 53%.Conclusion Overall,this study established eIM’s feasibility,adoption,implementation

关键词： routine qualitative completed

Comparisons of oxbow lake fish assemblages in relation to bigheaded carp establishment in the lower White River, Arkansas

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ecological Processes 2024年第1期13卷 188-205页

作者： Michael A.eggleton Cody J.Salzmann Joseph e.Kaiser Shannon C.F.Smith Department of Aquaculture and Fisheries University of Arkansas at Pine Bluff Arkansas Game and Fish Commission Virginia Institute of Marine Science

Background Since the late 1990s, bigheaded carps(largely silver carp [Hypophthalmichthys molitrix] but also bighead carp [H. nobilis]) have established throughout the lower Mississippi River basin. Using previously studied oxbow lakes in the lower White River basin, Arkansas, we compared current(2017, “post-carp” establishment) fish assemblages to historical(2002, “pre-carp” establishment) fish assemblages. Fish assemblages were comprehensively assessed using multiple gears, including boat electrofishing, mini-fyke nets, and experimental small-mesh gill *** T-tests suggested that fish assemblage indices of richness, diversity, evenness, and dominance were often greater(P e post-carp period as reflected by boat electrofishing and experimental gill nets. However, all indices were generally similar(P > 0.05) between the pre-carp and post-carp period with fish assemblages depicted using mini-fyke nets. Nonmetric multidimensional scaling analyses indicated that fish assemblages differed structurally between pre-carp and post-carp periods. Assemblage differences were linked to both small and large abundance changes for more than 20 species. Abundances of gizzard shad(Dorosoma cepedianum), emerald shiner(Notropis atherinoides), pugnose minnow(Opsopoeodus emiliae), crappies(Pomoxis spp.), bluegill(Lepomis macrochirus), orangespotted sunfish(L. humilis), and yellow bass(Morone mississippiensis) declined between the pre-carp and postcarp periods. Conversely, abundances of weed shiner(N. texanus), pallid shiner(Hybopsis amnis), longear sunfish(L. megalotis), buffalofishes(Ictiobus spp.), and gars(Lepisosteus spp.) generally increased during the same *** Although not possible to conclude assemblage shifts were entirely related to bigheaded carps due to the absence of an appropriate reference system where carps did not establish, the wide establishment of these carps is one of the most pervasive changes to have occurred in the lower White

关键词： Bigheaded carp Silver carp Aquatic nuisance species Fish assemblage Oxbow lake Large river

Kriging-boosted CR modeling for prompt infill drilling optimization

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Petroleum 2024年第1期10卷 39-48页

作者： elizaveta S.Gladchenko Anna e.Gubanova Denis M.Orlov Dmitry A.Koroteev Skolkovo Institute of Science and Technology Russian Federation Digital Petroleum LLC Russian Federation

The capacitance-resistance model(CRM)has been a useful physics-based tool for obtaining production forecasts for ***,the model's limitations make it difficult to work with real field cases,where a lot of various events *** events often include new well commissioning(NWC).We introduce a workflow that combines CRM concepts and kriging into a single tool to handle these types of events during history ***,it can be used for selecting a new well placement during infill *** make the workflow even more versatile,an improved version of CRM was *** takes into account wells shut-ins and performed workovers by additional adjustment of the model *** preliminary re-weighing and interpolating these coefficients using kriging,the coefficients for potential wells can be *** approach was validated using both synthetic and real datasets,from which the cases of putting new wells into operation were *** workflow allows a fast assessment of future well performance with a minimal set of reservoir *** way,a lot of well placement scenarios can be considered,and the best ones could be chosen for more detailed studies.

关键词： Capacitance-resistance model(CRM) Field development optimization Infill drilling Interwell connectivity Kriging New well commissioning(NWC)

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Cloud Datacenter Selection Using Service Broker Policies:A Survey

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Computer Modeling in engineering & Sciences 2024年第4期139卷 1-41页

作者： Salam Al-e’mari Yousef Sanjalawe Ahmad Al-Daraiseh Mohammad Bany Taha Mohammad Aladaileh Department of Information Security Faculty of ITUniversity of PetraAmman11196Jordan Department of Cybersecurity School of ITAmerican University of Madaba(AUM)Amman11821Jordan Department of Computer Science School of ITAmerican University of Madaba(AUM)Amman11821Jordan Department of Data Science and Artificial Intelligence School of ITAmerican University of Madaba(AUM)Amman11821Jordan

Amid the landscape of Cloud Computing(CC),the Cloud Datacenter(DC)stands as a conglomerate of physical servers,whose performance can be hindered by bottlenecks within the realm of proliferating CC services.A linchpin in CC’s performance,the Cloud Service Broker(CSB),orchestrates DC *** to adroitly route user requests with suitable DCs transforms the CSB into a bottleneck,endangering service *** tackle this,deploying an efficient CSB policy becomes imperative,optimizing DC selection to meet stringent Qualityof-Service(QoS)*** numerous CSB policies,their implementation grapples with challenges like costs and *** article undertakes a holistic review of diverse CSB policies,concurrently surveying the predicaments confronted by current *** foremost objective is to pinpoint research gaps and remedies to invigorate future policy ***,it extensively clarifies various DC selection methodologies employed in CC,enriching practitioners and researchers *** synthetic analysis,the article systematically assesses and compares myriad DC selection *** analytical insights equip decision-makers with a pragmatic framework to discern the apt technique for their *** summation,this discourse resoundingly underscores the paramount importance of adept CSB policies in DC selection,highlighting the imperative role of efficient CSB policies in optimizing CC *** emphasizing the significance of these policies and their modeling implications,the article contributes to both the general modeling discourse and its practical applications in the CC domain.

关键词： Cloud computing cloud service broker datacenter selection quality-of-service user request