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User Association in Ultra-Dense Small Cell Dynamic Vehicular Networks: A Reinforcement Learning Approach

Journal of Communications and Information Networks 2019年第1期4卷 1-12页

作者： Shipra Kapoor david grace Tim Clarke Department of Electronic Engineering University of YorkYO105DDUnited Kingdom

Network densification is envisioned as one of the key enabling technologies in the next generation and beyond wireless networks to satisfy the demand of high coverage and capacity whilst deliver an ultra-reliable low latency communication services especially to the users on the move.One of the fundamental tasks in wireless networks is user association.In the case of ultra-dense vehicular networks,due to the dense deployment and small coverage of the eNodeBs,there may be more than one eNodeB that may simultaneously satisfy the conventional maximum radio signal strength user association criteria.In addition to this,the spatial-temporal vehicle distribution in dynamic environments contribute significantly towards the rapidly changing radio environment that substantially impacts the user association,therefore,the network performance and user experience.This paper addresses the problem of user association in dynamic environments by proposing intelligent user association approach,variable-reward,quality-aware Q-learning(VR-QAQL)that has an ability to strike a balance between the number of handovers per transmission and system performance whilst a guaranteed network quality of service is delivered.The VR-QAQL technique integrates the control-theoretic concepts and the reinforcement learning approach in an LTE uplink,using the framework of an urban vehicular environment.The algorithm is assessed using large-scale simulation on a highway scenario at different vehicle speeds in an urban setting.The results demonstrate that the proposed VR-QAQL algorithm outperforms all the other investigated approaches across all mobility levels.

关键词： 5G access protocols adaptive algorithm control design dynamic range handover machine learning algorithms multiagent systems radio access networks uplink user centered design

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COOPERATIVE DIRECTIONAL INTER-CELL HANDOVER SCHEME IN HIGH ALTITUDE PLATFORM COMMUNICATIONS SYSTEMS

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Journal of Electronics(China) 2011年第2期28卷 249-257页

作者： Li Shufeng Wang Lijie david grace Ma Dongtang School of Electronic Science and Engineering National University of Defense Technology Changsha 410073 China Communications Research Group Department of Electronics University of York Heslington York 11010 5DD United Kingdom

A novel Cooperative Directional inter-cell Handover Scheme(CDHS) for High Altitude Platform(HAP) communications systems is proposed,in which the handover target cell and the two cells adjacent to this handover target cell work cooperatively to exploit the traffic fluctuation to improve handover performance.Users in the overlap area of the overloaded handover target cell will be forced to handover directionally before their optimal handover boundary in order to free up resources for the handover calls which would otherwise be dropped due to the shortage of resources and queue time out.Simulation results show that the handover call dropping probability is greatly reduced(at least 60%) compared with the general queue handover scheme,with little performance reduction to the call blocking probability,and the Not in the Best Cell(NBC) average time is only increased moderately.Moreover,an optimal cell radius can be achieved for a specific platform speed by minimizing the unified system performance,which is the linear combination of the handover call dropping probability and the NBC average time.

关键词： Inter-cell Handover High Altitude Platform(HAP) Dropping probability Blocking Probability

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Multipath Cognitive Routing in Integrated Multicast Satellite-HAP System Structures

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Journal of Electronic Science and Technology 2011年第1期9卷 41-45页

作者： Mohamed M.Elsokkary Mona M.Riad david grace Electronics and Communication Department Cairo University Communications Research Group University of York

A new multilayered inter satellite-high altitude platform （HAP） system routing algorithm is proposed,which is mainly based on multipath routing to ensure the network reliability.The proposed multipath routing scheme principally relies on splitting the traffic between different paths to make the best utilization of multiple routes.Linear programming is the main method used for multipath selection.The major constraints to the quality of service （QoS）（delay and link utilization） have been taken into account to meet the criteria of the advanced multimedia applications.Due to the effect of link utilization,the system encounters traffic flow oscillation between paths over time,which affects the system performance.Hence,to fix this issue,we propose a cognitive routing algorithm which reacts to the long-term changes of the traffic loads rather than short-term ones.The performance of the proposed routing techniques has been evaluated using appropriate simulation models and implemented by Matlab.

关键词： Cognitive routing multipath routing,satellite-high altitude platform.

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Employing electrochemically derived pH gradients for Lab-on-PCB protein preconcentration devices

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Microsystems & Nanoengineering 2024年第1期10卷 79-87页

作者： grace Maxted Pedro Estrela Despina Moschou Department of Electronic and Electrical Engineering University of BathBath BA27AYUK Centre for Bioengineering and Biomedical Technologies(CBio) University of BathBath BA27AYUK

Protein preconcentration is an essential sample preparation step for analysis in which the targeted proteins exist in low concentrations,such as bodily fluids,water,or wastewater.Nonetheless,very few practical implementations of miniaturized protein preconcentration devices have been demonstrated in practice,and even fewer have been integrated with other microanalytical steps.Existing approaches rely heavily on additional chemicals and reagents and introduce complexity to the overall assay.In this paper,we propose a novel miniaturized isoelectric focusing-based protein preconcentration screening device based on electrochemically derived pH gradients rather than existing chemical reagent approaches.In this way,we reduce the need for additional chemical reagents to zero while enabling device incorporation in a seamlessly integrated full protein analysis microsystem via Lab-on-PCB technology.We apply our previously presented Lab-on-PCB approach to quantitatively control the pH of a solution in the vicinity of planar electrodes using electrochemical acid generation through redox-active self-assembled monolayers.The presented device comprises a printed circuit board with an array of gold electrodes that were functionalized with 4-aminothiophenol;this formed a self-assembled monolayer that was electropolymerized to improve its electrochemical reversibility.Protein preconcentration was performed in two configurations.The first was open and needed the use of a holder to suspend a well of fluid above the electrodes;the second used microfluidic channels to enclose small volumes of fluid.Reported here are the resulting data for protein preconcentration in both these forms,with a quantitative concentration factor shown for the open form and qualitative proof shown for the microfluidic.

关键词： electrochemical proof qualitative

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Eco-ableism and access circularity in natural building

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Frontiers of Architectural Research 2024年第2期13卷 235-248页

作者： grace Schleck Lola Ben-Alon Barnard College Department of Architecture New YorkUSA Columbia University Graduate School of Architecture Planningand Preservation(GSAPP)New YorkUSA

The climate crisis disproportionately impacts disabled people. Yet climate-related advocacy, planning, and policymaking often neglect to thoughtfully include disabled people. Responding to this gap, disabled and neurodivergent environmental activists coined the term eco-ableism to describe discrimination and silencing toward disabled and neurodivergent people (i.e., ableism) arising in environmental spaces (i.e., eco-ableism). Relatedly, building operations and construction practices contribute a significant percentage of global, energy-related CO_(2) emissions annually, which calls into question the relationships between the impending climate crisis, disability justice, and architecture. Climate-specific, natural building materials and methods present a potential pathway toward a more sustainable built future: low-carbon, locally sourced, minimally processed, and nontoxic materials. Despite a critical overlap, there is little published research on material access in the production phase and human access in the occupation phase of natural buildings. Applying eco-ableism and material circularity in an architectural framework, this research aims to investigate the gaps and possibilities of access, natural material applications, and resulting US natural buildings informed by scholarship in critical disability studies and semi-structured interviews with natural building professionals.

关键词： Eco-ableism Critical disability studies Climate crisis and architecture Naturalmaterialsand methods

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Relating estimates of wood properties of birch to stem form, age and species

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Journal of Forestry Research 2024年第3期35卷 1-11页

作者： grace Jones Maria Ulan Mateusz Liziniewicz Johan Lindeberg Stergios Adamopoulos Teagasc Forestry Development Department Ashtown Research CentreDublin 15 D15DY05Ireland Research Institutes of Sweden(RISE) GoteborgSweden The Forest Research Institute of Sweden(Skogforsk) Ekebo 225026890SvalovSweden Department of Forestry and Wood Technology Linnaeus University35195VaxjoSweden Department of Forest Biomaterials and Technology Swedish University of Agricultural SciencesBox 700875007 UppsalaSweden

Birch has long suffered from a lack of active forest management,leading many researchers to use mate-rial without a detailed management history.Data collected from three birch(Betula pendula Roth,B.pubescens Ehrh.)sites in southern Sweden were analyzed using regression analysis to detect any trends or differences in wood proper-ties that could be explained by stand history,tree age and stem form.All sites were genetics trials established in the same way.Estimates of acoustic velocity(AV)from non-destructive testing(NDT)and predicted AV had a higher correlation if data was pooled across sites and other stem form factors were considered.A subsample of stems had radial profiles of X-ray wood density and ring width by year created,and wood density was related to ring number from the pith and ring width.It seemed likely that wood density was negatively related to ring width for both birch species.Linear models had slight improvements if site and species were included,but only the youngest site with trees at age 15 had both birch species.This paper indicated that NDT values need to be considered separately,and any predictive models will likely be improved if they are specific to the site and birch species measured.

关键词： Acoustic velocity Non-destructive testing Predictive models Regression analysis Wood density

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An adaptive machine learning-based optimization method in the aerodynamic analysis of a finite wing under various cruise conditions

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Theoretical & Applied Mechanics Letters 2024年第1期14卷 27-34页

作者： Zilan Zhang Yu Ao Shaofan Li grace X.Gu Department of Mechanical Engineering University of CaliforniaBerkeley 94720USA Department of Engineering Peking UniversityBeijing 100871China Department of Civil and Environmental Engineering University of CaliforniaBerkeley 94720USA

Conventional wing aerodynamic optimization processes can be time-consuming and imprecise due to the complexity of versatile flight missions.Plenty of existing literature has considered two-dimensional infinite airfoil optimization,while three-dimensional finite wing optimizations are subject to limited study because of high computational costs.Here we create an adaptive optimization methodology built upon digitized wing shape deformation and deep learning algorithms,which enable the rapid formulation of finite wing designs for specific aerodynamic performance demands under different cruise conditions.This methodology unfolds in three stages:radial basis function interpolated wing generation,collection of inputs from computational fluid dynamics simulations,and deep neural network that constructs the surrogate model for the optimal wing configuration.It has been demonstrated that the proposed methodology can significantly reduce the computational cost of numerical simulations.It also has the potential to optimize various aerial vehicles undergoing different mission environments,loading conditions,and safety requirements.

关键词： Aerodynamic optimization Computational fluid dynamics Radial basis function Finite wing Deep learning neural network

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Relative carcinogenicity of tacrolimus vs mycophenolate after solid organ transplantation and its implications for liver transplant care

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World Journal of Hepatology 2024年第4期16卷 650-660页

作者： Dorothy Liu Mark M Youssef Josephine A grace Marie Sinclair Department of Gastroenterology Austin HealthMelbourne 3084VictoriaAustralia Victorian Liver Transplant Unit Austin HealthMelbourne 3084VictoriaAustralia Department of Medicine University of MelbourneMelbourne 3084VictoriaAustralia

BACKGROUND De novo malignancy is a leading cause of late morbidity and mortality in liver transplant recipients.Cumulative immunosuppression has been shown to contribute to post-transplant malignancy(PTM)risk.There is emerging evidence on the differential carcinogenic risk profile of individual immunosuppressive drugs,independent of the net effect of immunosuppression.Calcineurin inhibitors such as tacrolimus may promote tumourigenesis,whereas mycophenolic acid(MPA),the active metabolite of mycophenolate mofetil,may limit tumour progression.Liver transplantation(LT)is relatively unique among solid organ transplantation in that immunosuppression monotherapy with either tacrolimus or MPA is often achievable,which makes careful consideration of the risk-benefit profile of these immunosuppression agents particularly relevant for this cohort.However,there is limited clinical data on this subject in both LT and other solid organ transplant recipients.AIM To investigate the relative carcinogenicity of tacrolimus and MPA in solid organ transplantation.METHODS A literature search was conducted using MEDLINE and Embase databases using the key terms“solid organ transplantation”,“tacrolimus”,“mycophenolic acid”,and“carcinogenicity”,in order to identify relevant articles published in English between 1st January 2002 to 11th August 2022.Related terms,synonyms and explosion of MeSH terms,Boolean operators and truncations were also utilised in the search.Reference lists of retrieved articles were also reviewed to identify any additional articles.Excluding duplicates,abstracts from 1230 records were screened by a single reviewer,whereby 31 records were reviewed in detail.Full-text articles were assessed for eligibility based on pre-specified inclusion and exclusion criteria.RESULTS A total of 6 studies were included in this review.All studies were large population registries or cohort studies,which varied in transplant era,type of organ transplanted and immunosuppression protocol used.Overall,there was no clear difference demonst

关键词： Immunosuppression Solid organ transplantation Liver transplantation Carcinogenicity Tacrolimus Mycophenolate

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Quantitative and qualitative subgenomic RNA profiles of SARS-CoV-2 in respiratory samples: A comparison between Omicron BA.2 and non-VOC-D614G

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Virologica Sinica 2024年第2期39卷 218-227页

作者： Zigui Chen Rita Way Yin Ng grace Lui Lowell Ling Agnes S.Y.Leung Chit Chow Siaw Shi Boon Wendy C.S.Ho Maggie Haitian Wang Renee Wan Yi Chan Albert Martin Li david Shu Cheong Hui Paul Kay Sheung Chan Department of Microbiology Faculty of MedicineThe Chinese University of Hong KongHong KongChina Department of Medicine and Therapeutics Faculty of MedicineThe Chinese University of Hong KongHong KongChina Department of Anaesthesia and Intensive Care Faculty of MedicineThe Chinese University of Hong KongHong KongChina Department of Paediatrics Faculty of MedicineThe Chinese University of Hong KongHong KongChina Department of Anatomical and Cellular Pathology Faculty of MedicineThe Chinese University of Hong KongHong KongChina Jockey Club School of Public Health and Primary Care Faculty of MedicineThe Chinese University of Hong KongHong KongChina Stanley Ho Centre for Emerging Infectious Diseases Faculty of MedicineThe Chinese University of Hong KongHong KongChina

The SARS-CoV-2 Omicron variants are notorious for their transmissibility,but little is known about their subgenomic RNA(sgRNA)expression.This study applied RNA-seq to delineate the quantitative and qualitative profiles of canonical sgRNA of 118 respiratory samples collected from patients infected with Omicron BA.2 and compared with 338 patients infected with non-variant of concern(non-VOC)-D614G.A unique characteristic profile depicted by the relative abundance of 9 canonical sgRNAs was reproduced by both BA.2 and non-VOCD614G regardless of host gender,age and presence of pneumonia.Remarkably,such profile was lost in samples with low viral load,suggesting a potential application of sgRNA pattern to indicate viral activity of individual patient at a specific time point.A characteristic qualitative profile of canonical sgRNAs was also reproduced by both BA.2 and non-VOC-D614G.The presence of a full set of canonical sgRNAs carried a coherent correlation with crude viral load(AUC¼0.91,95%CI 0.88–0.94),and sgRNA ORF7b was identified to be the best surrogate marker allowing feasible routine application in characterizing the infection status of individual patient.Further potentials in using sgRNA as a target for vaccine and antiviral development are worth pursuing.

关键词： Coronavirus SARS-CoV-2 Omicron BA.2 Non-VOC-D614G RNA-seq Subgenomic RNA(sgRNA)

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Acute Colonic Pseudo-Obstruction (ACPO): An Expanding Colon with Unusual Risk Factors

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Open Journal of Internal Medicine 2024年第2期14卷 167-174页

作者： Kelly Schulte Alyson Terry grace Boyle Dmitriy Scherbak HCA Healthone Sky Ridge Medical Center Lone Tree Colorado USA

The distention of the colon without mechanical or anatomical obstruction, Acute Colonic Pseudo-obstruction (ACPO), is a common condition occurring in the critically ill. ACPO in the setting of an acute pulmonary embolism and embolic stroke is a rarity. A 76-year-old female with shortness of breath, left hemiparesis and right-sided paresthesias presented with acute pulmonary embolism and acute infarcts of the left caudate nucleus, thalamus and occipital lobe. Her hospitalization was complicated with persistent distention of the large bowel without dilation of the small bowel. Empiric antibiotics were initiated without improvement and laboratory studies including Clostridium difficile were negative. She underwent nasogastric decompression and two decompressive colonoscopies with a resolution of her symptoms. This case illustrates an example of acute abdominal distension, without underlying etiology, in the setting of acute embolism of the pulmonary and cerebral vasculature. Early identification and action with decompressive colonoscopy were key to preventing further bowel damage or rupture.

关键词： Acute Colonic Pseudo-Obstruction ACPO Ogilvie’s Syndrome Colonic Dilation Acute Embolic Infarcts Cerebrovascular Accident Pulmonary Embolism PE

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