UAV-Assisted Dynamic Avatar Task Migration for Vehicular Metaverse Services: A Multi-Agent Deep Reinforcement Learning Approach

Avatars, as promising digital representations and service assistants of users in Metaverses, can enable drivers and passengers to immerse themselves in 3D virtual services and spaces of UAV-assisted vehicular Metaverses. However, avatar tasks include a multitude of human-to-avatar and avatar-to-avatar interactive applications, e.g., augmented reality navigation,which consumes intensive computing resources. It is inefficient and impractical for vehicles to process avatar tasks locally. Fortunately, migrating avatar tasks to the nearest roadside units(RSU)or unmanned aerial vehicles(UAV) for execution is a promising solution to decrease computation overhead and reduce task processing latency, while the high mobility of vehicles brings challenges for vehicles to independently perform avatar migration decisions depending on current and future vehicle status. To address these challenges, in this paper, we propose a novel avatar task migration system based on multi-agent deep reinforcement learning(MADRL) to execute immersive vehicular avatar tasks dynamically. Specifically, we first formulate the problem of avatar task migration from vehicles to RSUs/UAVs as a partially observable Markov decision process that can be solved by MADRL algorithms. We then design the multi-agent proximal policy optimization(MAPPO) approach as the MADRL algorithm for the avatar task migration problem. To overcome slow convergence resulting from the curse of dimensionality and non-stationary issues caused by shared parameters in MAPPO, we further propose a transformer-based MAPPO approach via sequential decision-making models for the efficient representation of relationships among agents. Finally, to motivate terrestrial or non-terrestrial edge servers(e.g., RSUs or UAVs) to share computation resources and ensure traceability of the sharing records, we apply smart contracts and blockchain technologies to achieve secure sharing management. Numerical results demonstrate that the proposed approach outperforms the MAPPO approach by around 2% and effectively reduces approximately 20% of the latency of avatar task execution in UAV-assisted vehicular Metaverses.

MV-Honeypot:Security Threat Analysis by Deploying Avatar as a Honeypot in COTS Metaverse Platforms

Nowadays,theuse of Avatars that are unique digital depictions has increased by users to access Metaverse—a virtual reality environment—through multiple devices and for various purposes.Therefore,the Avatar and Metaverse are being developed with a new theory,application,and design,necessitating the association of more personal data and devices of targeted users every day.This Avatar and Metaverse technology explosion raises privacy and security concerns,leading to cyber attacks.MV-Honeypot,or Metaverse-Honeypot,as a commercial off-the-shelf solution that can counter these cyber attack-causing vulnerabilities,should be developed.To fill this gap,we study user’s engagements with Avatars in Metaverse,analyze possible security vulnerabilities,and create a model named Simplified Avatar Relationship Association with Non-linear Gradient(SARANG)that draws the full diagram of infrastructure components and data flow through accessing Metaverse in this paper.We also determine the most significant threat for each component’s cyberattacks that will affect user data and Avatars.As a result,the commercial off-the-shelf(COTS)of the MV-Honeypot must be established.

Data,digital worlds,and the avatarization of health care

Significant technological trends are impacting health care,from consumerisation,datafication,circular economy,and platformization of services.Web 3.0,or the Internet of Value,enables direct peer-to-peer value exchange,opening up new business models that will impact health care.Among the many technologies that will also be part of the healthcare transformation is artificial intelligence,which shocked the world with the debut of ChatGPT in 2022.This opinion piece will explore how AI underpins the health transformation and,far from being an enemy of health,is the critical friend health care has been waiting for.

基于Avatar用户的消费行为分析

互联网盈利模式的选择是困扰国内互联网企业的重要难题,而Avatar是被国外诸多市场证明为极其成功的互联网运营及盈利模式。通过实证调研的方式分析Avatar产品的用户的消费行为特征,对互联网企业的产品设计和运营策略策划无疑会有重要启发。

Avatar虚拟环境支持CALLA模式的教学研究

基于Avatar的学习系统设计为英语学习者提供了专属的、富有沉浸感的网络三维虚拟现实(Virtual Reality,VR)环境,延伸了课堂所无法实现的交互体验。认知学术语言学习方法(The Cognitive Academic Language Learning Approach,CALLA)成功地促进了学习者语言学习策略的训练,在英语学习中得到广泛应用。文章以Avatar支持CALLA模式的机制设计为研究思路,以细化师生的活动任务和评价指标为实施指南,开展了Avatar虚拟环境支持CALLA模式的英语教学活动,并通过实证研究验证了该模式在中学英语教学中的有效性。

基于符号消费的Avatar盈利模式研究

本文在分析网络符号消费特征的基础上,对Avatar模式的符号消费商务过程进行解析,研究Avatar的商务盈利模式,并总结出该盈利模式的主要经济特征。

Avatar中的三维动画技术应用

电影巨片Avatar被誉为电影史上具有里程碑式的3D精品，本文对Avatar所运用的三维动画技术进行介绍；本文从虚拟摄像机技术、表情抓取技术、动作捕捉技术和3D立体摄影机这四个方面，深入探讨影片Avatar所取得的主要技术突破。

Nicolet AVATAR 360FT—IR分辨率设置对谱图结果的影响

本文对Nicolet AVATAR 360FT-IR测试操作中分辨率设置和使用进行了详细的探讨，阐述了分辨率的合理设置对扫描谱图结果的影响。实验发现，分辨率大小的设置，对常规有机物的红外光谱图影响不大，但对如过氧杂多化合物，合理的分辨率对扫描谱图结果影响较大。

Teen reactions to a self-representational avatar:A qualitative exploration

Purpose:This research presents findings from a qualitative exploration of the reactions of adolescents(12-14 years old)to navigating an exergame with an avatar created from multiple scans of the player(referred to as a self-representational avatar).Methods:Post-gameplay interviews were conducted with adolescents following participation in a 20-min laboratory session(21.2±0.8 min,mean±SD)where the self-representational avatar was navigated through an exergame.Verbatim transcripts(n=40)were coded and analyzed by 2 independent coders using hybrid thematic analysis for this secondary data analysis.Codes were reviewed to identify themes representing adolescents’reactions.Results:Four themes emerged.Adolescents connected with their avatars and felt protective toward them,which influenced their actions in the exergame and contributed to their overall game enjoyment.Conclusion:Creating exergames navigated by a self-representational avatar was an enjoyable experience and influenced gameplay.Future research should explore the effect of this approach on gameplay frequency and intensity over time.

Mouse avatar models derived from patients with colorectal cancer liver metastases provide a well-characterized platform for preclinical studies

Objective:The liver is the most common metastatic site in advanced colorectal cancer.Most patients with colorectal cancer liver metastasis(CRLM)cannot benefit from currently available treatment.Patient-derived xenograft(PDX)models with defined molecular signatures are attractive preclinical models and essential for preclinical studies.

Use of zebrafish embryos as avatar of patients with pancreatic cancer:A new xenotransplantation model towards personalized medicine

BACKGROUND The response to chemotherapy treatment of patients with pancreatic ductal adenocarcinoma(PDAC)is difficult to predict and the identification of patients who most likely will benefit from aggressive chemotherapy approaches is crucial.The concept of personalized medicine has emerged in the last years with the objective to tailor the medical treatment to the individual characteristics of each patient,and particularly to the tumor biology of each patient.The need for invivo xenotransplantation models for cancer patients has increased exponentially,and for this reason zebrafish avatars have gained popularity.Preliminary studies were conducted also with PDAC tissue.AIM To develop a simple,not expensive,diffusible zebrafish embryo model as avatar for patients affected by PDAC.METHODS Tumor tissue was taken from the surgical specimen by the histopathologist.After its fragmentation into small pieces,they are stained with CM-Dil.Small pieces of stained tissue were transplanted into the yolk of wt AB zebrafish embryos with a glass capillary needle.Embryos were incubated at 35°C in E3 medium supplemented with 1%Pen/Strep in the presence or absence of drugs for the following days in respect of the treatment plan(Gemcitabine;Gemcitabine and Oxaliplatin;Gemcitabine and nab-Paclitaxel;5-Fluorouracil and Folinic acid and Oxaliplatin and Irinotecan).The response of zebrafish xenografts to the chemotherapy options has been analyzed by monitoring the fluorescent stained area at 2 h post injection(hpi),1 d and 2 d post injection(dpi).In each time point,the mean size of the stained area was measured by ImageJ and it was normalized with respect to the 1 dpi time point mean relative tumor area(RTA).We evaluated the effect of the chemotherapy exposition comparing the mean RTA of each treated subgroup and the control group and evaluating the percentage reduction of the mean RTA by comparing each treated subgroup with the control group.RESULTS Between July 2018 and October 2019,a total of 15 patients with pancreatic cancer were prospectively enrolled.In all cases,it was possible to take a fragment of the tumor from the surgical specimen for the xenotransplantation in the zebrafish embryos.The histological examination confirmed the presence of a PDAC in all cases.In absence of chemotherapy(control group),over time the Dil-stained area showed a statistically significant increase in all cases.A statistically significant reduction of the mean RTA in the treated subgroups for at least one chemotherapy scheme was reported in 6/15(40%)cases.The analysis of the percentage reduction of the RTA in treated subgroups in comparison to the control group revealed the presence of a linear relationship in each subgroup between the percentage reduction of the RTA and the number of cases reporting each percentage threshold considered for the analysis.CONCLUSION Our model seems to be effective for the xenotransplantation of PDAC tissue and evaluation of the effect of each chemotherapy scheme on the xenotransplanted tumor tissue.

参数设计软件AVATAR与造纸机通用零部件图库的建立

一、总论 AVATAR是加在CIM CAD上的一个软件模块。它与CIM CAD(3.0及以上版)一起运行,提供参数化绘图。在计算机辅助设计或绘图领域,经常会碰到形状大致相同唯尺寸有所差别的几何图形。对于这些几何图形,用AVATAR只需绘制一张图就够了。尺寸用参数标注,对于其中某一形状的几何图形,只要赋予各参数具体的数值,AVATAR就能绘出实际尺寸的图形。

Genre Variation in the Film Avatar

As a revolutionary sci-fi epic, Avatar, is not only a milestone of screen history, but also the number one grossing movie of all time. The film Avatar is just a typical representation of Hollywood's hegemonic purpose--making American cultural hegemonic ideologies conquer "the others" in an unconscious way and making big sum of commercial takes. The main way of realizing this penetration is through variation of genres.

Avatar采访记

这些天．Avatar显得有点太火爆。它在以新的感觉冲击了广大影迷内心的同时．也让国内的导演们有些冷汗涟涟．甚至有人自嘲说连“磕头”的心都有．虽然相信那只是自嘲。一般性的成王败寇论，在这个时代已经发生变化．

“人类世”视域下的《阿凡达2》与多物种民族志想象

自1784年瓦特发明蒸汽机以来,人类工业化的现代文明进程给地球环境造成了无尽的灾难。当今地球已经进入一个由人类主导的新的地质时代——人类世,人与自然的关系得到重新审视。生态环境问题是卡梅隆的《阿凡达》两部曲中的重要言说对象,虽然潘多拉魔盒里的灾祸已在“人类世”被不幸释放,但《阿凡达》作为重要的影像人类学载体,以多物种民族志想像的关怀作为集合,关注“主体间性”的影像书写对人类与非人类二元边界的超越作用,所有的物种共同型塑着同一个生活的异域星球,展现了多物种共同体作为主导力量的救世景象。

手语数字人技术及智能应用研究

对智谱AI、腾讯、华为等头部企业打造的手语数字人产品进行梳理,研究和探讨我国代表性手语数字人产品的主要技术路线和智能应用。手语数字人的制作流程包括形象设计、建模、动作捕捉、驱动、渲染。通过多模型、多算法等AI技术集成实现手语数字人应用场景落地。智谱AI手语数字人核心技术含seq2seq模型、生成对抗网络,创造性地将对比学习引入mBart模型等。当前我国手语数字人在新闻播报、教育、国际赛事和重要会议翻译等方面实现智能应用。未来我国手语数字人技术有望迎来新突破,智能应用也将拓展到智慧医疗、智慧交通等更多领域。

基于关联事件场的智能化仿真社会实验方法

智能化进程正在迅速推动数字中国建设,不断改变相关社会和人文形态,同时引发了人工智能涉及的社会衍生风险等关键问题。在遵循社会伦理和隐私保护前提下,前瞻性探索新型人工智能社会实验模式,规范人工智能技术的发展,具有重要的现实意义。探讨了在特定社会实验环境下的事件场构建方式方法,以及人物、行为和场景三者的关联关系,基于数据和实验的社会化传导模式以及社会衍生效应进行预测。尝试通过前瞻性的虚拟仿真博弈实验,验证智能化仿真社会实验模式的有效性,为政府提供前瞻性的决策工具和智慧管理建议。

Real-Time Avatar Pose Transfer and Motion Generation Using Locally Encoded Laplacian Offsets

We propose a human avatar representation scheme based on intrinsic coordinates,which are invariant to isometry and insensitive to human pose changes,and an efficient pose transfer algorithm that can utilize this representation to reconstruct a human body geometry following a given pose.Such a pose transfer algorithm can be used to control the movement of an avatar model in virtual reality environments following a user's motion in real time.Our proposed algorithm consists of three main steps.First,we recognize the user's pose and select a template model from the database who has a similar pose;then,the intrinsic Laplacian offsets encoded in local coordinates are used to reconstruct the human body geometry following the template pose;finally,the morphing between the two poses is generated using a linear interpolation.We perform experiments to evaluate the accuracy and efficiency of our algorithm.We believe our proposed system is a promising human modeling tool that can be used in general virtual reality applications.

元宇宙之于课堂教学:机遇、挑战与应对

元宇宙是数字信息技术发展的未来形态,其内蕴的数字分身协作助手、虚实共在场景、超强社交网络体系以及联通共享的数据资源运用于课堂教学,将推动形成协同精准的教学范式,促生深度沉浸的教学样态,激发多维立体的教学交往形态,满足多元智能的教学评价需求。与此同时,元宇宙也可能带来教师胜任力不足,师生教学情境适应困难,师生交往情感疏离以及教学评价人文向度缺失的挑战。为应对此种挑战,需要大力提高教师的数字胜任力,强化师生多场景适应能力,塑造师生的理性教学交往行为,促进“质性”与“量化”评价的融合,提升教学评价的人文关怀。

生存论视域下教育元宇宙的内在风险及其应对

元宇宙的出现实现了人的虚拟存在,为个体的生命发展提供了无限可能。在元宇宙的影响下,教育领域将发生新的变革,即“教育元宇宙”的诞生,教育空间向虚拟维度延伸、教育时间显现情境化的特质、教育关系呈现虚实多元化的样态。但基于数据、算法的教育元宇宙具有单向度、封闭性、伦常松懈的消极特征,可能造成学生个体经验格式化、生命意义贫乏的问题,并使学生陷入自我角色化的危险。对此,在建构教育元宇宙时,应当以身体主体为尺度建构元宇宙中的身份认证机制,以现实世界为目的打造虚实融合的教育场景,并以生命关怀为指向实现教育伦理,从而化解风险并完成元宇宙带来的教育挑战。