From Digital Human Modeling to Human Digital Twin: Framework and Perspectives in Human Factors

The human digital twin(HDT)emerges as a promising human-centric technology in Industry 5.0,but challenges remain in human modeling and simulation.Digital human modeling(DHM)provides solutions for modeling and simulating human physical and cognitive aspects to support ergonomic analysis.However,it has limitations in real-time data usage,personalized services,and timely interaction.The emerging HDT concept offers new possibilities by integrating multi-source data and artificial intelligence for continuous monitoring and assessment.Hence,this paper reviews the evolution from DHM to HDT and proposes a unified HDT framework from a human factors perspective.The framework comprises the physical twin,the virtual twin,and the linkage between these two.The virtual twin integrates human modeling and AI engines to enable model-data-hybrid-enabled simulation.HDT can potentially upgrade traditional ergonomic methods to intelligent services through real-time analysis,timely feedback,and bidirectional interactions.Finally,the future perspectives of HDT for industrial applications as well as technical and social challenges are discussed.In general,this study outlines a human factors perspective on HDT for the first time,which is useful for cross-disciplinary research and human factors innovation to enhance the development of HDT in industry.

Evaluation of Maxillary Dental Arch Widths in Individuals Having Unilateral and Bilateral Cleft Lip and Palate Using Three-Dimensional Digital Models

Aim: Maxillary dental arch widths were evaluated in individuals having unilateral (UCLP) and bilateral (BCLP) cleft lip and palate (CLP) using three-dimensional (3D) digital models. Material and Method: The study had been conducted on 80 individuals aged between 14 - 17 years having UCLP and BCLP. 40 of the individuals had UCLP, whereas 40 had BCLP. The maxillary dental models taken from patients before the treatment were scanned using Orthomodel Programme (v.1.01, Orthomodel Inc., Istanbul, Turkey) to obtain 3D imagery. Student’s t-test was used in order to assess the data obtained by using SPSS software version 22.0. Results: In BCLP, the average inter-canine distance was 17.44 ± 1.31 mm, the average inter-molar distance was 36.57 ± 1.12 mm, while inter-canine/inter-molar ratio was 0.47. Whereas in UCLP, it was 25.10 ± 0.63 mm, 42.20 ± 0.53 mm and 0.59. The inter-canine distance in UCLP was found to be large enough to be statistically significant (p 0.05), even though there were differences in inter-molar widths. Conclusion: For the stable orthodontic treatment results, one of the most important points is arch form and widths to be coherent with each other. In our study, the increase of inter-canine distance seen in UCLP indicates that in the cleft region, the maxillary arch is inclined over to the back, while the same situation in BCLP suggests that the maxillary segments are collapsed inside. The difference in the arch is highly affected by the primary surgical treatment.

Applications and research trends of digital human models in the manufacturing industry

Virtual reality(VR)has been widely used in various manufacturing industries,and VR-based virtual manufacturing has received significant attention in the current intelligent manufacturing era.Digital human models(DHMs)are essential for virtual manufacturing applications.Additionally,researching new applications of DHMs has developed into an important academic research field.This paper aims to identify the applications and research trends of DHMs in the manufacturing industry and to provide a reference for the continued development of virtual manufacturing and DHMs.We selected a total of 49 related articles from a large number of articles published between 2014 and 2019.The applications of DHMs in the manufacturing industry are analyzed from different perspectives and various relevant technical limitations are discussed.The results indicate that the applications of DHMs differ significantly between different types of fields.The automotive industry is the main application field for DHMs,and assembly/maintenance simulations and evaluations are the main application types.Additionally,there are still some limitations in the establishment of virtual environments,motion control,and DHM evaluation that should be addressed.Finally,research trends in the application of DHMs are illustrated and discussed,including the planning and assessment of human-robot collaboration systems,the combination of DHMs and augmented reality,and improved motion planning for DHMs.In summary,the application of DHMs can improve the realism and effectiveness of virtual manufacturing,and DHMs will be more widely and deeply studied and applied in various manufacturing industries in the near future.

Cosmetic Safety Evaluation Based on In Vitro Three-dimensional Reconstructed Human Epidermis(3D-RHE) Models

Cosmetic safety evaluation employs a series of toxicological tests, on both qualitative and quantitative levels, to assess the potential risks for the daily use of selected cosmetic ingredients and final products. Traditionally, safety evaluation of cosmetics uses animal tests. With the development of in vitro science and the 3R （Reduction, Replacement and Refinement） principle, three-dimensional reconstructed human epidermis （3D-RHE） models have been developed and widely applied in cosmetic safety evaluation. Reconstructed human skin models possess anatomy and metabolism biology similar to real human tissue. This paper reviews the current application of 3D-RHE models in the safety evaluation of skin irritation, eye irritation, phototoxicity and genotoxicity potential of cosmetic ingredients/formulas. The advantages and disadvantages of using skin models are also discussed, and comments and suggestions are given for its future development.

Application of Digital Technology in Road and Bridge Design

With the development and progress of science and technology,road and bridge design has experienced rapid development,from the initial manual drawing design to the popularity of Computer-Aided Design(CAD),and then to today’s digital software design era.Early designers relied on hand-drawn paper design forms which was time-consuming and error-prone.Digital support for road and bridge design not only saves the design time but the design quality has also achieved a qualitative leap.This paper engages in the application of digital technology in road and bridge design,to provide technical reference for China’s road and bridge engineering design units,to promote the popularity of Civil3D and other advanced design software in the field of engineering design and development,ultimately contributing to the sustainable development of China’s road and bridge engineering.

Digitizing the Undigitized: Converting Traditional Archaeological Records into Computerized, Three-Dimensional Site Reconstruction

Archaeological excavation involves disintegration, removal, and reassembly of the archaeological record;as such it is considered by many to be an unrepeatable, destructive activity. This perception has contributed to an advancement in archaeological practice, namely, the development of computerized recording systems that digitally record archaeological excavations spatially and volumetrically during fieldwork. This paper is concerned with those archaeological sites where digital field recording has not been done. These sites, recorded by traditional methods, should not be excluded from attempts to restructure the spatial, volumetric, and stratigraphic archaeological data. A thorough methodology for the conversion of traditional records into digitized data is presented, including the detailed procedures required for three-dimensional plotting of recorded data—both the excavated material and the drawn site maps and cross-sections. Finally, the use of these methods is demonstrated on a complex Early to Middle Pleistocene site, illustrating the benefits of digitization and three-dimensional reconstruction in resolving stratigraphic and spatial questions.

Information Models for Forecasting Nonlinear Economic Dynamics in the Digital Era

The aim of this study was to develop an adequate mathematical model for long-term forecasting of technological progress and economic growth in the digital age (2020-2050). In addition, the task was to develop a model for forecast calculations of labor productivity in the symbiosis of “man + intelligent machine”, where an intelligent machine (IM) is understood as a computer or robot equipped with elements of artificial intelligence (AI), as well as in the digital economy as a whole. In the course of the study, it was shown that in order to implement its goals the Schumpeter-Kondratiev innovation and cycle theory on forming long waves (LW) of economic development influenced by a powerful cluster of economic technologies engendered by industrial revolutions is most appropriate for a long-term forecasting of technological progress and economic growth. The Solow neoclassical model of economic growth, synchronized with LW, gives the opportunity to forecast economic dynamics of technologically advanced countries with a greater precision up to 30 years, the time which correlates with the continuation of LW. In the information and digital age, the key role among the main factors of growth (capital, labour and technological progress) is played by the latter. The authors have developed an information model which allows for forecasting technological progress basing on growth rates of endogenous technological information in economics. The main regimes of producing technological information, corresponding to the eras of information and digital economies, are given in the article, as well as the Lagrangians that engender them. The model is verified on the example of the 5th information LW for the US economy (1982-2018) and it has had highly accurate approximation for both technological progress and economic growth. A number of new results were obtained using the developed information models for forecasting technological progress. The forecasting trajectory of economic growth of developed countries (on the example of the USA) on the upward stage of the 6th LW (2018-2042), engendered by the digital technologies of the 4th Industrial Revolution is given. It is also demonstrated that the symbiosis of human and intelligent machine (IM) is the driving force in the digital economy, where man plays the leading role organizing effective and efficient mutual work. Authors suggest a mathematical model for calculating labour productivity in the digital economy, where the symbiosis of “human + IM” is widely used. The calculations carried out with the help of the model show: 1) the symbiosis of “human + IM” from the very beginning lets to realize the possibilities of increasing work performance in the economy with the help of digital technologies;2) the largest labour productivity is achieved in the symbiosis of “human + IM”, where man labour prevails, and the lowest labour productivity is seen where the largest part of the work is performed by IM;3) developed countries may achieve labour productivity of 3% per year by the mid-2020s, which has all the chances to stay up to the 2040s.

3D Vector Reconstruction of the Typical Cervical Vertebra from Anatomical Sections of Korean Visible Human at the Laboratory of Clinical and Digital Anatomy of Paris Descartes University

Aim: To carry out a 3D vector reconstruction of the typical cervical vertebra from anatomical sections of the “Korean Visible Human” for educational purposes. Material and Methods: The anatomical subject was a 33-year-old Korean man who died of leukemia. He was 164 cm tall and weighed 55 kg. This man donated his body to science. Her body was frozen and cut into several anatomical sections after an MRI and CT scan. These anatomical sections were made using a special saw called a 0.2 mm thick cryomacrotome. Thus 8100 cuts were obtained. Only the sections numbered 940 to 1200 were used for our study. A segmentation by manual contouring of the different parts of the typical cervical vertebra was made using the software Winsurf version 3.5 on a laptop PC running Windows 7 equipped with a Ram of 8 gigas. Results: Our 3D vector model of the typical cervical vertebra is easily manipulated using the Acrobat 3DPDF interface. Each part of the vertebra accessible in a menu can be displayed, hidden or made transparent, and 3D labels are available as well as educational menus for learning anatomy. Conclusion: This original work constitutes a remarkable educational tool for the anatomical study of the typical cervical vertebra and can also be used as a 3D atlas for simulation purposes for training in therapeutic gestures.

The impact of the digital economy on the servitization of industrial structures: the moderating effect of human capital

The digital economy,which was born during the late third technological revolution,has caused significant economic and societal changes.Amid sluggish global economic growth,China’s economy is facing upgrades and transformations.The sample selection for this study was conducted from 2013 to 2020.Data related to the digital economy and servitization of the industrial structure of 30 Chinese provinces,municipalities,and autonomous regions were collected.This study presents the human capital variable,based on which an econometric analysis was conducted,and examines its moderating effect.The findings indicate that even after the replacement variable indicator’s robustness test,the relationship between the digital economy and the servitization of industrial structures remains unchanged.This study demonstrats that the quality of human capital plays a positive role in this effect.Finally,a heterogeneity test demonstrated that there are different pathways for the impact of the digital economy on the servitization of industrial structures in the eastern,central,and western regions.This study provides evidence to help researchers understand the moderating utility of human capital.

Extraction of Feature Points for Non-Uniform Rational B-Splines(NURBS)-Based Modeling of Human Legs

Methods of digital human modeling have been developed and utilized to reflect human shape features.However,most of published works focused on dynamic visualization or fashion design,instead of high-accuracy modeling,which was strongly demanded by medical or rehabilitation scenarios.Prior to a high-accuracy modeling of human legs based on non-uniform rational B-splines(NURBS),the method of extracting the required quasi-grid network of feature points for human legs is presented in this work.Given the 3 D scanned human body,the leg is firstly segmented and put in standardized position.Then re-sampling of the leg is conducted via a set of equidistant cross sections.Through analysis of leg circumferences and circumferential curvature,the characteristic sections of the leg as well as the characteristic points on the sections are then identified according to the human anatomy and shape features.The obtained collection can be arranged to form a grid of data points for knots calculation and high-accuracy shape reconstruction in future work.

Physical model test and application of 3D printing rock-like specimens to laminated rock tunnels

Weak structural plane deformation is responsible for the non-uniform large deformation disasters in layered rock tunnels,resulting in steel arch distortion and secondary lining cracking.In this study,a servo biaxial testing system was employed to conduct physical modeling tests on layered rock tunnels with bedding planes of varying dip angles.The influence of structural anisotropy in layered rocks on the micro displacement and strain field of surrounding rocks was analyzed using digital image correlation(DIC)technology.The spatiotemporal evolution of non-uniform deformation of surrounding rocks was investigated,and numerical simulation was performed to verify the experimental results.The findings indicate that the displacement and strain field of the surrounding layered rocks are all maximized at the horizontal bedding planes and decrease linearly with the increasing dip angle.The failure of the layered surrounding rock with different dip angles occurs and extends along the bedding planes.Compressive strain failure occurs after excavation under high horizontal stress.This study provides significant theoretical support for the analysis,prediction,and control of non-uniform deformation of tunnel surrounding rocks.

Construction and visualization of high-resolution three-dimensional anatomical structure datasets for Chinese digital human

The objective of the China Digital Human Project (CDH) is to digitize and visualize the anatomical structures of human body. In the project, a database with information of morphology, physical charac-teristics and physiological function will be constructed. The raw data of CDH which was completed in the Southern Medical University is employed. In Huazhong University of Science and Technology (HUST), the frozen section images are preprocessed, segmented, labeled in accordance with the major organs and tissues of human beings, and reconstructed into three-dimensional (3D) models in parallel on high performance computing clusters (HPC). Some visualization software for 2D atlas and 3D mod-els are developed based on the new dataset with high resolution (0.1mm×0.1mm×0.2mm). In order to share, release and popularize the above work, a website (www.vch.org.cn) is online. The dataset is one of the most important parts in the national information database and the medical infrastructure.

Three-dimensional cell culture models for investigating human viruses

Three-dimensional(3D) culture models are physiologically relevant, as they provide reproducible results, experimental flexibility and can be adapted for high-throughput experiments. Moreover,these models bridge the gap between traditional two-dimensional(2D) monolayer cultures and animal models. 3D culture systems have significantly advanced basic cell science and tissue engineering, especially in the fields of cell biology and physiology, stem cell research, regenerative medicine, cancer research, drug discovery, and gene and protein expression studies. In addition,3D models can provide unique insight into bacteriology, virology, parasitology and host-pathogen interactions. This review summarizes and analyzes recent progress in human virological research with 3D cell culture models. We discuss viral growth, replication, proliferation, infection, virus-host interactions and antiviral drugs in 3D culture models.

Integrated Framework for Vehicle Interior Design Using Digital Human Model

Evaluating the human friendliness of vehicles is essential for designing new vehicles since large numbers of human-machine interactions occur frequently inside vehicles. In this research, we develop an integrated framework for vehicle interior design using a digital human model （DHM）. In this framework, the knowledge-based parametric modelling function of vehicles is implemented using a commercial computer-aided design （CAD） system. The combination of the DHM and the CAD system enables designers into carry out ergonomic evaluations of various human-vehicle interactions and understand the effects of modifications of vehicle design parameters on occupants during designing. Further, the information on human-vehicle interaction obtained using this system can be transmitted to dedicated biomechanical analysis software. By analysing human motions inside vehicles using such software, we can obtain optimized interior design parameters.

Application of three-dimensional digitalized reconstruction of latissimus dorsi myocutaneous flap

Developments of digital technology and three-dimensional(3D)reconstruction allowed a precise description of anatomic structures.With the introduction of Visible Human Project and Virtual Chinese Human(VCH)techniques,more detailed anatomic images could be obtained.Digitized visible models of these structures can be applied as a useful tool in clinical training.The aim of this study was to reconstruct the normal structures of thoracodorsal artery in 3D images and to establish the digitized visible models of latissimus dorsi myocutaneous(LDM)flap.The cross-sectional images from the four VCH datasets were reviewed to study LDM and thoraco-dorsal artery structures on a section-by-section basis.Next,two adult fresh cadaver specimens were perfused with lead oxide-gelatine mixture and subject to radio-graphic CT scanning on their torsos.The cross-sectional images from the CT images were reviewed to study thor-acodorsal artery structures.Three-dimensional computer-ized reconstructions of LDM flap structures were conducted from these datasets by using Amira 3.1(TGS)software respectively.The 3D reconstructed visible models established from these datasets perfectly displayed the anatomic characteristics of LDM flap.

Era of the 4D animal model

Revealing the entire dynamics of pathogenesis is critical for understanding,preventing and treating human disease but is limited by systematic clinical sampling.This drawback can be overcome with animal model studies.Recent advances in phenotyping,omics and bioinformatics technologies promote the development of the 4D animal model to simulate and digitally display the spatiotemporal landscapes of phenotypes and molecular dynamics in human diseases and reveal novel targets for diagnosis and therapy.In this commentary,the origin,supporting technologies,content,function and application,and advantages of 4D animal models over clinical studies and traditional animal models,as well as their limitations,are presented.

The modelling and application of cross-scale human behavior in realizing the shop-floor digital twin[version 1;peer review:1 approved with reservations,1 not approved]

The digital twin shop-floor has received much attention from the manufacturing industry as it is an important way to upgrade the shop-floor digitally and intelligently.As a key part of the shop-floor,humans'high autonomy and uncertainty leads to the difficulty in digital twin modeling of human behavior.Therefore,the modeling system for cross-scale human behavior in digital twin shop-floors was developed,powered by the data fusion of macro-behavior and micro-behavior virtual models.Shop-floor human macro-behavior mainly refers to the role of the human and their real-time position.Shop-floor micro-behavior mainly refers to real-time human limb posture and production behavior at their workstation.In this study,we reviewed and summarized a set of theoretical systems for cross-scale human behavior modeling in digital twin shop-floors.Based on this theoretical system,we then reviewed modeling theory and technology from macro-behavior and micro-behavior aspects to analyze the research status of shop-floor human behavior modeling.Lastly,we discuss and offer opinion on the application of cross-scale human behavior modeling in digital twin shop-floors.Cross-scale human behavior modeling is the key for realizing closed-loop interactive drive of human behavior in digital twin shop-floors.

文化遗产数字叙事信任模型:概念与框架

信任是数字环境下文化遗产数字叙事的基础。文化遗产数字叙事是一种具有重构和演绎特质的叙事方式,在数字化、数据化和艺术化阶段会产生不同的信任问题。作为一种特殊的信息系统,文化遗产数字叙事的人机交互特征体现出系统、信息和用户之间的相互连通和协同影响,系统叙事的可信度和用户体验的信任感构成了信任模型的双向动态互动,涉及文化遗产信息资源、叙事性架构、数字化呈现、系统本身的功能建设和知识服务,以及用户的意图和行动。文化遗产数字叙事信任模型不仅有助于提升文化遗产的数智化活化利用水平,促进对文化遗产信息资源的深度挖掘、叙事内容的创意演绎、文化内涵的有效阐释与呈现,而且有望为可信的文化遗产数字叙事提供理论和实践指导,助力文化遗产数字化转型发展。

数字人文时代下档案开发利用的新模式与新路径探索

档案作为承载和凝结人类社会历史记忆与文化遗产的优质载体,在数字人文理念和研究方法的驱动下,档案开发利用的创新转型迎来新机遇。在识别与分析数字人文环境下档案资源开发利用新需求与新特点的基础上,提炼档案开发利用模式创新的新思路,探索推动档案开发利用变革的新路径。在数字人文时代,档案开发利用呈现数字化和语义化的资源深加工、知识图谱驱动的语义关联组织、虚实融合的情境化呈现、众创众包的社会协同利用等新模式。推动档案开发利用变革与转型,需要从构建数据基础设施、建立跨学科研究服务团队、深度运用前沿数智技术、拓展虚实融合服务空间、打造“档案+数字人文”品牌等方面统筹谋划、协同发力。未来,档案工作要以开放创新的视野,积极投身数字人文实践,在传承优秀传统文化、服务经济社会发展中彰显档案新价值。

数字人文类开放数据竞赛价值共创的过程模型及机理研究

开放共享数据是构建数据生态体系的重要途径。数字人文类开放数据竞赛能够促进文化数字化成果转化与全民共享。本研究基于服务生态系统视角,采用探索性案例研究方法,获取四届上海图书馆开放数据竞赛案例数据,分析竞赛行动者间价值共创的过程及内在机理。研究发现,数字人文类开放数据竞赛价值共创产生的新兴价值包括历史价值、经济价值、经验价值、社交价值、文化价值和社会价值。共创过程模型包含价值共识、价值共生、价值共融和价值共传。通过隐性价值主张与显性产品价值的循环转化,构成连续、动态的价值共创螺旋。竞赛的价值产出随生态系统不断扩展,呈现持续增长的趋势。本研究补充了从服务生态系统视角对价值共创过程及机理的现象学研究,并为数字人文开放创新信息实践提供了建议。