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Virtual reality based apps are the future of patient:Counseling
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作者 Ranjan K Behera Arvind K Morya +1 位作者 Parul C Gupta Arshi Singh 《World Journal of Clinical Cases》 SCIE 2025年第6期58-60,共3页
The use of virtual reality to educate preoperative patients has a positive impact on nurses as well as patients undergoing treatment.It can help improve patient satisfaction and improve favorable outcomes by reducing ... The use of virtual reality to educate preoperative patients has a positive impact on nurses as well as patients undergoing treatment.It can help improve patient satisfaction and improve favorable outcomes by reducing patient anxiety and proving adequate knowledge about the procedure and possible outcomes to the patient.It also reduces burden on nursing staff and counsellors.Larger and more diverse cohort studies will help us understand the wider application of this tool on the patient population.It may be difficult to apply this tool on elderly patients with failing eyesight,multiple physical comorbidities.Also,there may be reduced acceptance of this modality by older nursing staff and practitioners who may prefer the traditional verbal version for counselling.We will benefit from a combined approach of using virtual reality apps with tradition one-on-one counselling to help alleviate patient concerns and improve patient and healthcare professional satisfaction. 展开更多
关键词 NURSE PATIENT virtual reality COUNSELLING Healthcare
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Application of virtual reality technology improves the functionality of brain networks in individuals experiencing pain
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作者 Takahiko Nagamine 《World Journal of Clinical Cases》 SCIE 2025年第3期66-68,共3页
Medical procedures are inherently invasive and carry the risk of inducing pain to the mind and body.Recently,efforts have been made to alleviate the discomfort associated with invasive medical procedures through the u... Medical procedures are inherently invasive and carry the risk of inducing pain to the mind and body.Recently,efforts have been made to alleviate the discomfort associated with invasive medical procedures through the use of virtual reality(VR)technology.VR has been demonstrated to be an effective treatment for pain associated with medical procedures,as well as for chronic pain conditions for which no effective treatment has been established.The precise mechanism by which the diversion from reality facilitated by VR contributes to the diminution of pain and anxiety has yet to be elucidated.However,the provision of positive images through VR-based visual stimulation may enhance the functionality of brain networks.The salience network is diminished,while the default mode network is enhanced.Additionally,the medial prefrontal cortex may establish a stronger connection with the default mode network,which could result in a reduction of pain and anxiety.Further research into the potential of VR technology to alleviate pain could lead to a reduction in the number of individuals who overdose on painkillers and contribute to positive change in the medical field. 展开更多
关键词 virtual reality PAIN ANXIETY Salience network Default mode network
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A virtual experiment showing single particle motion on a linearly vibrating screen-deck 被引量:11
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作者 ZHAO, Lala LIU, Chusheng YAN, Junxia 《Mining Science and Technology》 EI CAS 2010年第2期276-280,共5页
A virtual sieving experimental simulation system was built using physical simulation principles.The effects of vibration frequency and amplitude,the inclination angle of the screen-deck and the vibration direction ang... A virtual sieving experimental simulation system was built using physical simulation principles.The effects of vibration frequency and amplitude,the inclination angle of the screen-deck and the vibration direction angle of screen on single particle kinematics were predicted.Properties such as the average velocity and the average throw height were studied.The results show that the amplitude and the angle of vibration have a great effect on particle average velocity and average height.The vibration frequency and the screen-deck inclination angle appear to have little influence on these responses.For materials that are difficult to screen the vibration frequency and amplitude,the screen-deck inclination angle and the vibration angle should be set to 14 Hz,6.6 mm,6° and 40°,respectively,to obtain optimal particle kinematics.A screening process can be simulated reliably by means of a virtual experiment and these results provide references for both screening theory research and sieving practice. 展开更多
关键词 linear vibrating screen kinematics parameters single particle throwing motion virtual experiment
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Mental health in the virtual world:Challenges and opportunities in the metaverse era 被引量:3
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作者 Yolanda López del Hoyo Matilde Elices Javier Garcia-Campayo 《World Journal of Clinical Cases》 SCIE 2024年第17期2939-2945,共7页
Current rates of mental illness are worrisome.Mental illness mainly affects females and younger age groups.The use of the internet to deliver mental health care has been growing since 2020 and includes the implementat... Current rates of mental illness are worrisome.Mental illness mainly affects females and younger age groups.The use of the internet to deliver mental health care has been growing since 2020 and includes the implementation of novel mental health treatments using virtual reality,augmented reality,and artificial intelligence.A new three dimensional digital environment,known as the metaverse,has emerged as the next version of the Internet.Artificial intelligence,augmented reality,and virtual reality will create fully immersive,experiential,and interactive online environments in the metaverse.People will use a unique avatar to do anything they do in their“real”lives,including seeking and receiving mental health care.In this opinion review,we reflect on how the metaverse could reshape how we deliver mental health treatment,its opportunities,and its challenges. 展开更多
关键词 Metaverse virtual world Artificial intelligence Mental health virtual reality Augmented reality TECHNOLOGY
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Virtual reality for preoperative patient education: Impact on satisfaction, usability, and burnout from the perspective of new nurses 被引量:3
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作者 Jiyoung Kim Donghyun Kim +1 位作者 Sang-Ha Oh Hyeokjae Kwon 《World Journal of Clinical Cases》 SCIE 2024年第28期6204-6216,共13页
BACKGROUND Traditional paper-based preoperative patient education is a struggle for new nurses and requires extensive training.In this situation,virtual reality technology can help the new nurses.Despite its potential... BACKGROUND Traditional paper-based preoperative patient education is a struggle for new nurses and requires extensive training.In this situation,virtual reality technology can help the new nurses.Despite its potential benefits,there are studies on patient satisfaction but there is limited information on the usability of virtual reality(VR)technology for new nurses in giving preoperative education to patients.AIM To investigate the impact on satisfaction,usability,and burnout of a system using VR technology in preoperative patient education.METHODS The study involved 20 nurses from the plastic surgery ward and 80 patients admitted between April and May 2019.Each nurse taught four patients:Two using traditional verbal education and two using virtual reality.The System Usability Scale,After-Scenario Questionnaire,and Maslach Burnout Inventory(MBI)were employed to evaluate the impact of these education methods.RESULTS The VR education groups showed a statistically higher satisfaction than the traditional verbal education groups.Among the three subscales of the MBI,emotional exhaustion and personal accomplishment improved statistically significantly.VR was also better in terms of usability.CONCLUSION This study suggests VR enhances usability and reduces burnout in nurses,but further research is needed to assess its impact on depersonalization and objective measures like stress and heart rate. 展开更多
关键词 virtual reality Preoperative care Patient education BURNOUT USABILITY SATISFACTION Prospective studies
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Permanent Magnet Temperature Estimation for PMSMs Using Virtual Position-offset Injection 被引量:2
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作者 Beichen Ding Yuting Lu +2 位作者 Kaide Huang Guodong Feng Chunyan Lai 《CES Transactions on Electrical Machines and Systems》 EI CSCD 2024年第1期51-60,共10页
This paper proposes a virtual position-offset injection based permanent magnet temperature estimation approach for permanent magnet synchronous machines(PMSMs). The concept of virtual position-offset injection is math... This paper proposes a virtual position-offset injection based permanent magnet temperature estimation approach for permanent magnet synchronous machines(PMSMs). The concept of virtual position-offset injection is mathematically transforming the machine model to a virtual frame with a position-offset. The virtual frame temperature estimation model is derived to calculate the permanent magnet temperature(PMT) directly from the measurements with computation efficiency. The estimation model involves a combined inductance term, which can simplify the establishment of saturation compensation model with less measurements. Moreover, resistance and inverter distorted terms are cancelled in the estimation model, which can improve the robustness to the winding temperature rise and inverter distortion. The proposed approach can achieve simplified computation in temperature estimation and reduced memory usage in saturation compensation. While existing model-based approaches could be affected by either the need of resistance and inverter information or complex saturation compensation. Experiments are conducted on the test machine to verify the proposed approach under various operating conditions. 展开更多
关键词 PMSM Magnet temperature estimation virtual position offset injection Inverter nonlinearity
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Breaking the optical efficiency limit of virtual reality with a nonreciprocal polarization rotator 被引量:1
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作者 Yuqiang Ding Zhenyi Luo +1 位作者 Garimagai Borjigin Shin-Tson Wu 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第3期4-14,共11页
A catadioptric lens structure,also known as pancake lens,has been widely used in virtual reality(VR)displays to reduce the formfactor.However,the utilization of a half mirror(HM)to fold the optical path thrice leads t... A catadioptric lens structure,also known as pancake lens,has been widely used in virtual reality(VR)displays to reduce the formfactor.However,the utilization of a half mirror(HM)to fold the optical path thrice leads to a significant optical loss.The theoretical maximum optical efficiency is merely 25%.To transcend this optical efficiency constraint while retaining the foldable characteristic inherent to traditional pancake optics,in this paper,we propose a theoretically lossless folded optical system to replace the HM with a nonreciprocal polarization rotator.In our feasibility demonstration experiment,we used a commercial Faraday rotator(FR)and reflective polarizers to replace the lossy HM.The theoretically predicted 100%efficiency can be achieved approximately by using two high-extinction-ratio reflective polarizers.In addition,we evaluated the ghost images using a micro-OLED panel in our imaging system.Indeed,the ghost images can be suppressed to undetectable level if the optics are with antireflection coating.Our novel pancake optical system holds great potential for revolutionizing next-generation VR displays with lightweight,compact formfactor,and low power consumption. 展开更多
关键词 near-eye display virtual reality pancake optics folded optics nonreciprocal polarization rotator
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Prediction of corrosion rate for friction stir processed WE43 alloy by combining PSO-based virtual sample generation and machine learning 被引量:1
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作者 Annayath Maqbool Abdul Khalad Noor Zaman Khan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第4期1518-1528,共11页
The corrosion rate is a crucial factor that impacts the longevity of materials in different applications.After undergoing friction stir processing(FSP),the refined grain structure leads to a notable decrease in corros... The corrosion rate is a crucial factor that impacts the longevity of materials in different applications.After undergoing friction stir processing(FSP),the refined grain structure leads to a notable decrease in corrosion rate.However,a better understanding of the correlation between the FSP process parameters and the corrosion rate is still lacking.The current study used machine learning to establish the relationship between the corrosion rate and FSP process parameters(rotational speed,traverse speed,and shoulder diameter)for WE43 alloy.The Taguchi L27 design of experiments was used for the experimental analysis.In addition,synthetic data was generated using particle swarm optimization for virtual sample generation(VSG).The application of VSG has led to an increase in the prediction accuracy of machine learning models.A sensitivity analysis was performed using Shapley Additive Explanations to determine the key factors affecting the corrosion rate.The shoulder diameter had a significant impact in comparison to the traverse speed.A graphical user interface(GUI)has been created to predict the corrosion rate using the identified factors.This study focuses on the WE43 alloy,but its findings can also be used to predict the corrosion rate of other magnesium alloys. 展开更多
关键词 Corrosion rate Friction stir processing virtual sample generation Particle swarm optimization Machine learning Graphical user interface
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Influence of static cartoons combined with dynamic virtual environments on preoperative anxiety of preschool-aged children undergoing surgery 被引量:1
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作者 Ya-Lin Zhang Qi-Ying Zhou +3 位作者 Peng Zhang Lin-Feng Huang Li Jin Zhi-Guo Zhou 《World Journal of Clinical Cases》 SCIE 2024年第22期4947-4955,共9页
BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons comb... BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons combined with dynamic virtual environments on preoperative anxiety and anesthesia induction compliance in preschool-aged children undergoing surgery.METHODS One hundred and sixteen preschool-aged children were selected and assigned to the drug(n=37),intervention(n=40),and control(n=39)groups.All the children received routine preoperative checkups and nursing before being transferred to the preoperative preparation room on the day of the operation.The drug group received 0.5 mg/kg midazolam and the intervention group treatment consisting of static cartoons combined with dynamic virtual environments.The control group received no intervention.The modified Yale Preoperative Anxiety Scale was used to evaluate the children’s anxiety level on the day before surgery(T0),before leaving the preoperative preparation room(T1),when entering the operating room(T2),and at anesthesia induction(T3).Compliance during anesthesia induction(T3)was evaluated using the Induction Compliance Checklist(ICC).Changes in mean arterial pressure(MAP),heart rate(HR),and respiratory rate(RR)were also recorded at each time point.RESULTS The anxiety scores of the three groups increased variously at T1 and T2.At T3,both the drug and intervention groups had similar anxiety scores,both of which were lower than those in the control group.At T1 and T2,MAP,HR,and RR of the three groups increased.The drug and control groups had significantly higher MAP and RR than the intervention group at T2.At T3,the MAP,HR,and RR of the drug group decreased and were significantly lower than those in the control group but were comparable to those in the intervention group.Both the drug and intervention groups had similar ICC scores and duration of anesthesia induction(T3),both of which were higher than those of the control group.CONCLUSION Combining static cartoons with dynamic virtual environments as effective as medication,specifically midazolam,in reducing preoperative anxiety and fear in preschool-aged children.This approach also improve their compliance during anesthesia induction and helped maintain their stable vital signs. 展开更多
关键词 PRESCHOOL Children Static cartoons combined with dynamic virtual environments Preoperative anxiety COMPLIANCE Anesthesia induction
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Tree: Reducing the use of restrictive practices on psychiatric wards through virtual reality immersive technology training 被引量:1
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作者 Peter Phiri Laura Pemberton +8 位作者 Yang Liu Xiaojie Yang Joe Salmon Isabel Boulter Sana Sajid Jackie Clarke Andy McMillan Jian Qing Shi Gayathri Delanerolle 《World Journal of Psychiatry》 SCIE 2024年第10期1521-1537,共17页
BACKGROUND Restrictive practices(RPs)are defined by measures linked to physical and chemical restraints to reduce the movement or control behaviours during any emergency.Seclusion is an equal part of RPs intended to i... BACKGROUND Restrictive practices(RPs)are defined by measures linked to physical and chemical restraints to reduce the movement or control behaviours during any emergency.Seclusion is an equal part of RPs intended to isolate and reduce the sensory stimulation to safeguard the patient and those within the vicinity.Using interventions by way of virtual reality(VR)could assist with reducing the need for RPs as it could help reduce anxiety or agitation by way of placing users into realistic and immersive environments.This could also aid staff to and change current RPs.AIM To assess the feasibility and effectiveness of using a VR platform to provide reduction in RP training.METHODS A randomised controlled feasibility study,accompanied by evaluations at 1 month and 6 months,was conducted within inpatient psychiatric wards at Southern Health National Health Service Foundation Trust,United Kingdom.Virti VR scenarios were used on VR headsets to provide training on reducing RPs in 3 inpatient psychiatric wards.Outcome measures included general self-efficacy scale,generalised anxiety disorder assessment 7(GAD-7),Burnout Assessment Tool 12,the Everyday Discrimination Scale,and the Compassionate Engagement and Action Scale.RESULTS Findings revealed statistically significant differences between the VR and treatment as usual groups,in the Everyday Discrimination Scale items Q8 and Q9:P=0.023 and P=0.040 respectively,indicating higher levels of perceived discrimination in the VR group.There were no significant differences between groups in terms of general self-efficacy,generalised anxiety disorder assessment 9,and Burnout Assessment Tool 12 scores.A significant difference was observed within the VR group for compassionate engagement from others(P=0.005)over time.Most respondents recorded System Usability Scale scores above 70,with an average score of 71.79.There was a significant reduction in rates of RPs in the VR group vs treatment as usual group with a fluctuating variability observed in the VR group likely due to external factors not captured in the study.CONCLUSION Ongoing advancement of VR technology enables the possibility of creating scenarios and simulations tailored to healthcare environments that empower staff by providing more comprehensive and effective training for handling situations. 展开更多
关键词 virtual reality Restrictive practices Inpatient wards Restraint Isolation Rapid tranquilisation Covert medication Procedural restrictions Health professions training
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Opportunities and Challenges of Virtual Trade Shows Amid the Covid-19 Pandemic-Take China as an Example
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作者 ZHANG Wei 《Sino-US English Teaching》 2022年第2期60-64,共5页
Covid-19 has brought a lot of challenges and difficulties to the world,as well as changes to many industries.In the exhibition industry,virtual trade shows have been booming due to Covid-19.However,with various change... Covid-19 has brought a lot of challenges and difficulties to the world,as well as changes to many industries.In the exhibition industry,virtual trade shows have been booming due to Covid-19.However,with various changes in the world after the outbreak of Covid-19,the situation of the epidemic changes,and the further development of science and technology,Virtual trade shows meet new opportunities and new challenges.The severity of the epidemic in some periods and in some regions did provide a certain impetus for virtual trade shows,but the epidemic tends to be less serious in general,and there is a possibility that the impetus is gradually weakening to some extent.The further development of technology has promoted the upgrading and maturity of virtual trade show,but the immaturity of technology and the side effects discovered after the application of technology have also become the obstacles to the development of virtual trade show. 展开更多
关键词 virtual trade shows OPPORTUNITIES challenges
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Virtual reality tools for training in gastrointestinal endoscopy:A systematic review 被引量:1
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作者 Tuấn Quang Dương Jonathan Soldera 《Artificial Intelligence in Gastrointestinal Endoscopy》 2024年第2期41-54,共14页
BACKGROUND Virtual reality(VR)has emerged as an innovative technology in endoscopy training,providing a simulated environment that closely resembles real-life scenarios and offering trainees a valuable platform to acq... BACKGROUND Virtual reality(VR)has emerged as an innovative technology in endoscopy training,providing a simulated environment that closely resembles real-life scenarios and offering trainees a valuable platform to acquire and enhance their endoscopic skills.This systematic review will critically evaluate the effectiveness and feasibility of VR-based training compared to traditional methods.AIM To evaluate the effectiveness and feasibility of VR-based training compared to traditional methods.By examining the current state of the field,this review seeks to identify gaps,challenges,and opportunities for further research and implementation of VR in endoscopic training.METHODS The study is a systematic review,following the guidelines for reporting systematic reviews set out by the PRISMA statement.A comprehensive search command was designed and implemented and run in September 2023 to identify relevant studies available,from electronic databases such as PubMed,Scopus,Cochrane,and Google Scholar.The results were systematically reviewed.RESULTS Sixteen articles were included in the final analysis.The total number of participants was 523.Five studies focused on both upper endoscopy and colonoscopy training,two on upper endoscopy training only,eight on colonoscopy training only,and one on sigmoidoscopy training only.Gastrointestinal Mentor virtual endoscopy simulator was commonly used.Fifteen reported positive results,indicating that VR-based training was feasible and acceptable for endoscopy learners.VR technology helped the trainees enhance their skills in manipulating the endoscope,reducing the procedure time or increasing the technical accuracy,in VR scenarios and real patients.Some studies show that the patient discomfort level decreased significantly.However,some studies show there were no significant differences in patient discomfort and pain scores between VR group and other groups.CONCLUSION VR training is effective for endoscopy training.There are several well-designed randomized controlled trials with large sample sizes,proving the potential of this innovative tool.Thus,VR should be more widely adopted in endoscopy training.Furthermore,combining VR training with conventional methods could be a promising approach that should be implemented in training. 展开更多
关键词 virtual reality Gastrointestinal endoscopy Systematic review virtual reality training SIMULATION
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Spatial Heterogeneity of Embedded Water Consumption from the Perspective of Virtual Water Surplus and Deficit in the Yellow River Basin,China
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作者 MA Weijing LI Xiangjie +1 位作者 KOU Jingwen LI Chengyi 《Chinese Geographical Science》 SCIE CSCD 2024年第2期311-326,共16页
Virtual water trade(VWT)provides a new perspective for alleviating water crisis and has thus attracted widespread attention.However,the heterogeneity of virtual water trade inside and outside the river basin and its i... Virtual water trade(VWT)provides a new perspective for alleviating water crisis and has thus attracted widespread attention.However,the heterogeneity of virtual water trade inside and outside the river basin and its influencing factors remains further study.In this study,for better investigating the pattern and heterogeneity of virtual water trade inside and outside provincial regions along the Yellow River Basin in 2015 using the input-output model(MRIO),we proposed two new concepts,i.e.,virtual water surplus and virtual water deficit,and then used the Logarithmic Mean Divisia Index(LMDI)model to identify the inherent mechanism of the imbalance of virtual water trade between provincial regions along the Yellow River Basin and the other four regions in China.The results show that:1)in provincial regions along the Yellow River Basin,the less developed the economy was,the larger the contribution of the agricultural sector in virtual water trade,while the smaller the contribution of the industrial sector.2)Due to the large output of agricultural products,the upstream and midstream provincial regions of the Yellow River Basin had a virtual water surplus,with a net outflow of virtual water of 2.7×10^(8) m^(3) and 0.9×10^(8) m^(3),respectively.3)provincial regions along the Yellow River Basin were in a virtual water deficit with the rest of China,and the decisive factor was the active degree of trade with the outside.This study would be beneficial to illuminate the trade-related water use issues in provincial regions along the Yellow River Basin,which has farreaching practical signific-ance for alleviating water scarcity. 展开更多
关键词 virtual water trade(VWT) input-output model(MRIO) virtual water surplus virtual water deficit Yellow River Basin China
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Wear dependent virtual flow rate sensor for progressing cavity pumps with deformable stator
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作者 Jens Müller Sebastian Leonow +2 位作者 Johannes Schulz Christian Hansen Martin Monnigmann 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1346-1353,共8页
This contribution presents a novel wear dependent virtual flow rate sensor for single stage single lobe progressing cavity pumps. We study the wear-induced material loss of the pump components and the impact of this m... This contribution presents a novel wear dependent virtual flow rate sensor for single stage single lobe progressing cavity pumps. We study the wear-induced material loss of the pump components and the impact of this material loss on the volumetric efficiency. The results are combined with an established backflow model to implement a backflow calculation procedure that is adaptive to wear. We use a laboratory test setup with a highly abrasive fluid and operate a pump from new to worn condition to validate our approach. The obtained measurement data show that the presented virtual sensor is capable of calculating the flow rate of a pump being subject to wear during its regular operation. 展开更多
关键词 BACKFLOW Progressing cavity pump virtual sensor WEAR
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Characterization of a Powertrain Test Bed in the Context of Virtual Validation of Drivability
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作者 Schmidt HENRIK Prokop GÜNTHER 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第S01期9-19,共11页
Technological trends in the automotive industry toward a software-defined and autonomous vehicle require a reassessment of today’s vehicle development process.The validation process soaringly shapes after starting wi... Technological trends in the automotive industry toward a software-defined and autonomous vehicle require a reassessment of today’s vehicle development process.The validation process soaringly shapes after starting with hardware-in-the-loop testing of control units and reproducing real-world maneuvers and physical interaction chains.Here,the road-to-rig approach offers a vast potential to reduce validation time and costs significantly.The present research study investigates the maneuver reproduction of drivability phenomena at a powertrain test bed.Although drivability phenomena occur in the frequency range of most up to 30∙Hz,the design and characteristics substantially impact the test setup’s validity.By utilization of modal analysis,the influence of the test bed on the mechanical characteristic is shown.Furthermore,the sensitivity of the natural modes of each component,from either specimen or test bed site,is determined.In contrast,the uncertainty of the deployed measurement equipment also affects the validity.Instead of an accuracy class indication,we apply the ISO/IEC Guide 98 to the measurement equipment and the test bed setup to increase the fidelity of the validation task.In conclusion,the present paper contributes to a traceable validity determination of the road-to-rig approach by providing objective metrics and methods. 展开更多
关键词 powertrain test bed virtual validation modal analysis powertrain-hardware-in-the-loop DRIVABILITY measurement uncertainty
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An Effective 3D-CFD Methodology for the Complementary Virtual Development of Alternative Fuels and Engine Concepts
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作者 Robin SCHMELCHER Thomas GAL +6 位作者 Mario PIPOLO Cristian TORTORELLA Antonino VACCA Edoardo ROSSI Francesco CUPO Marco CHIODI AndréCASAL KULZER 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第S01期1-8,共8页
With the aim of reducing the cost of developing internal combustion engines,while at the same time investigating different geometries,layouts and fuels,3D-CFD-CHT simulations represent an indispensable part for the de... With the aim of reducing the cost of developing internal combustion engines,while at the same time investigating different geometries,layouts and fuels,3D-CFD-CHT simulations represent an indispensable part for the development of new technologies.These tools are increasingly used by manufacturers,as a screening process before building the first prototype.This paper presents an innovative methodology for virtual engine development.The 3D-CFD tool QuickSim,developed at FKFS,allows both a significant reduction in computation time and an extension of the simulated domain for complete engine systems.This is possible thanks to a combination of coarse meshes and self-developed internal combustion engine models,which simultaneously ensure high predictability.The present work demonstrates the capabilities of this innovative methodology for the design and optimization of different engines and fuels with the goal of achieving the highest possible combustion efficiencies and pollutant reductions.The analysis focuses on the influence of different fuels such as hydrogen,methanol,synthetic gasolines and methane on different engine geometries,in combination with suitable injection and ignition systems,including passive and active pre-chambers.Lean operations as well as knock reduction are discussed,particularly for methane and hydrogen injection.Finally,it is shown how depending on the chosen fuel,an appropriate ad-hoc engine layout can be designed to increase the indicated efficiency of the respective engines. 展开更多
关键词 eFuels METHANE METHANOL hydrogen CO_(2)reduction virtual development 3D-CFD
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A virtual thermometer for ultrahigh-temperature-pressure experiments in a large-volume press
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作者 Bingtao Feng Longjian Xie +8 位作者 Xuyuan Hou Shucheng Liu Luyao Chen Xinyu Zhao Chenyi Li Qiang Zhou Kuo Hu Zhaodong Liu Bingbing Liu 《Matter and Radiation at Extremes》 SCIE EI CSCD 2024年第4期98-110,共13页
Ultrahigh-temperature-pressure experiments are crucial for understanding the physical and chemical properties of matter.The recent development of boron-doped diamond(BDD)heaters has made such melting experiments possi... Ultrahigh-temperature-pressure experiments are crucial for understanding the physical and chemical properties of matter.The recent development of boron-doped diamond(BDD)heaters has made such melting experiments possible in large-volume presses.However,estimates of temperatures above 2600 K and of the temperature distributions inside BDD heaters are not well constrained,owing to the lack of a suitable thermometer.Here,we establish a three-dimensional finite element model as a virtual thermometer to estimate the temperature and temperature field above 2600 K.The advantage of this virtual thermometer over those proposed in previous studies is that it considers both alternating and direct current heating modes,the actual sizes of cell assemblies after compression,the effects of the electrode,thermocouple and anvil,and the heat dissipation by the pressure-transmitting medium.The virtual thermometer reproduces the power-temperature relationships of ultrahigh-temperature-pressure experiments below 2600 K at press loads of 2.8-7.9 MN(~19 to 28 GPa)within experimental uncertainties.The temperatures above 2600 K predicted by our virtual thermometer are within the uncertainty of those extrapolated from power-temperature relationships below 2600 K.Furthermore,our model shows that the temperature distribution inside a BDD heater(19-26 K/mm along the radial direction and<83 K/mm along the longitudinal direction)is more homogeneous than those inside conventional heaters such as graphite or LaCrO_(3) heaters(100-200 K/mm).Our study thus provides a reliable virtual thermometer for ultrahigh-temperature experiments using BDD heaters in Earth and material sciences. 展开更多
关键词 virtual ultrahigh SIZES
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Proposal for a realtime Einstein-synchronization-defined satellite virtual clock
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作者 严晨皓 汤雪逸 +4 位作者 王时光 孟李皎悦 孙海媛 何奕彬 王力军 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期268-276,共9页
Realization of high performance satellite onboard clock is vital for various positioning, navigation, and timing applications. For further improvement of the synchronization-based satellite time and frequency referenc... Realization of high performance satellite onboard clock is vital for various positioning, navigation, and timing applications. For further improvement of the synchronization-based satellite time and frequency references, we propose a geosynchronous(GEO) satellite virtual clock concept based on ground–satellite synchronization and present a beacon transponder structure for its implementation(scheduled for launch in 2025), which does not require atomic clocks to be mounted on the satellite. Its high performance relies only on minor modifications to the existing transponder structure of GEO satellites. We carefully model the carrier phase link and analyze the factors causing link asymmetry within the special relativity. Considering that performance of such synchronization-based satellite clocks is primarily limited by the link's random phase noise, which cannot be adequately modeled, we design a closed-loop experiment based on commercial GEO satellites for pre-evaluation. This experiment aims at extracting the zero-means random part of the ground-satellite Ku-band carrier phase via a feedback loop. Ultimately, we obtain a 1σ value of 0.633 ps(two-way link), following the Gaussian distribution. From this result, we conclude that the proposed real-time Einstein-synchronization-defined satellite virtual clock can achieve picosecond-level replication of onboard time and frequency. 展开更多
关键词 Einstein synchronization satellite virtual clock geosynchronous satellite carrier phase
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Special Vehicle Target Detection and Tracking Based on Virtual Simulation Environment and YOLOv5-Block+DeepSort Algorithm
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作者 Mingyuan Zhai Hanquan Zhang +3 位作者 Le Wang Dong Xiao Zhengmin Gu Zhenni Li 《Computers, Materials & Continua》 SCIE EI 2024年第11期3241-3260,共20页
In the process of dense vehicles traveling fast,there will be mutual occlusion between vehicles,which will lead to the problem of deterioration of the tracking effect of different vehicles,so this paper proposes a res... In the process of dense vehicles traveling fast,there will be mutual occlusion between vehicles,which will lead to the problem of deterioration of the tracking effect of different vehicles,so this paper proposes a research method of virtual simulation video vehicle target tracking based on you only look once(YOLO)v5s and deep simple online and realtime tracking(DeepSort).Given that the DeepSort algorithm is currently the most effective tracking method,this paper merges the YOLOv5 algorithm with the DeepSort algorithm.Then it adds the efficient channel attention networks(ECA-Net)focusing mechanism at the back for the cross-stage partial bottleneck with 3 convolutions(C3)modules about the YOLOv5 backbone network and before the up-sampling of the Neck feature pyramid.The YOLOv5 algorithm adopts expected intersection over union(EIOU)instead of complete intersection over union(CIOU)as the loss function of the target frame regression.The improved YOLOv5 algorithm is named YOLOv5-Block.The experimental results show that in the special vehicle target detection(TD)and tracking in the virtual simulation environment,The YOLOv5-Block algorithm has an average accuracy(AP)of 99.5%,which significantly improves the target recognition correctness for typical occlusion cases,and is 1.48 times better than the baseline algorithm.After the virtual simulation video sequence test,multiple objects tracking accuracy(MOTA)and various objects tracking precision(MOTP)improved by 10.7 and 1.75 percentage points,respectively,and the number of vehicle target identity document(ID)switches decreased.Compared with recent mainstream vehicle detection and tracking models,the YOLOv5-Block+Deepsort algorithm can accurately and continuously complete the detection and tracking tasks of special vehicle targets in different scenes. 展开更多
关键词 YOLOv5 DeepSort virtual simulation attention mechanism
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Effects of virtual agents on interaction efficiency and environmental immersion in MR environments
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作者 Yihua BAO Jie GUO +2 位作者 Dongdong WENG Yue LIU Zeyu TIAN 《虚拟现实与智能硬件(中英文)》 EI 2024年第2期169-179,共11页
Background Physical entity interactions in mixed reality(MR)environments aim to harness human capabilities in manipulating physical objects,thereby enhancing virtual environment(VEs)functionality.In MR,a common strate... Background Physical entity interactions in mixed reality(MR)environments aim to harness human capabilities in manipulating physical objects,thereby enhancing virtual environment(VEs)functionality.In MR,a common strategy is to use virtual agents as substitutes for physical entities,balancing interaction efficiency with environmental immersion.However,the impact of virtual agent size and form on interaction performance remains unclear.Methods Two experiments were conducted to explore how virtual agent size and form affect interaction performance,immersion,and preference in MR environments.The first experiment assessed five virtual agent sizes(25%,50%,75%,100%,and 125%of physical size).The second experiment tested four types of frames(no frame,consistent frame,half frame,and surrounding frame)across all agent sizes.Participants,utilizing a head mounted display,performed tasks involving moving cups,typing words,and using a mouse.They completed questionnaires assessing aspects such as the virtual environment effects,interaction effects,collision concerns,and preferences.Results Results from the first experiment revealed that agents matching physical object size produced the best overall performance.The second experiment demonstrated that consistent framing notably enhances interaction accuracy and speed but reduces immersion.To balance efficiency and immersion,frameless agents matching physical object sizes were deemed optimal.Conclusions Virtual agents matching physical entity sizes enhance user experience and interaction performance.Conversely,familiar frames from 2D interfaces detrimentally affect interaction and immersion in virtual spaces.This study provides valuable insights for the future development of MR systems. 展开更多
关键词 Mixed reality virtual agents Interaction performance Environmental immersion virtual environments
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