Virtual Wall Research Articles

USE OF KAHOOT! AND JAMBOARD FOR THE REALIZATION AND ORGANIZATION OF CREATIVE SCHOOL ACTIVITIES DURING THE COVID-19 PANDEMIC

This mixed study analyzes the students’ perception about the use of Kahoot! and Jamboard in the teaching–learning process about the English language during the COVID-19 pandemic through data science. Kahoot! is a web tool that facilitates and promotes the participation between the educator and students through the realization of digital games and Jamboard is a virtual wall that allows the active role through the dissemination of information and exchange of ideas. The participants are 30 students of Design and Visual Communication who took the English Language course in the distance modality at the National Autonomous University of Mexico, Mexico, during the 2020 school year. The results of the machine learning technique indicate that the realization of digital games in Kahoot! and the dissemination and exchange of information in Jamboard positively influence the motivation, assimilation of knowledge and participation of the students during the Verbs Unit. Data science identified 6 predictive models on the use of these technological tools in the educational process about the English language through the decision tree technique. Finally, educators have the opportunity to create new virtual spaces and promote the active role of the students by incorporating Kahoot! and Jamboard in the school activities during the COVID-19 pandemic.

A study of the simulated climatological January mean upwelling in the northwestern Gulf of Alaska

In this research, we studied the upwelling in the northwestern Gulf of Alaska using the climatological January mean and data from the output of the Ocean General Circulation Model for Earth Simulator (OFES2). Specifically, we analyzed the upwelling in the regions where the Alaska Coastal Current (ACC) flows out of the Shelikof Strait (especially the part to the west of Kodiak Island) and where the ACC and the Alaskan Stream (AS) are confluent. In both regions, strong geostrophic currents and downwelling-favorable wind predominate in winter. Furthermore, there are freshwater discharges along the Alaskan coast and an observed mean current vertical shear in the ACC. We revealed that when the internal water stress is larger than the wind stress inside the study regions, this could be decisive in terms of the local horizontal velocity divergence and further upwelling, even if the region is away from the coast and lacks upwelling-favorable wind conditions. Geostrophic stress is part of the internal water stress and is a product of the geostrophic current shear (due to the thermal wind relation) and the vertical viscosity coefficient. The analysis indicated that a front with a large geostrophic stress may act as a “virtual wall” and contribute to local upwelling within a depth of approximately 100 m in the study regions. This process could provide a heuristic for understanding the distribution of pollock in the areas during February and March, which corresponds to the simulated upwelling region.

Modeling and Control of a 5-DOF Parallel Continuum Haptic Device

In this article, we propose a new continuum robotics approach for haptic rendering and comanipulation. This approach is illustrated using a robotic interface with six motorized fixed axes connected by deformable beams, in parallel, to an end effector with 5 degrees of freedom. Apart from the rotation of the motors, this design has no articulation, and the motion of the end effector is achieved by deformation of the beams. The flexible beams are equipped with bending sensors, and the motors have encoders. We use a nonlinear finite element mechanical model of the robot based on a mesh of beam elements that is computed in real time at 20 Hz. The bending sensors are incorporated into the model, which allows us to obtain an accurate estimate of the force exerted by the user on the end effector. The model enables a new methodology for calculating the workspace of the continuum haptic device. The model also is propagated to a higher frequency loop (500 Hz), which performs sensing and control of the robot at high rates, using an admittance-type control to command new positions of the actuators. We show that this control methodology allows haptic rendering of virtual walls that are stiffer than the natural stiffness of the robot. Finally, we demonstrate the use of the device for simple comanipulation tasks.

Generalizing the optic flow equalization control law to an asymmetrical person-plus-object system.

Visually guided action in humans occurs in part through the use of control laws, which are dynamical equations in which optical information modulates an actor's interaction with their environment. For example, humans locomote through the center of a corridor by equalizing the speed of optic flow across their left and right fields of view. This optic flow equalization control law relies on a crucial assumption: that the shape of the body relative to the eyes is laterally symmetrical. Humans engaging in tool use are often producing person-plus-object systems that are not laterally symmetrical, such as when they hold a tool, bag, or briefcase in one hand, or when they drive a vehicle. This experiment tests a new generalized control law for centered steering that accounts for asymmetries produced by external tool use. Participants held an asymmetrical bar and centered themselves within a virtual moving hallway while the speed of the virtual walls were systematically changed. The results demonstrate that humans engaging with an asymmetrical tool can (1) perceive the asymmetry of a person-plus-object system, (2) use that information to modulate the use of optic flow equalization control laws for centered steering, and (3) functionally incorporate the asymmetrical tool into their perception-action system to successfully navigate their environment.

A New Young Wall Realization of B ( λ ) and B ( ∞ )

Using new combinatorics of Young walls, we give a new construction of the arbitrary level highest weight crystal [Formula: see text] for the quantum affine algebras of types [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]. We show that the crystal consisting of reduced Young walls is isomorphic to the crystal [Formula: see text]. Moreover, we provide a new realization of the crystal [Formula: see text] in terms of reduced virtual Young walls and reduced extended Young walls.

The NEFFIE project: Technological innovation, artistic co-creation and social augmented experience

This article presents the NEFFIE (which stands for ‘Neuroaesthetic Photography’) project, a contemporary reinterpretation of Franco Vaccari’s iconic artwork, presented 50 years ago at the 1972 International Venice Art Biennale and entitled Exhibition in Real Time No. 4: Leave on the Walls a Photographic Trace of Your Fleeting Visit. Thanks to today’s technological innovation, NEFFIE develops Vaccari’s idea from a more contemporary perspective. Vaccari’s original photo booth becomes a technologically revisited booth that uses an algorithm and wearable sensors to reshape the subjective emotional-cognitive responses derived from viewing particular images, thus generating the ‘cognitive photograph’ or ‘COFFIE metapicture’. These metapictures are subsequently minted as NFTs (non-fungible tokens) objects and then displayed on a virtual wall, the ‘COFFIE wall’, generating what can be defined as a Virtual Exhibition in Real Time, a hypothetical contemporary re-actualization of Vaccari’s artistic proposition. The NEFFIE project could be considered a pervasive media art proposal capable of promoting social cohesion, by encouraging creative participation and co-creation. The project is being developed in Milan, thanks to a fruitful interdisciplinary collaboration between the Research Center in Advanced Technology in Health and Well-Being of San Raffaele Hospital, and ICONE, the European Research Center in History and Theory of the Image of Vita-Salute San Raffaele University. This multidisciplinary approach combines art-historical theoretical thinking with the world of technological innovation. In particular, the NEFFIE project integrates the visual and conceptual tools of photography with the methodologies and knowledge of biomedical engineering and computer science.

Enhancing manufacturing education based on controller-free augmented reality learning

Based on several exemplary use-cases, the technological limits as well as the educational impact of controller-free Augmented Reality learning, using the Microsoft HoloLens 2, were investigated. The field of application was manufacturing engineering, and here in particular, the aluminum extrusion process. Compared to traditional learning environments, such as lectures and exercises, the developed test environments included the additional use of learning setups at the actual forming machine in the laboratory, enhanced by Augmented Reality. A total of 12 students from various academic years participated in the impact analysis study. The study comprised a general survey regarding various aspects of the controller-free learning, including visual and acoustic appearance of the developed scenarios as well as details regarding the control of the augmented objects. It was found that, even though none of the students had used such a device before, interacting with the holograms by hand, and not through controllers, was intuitive for the majority of students. In contrast, the interaction mode for long distances, the hand ray control mode, was assessed as unintuitive and frustrating at times. The visual and acoustic quality of the developed applications was rated high and sufficient for the use in education and production environments. Specific features developed for the extrusion press application, such as the display of Finite-Element-Simulation results, kinematic process animations, live sensor data through webservers and virtual safety walls were regarded as fundamental for the beneficial use of Augmented Reality in education and production. Based on the findings, future Augmented Reality applications in the field of manufacturing education can improve in usability and acceptance by engineering students without prior testing.

An assistant algorithm model for a mobile robot to pass through a concave obstacle area

When a mobile robot passes through a concave obstacle area, the limitations of the traditional control algorithm add a significant challenge to the mobile robot to move through the concave obstacle area efficiently. Improving the conventional path planning algorithm is a common choice to solve this problem. However, because various path planning algorithms adapt to the fixed scene and the algorithm steps are complex, it is difficult to popularize these algorithms. In addition, conventional path planning algorithms usually encounter difficulties when passing through recessed obstacle areas or cause robot deadlock. An auxiliary algorithm strategy is proposed to help mobile robots avoid concave obstacles quickly. The algorithm strategy plays an auxiliary role by incorporating the judgment of the starting position of the mobile robot, the building of a virtual wall to shield the concave obstacle area, and the judgment of the moving direction of the mobile robot. The advantage of this algorithm strategy is that it does not change the operation mechanism of traditional path-planning algorithms and is highly adaptable. The results of the comparison of simulation experiments with the APF (Artificial Potential Field), the ACO (Ant Colony Optimization), the RRT (Rapidly-Exploring Random Trees), the A-star algorithm, and the Dijkstra algorithm show the inclusion of the auxiliary algorithm strategy resulted in a significant increase in the efficiency of the mobile robot through the depressed obstacle zone.Article Highlights●This auxiliary algorithm strategy can avoid the self-locking caused by the mobile robot falling into the concave obstacle area.●This auxiliary algorithm strategy does not change the mechanism of the traditional path planning algorithm, and it is simple and easy to be used.●This auxiliary algorithm has wide adaptability (it can assist the mainstream path planning algorithm and adapt to various scenarios).

A Large Force Haptic Interface with Modular Linear Actuators

This paper presents a haptic interface with modular linear actuators that addresses the limitations of conventional devices based on rotary joints. The proposed haptic interface is composed of parallel linear actuators that provide high backdrivability and small inertia. The performance of the haptic interface is compared to those of conventional mechanisms in terms of force capability, reflected inertia, and structural stiffness. High stiffness, large range of motion, and high force capability, which are in trade-off relationships in traditional haptic interfaces, are achieved. The device can apply up to 83 N continuously, i.e., three-fold more than most haptic devices. The theoretical minimum haptic force density and stiffness of the proposed mechanism are 1.3 to 1.9 and 37 times those of the conventional mechanisms under similar conditions, respectively. The system is scalable because the structural stiffness depends on only the timing belt stiffness, whereas that of conventional haptic interfaces is inversely proportional to the cube of the structural length. The modular actuator enables changes in the degrees of freedom (DOFs) for different applications. The proposed haptic interface was tested through an interaction experiment in a virtual environment with virtual walls.

Перспективные технологии визуализации опасностей

Purpose: To identify the most prospective technologies for visualizing potential hazards to warn workers in production, including railway transport, as well as any person in everyday life. Methods: Search and comparative analysis of information about new technologies for visualizing hazards in various areas of life to determine the possibility and expediency of their wider implementation. Results: A review and evaluation of existing methods and systems for alerting individuals to hazards, including technologies that have emerged in recent years, such as safety marker lights (BlueSpot and RedSpot, Red Line and Blue Line), GOBO projectors, Slide-mapping technology, Fogscreen, or aerosol screens, virtual or digital walls. Practical significance: The conducted assessment of the advantages and disadvantages of certain hazard visualization technologies will allow for a more reasonable choice of the most advanced systems for a particular field of activity and will contribute to their implementation in practice.

A robotic system for solo surgery in flexible ureteroscopy: development and evaluation with clinical users

PurposeThe robotic system CoFlex for kidney stone removal via flexible ureteroscopy (fURS) by a single surgeon (solo surgery, abbreviated SSU) is introduced. It combines a versatile robotic arm and a commercially available ureteroscope to enable gravity compensation and safety functions like virtual walls. The haptic feedback from the operation site is comparable to manual fURS, as the surgeon actuates all ureteroscope DoF manually.MethodsThe system hardware and software as well as the design of an exploratory user study on the simulator model with non-medical participants and urology surgeons are described. For each user study task both objective measurements (e.g., completion time) and subjective user ratings of workload (using the NASA-TLX) and usability (using the System Usability Scale SUS) were obtained.ResultsCoFlex enabled SSU in fURS. The implemented setup procedure resulted in an average added setup time of 341.7 ± 71.6 s, a NASA-TLX value of 25.2 ± 13.3 and a SUS value of 82.9 ± 14.4. The ratio of inspected kidney calyces remained similar for robotic (93.68 %) and manual endoscope guidance (94.74 %), but the NASA-TLX values were higher (58.1 ± 16.0 vs. 48.9 ± 20.1) and the SUS values lower (51.5 ± 19.9 vs. 63.6 ± 15.3) in the robotic scenario. SSU in the fURS procedure increased the overall operation time from 1173.5 ± 355.7 s to 2131.0 ± 338.0 s, but reduced the number of required surgeons from two to one.ConclusionsThe evaluation of CoFlex in a user study covering a complete fURS intervention confirmed the technical feasibility of the concept and its potential to reduce surgeon working time. Future development steps will enhance the system ergonomics, minimize the users’ physical load while interacting with the robot and exploit the logged data from the user study to optimize the current fURS workflow.

26.2: Fast‐response liquid crystal devices with virtual walls for VR/AR applications

We report the switching mechanism and new electrode design for fast‐response VA‐FFS LC mode with virtual‐wall effect. This virtual wall effect has been actively employed and developed for enhancing the switching speed of LC devices in VR/AR applications in recent years.

An impact sensitivity assessment method of spacecraft based on virtual exterior wall

The impact sensitivity assessment of spacecraft is to obtain the probability of spacecraft encountering the OD/M (orbital debris or meteoroid), which is a prerequisite for survivability assessment of on-orbit spacecraft. An impact sensitivity assessment method of spacecraft based on virtual exterior wall was proposed to improve the computational efficiency. This method eliminates determination of the outermost surface elements of the spacecraft before generating the debris rays, which are assumed to originate from a non-concave virtual wall that completely wraps the spacecraft. The DistMesh method was adopted for the generating of the virtual wall to ensure its mesh quality. The influences of the sizes, mesh densities, shapes of the virtual wall on the efficiency and accuracy were considered to obtain the best combination of the size and mesh density of the wall and spacecraft. The results of this method were compared with those of S3DE (Survivability of Spacecraft in Space Debris Environment), BUMPER, MDPANTO, ESABASE2/Debris to verify the feasibility of the method. The PCHIP (Piecewise Cubic Hermite Interpolating Polynomial) was used to fit the size vs. flux relationship of the space debris to acquire the impact probability of OD/M with arbitrary size on the spacecraft.

A Metaphorical Analysis of Mentoring for Education without Walls in Palestine and Finland with the OLIVE International Project as a Key Example

Nowadays, efforts are being made in Finland to develop education across borders through projects that seek to deal with global learning crises. Palestine, being engaged in high-intensity struggle and faced with emergencies in education, is one example of such an initiative. Both actual and virtual walls exist in the collaboration between Palestinian and Finnish universities. By using conceptual metaphor theory and Ricoeur’s metaphor theory, this paper discusses and analyzes metaphors that emerge in the process of building education without walls in the OLIVE international project. Project activities support online teaching and learning methods. Drawing from the experience of first-stage implementation, the paper brings forward metaphors that emerge in developing mentoring. The study explores new perspectives on mentoring to conceptualize the metaphor by considering the need to decolonize engagement with learning through both intellectual and embodied–affective elements. This is done by providing a framework for immersive learning. As a result, one can conclude that mentoring is not only cognitive but also an embodied metaphor with affective elements and needs immersive learning environments. Mentoring is fluid, as the roles of mentors and mentees interchange and intertwine. Mentoring takes place in groups, between and among peers, students, teachers, and researchers both on-line and on-site.

Achieving gender equality in seafaring: an analysis of stakeholders' suggestions

PurposeThis paper examines the changes suggested by maritime stakeholders to achieve gender equality in seafaring, a male-dominated profession.Design/methodology/approachAdopting a four-stage career cycle framework, this paper analyzes changes proposed by 423 industry stakeholders to promote gender equality in seafaring. These proposed changes were posted on the Day of Seafarers 2019 virtual wall set up by the International Maritime Organization, which served as a forum for industry stakeholders from all over the world to voice their opinions and suggestions.FindingsThe data analysis shows that the suggested changes reflect many challenges and barriers women seafarers face. While stakeholders from Organisation for Economic Co-operation and Development (OECD) countries are more likely to call for changes to remove barriers in the retention and development stage, gender equality in seafaring in non-OECD countries is still seriously hindered by barriers in the recruitment stage. The paper also reveals that comparatively male stakeholders are less likely to appreciate the problems women seafarers face.Originality/valueThis paper takes a comparative approach, comparing the changes proposed by seafarers and other industry stakeholders from different parts of the world. This approach provides a nuanced understanding of issues related to gender equality in seafaring by showing that stakeholders from different backgrounds have different priorities.

Fencing the Desert: Contexts and Politics of the Gulf Border Walls

ABSTRACT The borders of the Gulf states reflect neither historical development nor equitable demographic and geographic distribution. Rather, they were mainly generated by colonial powers for political and economic purposes. This artificial delimitation created new national identities and left many territorial disputes between the Gulf states and their neighbors, which still affect their bilateral relations and the regional subsystem. Security threats and suspicious relations between the Gulf countries have prompted them to unilaterally secure their borders with physical and virtual walls. The first border wall in the Gulf was erected by Kuwait after its liberation from the Iraqi invasion in 1991. After that, the number of border walls in the region has doubled. Today, the Gulf is the most walled region in the world. It is, in fact, a complex border fencing that applies to both external and internal regional borders. In addition to security and political reasons, these walls reflect how these borders were created and how the gulf states themselves were established. Despite the large expenditures on these border fortifications, their effectiveness in achieving security remains controversial.

Thermal Analysis of Turbine Blades with Thermal Barrier Coatings Using燰irtual Wall Thickness Method

A virtual wall thickness method is developed to simulate the temperature field of turbine blades with thermal barrier coatings (TBCs), to simplify the modeling process and improve the calculation efficiency. The results show that the virtual wall thickness method can improve the mesh quality by 20%, reduce the number of meshes by 76.7% and save the calculation time by 35.5%, compared with the traditional real wall thickness method. The average calculation error of the two methods is between 0.21% and 0.93%. Furthermore, the temperature at the blade leading edge is the highest and the average temperature of the blade pressure surface is higher than that of the suction surface under a certain service condition. The blade surface temperature presents a high temperature at both ends and a low temperature in the middle height when the temperature of incoming gas is uniform and constant. The thermal insulation effect of TBCs is the worst near the air film hole, and the best at the blade leading edge. According to the calculated temperature field of the substrate-coating system, the highest thermal insulation temperature of the TC layer is 172.01 K, and the thermal insulation proportions of TC, TGO and BC are 93.55%, 1.54% and 4.91%, respectively.

Wideband band-notched monopulse antenna design utilizing differential mode and common mode radiations

This letter proposes a dual-port wideband monopulse Vivaldi antenna based on a new perspective of common mode and differential mode radiations. To realize the sum and difference patterns utilizing the differential and common mode radiations, a metallic wedge is introduced in the center of the Vivaldi antenna, the effect of the virtual magnetic wall disappears, and the realistic electric wall plays the dominant role, fulfilling the boundary condition for difference beam under common mode excitation. Meanwhile, the sum beam is kept unchanged under differential mode excitation. The desired sum and difference radiation patterns are realized in a single Vivaldi antenna under differential mode and common mode excitations, respectively. Moreover, a notched band is introduced for interference suppression, and the notched frequency can be easily controlled by adjusting the microstrip feeding stub without loading an extra resonator. Measured results show that the proposed monopulse antenna exhibits 101 % fractional bandwidth from 2.2 GHz to 6.7 GHz, in which a notched band is from 3.75 GHz to 4.3 GHz. Across the operational band, the average gain of the sum pattern is 8 dBi, and the null depth of the difference pattern is below −15 dB. Measured results agree well with the simulated ones.

Rolling microswarms along acoustic virtual walls

Rolling is a ubiquitous transport mode utilized by living organisms and engineered systems. However, rolling at the microscale has been constrained by the requirement of a physical boundary to break the spatial homogeneity of surrounding mediums, which limits its prospects for navigation to locations with no boundaries. Here, in the absence of real boundaries, we show that microswarms can execute rolling along virtual walls in liquids, impelled by a combination of magnetic and acoustic fields. A rotational magnetic field causes individual particles to self-assemble and rotate, while the pressure nodes of an acoustic standing wave field serve as virtual walls. The acoustic radiation force pushes the microswarms towards a virtual wall and provides the reaction force needed to break their fore-aft motion symmetry and induce rolling along arbitrary trajectories. The concept of reconfigurable virtual walls overcomes the fundamental limitation of a physical boundary being required for universal rolling movements.

Low-Cost UVBot Using SLAM to Mitigate the Spread of Noroviruses in Occupational Spaces.

Noroviruses (NoVs) cause over 90% of non-bacterial gastroenteritis outbreaks in adults and children in developed countries. Therefore, there is a need for approaches to mitigate the transmission of noroviruses in workplaces to reduce their substantial health burden. We developed and validated a low-cost, autonomous robot called the UVBot to disinfect occupational spaces using ultraviolet (UV) lamps. The total cost of the UVBOT is less than USD 1000, which is much lower than existing commercial robots that cost as much as USD 35,000. The user-friendly desktop application allows users to control the robot remotely, check the disinfection map, and add virtual walls to the map. A 2D LiDAR and a simultaneous localization and mapping (SLAM) algorithm was used to generate a map of the space being disinfected. Tulane virus (TV), a human norovirus surrogate, was used to validate the UVBot's effectiveness. TV was deposited on a painted drywall and exposed to UV radiation at different doses. A 3-log (99.9%) reduction of TV infectivity was achieved at a UV dose of 45 mJ/cm2. We further calculated the sanitizing speed as 3.5 cm/s and the efficient sanitizing distance reached up to 40 cm from the UV bulb. The design, software, and environment test data are available to the public so that any organization with minimal engineering capabilities can reproduce the UVBot system.