Effects of Character Guide in Immersive Virtual Reality Stories

Bringing cinematic experiences from traditional film screens into Virtual Reality (VR) has become an increasingly popular form of entertainment in recent years. VR provides viewers unprecedented film experience that allows them to freely explore around the environment and even interact with virtual props and characters. For the audience, this kind of experience raises their sense of presence in a different world, and may even stimulate their full immersion in story scenarios. However, different from traditional film-making, where the audience is completely passive in following along director’s decisions of storytelling, more freedom in VR might cause viewers to get lost on halfway watching a series of events that build up a story. Therefore, striking a balance between user interaction and narrative progression is a big challenge for filmmakers. To assist in organizing the research space, we presented a media review and the resulting framework to characterize the primary differences among different variations of film, media, games, and VR storytelling. The evaluation in particular provided us with knowledge that were closely associated with story-progression strategies and gaze redirection methods for interactive content in the commercial domain. Following the existing VR storytelling framework, we then approached the problem of guiding the audience through the major events of a story by introducing a virtual character as a travel companion who provides assistance in directing the viewer’s focus to the target scenes. The presented research explored a new technique that allowed a separate virtual character to be overlaid on top of an existing 360-degree video such that the added character react based on the head-tracking data to help indicate to the viewer the core focal content of the story. The motivation behind this research is to assist directors in using a virtual guiding character to increase the effectiveness of VR storytelling, assuring that viewers fully understand the story through completing a sequence of events, and possibly realize a rich literary experience. To assess the effectiveness of this technique, we performed a controlled experiment by applying the method in three immersive narrative experiences, each with a control condition that was free ii from guidance. The experiment compared three variations of the character guide: 1) no guide; 2) a guide with an art style similar to the style of the video design; and 3) a character guide with a dissimilar style. All participants viewed the narrative experiences to test whether a similar art style led to better gaze behaviors that had higher likelihood of falling on the intended focus regions of the 360-degree range of the Virtual Environment (VE). By the end of the experiment, we concluded that adding a virtual character that was independent from the narrative had limited effects on users’ gaze performances when watching an interactive story in VR. Furthermore, the implemented character’s art style made very few difference to users’ gaze performance as well as their level of viewing satisfaction. The primary reason could be due to limitation of the implementation design. Besides this, the guiding body language designed for an animal character caused certain confusion for numerous participants viewing the stories. In the end, the character guide approaches still provided insights for future directors and designers into how to draw the viewers’ attention to a target point within a narrative VE, including what can work well and what should be avoide

Multi-Goal Multi-Agent Pickup and Delivery

In this work, we consider the Multi-Agent Pickup-and-Delivery (MAPD) problem, where agents constantly engage with new tasks and need to plan collision-free paths to execute them. To execute a task, an agent needs to visit a pair of goal locations, consisting of a pickup location and a delivery location. We propose two variants of an algorithm that assigns a sequence of tasks to each agent using the anytime algorithm Large Neighborhood Search (LNS) and plans paths using the Multi-Agent Path Finding (MAPF) algorithm Priority-Based Search (PBS). LNS-PBS is complete for well-formed MAPD instances, a realistic subclass of MAPD instances, and empirically more effective than the existing complete MAPD algorithm CENTRAL. LNS-wPBS provides no completeness guarantee but is empirically more efficient and stable than LNS-PBS. It scales to thousands of agents and thousands of tasks in a large warehouse and is empirically more effective than the existing scalable MAPD algorithm HBH+MLA*. LNS-PBS and LNS-wPBS also apply to a more general variant of MAPD, namely the Multi-Goal MAPD (MG-MAPD) problem, where tasks can have different numbers of goal locations.Comment: IROS 202

Robust Position Control of PMSM Using Fractional-Order Sliding Mode Controller

A new robust fractional-order sliding mode controller (FOSMC) is proposed for the position control of a permanent magnet synchronous motor (PMSM). The sliding mode controller (SMC), which is insensitive to uncertainties and load disturbances, is studied widely in the application of PMSM drive. In the existing SMC method, the sliding surface is usually designed based on the integer-order integration or differentiation of the state variables, while in this proposed robust FOSMC algorithm, the sliding surface is designed based on the fractional-order calculus of the state variables. In fact, the conventional SMC method can be seen as a special case of the proposed FOSMC method. The performance and robustness of the proposed method are analyzed and tested for nonlinear load torque disturbances, and simulation results show that the proposed algorithm is more robust and effective than the conventional SMC method

Catalytic Ozonation of Recalcitrant Organic Chemicals in Water Using Vanadium Oxides Loaded ZSM-5 Zeolites

The discharge of wastewater having recalcitrant chemical compositions can have significant and adverse environmental effects. The present study investigates the application of a catalytic ozonation treatment for the removal of recalcitrant organic chemicals (ROCs) from the water. Novel catalytic materials using vanadium (V) oxides deposited onto the surface of NaZSM-5 zeolites (V/ZSM) were found to be highly efficient for this purpose. The highly-dispersed V oxides (V4+ and V5+) and Si-OH-Al framework structures were determined to promote the surface reaction and generation of hydroxyl radicals. The constructed V1/ZSM450 (0.7 wt% of V loading and 450°C of calcination) exhibited the highest activity among the developed catalyst compositions. The V1/ZSM450-COP increased the mineralization rate of nitrobenzene and benzoic acid by 50 and 41% in comparison to single ozonation. This study demonstrates the enhanced potential of V/ZSM catalysts used with catalytic ozonation process (COP) for the treatment of chemical wastewaters

NiO-polyoxometalate nanocomposites as efficient catalysts for the oxidative dehydrogenation of propane and isobutane

Novel nanocomposites of NiO and polyoxometalate (Cs2.5H0.5PMo12O40) with particle sizes in the range of 5-10 nm showed exceptional oxygen and ammonia adsorption capabilities, and the nanocomposites catalyzed the oxidative dehydrogenation of propane and isobutane efficiently under mild conditions.NSFC [20625310, 20773099, 20873110]; National Basic Research Program of China [2005CB221408]; Program for New Century Excellent Talents in Fujian Provinc

Identification of avian polyomavirus and its pathogenicity to SPF chickens

The research aimed to study an Avian polyomavirus strain that was isolated in Shandong, China. To study the pathogenicity of APV in SPF chickens, and provide references for epidemiological research and disease prevention and control of APV. The genetic characterization of APV strain (termed APV-20) was analyzed and the pathogenicity of APV was investigated from two aspects: different age SPF chickens, and different infection doses. The results revealed that the APV-20 exhibits a nucleotide homology of 99% with the other three APV strains, and the evolution of APV In China was slow. In addition, the APV-20 infection in chickens caused depression, drowsiness, clustering, and fluffy feathers, but no deaths occurred in the infected chickens. The main manifestations of necropsy, and Hematoxylin and Eosin staining (HE) showed that one-day-old SPF chickens were the most susceptible, and there was a positive correlation between viral load and infection dose in the same tissue. This study showed that SPF chickens were susceptible to APV, and an experimental animal model was established. This study can provide a reference for the pathogenic mechanism of immune prevention and control of APV

Genome-wide dose-dependent inhibition of histone deacetylases studies reveal their roles in enhancer remodeling and suppression of oncogenic super-enhancers.

Histone deacetylase inhibitors (HDACIs) are known to alter gene expression by both up- and down-regulation of protein-coding genes in normal and cancer cells. However, the exact regulatory mechanisms of action remain uncharacterized. Here we investigated genome wide dose-dependent epigenetic and transcriptome changes in response to HDACI largazole in a transformed and a non-transformed cell line. Exposure to low nanomolar largazole concentrations

Self-structuring of lamellar bridged silsesquioxanes with long side spacers

Diurea cross-linked bridged silsesquioxanes (BSs) C(10)C(11)C(10) derived from organosilane precursors, including decylene chains as side spacers and alkylene chains with variable length as central spacers (EtO)(3)Si- (CH(2))(10)-Y(CH(2))(n)-Y-(CH(2))(10)-Si(OEt)(3) (n = 7, 9-12; Y = urea group and Et = ethyl), have been synthesized through the combination of self-directed assembly and an acid-catalyzed sol gel route involving the addition of dimethylsulfoxide (DMSO) and a large excess of water. This new family of hybrids has enabled us to conclude that the length of the side spacers plays a unique role in the structuring of alkylene-based BSs, although their morphology remains unaffected. All the samples adopt a lamellar structure. While the alkylene chains are totally disordered in the case of the C(10)C(7)C(10) sample, a variable proportion of all-trans and gauche conformers exists in the materials with longer central spacers. The highest degree of structuring occurs for n = 9. The inclusion of decylene instead of propylene chains as side spacers leads to the formation of a stronger hydrogen-bonded urea-urea array as evidenced by two dimensional correlation Fourier transform infrared spectroscopic analysis. The emission spectra and emission quantum yields of the C(10)C(n)C(10) Cm materials are similar to those reported for diurea cross-linked alkylene-based BSs incorporating propylene chains as side spacers and prepared under different experimental conditions. The emission of the C(10)C(n)C(10) hybrids is ascribed to the overlap of two distinct components that occur within the urea cross-linkages and within the siliceous nanodomains. Time-resolved photoluminescence spectroscopy has provided evidence that the average distance between the siliceous domains and the urea cross-links is similar in the C(10)C(n)C(10) BSs and in oxyethylene-based hybrid analogues incorporating propylene chains as side spacers (diureasils), an indication that the longer side chains in the former materials adopt gauche conformations. It has also allowed us to demonstrate for the first time that the emission features of the urea-related component of the emission of alkylene-based BSs depend critically on the length of the side spacers