Deformation embedding for point-based elastoplastic simulation

pre-printWe present a straightforward, easy-to-implement, point-based approach for animating elastoplastic materials. The core idea of our approach is the introduction of embedded space-the least-squares best fit of the material's rest state into three dimensions. Nearest neighbor queries in the embedded space efficiently update particle neighborhoods to account for plastic flow. These queries are simpler and more efficient than remeshing strategies employed in mesh-based finite element methods.We also introduce a new estimate for the volume of a particle, allowing particle masses to vary spatially and temporally with fixed density. Our approach can handle simultaneous extreme elastic and plastic deformations. We demonstrate our approach on a variety of examples that exhibit a wide range of material behaviors

Strain limiting for clustered shape matching

journal articleIn this paper, we advocate explicit symplectic Euler integration and strain limiting in a shape matching simulation framework. The resulting approach resembles not only previous work on shape matching and strain limiting, but also the recently popular position-based dynamics. However, unlike this previous work, our approach reduces to explicit integration under small strains, but remains stable in the presence of non-linearities

Finding Better Ways: Exploring techniques to support Native American and Low-income Students in a Middle School

This paper explored four techniques middle school educators used to increase the academic success and engagement of Native American and low-income students in the classrooms. Two researchers studied the effects of relationship building and culturally relevant writing curriculum on student engagement. The other two researchers studied the effects of vocabulary instruction and differentiated assessments on student academic success. Twenty four Native American or low income students in grades 6 through 8 were studied. Data was collected through student surveys, observations, and assessment results to determine the effectiveness of these four strategies. The researchers found that the relationship building and culturally relevant writing curriculum were effective tools in increasing student engagement. Academic vocabulary strategies documented an increase in student academic success. Differentiated assessments did not have an impact on student academic success. Teachers can benefit from the success of these strategies in addition to their current methods of teaching to help their Native American and low income students stay on task in class and succeed academically

Sensor Based Auditory And Haptic Guidance System

A system and method are disclosed that use data provided by a mobile device equipped with sensors to guide a human or machine along a vector path through sensory feedback. The system uses motion and depth sensor information and object recognition to create models of an interior space, which facilitate movement for a person who has never been inside a space before, and to use those models for navigation. The method utilizes interior space maps to identify safe vectors. A realtime algorithm compares the user’s location and direction of movement with the desired path in the model, providing a measure of the deviation. It then plays an auditory and/or haptic signal that focuses the user’s attention to follow a safe path in response to the deviation. Using realtime object recognition sensor data allows the detection of spatial obstacles that are otherwise difficult to navigate using traditional solutions for aiding the visually impaired

The impact of location and type on the performance of low-voltage network connected battery energy storage systems

This paper assesses the impact of the location and configuration of Battery Energy Storage Systems (BESS) on Low-Voltage (LV) feeders. BESS are now being deployed on LV networks by Distribution Network Operators (DNOs) as an alternative to conventional reinforcement (e.g. upgrading cables and transformers) in response to increased electricity demand from new technologies such as electric vehicles. By storing energy during periods of low demand and then releasing that energy at times of high demand, the peak demand of a given LV substation on the grid can be reduced therefore mitigating or at least delaying the need for replacement and upgrade. However, existing research into this application of BESS tends to evaluate the aggregated impact of such systems at the substation level and does not systematically consider the impact of the location and configuration of BESS on the voltage profiles, losses and utilisation within a given feeder. In this paper, four configurations of BESS are considered: single-phase, unlinked three-phase, linked three-phase without storage for phase-balancing only, and linked three-phase with storage. These four configurations are then assessed based on models of two real LV networks. In each case, the impact of the BESS is systematically evaluated at every node in the LV network using Matlab linked with OpenDSS. The location and configuration of a BESS is shown to be critical when seeking the best overall network impact or when considering specific impacts on voltage, losses, or utilisation separately. Furthermore, the paper also demonstrates that phase-balancing without energy storage can provide much of the gains on unbalanced networks compared to systems with energy storage

Comparative use of active searches and artificial refuges to detect amphibians in terrestrial environments

Artificial refuges (cover boards) are commonly used to survey and monitor herpetofauna in many parts of the world. Despite the extensive use of artificial refuges in mesic environments, their effectiveness for detecting amphibians in temperate zones has rarely been examined. We compared amphibian detection probabilities between two survey methods; active searches of natural habitat and artificial refuges of three different types (corrugated steel, roofing tiles and timber railway sleepers). Our study area included five bioregions encompassing a 1,180 km latitudinal gradient across a modified, temperate eucalypt woodland vegetation community in south-eastern Australia. We deployed 14,778 artificial refuges in terrestrial environments, within patches of remnant vegetation, and collected presence and abundance data on herpetofauna between 1999 and 2017. We used Bayesian logistic regression to identify the most effective survey method for detecting frog species across all bioregions. We modelled frog detections by fitting survey method, time since refuge deployment, and rainfall prior to each survey. We detected 3970 individuals from 18 frog species. Overall, we found active searches and timber substrates most effective for detecting a broad range of species, although detection rates were driven by the numerically abundant spotted marsh frog Limnodynastes tasmaniensis. Timber refuges were effective for detecting several burrowing species, whereas active searches were effective at detecting habitat generalists. Quadratic effects of rainfall prior to survey as opposed to linear effects of time since artificial refuge placement was important in explaining frog detection rates in some bioregions. Active searches, timber railway sleepers and sheets of corrugated steel provide complimentary survey methods for detecting amphibians, although detection rates are influenced by rainfall patterns. Artificial refuges provide a time-effective and standardised method for studying amphibians in their non-breeding terrestrial environment and should be incorporated into future surveys and biodiversity monitoring programs.The work was funded by the Australian Govern-ment's Caring for Our Country Initiative, the National Environmental Science Program's Threatened Species Recovery Hub and the Australian Research Council, and is supported by the Murray Local Land Services, Riverina Local land Services, Central Tablelands Local land Services, North East Catchment Management Authority, Goulburn Broken Catchment Management Authority, NSW Environment Trust, Ian Potter Foundation and the Vincent Fairfax Family Foundation

UAS Literary & Arts Journal

Proof copy provided by Tidal Echoes.The 2015 edition of Tidal Echoes presents an annual showcase of writers and artists who share one thing in common: a life surrounded by the rainforests and waterways of Southeast Alaska.Dedication -- Editor’s Note -- Mid-Air -- Acknowledgements -- Salmon (Gohan Desu Yo/It’s Dinner Time) -- Xwaayeenák Richard Dauenhauer -- Loon -- Burney Falls -- Richard Dauenhauer -- Egg Carton Fox -- August Afternoon at Helle’s Pool, Vancouver, Washington -- Oak Run -- Buddy Tabor teaches me to filet a halibut -- Icelander -- Home -- Season’s End -- Young Me, Old Me -- The Window Seat -- Wind -- UAS Student Back Study -- Paintbrush Conversations -- Grey River Soulshine -- Across the Universe -- Aurora-Skaters’ Cabin 1 -- Whiskey and Autumn -- Leaf Wolf -- Spring Cleaning the Perennials -- Ode to a Rose -- Final Point -- After Spring Recital -- Olympic Ceiling -- Rodda-Hard going (too little snow) -- Birch Bark Calligraphy No. 2 -- Fishtailing -- Working the Corks -- Modern Alaskan Storyteller: An Interview with Ishmael Hope -- Bailer at the Back of the Boat (Excerpt) -- Close Up -- Bothering the Dauenhauers -- In Memory of Andrew Hope III -- Wolf Brimhat -- I Am From -- Crossing -- Revelations and Realizations -- The Shrinking Girl -- Untitled (Andi in Niki’s Room) -- Afternoon Reading, Rainy Room -- My Grandmother’s House in Metlakatla -- Deacon Charles Rohrbacher, Icon of St. Nicholas -- Honoring Tibet -- Fumi Matsumoto: Finding Art in Culture -- Pathway of Thorns -- Minidoka Interlude -- Mountain Dew Parrots -- Watch Out for Falling Objects -- Loose Change -- An Unkind Demise -- A Place That Holds Names -- Immortality (skull side) -- Opening Again the Box of Wisdom -- Iff’n I Go -- Colorless Blues -- The Heartsdance -- King of Dreams -- Hungering -- Colonialism -- Inside Out -- Rachel Day -- Lying Here -- Note to Wife -- Death -- Round the Clock -- Untitled (trap) -- Seeds of Racism -- Auschwitz Remembrance -- Moab 1 -- Pearl of the Orient -- Moab 3 -- Scars -- Transporting -- In Eliason Harbor -- Poet Passes: Leaves Words Behind -- Tough Guy -- Wolf Helmet -- Biographie

Spatiotemporal effects of logging and fire on tall, wet temperate eucalypt forest birds

Forests globally are subject to disturbances such as logging and fire that create complex temporal variation in spatial patterns of forest cover and stand age. However, investigations that quantify temporal changes in biodiversity in response to multiple forms of disturbance in space and time are relatively uncommon. Over a 10-yr period, we investigated the response of bird species to spatiotemporal changes in forest cover associated with logging and wildfire in the mountain ash (Eucalyptus regnans) forests of southeastern Australia. Specifically, we examined how bird occurrence changed with shifts in the proportion of area burned or logged in a 4.5 km radius surrounding our 88 long-term field survey sites, each measuring 1 ha in size. Overall species richness was greatest in older forest patches, but declined as the amount of fire around each site increased. At the individual species level, 31 of the 37 bird species we modeled exhibited a negative response to the amount of fire in the surrounding landscape, while one species responded positively to fire. Only nine species exhibited signs of recovery in the 6 yr of surveys following the fire. Five species were more likely to be detected as the proportion of logged forest surrounding a site increased, suggesting a possible "concentration effect" with displaced birds moving into unlogged areas following harvesting of adjacent areas. We also identified relationships between the coefficients of life history attributes and spatiotemporal changes in forest cover and stand age. Large-bodied birds and migratory species were associated with landscapes subject to large amounts of fire in 2009. There were associations between old growth stands and small-bodied bird species and species that were not insectivores. Our study shows that birds in mountain ash forests are strongly associated with old growth stands and exhibit complex, time-dependent, and species-specific responses to landscape disturbance. Despite logging and fire both being high-severity perturbations, no bird species exhibited similar responses to fire and logging in the landscape surrounding our sites. Thus, species responses to one kind of landscape-scale disturbance are not readily predictable based on an understanding of the responses to another kind of (albeit superficially similar) disturbance.Threatened Species Recovery Hub of the National Environmental Science Program, Parks Victoria, and Victorian Government Department of Environment, Land, Water and Plannin