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Capture Data (capture + data)
Kinds of Capture Data Selected AbstractsCompression of Human Motion Capture Data Using Motion Pattern IndexingCOMPUTER GRAPHICS FORUM, Issue 1 2009Qin Gu I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism; E.4 [Coding and Information Theory]: Data Compaction and Compression Abstract In this work, a novel scheme is proposed to compress human motion capture data based on hierarchical structure construction and motion pattern indexing. For a given sequence of 3D motion capture data of human body, the 3D markers are first organized into a hierarchy where each node corresponds to a meaningful part of the human body. Then, the motion sequence corresponding to each body part is coded separately. Based on the observation that there is a high degree of spatial and temporal correlation among the 3D marker positions, we strive to identify motion patterns that form a database for each meaningful body part. Thereafter, a sequence of motion capture data can be efficiently represented as a series of motion pattern indices. As a result, higher compression ratio has been achieved when compared with the prior art, especially for long sequences of motion capture data with repetitive motion styles. Another distinction of this work is that it provides means for flexible and intuitive global and local distortion controls. [source] Species Composition of Neotropical Understory Bird Communities: Local Versus Regional Perspectives Based on Capture DataBIOTROPICA, Issue 1 2009John G. Blake ABSTRACT Species richness and composition of bird assemblages found in the understory of undisturbed Neotropical forests vary at local and regional scales but the extent of that variation has not been well documented. Yet, such variation can be important for understanding patterns of diversity and for conservation. Here, we use capture data from two ca 100-ha study plots (sampled from March 2001 through March 2005) to compare understory assemblages at a local scale; nets on the plots were separated by approximately 1.7 km at the closest point. A total of 157 species (133 per plot) was represented in 6023 captures of 4001 individuals. After eliminating species not likely to be well-sampled with nets, there were 122 species total with 110 and 113 on the two plots, respectively. Species-accumulation curves and abundance-rank relationships were almost identical on both plots. Capture rates were high (53 and 56 birds captured per 100 mist-net-hours, mnh) on both plots. Distributions of species and individuals among families and genera were similar on the two plots but numbers of captures of some common species differed between plots in response to small-scale variation in environmental features. Indicator-species analyses selected seven species as more characteristic of one plot and nine as more characteristic of the other. At the regional level, understory assemblages were most similar to a site in Peru but differed from sites in Brazil, Venezuela, and, especially, Costa Rica. Dissimilarity in species richness per family was related to geographic distance only when Costa Rica was included in the analysis. RESUMEN La riqueza de especies y la composición de ensambles de aves de sotobosque en bosques neotropicales varían a escala local y regional, pero el grado de variación no ha sido bien documentado. Sin embargo, esta variación puede ser importante para entender los patrones de diversidad y para conservación. En este trabajo usamos datos de captura de dos parcelas de ca 100-ha (muestreados entre Marzo 2001 y Marzo 2005) para comparar los ensambles de aves de sotobosque a escala local; las redes en las dos parcelas estuvieron ubicadas a una distancia mínima aproximada de 1.7 km. Un total de 157 especies (133 por parcela) estuvieron representadas por 6023 capturas correspondientes a 4001 individuos. Una vez eliminadas aquellas especies que no son factibles de ser muestreadas adecuadamente con redes, el total de especies fue de 122, con 110 y 113 en cada una de los parcelas, respectivamente. Las curvas de acumulación de especies y las relaciones abundancia-rango fueron casi idénticas en ambas parcelas. Las tasas de captura fueron altas (53 y 56 aves capturadas por 100 horas red). La distribución de especies e individuos entre familias y géneros fueron similares en las dos parcelas, pero los números de captura de algunas especies comunes difirieron entre las parcelas en respuesta a la variación de características ambientales a pequeña escala. Los análisis de especies indicadoras seleccionaron siete especies como las más características de una de las parcelas y nueve como las más características de la otra. A nivel regional los ensambles de aves de sotobosque fueron más similares a aquellos presentes en un sitio en Perú, pero fueron diferentes a los presentes en sitios de Brasil, Venezuela y especialmente Costa Rica. La diferencia en riqueza de especies por familia estuvo relacionada con la distancia geográfica sólo cuando Costa Rica fue incluida en el análisis. [source] A hybrid approach for simulating human motion in constrained environmentsCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3-4 2010Jia Pan Abstract We present a new algorithm to generate plausible motions for high-DOF human-like articulated figures in constrained environments with multiple obstacles. Our approach is general and makes no assumptions about the articulated model or the environment. The algorithm combines hierarchical model decomposition with sample-based planning to efficiently compute a collision-free path in tight spaces. Furthermore, we use path perturbation and replanning techniques to satisfy the kinematic and dynamic constraints on the motion. In order to generate realistic human-like motion, we present a new motion blending algorithm that refines the path computed by the planner with motion capture data to compute a smooth and plausible trajectory. We demonstrate the results of generating motion corresponding to placing or lifting object, walking, and bending for a 38-DOF articulated model. Copyright © 2010 John Wiley & Sons, Ltd. [source] Interactive animation of virtual humans based on motion capture dataCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 5-6 2009Franck Multon Abstract This paper presents a novel, parameteric framework for synthesizing new character motions from existing motion capture data. Our framework can conduct morphological adaptation as well as kinematic and physically-based corrections. All these solvers are organized in layers in order to be easily combined together. Given locomotion as an example, the system automatically adapts the motion data to the size of the synthetic figure and to its environment; the character will correctly step over complex ground shapes and counteract with external forces applied to the body. Our framework is based on a frame-based solver. This ensures animating hundreds of humanoids with different morphologies in real-time. It is particularly suitable for interactive applications such as video games and virtual reality where a user interacts in an unpredictable way. Copyright © 2009 John Wiley & Sons, Ltd. [source] Accurate automatic visible speech synthesis of arbitrary 3D models based on concatenation of diviseme motion capture dataCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 5 2004Jiyong Ma Abstract We present a technique for accurate automatic visible speech synthesis from textual input. When provided with a speech waveform and the text of a spoken sentence, the system produces accurate visible speech synchronized with the audio signal. To develop the system, we collected motion capture data from a speaker's face during production of a set of words containing all diviseme sequences in English. The motion capture points from the speaker's face are retargeted to the vertices of the polygons of a 3D face model. When synthesizing a new utterance, the system locates the required sequence of divisemes, shrinks or expands each diviseme based on the desired phoneme segment durations in the target utterance, then moves the polygons in the regions of the lips and lower face to correspond to the spatial coordinates of the motion capture data. The motion mapping is realized by a key-shape mapping function learned by a set of viseme examples in the source and target faces. A well-posed numerical algorithm estimates the shape blending coefficients. Time warping and motion vector blending at the juncture of two divisemes and the algorithm to search the optimal concatenated visible speech are also developed to provide the final concatenative motion sequence. Copyright © 2004 John Wiley & Sons, Ltd. [source] Compression of Human Motion Capture Data Using Motion Pattern IndexingCOMPUTER GRAPHICS FORUM, Issue 1 2009Qin Gu I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism; E.4 [Coding and Information Theory]: Data Compaction and Compression Abstract In this work, a novel scheme is proposed to compress human motion capture data based on hierarchical structure construction and motion pattern indexing. For a given sequence of 3D motion capture data of human body, the 3D markers are first organized into a hierarchy where each node corresponds to a meaningful part of the human body. Then, the motion sequence corresponding to each body part is coded separately. Based on the observation that there is a high degree of spatial and temporal correlation among the 3D marker positions, we strive to identify motion patterns that form a database for each meaningful body part. Thereafter, a sequence of motion capture data can be efficiently represented as a series of motion pattern indices. As a result, higher compression ratio has been achieved when compared with the prior art, especially for long sequences of motion capture data with repetitive motion styles. Another distinction of this work is that it provides means for flexible and intuitive global and local distortion controls. [source] Pedestrian Reactive Navigation for Crowd Simulation: a Predictive ApproachCOMPUTER GRAPHICS FORUM, Issue 3 2007Sébastien Paris This paper addresses the problem of virtual pedestrian autonomous navigation for crowd simulation. It describes a method for solving interactions between pedestrians and avoiding inter-collisions. Our approach is agent-based and predictive: each agent perceives surrounding agents and extrapolates their trajectory in order to react to potential collisions. We aim at obtaining realistic results, thus the proposed model is calibrated from experimental motion capture data. Our method is shown to be valid and solves major drawbacks compared to previous approaches such as oscillations due to a lack of anticipation. We first describe the mathematical representation used in our model, we then detail its implementation, and finally, its calibration and validation from real data. [source] Visyllable Based Speech AnimationCOMPUTER GRAPHICS FORUM, Issue 3 2003Sumedha Kshirsagar Visemes are visual counterpart of phonemes. Traditionally, the speech animation of 3D synthetic faces involvesextraction of visemes from input speech followed by the application of co-articulation rules to generate realisticanimation. In this paper, we take a novel approach for speech animation , using visyllables, the visual counterpartof syllables. The approach results into a concatenative visyllable based speech animation system. The key contributionof this paper lies in two main areas. Firstly, we define a set of visyllable units for spoken English along withthe associated phonological rules for valid syllables. Based on these rules, we have implemented a syllabificationalgorithm that allows segmentation of a given phoneme stream into syllables and subsequently visyllables. Secondly,we have recorded the database of visyllables using a facial motion capture system. The recorded visyllableunits are post-processed semi-automatically to ensure continuity at the vowel boundaries of the visyllables. We defineeach visyllable in terms of the Facial Movement Parameters (FMP). The FMPs are obtained as a result of thestatistical analysis of the facial motion capture data. The FMPs allow a compact representation of the visyllables.Further, the FMPs also facilitate the formulation of rules for boundary matching and smoothing after concatenatingthe visyllables units. Ours is the first visyllable based speech animation system. The proposed technique iseasy to implement, effective for real-time as well as non real-time applications and results into realistic speechanimation. Categories and Subject Descriptors (according to ACM CCS): 1.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism [source] A general model for predicting brown tree snake capture ratesENVIRONMETRICS, Issue 3 2003Richard M. Engeman Abstract The inadvertent introduction of the brown tree snake (Boiga irregularis) to Guam has resulted in the extirpation of most of the island's native terrestrial vertebrates, has presented a health hazard to small children, and also has produced economic problems. Trapping around ports and other cargo staging areas is central to a program designed to deter dispersal of the species. Sequential trapping of smaller plots is also being used to clear larger areas of snakes in preparation for endangered species reintroductions. Traps and trapping personnel are limited resources, which places a premium on the ability to plan the deployment of trapping efforts. In a series of previous trapping studies, data on brown tree snake removal from forested plots was found to be well modeled by exponential decay functions. For the present article, we considered a variety of model forms and estimation procedures, and used capture data from individual plots as random subjects to produce a general random coefficients model for making predictions of brown tree snake capture rates. The best model was an exponential decay with positive asymptote produced using nonlinear mixed model estimation where variability among plots was introduced through the scale and asymptote parameters. Practical predictive abilities were used in model evaluation so that a manager could project capture rates in a plot after a period of time, or project the amount of time required for trapping to reduce capture rates to a desired level. The model should provide managers with a tool for optimizing the allocation of limited trapping resources. Copyright © 2003 John Wiley & Sons, Ltd. [source] Contradictory results from different methods for measuring direction of insect flightFRESHWATER BIOLOGY, Issue 10 2004Kate H. Macneale Summary 1. Stream ecologists have been puzzled by the apparent paradox that invertebrate populations persist in headwater streams despite the high frequency with which individuals drift downstream. To resolve this ,drift paradox', directions and distances of both larval and adult movement must be identified. Using over 50 interception traps in combination with results from several mark,capture experiments using 15N as a label, we tested the assumption that interception traps accurately represent the ultimate direction of adult insect flight. 2. In several streams in the Hubbard Brook Experimental Forest, 76% of 15N-labelled stoneflies (Leuctra ferruginea) had flown upstream from where they emerged to where they were captured. In contrast, over 60% of stoneflies were flying downstream when captured, i.e. on the upstream side of an interception trap. 3. The instantaneous direction, as indicated by the side of the interception trap on which they were captured, indicated the ultimate flight direction for fewer than 1/3 of the individuals captured. Thus, such traps did not accurately reflect the ultimate flight patterns of individuals, as indicated by mark,capture data. 4. Conclusions drawn from interception trap counts regarding the direction of movement and the distribution and persistence of populations may need to be re-evaluated. We suggest that better tracking methods, including mass mark,capture studies using stable isotopes, be used to evaluate the potentially complex patterns of adult insect movement and the consequences of that movement for individuals and populations. [source] Ecological correlates of vulnerability to fragmentation in Neotropical batsJOURNAL OF APPLIED ECOLOGY, Issue 1 2008Christoph F. J. Meyer Summary 1In the face of widespread human-induced habitat fragmentation, identification of those ecological characteristics that render some species more vulnerable to fragmentation than others is vital for understanding, predicting and mitigating the effects of habitat alteration on biodiversity. We compare hypotheses on the causes of interspecific differences in fragmentation sensitivity using distribution and abundance data collected on 23 species of Neotropical bats. 2Bats were captured over a 2-year period on 11 land-bridge islands in Gatún Lake, Panama, and on the adjacent mainland. We derived a series of explanatory variables from our capture data and from the literature: (1) natural abundance in continuous forest, (2) body mass, (3) trophic level, (4) dietary specialization, (5) vertical stratification, (6) edge-sensitivity, (7) mobility, (8) wing morphology (aspect ratio and relative wing loading) and (9) ecologically scaled landscape indices (ESLIs). After phylogenetic correction, these variables were used separately and in combination to assess their association with two indices of fragmentation sensitivity, species prevalence (proportion of islands occupied) as well as an index of change in abundance. 3Model selection based on Akaike's information criterion identified edge-sensitivity as the best correlate of vulnerability to fragmentation. Natural abundance and mobility or traits linked to mobility (relative wing loading and ESLI) received limited support as predictors. Vulnerability of gleaning animalivorous bats is probably caused by a combination of these traits. 4Synthesis and applications. Our findings emphasize the importance of a local-scale approach in developing predictive models of species fragmentation sensitivity and indicate that risk assessments of Neotropical bats could be based on species tolerance to habitat edges and mobility-related traits. We suggest that, in order to be effective, management efforts should aim to minimize the amount of edge-habitat and reduce the degree of fragment-matrix contrast. Moreover, if high bat diversity is to be preserved in fragmented Neotropical landscapes, conservation measures regarding reserve design should assure spatial proximity to source populations in larger tracts of continuous forest and a low degree of remnant isolation. [source] Sampling plan for the coffee leaf miner Leucoptera coffeella with sex pheromone trapsJOURNAL OF APPLIED ENTOMOLOGY, Issue 6 2008T. Bacca Abstract The population density of the coffee leaf miner Leucoptera coffeella (Guérin-Méneville & Perrottet) (Lep., Lyonetiidae) can be estimated using pheromone traps in coffee fields as male capture reflects this pest damage based on previous correlational study. However, the spatial distribution of pheromone traps and their density are necessary to optimize the sampling procedure with pheromone traps. Therefore, the objectives of the present study were to determine the pheromone trap density required per hectare to sample coffee leaf miner populations and to determine the spatial distribution of the males of this pest species. The males were sampled every 8 days in 12 consecutive evaluations. Taylor's power law and frequency distributions were used to recognize the distribution of the male capture data, which followed a negative binomial distribution. A common K was obtained, allowing the establishment of a single conventional sampling plan for the 12 fields investigated. The adjusted sampling plan requires eight traps in an area of 30 ha for a 25% precision error. Kriging-generated maps allowed the simulation of male captures for 8, 12 and 20 traps per 30 ha and the results were compared with those obtained with absolute sampling resulting in R2 -values of 0.30, 0.57 and 0.60 respectively. The traps were able to identify the more highly infested areas within the field and are a precise and efficient tool for sampling populations of L. coffeella. [source] Conservation and management implications of fine-scale genetic structure of Gulf sturgeon in the Pascagoula River, MississippiJOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2004M. A. Dugo Summary The anadromous Gulf sturgeon occurs along the north central coast of the Gulf of Mexico and is federally listed as threatened. We analyzed fine-scale patterns of Gulf sturgeon population structure, focusing on the Pascagoula River drainage of Mississippi, in reference to movement patterns as determined via telemetry and capture data. We genotyped 361 Gulf sturgeon using eight microsatellite loci including samples from the Pascagoula, Pearl, Escambia, Yellow, Choctawhatchee, and Apalachicola river drainages. Pairwise FST estimates indicated that genetic structure occurs at least at the drainage level. The Pascagoula and Pearl rivers form a western group, demonstrating 100% bootstrap support for a division with drainages to the east. Assignment tests detected non-natal genotypes occurring in all drainages. According to assignment tests, the Pascagoula supports an admixture of individuals, containing minimal influence from drainages to the east (2%) and substantial interaction with the Pearl River (14.1%). The occurrence of Pascagoula River fish in the Pearl was non-reciprocal, observed at 1.1%. After accounting for non-natal genetic diversity within the Pascagoula, there remained a disparity between a pooled Pascagoula group and the only documented spawning site within the drainage located in the Bouie River. We interpret this as an indication of a second genetic stock within the Pascagoula River drainage. Radio telemetry data suggest that spawning likely occurs in the Chickasawhay River, in areas isolated from the Bouie River spawning site by about 350 river kilometers. We emphasize the utility of integrating field and molecular approaches when delineating fine-scale patterns of population structure in anadromous fishes. [source] Kinship and social structure of bobcats (Lynx rufus) inferred from microsatellite and radio-telemetry dataJOURNAL OF ZOOLOGY, Issue 4 2006J. E. Jane Abstract Kinship analysis using 12 microsatellites was compared with radio-telemetry data to examine the social structure of bobcats Lynx rufus in southern Texas. Genetically identified kinship relationships combined with capture data were used to reconstruct pedigrees. Three family groups were constructed from parent/offspring pairs identified from shared alleles. All parents identified by genetic analysis had established home ranges. Individuals with no distinct home ranges were not genetically observed to have offspring among the bobcats sampled. This suggests that establishing a home range is necessary for bobcats to breed. Of three identified male offspring and three identified female offspring, two female offspring were philopatric. These females became a part of the breeding population in their natal area. Among sibling pairs that included nine female and four male individuals, four females and one male were residents suggesting male-biased dispersal. [source] A mark,recapture study of the caecilian amphibian Gegeneophis ramaswamii (Amphibia: Gymnophiona: Caeciliidae) in southern IndiaJOURNAL OF ZOOLOGY, Issue 2 2003G. John Measey Abstract The potentially important ecology of subterranean predators of soil ecosystem engineers is poorly understood. This is especially true of caecilian amphibians (Gymnophiona) for which there are virtually no quantitative data. Results of the first field trials of permanent marking in caecilians are presented. A preliminary assessment is made of the efficacy of mark,recapture studies for estimating population size of Gegeneophis ramaswamii Taylor in 100 m2 of low intensity agriculture in Kerala, India. Over three sampling occasions spanning 58 days of the monsoon season, 114 individuals were captured, 104 marked and released, and 21 recaptured. Models estimate an open population of 60 individuals (95% confidence interval of 45.2 to 151.3), and a closed population of 236 (95% confidence interval of 174 to 351). A census interpretation of the raw capture data gives densities of about 0.31 to 0.48 m,2. Results suggest large movement in and out of the sampled area during the study. Despite caveats associated with these data, progress is made in identifying potential limitations and improvements in the methods used. This study highlights the paucity of knowledge of caecilian ecology, and the need for long-term studies to elucidate further ecological information and to monitor populations. [source] Species Composition of Neotropical Understory Bird Communities: Local Versus Regional Perspectives Based on Capture DataBIOTROPICA, Issue 1 2009John G. Blake ABSTRACT Species richness and composition of bird assemblages found in the understory of undisturbed Neotropical forests vary at local and regional scales but the extent of that variation has not been well documented. Yet, such variation can be important for understanding patterns of diversity and for conservation. Here, we use capture data from two ca 100-ha study plots (sampled from March 2001 through March 2005) to compare understory assemblages at a local scale; nets on the plots were separated by approximately 1.7 km at the closest point. A total of 157 species (133 per plot) was represented in 6023 captures of 4001 individuals. After eliminating species not likely to be well-sampled with nets, there were 122 species total with 110 and 113 on the two plots, respectively. Species-accumulation curves and abundance-rank relationships were almost identical on both plots. Capture rates were high (53 and 56 birds captured per 100 mist-net-hours, mnh) on both plots. Distributions of species and individuals among families and genera were similar on the two plots but numbers of captures of some common species differed between plots in response to small-scale variation in environmental features. Indicator-species analyses selected seven species as more characteristic of one plot and nine as more characteristic of the other. At the regional level, understory assemblages were most similar to a site in Peru but differed from sites in Brazil, Venezuela, and, especially, Costa Rica. Dissimilarity in species richness per family was related to geographic distance only when Costa Rica was included in the analysis. RESUMEN La riqueza de especies y la composición de ensambles de aves de sotobosque en bosques neotropicales varían a escala local y regional, pero el grado de variación no ha sido bien documentado. Sin embargo, esta variación puede ser importante para entender los patrones de diversidad y para conservación. En este trabajo usamos datos de captura de dos parcelas de ca 100-ha (muestreados entre Marzo 2001 y Marzo 2005) para comparar los ensambles de aves de sotobosque a escala local; las redes en las dos parcelas estuvieron ubicadas a una distancia mínima aproximada de 1.7 km. Un total de 157 especies (133 por parcela) estuvieron representadas por 6023 capturas correspondientes a 4001 individuos. Una vez eliminadas aquellas especies que no son factibles de ser muestreadas adecuadamente con redes, el total de especies fue de 122, con 110 y 113 en cada una de los parcelas, respectivamente. Las curvas de acumulación de especies y las relaciones abundancia-rango fueron casi idénticas en ambas parcelas. Las tasas de captura fueron altas (53 y 56 aves capturadas por 100 horas red). La distribución de especies e individuos entre familias y géneros fueron similares en las dos parcelas, pero los números de captura de algunas especies comunes difirieron entre las parcelas en respuesta a la variación de características ambientales a pequeña escala. Los análisis de especies indicadoras seleccionaron siete especies como las más características de una de las parcelas y nueve como las más características de la otra. A nivel regional los ensambles de aves de sotobosque fueron más similares a aquellos presentes en un sitio en Perú, pero fueron diferentes a los presentes en sitios de Brasil, Venezuela y especialmente Costa Rica. La diferencia en riqueza de especies por familia estuvo relacionada con la distancia geográfica sólo cuando Costa Rica fue incluida en el análisis. [source] | |||||||||||||