Adult horseshoe crabs Limulus polyphemus have long served as models for the study of vision in marine arthropods. Yet, little is known about the ability of early life history stages to detect and respond to visual cue...Adult horseshoe crabs Limulus polyphemus have long served as models for the study of vision in marine arthropods. Yet, little is known about the ability of early life history stages to detect and respond to visual cues. We examined the visually directed movements of larvae and first stage juveniles to horizons containing dark visual targets of different sizes. The study tested the hypotheses that （1） larval and juvenile crabs can detect and respond to visual targets and （2） the direction of orientation varies with the presence of chemical cues associated with settlement habitats. Orientation of larval and juvenile crabs to rectangles subtending angles from 30--330~ was tested in a circular arena containing water that either lacked estuarine chemical cues （offshore water） or contained odors from aquatic vegetation or known predators. In the absence of chemical odors, larvae oriented toward and juveniles moved away from dark horizons subtending angles 〉 60~. When placed in water containing chemical odors from potential nursery habitats, including the seagrasses Halodule wrightii and Syringodium filiforme, crabs reversed their direction of orientation relative to their responses in offshore water. Odors from two known predators, the mummichug Fundulus grandis and blue crab Callinectes sapidus, had no affect on the orientation of larvae. Yet, juveniles responded to both odors by moving toward the visual target. Results support the hypothesis that the visual orientation of larval and juvenile horseshoe crabs changes upon exposure to habitat and predator cues and that the direction of the response undergoes an ontogenetic shift following metamorphosis展开更多
In nature hummingbirds face floral resources whose availability, quality and quantity can vary spatially and temporally. Thus, they must constantly make foraging decisions about which patches, plants and flowers to vi...In nature hummingbirds face floral resources whose availability, quality and quantity can vary spatially and temporally. Thus, they must constantly make foraging decisions about which patches, plants and flowers to visit, partly as a function of the nectar reward. The uncertainty of these decisions would possibly be reduced if an individual could remember locations or use visual cues to avoid revisiting recently depleted flowers. In the present study, we carried out field experiments with white-eared hummingbirds Hylocharis leucotis, to evaluate their use of locations or visual cues when foraging on natural flowers Penstemon roseus. We evaluated the use of spatial memory by observing birds while they were foraging between two plants and within a single plant. Our results showed that hummingbirds prefer to use location when foraging in two plants, but they also use visual cues to efficiently locate unvisited rewarded flowers when they feed on a single plant. However, in absence of visual cues, in both experiments birds mainly used the location of previously visited flowers to make subsequent visits. Our data suggest that hummingbirds are capable of learning and employing this flexibility depending on the faced environmental conditions and the information acquired in previous visits [Current Zoology 57 （4）： 468-476, 2011].展开更多
This paper presents a system that is able to reliably track multiple faces under varying poses(tilted and rotated)in real time.The system consists of two interactive modules.The first module performs the detection of ...This paper presents a system that is able to reliably track multiple faces under varying poses(tilted and rotated)in real time.The system consists of two interactive modules.The first module performs the detection of the face that is subject to rotation. The second module carries out online learning-based face tracking.A mechanism that switches between the two modules is embedded into the system to automatically decide the best strategy for reliable tracking.The mechanism enables a smooth transit between the detection and tracking modules when one of them gives either nil or unreliable results.Extensive experiments demonstrate that the system can reliably carry out real time tracking of multiple faces in a complex background under different conditions such as out-of-plane rotation,tilting,fast nonlinear motion,partial occlusion,large scale changes,and camera motion.Moreover,it runs at a high speed of 10～12 frames per second(fps)for an image of 320×240.展开更多
The formation of self-care ability is the first step for children with autism to enter the society,and it is also a prerequisite and guarantee for their independent survival.This study aimed to explore the impact of v...The formation of self-care ability is the first step for children with autism to enter the society,and it is also a prerequisite and guarantee for their independent survival.This study aimed to explore the impact of visual cue strategies on the self-care ability of children with autism.Based on the ABA design of a single case study,this research conducted a four-month intervention on a seven-year-old child with autism via visual cue strategy as independent variables and sock-wearing skills as dependent variables,in order to explore the effect of visual cue strategy on self-care ability of children with autism.It turned out that visual cue strategy exerts a positive immediate sustained effect and social validity on the self-care ability of children with autism.Lastly,suggestions were provided for future related research based on the research process,results,and limitations.展开更多
To improve the reliability and accuracy of visual tracker,a robust visual tracking algorithm based on multi-cues fusion under Bayesian framework is proposed.The weighed color and texture cues of the object are applied...To improve the reliability and accuracy of visual tracker,a robust visual tracking algorithm based on multi-cues fusion under Bayesian framework is proposed.The weighed color and texture cues of the object are applied to describe the moving object.An adjustable observation model is incorporated into particle filtering,which utilizes the properties of particle filter for coping with non-linear,non-Gaussian assumption and the ability to predict the position of the moving object in a cluttered environment and two complementary attributes are employed to estimate the matching similarity dynamically in term of the likelihood ratio factors;furthermore tunes the weight values according to the confidence map of the color and texture feature on-line adaptively to reconfigure the optimal observation likelihood model,which ensured attaining the maximum likelihood ratio in the tracking scenario even if in the situations where the object is occluded or illumination,pose and scale are time-variant.The experimental result shows that the algorithm can track a moving object accurately while the reliability of tracking in a challenging case is validated in the experimentation.展开更多
Mechanisms of predator detection and the influence of the presence of nonlethal predators on antipredator defense behavior and metamorphic traits were studied in the Indian tree frog, Polypedates maculatus. Exposure o...Mechanisms of predator detection and the influence of the presence of nonlethal predators on antipredator defense behavior and metamorphic traits were studied in the Indian tree frog, Polypedates maculatus. Exposure of P. maculatus tadpoles to chemical cues of caged predator（crabs, Barytelphusa spp.） fed with either conspecific or heterogeneric tadpoles, or were starved elicited defense behavior（by avoiding predator zone） in them. Such a behavior was not evident when exposed to predators housed in a glass beaker（visual cues）. Both early（Gosner stage 27–28） and later（Gosner stage 35–36） stage tadpoles when exposed to caged predators（fed with conspecific tadpoles）, prey tadpoles spent less time swimming and remained motionless for longer periods. Yet, the time spent by prey in feeding was unaffected. Further, the predator avoidance behavior exhibited by them was of the same intensity regardless of whether the caged predators were fed or starved implying the influence of predator＇s kairomones. Tadpoles reared with caged predator reached the metamorphic climax stage（MC stage; Gosner stage 42） earlier than those reared without a predator. Size at emergence（Gosner stage 46） was comparable in both the groups. The findings suggest that P. maculatus tadpoles assess predation risk chiefly by sensing kairomones of the predator in eliciting antipredator defense behaviors. Accelerated development and early metamorphosis without any compromise of the size at emergence may be due to their unaltered feeding activity.展开更多
在航空发动机可视化协同维修中,利用声音提示技术,通过改进的梅尔频率倒谱系数(Mel Frequency Cepstral Coefficients,MFCC)与头相关传递函数(Head-Related Transfer Function,HRTF)构建“频域-空间”双重映射模型,实现故障声纹特征的...在航空发动机可视化协同维修中,利用声音提示技术,通过改进的梅尔频率倒谱系数(Mel Frequency Cepstral Coefficients,MFCC)与头相关传递函数(Head-Related Transfer Function,HRTF)构建“频域-空间”双重映射模型,实现故障声纹特征的精准提取与三维声场定位。结合增强现实界面,设计多故障优先级动态调控机制,优化声学信息传递链。实验结果表明,将声音提示技术应用于航空发动机可视化协同维修,故障维修响应时间缩短至1.3 s以内,故障定位误差控制在±1.0 mm和±1.0°,同时显著减少了协同误判频次,提升了航空发动机维修的实时性与准确性。展开更多
为了解辅助沟通系统(augmentative and alternative communication,AAC)介入三部曲模式教学对提升少口语重度孤独症谱系障碍(autism spectrum disorder,ASD)成人简单社交沟通的效果,选取一名少口语重度ASD成人为个案,依其学习特质采用...为了解辅助沟通系统(augmentative and alternative communication,AAC)介入三部曲模式教学对提升少口语重度孤独症谱系障碍(autism spectrum disorder,ASD)成人简单社交沟通的效果,选取一名少口语重度ASD成人为个案,依其学习特质采用行动研究法,通过搜集教学评量结果的量化资料,以及研究者、个案的同学和朋友、个案母亲及沟通伙伴的质性观察资料,研究旨在通过教学提升个案在搭乘出租车活动时的功能性词汇、句构能力及类化至自然情境的能力。研究结果显示,AAC介入三部曲模式可增进少口语重度ASD成人的简单社交沟通表现。长期使用AAC的经验让个案对于新主题有自主性,在功能性词汇及句构学习方面能够参与教学规划。AAC介入三部曲模式对个案应有持续且长期的介入,除沟通成效外,亦对提升自主性及活动参与独立程度有所助益。展开更多
基金supported by a grant from the National Park Service (PS180060016)supported by a Graduate Teaching Fellowship (GK-12) from the National Science Foundation (Florida Tech INSTEP Program) under grant Nos.DGE 0440529 and 0638702
文摘Adult horseshoe crabs Limulus polyphemus have long served as models for the study of vision in marine arthropods. Yet, little is known about the ability of early life history stages to detect and respond to visual cues. We examined the visually directed movements of larvae and first stage juveniles to horizons containing dark visual targets of different sizes. The study tested the hypotheses that （1） larval and juvenile crabs can detect and respond to visual targets and （2） the direction of orientation varies with the presence of chemical cues associated with settlement habitats. Orientation of larval and juvenile crabs to rectangles subtending angles from 30--330~ was tested in a circular arena containing water that either lacked estuarine chemical cues （offshore water） or contained odors from aquatic vegetation or known predators. In the absence of chemical odors, larvae oriented toward and juveniles moved away from dark horizons subtending angles 〉 60~. When placed in water containing chemical odors from potential nursery habitats, including the seagrasses Halodule wrightii and Syringodium filiforme, crabs reversed their direction of orientation relative to their responses in offshore water. Odors from two known predators, the mummichug Fundulus grandis and blue crab Callinectes sapidus, had no affect on the orientation of larvae. Yet, juveniles responded to both odors by moving toward the visual target. Results support the hypothesis that the visual orientation of larval and juvenile horseshoe crabs changes upon exposure to habitat and predator cues and that the direction of the response undergoes an ontogenetic shift following metamorphosis
文摘In nature hummingbirds face floral resources whose availability, quality and quantity can vary spatially and temporally. Thus, they must constantly make foraging decisions about which patches, plants and flowers to visit, partly as a function of the nectar reward. The uncertainty of these decisions would possibly be reduced if an individual could remember locations or use visual cues to avoid revisiting recently depleted flowers. In the present study, we carried out field experiments with white-eared hummingbirds Hylocharis leucotis, to evaluate their use of locations or visual cues when foraging on natural flowers Penstemon roseus. We evaluated the use of spatial memory by observing birds while they were foraging between two plants and within a single plant. Our results showed that hummingbirds prefer to use location when foraging in two plants, but they also use visual cues to efficiently locate unvisited rewarded flowers when they feed on a single plant. However, in absence of visual cues, in both experiments birds mainly used the location of previously visited flowers to make subsequent visits. Our data suggest that hummingbirds are capable of learning and employing this flexibility depending on the faced environmental conditions and the information acquired in previous visits [Current Zoology 57 （4）： 468-476, 2011].
基金Supported by the Key Program of National Natural Science Foundation of China(60634030)Research Fund for the Doctoral Program of Higher Education of China(20060699032)+1 种基金Aero-science Fund(2007ZC53037)Foundation of National Laboratory of Pattern Recognition(1M99G50)of China
文摘This paper presents a system that is able to reliably track multiple faces under varying poses(tilted and rotated)in real time.The system consists of two interactive modules.The first module performs the detection of the face that is subject to rotation. The second module carries out online learning-based face tracking.A mechanism that switches between the two modules is embedded into the system to automatically decide the best strategy for reliable tracking.The mechanism enables a smooth transit between the detection and tracking modules when one of them gives either nil or unreliable results.Extensive experiments demonstrate that the system can reliably carry out real time tracking of multiple faces in a complex background under different conditions such as out-of-plane rotation,tilting,fast nonlinear motion,partial occlusion,large scale changes,and camera motion.Moreover,it runs at a high speed of 10～12 frames per second(fps)for an image of 320×240.
基金Philosophy and Social Science Planning Project(Zhanjiang,2023):Research on School Adaptation Situation and Influencing Factors of Children with Autism Learning in Regular Class(ZJ23YB60)Peak-Building Project for the High-Quality Development of Basic Education(Lingnan Normal University,2023):Research on School Adaptation Situation and Influencing Factors of Preschool Children with Autism(JCJYZD202303)。
文摘The formation of self-care ability is the first step for children with autism to enter the society,and it is also a prerequisite and guarantee for their independent survival.This study aimed to explore the impact of visual cue strategies on the self-care ability of children with autism.Based on the ABA design of a single case study,this research conducted a four-month intervention on a seven-year-old child with autism via visual cue strategy as independent variables and sock-wearing skills as dependent variables,in order to explore the effect of visual cue strategy on self-care ability of children with autism.It turned out that visual cue strategy exerts a positive immediate sustained effect and social validity on the self-care ability of children with autism.Lastly,suggestions were provided for future related research based on the research process,results,and limitations.
文摘To improve the reliability and accuracy of visual tracker,a robust visual tracking algorithm based on multi-cues fusion under Bayesian framework is proposed.The weighed color and texture cues of the object are applied to describe the moving object.An adjustable observation model is incorporated into particle filtering,which utilizes the properties of particle filter for coping with non-linear,non-Gaussian assumption and the ability to predict the position of the moving object in a cluttered environment and two complementary attributes are employed to estimate the matching similarity dynamically in term of the likelihood ratio factors;furthermore tunes the weight values according to the confidence map of the color and texture feature on-line adaptively to reconfigure the optimal observation likelihood model,which ensured attaining the maximum likelihood ratio in the tracking scenario even if in the situations where the object is occluded or illumination,pose and scale are time-variant.The experimental result shows that the algorithm can track a moving object accurately while the reliability of tracking in a challenging case is validated in the experimentation.
文摘Mechanisms of predator detection and the influence of the presence of nonlethal predators on antipredator defense behavior and metamorphic traits were studied in the Indian tree frog, Polypedates maculatus. Exposure of P. maculatus tadpoles to chemical cues of caged predator（crabs, Barytelphusa spp.） fed with either conspecific or heterogeneric tadpoles, or were starved elicited defense behavior（by avoiding predator zone） in them. Such a behavior was not evident when exposed to predators housed in a glass beaker（visual cues）. Both early（Gosner stage 27–28） and later（Gosner stage 35–36） stage tadpoles when exposed to caged predators（fed with conspecific tadpoles）, prey tadpoles spent less time swimming and remained motionless for longer periods. Yet, the time spent by prey in feeding was unaffected. Further, the predator avoidance behavior exhibited by them was of the same intensity regardless of whether the caged predators were fed or starved implying the influence of predator＇s kairomones. Tadpoles reared with caged predator reached the metamorphic climax stage（MC stage; Gosner stage 42） earlier than those reared without a predator. Size at emergence（Gosner stage 46） was comparable in both the groups. The findings suggest that P. maculatus tadpoles assess predation risk chiefly by sensing kairomones of the predator in eliciting antipredator defense behaviors. Accelerated development and early metamorphosis without any compromise of the size at emergence may be due to their unaltered feeding activity.
文摘在航空发动机可视化协同维修中,利用声音提示技术,通过改进的梅尔频率倒谱系数(Mel Frequency Cepstral Coefficients,MFCC)与头相关传递函数(Head-Related Transfer Function,HRTF)构建“频域-空间”双重映射模型,实现故障声纹特征的精准提取与三维声场定位。结合增强现实界面,设计多故障优先级动态调控机制,优化声学信息传递链。实验结果表明,将声音提示技术应用于航空发动机可视化协同维修,故障维修响应时间缩短至1.3 s以内,故障定位误差控制在±1.0 mm和±1.0°,同时显著减少了协同误判频次,提升了航空发动机维修的实时性与准确性。
文摘为了解辅助沟通系统(augmentative and alternative communication,AAC)介入三部曲模式教学对提升少口语重度孤独症谱系障碍(autism spectrum disorder,ASD)成人简单社交沟通的效果,选取一名少口语重度ASD成人为个案,依其学习特质采用行动研究法,通过搜集教学评量结果的量化资料,以及研究者、个案的同学和朋友、个案母亲及沟通伙伴的质性观察资料,研究旨在通过教学提升个案在搭乘出租车活动时的功能性词汇、句构能力及类化至自然情境的能力。研究结果显示,AAC介入三部曲模式可增进少口语重度ASD成人的简单社交沟通表现。长期使用AAC的经验让个案对于新主题有自主性,在功能性词汇及句构学习方面能够参与教学规划。AAC介入三部曲模式对个案应有持续且长期的介入,除沟通成效外,亦对提升自主性及活动参与独立程度有所助益。
