I want what you've got: Cross platform portabiity and human-robot interaction assessment.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Julie L. Marble, Ph.D.*.; Douglas A. Few; David J. Bruemmer

2005-08-01

Human-robot interaction is a subtle, yet critical aspect of design that must be assessed during the development of both the human-robot interface and robot behaviors if the human-robot team is to effectively meet the complexities of the task environment. Testing not only ensures that the system can successfully achieve the tasks for which it was designed, but more importantly, usability testing allows the designers to understand how humans and robots can, will, and should work together to optimize workload distribution. A lack of human-centered robot interface design, the rigidity of sensor configuration, and the platform-specific nature of research robot developmentmore » environments are a few factors preventing robotic solutions from reaching functional utility in real word environments. Often the difficult engineering challenge of implementing adroit reactive behavior, reliable communication, trustworthy autonomy that combines with system transparency and usable interfaces is overlooked in favor of other research aims. The result is that many robotic systems never reach a level of functional utility necessary even to evaluate the efficacy of the basic system, much less result in a system that can be used in a critical, real-world environment. Further, because control architectures and interfaces are often platform specific, it is difficult or even impossible to make usability comparisons between them. This paper discusses the challenges inherent to the conduct of human factors testing of variable autonomy control architectures and across platforms within a complex, real-world environment. It discusses the need to compare behaviors, architectures, and interfaces within a structured environment that contains challenging real-world tasks, and the implications for system acceptance and trust of autonomous robotic systems for how humans and robots interact in true interactive teams.« less

The utility of the AusEd driving simulator in the clinical assessment of driver fatigue.

PubMed

Desai, Anup V; Wilsmore, Brad; Bartlett, Delwyn J; Unger, Gunnar; Constable, Ben; Joffe, David; Grunstein, Ronald R

2007-08-01

Several driving simulators have been developed which range in complexity from PC based driving tasks to advanced "real world" simulators. The AusEd driving simulator is a PC based task, which was designed to be conducive to and test for driver fatigue. This paper describes the AusEd driving simulator in detail, including the technical requirements, hardware, screen and file outputs, and analysis software. Some aspects of the test are standardized, while others can be modified to suit the experimental situation. The AusEd driving simulator is sensitive to performance decrement from driver fatigue in the laboratory setting, potentially making it useful as a laboratory or office based test for driver fatigue risk management. However, more research is still needed to correlate laboratory based simulator performance with real world driving performance and outcomes.

Motor learning from virtual reality to natural environments in individuals with Duchenne muscular dystrophy.

PubMed

Quadrado, Virgínia Helena; Silva, Talita Dias da; Favero, Francis Meire; Tonks, James; Massetti, Thais; Monteiro, Carlos Bandeira de Mello

2017-11-10

To examine whether performance improvements in the virtual environment generalize to the natural environment. we had 64 individuals, 32 of which were individuals with DMD and 32 were typically developing individuals. The groups practiced two coincidence timing tasks. In the more tangible button-press task, the individuals were required to 'intercept' a falling virtual object at the moment it reached the interception point by pressing a key on the computer. In the more abstract task, they were instructed to 'intercept' the virtual object by making a hand movement in a virtual environment using a webcam. For individuals with DMD, conducting a coincidence timing task in a virtual environment facilitated transfer to the real environment. However, we emphasize that a task practiced in a virtual environment should have higher rates of difficulties than a task practiced in a real environment. IMPLICATIONS FOR REHABILITATION Virtual environments can be used to promote improved performance in ?real-world? environments. Virtual environments offer the opportunity to create paradigms similar ?real-life? tasks, however task complexity and difficulty levels can be manipulated, graded and enhanced to increase likelihood of success in transfer of learning and performance. Individuals with DMD, in particular, showed immediate performance benefits after using virtual reality.

The STEP model: Characterizing simultaneous time effects on practice for flight simulator performance among middle-aged and older pilots

PubMed Central

Kennedy, Quinn; Taylor, Joy; Noda, Art; Yesavage, Jerome; Lazzeroni, Laura C.

2015-01-01

Understanding the possible effects of the number of practice sessions (practice) and time between practice sessions (interval) among middle-aged and older adults in real world tasks has important implications for skill maintenance. Prior training and cognitive ability may impact practice and interval effects on real world tasks. In this study, we took advantage of existing practice data from five simulated flights among 263 middle-aged and older pilots with varying levels of flight expertise (defined by FAA proficiency ratings). We developed a new STEP (Simultaneous Time Effects on Practice) model to: (1) model the simultaneous effects of practice and interval on performance of the five flights, and (2) examine the effects of selected covariates (age, flight expertise, and three composite measures of cognitive ability). The STEP model demonstrated consistent positive practice effects, negative interval effects, and predicted covariate effects. Age negatively moderated the beneficial effects of practice. Additionally, cognitive processing speed and intra-individual variability (IIV) in processing speed moderated the benefits of practice and/or the negative influence of interval for particular flight performance measures. Expertise did not interact with either practice or interval. Results indicate that practice and interval effects occur in simulated flight tasks. However, processing speed and IIV may influence these effects, even among high functioning adults. Results have implications for the design and assessment of training interventions targeted at middle-aged and older adults for complex real world tasks. PMID:26280383

Over the hill at 24: persistent age-related cognitive-motor decline in reaction times in an ecologically valid video game task begins in early adulthood.

PubMed

Thompson, Joseph J; Blair, Mark R; Henrey, Andrew J

2014-01-01

Typically studies of the effects of aging on cognitive-motor performance emphasize changes in elderly populations. Although some research is directly concerned with when age-related decline actually begins, studies are often based on relatively simple reaction time tasks, making it impossible to gauge the impact of experience in compensating for this decline in a real world task. The present study investigates age-related changes in cognitive motor performance through adolescence and adulthood in a complex real world task, the real-time strategy video game StarCraft 2. In this paper we analyze the influence of age on performance using a dataset of 3,305 players, aged 16-44, collected by Thompson, Blair, Chen & Henrey [1]. Using a piecewise regression analysis, we find that age-related slowing of within-game, self-initiated response times begins at 24 years of age. We find no evidence for the common belief expertise should attenuate domain-specific cognitive decline. Domain-specific response time declines appear to persist regardless of skill level. A second analysis of dual-task performance finds no evidence of a corresponding age-related decline. Finally, an exploratory analyses of other age-related differences suggests that older participants may have been compensating for a loss in response speed through the use of game mechanics that reduce cognitive load.

Over the Hill at 24: Persistent Age-Related Cognitive-Motor Decline in Reaction Times in an Ecologically Valid Video Game Task Begins in Early Adulthood

PubMed Central

Thompson, Joseph J.; Blair, Mark R.; Henrey, Andrew J.

2014-01-01

Typically studies of the effects of aging on cognitive-motor performance emphasize changes in elderly populations. Although some research is directly concerned with when age-related decline actually begins, studies are often based on relatively simple reaction time tasks, making it impossible to gauge the impact of experience in compensating for this decline in a real world task. The present study investigates age-related changes in cognitive motor performance through adolescence and adulthood in a complex real world task, the real-time strategy video game StarCraft 2. In this paper we analyze the influence of age on performance using a dataset of 3,305 players, aged 16-44, collected by Thompson, Blair, Chen & Henrey [1]. Using a piecewise regression analysis, we find that age-related slowing of within-game, self-initiated response times begins at 24 years of age. We find no evidence for the common belief expertise should attenuate domain-specific cognitive decline. Domain-specific response time declines appear to persist regardless of skill level. A second analysis of dual-task performance finds no evidence of a corresponding age-related decline. Finally, an exploratory analyses of other age-related differences suggests that older participants may have been compensating for a loss in response speed through the use of game mechanics that reduce cognitive load. PMID:24718593

Transfer of skill engendered by complex task training under conditions of variable priority.

PubMed

Boot, Walter R; Basak, Chandramallika; Erickson, Kirk I; Neider, Mark; Simons, Daniel J; Fabiani, Monica; Gratton, Gabriele; Voss, Michelle W; Prakash, Ruchika; Lee, HyunKyu; Low, Kathy A; Kramer, Arthur F

2010-11-01

We explored the theoretical underpinnings of a commonly used training strategy by examining issues of training and transfer of skill in the context of a complex video game (Space Fortress, Donchin, 1989). Participants trained using one of two training regimens: Full Emphasis Training (FET) or Variable Priority Training (VPT). Transfer of training was assessed with a large battery of cognitive and psychomotor tasks ranging from basic laboratory paradigms measuring reasoning, memory, and attention to complex real-world simulations. Consistent with previous studies, VPT accelerated learning and maximized task mastery. However, the hypothesis that VPT would result in broader transfer of training received limited support. Rather, transfer was most evident in tasks that were most similar to the Space Fortress game itself. Results are discussed in terms of potential limitations of the VPT approach. Copyright © 2010 Elsevier B.V. All rights reserved.

Real-time evaluation and visualization of learner performance in a mixed-reality environment for clinical breast examination.

PubMed

Kotranza, Aaron; Lind, D Scott; Lok, Benjamin

2012-07-01

We investigate the efficacy of incorporating real-time feedback of user performance within mixed-reality environments (MREs) for training real-world tasks with tightly coupled cognitive and psychomotor components. This paper presents an approach to providing real-time evaluation and visual feedback of learner performance in an MRE for training clinical breast examination (CBE). In a user study of experienced and novice CBE practitioners (n = 69), novices receiving real-time feedback performed equivalently or better than more experienced practitioners in the completeness and correctness of the exam. A second user study (n = 8) followed novices through repeated practice of CBE in the MRE. Results indicate that skills improvement in the MRE transfers to the real-world task of CBE of human patients. This initial case study demonstrates the efficacy of MREs incorporating real-time feedback for training real-world cognitive-psychomotor tasks.

Caffeine Enhances Real-World Language Processing: Evidence from a Proofreading Task

ERIC Educational Resources Information Center

Brunye, Tad T.; Mahoney, Caroline R.; Rapp, David N.; Ditman, Tali; Taylor, Holly A.

2012-01-01

Caffeine has become the most prevalently consumed psychostimulant in the world, but its influences on daily real-world functioning are relatively unknown. The present work investigated the effects of caffeine (0 mg, 100 mg, 200 mg, 400 mg) on a commonplace language task that required readers to identify and correct 4 error types in extended…

Debating complexity in modeling

USGS Publications Warehouse

Hunt, Randall J.; Zheng, Chunmiao

1999-01-01

As scientists trying to understand the natural world, how should our effort be apportioned? We know that the natural world is characterized by complex and interrelated processes. Yet do we need to explicitly incorporate these intricacies to perform the tasks we are charged with? In this era of expanding computer power and development of sophisticated preprocessors and postprocessors, are bigger machines making better models? Put another way, do we understand the natural world better now with all these advancements in our simulation ability? Today the public's patience for long-term projects producing indeterminate results is wearing thin. This increases pressure on the investigator to use the appropriate technology efficiently. On the other hand, bringing scientific results into the legal arena opens up a new dimension to the issue: to the layperson, a tool that includes more of the complexity known to exist in the real world is expected to provide the more scientifically valid answer.

Set as an Instance of a Real-World Visual-Cognitive Task

ERIC Educational Resources Information Center

Nyamsuren, Enkhbold; Taatgen, Niels A.

2013-01-01

Complex problem solving is often an integration of perceptual processing and deliberate planning. But what balances these two processes, and how do novices differ from experts? We investigate the interplay between these two in the game of SET. This article investigates how people combine bottom-up visual processes and top-down planning to succeed…

The Effects of Complexity, Accuracy, and Fluency on Communicative Adequacy in Oral Task Performance

ERIC Educational Resources Information Center

Révész, Andrea; Ekiert, Monika; Torgersen, Eivind Nessa

2016-01-01

Communicative adequacy is a key construct in second language research, as the primary goal of most language learners is to communicate successfully in real-world situations. Nevertheless, little is known about what linguistic features contribute to communicatively adequate speech. This study fills this gap by investigating the extent to which…

Extending the limits of complex learning in organic amnesia: computer training in a vocational domain.

PubMed

Glisky, E L; Schacter, D L

1989-01-01

This study explored the limits of learning that could be achieved by an amnesic patient in a complex real-world domain. Using a cuing procedure known as the method of vanishing cues, a severely amnesic encephalitic patient was taught over 250 discrete pieces of new information concerning the rules and procedures for performing a task involving data entry into a computer. Subsequently, she was able to use this acquired knowledge to perform the task accurately and efficiently in the workplace. These results suggest that amnesic patients' preserved learning abilities can be extended well beyond what has been reported previously.

The STEP model: Characterizing simultaneous time effects on practice for flight simulator performance among middle-aged and older pilots.

PubMed

Kennedy, Quinn; Taylor, Joy; Noda, Art; Yesavage, Jerome; Lazzeroni, Laura C

2015-09-01

Understanding the possible effects of the number of practice sessions (practice) and time between practice sessions (interval) among middle-aged and older adults in real-world tasks has important implications for skill maintenance. Prior training and cognitive ability may impact practice and interval effects on real-world tasks. In this study, we took advantage of existing practice data from 5 simulated flights among 263 middle-aged and older pilots with varying levels of flight expertise (defined by U.S. Federal Aviation Administration proficiency ratings). We developed a new Simultaneous Time Effects on Practice (STEP) model: (a) to model the simultaneous effects of practice and interval on performance of the 5 flights, and (b) to examine the effects of selected covariates (i.e., age, flight expertise, and 3 composite measures of cognitive ability). The STEP model demonstrated consistent positive practice effects, negative interval effects, and predicted covariate effects. Age negatively moderated the beneficial effects of practice. Additionally, cognitive processing speed and intraindividual variability (IIV) in processing speed moderated the benefits of practice and/or the negative influence of interval for particular flight performance measures. Expertise did not interact with practice or interval. Results indicated that practice and interval effects occur in simulated flight tasks. However, processing speed and IIV may influence these effects, even among high-functioning adults. Results have implications for the design and assessment of training interventions targeted at middle-aged and older adults for complex real-world tasks. (c) 2015 APA, all rights reserved).

Leadership emergence in engineering design teams.

PubMed

Guastello, Stephen J

2011-01-01

Leaders emerge from leaderless groups as part of a more complex emerging social structure. Several studies have shown that the emerging structure is aptly described by a swallowtail catastrophe model where the control parameters differ depending on whether creative problem solving, production, coordination-intensive, or emergency management groups are involved. The present study explored creative problem solving further where the participants were engaged in real-world tasks extending over several months rather than short laboratory tasks. Participants were engineering students who were organized into groups of to people who designed, built, and tested a prototype product that would solve a real-world problem. At the th week of work they completed a questionnaire indicating who was most like the leader of their group, second most like the leader, along with other questions about individuals' contributions to the group process. Results showed that the swallowtail model (R = .) exhibited a strong advantage over the linear alternative model (R = .) for predicting leadership emergence. The three control variables were control of the task, creative contributions to the group's work, and facilitating the creative contributions of others.

Robot-assisted surgery: an emerging platform for human neuroscience research

PubMed Central

Jarc, Anthony M.; Nisky, Ilana

2015-01-01

Classic studies in human sensorimotor control use simplified tasks to uncover fundamental control strategies employed by the nervous system. Such simple tasks are critical for isolating specific features of motor, sensory, or cognitive processes, and for inferring causality between these features and observed behavioral changes. However, it remains unclear how these theories translate to complex sensorimotor tasks or to natural behaviors. Part of the difficulty in performing such experiments has been the lack of appropriate tools for measuring complex motor skills in real-world contexts. Robot-assisted surgery (RAS) provides an opportunity to overcome these challenges by enabling unobtrusive measurements of user behavior. In addition, a continuum of tasks with varying complexity—from simple tasks such as those in classic studies to highly complex tasks such as a surgical procedure—can be studied using RAS platforms. Finally, RAS includes a diverse participant population of inexperienced users all the way to expert surgeons. In this perspective, we illustrate how the characteristics of RAS systems make them compelling platforms to extend many theories in human neuroscience, as well as, to develop new theories altogether. PMID:26089785

Modes of Interaction between Individuals Dominate the Topologies of Real World Networks

PubMed Central

Lee, Insuk; Kim, Eiru; Marcotte, Edward M.

2015-01-01

We find that the topologies of real world networks, such as those formed within human societies, by the Internet, or among cellular proteins, are dominated by the mode of the interactions considered among the individuals. Specifically, a major dichotomy in previously studied networks arises from modeling networks in terms of pairwise versus group tasks. The former often intrinsically give rise to scale-free, disassortative, hierarchical networks, whereas the latter often give rise to single- or broad-scale, assortative, nonhierarchical networks. These dependencies explain contrasting observations among previous topological analyses of real world complex systems. We also observe this trend in systems with natural hierarchies, in which alternate representations of the same networks, but which capture different levels of the hierarchy, manifest these signature topological differences. For example, in both the Internet and cellular proteomes, networks of lower-level system components (routers within domains or proteins within biological processes) are assortative and nonhierarchical, whereas networks of upper-level system components (internet domains or biological processes) are disassortative and hierarchical. Our results demonstrate that network topologies of complex systems must be interpreted in light of their hierarchical natures and interaction types. PMID:25793969

Representing and Enacting Movement: The Body as an Instructional Resource in a Simulator-Based Environment

ERIC Educational Resources Information Center

Sellberg, Charlott

2017-01-01

Simulators are used to practice in a safe setting before training in a safety-critical environment. Since the nature of situations encountered in high-risk domains is complex and dynamic, it is considered important for the simulation to resemble conditions of real world tasks. For this reason, simulation-based training is often discussed in terms…

Are We Ready for Real-world Neuroscience?

PubMed

Matusz, Pawel J; Dikker, Suzanne; Huth, Alexander G; Perrodin, Catherine

2018-06-19

Real-world environments are typically dynamic, complex, and multisensory in nature and require the support of top-down attention and memory mechanisms for us to be able to drive a car, make a shopping list, or pour a cup of coffee. Fundamental principles of perception and functional brain organization have been established by research utilizing well-controlled but simplified paradigms with basic stimuli. The last 30 years ushered a revolution in computational power, brain mapping, and signal processing techniques. Drawing on those theoretical and methodological advances, over the years, research has departed more and more from traditional, rigorous, and well-understood paradigms to directly investigate cognitive functions and their underlying brain mechanisms in real-world environments. These investigations typically address the role of one or, more recently, multiple attributes of real-world environments. Fundamental assumptions about perception, attention, or brain functional organization have been challenged-by studies adapting the traditional paradigms to emulate, for example, the multisensory nature or varying relevance of stimulation or dynamically changing task demands. Here, we present the state of the field within the emerging heterogeneous domain of real-world neuroscience. To be precise, the aim of this Special Focus is to bring together a variety of the emerging "real-world neuroscientific" approaches. These approaches differ in their principal aims, assumptions, or even definitions of "real-world neuroscience" research. Here, we showcase the commonalities and distinctive features of the different "real-world neuroscience" approaches. To do so, four early-career researchers and the speakers of the Cognitive Neuroscience Society 2017 Meeting symposium under the same title answer questions pertaining to the added value of such approaches in bringing us closer to accurate models of functional brain organization and cognitive functions.

Evaluation of procedural learning transfer from a virtual environment to a real situation: a case study on tank maintenance training.

PubMed

Ganier, Franck; Hoareau, Charlotte; Tisseau, Jacques

2014-01-01

Virtual reality opens new opportunities for operator training in complex tasks. It lowers costs and has fewer constraints than traditional training. The ultimate goal of virtual training is to transfer knowledge gained in a virtual environment to an actual real-world setting. This study tested whether a maintenance procedure could be learnt equally well by virtual-environment and conventional training. Forty-two adults were divided into three equally sized groups: virtual training (GVT® [generic virtual training]), conventional training (using a real tank suspension and preparation station) and control (no training). Participants then performed the procedure individually in the real environment. Both training types (conventional and virtual) produced similar levels of performance when the procedure was carried out in real conditions. Performance level for the two trained groups was better in terms of success and time taken to complete the task, time spent consulting job instructions and number of times the instructor provided guidance.

Hierarchical Event Descriptors (HED): Semi-Structured Tagging for Real-World Events in Large-Scale EEG

PubMed Central

Bigdely-Shamlo, Nima; Cockfield, Jeremy; Makeig, Scott; Rognon, Thomas; La Valle, Chris; Miyakoshi, Makoto; Robbins, Kay A.

2016-01-01

Real-world brain imaging by EEG requires accurate annotation of complex subject-environment interactions in event-rich tasks and paradigms. This paper describes the evolution of the Hierarchical Event Descriptor (HED) system for systematically describing both laboratory and real-world events. HED version 2, first described here, provides the semantic capability of describing a variety of subject and environmental states. HED descriptions can include stimulus presentation events on screen or in virtual worlds, experimental or spontaneous events occurring in the real world environment, and events experienced via one or multiple sensory modalities. Furthermore, HED 2 can distinguish between the mere presence of an object and its actual (or putative) perception by a subject. Although the HED framework has implicit ontological and linked data representations, the user-interface for HED annotation is more intuitive than traditional ontological annotation. We believe that hiding the formal representations allows for a more user-friendly interface, making consistent, detailed tagging of experimental, and real-world events possible for research users. HED is extensible while retaining the advantages of having an enforced common core vocabulary. We have developed a collection of tools to support HED tag assignment and validation; these are available at hedtags.org. A plug-in for EEGLAB (sccn.ucsd.edu/eeglab), CTAGGER, is also available to speed the process of tagging existing studies. PMID:27799907

Effects of transcranial direct current stimulation (tDCS) on multiscale complexity of dual-task postural control in older adults.

PubMed

Zhou, Diange; Zhou, Junhong; Chen, Hu; Manor, Brad; Lin, Jianhao; Zhang, Jue

2015-08-01

Transcranial direct current stimulation (tDCS) targeting the prefrontal cortex reduces the size and speed of standing postural sway in younger adults, particularly when performing a cognitive dual task. Here, we hypothesized that tDCS would alter the complex dynamics of postural sway as quantified by multiscale entropy (MSE). Twenty healthy older adults completed two study visits. Center-of-pressure (COP) fluctuations were recorded during single-task (i.e., quiet standing) and dual-task (i.e., standing while performing serial subtractions) conditions, both before and after a 20-min session of real or sham tDCS. MSE was used to estimate COP complexity within each condition. The percentage change in complexity from single- to dual-task conditions (i.e., dual-task cost) was also calculated. Before tDCS, COP complexity was lower (p = 0.04) in the dual-task condition as compared to the single-task condition. Neither real nor sham tDCS altered complexity in the single-task condition. As compared to sham tDCS, real tDCS increased complexity in the dual-task condition (p = 0.02) and induced a trend toward improved serial subtraction performance (p = 0.09). Moreover, those subjects with lower dual-task COP complexity at baseline exhibited greater percentage increases in complexity following real tDCS (R = -0.39, p = 0.05). Real tDCS also reduced the dual-task cost to complexity (p = 0.02), while sham stimulation had no effect. A single session of tDCS targeting the prefrontal cortex increased standing postural sway complexity with concurrent non-postural cognitive task. This form of noninvasive brain stimulation may be a safe strategy to acutely improve postural control by enhancing the system's capacity to adapt to stressors.

Social Justice and Proportional Reasoning

ERIC Educational Resources Information Center

Simic-Muller, Ksenija

2015-01-01

Ratio and proportional reasoning tasks abound that have connections to real-world situations. Examples in this article demonstrate how textbook tasks can easily be transformed into authentic real-world problems that shed light on issues of equity and fairness, such as population growth and crime rates. A few ideas are presented on how teachers can…

Hidden Markov model analysis of force/torque information in telemanipulation

NASA Technical Reports Server (NTRS)

Hannaford, Blake; Lee, Paul

1991-01-01

A model for the prediction and analysis of sensor information recorded during robotic performance of telemanipulation tasks is presented. The model uses the hidden Markov model to describe the task structure, the operator's or intelligent controller's goal structure, and the sensor signals. A methodology for constructing the model parameters based on engineering knowledge of the task is described. It is concluded that the model and its optimal state estimation algorithm, the Viterbi algorithm, are very succesful at the task of segmenting the data record into phases corresponding to subgoals of the task. The model provides a rich modeling structure within a statistical framework, which enables it to represent complex systems and be robust to real-world sensory signals.

Classification of complex networks based on similarity of topological network features

NASA Astrophysics Data System (ADS)

Attar, Niousha; Aliakbary, Sadegh

2017-09-01

Over the past few decades, networks have been widely used to model real-world phenomena. Real-world networks exhibit nontrivial topological characteristics and therefore, many network models are proposed in the literature for generating graphs that are similar to real networks. Network models reproduce nontrivial properties such as long-tail degree distributions or high clustering coefficients. In this context, we encounter the problem of selecting the network model that best fits a given real-world network. The need for a model selection method reveals the network classification problem, in which a target-network is classified into one of the candidate network models. In this paper, we propose a novel network classification method which is independent of the network size and employs an alignment-free metric of network comparison. The proposed method is based on supervised machine learning algorithms and utilizes the topological similarities of networks for the classification task. The experiments show that the proposed method outperforms state-of-the-art methods with respect to classification accuracy, time efficiency, and robustness to noise.

Expert Systems in Contract Management. A Pilot Study.

DTIC Science & Technology

1985-10-01

and appropriately selected .1 ~..they can provide valuable assistance to managers in their tasks of planning and control. If these techniques are to ...the programs that would affect their relevance -> . to construction management applications in general. We also ascertained which programs have... further experience of SAVOIR applied in a fairly complex real-world domain This has, in their view, confirmed the suitability of SAVOIR for the domain

The Neurodynamics of Affect in the Laboratory Predicts Persistence of Real-World Emotional Responses.

PubMed

Heller, Aaron S; Fox, Andrew S; Wing, Erik K; McQuisition, Kaitlyn M; Vack, Nathan J; Davidson, Richard J

2015-07-22

Failure to sustain positive affect over time is a hallmark of depression and other psychopathologies, but the mechanisms supporting the ability to sustain positive emotional responses are poorly understood. Here, we investigated the neural correlates associated with the persistence of positive affect in the real world by conducting two experiments in humans: an fMRI task of reward responses and an experience-sampling task measuring emotional responses to a reward obtained in the field. The magnitude of DLPFC engagement to rewards administered in the laboratory predicted reactivity of real-world positive emotion following a reward administered in the field. Sustained ventral striatum engagement in the laboratory positively predicted the duration of real-world positive emotional responses. These results suggest that common pathways are associated with the unfolding of neural processes over seconds and with the dynamics of emotions experienced over minutes. Examining such dynamics may facilitate a better understanding of the brain-behavior associations underlying emotion. Significance statement: How real-world emotion, experienced over seconds, minutes, and hours, is instantiated in the brain over the course of milliseconds and seconds is unknown. We combined a novel, real-world experience-sampling task with fMRI to examine how individual differences in real-world emotion, experienced over minutes and hours, is subserved by affective neurodynamics of brain activity over the course of seconds. When winning money in the real world, individuals sustaining positive emotion the longest were those with the most prolonged ventral striatal activity. These results suggest that common pathways are associated with the unfolding of neural processes over seconds and with the dynamics of emotions experienced over minutes. Examining such dynamics may facilitate a better understanding of the brain-behavior associations underlying emotion. Copyright © 2015 the authors 0270-6474/15/3510503-07$15.00/0.

Effective real-time vehicle tracking using discriminative sparse coding on local patches

NASA Astrophysics Data System (ADS)

Chen, XiangJun; Ye, Feiyue; Ruan, Yaduan; Chen, Qimei

2016-01-01

A visual tracking framework that provides an object detector and tracker, which focuses on effective and efficient visual tracking in surveillance of real-world intelligent transport system applications, is proposed. The framework casts the tracking task as problems of object detection, feature representation, and classification, which is different from appearance model-matching approaches. Through a feature representation of discriminative sparse coding on local patches called DSCLP, which trains a dictionary on local clustered patches sampled from both positive and negative datasets, the discriminative power and robustness has been improved remarkably, which makes our method more robust to a complex realistic setting with all kinds of degraded image quality. Moreover, by catching objects through one-time background subtraction, along with offline dictionary training, computation time is dramatically reduced, which enables our framework to achieve real-time tracking performance even in a high-definition sequence with heavy traffic. Experiment results show that our work outperforms some state-of-the-art methods in terms of speed, accuracy, and robustness and exhibits increased robustness in a complex real-world scenario with degraded image quality caused by vehicle occlusion, image blur of rain or fog, and change in viewpoint or scale.

Perception of Graphical Virtual Environments by Blind Users via Sensory Substitution.

PubMed

Maidenbaum, Shachar; Buchs, Galit; Abboud, Sami; Lavi-Rotbain, Ori; Amedi, Amir

2016-01-01

Graphical virtual environments are currently far from accessible to blind users as their content is mostly visual. This is especially unfortunate as these environments hold great potential for this population for purposes such as safe orientation, education, and entertainment. Previous tools have increased accessibility but there is still a long way to go. Visual-to-audio Sensory-Substitution-Devices (SSDs) can increase accessibility generically by sonifying on-screen content regardless of the specific environment and offer increased accessibility without the use of expensive dedicated peripherals like electrode/vibrator arrays. Using SSDs virtually utilizes similar skills as when using them in the real world, enabling both training on the device and training on environments virtually before real-world visits. This could enable more complex, standardized and autonomous SSD training and new insights into multisensory interaction and the visually-deprived brain. However, whether congenitally blind users, who have never experienced virtual environments, will be able to use this information for successful perception and interaction within them is currently unclear.We tested this using the EyeMusic SSD, which conveys whole-scene visual information, to perform virtual tasks otherwise impossible without vision. Congenitally blind users had to navigate virtual environments and find doors, differentiate between them based on their features (Experiment1:task1) and surroundings (Experiment1:task2) and walk through them; these tasks were accomplished with a 95% and 97% success rate, respectively. We further explored the reactions of congenitally blind users during their first interaction with a more complex virtual environment than in the previous tasks-walking down a virtual street, recognizing different features of houses and trees, navigating to cross-walks, etc. Users reacted enthusiastically and reported feeling immersed within the environment. They highlighted the potential usefulness of such environments for understanding what visual scenes are supposed to look like and their potential for complex training and suggested many future environments they wished to experience.

Decision paths in complex tasks

NASA Technical Reports Server (NTRS)

Galanter, Eugene

1991-01-01

Complex real world action and its prediction and control has escaped analysis by the classical methods of psychological research. The reason is that psychologists have no procedures to parse complex tasks into their constituents. Where such a division can be made, based say on expert judgment, there is no natural scale to measure the positive or negative values of the components. Even if we could assign numbers to task parts, we lack rules i.e., a theory, to combine them into a total task representation. We compare here two plausible theories for the amalgamation of the value of task components. Both of these theories require a numerical representation of motivation, for motivation is the primary variable that guides choice and action in well-learned tasks. We address this problem of motivational quantification and performance prediction by developing psychophysical scales of the desireability or aversiveness of task components based on utility scaling methods (Galanter 1990). We modify methods used originally to scale sensory magnitudes (Stevens and Galanter 1957), and that have been applied recently to the measure of task 'workload' by Gopher and Braune (1984). Our modification uses utility comparison scaling techniques which avoid the unnecessary assumptions made by Gopher and Braune. Formula for the utility of complex tasks based on the theoretical models are used to predict decision and choice of alternate paths to the same goal.

Rational models as theories - not standards - of behavior.

PubMed

McKenzie, Craig R.M.

2003-09-01

When people's behavior in laboratory tasks systematically deviates from a rational model, the implication is that real-world performance could be improved by changing the behavior. However, recent studies suggest that behavioral violations of rational models are at least sometimes the result of strategies that are well adapted to the real world (and not necessarily to the laboratory task). Thus, even if one accepts that certain behavior in the laboratory is irrational, compelling evidence that real-world behavior ought to change accordingly is often lacking. It is suggested here that rational models be seen as theories, and not standards, of behavior.

Intraindividual variability in basic reaction time predicts middle-aged and older pilots' flight simulator performance.

PubMed

Kennedy, Quinn; Taylor, Joy; Heraldez, Daniel; Noda, Art; Lazzeroni, Laura C; Yesavage, Jerome

2013-07-01

Intraindividual variability (IIV) is negatively associated with cognitive test performance and is positively associated with age and some neurological disorders. We aimed to extend these findings to a real-world task, flight simulator performance. We hypothesized that IIV predicts poorer initial flight performance and increased rate of decline in performance among middle-aged and older pilots. Two-hundred and thirty-six pilots (40-69 years) completed annual assessments comprising a cognitive battery and two 75-min simulated flights in a flight simulator. Basic and complex IIV composite variables were created from measures of basic reaction time and shifting and divided attention tasks. Flight simulator performance was characterized by an overall summary score and scores on communication, emergencies, approach, and traffic avoidance components. Although basic IIV did not predict rate of decline in flight performance, it had a negative association with initial performance for most flight measures. After taking into account processing speed, basic IIV explained an additional 8%-12% of the negative age effect on initial flight performance. IIV plays an important role in real-world tasks and is another aspect of cognition that underlies age-related differences in cognitive performance.

Intraindividual Variability in Basic Reaction Time Predicts Middle-Aged and Older Pilots’ Flight Simulator Performance

PubMed Central

2013-01-01

Objectives. Intraindividual variability (IIV) is negatively associated with cognitive test performance and is positively associated with age and some neurological disorders. We aimed to extend these findings to a real-world task, flight simulator performance. We hypothesized that IIV predicts poorer initial flight performance and increased rate of decline in performance among middle-aged and older pilots. Method. Two-hundred and thirty-six pilots (40–69 years) completed annual assessments comprising a cognitive battery and two 75-min simulated flights in a flight simulator. Basic and complex IIV composite variables were created from measures of basic reaction time and shifting and divided attention tasks. Flight simulator performance was characterized by an overall summary score and scores on communication, emergencies, approach, and traffic avoidance components. Results. Although basic IIV did not predict rate of decline in flight performance, it had a negative association with initial performance for most flight measures. After taking into account processing speed, basic IIV explained an additional 8%–12% of the negative age effect on initial flight performance. Discussion. IIV plays an important role in real-world tasks and is another aspect of cognition that underlies age-related differences in cognitive performance. PMID:23052365

Robust Fixed-Structure Controller Synthesis

NASA Technical Reports Server (NTRS)

Corrado, Joseph R.; Haddad, Wassim M.; Gupta, Kajal (Technical Monitor)

2000-01-01

The ability to develop an integrated control system design methodology for robust high performance controllers satisfying multiple design criteria and real world hardware constraints constitutes a challenging task. The increasingly stringent performance specifications required for controlling such systems necessitates a trade-off between controller complexity and robustness. The principle challenge of the minimal complexity robust control design is to arrive at a tractable control design formulation in spite of the extreme complexity of such systems. Hence, design of minimal complexitY robust controllers for systems in the face of modeling errors has been a major preoccupation of system and control theorists and practitioners for the past several decades.

Application of real-time machine learning to myoelectric prosthesis control: A case series in adaptive switching.

PubMed

Edwards, Ann L; Dawson, Michael R; Hebert, Jacqueline S; Sherstan, Craig; Sutton, Richard S; Chan, K Ming; Pilarski, Patrick M

2016-10-01

Myoelectric prostheses currently used by amputees can be difficult to control. Machine learning, and in particular learned predictions about user intent, could help to reduce the time and cognitive load required by amputees while operating their prosthetic device. The goal of this study was to compare two switching-based methods of controlling a myoelectric arm: non-adaptive (or conventional) control and adaptive control (involving real-time prediction learning). Case series study. We compared non-adaptive and adaptive control in two different experiments. In the first, one amputee and one non-amputee subject controlled a robotic arm to perform a simple task; in the second, three able-bodied subjects controlled a robotic arm to perform a more complex task. For both tasks, we calculated the mean time and total number of switches between robotic arm functions over three trials. Adaptive control significantly decreased the number of switches and total switching time for both tasks compared with the conventional control method. Real-time prediction learning was successfully used to improve the control interface of a myoelectric robotic arm during uninterrupted use by an amputee subject and able-bodied subjects. Adaptive control using real-time prediction learning has the potential to help decrease both the time and the cognitive load required by amputees in real-world functional situations when using myoelectric prostheses. © The International Society for Prosthetics and Orthotics 2015.

Prospective, randomized assessment of transfer of training (ToT) and transfer effectiveness ratio (TER) of virtual reality simulation training for laparoscopic skill acquisition.

PubMed

Gallagher, Anthony G; Seymour, Neal E; Jordan-Black, Julie-Anne; Bunting, Brendan P; McGlade, Kieran; Satava, Richard Martin

2013-06-01

We assessed the effectiveness of ToT from VR laparoscopic simulation training in 2 studies. In a second study, we also assessed the TER. ToT is a detectable performance improvement between equivalent groups, and TER is the observed percentage performance differences between 2 matched groups carrying out the same task but with 1 group pretrained on VR simulation. Concordance between simulated and in-vivo procedure performance was also assessed. Prospective, randomized, and blinded. In Study 1, experienced laparoscopic surgeons (n = 195) and in Study 2 laparoscopic novices (n = 30) were randomized to either train on VR simulation before completing an equivalent real-world task or complete the real-world task only. Experienced laparoscopic surgeons and novices who trained on the simulator performed significantly better than their controls, thus demonstrating ToT. Their performance showed a TER between 7% and 42% from the virtual to the real tasks. Simulation training impacted most on procedural error reduction in both studies (32-42%). The correlation observed between the VR and real-world task performance was r > 0·96 (Study 2). VR simulation training offers a powerful and effective platform for training safer skills.

Software-safety and software quality assurance in real-time applications Part 2: Real-time structures and languages

NASA Astrophysics Data System (ADS)

Schoitsch, Erwin

1988-07-01

Our society is depending more and more on the reliability of embedded (real-time) computer systems even in every-day life. Considering the complexity of the real world, this might become a severe threat. Real-time programming is a discipline important not only in process control and data acquisition systems, but also in fields like communication, office automation, interactive databases, interactive graphics and operating systems development. General concepts of concurrent programming and constructs for process-synchronization are discussed in detail. Tasking and synchronization concepts, methods of process communication, interrupt- and timeout handling in systems based on semaphores, signals, conditional critical regions or on real-time languages like Concurrent PASCAL, MODULA, CHILL and ADA are explained and compared with each other and with respect to their potential to quality and safety.

The impact of symptomatic mild traumatic brain injury on complex everyday activities and the link with alterations in cerebral functioning: Exploratory case studies.

PubMed

Bottari, Carolina; Gosselin, Nadia; Chen, Jen-Kai; Ptito, Alain

2017-07-01

The objective of the study was to explore the neurophysiological correlates of altered functional independence using functional magnetic resonance imaging (fMRI) and event-related potentials (ERP) after a mild traumatic brain injury (mTBI). The participants consisted of three individuals with symptomatic mTBI (3.9 ± 3.6 months post-mTBI) and 12 healthy controls. The main measures used were the Instrumental Activities of Daily Living (IADL) Profile observation-based assessment; a visual externally ordered working memory task combined to event-related potentials (ERP) and fMRI recordings; neuropsychological tests; post-concussion symptoms questionnaires; and the Activities of Daily Living (ADL) Profile interview. Compared to normal controls, all three patients had difficulty with a real-world complex budgeting activity due to deficits in planning, ineffective strategy use and/or a prolonged time to detect and correct errors. Reduced activations in the right mid-dorsolateral prefrontal cortex on fMRI as well as abnormal frontal or parietal components of the ERP occurred alongside these deficits. Results of this exploratory study suggest that reduced independence in complex everyday activities in symptomatic mTBI may be at least partly explained by a decrease in brain activation in the prefrontal cortex, abnormal ERP, or slower reaction times on working memory tasks. The study presents an initial attempt at combining research in neuroscience with ecological real-world evaluation research to further our understanding of the difficulties in complex everyday activities experienced by individuals with mTBI.

Tracking dynamic team activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tambe, M.

1996-12-31

AI researchers are striving to build complex multi-agent worlds with intended applications ranging from the RoboCup robotic soccer tournaments, to interactive virtual theatre, to large-scale real-world battlefield simulations. Agent tracking - monitoring other agent`s actions and inferring their higher-level goals and intentions - is a central requirement in such worlds. While previous work has mostly focused on tracking individual agents, this paper goes beyond by focusing on agent teams. Team tracking poses the challenge of tracking a team`s joint goals and plans. Dynamic, real-time environments add to the challenge, as ambiguities have to be resolved in real-time. The central hypothesismore » underlying the present work is that an explicit team-oriented perspective enables effective team tracking. This hypothesis is instantiated using the model tracing technology employed in tracking individual agents. Thus, to track team activities, team models are put to service. Team models are a concrete application of the joint intentions framework and enable an agent to track team activities, regardless of the agent`s being a collaborative participant or a non-participant in the team. To facilitate real-time ambiguity resolution with team models: (i) aspects of tracking are cast as constraint satisfaction problems to exploit constraint propagation techniques; and (ii) a cost minimality criterion is applied to constrain tracking search. Empirical results from two separate tasks in real-world, dynamic environments one collaborative and one competitive - are provided.« less

Lessons Learned from Crowdsourcing Complex Engineering Tasks.

PubMed

Staffelbach, Matthew; Sempolinski, Peter; Kijewski-Correa, Tracy; Thain, Douglas; Wei, Daniel; Kareem, Ahsan; Madey, Gregory

2015-01-01

Crowdsourcing is the practice of obtaining needed ideas, services, or content by requesting contributions from a large group of people. Amazon Mechanical Turk is a web marketplace for crowdsourcing microtasks, such as answering surveys and image tagging. We explored the limits of crowdsourcing by using Mechanical Turk for a more complicated task: analysis and creation of wind simulations. Our investigation examined the feasibility of using crowdsourcing for complex, highly technical tasks. This was done to determine if the benefits of crowdsourcing could be harnessed to accurately and effectively contribute to solving complex real world engineering problems. Of course, untrained crowds cannot be used as a mere substitute for trained expertise. Rather, we sought to understand how crowd workers can be used as a large pool of labor for a preliminary analysis of complex data. We compared the skill of the anonymous crowd workers from Amazon Mechanical Turk with that of civil engineering graduate students, making a first pass at analyzing wind simulation data. For the first phase, we posted analysis questions to Amazon crowd workers and to two groups of civil engineering graduate students. A second phase of our experiment instructed crowd workers and students to create simulations on our Virtual Wind Tunnel website to solve a more complex task. With a sufficiently comprehensive tutorial and compensation similar to typical crowd-sourcing wages, we were able to enlist crowd workers to effectively complete longer, more complex tasks with competence comparable to that of graduate students with more comprehensive, expert-level knowledge. Furthermore, more complex tasks require increased communication with the workers. As tasks become more complex, the employment relationship begins to become more akin to outsourcing than crowdsourcing. Through this investigation, we were able to stretch and explore the limits of crowdsourcing as a tool for solving complex problems.

Perception of Graphical Virtual Environments by Blind Users via Sensory Substitution

PubMed Central

Maidenbaum, Shachar; Buchs, Galit; Abboud, Sami; Lavi-Rotbain, Ori; Amedi, Amir

2016-01-01

Graphical virtual environments are currently far from accessible to blind users as their content is mostly visual. This is especially unfortunate as these environments hold great potential for this population for purposes such as safe orientation, education, and entertainment. Previous tools have increased accessibility but there is still a long way to go. Visual-to-audio Sensory-Substitution-Devices (SSDs) can increase accessibility generically by sonifying on-screen content regardless of the specific environment and offer increased accessibility without the use of expensive dedicated peripherals like electrode/vibrator arrays. Using SSDs virtually utilizes similar skills as when using them in the real world, enabling both training on the device and training on environments virtually before real-world visits. This could enable more complex, standardized and autonomous SSD training and new insights into multisensory interaction and the visually-deprived brain. However, whether congenitally blind users, who have never experienced virtual environments, will be able to use this information for successful perception and interaction within them is currently unclear.We tested this using the EyeMusic SSD, which conveys whole-scene visual information, to perform virtual tasks otherwise impossible without vision. Congenitally blind users had to navigate virtual environments and find doors, differentiate between them based on their features (Experiment1:task1) and surroundings (Experiment1:task2) and walk through them; these tasks were accomplished with a 95% and 97% success rate, respectively. We further explored the reactions of congenitally blind users during their first interaction with a more complex virtual environment than in the previous tasks–walking down a virtual street, recognizing different features of houses and trees, navigating to cross-walks, etc. Users reacted enthusiastically and reported feeling immersed within the environment. They highlighted the potential usefulness of such environments for understanding what visual scenes are supposed to look like and their potential for complex training and suggested many future environments they wished to experience. PMID:26882473

Attention during active visual tasks: counting, pointing, or simply looking

PubMed Central

Wilder, John D.; Schnitzer, Brian S.; Gersch, Timothy M.; Dosher, Barbara A.

2009-01-01

Visual attention and saccades are typically studied in artificial situations, with stimuli presented to the steadily fixating eye, or saccades made along specified paths. By contrast, in the real world saccadic patterns are constrained only by the demands of the motivating task. We studied attention during pauses between saccades made to perform 3 free-viewing tasks: counting dots, pointing to the same dots with a visible cursor, or simply looking at the dots using a freely-chosen path. Attention was assessed by the ability to identify the orientation of a briefly-presented Gabor probe. All primary tasks produced losses in identification performance, with counting producing the largest losses, followed by pointing and then looking-only. Looking-only resulted in a 37% increase in contrast thresholds in the orientation task. Counting produced more severe losses that were not overcome by increasing Gabor contrast. Detection or localization of the Gabor, unlike identification, were largely unaffected by any of the primary tasks. Taken together, these results show that attention is required to control saccades, even with freely-chosen paths, but the attentional demands of saccades are less than those attached to tasks such as counting, which have a significant cognitive load. Counting proved to be a highly demanding task that either exhausted momentary processing capacity (e.g., working memory or executive functions), or, alternatively, encouraged a strategy of filtering out all signals irrelevant to counting itself. The fact that the attentional demands of saccades (as well as those of detection/localization) are relatively modest makes it possible to continually adjust both the spatial and temporal pattern of saccades so as to re-allocate attentional resources as needed to handle the complex and multifaceted demands of real-world environments. PMID:18649913

A Model of the Superior Colliculus Predicts Fixation Locations during Scene Viewing and Visual Search.

PubMed

Adeli, Hossein; Vitu, Françoise; Zelinsky, Gregory J

2017-02-08

Modern computational models of attention predict fixations using saliency maps and target maps, which prioritize locations for fixation based on feature contrast and target goals, respectively. But whereas many such models are biologically plausible, none have looked to the oculomotor system for design constraints or parameter specification. Conversely, although most models of saccade programming are tightly coupled to underlying neurophysiology, none have been tested using real-world stimuli and tasks. We combined the strengths of these two approaches in MASC, a model of attention in the superior colliculus (SC) that captures known neurophysiological constraints on saccade programming. We show that MASC predicted the fixation locations of humans freely viewing naturalistic scenes and performing exemplar and categorical search tasks, a breadth achieved by no other existing model. Moreover, it did this as well or better than its more specialized state-of-the-art competitors. MASC's predictive success stems from its inclusion of high-level but core principles of SC organization: an over-representation of foveal information, size-invariant population codes, cascaded population averaging over distorted visual and motor maps, and competition between motor point images for saccade programming, all of which cause further modulation of priority (attention) after projection of saliency and target maps to the SC. Only by incorporating these organizing brain principles into our models can we fully understand the transformation of complex visual information into the saccade programs underlying movements of overt attention. With MASC, a theoretical footing now exists to generate and test computationally explicit predictions of behavioral and neural responses in visually complex real-world contexts. SIGNIFICANCE STATEMENT The superior colliculus (SC) performs a visual-to-motor transformation vital to overt attention, but existing SC models cannot predict saccades to visually complex real-world stimuli. We introduce a brain-inspired SC model that outperforms state-of-the-art image-based competitors in predicting the sequences of fixations made by humans performing a range of everyday tasks (scene viewing and exemplar and categorical search), making clear the value of looking to the brain for model design. This work is significant in that it will drive new research by making computationally explicit predictions of SC neural population activity in response to naturalistic stimuli and tasks. It will also serve as a blueprint for the construction of other brain-inspired models, helping to usher in the next generation of truly intelligent autonomous systems. Copyright © 2017 the authors 0270-6474/17/371453-15$15.00/0.

Open multi-agent control architecture to support virtual-reality-based man-machine interfaces

NASA Astrophysics Data System (ADS)

Freund, Eckhard; Rossmann, Juergen; Brasch, Marcel

2001-10-01

Projective Virtual Reality is a new and promising approach to intuitively operable man machine interfaces for the commanding and supervision of complex automation systems. The user interface part of Projective Virtual Reality heavily builds on latest Virtual Reality techniques, a task deduction component and automatic action planning capabilities. In order to realize man machine interfaces for complex applications, not only the Virtual Reality part has to be considered but also the capabilities of the underlying robot and automation controller are of great importance. This paper presents a control architecture that has proved to be an ideal basis for the realization of complex robotic and automation systems that are controlled by Virtual Reality based man machine interfaces. The architecture does not just provide a well suited framework for the real-time control of a multi robot system but also supports Virtual Reality metaphors and augmentations which facilitate the user's job to command and supervise a complex system. The developed control architecture has already been used for a number of applications. Its capability to integrate sensor information from sensors of different levels of abstraction in real-time helps to make the realized automation system very responsive to real world changes. In this paper, the architecture will be described comprehensively, its main building blocks will be discussed and one realization that is built based on an open source real-time operating system will be presented. The software design and the features of the architecture which make it generally applicable to the distributed control of automation agents in real world applications will be explained. Furthermore its application to the commanding and control of experiments in the Columbus space laboratory, the European contribution to the International Space Station (ISS), is only one example which will be described.

Next Generation Real-Time Systems: Investigating the Potential of Partial-Solution Tasks.

DTIC Science & Technology

1994-12-01

insufficient for dealing with the complexities of next-generation real - time systems . New methods of intelligent control must be developed for guaranteeing...on-time task completion for real - time systems that are faced with unpredictable and dynamically changing requirements. Implementing real-time...tasks by experimentally measuring the change in performance of 11 simulated real - time systems when converted from all-or-nothing tasks to partial

Planning perception and action for cognitive mobile manipulators

NASA Astrophysics Data System (ADS)

Gaschler, Andre; Nogina, Svetlana; Petrick, Ronald P. A.; Knoll, Alois

2013-12-01

We present a general approach to perception and manipulation planning for cognitive mobile manipulators. Rather than hard-coding single purpose robot applications, a robot should be able to reason about its basic skills in order to solve complex problems autonomously. Humans intuitively solve tasks in real-world scenarios by breaking down abstract problems into smaller sub-tasks and use heuristics based on their previous experience. We apply a similar idea for planning perception and manipulation to cognitive mobile robots. Our approach is based on contingent planning and run-time sensing, integrated in our knowledge of volumes" planning framework, called KVP. Using the general-purpose PKS planner, we model information-gathering actions at plan time that have multiple possible outcomes at run time. As a result, perception and sensing arise as necessary preconditions for manipulation, rather than being hard-coded as tasks themselves. We demonstrate the e ectiveness of our approach on two scenarios covering visual and force sensing on a real mobile manipulator.

An Experimental Study of Team Size and Performance on a Complex Task.

PubMed

Mao, Andrew; Mason, Winter; Suri, Siddharth; Watts, Duncan J

2016-01-01

The relationship between team size and productivity is a question of broad relevance across economics, psychology, and management science. For complex tasks, however, where both the potential benefits and costs of coordinated work increase with the number of workers, neither theoretical arguments nor empirical evidence consistently favor larger vs. smaller teams. Experimental findings, meanwhile, have relied on small groups and highly stylized tasks, hence are hard to generalize to realistic settings. Here we narrow the gap between real-world task complexity and experimental control, reporting results from an online experiment in which 47 teams of size ranging from n = 1 to 32 collaborated on a realistic crisis mapping task. We find that individuals in teams exerted lower overall effort than independent workers, in part by allocating their effort to less demanding (and less productive) sub-tasks; however, we also find that individuals in teams collaborated more with increasing team size. Directly comparing these competing effects, we find that the largest teams outperformed an equivalent number of independent workers, suggesting that gains to collaboration dominated losses to effort. Importantly, these teams also performed comparably to a field deployment of crisis mappers, suggesting that experiments of the type described here can help solve practical problems as well as advancing the science of collective intelligence.

An Experimental Study of Team Size and Performance on a Complex Task

PubMed Central

Mao, Andrew; Mason, Winter; Suri, Siddharth; Watts, Duncan J.

2016-01-01

The relationship between team size and productivity is a question of broad relevance across economics, psychology, and management science. For complex tasks, however, where both the potential benefits and costs of coordinated work increase with the number of workers, neither theoretical arguments nor empirical evidence consistently favor larger vs. smaller teams. Experimental findings, meanwhile, have relied on small groups and highly stylized tasks, hence are hard to generalize to realistic settings. Here we narrow the gap between real-world task complexity and experimental control, reporting results from an online experiment in which 47 teams of size ranging from n = 1 to 32 collaborated on a realistic crisis mapping task. We find that individuals in teams exerted lower overall effort than independent workers, in part by allocating their effort to less demanding (and less productive) sub-tasks; however, we also find that individuals in teams collaborated more with increasing team size. Directly comparing these competing effects, we find that the largest teams outperformed an equivalent number of independent workers, suggesting that gains to collaboration dominated losses to effort. Importantly, these teams also performed comparably to a field deployment of crisis mappers, suggesting that experiments of the type described here can help solve practical problems as well as advancing the science of collective intelligence. PMID:27082239

Overlapping community detection in weighted networks via a Bayesian approach

NASA Astrophysics Data System (ADS)

Chen, Yi; Wang, Xiaolong; Xiang, Xin; Tang, Buzhou; Chen, Qingcai; Fan, Shixi; Bu, Junzhao

2017-02-01

Complex networks as a powerful way to represent complex systems have been widely studied during the past several years. One of the most important tasks of complex network analysis is to detect communities embedded in networks. In the real world, weighted networks are very common and may contain overlapping communities where a node is allowed to belong to multiple communities. In this paper, we propose a novel Bayesian approach, called the Bayesian mixture network (BMN) model, to detect overlapping communities in weighted networks. The advantages of our method are (i) providing soft-partition solutions in weighted networks; (ii) providing soft memberships, which quantify 'how strongly' a node belongs to a community. Experiments on a large number of real and synthetic networks show that our model has the ability in detecting overlapping communities in weighted networks and is competitive with other state-of-the-art models at shedding light on community partition.

Effects of age on a real-world What-Where-When memory task

PubMed Central

Mazurek, Adèle; Bhoopathy, Raja Meenakshi; Read, Jenny C. A.; Gallagher, Peter; Smulders, Tom V.

2015-01-01

Many cognitive abilities decline with aging, making it difficult to detect pathological changes against a background of natural changes in cognition. Most of the tests to assess cognitive decline are artificial tasks that have little resemblance to the problems faced by people in everyday life. This means both that people may have little practice doing such tasks (potentially contributing to the decline in performance) and that the tasks may not be good predictors of real-world cognitive problems. In this study, we test the performance of young people (18–25 years) and older people (60+-year-olds) on a novel, more ecologically valid test of episodic memory: the real-world What-Where-When (WWW) memory test. We also compare them on a battery of other cognitive tests, including working memory, psychomotor speed, executive function, and episodic memory. Older people show the expected age-related declines on the test battery. In the WWW memory task, older people were more likely to fail to remember any WWW combination than younger people were, although they did not significantly differ in their overall WWW score due to some older people performing as well as or better than most younger people. WWW memory performance was significantly predicted by other measures of episodic memory, such as the single-trial learning and long-term retention in the Rey Auditory Verbal Learning task and Combined Object Location Memory in the Object Relocation task. Self-reported memory complaints also predicted performance on the WWW task. These findings confirm that our real-world WWW memory task is a valid measure of episodic memory, with high ecological validity, which may be useful as a predictor of everyday memory abilities. The task will require a bit more development to improve its sensitivity to cognitive declines in aging and to potentially distinguish between mentally healthy older adults and those with early signs of cognitive pathologies. PMID:26042030

Sustained Attention in Real Classroom Settings: An EEG Study.

PubMed

Ko, Li-Wei; Komarov, Oleksii; Hairston, W David; Jung, Tzyy-Ping; Lin, Chin-Teng

2017-01-01

Sustained attention is a process that enables the maintenance of response persistence and continuous effort over extended periods of time. Performing attention-related tasks in real life involves the need to ignore a variety of distractions and inhibit attention shifts to irrelevant activities. This study investigates electroencephalography (EEG) spectral changes during a sustained attention task within a real classroom environment. Eighteen healthy students were instructed to recognize as fast as possible special visual targets that were displayed during regular university lectures. Sorting their EEG spectra with respect to response times, which indicated the level of visual alertness to randomly introduced visual stimuli, revealed significant changes in the brain oscillation patterns. The results of power-frequency analysis demonstrated a relationship between variations in the EEG spectral dynamics and impaired performance in the sustained attention task. Across subjects and sessions, prolongation of the response time was preceded by an increase in the delta and theta EEG powers over the occipital region, and decrease in the beta power over the occipital and temporal regions. Meanwhile, implementation of the complex attention task paradigm into a real-world classroom setting makes it possible to investigate specific mutual links between brain activities and factors that cause impaired behavioral performance, such as development and manifestation of classroom mental fatigue. The findings of the study set a basis for developing a system capable of estimating the level of visual attention during real classroom activities by monitoring changes in the EEG spectra.

Sustained Attention in Real Classroom Settings: An EEG Study

PubMed Central

Ko, Li-Wei; Komarov, Oleksii; Hairston, W. David; Jung, Tzyy-Ping; Lin, Chin-Teng

2017-01-01

Sustained attention is a process that enables the maintenance of response persistence and continuous effort over extended periods of time. Performing attention-related tasks in real life involves the need to ignore a variety of distractions and inhibit attention shifts to irrelevant activities. This study investigates electroencephalography (EEG) spectral changes during a sustained attention task within a real classroom environment. Eighteen healthy students were instructed to recognize as fast as possible special visual targets that were displayed during regular university lectures. Sorting their EEG spectra with respect to response times, which indicated the level of visual alertness to randomly introduced visual stimuli, revealed significant changes in the brain oscillation patterns. The results of power-frequency analysis demonstrated a relationship between variations in the EEG spectral dynamics and impaired performance in the sustained attention task. Across subjects and sessions, prolongation of the response time was preceded by an increase in the delta and theta EEG powers over the occipital region, and decrease in the beta power over the occipital and temporal regions. Meanwhile, implementation of the complex attention task paradigm into a real-world classroom setting makes it possible to investigate specific mutual links between brain activities and factors that cause impaired behavioral performance, such as development and manifestation of classroom mental fatigue. The findings of the study set a basis for developing a system capable of estimating the level of visual attention during real classroom activities by monitoring changes in the EEG spectra. PMID:28824396

Human experimental anxiety: actual public speaking induces more intense physiological responses than simulated public speaking.

PubMed

Zuardi, Antonio Waldo; Crippa, José Alexandre de Souza; Hallak, Jaime Eduardo Cecílio; Gorayeb, Ricardo

2013-01-01

a) To perform a systematic and meta-analytic review to verify whether the Simulated Public Speaking Task (SPST) leads to a greater increase in self-rated anxiety than in physiological correlates of anxiety; and b) to compare the results obtained with the SPST with an actual public speaking task involving healthy volunteers. a) The PubMed and ISI Web of Knowledge databases were searched for studies involving the SPST prior to 2012. Eleven publications were eligible and provided data from 143 healthy volunteers for meta-analysis; b) 48 university students without somatic or psychiatric disorders were divided into three experimental groups of 16 subjects to undergo one of the following: SPST, real-world public speaking task (real-world), and control situation (control). The meta-analysis showed that the SPST induced a significant increase in the Visual Analogue Mood Scale (VAMS) anxiety factor, but no significant increases in systolic blood pressure or heart rate. The empirical study showed that the real-world public speaking task increased heart rate, systolic blood pressure and diastolic blood pressure significantly more than the control and SPST conditions. These results suggest that real public speaking might be better than SPST in inducing experimental anxiety.

A virtual shopping task for the assessment of executive functions: Validity for people with stroke.

PubMed

Nir-Hadad, Shira Yama; Weiss, Patrice L; Waizman, Anna; Schwartz, Natalia; Kizony, Rachel

2017-07-01

The importance of assessing executive functions (EF) using ecologically valid assessments has been discussed extensively. Due to the difficulty of carrying out such assessments in real-world settings on a regular basis, virtual reality has been proposed as a technique to provide complex functional tasks under a variety of differing conditions while measuring various aspects of performance and controlling for stimuli. The main goal of this study was to examine the discriminant, construct-convergent and ecological validity of the Adapted Four-Item Shopping Task, an assessment of the Instrumental Activity of Daily Living (IADL) of shopping. Nineteen people with stroke, aged 50-85 years, and 20 age- and gender-matched healthy participants performed the shopping task in both the SeeMe Virtual Interactive Shopping environment and a real shopping environment (the hospital cafeteria) in a counterbalanced order. The shopping task outcomes were compared to clinical measures of EF. The findings provided good initial support for the validity of the Adapted Four-Item Shopping Task as an IADL assessment that requires the use of EF for people with stroke. Further studies should examine this task with a larger sample of people with stroke as well as with other populations who have deficits in EF.

Evidence-Based Occupational Hearing Screening I: Modeling the Effects of Real-World Noise Environments on the Likelihood of Effective Speech Communication.

PubMed

Soli, Sigfrid D; Giguère, Christian; Laroche, Chantal; Vaillancourt, Véronique; Dreschler, Wouter A; Rhebergen, Koenraad S; Harkins, Kevin; Ruckstuhl, Mark; Ramulu, Pradeep; Meyers, Lawrence S

The objectives of this study were to (1) identify essential hearing-critical job tasks for public safety and law enforcement personnel; (2) determine the locations and real-world noise environments where these tasks are performed; (3) characterize each noise environment in terms of its impact on the likelihood of effective speech communication, considering the effects of different levels of vocal effort, communication distances, and repetition; and (4) use this characterization to define an objective normative reference for evaluating the ability of individuals to perform essential hearing-critical job tasks in noisy real-world environments. Data from five occupational hearing studies performed over a 17-year period for various public safety agencies were analyzed. In each study, job task analyses by job content experts identified essential hearing-critical tasks and the real-world noise environments where these tasks are performed. These environments were visited, and calibrated recordings of each noise environment were made. The extended speech intelligibility index (ESII) was calculated for each 4-sec interval in each recording. These data, together with the estimated ESII value required for effective speech communication by individuals with normal hearing, allowed the likelihood of effective speech communication in each noise environment for different levels of vocal effort and communication distances to be determined. These likelihoods provide an objective norm-referenced and standardized means of characterizing the predicted impact of real-world noise on the ability to perform essential hearing-critical tasks. A total of 16 noise environments for law enforcement personnel and eight noise environments for corrections personnel were analyzed. Effective speech communication was essential to hearing-critical tasks performed in these environments. Average noise levels, ranged from approximately 70 to 87 dBA in law enforcement environments and 64 to 80 dBA in corrections environments. The likelihood of effective speech communication at communication distances of 0.5 and 1 m was often less than 0.50 for normal vocal effort. Likelihood values often increased to 0.80 or more when raised or loud vocal effort was used. Effective speech communication at and beyond 5 m was often unlikely, regardless of vocal effort. ESII modeling of nonstationary real-world noise environments may prove an objective means of characterizing their impact on the likelihood of effective speech communication. The normative reference provided by these measures predicts the extent to which hearing impairments that increase the ESII value required for effective speech communication also decrease the likelihood of effective speech communication. These predictions may provide an objective evidence-based link between the essential hearing-critical job task requirements of public safety and law enforcement personnel and ESII-based hearing assessment of individuals who seek to perform these jobs.

Rumors of transcendence in physics

NASA Astrophysics Data System (ADS)

Pollard, William G.

1984-10-01

There are several hints in physics of a domain of external reality transcendent to three-dimensional space and time. This paper calls attention to several of these intimations of a real world beyond the natural order. Examples are the complex state functions in configuration space of quantum mechanics, the singularity at the birth of the universe, the anthropic principle, the role of chance in evolution, and the unaccountable fruitfulness of mathematics for physics. None of these examples touch on the existence or activity of God, but they do suggest that external reality may be much richer than the natural world which it is the task of physics to describe.

Task directed sensing

NASA Technical Reports Server (NTRS)

Firby, R. James

1990-01-01

High-level robot control research must confront the limitations imposed by real sensors if robots are to be controlled effectively in the real world. In particular, sensor limitations make it impossible to maintain a complete, detailed world model of the situation surrounding the robot. To address the problems involved in planning with the resulting incomplete and uncertain world models, traditional robot control architectures must be altered significantly. Task-directed sensing and control is suggested as a way of coping with world model limitations by focusing sensing and analysis resources on only those parts of the world relevant to the robot's active goals. The RAP adaptive execution system is used as an example of a control architecture designed to deploy sensing resources in this way to accomplish both action and knowledge goals.

High-performance execution of psychophysical tasks with complex visual stimuli in MATLAB

PubMed Central

Asaad, Wael F.; Santhanam, Navaneethan; McClellan, Steven

2013-01-01

Behavioral, psychological, and physiological experiments often require the ability to present sensory stimuli, monitor and record subjects' responses, interface with a wide range of devices, and precisely control the timing of events within a behavioral task. Here, we describe our recent progress developing an accessible and full-featured software system for controlling such studies using the MATLAB environment. Compared with earlier reports on this software, key new features have been implemented to allow the presentation of more complex visual stimuli, increase temporal precision, and enhance user interaction. These features greatly improve the performance of the system and broaden its applicability to a wider range of possible experiments. This report describes these new features and improvements, current limitations, and quantifies the performance of the system in a real-world experimental setting. PMID:23034363

Impaired behavior on real-world tasks following damage to the ventromedial prefrontal cortex.

PubMed

Tranel, Daniel; Hathaway-Nepple, Julie; Anderson, Steven W

2007-04-01

Patients with damage to the ventromedial prefrontal cortices (VMPC) commonly manifest blatant behavioral navigation defects in the real world, but it has been difficult to measure these impairments in the clinic or laboratory. Using a set of "strategy application" tasks, which were designed by Shallice and Burgess (1991) to be ecologically valid for detecting executive dysfunction, we investigated the hypothesis that VMPC damage would be associated with defective performance on such tasks, whereas damage outside the VMPC region would not. A group of 9 patients with bilateral VMPC damage was contrasted with comparison groups of participants with (a) prefrontal brain damage outside the VMPC region (n = 8); (b) nonprefrontal brain damage (n = 17); and (c) no brain damage (n = 20). We found support for the hypothesis: VMPC patients had more impaired performances on the strategy application tasks, especially on a Multiple Errands Test that required patients to execute a series of unstructured tasks in a real-world setting (shopping mall). The results are consistent with the notion that efficacious behavioral navigation is dependent on the VMPC region. However, the strategy application tasks were relatively time consuming and effortful, and their diagnostic yield over and above conventional executive functioning tests may not be sufficient to warrant their inclusion in standard clinical assessment.

Impaired behavior on real-world tasks following damage to the ventromedial prefrontal cortex

PubMed Central

Tranel, Daniel; Hathaway-Nepple, Julie; Anderson, Steven W.

2008-01-01

Patients with damage to the ventromedial prefrontal cortices (VMPC) commonly manifest blatant behavioral navigation defects in the real world, but it has been difficult to measure these impairments in the clinic or laboratory. Using a set of “strategy application” tasks, which were designed by Shallice and Burgess (1991) to be ecologically valid for detecting executive dysfunction, we investigated the hypothesis that VMPC damage would be associated with defective performance on such tasks, whereas damage outside the VMPC region would not. A group of 9 patients with bilateral VMPC damage was contrasted with comparison groups of participants with (a) prefrontal brain damage outside the VMPC region (n=8); (b) nonprefrontal brain damage (n=17); and (c) no brain damage (n=20). We found support for the hypothesis: VMPC patients had more impaired performances on the strategy application tasks, especially on a Multiple Errands Test that required patients to execute a series of unstructured tasks in a real-world setting (shopping mall). The results are consistent with the notion that efficacious behavioral navigation is dependent on the VMPC region. However, the strategy application tasks were relatively time consuming and effortful, and their diagnostic yield over and above conventional executive functioning tests may not be sufficient to warrant their inclusion in standard clinical assessment. PMID:17454352

Perceived orientation in physical and virtual environments: changes in perceived orientation as a function of idiothetic information available

NASA Technical Reports Server (NTRS)

Lathrop, William B.; Kaiser, Mary K.

2002-01-01

Two experiments examined perceived spatial orientation in a small environment as a function of experiencing that environment under three conditions: real-world, desktop-display (DD), and head-mounted display (HMD). Across the three conditions, participants acquired two targets located on a perimeter surrounding them, and attempted to remember the relative locations of the targets. Subsequently, participants were tested on how accurately and consistently they could point in the remembered direction of a previously seen target. Results showed that participants were significantly more consistent in the real-world and HMD conditions than in the DD condition. Further, it is shown that the advantages observed in the HMD and real-world conditions were not simply due to nonspatial response strategies. These results suggest that the additional idiothetic information afforded in the real-world and HMD conditions is useful for orientation purposes in our presented task domain. Our results are relevant to interface design issues concerning tasks that require spatial search, navigation, and visualization.

Vision-Based Real-Time Traversable Region Detection for Mobile Robot in the Outdoors.

PubMed

Deng, Fucheng; Zhu, Xiaorui; He, Chao

2017-09-13

Environment perception is essential for autonomous mobile robots in human-robot coexisting outdoor environments. One of the important tasks for such intelligent robots is to autonomously detect the traversable region in an unstructured 3D real world. The main drawback of most existing methods is that of high computational complexity. Hence, this paper proposes a binocular vision-based, real-time solution for detecting traversable region in the outdoors. In the proposed method, an appearance model based on multivariate Gaussian is quickly constructed from a sample region in the left image adaptively determined by the vanishing point and dominant borders. Then, a fast, self-supervised segmentation scheme is proposed to classify the traversable and non-traversable regions. The proposed method is evaluated on public datasets as well as a real mobile robot. Implementation on the mobile robot has shown its ability in the real-time navigation applications.

Development and validation of a virtual reality simulator: human factors input to interventional radiology training.

PubMed

Johnson, Sheena Joanne; Guediri, Sara M; Kilkenny, Caroline; Clough, Peter J

2011-12-01

This study developed and validated a virtual reality (VR) simulator for use by interventional radiologists. Research in the area of skill acquisition reports practice as essential to become a task expert. Studies on simulation show skills learned in VR can be successfully transferred to a real-world task. Recently, with improvements in technology, VR simulators have been developed to allow complex medical procedures to be practiced without risking the patient. Three studies are reported. In Study I, 35 consultant interventional radiologists took part in a cognitive task analysis to empirically establish the key competencies of the Seldinger procedure. In Study 2, 62 participants performed one simulated procedure, and their performance was compared by expertise. In Study 3, the transferability of simulator training to a real-world procedure was assessed with 14 trainees. Study I produced 23 key competencies that were implemented as performance measures in the simulator. Study 2 showed the simulator had both face and construct validity, although some issues were identified. Study 3 showed the group that had undergone simulator training received significantly higher mean performance ratings on a subsequent patient procedure. The findings of this study support the centrality of validation in the successful design of simulators and show the utility of simulators as a training device. The studies show the key elements of a validation program for a simulator. In addition to task analysis and face and construct validities, the authors highlight the importance of transfer of training in validation studies.

Demand curves for hypothetical cocaine in cocaine-dependent individuals.

PubMed

Bruner, Natalie R; Johnson, Matthew W

2014-03-01

Drug purchasing tasks have been successfully used to examine demand for hypothetical consumption of abused drugs including heroin, nicotine, and alcohol. In these tasks, drug users make hypothetical choices whether to buy drugs, and if so, at what quantity, at various potential prices. These tasks allow for behavioral economic assessment of that drug's intensity of demand (preferred level of consumption at extremely low prices) and demand elasticity (sensitivity of consumption to price), among other metrics. However, a purchasing task for cocaine in cocaine-dependent individuals has not been investigated. This study examined a novel Cocaine Purchasing Task and the relation between resulting demand metrics and self-reported cocaine use data. Participants completed a questionnaire assessing hypothetical purchases of cocaine units at prices ranging from $0.01 to $1,000. Demand curves were generated from responses on the Cocaine Purchasing Task. Correlations compared metrics from the demand curve to measures of real-world cocaine use. Group and individual data were well modeled by a demand curve function. The validity of the Cocaine Purchasing Task was supported by a significant correlation between the demand curve metrics of demand intensity and O max (determined from Cocaine Purchasing Task data) and self-reported measures of cocaine use. Partial correlations revealed that after controlling for demand intensity, demand elasticity and the related measure, P max, were significantly correlated with real-world cocaine use. Results indicate that the Cocaine Purchasing Task produces orderly demand curve data, and that these data relate to real-world measures of cocaine use.

Evaluation of Teaching Signals for Motor Control in the Cerebellum during Real-World Robot Application.

PubMed

Pinzon Morales, Ruben Dario; Hirata, Yutaka

2016-12-20

Motor learning in the cerebellum is believed to entail plastic changes at synapses between parallel fibers and Purkinje cells, induced by the teaching signal conveyed in the climbing fiber (CF) input. Despite the abundant research on the cerebellum, the nature of this signal is still a matter of debate. Two types of movement error information have been proposed to be plausible teaching signals: sensory error (SE) and motor command error (ME); however, their plausibility has not been tested in the real world. Here, we conducted a comparison of different types of CF teaching signals in real-world engineering applications by using a realistic neuronal network model of the cerebellum. We employed a direct current motor (simple task) and a two-wheeled balancing robot (difficult task). We demonstrate that SE, ME or a linear combination of the two is sufficient to yield comparable performance in a simple task. When the task is more difficult, although SE slightly outperformed ME, these types of error information are all able to adequately control the robot. We categorize granular cells according to their inputs and the error signal revealing that different granule cells are preferably engaged for SE, ME or their combination. Thus, unlike previous theoretical and simulation studies that support either SE or ME, it is demonstrated for the first time in a real-world engineering application that both SE and ME are adequate as the CF teaching signal in a realistic computational cerebellar model, even when the control task is as difficult as stabilizing a two-wheeled balancing robot.

Evaluation of Teaching Signals for Motor Control in the Cerebellum during Real-World Robot Application

PubMed Central

Pinzon Morales, Ruben Dario; Hirata, Yutaka

2016-01-01

Motor learning in the cerebellum is believed to entail plastic changes at synapses between parallel fibers and Purkinje cells, induced by the teaching signal conveyed in the climbing fiber (CF) input. Despite the abundant research on the cerebellum, the nature of this signal is still a matter of debate. Two types of movement error information have been proposed to be plausible teaching signals: sensory error (SE) and motor command error (ME); however, their plausibility has not been tested in the real world. Here, we conducted a comparison of different types of CF teaching signals in real-world engineering applications by using a realistic neuronal network model of the cerebellum. We employed a direct current motor (simple task) and a two-wheeled balancing robot (difficult task). We demonstrate that SE, ME or a linear combination of the two is sufficient to yield comparable performance in a simple task. When the task is more difficult, although SE slightly outperformed ME, these types of error information are all able to adequately control the robot. We categorize granular cells according to their inputs and the error signal revealing that different granule cells are preferably engaged for SE, ME or their combination. Thus, unlike previous theoretical and simulation studies that support either SE or ME, it is demonstrated for the first time in a real-world engineering application that both SE and ME are adequate as the CF teaching signal in a realistic computational cerebellar model, even when the control task is as difficult as stabilizing a two-wheeled balancing robot. PMID:27999381

Development of a Paradigm to Assess Nutritive and Biochemical Substances in Humans: A Preliminary Report on the Effects of Tyrosine upon Altitude- and Cold-Induced Stress Responses

DTIC Science & Technology

1987-03-01

3/4 hours. Performance tests evaluated simple and choice reaction time to visual stimuli, vigilance, and processing of symbolic, numerical, verbal...minimize the adverse consequences of these stressors. Tyrosine enhanced performance (e.g. complex information processing , vigilance, and reaction time... processes inherent in many real-world tasks. For example, Map Compass requires association of Wsi PL AFCm uA O-SV CHETCLtISS) direction and degree

United Space Alliance LLC Parachute Refurbishment Facility Model

NASA Technical Reports Server (NTRS)

Esser, Valerie; Pessaro, Martha; Young, Angela

2007-01-01

The Parachute Refurbishment Facility Model was created to reflect the flow of hardware through the facility using anticipated start and delivery times from a project level IV schedule. Distributions for task times were built using historical build data for SFOC work and new data generated for CLV/ARES task times. The model currently processes 633 line items from 14 SFOC builds for flight readiness, 16 SFOC builds returning from flight for defoul, wash, and dry operations, 12 builds for CLV manufacturing operations, and 1 ARES 1X build. Modeling the planned workflow through the PRF is providing a reliable way to predict the capability of the facility as well as the manpower resource need. Creating a real world process allows for real world problems to be identified and potential workarounds to be implemented in a safe, simulated world before taking it to the next step, implementation in the real world.

Popularity and Novelty Dynamics in Evolving Networks.

PubMed

Abbas, Khushnood; Shang, Mingsheng; Abbasi, Alireza; Luo, Xin; Xu, Jian Jun; Zhang, Yu-Xia

2018-04-20

Network science plays a big role in the representation of real-world phenomena such as user-item bipartite networks presented in e-commerce or social media platforms. It provides researchers with tools and techniques to solve complex real-world problems. Identifying and predicting future popularity and importance of items in e-commerce or social media platform is a challenging task. Some items gain popularity repeatedly over time while some become popular and novel only once. This work aims to identify the key-factors: popularity and novelty. To do so, we consider two types of novelty predictions: items appearing in the popular ranking list for the first time; and items which were not in the popular list in the past time window, but might have been popular before the recent past time window. In order to identify the popular items, a careful consideration of macro-level analysis is needed. In this work we propose a model, which exploits item level information over a span of time to rank the importance of the item. We considered ageing or decay effect along with the recent link-gain of the items. We test our proposed model on four various real-world datasets using four information retrieval based metrics.

Transcranial direct current stimulation facilitates cognitive multi-task performance differentially depending on anode location and subtask

PubMed Central

Scheldrup, Melissa; Greenwood, Pamela M.; McKendrick, Ryan; Strohl, Jon; Bikson, Marom; Alam, Mahtab; McKinley, R. Andy; Parasuraman, Raja

2014-01-01

There is a need to facilitate acquisition of real world cognitive multi-tasks that require long periods of training (e.g., air traffic control, intelligence analysis, medicine). Non-invasive brain stimulation—specifically transcranial Direct Current Stimulation (tDCS)—has promise as a method to speed multi-task training. We hypothesized that during acquisition of the complex multi-task Space Fortress, subtasks that require focused attention on ship control would benefit from tDCS aimed at the dorsal attention network while subtasks that require redirection of attention would benefit from tDCS aimed at the right hemisphere ventral attention network. We compared effects of 30 min prefrontal and parietal stimulation to right and left hemispheres on subtask performance during the first 45 min of training. The strongest effects both overall and for ship flying (control and velocity subtasks) were seen with a right parietal (C4, reference to left shoulder) montage, shown by modeling to induce an electric field that includes nodes in both dorsal and ventral attention networks. This is consistent with the re-orienting hypothesis that the ventral attention network is activated along with the dorsal attention network if a new, task-relevant event occurs while visuospatial attention is focused (Corbetta et al., 2008). No effects were seen with anodes over sites that stimulated only dorsal (C3) or only ventral (F10) attention networks. The speed subtask (update memory for symbols) benefited from an F9 anode over left prefrontal cortex. These results argue for development of tDCS as a training aid in real world settings where multi-tasking is critical. PMID:25249958

Transcranial direct current stimulation facilitates cognitive multi-task performance differentially depending on anode location and subtask.

PubMed

Scheldrup, Melissa; Greenwood, Pamela M; McKendrick, Ryan; Strohl, Jon; Bikson, Marom; Alam, Mahtab; McKinley, R Andy; Parasuraman, Raja

2014-01-01

There is a need to facilitate acquisition of real world cognitive multi-tasks that require long periods of training (e.g., air traffic control, intelligence analysis, medicine). Non-invasive brain stimulation-specifically transcranial Direct Current Stimulation (tDCS)-has promise as a method to speed multi-task training. We hypothesized that during acquisition of the complex multi-task Space Fortress, subtasks that require focused attention on ship control would benefit from tDCS aimed at the dorsal attention network while subtasks that require redirection of attention would benefit from tDCS aimed at the right hemisphere ventral attention network. We compared effects of 30 min prefrontal and parietal stimulation to right and left hemispheres on subtask performance during the first 45 min of training. The strongest effects both overall and for ship flying (control and velocity subtasks) were seen with a right parietal (C4, reference to left shoulder) montage, shown by modeling to induce an electric field that includes nodes in both dorsal and ventral attention networks. This is consistent with the re-orienting hypothesis that the ventral attention network is activated along with the dorsal attention network if a new, task-relevant event occurs while visuospatial attention is focused (Corbetta et al., 2008). No effects were seen with anodes over sites that stimulated only dorsal (C3) or only ventral (F10) attention networks. The speed subtask (update memory for symbols) benefited from an F9 anode over left prefrontal cortex. These results argue for development of tDCS as a training aid in real world settings where multi-tasking is critical.

The disruptive effects of pain on multitasking in a virtual errands task.

PubMed

Moore, David J; Law, Anna S

2017-07-01

Pain is known to have a disruptive effect on cognitive performance, but prior studies have used highly constrained laboratory tasks that lack ecological validity. In everyday life people are required to complete more complex sets of tasks, prioritising task completion and recalling lists of tasks which need to be completed, and these tasks continue to be attempted during episodes or states of pain. The present study therefore examined the impact of thermal induced pain on a simulated errand task. Fifty-five healthy adults (36 female) performed the Edinburgh Virtual Errands Task (EVET) either during a painful thermal sensation or with no concurrent pain. Participants also completed the Experience of Cognitive Intrusion of Pain (ECIP) questionnaire to measure their self-reported cognitive impact of pain in general life. Participants who completed the EVET task in pain and who self-reported high intrusion of pain made significantly more errors than those who reported lower intrusion on the ECIP. Findings here support the growing literature that suggests that pain has a significant impact on cognitive performance. Furthermore, these findings support the developing literature suggesting that this relationship is complex when considering real world cognition, and that self-report on the ECIP relates well to performance on a task designed to reflect the complexities of everyday living. If extrapolated to chronic pain populations, these data suggest that pain during complex multitasking performance may have a significant impact on the number of errors made. For people highly vulnerable to cognitive intrusion by pain, this may result in errors such as selecting the wrong location or item to perform tasks, or forgetting to perform these tasks at the correct time. If these findings are shown to extend to chronic pain populations then occupational support to manage complex task performance, using for example diaries/electronic reminders, may help to improve everyday abilities. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Beyond the real world: attention debates in auditory mismatch negativity.

PubMed

Chung, Kyungmi; Park, Jin Young

2018-04-11

The aim of this study was to address the potential for the auditory mismatch negativity (aMMN) to be used in applied event-related potential (ERP) studies by determining whether the aMMN would be an attention-dependent ERP component and could be differently modulated across visual tasks or virtual reality (VR) stimuli with different visual properties and visual complexity levels. A total of 80 participants, aged 19-36 years, were assigned to either a reading-task (21 men and 19 women) or a VR-task (22 men and 18 women) group. Two visual-task groups of healthy young adults were matched in age, sex, and handedness. All participants were instructed to focus only on the given visual tasks and ignore auditory change detection. While participants in the reading-task group read text slides, those in the VR-task group viewed three 360° VR videos in a random order and rated how visually complex the given virtual environment was immediately after each VR video ended. Inconsistent with the finding of a partial significant difference in perceived visual complexity in terms of brightness of virtual environments, both visual properties of distance and brightness showed no significant differences in the modulation of aMMN amplitudes. A further analysis was carried out to compare elicited aMMN amplitudes of a typical MMN task and an applied VR task. No significant difference in the aMMN amplitudes was found across the two groups who completed visual tasks with different visual-task demands. In conclusion, the aMMN is a reliable ERP marker of preattentive cognitive processing for auditory deviance detection.

Lightwave: An interactive estimation of indirect illumination using waves of light

NASA Astrophysics Data System (ADS)

Robertson, Michael

With the growth of computers and technology, so to has grown the desire to accurately recreate our world using computer graphics. However, our world is very complex and in many ways beyond our comprehension. Therefore, in order to perform this task, we must consider multiple disciplines and areas of research including physics, mathematics, optics, geology, and many more to at the very least approximate the world around us. The applications of being able to do this are plentiful as well, including the use of graphics in entertainment such as movies and games, in science such as weather forecasts and simulations, in medicine with body scans, or used in architecture, design, and many other areas. In order to recreate the world around us, an important task is to accurately recreate the way light travels and affects the objects we see. Rendering lighting has been a heavily researched area since the 1970's and has gotten more sophisticated over the years. Until recent developments in technology, realistic lighting of scenes has only been achievable offline taking seconds to hours or more to create a single image, however, due to advances in graphics technology, realistic lighting can be done in real-time. An important aspect of realistic lighting involves the inclusion of indirect illumination. However, to achieve a real-time rendering with indirect illumination, we must make trade-offs between scientific accuracy and performance, but as will be discussed later, scientific accuracy may not be necessary after all.

Non-linear molecular pattern classification using molecular beacons with multiple targets.

PubMed

Lee, In-Hee; Lee, Seung Hwan; Park, Tai Hyun; Zhang, Byoung-Tak

2013-12-01

In vitro pattern classification has been highlighted as an important future application of DNA computing. Previous work has demonstrated the feasibility of linear classifiers using DNA-based molecular computing. However, complex tasks require non-linear classification capability. Here we design a molecular beacon that can interact with multiple targets and experimentally shows that its fluorescent signals form a complex radial-basis function, enabling it to be used as a building block for non-linear molecular classification in vitro. The proposed method was successfully applied to solving artificial and real-world classification problems: XOR and microRNA expression patterns. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Adaptive robotic control driven by a versatile spiking cerebellar network.

PubMed

Casellato, Claudia; Antonietti, Alberto; Garrido, Jesus A; Carrillo, Richard R; Luque, Niceto R; Ros, Eduardo; Pedrocchi, Alessandra; D'Angelo, Egidio

2014-01-01

The cerebellum is involved in a large number of different neural processes, especially in associative learning and in fine motor control. To develop a comprehensive theory of sensorimotor learning and control, it is crucial to determine the neural basis of coding and plasticity embedded into the cerebellar neural circuit and how they are translated into behavioral outcomes in learning paradigms. Learning has to be inferred from the interaction of an embodied system with its real environment, and the same cerebellar principles derived from cell physiology have to be able to drive a variety of tasks of different nature, calling for complex timing and movement patterns. We have coupled a realistic cerebellar spiking neural network (SNN) with a real robot and challenged it in multiple diverse sensorimotor tasks. Encoding and decoding strategies based on neuronal firing rates were applied. Adaptive motor control protocols with acquisition and extinction phases have been designed and tested, including an associative Pavlovian task (Eye blinking classical conditioning), a vestibulo-ocular task and a perturbed arm reaching task operating in closed-loop. The SNN processed in real-time mossy fiber inputs as arbitrary contextual signals, irrespective of whether they conveyed a tone, a vestibular stimulus or the position of a limb. A bidirectional long-term plasticity rule implemented at parallel fibers-Purkinje cell synapses modulated the output activity in the deep cerebellar nuclei. In all tasks, the neurorobot learned to adjust timing and gain of the motor responses by tuning its output discharge. It succeeded in reproducing how human biological systems acquire, extinguish and express knowledge of a noisy and changing world. By varying stimuli and perturbations patterns, real-time control robustness and generalizability were validated. The implicit spiking dynamics of the cerebellar model fulfill timing, prediction and learning functions.

Data Literacy: Real-World Learning through Problem-Solving with Data Sets

ERIC Educational Resources Information Center

Erwin, Robin W., Jr.

2015-01-01

The achievement of deep learning by secondary students requires teaching approaches that draw students into task commitment, integrated curricula, and analytical thinking. By using real-world data sets in project based instructional units, teachers can guide students in analyzing, interpreting, and reporting quantitative data. Working with…

Lessons Learned from Crowdsourcing Complex Engineering Tasks

PubMed Central

Kijewski-Correa, Tracy; Thain, Douglas; Kareem, Ahsan; Madey, Gregory

2015-01-01

Crowdsourcing Crowdsourcing is the practice of obtaining needed ideas, services, or content by requesting contributions from a large group of people. Amazon Mechanical Turk is a web marketplace for crowdsourcing microtasks, such as answering surveys and image tagging. We explored the limits of crowdsourcing by using Mechanical Turk for a more complicated task: analysis and creation of wind simulations. Harnessing Crowdworkers for Engineering Our investigation examined the feasibility of using crowdsourcing for complex, highly technical tasks. This was done to determine if the benefits of crowdsourcing could be harnessed to accurately and effectively contribute to solving complex real world engineering problems. Of course, untrained crowds cannot be used as a mere substitute for trained expertise. Rather, we sought to understand how crowd workers can be used as a large pool of labor for a preliminary analysis of complex data. Virtual Wind Tunnel We compared the skill of the anonymous crowd workers from Amazon Mechanical Turk with that of civil engineering graduate students, making a first pass at analyzing wind simulation data. For the first phase, we posted analysis questions to Amazon crowd workers and to two groups of civil engineering graduate students. A second phase of our experiment instructed crowd workers and students to create simulations on our Virtual Wind Tunnel website to solve a more complex task. Conclusions With a sufficiently comprehensive tutorial and compensation similar to typical crowd-sourcing wages, we were able to enlist crowd workers to effectively complete longer, more complex tasks with competence comparable to that of graduate students with more comprehensive, expert-level knowledge. Furthermore, more complex tasks require increased communication with the workers. As tasks become more complex, the employment relationship begins to become more akin to outsourcing than crowdsourcing. Through this investigation, we were able to stretch and explore the limits of crowdsourcing as a tool for solving complex problems. PMID:26383029

Levels of Information Processing in a Fitts law task (LIPFitts)

NASA Technical Reports Server (NTRS)

Mosier, K. L.; Hart, S. G.

1986-01-01

State-of-the-art flight technology has restructured the task of human operators, decreasing the need for physical and sensory resources, and increasing the quantity of cognitive effort required, changing it qualitatively. Recent technological advances have the most potential for impacting a pilot in two areas: performance and mental workload. In an environment in which timing is critical, additional cognitive processing can cause performance decrements, and increase a pilot's perception of the mental workload involved. The effects of stimulus processing demands on motor response performance and subjective mental workload are examined, using different combinations of response selection and target acquisition tasks. The information processing demands of the response selection were varied (e.g., Sternberg memory set tasks, math equations, pattern matching), as was the difficulty of the response execution. Response latency as well as subjective workload ratings varied in accordance with the cognitive complexity of the task. Movement times varied according to the difficulty of the response execution task. Implications in terms of real-world flight situations are discussed.

Threaded cognition: an integrated theory of concurrent multitasking.

PubMed

Salvucci, Dario D; Taatgen, Niels A

2008-01-01

The authors propose the idea of threaded cognition, an integrated theory of concurrent multitasking--that is, performing 2 or more tasks at once. Threaded cognition posits that streams of thought can be represented as threads of processing coordinated by a serial procedural resource and executed across other available resources (e.g., perceptual and motor resources). The theory specifies a parsimonious mechanism that allows for concurrent execution, resource acquisition, and resolution of resource conflicts, without the need for specialized executive processes. By instantiating this mechanism as a computational model, threaded cognition provides explicit predictions of how multitasking behavior can result in interference, or lack thereof, for a given set of tasks. The authors illustrate the theory in model simulations of several representative domains ranging from simple laboratory tasks such as dual-choice tasks to complex real-world domains such as driving and driver distraction. (c) 2008 APA, all rights reserved

Children's sequential information search is sensitive to environmental probabilities.

PubMed

Nelson, Jonathan D; Divjak, Bojana; Gudmundsdottir, Gudny; Martignon, Laura F; Meder, Björn

2014-01-01

We investigated 4th-grade children's search strategies on sequential search tasks in which the goal is to identify an unknown target object by asking yes-no questions about its features. We used exhaustive search to identify the most efficient question strategies and evaluated the usefulness of children's questions accordingly. Results show that children have good intuitions regarding questions' usefulness and search adaptively, relative to the statistical structure of the task environment. Search was especially efficient in a task environment that was representative of real-world experiences. This suggests that children may use their knowledge of real-world environmental statistics to guide their search behavior. We also compared different related search tasks. We found positive transfer effects from first doing a number search task on a later person search task. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Searching for unity: Real-world versus item-based visual search in age-related eye disease.

PubMed

Crabb, David P; Taylor, Deanna J

2017-01-01

When studying visual search, item-based approaches using synthetic targets and distractors limit the real-world applicability of results. Everyday visual search can be impaired in patients with common eye diseases like glaucoma and age-related macular degeneration. We highlight some results in the literature that suggest assessment of real-word search tasks in these patients could be clinically useful.

Distributed Cooperation Solution Method of Complex System Based on MAS

NASA Astrophysics Data System (ADS)

Weijin, Jiang; Yuhui, Xu

To adapt the model in reconfiguring fault diagnosing to dynamic environment and the needs of solving the tasks of complex system fully, the paper introduced multi-Agent and related technology to the complicated fault diagnosis, an integrated intelligent control system is studied in this paper. Based on the thought of the structure of diagnostic decision and hierarchy in modeling, based on multi-layer decomposition strategy of diagnosis task, a multi-agent synchronous diagnosis federation integrated different knowledge expression modes and inference mechanisms are presented, the functions of management agent, diagnosis agent and decision agent are analyzed, the organization and evolution of agents in the system are proposed, and the corresponding conflict resolution algorithm in given, Layered structure of abstract agent with public attributes is build. System architecture is realized based on MAS distributed layered blackboard. The real world application shows that the proposed control structure successfully solves the fault diagnose problem of the complex plant, and the special advantage in the distributed domain.

How to use MPI communication in highly parallel climate simulations more easily and more efficiently.

NASA Astrophysics Data System (ADS)

Behrens, Jörg; Hanke, Moritz; Jahns, Thomas

2014-05-01

In this talk we present a way to facilitate efficient use of MPI communication for developers of climate models. Exploitation of the performance potential of today's highly parallel supercomputers with real world simulations is a complex task. This is partly caused by the low level nature of the MPI communication library which is the dominant communication tool at least for inter-node communication. In order to manage the complexity of the task, climate simulations with non-trivial communication patterns often use an internal abstraction layer above MPI without exploiting the benefits of communication aggregation or MPI-datatypes. The solution for the complexity and performance problem we propose is the communication library YAXT. This library is built on top of MPI and takes high level descriptions of arbitrary domain decompositions and automatically derives an efficient collective data exchange. Several exchanges can be aggregated in order to reduce latency costs. Examples are given which demonstrate the simplicity and the performance gains for selected climate applications.

Demand Curves for Hypothetical Cocaine in Cocaine-Dependent Individuals

PubMed Central

Bruner, Natalie R.; Johnson, Matthew W.

2013-01-01

Rationale Drug purchasing tasks have been successfully used to examine demand for hypothetical consumption of abused drugs including heroin, nicotine, and alcohol. In these tasks drug users make hypothetical choices whether to buy drugs, and if so, at what quantity, at various potential prices. These tasks allow for behavioral economic assessment of that drug's intensity of demand (preferred level of consumption at extremely low prices) and demand elasticity (sensitivity of consumption to price), among other metrics. However, a purchasing task for cocaine in cocaine-dependent individuals has not been investigated. Objectives This study examined a novel Cocaine Purchasing Task and the relation between resulting demand metrics and self-reported cocaine use data. Methods Participants completed a questionnaire assessing hypothetical purchases of cocaine units at prices ranging from $0.01 to $1,000. Demand curves were generated from responses on the Cocaine Purchasing Task. Correlations compared metrics from the demand curve to measures of real-world cocaine use. Results Group and individual data were well modeled by a demand curve function. The validity of the Cocaine Purchasing Task was supported by a significant correlation between the demand curve metrics of demand intensity and Omax (determined from Cocaine Purchasing Task data) and self-reported measures of cocaine use. Partial correlations revealed that after controlling for demand intensity, demand elasticity and the related measure, Pmax, were significantly correlated with real-world cocaine use. Conclusions Results indicate that the Cocaine Purchasing Task produces orderly demand curve data, and that these data relate to real-world measures of cocaine use. PMID:24217899

Tuning Out the World with Noise-Canceling Headphones

ERIC Educational Resources Information Center

McCulloch, Allison W.; Whitehead, Ashley; Lovett, Jennifer N.; Whitley, Blake

2017-01-01

Context is what makes mathematical modeling tasks different from more traditional textbook word problems. Math problems are sometimes stripped of context as they are worked on. For modeling problems, however, context is important for making sense of the mathematics. The task should be brought back to its real-world context as often as possible. In…

Neural Codes for One's Own Position and Direction in a Real-World "Vista" Environment.

PubMed

Sulpizio, Valentina; Boccia, Maddalena; Guariglia, Cecilia; Galati, Gaspare

2018-01-01

Humans, like animals, rely on an accurate knowledge of one's spatial position and facing direction to keep orientated in the surrounding space. Although previous neuroimaging studies demonstrated that scene-selective regions (the parahippocampal place area or PPA, the occipital place area or OPA and the retrosplenial complex or RSC), and the hippocampus (HC) are implicated in coding position and facing direction within small-(room-sized) and large-scale navigational environments, little is known about how these regions represent these spatial quantities in a large open-field environment. Here, we used functional magnetic resonance imaging (fMRI) in humans to explore the neural codes of these navigationally-relevant information while participants viewed images which varied for position and facing direction within a familiar, real-world circular square. We observed neural adaptation for repeated directions in the HC, even if no navigational task was required. Further, we found that the amount of knowledge of the environment interacts with the PPA selectivity in encoding positions: individuals who needed more time to memorize positions in the square during a preliminary training task showed less neural attenuation in this scene-selective region. We also observed adaptation effects, which reflect the real distances between consecutive positions, in scene-selective regions but not in the HC. When examining the multi-voxel patterns of activity we observed that scene-responsive regions and the HC encoded both spatial information and that the RSC classification accuracy for positions was higher in individuals scoring higher to a self-reported questionnaire of spatial abilities. Our findings provide new insight into how the human brain represents a real, large-scale "vista" space, demonstrating the presence of neural codes for position and direction in both scene-selective and hippocampal regions, and revealing the existence, in the former regions, of a map-like spatial representation reflecting real-world distance between consecutive positions.

On the break down of reality at superluminal velocities, Quantum entanglement and Singularities (Complex Universe)

NASA Astrophysics Data System (ADS)

Estakhr, Ahmad Reza

2017-09-01

In the real world nothing can move faster than the speed of light. But what convinces you that our world is all real? I realized that reality break down at superluminal velocities (By studying the physics of tachyonic neutrinos), Quantum entanglement and Singularities of Black Holes, I realized that infact our world is complex and has two parts, one part of the world is real (the part that nothing can move faster than the speed of light) but the other part of the world is imaginary. z = a + ib Einstein was wrong because he thought our world is completely real (Of course he was not alone in this belief almost all physicists believe that our world is completely real) Eventually his false interpretation of reality censored imaginary part of the universe. Einstein's Second Postulate of special theory of relativity was a misleading guide to the true nature of reality. He `expected' the true nature of reality will follow to his (false) postulate, But the true nature of reality is unlike what anyone ever `expected'!. Einstein twist facts to suit his theory of relativity instead of theories to suit facts!. This is a dramatic revisions to our conception of the theory of relativity, Reality is complex but We always perceive its real part.

21st-Century Urban Renewal: Mathematical Understanding of Real-World Graphical Data Using Geospatial Technologies

ERIC Educational Resources Information Center

DeBay, Dennis J.

2017-01-01

The introduction of real-world, meaningful tasks in mathematics classrooms promises to create opportunities for enhancing students' learning through active engagement with mathematical ideas; however, researchers have given little consideration to the contexts in which urban high-school students live. The case study of three students reported in…

Real-time value-driven diagnosis

NASA Technical Reports Server (NTRS)

Dambrosio, Bruce

1995-01-01

Diagnosis is often thought of as an isolated task in theoretical reasoning (reasoning with the goal of updating our beliefs about the world). We present a decision-theoretic interpretation of diagnosis as a task in practical reasoning (reasoning with the goal of acting in the world), and sketch components of our approach to this task. These components include an abstract problem description, a decision-theoretic model of the basic task, a set of inference methods suitable for evaluating the decision representation in real-time, and a control architecture to provide the needed continuing coordination between the agent and its environment. A principal contribution of this work is the representation and inference methods we have developed, which extend previously available probabilistic inference methods and narrow, somewhat, the gap between probabilistic and logical models of diagnosis.

Food for Thought: Cross-Classification and Category Organization in a Complex Real-World Domain.

ERIC Educational Resources Information Center

Ross, Brian H.; Murphy, Gregory L.

1999-01-01

Seven studies involving 256 undergraduates examined how people represent, access, and make inferences about the real-world category domain, foods. Results give a detailed picture of the use of cross-classification in a complex domain. (SLD)

Evaluation of the cognitive effects of travel technique in complex real and virtual environments.

PubMed

Suma, Evan A; Finkelstein, Samantha L; Reid, Myra; V Babu, Sabarish; Ulinski, Amy C; Hodges, Larry F

2010-01-01

We report a series of experiments conducted to investigate the effects of travel technique on information gathering and cognition in complex virtual environments. In the first experiment, participants completed a non-branching multilevel 3D maze at their own pace using either real walking or one of two virtual travel techniques. In the second experiment, we constructed a real-world maze with branching pathways and modeled an identical virtual environment. Participants explored either the real or virtual maze for a predetermined amount of time using real walking or a virtual travel technique. Our results across experiments suggest that for complex environments requiring a large number of turns, virtual travel is an acceptable substitute for real walking if the goal of the application involves learning or reasoning based on information presented in the virtual world. However, for applications that require fast, efficient navigation or travel that closely resembles real-world behavior, real walking has advantages over common joystick-based virtual travel techniques.

Why are You Late?: Investigating the Role of Time Management in Time-Based Prospective Memory

PubMed Central

Waldum, Emily R; McDaniel, Mark A.

2016-01-01

Time-based prospective memory tasks (TBPM) are those that are to be performed at a specific future time. Contrary to typical laboratory TBPM tasks (e.g., “hit the “z” key every 5 minutes”), many real-world TBPM tasks require more complex time-management processes. For instance to attend an appointment on time, one must estimate the duration of the drive to the appointment and then utilize this estimate to create and execute a secondary TBPM intention (e.g., “I need to start driving by 1:30 to make my 2:00 appointment on time”). Future under- and overestimates of drive time can lead to inefficient TBPM performance with the former lending to missed appointments and the latter to long stints in the waiting room. Despite the common occurrence of complex TBPM tasks in everyday life, to date, no studies have investigated how components of time management, including time estimation, affect behavior in such complex TBPM tasks. Therefore, the current study aimed to investigate timing biases in both older and younger adults and further to determine how such biases along with additional time management components including planning and plan fidelity influence complex TBPM performance. Results suggest for the first time that younger and older adults do not always utilize similar timing strategies, and as a result, can produce differential timing biases under the exact same environmental conditions. These timing biases, in turn, play a vital role in how efficiently both younger and older adults perform a later TBPM task that requires them to utilize their earlier time estimate. PMID:27336325

Using Information and Communication Technologies to Motivate Young Learners to Practice English as a Foreign Language in Cyprus

ERIC Educational Resources Information Center

Diakou, Maria

2015-01-01

Information and Communication Technologies (ICT) are continuously evolving and when integrated appropriately these can facilitate foreign language learning classes. Connecting the curriculum to real world tasks in this way prepares "learners for the challenge of coping with the language they hear and read in the real world outside the…

Investigating Comprehension in Real World Tasks: Understanding Jury Instructions.

ERIC Educational Resources Information Center

Charrow, Veda R.; Charrow, Robert

This paper discusses the results of part of an ongoing project studying an aspect of real world language usage, the comprehension of standard jury instructions. Problems in the comprehension of these instructions include the memory load that they impose, the fact that most instructions are read only once, and the fact that instructions are written…

An Analysis of Pre-Service Mathematics Teachers' Performance in Modelling Tasks in Terms of Spatial Visualisation Ability

ERIC Educational Resources Information Center

Tasova, Halil Ibrahim; Delice, Ali

2012-01-01

Mathematical modelling involves mathematical constructions chosen to represent some real world situations and the relationships among them; it is the process of expressing a real world situation mathematically. Visualisation can play a significant role in the development of thinking or understanding mathematical concepts, and also makes abstract…

Venture Evaluation and Review Technique (VERT). Users’/Analysts’ Manual

DTIC Science & Technology

1979-10-01

real world. Additionally, activity pro- cessing times could be entered as a normal, uniform or triangular distribution. Activity times can also be...work or tasks, or if the unit activities are such abstractions of the real world that the estimation of the time , cost and performance parameters for...utilized in that con- straining capacity. 7444 The network being processed has passed all the previous error checks. It currently has a real time

Vigilance in the Laboratory Predicts Avoidance in the Real World: A Dimensional Analysis of Neural, Behavioral, and Ecological Momentary Data in Anxious Youth

PubMed Central

Silk, Jennifer S.; Ladouceur, Cecile D.; Ryan, Neal D.; Dahl, Ronald E.; Forbes, Erika E.; Siegle, Greg J.

2016-01-01

Vigilance and avoidance of threat are observed in anxious adults during laboratory tasks, and are posited to have real-world clinical relevance, but data are mixed in anxious youth. We propose that vigilance-avoidance patterns will become evident in anxious youth through a focus on individual differences and real-world strategic avoidance. Decreased functional connectivity between the amygdala and prefrontal cortex (PFC) could play a mechanistic role in this link. 78 clinically anxious youth completed a dot-probe task to assess vigilance to threat while undergoing fMRI. Real-world avoidance was assessed using Ecological Momentary Assessment (EMA) of self-reported suppression and distraction during negative life events. Vigilance towards threat was positively associated with EMA distraction and suppression. Functional connectivity between a right amygdala seed region and dorsomedial and right dorsolateral PFC regions was inversely related to EMA distraction. Dorsolateral PFC-amygdalar connectivity statistically mediated the relationship between attentional vigilance and real-world distraction. Findings suggest anxious youth showing attentional vigilance toward threat are more likely to use suppression and distraction to regulate negative emotions. Reduced PFC control over limbic reactivity is a possible neural substrate of this pattern. These findings lend ecological validity to laboratory vigilance assessments and suggest PFC-amygdalar connectivity is a neural mechanism bridging laboratory and naturalistic contexts. PMID:27010577

Optimization-based decision support to assist in logistics planning for hospital evacuations.

PubMed

Glick, Roger; Bish, Douglas R; Agca, Esra

2013-01-01

The evacuation of the hospital is a very complex process and evacuation planning is an important part of a hospital's emergency management plan. There are numerous factors that affect the evacuation plan including the nature of threat, availability of resources and staff the characteristics of the evacuee population, and risk to patients and staff. The safety and health of patients is of fundamental importance, but safely moving patients to alternative care facilities while under threat is a very challenging task. This article describes the logistical issues and complexities involved in planning and execution of hospital evacuations. Furthermore, this article provides examples of how optimization-based decision support tools can help evacuation planners to better plan for complex evacuations by providing real-world solutions to various evacuation scenarios.

Whatever Gave You That Idea? False Memories Following Equivalence Training: A Behavioral Account of the Misinformation Effect

PubMed Central

Challies, Danna M; Hunt, Maree; Garry, Maryanne; Harper, David N

2011-01-01

The misinformation effect is a term used in the cognitive psychological literature to describe both experimental and real-world instances in which misleading information is incorporated into an account of an historical event. In many real-world situations, it is not possible to identify a distinct source of misinformation, and it appears that the witness may have inferred a false memory by integrating information from a variety of sources. In a stimulus equivalence task, a small number of trained relations between some members of a class of arbitrary stimuli result in a large number of untrained, or emergent relations, between all members of the class. Misleading information was introduced into a simple memory task between a learning phase and a recognition test by means of a match-to-sample stimulus equivalence task that included both stimuli from the original learning task and novel stimuli. At the recognition test, participants given equivalence training were more likely to misidentify patterns than those who were not given such training. The misinformation effect was distinct from the effects of prior stimulus exposure, or partial stimulus control. In summary, stimulus equivalence processes may underlie some real-world manifestations of the misinformation effect. PMID:22084495

Good Practices for Real-World Data Studies of Treatment and/or Comparative Effectiveness: Recommendations from the Joint ISPOR-ISPE Special Task Force on Real-World Evidence in Health Care Decision Making.

PubMed

Berger, Marc L; Sox, Harold; Willke, Richard J; Brixner, Diana L; Eichler, Hans-Georg; Goettsch, Wim; Madigan, David; Makady, Amr; Schneeweiss, Sebastian; Tarricone, Rosanna; Wang, Shirley V; Watkins, John; Mullins, C Daniel

2017-09-01

Real-world evidence (RWE) includes data from retrospective or prospective observational studies and observational registries and provides insights beyond those addressed by randomized controlled trials. RWE studies aim to improve health care decision making. The International Society for Pharmacoeconomics and Outcomes Research (ISPOR) and the International Society for Pharmacoepidemiology (ISPE) created a task force to make recommendations regarding good procedural practices that would enhance decision makers' confidence in evidence derived from RWD studies. Peer review by ISPOR/ISPE members and task force participants provided a consensus-building iterative process for the topics and framing of recommendations. The ISPOR/ISPE Task Force recommendations cover seven topics such as study registration, replicability, and stakeholder involvement in RWE studies. These recommendations, in concert with earlier recommendations about study methodology, provide a trustworthy foundation for the expanded use of RWE in health care decision making. The focus of these recommendations is good procedural practices for studies that test a specific hypothesis in a specific population. We recognize that some of the recommendations in this report may not be widely adopted without appropriate incentives from decision makers, journal editors, and other key stakeholders. Copyright © 2017. Published by Elsevier Inc.

Inhibitory motor control based on complex stopping goals relies on the same brain network as simple stopping

PubMed Central

Wessel, Jan R.; Aron, Adam R.

2014-01-01

Much research has modeled action-stopping using the stop-signal task (SST), in which an impending response has to be stopped when an explicit stop-signal occurs. A limitation of the SST is that real-world action-stopping rarely involves explicit stop-signals. Instead, the stopping-system engages when environmental features match more complex stopping goals. For example, when stepping into the street, one monitors path, velocity, size, and types of objects; and only stops if there is a vehicle approaching. Here, we developed a task in which participants compared the visual features of a multidimensional go-stimulus to a complex stopping-template, and stopped their go-response if all features matched the template. We used independent component analysis of EEG data to show that the same motor inhibition brain network that explains action-stopping in the SST also implements motor inhibition in the complex-stopping task. Furthermore, we found that partial feature overlap between go-stimulus and stopping-template lead to motor slowing, which also corresponded with greater stopping-network activity. This shows that the same brain system for action-stopping to explicit stop-signals is recruited to slow or stop behavior when stimuli match a complex stopping goal. The results imply a generalizability of the brain’s network for simple action-stopping to more ecologically valid scenarios. PMID:25270603

Traffic light detection and intersection crossing using mobile computer vision

NASA Astrophysics Data System (ADS)

Grewei, Lynne; Lagali, Christopher

2017-05-01

The solution for Intersection Detection and Crossing to support the development of blindBike an assisted biking system for the visually impaired is discussed. Traffic light detection and intersection crossing are key needs in the task of biking. These problems are tackled through the use of mobile computer vision, in the form of a mobile application on an Android phone. This research builds on previous Traffic Light detection algorithms with a focus on efficiency and compatibility on a resource-limited platform. Light detection is achieved through blob detection algorithms utilizing training data to detect patterns of Red, Green and Yellow in complex real world scenarios where multiple lights may be present. Also, issues of obscurity and scale are addressed. Safe Intersection crossing in blindBike is also discussed. This module takes a conservative "assistive" technology approach. To achieve this blindBike use's not only the Android device but, an external bike cadence Bluetooth/Ant enabled sensor. Real world testing results are given and future work is discussed.

Effects of statistical learning on the acquisition of grammatical categories through Qur'anic memorization: A natural experiment.

PubMed

Zuhurudeen, Fathima Manaar; Huang, Yi Ting

2016-03-01

Empirical evidence for statistical learning comes from artificial language tasks, but it is unclear how these effects scale up outside of the lab. The current study turns to a real-world test case of statistical learning where native English speakers encounter the syntactic regularities of Arabic through memorization of the Qur'an. This unique input provides extended exposure to the complexity of a natural language, with minimal semantic cues. Memorizers were asked to distinguish unfamiliar nouns and verbs based on their co-occurrence with familiar pronouns in an Arabic language sample. Their performance was compared to that of classroom learners who had explicit knowledge of pronoun meanings and grammatical functions. Grammatical judgments were more accurate in memorizers compared to non-memorizers. No effects of classroom experience were found. These results demonstrate that real-world exposure to the statistical properties of a natural language facilitates the acquisition of grammatical categories. Copyright © 2015 Elsevier B.V. All rights reserved.

Assessment of pilot workload - Converging measures from performance based, subjective and psychophysiological techniques

NASA Technical Reports Server (NTRS)

Kramer, Arthur F.; Sirevaag, Erik J.; Braune, Rolf

1986-01-01

This study explores the relationship between the P300 component of the event-related brain potential (ERP) and the processing demands of a complex real-world task. Seven male volunteers enrolled in an Instrument Flight Rule (IFR) aviation course flew a series of missions in a single engine fixed-based simulator. In dual task conditions subjects were also required to discriminate between two tones differing in frequency. ERPs time-locked to the tones, subjective effort ratings and overt performance measures were collected during two 45 min flights differing in difficulty (manipulated by varying both atmospheric conditions and instrument reliability). The more difficult flight was associated with poorer performance, increased subjective effort ratings, and smaller secondary task P300s. Within each flight, P300 amplitude was negatively correlated with deviations from command headings indicating that P300 amplitude was a sensitive workload metric both between and within the flight missions.

Synthetic perspective optical flow: Influence on pilot control tasks

NASA Technical Reports Server (NTRS)

Bennett, C. Thomas; Johnson, Walter W.; Perrone, John A.; Phatak, Anil V.

1989-01-01

One approach used to better understand the impact of visual flow on control tasks has been to use synthetic perspective flow patterns. Such patterns are the result of apparent motion across a grid or random dot display. Unfortunately, the optical flow so generated is based on a subset of the flow information that exists in the real world. The danger is that the resulting optical motions may not generate the visual flow patterns useful for actual flight control. Researchers conducted a series of studies directed at understanding the characteristics of synthetic perspective flow that support various pilot tasks. In the first of these, they examined the control of altitude over various perspective grid textures (Johnson et al., 1987). Another set of studies was directed at studying the head tracking of targets moving in a 3-D coordinate system. These studies, parametric in nature, utilized both impoverished and complex virtual worlds represented by simple perspective grids at one extreme, and computer-generated terrain at the other. These studies are part of an applied visual research program directed at understanding the design principles required for the development of instruments displaying spatial orientation information. The experiments also highlight the need for modeling the impact of spatial displays on pilot control tasks.

Applications of neural networks to landmark detection in 3-D surface data

NASA Astrophysics Data System (ADS)

Arndt, Craig M.

1992-09-01

The problem of identifying key landmarks in 3-dimensional surface data is of considerable interest in solving a number of difficult real-world tasks, including object recognition and image processing. The specific problem that we address in this research is to identify the specific landmarks (anatomical) in human surface data. This is a complex task, currently performed visually by an expert human operator. In order to replace these human operators and increase reliability of the data acquisition, we need to develop a computer algorithm which will utilize the interrelations between the 3-dimensional data to identify the landmarks of interest. The current presentation describes a method for designing, implementing, training, and testing a custom architecture neural network which will perform the landmark identification task. We discuss the performance of the net in relationship to human performance on the same task and how this net has been integrated with other AI and traditional programming methods to produce a powerful analysis tool for computer anthropometry.

Where Good Pedagogical Ideas Come From: The Story of an EAP Task

ERIC Educational Resources Information Center

Light, Justine; Ranta, Leila

2016-01-01

Teachers using a task-based language teaching (TBLT) approach are always searching for learning tasks that have the potential to prepare learners for the real world. In this article, we describe how an authentic academic assignment for graduate students in a teaching English as a second language (TESL) course was transformed into a task-based…

Comprehending Comprehension: Selected Possibilities for Clinical Practice Within a Multidimensional Model.

PubMed

Wallach, Geraldine P; Ocampo, Alaine

2017-04-20

In this discussion as part of a response to Catts and Kamhi's "Prologue: Reading Comprehension Is Not a Single Activity" (2017), the authors provide selected examples from 4th-, 5th-, and 6th-grade texts to demonstrate, in agreement with Catts and Kamhi, that reading comprehension is a multifaceted and complex ability. The authors were asked to provide readers with evidence-based practices that lend support to applications of a multidimensional model of comprehension. We present examples from the reading comprehension literature that support the notion that reading is a complex set of abilities that include a reader's ability, especially background knowledge; the type of text the reader is being asked to comprehend; and the task or technique used in assessment or intervention paradigms. An intervention session from 6th grade serves to demonstrate how background knowledge, a text's demands, and tasks may come together in the real world as clinicians and educators aim to help students comprehend complex material. The authors agree with the conceptual framework proposed by Catts and Kamhi that clinicians and educators should consider the multidimensional nature of reading comprehension (an interaction of reader, text, and task) when creating assessment and intervention programs. The authors might depart slightly by considering, more closely, those reading comprehension strategies that might facilitate comprehension across texts and tasks with an understanding of students' individual needs at different points in time.

Why are you late? Investigating the role of time management in time-based prospective memory.

PubMed

Waldum, Emily R; McDaniel, Mark A

2016-08-01

Time-based prospective memory tasks (TBPM) are those that are to be performed at a specific future time. Contrary to typical laboratory TBPM tasks (e.g., hit the Z key every 5 min), many real-world TBPM tasks require more complex time-management processes. For instance, to attend an appointment on time, one must estimate the duration of the drive to the appointment and then use this estimate to create and execute a secondary TBPM intention (e.g., "I need to start driving by 1:30 to make my 2:00 appointment on time"). Future under- and overestimates of drive time can lead to inefficient TBPM performance with the former lending to missed appointments and the latter to long stints in the waiting room. Despite the common occurrence of complex TBPM tasks in everyday life, to date, no studies have investigated how components of time management, including time estimation, affect behavior in such complex TBPM tasks. Therefore, the current study aimed to investigate timing biases in both older and younger adults and, further, to determine how such biases along with additional time management components including planning and plan fidelity influence complex TBPM performance. Results suggest for the first time that younger and older adults do not always utilize similar timing strategies, and as a result, can produce differential timing biases under the exact same environmental conditions. These timing biases, in turn, play a vital role in how efficiently both younger and older adults perform a later TBPM task that requires them to utilize their earlier time estimate. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Learning the Task Management Space of an Aircraft Approach Model

NASA Technical Reports Server (NTRS)

Krall, Joseph; Menzies, Tim; Davies, Misty

2014-01-01

Validating models of airspace operations is a particular challenge. These models are often aimed at finding and exploring safety violations, and aim to be accurate representations of real-world behavior. However, the rules governing the behavior are quite complex: nonlinear physics, operational modes, human behavior, and stochastic environmental concerns all determine the responses of the system. In this paper, we present a study on aircraft runway approaches as modeled in Georgia Tech's Work Models that Compute (WMC) simulation. We use a new learner, Genetic-Active Learning for Search-Based Software Engineering (GALE) to discover the Pareto frontiers defined by cognitive structures. These cognitive structures organize the prioritization and assignment of tasks of each pilot during approaches. We discuss the benefits of our approach, and also discuss future work necessary to enable uncertainty quantification.

Field measurement of naturalistic backing behavior

DOT National Transportation Integrated Search

1997-02-01

A series of observations and measurements were made as 21 subjects drove their own vehicles in an assortment of naturalistic backing tasks. The tasks were performed on public roads in real world driving conditions. As the subjects performed the eight...

ICA-Derived EEG Correlates to Mental Fatigue, Effort, and Workload in a Realistically Simulated Air Traffic Control Task.

PubMed

Dasari, Deepika; Shou, Guofa; Ding, Lei

2017-01-01

Electroencephalograph (EEG) has been increasingly studied to identify distinct mental factors when persons perform cognitively demanding tasks. However, most of these studies examined EEG correlates at channel domain, which suffers the limitation that EEG signals are the mixture of multiple underlying neuronal sources due to the volume conduction effect. Moreover, few studies have been conducted in real-world tasks. To precisely probe EEG correlates with specific neural substrates to mental factors in real-world tasks, the present study examined EEG correlates to three mental factors, i.e., mental fatigue [also known as time-on-task (TOT) effect], workload and effort, in EEG component signals, which were obtained using an independent component analysis (ICA) on high-density EEG data. EEG data were recorded when subjects performed a realistically simulated air traffic control (ATC) task for 2 h. Five EEG independent component (IC) signals that were associated with specific neural substrates (i.e., the frontal, central medial, motor, parietal, occipital areas) were identified. Their spectral powers at their corresponding dominant bands, i.e., the theta power of the frontal IC and the alpha power of the other four ICs, were detected to be correlated to mental workload and effort levels, measured by behavioral metrics. Meanwhile, a linear regression analysis indicated that spectral powers at five ICs significantly increased with TOT. These findings indicated that different levels of mental factors can be sensitively reflected in EEG signals associated with various brain functions, including visual perception, cognitive processing, and motor outputs, in real-world tasks. These results can potentially aid in the development of efficient operational interfaces to ensure productivity and safety in ATC and beyond.

Vigilance in the laboratory predicts avoidance in the real world: A dimensional analysis of neural, behavioral, and ecological momentary data in anxious youth.

PubMed

Price, Rebecca B; Allen, Kristy Benoit; Silk, Jennifer S; Ladouceur, Cecile D; Ryan, Neal D; Dahl, Ronald E; Forbes, Erika E; Siegle, Greg J

2016-06-01

Vigilance and avoidance of threat are observed in anxious adults during laboratory tasks, and are posited to have real-world clinical relevance, but data are mixed in anxious youth. We propose that vigilance-avoidance patterns will become evident in anxious youth through a focus on individual differences and real-world strategic avoidance. Decreased functional connectivity between the amygdala and prefrontal cortex (PFC) could play a mechanistic role in this link. 78 clinically anxious youth completed a dot-probe task to assess vigilance to threat while undergoing fMRI. Real-world avoidance was assessed using Ecological Momentary Assessment (EMA) of self-reported suppression and distraction during negative life events. Vigilance toward threat was positively associated with EMA distraction and suppression. Functional connectivity between a right amygdala seed region and dorsomedial and right dorsolateral PFC regions was inversely related to EMA distraction. Dorsolateral PFC-amygdalar connectivity statistically mediated the relationship between attentional vigilance and real-world distraction. Findings suggest anxious youth showing attentional vigilance toward threat are more likely to use suppression and distraction to regulate negative emotions. Reduced PFC control over limbic reactivity is a possible neural substrate of this pattern. These findings lend ecological validity to laboratory vigilance assessments and suggest PFC-amygdalar connectivity is a neural mechanism bridging laboratory and naturalistic contexts. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Cognitive and neural plasticity in older adults’ prospective memory following training with the Virtual Week computer game

PubMed Central

Rose, Nathan S.; Rendell, Peter G.; Hering, Alexandra; Kliegel, Matthias; Bidelman, Gavin M.; Craik, Fergus I. M.

2015-01-01

Prospective memory (PM) – the ability to remember and successfully execute our intentions and planned activities – is critical for functional independence and declines with age, yet few studies have attempted to train PM in older adults. We developed a PM training program using the Virtual Week computer game. Trained participants played the game in 12, 1-h sessions over 1 month. Measures of neuropsychological functions, lab-based PM, event-related potentials (ERPs) during performance on a lab-based PM task, instrumental activities of daily living, and real-world PM were assessed before and after training. Performance was compared to both no-contact and active (music training) control groups. PM on the Virtual Week game dramatically improved following training relative to controls, suggesting PM plasticity is preserved in older adults. Relative to control participants, training did not produce reliable transfer to laboratory-based tasks, but was associated with a reduction of an ERP component (sustained negativity over occipito-parietal cortex) associated with processing PM cues, indicative of more automatic PM retrieval. Most importantly, training produced far transfer to real-world outcomes including improvements in performance on real-world PM and activities of daily living. Real-world gains were not observed in either control group. Our findings demonstrate that short-term training with the Virtual Week game produces cognitive and neural plasticity that may result in real-world benefits to supporting functional independence in older adulthood. PMID:26578936

From Apollo to Cognac

NASA Technical Reports Server (NTRS)

1980-01-01

Shell Oil Company started oil and gas production from a new offshore platform called Cognac located in the Gulf of Mexico. It is the world's tallest oil platform, slightly taller than the Empire State Building. The highly complex job of installing Cognac's support "jacket" under water more than a thousand feet deep was directed from a barge-based control center. To enable crews to practice in advance difficult tasks never before accomplished, Honeywell, adapting NASA's Apollo technology, developed a system for simulating the various underwater operations. In training sessions, displays and controls reacted exactly as they would in real operation.

Robot, computer problem solving system

NASA Technical Reports Server (NTRS)

Becker, J. D.

1972-01-01

The development of a computer problem solving system is reported that considers physical problems faced by an artificial robot moving around in a complex environment. Fundamental interaction constraints with a real environment are simulated for the robot by visual scan and creation of an internal environmental model. The programming system used in constructing the problem solving system for the simulated robot and its simulated world environment is outlined together with the task that the system is capable of performing. A very general framework for understanding the relationship between an observed behavior and an adequate description of that behavior is included.

Minimum time search in uncertain dynamic domains with complex sensorial platforms.

PubMed

Lanillos, Pablo; Besada-Portas, Eva; Lopez-Orozco, Jose Antonio; de la Cruz, Jesus Manuel

2014-08-04

The minimum time search in uncertain domains is a searching task, which appears in real world problems such as natural disasters and sea rescue operations, where a target has to be found, as soon as possible, by a set of sensor-equipped searchers. The automation of this task, where the time to detect the target is critical, can be achieved by new probabilistic techniques that directly minimize the Expected Time (ET) to detect a dynamic target using the observation probability models and actual observations collected by the sensors on board the searchers. The selected technique, described in algorithmic form in this paper for completeness, has only been previously partially tested with an ideal binary detection model, in spite of being designed to deal with complex non-linear/non-differential sensorial models. This paper covers the gap, testing its performance and applicability over different searching tasks with searchers equipped with different complex sensors. The sensorial models under test vary from stepped detection probabilities to continuous/discontinuous differentiable/non-differentiable detection probabilities dependent on distance, orientation, and structured maps. The analysis of the simulated results of several static and dynamic scenarios performed in this paper validates the applicability of the technique with different types of sensor models.

Minimum Time Search in Uncertain Dynamic Domains with Complex Sensorial Platforms

PubMed Central

Lanillos, Pablo; Besada-Portas, Eva; Lopez-Orozco, Jose Antonio; de la Cruz, Jesus Manuel

2014-01-01

The minimum time search in uncertain domains is a searching task, which appears in real world problems such as natural disasters and sea rescue operations, where a target has to be found, as soon as possible, by a set of sensor-equipped searchers. The automation of this task, where the time to detect the target is critical, can be achieved by new probabilistic techniques that directly minimize the Expected Time (ET) to detect a dynamic target using the observation probability models and actual observations collected by the sensors on board the searchers. The selected technique, described in algorithmic form in this paper for completeness, has only been previously partially tested with an ideal binary detection model, in spite of being designed to deal with complex non-linear/non-differential sensorial models. This paper covers the gap, testing its performance and applicability over different searching tasks with searchers equipped with different complex sensors. The sensorial models under test vary from stepped detection probabilities to continuous/discontinuous differentiable/non-differentiable detection probabilities dependent on distance, orientation, and structured maps. The analysis of the simulated results of several static and dynamic scenarios performed in this paper validates the applicability of the technique with different types of sensor models. PMID:25093345

A Selective Review of Simulated Driving Studies: Combining Naturalistic and Hybrid Paradigms, Analysis Approaches, and Future Directions

PubMed Central

Calhoun, V. D.; Pearlson, G. D.

2011-01-01

Naturalistic paradigms such as movie watching or simulated driving that mimic closely real-world complex activities are becoming more widely used in functional magnetic resonance imaging (fMRI) studies both because of their ability to robustly stimulate brain connectivity and the availability of analysis methods which are able to capitalize on connectivity within and among intrinsic brain networks identified both during a task and in resting fMRI data. In this paper we review over a decade of work from our group and others on the use of simulated driving paradigms to study both the healthy brain as well as the effects of acute alcohol administration on functional connectivity during such paradigms. We briefly review our initial work focused on the configuration of the driving simulator and the analysis strategies. We then describe in more detail several recent studies from our group including a hybrid study examining distracted driving and compare resulting data with those from a separate visual oddball task. The analysis of these data were performed primarily using a combination of group independent component analysis (ICA) and the general linear model (GLM) and in the various studies we highlight novel findings which result from an analysis of either 1) within-network connectivity, 2) inter-network connectivity, also called functional network connectivity, or 3) the degree to which the modulation of the various intrinsic networks were associated with the alcohol administration and the task context. Despite the fact that the behavioral effects of alcohol intoxication are relatively well known, there is still much to discover on how acute alcohol exposure modulates brain function in a selective manner, associated with behavioral alterations. Through the above studies, we have learned more regarding the impact of acute alcohol intoxication on organization of the brain’s intrinsic connectivity networks during performance of a complex, real-world cognitive operation. Lessons learned from the above studies have broader applicability to designing ecologically valid, complex, functional MRI cognitive paradigms and incorporating pharmacologic challenges into such studies. Overall, the use of hybrid driving studies is a particularly promising area of neuroscience investigation. PMID:21718791

Easy rider: monkeys learn to drive a wheelchair to navigate through a complex maze.

PubMed

Etienne, Stephanie; Guthrie, Martin; Goillandeau, Michel; Nguyen, Tho Hai; Orignac, Hugues; Gross, Christian; Boraud, Thomas

2014-01-01

The neurological bases of spatial navigation are mainly investigated in rodents and seldom in primates. The few studies led on spatial navigation in both human and non-human primates are performed in virtual, not in real environments. This is mostly because of methodological difficulties inherent in conducting research on freely-moving monkeys in real world environments. There is some incertitude, however, regarding the extrapolation of rodent spatial navigation strategies to primates. Here we present an entirely new platform for investigating real spatial navigation in rhesus monkeys. We showed that monkeys can learn a pathway by using different strategies. In these experiments three monkeys learned to drive the wheelchair and to follow a specified route through a real maze. After learning the route, probe tests revealed that animals successively use three distinct navigation strategies based on i) the place of the reward, ii) the direction taken to obtain reward or iii) a cue indicating reward location. The strategy used depended of the options proposed and the duration of learning. This study reveals that monkeys, like rodents and humans, switch between different spatial navigation strategies with extended practice, implying well-conserved brain learning systems across different species. This new task with freely driving monkeys provides a good support for the electrophysiological and pharmacological investigation of spatial navigation in the real world by making possible electrophysiological and pharmacological investigations.

Network structure exploration in networks with node attributes

NASA Astrophysics Data System (ADS)

Chen, Yi; Wang, Xiaolong; Bu, Junzhao; Tang, Buzhou; Xiang, Xin

2016-05-01

Complex networks provide a powerful way to represent complex systems and have been widely studied during the past several years. One of the most important tasks of network analysis is to detect structures (also called structural regularities) embedded in networks by determining group number and group partition. Most of network structure exploration models only consider network links. However, in real world networks, nodes may have attributes that are useful for network structure exploration. In this paper, we propose a novel Bayesian nonparametric (BNP) model to explore structural regularities in networks with node attributes, called Bayesian nonparametric attribute (BNPA) model. This model does not only take full advantage of both links between nodes and node attributes for group partition via shared hidden variables, but also determine group number automatically via the Bayesian nonparametric theory. Experiments conducted on a number of real and synthetic networks show that our BNPA model is able to automatically explore structural regularities in networks with node attributes and is competitive with other state-of-the-art models.

Good practices for real-world data studies of treatment and/or comparative effectiveness: Recommendations from the joint ISPOR-ISPE Special Task Force on real-world evidence in health care decision making.

PubMed

Berger, Marc L; Sox, Harold; Willke, Richard J; Brixner, Diana L; Eichler, Hans-Georg; Goettsch, Wim; Madigan, David; Makady, Amr; Schneeweiss, Sebastian; Tarricone, Rosanna; Wang, Shirley V; Watkins, John; Daniel Mullins, C

2017-09-01

Real-world evidence (RWE) includes data from retrospective or prospective observational studies and observational registries and provides insights beyond those addressed by randomized controlled trials. RWE studies aim to improve health care decision making. The International Society for Pharmacoeconomics and Outcomes Research (ISPOR) and the International Society for Pharmacoepidemiology (ISPE) created a task force to make recommendations regarding good procedural practices that would enhance decision makers' confidence in evidence derived from RWD studies. Peer review by ISPOR/ISPE members and task force participants provided a consensus-building iterative process for the topics and framing of recommendations. The ISPOR/ISPE Task Force recommendations cover seven topics such as study registration, replicability, and stakeholder involvement in RWE studies. These recommendations, in concert with earlier recommendations about study methodology, provide a trustworthy foundation for the expanded use of RWE in health care decision making. The focus of these recommendations is good procedural practices for studies that test a specific hypothesis in a specific population. We recognize that some of the recommendations in this report may not be widely adopted without appropriate incentives from decision makers, journal editors, and other key stakeholders. © 2017 The Authors. Pharmacoepidemiology & Drug Safety published by John Wiley & Sons Ltd.

Game theory and extremal optimization for community detection in complex dynamic networks.

PubMed

Lung, Rodica Ioana; Chira, Camelia; Andreica, Anca

2014-01-01

The detection of evolving communities in dynamic complex networks is a challenging problem that recently received attention from the research community. Dynamics clearly add another complexity dimension to the difficult task of community detection. Methods should be able to detect changes in the network structure and produce a set of community structures corresponding to different timestamps and reflecting the evolution in time of network data. We propose a novel approach based on game theory elements and extremal optimization to address dynamic communities detection. Thus, the problem is formulated as a mathematical game in which nodes take the role of players that seek to choose a community that maximizes their profit viewed as a fitness function. Numerical results obtained for both synthetic and real-world networks illustrate the competitive performance of this game theoretical approach.

Student Engagement: A Framework for On-Demand Performance Assessment Tasks

ERIC Educational Resources Information Center

Taylor, Catherine; Kokka, Kari; Darling-Hammond, Linda; Dieckmann, Jack; Pacheco, Vivian Santana; Sandler, Susan; Bae, Soung

2016-01-01

Engaging students in meaningful applications of their knowledge is a key aspect of both addressing the standards and providing greater access. Not only do the standards emphasize the importance of meaningful engagement in real-world tasks, but evidence shows that engagement is strongly related to student performance on assessment tasks, especially…

Description and Prediction of Age-Related Change in Everyday Task Performance.

ERIC Educational Resources Information Center

Marsiske, Michael; Willis, Sherry L.

Traditionally, assessment of the cognitive competencies of older adults has focused on abstract laboratory tests, which have often seemed quite unlike the demands of tasks encountered in everyday activities. Consequently, external validity of these laboratory tasks has been questioned, and their utility for assessing real-world competence has been…

Field Measurement Of Naturalistic Backing Behavior, Technical Report

DOT National Transportation Integrated Search

1995-12-01

A SERIES OF OBSERVATIONS AND MEASUREMENTS WERE MADE AS 21 SUBJECTS DROVE THEIR OWN VEHICLES IN AN ASSORTMENT OF NATURALISTIC BACKING TASKS. THE TASKS WERE PERFORMED ON PUBLIC ROADS IN REAL WORLD DRIVING CONDITIONS. AS THE SUBJECTS PERFORMED THE EIGHT...

Spontaneous mentalizing during an interactive real world task: an fMRI study.

PubMed

Spiers, Hugo J; Maguire, Eleanor A

2006-01-01

There are moments in everyday life when we need to consider the thoughts and intentions of other individuals in order to act in a socially appropriate manner. Most of this mentalizing occurs spontaneously as we go about our business in the complexity of the real world. As such, studying the neural basis of spontaneous mentalizing has been virtually impossible. Here we devised a means to achieve this by employing a unique combination of functional magnetic resonance imaging (fMRI), a detailed and interactive virtual reality simulation of a bustling familiar city, and a retrospective verbal report protocol. We were able to provide insights into the content of spontaneous mentalizing events and identify the brain regions that underlie them. We found increased activity in a number of regions, namely the right posterior superior temporal sulcus, the medial prefrontal cortex and the right temporal pole associated with spontaneous mentalizing. Furthermore, we observed the right posterior superior temporal sulcus to be consistently active during several different subtypes of mentalizing events. By contrast, medial prefrontal cortex seemed to be particularly involved in thinking about agents that were visible in the environment. Our findings show that it is possible to investigate the neural basis of mentalizing in a manner closer to its true context, the real world, opening up intriguing possibilities for making comparisons with those who have mentalizing problems.

Transfer of Complex Skill Learning from Virtual to Real Rowing

PubMed Central

Rauter, Georg; Sigrist, Roland; Koch, Claudio; Crivelli, Francesco; van Raai, Mark; Riener, Robert; Wolf, Peter

2013-01-01

Simulators are commonly used to train complex tasks. In particular, simulators are applied to train dangerous tasks, to save costs, and to investigate the impact of different factors on task performance. However, in most cases, the transfer of simulator training to the real task has not been investigated. Without a proof for successful skill transfer, simulators might not be helpful at all or even counter-productive for learning the real task. In this paper, the skill transfer of complex technical aspects trained on a scull rowing simulator to sculling on water was investigated. We assume if a simulator provides high fidelity rendering of the interactions with the environment even without augmented feedback, training on such a realistic simulator would allow similar skill gains as training in the real environment. These learned skills were expected to transfer to the real environment. Two groups of four recreational rowers participated. One group trained on water, the other group trained on a simulator. Within two weeks, both groups performed four training sessions with the same licensed rowing trainer. The development in performance was assessed by quantitative biomechanical performance measures and by a qualitative video evaluation of an independent, blinded trainer. In general, both groups could improve their performance on water. The used biomechanical measures seem to allow only a limited insight into the rowers' development, while the independent trainer could also rate the rowers' overall impression. The simulator quality and naturalism was confirmed by the participants in a questionnaire. In conclusion, realistic simulator training fostered skill gains to a similar extent as training in the real environment and enabled skill transfer to the real environment. In combination with augmented feedback, simulator training can be further exploited to foster motor learning even to a higher extent, which is subject to future work. PMID:24376518

Air-Track: a real-world floating environment for active sensing in head-fixed mice.

PubMed

Nashaat, Mostafa A; Oraby, Hatem; Sachdev, Robert N S; Winter, York; Larkum, Matthew E

2016-10-01

Natural behavior occurs in multiple sensory and motor modalities and in particular is dependent on sensory feedback that constantly adjusts behavior. To investigate the underlying neuronal correlates of natural behavior, it is useful to have access to state-of-the-art recording equipment (e.g., 2-photon imaging, patch recordings, etc.) that frequently requires head fixation. This limitation has been addressed with various approaches such as virtual reality/air ball or treadmill systems. However, achieving multimodal realistic behavior in these systems can be challenging. These systems are often also complex and expensive to implement. Here we present "Air-Track," an easy-to-build head-fixed behavioral environment that requires only minimal computational processing. The Air-Track is a lightweight physical maze floating on an air table that has all the properties of the "real" world, including multiple sensory modalities tightly coupled to motor actions. To test this system, we trained mice in Go/No-Go and two-alternative forced choice tasks in a plus maze. Mice chose lanes and discriminated apertures or textures by moving the Air-Track back and forth and rotating it around themselves. Mice rapidly adapted to moving the track and used visual, auditory, and tactile cues to guide them in performing the tasks. A custom-controlled camera system monitored animal location and generated data that could be used to calculate reaction times in the visual and somatosensory discrimination tasks. We conclude that the Air-Track system is ideal for eliciting natural behavior in concert with virtually any system for monitoring or manipulating brain activity. Copyright © 2016 the American Physiological Society.

Identifying protein complexes in PPI network using non-cooperative sequential game.

PubMed

Maulik, Ujjwal; Basu, Srinka; Ray, Sumanta

2017-08-21

Identifying protein complexes from protein-protein interaction (PPI) network is an important and challenging task in computational biology as it helps in better understanding of cellular mechanisms in various organisms. In this paper we propose a noncooperative sequential game based model for protein complex detection from PPI network. The key hypothesis is that protein complex formation is driven by mechanism that eventually optimizes the number of interactions within the complex leading to dense subgraph. The hypothesis is drawn from the observed network property named small world. The proposed multi-player game model translates the hypothesis into the game strategies. The Nash equilibrium of the game corresponds to a network partition where each protein either belong to a complex or form a singleton cluster. We further propose an algorithm to find the Nash equilibrium of the sequential game. The exhaustive experiment on synthetic benchmark and real life yeast networks evaluates the structural as well as biological significance of the network partitions.

Assessment of higher level cognitive-communication functions in adolescents with ABI: Standardization of the student version of the functional assessment of verbal reasoning and executive strategies (S-FAVRES).

PubMed

MacDonald, Sheila

2016-01-01

Childhood acquired brain injuries can disrupt communication functions needed for success in school, work and social interaction. Cognitive-communication difficulties may not be apparent until adolescence, when academic, environmental and social-emotional demands increase. The Functional Assessment of Verbal Reasoning and Executive Strategies for Students (S-FAVRES) is a new activity-level measure of cognitive-communication skills in complex, contextual and integrative tasks that simulate real world communication challenges. It is hypothesized that S-FAVRES performance would differentiate adolescents with and without acquired brain injury (ABI) on scores for Accuracy, Rationale, Reasoning Subskills and Time. S-FAVRES was administered to 182 typically-developing (TD) and 57 adolescents with mild-to-severe ABI aged 12-19. Group differences, internal consistency, sensitivity, specificity, reliability and contributing factors to performance (age, gender, brain injury) were examined statistically. Those with ABI attained statistically lower Accuracy, Rationale and Reasoning sub-skills scores than their TD peers. Time scores were not significantly different. Performance trends were consistent across tasks, administrations, gender and age groups. Inter-rater reliability for scoring was acceptable. The S-FAVRES provides a reliable, functional and quantifiable measure of subtle cognitive-communication difficulties in adolescents that can assist speech-language pathologists in planning treatment and integration to school and real world communication.

Role of childhood aerobic fitness in successful street crossing.

PubMed

Chaddock, Laura; Neider, Mark B; Lutz, Aubrey; Hillman, Charles H; Kramer, Arthur F

2012-04-01

Increased aerobic fitness is associated with improved cognition, brain health, and academic achievement during preadolescence. In this study, we extended these findings by examining the relationship between aerobic fitness and an everyday real-world task: street crossing. Because street crossing can be a dangerous multitask challenge and is a leading cause of injury in children, it is important to find ways to improve pedestrian safety. A street intersection was modeled in a virtual environment, and higher-fit (n = 13, 7 boys) and lower-fit (n = 13, 5 boys) 8- to 10-yr-old children, as determined by V˙O(2max) testing, navigated trafficked roads by walking on a treadmill that was integrated with an immersive virtual world. Child pedestrians crossed the street while undistracted, listening to music, or conversing on a hands-free cellular phone. Cell phones impaired street crossing success rates compared with the undistracted or music conditions for all participants (P = 0.004), a result that supports previous research. However, individual differences in aerobic fitness influenced these patterns (fitness × condition interaction, P = 0.003). Higher-fit children maintained street crossing success rates across all three conditions (paired t-tests, all P > 0.4), whereas lower-fit children showed decreased success rates when on the phone, relative to the undistracted (P = 0.018) and music (P = 0.019) conditions. The results suggest that higher levels of childhood aerobic fitness may attenuate the impairment typically associated with multitasking during street crossing. It is possible that superior cognitive abilities of higher-fit children play a role in the performance differences during complex real-world tasks.

Staring reality in the face: A comparison of social attention across laboratory and real world measures suggests little common ground.

PubMed

Hayward, Dana A; Voorhies, Willa; Morris, Jenna L; Capozzi, Francesca; Ristic, Jelena

2017-09-01

The ability to attend to someone else's gaze is thought to represent one of the essential building blocks of the human sociocognitive system. This behavior, termed social attention, has traditionally been assessed using laboratory procedures in which participants' response time and/or accuracy performance indexes attentional function. Recently, a parallel body of emerging research has started to examine social attention during real life social interactions using naturalistic and observational methodologies. The main goal of the present work was to begin connecting these two lines of inquiry. To do so, here we operationalized, indexed, and measured the engagement and shifting components of social attention using covert and overt measures. These measures were obtained during an unconstrained real-world social interaction and during a typical laboratory social cuing task. Our results indicated reliable and overall similar indices of social attention engagement and shifting within each task. However, these measures did not relate across the two tasks. We discuss these results as potentially reflecting the differences in social attention mechanisms, the specificity of the cuing task's measurement, as well as possible general dissimilarities with respect to context, task goals, and/or social presence. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Understanding Emergency Medicine Physicians Multitasking Behaviors Around Interruptions.

PubMed

Fong, Allan; Ratwani, Raj M

2018-06-11

Interruptions can adversely impact human performance, particularly in fast-paced and high-risk environments such as the emergency department (ED). Understanding physician behaviors before, during, and after interruptions is important to the design and promotion of safe and effective workflow solutions. However, traditional human factors based interruption models do not accurately reflect the complexities of real-world environments like the ED and may not capture multiple interruptions and multitasking. We present a more comprehensive framework for understanding interruptions that is composed of three phases, each with multiple levels: Interruption Start Transition, Interruption Engagement, and Interruption End Transition. This three-phase framework is not constrained to discrete task transitions, providing a robust method to categorize multitasking behaviors around interruptions. We apply this framework in categorizing 457 interruption episodes. 457 interruption episodes were captured during 36 hours of observation. The interrupted task was immediately suspended 348 (76.1%) times. Participants engaged in new self-initiated tasks during the interrupting task 164 (35.9%) times and did not directly resume the interrupted task in 284 (62.1%) interruption episodes. Using this framework provides a more detailed description of the types of physician behaviors in complex environments. Understanding the different types of interruption and resumption patterns, which may have a different impact on performance, can support the design of interruption mitigation strategies. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Planning deficits in polysubstance dependent users: Differential associations with severity of drug use and intelligence.

PubMed

Valls-Serrano, C; Verdejo-García, A; Caracuel, A

2016-05-01

Polysubstance use is associated with alterations in different components of executive functioning such as working memory and response inhibition. Nevertheless, less attention has been given to executive planning skills, which are required to benefit of low structured interventions. This study examines the association between severity of use of cocaine, heroin, alcohol, fluid and crystallized intelligence and planning tasks varying on degree of structure. Data were collected from 60 polysubstance users and 30 healthy controls. Cognitive assessment consisted of three planning tasks with different structure levels: Stockings of Cambridge, Zoo Map test, and Multiple Errands Test. Polysubstance users had significant planning deficits across the three tasks compared to healthy controls. Hierarchical regression models showed that severity of drug use and fluid and crystallized intelligence significantly explained performance in all the planning tasks. However, these associations were higher for low-structured real world tasks. These low-structured tasks also showed a unique association with crystallized but not fluid intelligence. Drug abuse is negatively associated with planning abilities, and intelligence is positively associated with planning performance in real-world tasks. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A Framework for Determining the Authenticity of Assessment Tasks: Applied to an Example in Law

ERIC Educational Resources Information Center

Burton, Kelley

2011-01-01

Authentic assessment tasks enhance engagement, retention and the aspirations of students. This paper explores the discipline-generic features of authentic assessment, which reflect what students need to achieve in the real world. Some assessment tasks are more authentic than others and this paper designs a proposed framework supported by the…

Actions for productivity improvement in crew training

NASA Technical Reports Server (NTRS)

Miller, G. E.

1985-01-01

Improvement of the productivity of astronaut crew instructors in the Space Shuttle program and beyond is proposed. It is suggested that instructor certification plans should be established to shorten the time required for trainers to develop their skills and improve their ability to convey those skills. Members of the training cadre should be thoroughly cross trained in their task. This provides better understanding of the overall task and greater flexibility in instructor utilization. Improved facility access will give instructors the benefit of practical application experience. Former crews should be integrated into the training of upcoming crews to bridge some of the gap between simulated conditions and the real world. The information contained in lengthy and complex training manuals can be presented more clearly and efficiently as computer lessons. The illustration, animation and interactive capabilities of the computer combine an effective means of explanation.

A Human Proximity Operations System test case validation approach

NASA Astrophysics Data System (ADS)

Huber, Justin; Straub, Jeremy

A Human Proximity Operations System (HPOS) poses numerous risks in a real world environment. These risks range from mundane tasks such as avoiding walls and fixed obstacles to the critical need to keep people and processes safe in the context of the HPOS's situation-specific decision making. Validating the performance of an HPOS, which must operate in a real-world environment, is an ill posed problem due to the complexity that is introduced by erratic (non-computer) actors. In order to prove the HPOS's usefulness, test cases must be generated to simulate possible actions of these actors, so the HPOS can be shown to be able perform safely in environments where it will be operated. The HPOS must demonstrate its ability to be as safe as a human, across a wide range of foreseeable circumstances. This paper evaluates the use of test cases to validate HPOS performance and utility. It considers an HPOS's safe performance in the context of a common human activity, moving through a crowded corridor, and extrapolates (based on this) to the suitability of using test cases for AI validation in other areas of prospective application.

Non-stationary noise estimation using dictionary learning and Gaussian mixture models

NASA Astrophysics Data System (ADS)

Hughes, James M.; Rockmore, Daniel N.; Wang, Yang

2014-02-01

Stationarity of the noise distribution is a common assumption in image processing. This assumption greatly simplifies denoising estimators and other model parameters and consequently assuming stationarity is often a matter of convenience rather than an accurate model of noise characteristics. The problematic nature of this assumption is exacerbated in real-world contexts, where noise is often highly non-stationary and can possess time- and space-varying characteristics. Regardless of model complexity, estimating the parameters of noise dis- tributions in digital images is a difficult task, and estimates are often based on heuristic assumptions. Recently, sparse Bayesian dictionary learning methods were shown to produce accurate estimates of the level of additive white Gaussian noise in images with minimal assumptions. We show that a similar model is capable of accu- rately modeling certain kinds of non-stationary noise processes, allowing for space-varying noise in images to be estimated, detected, and removed. We apply this modeling concept to several types of non-stationary noise and demonstrate the model's effectiveness on real-world problems, including denoising and segmentation of images according to noise characteristics, which has applications in image forensics.

Rational BRDF.

PubMed

Pacanowski, Romain; Salazar Celis, Oliver; Schlick, Christophe; Granier, Xavier; Poulin, Pierre; Cuyt, Annie

2012-11-01

Over the last two decades, much effort has been devoted to accurately measuring Bidirectional Reflectance Distribution Functions (BRDFs) of real-world materials and to use efficiently the resulting data for rendering. Because of their large size, it is difficult to use directly measured BRDFs for real-time applications, and fitting the most sophisticated analytical BRDF models is still a complex task. In this paper, we introduce Rational BRDF, a general-purpose and efficient representation for arbitrary BRDFs, based on Rational Functions (RFs). Using an adapted parametrization, we demonstrate how Rational BRDFs offer 1) a more compact and efficient representation using low-degree RFs, 2) an accurate fitting of measured materials with guaranteed control of the residual error, and 3) efficient importance sampling by applying the same fitting process to determine the inverse of the Cumulative Distribution Function (CDF) generated from the BRDF for use in Monte-Carlo rendering.

Mathematical concepts for modeling human behavior in complex man-machine systems

NASA Technical Reports Server (NTRS)

Johannsen, G.; Rouse, W. B.

1979-01-01

Many human behavior (e.g., manual control) models have been found to be inadequate for describing processes in certain real complex man-machine systems. An attempt is made to find a way to overcome this problem by examining the range of applicability of existing mathematical models with respect to the hierarchy of human activities in real complex tasks. Automobile driving is chosen as a baseline scenario, and a hierarchy of human activities is derived by analyzing this task in general terms. A structural description leads to a block diagram and a time-sharing computer analogy.

Markov logic network based complex event detection under uncertainty

NASA Astrophysics Data System (ADS)

Lu, Jingyang; Jia, Bin; Chen, Genshe; Chen, Hua-mei; Sullivan, Nichole; Pham, Khanh; Blasch, Erik

2018-05-01

In a cognitive reasoning system, the four-stage Observe-Orient-Decision-Act (OODA) reasoning loop is of interest. The OODA loop is essential for the situational awareness especially in heterogeneous data fusion. Cognitive reasoning for making decisions can take advantage of different formats of information such as symbolic observations, various real-world sensor readings, or the relationship between intelligent modalities. Markov Logic Network (MLN) provides mathematically sound technique in presenting and fusing data at multiple levels of abstraction, and across multiple intelligent sensors to conduct complex decision-making tasks. In this paper, a scenario about vehicle interaction is investigated, in which uncertainty is taken into consideration as no systematic approaches can perfectly characterize the complex event scenario. MLNs are applied to the terrestrial domain where the dynamic features and relationships among vehicles are captured through multiple sensors and information sources regarding the data uncertainty.

Visual analysis and exploration of complex corporate shareholder networks

NASA Astrophysics Data System (ADS)

Tekušová, Tatiana; Kohlhammer, Jörn

2008-01-01

The analysis of large corporate shareholder network structures is an important task in corporate governance, in financing, and in financial investment domains. In a modern economy, large structures of cross-corporation, cross-border shareholder relationships exist, forming complex networks. These networks are often difficult to analyze with traditional approaches. An efficient visualization of the networks helps to reveal the interdependent shareholding formations and the controlling patterns. In this paper, we propose an effective visualization tool that supports the financial analyst in understanding complex shareholding networks. We develop an interactive visual analysis system by combining state-of-the-art visualization technologies with economic analysis methods. Our system is capable to reveal patterns in large corporate shareholder networks, allows the visual identification of the ultimate shareholders, and supports the visual analysis of integrated cash flow and control rights. We apply our system on an extensive real-world database of shareholder relationships, showing its usefulness for effective visual analysis.

Exploratory Decision-Making as a Function of Lifelong Experience, Not Cognitive Decline

PubMed Central

2016-01-01

Older adults perform worse than younger adults in some complex decision-making scenarios, which is commonly attributed to age-related declines in striatal and frontostriatal processing. Recently, this popular account has been challenged by work that considered how older adults’ performance may differ as a function of greater knowledge and experience, and by work showing that, in some cases, older adults outperform younger adults in complex decision-making tasks. In light of this controversy, we examined the performance of older and younger adults in an exploratory choice task that is amenable to model-based analyses and ostensibly not reliant on prior knowledge. Exploration is a critical aspect of decision-making poorly understood across the life span. Across 2 experiments, we addressed (a) how older and younger adults differ in exploratory choice and (b) to what extent observed differences reflect processing capacity declines. Model-based analyses suggested that the strategies used by the 2 groups were qualitatively different, resulting in relatively worse performance for older adults in 1 decision-making environment but equal performance in another. Little evidence was found that differences in processing capacity drove performance differences. Rather the results suggested that older adults’ performance might result from applying a strategy that may have been shaped by their wealth of real-word decision-making experience. While this strategy is likely to be effective in the real world, it is ill suited to some decision environments. These results underscore the importance of taking into account effects of experience in aging studies, even for tasks that do not obviously tap past experiences. PMID:26726916

USMC Contingency Contracting Force: An Analysis of Transient Officers in a Rapidly Changing Acquisition Environment

DTIC Science & Technology

2016-06-01

and skills needed to manage the department’s acquisition system” (2008, p. 268). Relating back to the CCF, an overpopulation of lieutenant colonels...an individual task. Officers should subsequently be deployed in real world operations based upon the levels of technical competency they have...therefore, officers that transfer to the ECP need to be engaged in real- world operations as soon as possible to retain the skills obtained during

Making the Most of Modeling Tasks

ERIC Educational Resources Information Center

Wernet, Jamie L.; Lawrence, Kevin A.; Gilbertson, Nicholas J.

2015-01-01

While there is disagreement among mathematics educators about some aspects of its meaning, mathematical modeling generally involves taking a real-world scenario and translating it into the mathematical world (Niss, Blum, and Galbraith 2007). The complete modeling process involves describing situations posed in problems with mathematical concepts,…

Seven Billion People: Fostering Productive Struggle

ERIC Educational Resources Information Center

Murawska, Jaclyn M.

2018-01-01

How can a cognitively demanding real-world task such as the Seven Billion People problem promote productive struggle "and" help shape students' mathematical dispositions? Driving home from school one evening, Jaclyn Murawska heard a commentator on the radio announce three statements: (1) experts had determined that the world population…

Language, Thought, and Real Nouns

ERIC Educational Resources Information Center

Barner, David; Inagaki, Shunji; Li, Peggy

2009-01-01

We test the claim that acquiring a mass-count language, like English, causes speakers to think differently about entities in the world, relative to speakers of classifier languages like Japanese. We use three tasks to assess this claim: object-substance rating, quantity judgment, and word extension. Using the first two tasks, we present evidence…

Decision Making and Learning while Taking Sequential Risks

ERIC Educational Resources Information Center

Pleskac, Timothy J.

2008-01-01

A sequential risk-taking paradigm used to identify real-world risk takers invokes both learning and decision processes. This article expands the paradigm to a larger class of tasks with different stochastic environments and different learning requirements. Generalizing a Bayesian sequential risk-taking model to the larger set of tasks clarifies…

Task complexity modulates pilot electroencephalographic activity during real flights.

PubMed

Di Stasi, Leandro L; Diaz-Piedra, Carolina; Suárez, Juan; McCamy, Michael B; Martinez-Conde, Susana; Roca-Dorda, Joaquín; Catena, Andrés

2015-07-01

Most research connecting task performance and neural activity to date has been conducted in laboratory conditions. Thus, field studies remain scarce, especially in extreme conditions such as during real flights. Here, we investigated the effects of flight procedures of varied complexity on the in-flight EEG activity of military helicopter pilots. Flight procedural complexity modulated the EEG power spectrum: highly demanding procedures (i.e., takeoff and landing) were associated with higher EEG power in the higher frequency bands, whereas less demanding procedures (i.e., flight exercises) were associated with lower EEG power over the same frequency bands. These results suggest that EEG recordings may help to evaluate an operator's cognitive performance in challenging real-life scenarios, and thus could aid in the prevention of catastrophic events. © 2015 Society for Psychophysiological Research.

Recent trends in robot-assisted therapy environments to improve real-life functional performance after stroke.

PubMed

Johnson, Michelle J

2006-12-18

Upper and lower limb robotic tools for neuro-rehabilitation are effective in reducing motor impairment but they are limited in their ability to improve real world function. There is a need to improve functional outcomes after robot-assisted therapy. Improvements in the effectiveness of these environments may be achieved by incorporating into their design and control strategies important elements key to inducing motor learning and cerebral plasticity such as mass-practice, feedback, task-engagement, and complex problem solving. This special issue presents nine articles. Novel strategies covered in this issue encourage more natural movements through the use of virtual reality and real objects and faster motor learning through the use of error feedback to guide acquisition of natural movements that are salient to real activities. In addition, several articles describe novel systems and techniques that use of custom and commercial games combined with new low-cost robot systems and a humanoid robot to embody the " supervisory presence" of the therapy as possible solutions to exercise compliance in under-supervised environments such as the home.

Recent trends in robot-assisted therapy environments to improve real-life functional performance after stroke

PubMed Central

Johnson, Michelle J

2006-01-01

Upper and lower limb robotic tools for neuro-rehabilitation are effective in reducing motor impairment but they are limited in their ability to improve real world function. There is a need to improve functional outcomes after robot-assisted therapy. Improvements in the effectiveness of these environments may be achieved by incorporating into their design and control strategies important elements key to inducing motor learning and cerebral plasticity such as mass-practice, feedback, task-engagement, and complex problem solving. This special issue presents nine articles. Novel strategies covered in this issue encourage more natural movements through the use of virtual reality and real objects and faster motor learning through the use of error feedback to guide acquisition of natural movements that are salient to real activities. In addition, several articles describe novel systems and techniques that use of custom and commercial games combined with new low-cost robot systems and a humanoid robot to embody the " supervisory presence" of the therapy as possible solutions to exercise compliance in under-supervised environments such as the home. PMID:17176474

Energy-Efficient Neuromorphic Classifiers.

PubMed

Martí, Daniel; Rigotti, Mattia; Seok, Mingoo; Fusi, Stefano

2016-10-01

Neuromorphic engineering combines the architectural and computational principles of systems neuroscience with semiconductor electronics, with the aim of building efficient and compact devices that mimic the synaptic and neural machinery of the brain. The energy consumptions promised by neuromorphic engineering are extremely low, comparable to those of the nervous system. Until now, however, the neuromorphic approach has been restricted to relatively simple circuits and specialized functions, thereby obfuscating a direct comparison of their energy consumption to that used by conventional von Neumann digital machines solving real-world tasks. Here we show that a recent technology developed by IBM can be leveraged to realize neuromorphic circuits that operate as classifiers of complex real-world stimuli. Specifically, we provide a set of general prescriptions to enable the practical implementation of neural architectures that compete with state-of-the-art classifiers. We also show that the energy consumption of these architectures, realized on the IBM chip, is typically two or more orders of magnitude lower than that of conventional digital machines implementing classifiers with comparable performance. Moreover, the spike-based dynamics display a trade-off between integration time and accuracy, which naturally translates into algorithms that can be flexibly deployed for either fast and approximate classifications, or more accurate classifications at the mere expense of longer running times and higher energy costs. This work finally proves that the neuromorphic approach can be efficiently used in real-world applications and has significant advantages over conventional digital devices when energy consumption is considered.

Ranking in evolving complex networks

NASA Astrophysics Data System (ADS)

Liao, Hao; Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng; Zhou, Ming-Yang

2017-05-01

Complex networks have emerged as a simple yet powerful framework to represent and analyze a wide range of complex systems. The problem of ranking the nodes and the edges in complex networks is critical for a broad range of real-world problems because it affects how we access online information and products, how success and talent are evaluated in human activities, and how scarce resources are allocated by companies and policymakers, among others. This calls for a deep understanding of how existing ranking algorithms perform, and which are their possible biases that may impair their effectiveness. Many popular ranking algorithms (such as Google's PageRank) are static in nature and, as a consequence, they exhibit important shortcomings when applied to real networks that rapidly evolve in time. At the same time, recent advances in the understanding and modeling of evolving networks have enabled the development of a wide and diverse range of ranking algorithms that take the temporal dimension into account. The aim of this review is to survey the existing ranking algorithms, both static and time-aware, and their applications to evolving networks. We emphasize both the impact of network evolution on well-established static algorithms and the benefits from including the temporal dimension for tasks such as prediction of network traffic, prediction of future links, and identification of significant nodes.

The way to uncover community structure with core and diversity

NASA Astrophysics Data System (ADS)

Chang, Y. F.; Han, S. K.; Wang, X. D.

2018-07-01

Communities are ubiquitous in nature and society. Individuals that share common properties often self-organize to form communities. Avoiding the shortages of computation complexity, pre-given information and unstable results in different run, in this paper, we propose a simple and efficient method to deepen our understanding of the emergence and diversity of communities in complex systems. By introducing the rational random selection, our method reveals the hidden deterministic and normal diverse community states of community structure. To demonstrate this method, we test it with real-world systems. The results show that our method could not only detect community structure with high sensitivity and reliability, but also provide instructional information about the hidden deterministic community world and the real normal diverse community world by giving out the core-community, the real-community, the tide and the diversity. Thizs is of paramount importance in understanding, predicting, and controlling a variety of collective behaviors in complex systems.

Running Memory for Clinical Handoffs: A Look at Active and Passive Processing.

PubMed

Anderson-Montoya, Brittany L; Scerbo, Mark W; Ramirez, Dana E; Hubbard, Thomas W

2017-05-01

The goal of the present study was to examine the effects of domain-relevant expertise on running memory and the ability to process handoffs of information. In addition, the role of active or passive processing was examined. Currently, there is little research that addresses how individuals with different levels of expertise process information in running memory when the information is needed to perform a real-world task. Three groups of participants differing in their level of clinical expertise (novice, intermediate, and expert) performed an abstract running memory span task and two tasks resembling real-world activities, a clinical handoff task and an air traffic control (ATC) handoff task. For all tasks, list length and the amount of information to be recalled were manipulated. Regarding processing strategy, all participants used passive processing for the running memory span and ATC tasks. The novices also used passive processing for the clinical task. The experts, however, appeared to use more active processing, and the intermediates fell in between. Overall, the results indicated that individuals with clinical expertise and a developed mental model rely more on active processing of incoming information for the clinical task while individuals with little or no knowledge rely on passive processing. The results have implications about how training should be developed to aid less experienced personnel identify what information should be included in a handoff and what should not.

A Temporal Pattern Mining Approach for Classifying Electronic Health Record Data

PubMed Central

Batal, Iyad; Valizadegan, Hamed; Cooper, Gregory F.; Hauskrecht, Milos

2013-01-01

We study the problem of learning classification models from complex multivariate temporal data encountered in electronic health record systems. The challenge is to define a good set of features that are able to represent well the temporal aspect of the data. Our method relies on temporal abstractions and temporal pattern mining to extract the classification features. Temporal pattern mining usually returns a large number of temporal patterns, most of which may be irrelevant to the classification task. To address this problem, we present the Minimal Predictive Temporal Patterns framework to generate a small set of predictive and non-spurious patterns. We apply our approach to the real-world clinical task of predicting patients who are at risk of developing heparin induced thrombocytopenia. The results demonstrate the benefit of our approach in efficiently learning accurate classifiers, which is a key step for developing intelligent clinical monitoring systems. PMID:25309815

Mind over motor mapping: Driver response to changing vehicle dynamics.

PubMed

Bruno, Jennifer L; Baker, Joseph M; Gundran, Andrew; Harbott, Lene K; Stuart, Zachary; Piccirilli, Aaron M; Hosseini, S M Hadi; Gerdes, J Christian; Reiss, Allan L

2018-06-08

Improvements in vehicle safety require understanding of the neural systems that support the complex, dynamic task of real-world driving. We used functional near infrared spectroscopy (fNIRS) and pupilometry to quantify cortical and physiological responses during a realistic, simulated driving task in which vehicle dynamics were manipulated. Our results elucidate compensatory changes in driver behavior in response to changes in vehicle handling. We also describe associated neural and physiological responses under different levels of mental workload. The increased cortical activation we observed during the late phase of the experiment may indicate motor learning in prefrontal-parietal networks. Finally, relationships among cortical activation, steering control, and individual personality traits suggest that individual brain states and traits may be useful in predicting a driver's response to changes in vehicle dynamics. Results such as these will be useful for informing the design of automated safety systems that facilitate safe and supportive driver-car communication. © 2018 Wiley Periodicals, Inc.

Tasks for Easily Modifiable Virtual Environments

ERIC Educational Resources Information Center

Swier, Robert

2014-01-01

Recent studies of learner interaction in virtual worlds have tended to select basic tasks involving open-ended communication. There is evidence that such tasks are supportive of language acquisition, however it may also be beneficial to consider more complex tasks. Research in task-based learning has identified features such as non-linguistic…

The ground truth about metadata and community detection in networks.

PubMed

Peel, Leto; Larremore, Daniel B; Clauset, Aaron

2017-05-01

Across many scientific domains, there is a common need to automatically extract a simplified view or coarse-graining of how a complex system's components interact. This general task is called community detection in networks and is analogous to searching for clusters in independent vector data. It is common to evaluate the performance of community detection algorithms by their ability to find so-called ground truth communities. This works well in synthetic networks with planted communities because these networks' links are formed explicitly based on those known communities. However, there are no planted communities in real-world networks. Instead, it is standard practice to treat some observed discrete-valued node attributes, or metadata, as ground truth. We show that metadata are not the same as ground truth and that treating them as such induces severe theoretical and practical problems. We prove that no algorithm can uniquely solve community detection, and we prove a general No Free Lunch theorem for community detection, which implies that there can be no algorithm that is optimal for all possible community detection tasks. However, community detection remains a powerful tool and node metadata still have value, so a careful exploration of their relationship with network structure can yield insights of genuine worth. We illustrate this point by introducing two statistical techniques that can quantify the relationship between metadata and community structure for a broad class of models. We demonstrate these techniques using both synthetic and real-world networks, and for multiple types of metadata and community structures.

Study on the Effectiveness of Virtual Reality Game-Based Training on Balance and Functional Performance in Individuals with Paraplegia

PubMed Central

Khurana, Meetika; Walia, Shefali

2017-01-01

Objective: To determine whether there is any difference between virtual reality game–based balance training and real-world task-specific balance training in improving sitting balance and functional performance in individuals with paraplegia. Methods: The study was a pre test–post test experimental design. There were 30 participants (28 males, 2 females) with traumatic spinal cord injury randomly assigned to 2 groups (group A and B). The levels of spinal injury of the participants were between T6 and T12. The virtual reality game–based balance training and real-world task-specific balance training were used as interventions in groups A and B, respectively. The total duration of the intervention was 4 weeks, with a frequency of 5 times a week; each training session lasted 45 minutes. The outcome measures were modified Functional Reach Test (mFRT), t-shirt test, and the self-care component of the Spinal Cord Independence Measure–III (SCIM-III). Results: There was a significant difference for time (p = .001) and Time × Group effect (p = .001) in mFRT scores, group effect (p = .05) in t-shirt test scores, and time effect (p = .001) in the self-care component of SCIM-III. Conclusions: Virtual reality game–based training is better in improving balance and functional performance in individuals with paraplegia than real-world task-specific balance training. PMID:29339902

Study on the Effectiveness of Virtual Reality Game-Based Training on Balance and Functional Performance in Individuals with Paraplegia.

PubMed

Khurana, Meetika; Walia, Shefali; Noohu, Majumi M

2017-01-01

Objective: To determine whether there is any difference between virtual reality game-based balance training and real-world task-specific balance training in improving sitting balance and functional performance in individuals with paraplegia. Methods: The study was a pre test-post test experimental design. There were 30 participants (28 males, 2 females) with traumatic spinal cord injury randomly assigned to 2 groups (group A and B). The levels of spinal injury of the participants were between T6 and T12. The virtual reality game-based balance training and real-world task-specific balance training were used as interventions in groups A and B, respectively. The total duration of the intervention was 4 weeks, with a frequency of 5 times a week; each training session lasted 45 minutes. The outcome measures were modified Functional Reach Test (mFRT), t-shirt test, and the self-care component of the Spinal Cord Independence Measure-III (SCIM-III). Results: There was a significant difference for time ( p = .001) and Time × Group effect ( p = .001) in mFRT scores, group effect ( p = .05) in t-shirt test scores, and time effect ( p = .001) in the self-care component of SCIM-III. Conclusions: Virtual reality game-based training is better in improving balance and functional performance in individuals with paraplegia than real-world task-specific balance training.

Teaching problem solving using non-routine tasks

NASA Astrophysics Data System (ADS)

Chong, Maureen Siew Fang; Shahrill, Masitah; Putri, Ratu Ilma Indra; Zulkardi

2018-04-01

Non-routine problems are related to real-life context and require some realistic considerations and real-world knowledge in order to resolve them. This study examines several activity tasks incorporated with non-routine problems through the use of an emerging mathematics framework, at two junior colleges in Brunei Darussalam. The three sampled teachers in this study assisted in selecting the topics and the lesson plan designs. They also recommended the development of the four activity tasks: incorporating the use of technology; simulation of a reality television show; designing real-life sized car park spaces for the school; and a classroom activity to design a real-life sized dustpan. Data collected from all four of the activity tasks were analyzed based on the students' group work. The findings revealed that the most effective activity task in teaching problem solving was to design a real-life sized car park. This was because the use of real data gave students the opportunity to explore, gather information and give or receive feedback on the effect of their reasons and proposed solutions. The second most effective activity task was incorporating the use of technology as it enhanced the students' understanding of the concepts learnt in the classroom. This was followed by the classroom activity that used real data as it allowed students to work and assess the results mathematically. The simulation of a television show was found to be the least effective since it was viewed as not sufficiently challenging to the students.

Change deafness for real spatialized environmental scenes.

PubMed

Gaston, Jeremy; Dickerson, Kelly; Hipp, Daniel; Gerhardstein, Peter

2017-01-01

The everyday auditory environment is complex and dynamic; often, multiple sounds co-occur and compete for a listener's cognitive resources. 'Change deafness', framed as the auditory analog to the well-documented phenomenon of 'change blindness', describes the finding that changes presented within complex environments are often missed. The present study examines a number of stimulus factors that may influence change deafness under real-world listening conditions. Specifically, an AX (same-different) discrimination task was used to examine the effects of both spatial separation over a loudspeaker array and the type of change (sound source additions and removals) on discrimination of changes embedded in complex backgrounds. Results using signal detection theory and accuracy analyses indicated that, under most conditions, errors were significantly reduced for spatially distributed relative to non-spatial scenes. A second goal of the present study was to evaluate a possible link between memory for scene contents and change discrimination. Memory was evaluated by presenting a cued recall test following each trial of the discrimination task. Results using signal detection theory and accuracy analyses indicated that recall ability was similar in terms of accuracy, but there were reductions in sensitivity compared to previous reports. Finally, the present study used a large and representative sample of outdoor, urban, and environmental sounds, presented in unique combinations of nearly 1000 trials per participant. This enabled the exploration of the relationship between change perception and the perceptual similarity between change targets and background scene sounds. These (post hoc) analyses suggest both a categorical and a stimulus-level relationship between scene similarity and the magnitude of change errors.

Real-time, haptics-enabled simulator for probing ex vivo liver tissue.

PubMed

Lister, Kevin; Gao, Zhan; Desai, Jaydev P

2009-01-01

The advent of complex surgical procedures has driven the need for realistic surgical training simulators. Comprehensive simulators that provide realistic visual and haptic feedback during surgical tasks are required to familiarize surgeons with the procedures they are to perform. Complex organ geometry inherent to biological tissues and intricate material properties drive the need for finite element methods to assure accurate tissue displacement and force calculations. Advances in real-time finite element methods have not reached the state where they are applicable to soft tissue surgical simulation. Therefore a real-time, haptics-enabled simulator for probing of soft tissue has been developed which utilizes preprocessed finite element data (derived from accurate constitutive model of the soft-tissue obtained from carefully collected experimental data) to accurately replicate the probing task in real-time.

Towards multi-platform software architecture for Collaborative Teleoperation

NASA Astrophysics Data System (ADS)

Domingues, Christophe; Otmane, Samir; Davesne, Frederic; Mallem, Malik

2009-03-01

Augmented Reality (AR) can provide to a Human Operator (HO) a real help in achieving complex tasks, such as remote control of robots and cooperative teleassistance. Using appropriate augmentations, the HO can interact faster, safer and easier with the remote real world. In this paper, we present an extension of an existing distributed software and network architecture for collaborative teleoperation based on networked human-scaled mixed reality and mobile platform. The first teleoperation system was composed by a VR application and a Web application. However the 2 systems cannot be used together and it is impossible to control a distant robot simultaneously. Our goal is to update the teleoperation system to permit a heterogeneous collaborative teleoperation between the 2 platforms. An important feature of this interface is based on the use of different Virtual Reality platforms and different Mobile platforms to control one or many robots.

Filtering Data Based on Human-Inspired Forgetting.

PubMed

Freedman, S T; Adams, J A

2011-12-01

Robots are frequently presented with vast arrays of diverse data. Unfortunately, perfect memory and recall provides a mixed blessing. While flawless recollection of episodic data allows increased reasoning, photographic memory can hinder a robot's ability to operate in real-time dynamic environments. Human-inspired forgetting methods may enable robotic systems to rid themselves of out-dated, irrelevant, and erroneous data. This paper presents the use of human-inspired forgetting to act as a filter, removing unnecessary, erroneous, and out-of-date information. The novel ActSimple forgetting algorithm has been developed specifically to provide effective forgetting capabilities to robotic systems. This paper presents the ActSimple algorithm and how it was optimized and tested in a WiFi signal strength estimation task. The results generated by real-world testing suggest that human-inspired forgetting is an effective means of improving the ability of mobile robots to move and operate within complex and dynamic environments.

Towards multi-platform software architecture for Collaborative Teleoperation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Domingues, Christophe; Otmane, Samir; Davesne, Frederic

2009-03-05

Augmented Reality (AR) can provide to a Human Operator (HO) a real help in achieving complex tasks, such as remote control of robots and cooperative teleassistance. Using appropriate augmentations, the HO can interact faster, safer and easier with the remote real world. In this paper, we present an extension of an existing distributed software and network architecture for collaborative teleoperation based on networked human-scaled mixed reality and mobile platform. The first teleoperation system was composed by a VR application and a Web application. However the 2 systems cannot be used together and it is impossible to control a distant robotmore » simultaneously. Our goal is to update the teleoperation system to permit a heterogeneous collaborative teleoperation between the 2 platforms. An important feature of this interface is based on the use of different Virtual Reality platforms and different Mobile platforms to control one or many robots.« less

Evaluating Fifth- and Sixth-Grade Students' Expository Writing: Task Development, Scoring, and Psychometric Issues

ERIC Educational Resources Information Center

Kulikowich, Jonna M.; Mason, Linda H.; Brown, Scott W.

2008-01-01

Drawing from multiple theoretical frameworks representing cognitive and educational psychology, we present a writing task and scoring system for measurement of students' informative writing. Participants in this study were 72 fifth- and sixth-grade students who wrote compositions describing real-world problems and how mathematics, science, and…

Performance Tasks and the Pedagogy of Broadway

ERIC Educational Resources Information Center

Chun, Marc

2012-01-01

If educators want students to practice and prepare for challenges they might eventually face, there are a number of useful strategies to connect academic learning to the "real world." One is to ask students to complete what are variously called "performance tasks," "case studies," "simulations," or "project- or problem-based learning units."…

Preserving with Prisms: Producing Nets

ERIC Educational Resources Information Center

Prummer, Kathy E.; Amador, Julie M.; Wallin, Abraham J.

2016-01-01

Two mathematics teachers in a small rural school decided to create a task that would engage seventh graders. The goal of the real-world activity was to help students develop geometric and spatial reasoning and to support their understanding of volume of rectangular prisms. The impetus for the task came from the teachers' desire to engage students…

An Open-Sourced and Interactive Ebook Development Program for Minority Languages

ERIC Educational Resources Information Center

Sheepy, Emily; Sundberg, Ross; Laurie, Anne

2017-01-01

According to Long (2014), genuine task-based pedagogy is centered around the real-world activities that learners need to complete using the target language. We are developing the OurStories mobile application to support learners and instructors of minority languages in the development of personally relevant, task-based learning resources. The…

The Implementation of Service-Learning in Graduate Instructional Design Coursework

ERIC Educational Resources Information Center

Stefaniak, Jill E.

2015-01-01

This paper describes the design of service-learning experiences with a graduate-level instructional design course. Service-learning provides students with real-life experiences in a situated-learning environment. Students were tasked with working on an instructional design project in a real-world setting to gain consultative experience. This paper…

Algorithmic Management for Improving Collective Productivity in Crowdsourcing.

PubMed

Yu, Han; Miao, Chunyan; Chen, Yiqiang; Fauvel, Simon; Li, Xiaoming; Lesser, Victor R

2017-10-02

Crowdsourcing systems are complex not only because of the huge number of potential strategies for assigning workers to tasks, but also due to the dynamic characteristics associated with workers. Maximizing social welfare in such situations is known to be NP-hard. To address these fundamental challenges, we propose the surprise-minimization-value-maximization (SMVM) approach. By analysing typical crowdsourcing system dynamics, we established a simple and novel worker desirability index (WDI) jointly considering the effect of each worker's reputation, workload and motivation to work on collective productivity. Through evaluating workers' WDI values, SMVM influences individual workers in real time about courses of action which can benefit the workers and lead to high collective productivity. Solutions can be produced in polynomial time and are proven to be asymptotically bounded by a theoretical optimal solution. High resolution simulations based on a real-world dataset demonstrate that SMVM significantly outperforms state-of-the-art approaches. A large-scale 3-year empirical study involving 1,144 participants in over 9,000 sessions shows that SMVM outperforms human task delegation decisions over 80% of the time under common workload conditions. The approach and results can help engineer highly scalable data-driven algorithmic management decision support systems for crowdsourcing.

Real-world spatial regularities affect visual working memory for objects.

PubMed

Kaiser, Daniel; Stein, Timo; Peelen, Marius V

2015-12-01

Traditional memory research has focused on measuring and modeling the capacity of visual working memory for simple stimuli such as geometric shapes or colored disks. Although these studies have provided important insights, it is unclear how their findings apply to memory for more naturalistic stimuli. An important aspect of real-world scenes is that they contain a high degree of regularity: For instance, lamps appear above tables, not below them. In the present study, we tested whether such real-world spatial regularities affect working memory capacity for individual objects. Using a delayed change-detection task with concurrent verbal suppression, we found enhanced visual working memory performance for objects positioned according to real-world regularities, as compared to irregularly positioned objects. This effect was specific to upright stimuli, indicating that it did not reflect low-level grouping, because low-level grouping would be expected to equally affect memory for upright and inverted displays. These results suggest that objects can be held in visual working memory more efficiently when they are positioned according to frequently experienced real-world regularities. We interpret this effect as the grouping of single objects into larger representational units.

Working memory is not fixed-capacity: More active storage capacity for real-world objects than for simple stimuli

PubMed Central

Brady, Timothy F.; Störmer, Viola S.; Alvarez, George A.

2016-01-01

Visual working memory is the cognitive system that holds visual information active to make it resistant to interference from new perceptual input. Information about simple stimuli—colors and orientations—is encoded into working memory rapidly: In under 100 ms, working memory ‟fills up,” revealing a stark capacity limit. However, for real-world objects, the same behavioral limits do not hold: With increasing encoding time, people store more real-world objects and do so with more detail. This boost in performance for real-world objects is generally assumed to reflect the use of a separate episodic long-term memory system, rather than working memory. Here we show that this behavioral increase in capacity with real-world objects is not solely due to the use of separate episodic long-term memory systems. In particular, we show that this increase is a result of active storage in working memory, as shown by directly measuring neural activity during the delay period of a working memory task using EEG. These data challenge fixed-capacity working memory models and demonstrate that working memory and its capacity limitations are dependent upon our existing knowledge. PMID:27325767

Working memory is not fixed-capacity: More active storage capacity for real-world objects than for simple stimuli.

PubMed

Brady, Timothy F; Störmer, Viola S; Alvarez, George A

2016-07-05

Visual working memory is the cognitive system that holds visual information active to make it resistant to interference from new perceptual input. Information about simple stimuli-colors and orientations-is encoded into working memory rapidly: In under 100 ms, working memory ‟fills up," revealing a stark capacity limit. However, for real-world objects, the same behavioral limits do not hold: With increasing encoding time, people store more real-world objects and do so with more detail. This boost in performance for real-world objects is generally assumed to reflect the use of a separate episodic long-term memory system, rather than working memory. Here we show that this behavioral increase in capacity with real-world objects is not solely due to the use of separate episodic long-term memory systems. In particular, we show that this increase is a result of active storage in working memory, as shown by directly measuring neural activity during the delay period of a working memory task using EEG. These data challenge fixed-capacity working memory models and demonstrate that working memory and its capacity limitations are dependent upon our existing knowledge.

Stress Training and Simulator Complexity: Why Sometimes More Is Less

ERIC Educational Resources Information Center

Tichon, Jennifer G.; Wallis, Guy M.

2010-01-01

Through repeated practice under conditions similar to those in real-world settings, simulator training prepares an individual to maintain effective performance under stressful work conditions. Interfaces offering high fidelity and immersion can more closely reproduce real-world experiences and are generally believed to result in better learning…

Real-time monitoring of clinical processes using complex event processing and transition systems.

PubMed

Meinecke, Sebastian

2014-01-01

Dependencies between tasks in clinical processes are often complex and error-prone. Our aim is to describe a new approach for the automatic derivation of clinical events identified via the behaviour of IT systems using Complex Event Processing. Furthermore we map these events on transition systems to monitor crucial clinical processes in real-time for preventing and detecting erroneous situations.

A study of navigation in virtual space

NASA Technical Reports Server (NTRS)

Darken, Rudy; Sibert, John L.; Shumaker, Randy

1994-01-01

In the physical world, man has developed efficient methods for navigation and orientation. These methods are dependent on the high-fidelity stimuli presented by the environment. When placed in a virtual world which cannot offer stimuli of the same quality due to computing constraints and immature technology, tasks requiring the maintenance of position and orientation knowledge become laborious. In this paper, we present a representative set of techniques based on principles of navigation derived from real world analogs including human and avian navigation behavior and cartography. A preliminary classification of virtual worlds is presented based on the size of the world, the density of objects in the world, and the level of activity taking place in the world. We also summarize an informal study we performed to determine how the tools influenced the subjects' navigation strategies and behavior. We conclude that principles extracted from real world navigation aids such as maps can be seen to apply in virtual environments.

Comparison of oral surgery task performance in a virtual reality surgical simulator and an animal model using objective measures.

PubMed

Ioannou, Ioanna; Kazmierczak, Edmund; Stern, Linda

2015-01-01

The use of virtual reality (VR) simulation for surgical training has gathered much interest in recent years. Despite increasing popularity and usage, limited work has been carried out in the use of automated objective measures to quantify the extent to which performance in a simulator resembles performance in the operating theatre, and the effects of simulator training on real world performance. To this end, we present a study exploring the effects of VR training on the performance of dentistry students learning a novel oral surgery task. We compare the performance of trainees in a VR simulator and in a physical setting involving ovine jaws, using a range of automated metrics derived by motion analysis. Our results suggest that simulator training improved the motion economy of trainees without adverse effects on task outcome. Comparison of surgical technique on the simulator with the ovine setting indicates that simulator technique is similar, but not identical to real world technique.

Survey of Approaches to Generate Realistic Synthetic Graphs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, Seung-Hwan; Lee, Sangkeun; Powers, Sarah S

A graph is a flexible data structure that can represent relationships between entities. As with other data analysis tasks, the use of realistic graphs is critical to obtaining valid research results. Unfortunately, using the actual ("real-world") graphs for research and new algorithm development is difficult due to the presence of sensitive information in the data or due to the scale of data. This results in practitioners developing algorithms and systems that employ synthetic graphs instead of real-world graphs. Generating realistic synthetic graphs that provide reliable statistical confidence to algorithmic analysis and system evaluation involves addressing technical hurdles in a broadmore » set of areas. This report surveys the state of the art in approaches to generate realistic graphs that are derived from fitted graph models on real-world graphs.« less

Motion artifact removal in FNIR spectroscopy for real-world applications

NASA Astrophysics Data System (ADS)

Devaraj, Ajit; Izzetoglu, Meltem; Izzetoglu, Kurtulus; Bunce, Scott C.; Li, Connie Y.; Onaral, Banu

2004-12-01

Near infrared spectroscopy as a neuroimaging modality is a recent development. Near infrared neuroimagers are typically safe, portable, relatively affordable and non-invasive. The ease of sensor setup and non-intrusiveness make functional near infrared (fNIR) imaging an ideal candidate for monitoring human cortical function in a wide range of real world situations. However optical signals are susceptible to motion-artifacts, hindering the application of fNIR in studies where subject mobility cannot be controlled. In this paper, we present a filtering framework for motion-artifact cancellation to facilitate the deployment of fNIR imaging in real-world scenarios. We simulate a generic field environment by having subjects walk on a treadmill while performing a cognitive task and demonstrate that measurements can be effectively cleaned of motion-artifacts.

Using mathematics to solve real world problems: the role of enablers

NASA Astrophysics Data System (ADS)

Geiger, Vincent; Stillman, Gloria; Brown, Jill; Galbriath, Peter; Niss, Mogens

2018-03-01

The purpose of this article is to report on a newly funded research project in which we will investigate how secondary students apply mathematical modelling to effectively address real world situations. Through this study, we will identify factors, mathematical, cognitive, social and environmental that "enable" year 10/11 students to successfully begin the modelling process, that is, formulate and mathematise a real world problem. The 3-year study will take a design research approach in working intensively with six schools across two educational jurisdictions. It is anticipated that this research will generate new theoretical and practical insights into the role of "enablers" within the process of mathematisation, leading to the development of principles for the design and implementation for tasks that support students' development as modellers.

EEG-based cognitive load of processing events in 3D virtual worlds is lower than processing events in 2D displays.

PubMed

Dan, Alex; Reiner, Miriam

2017-12-01

Interacting with 2D displays, such as computer screens, smartphones, and TV, is currently a part of our daily routine; however, our visual system is built for processing 3D worlds. We examined the cognitive load associated with a simple and a complex task of learning paper-folding (origami) by observing 2D or stereoscopic 3D displays. While connected to an electroencephalogram (EEG) system, participants watched a 2D video of an instructor demonstrating the paper-folding tasks, followed by a stereoscopic 3D projection of the same instructor (a digital avatar) illustrating identical tasks. We recorded the power of alpha and theta oscillations and calculated the cognitive load index (CLI) as the ratio of the average power of frontal theta (Fz.) and parietal alpha (Pz). The results showed a significantly higher cognitive load index associated with processing the 2D projection as compared to the 3D projection; additionally, changes in the average theta Fz power were larger for the 2D conditions as compared to the 3D conditions, while alpha average Pz power values were similar for 2D and 3D conditions for the less complex task and higher in the 3D state for the more complex task. The cognitive load index was lower for the easier task and higher for the more complex task in 2D and 3D. In addition, participants with lower spatial abilities benefited more from the 3D compared to the 2D display. These findings have implications for understanding cognitive processing associated with 2D and 3D worlds and for employing stereoscopic 3D technology over 2D displays in designing emerging virtual and augmented reality applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Everyday and prospective memory deficits in ecstasy/polydrug users.

PubMed

Hadjiefthyvoulou, Florentia; Fisk, John E; Montgomery, Catharine; Bridges, Nikola

2011-04-01

The impact of ecstasy/polydrug use on real-world memory (i.e. everyday memory, cognitive failures and prospective memory [PM]) was investigated in a sample of 42 ecstasy/polydrug users and 31 non-ecstasy users. Laboratory-based PM tasks were administered along with self-reported measures of PM to test whether any ecstasy/polydrug-related impairment on the different aspects of PM was present. Self-reported measures of everyday memory and cognitive failures were also administered. Ecstasy/polydrug associated deficits were observed on both laboratory and self-reported measures of PM and everyday memory. The present study extends previous research by demonstrating that deficits in PM are real and cannot be simply attributed to self-misperceptions. The deficits observed reflect some general capacity underpinning both time- and event-based PM contexts and are not task specific. Among this group of ecstasy/polydrug users recreational use of cocaine was also prominently associated with PM deficits. Further research might explore the differential effects of individual illicit drugs on real-world memory.

Age-Related Differences and Cognitive Correlates of Self-Reported and Direct Navigation Performance: The Effect of Real and Virtual Test Conditions Manipulation

PubMed Central

Taillade, Mathieu; N'Kaoua, Bernard; Sauzéon, Hélène

2016-01-01

The present study investigated the effect of aging on direct navigation measures and self-reported ones according to the real-virtual test manipulation. Navigation (wayfinding tasks) and spatial memory (paper-pencil tasks) performances, obtained either in real-world or in virtual-laboratory test conditions, were compared between young (n = 32) and older (n = 32) adults who had self-rated their everyday navigation behavior (SBSOD scale). Real age-related differences were observed in navigation tasks as well as in paper-pencil tasks, which investigated spatial learning relative to the distinction between survey-route knowledge. The manipulation of test conditions (real vs. virtual) did not change these age-related differences, which are mostly explained by age-related decline in both spatial abilities and executive functioning (measured with neuropsychological tests). In contrast, elderly adults did not differ from young adults in their self-reporting relative to everyday navigation, suggesting some underestimation of navigation difficulties by elderly adults. Also, spatial abilities in young participants had a mediating effect on the relations between actual and self-reported navigation performance, but not for older participants. So, it is assumed that the older adults carried out the navigation task with fewer available spatial abilities compared to young adults, resulting in inaccurate self-estimates. PMID:26834666

Age-Related Differences and Cognitive Correlates of Self-Reported and Direct Navigation Performance: The Effect of Real and Virtual Test Conditions Manipulation.

PubMed

Taillade, Mathieu; N'Kaoua, Bernard; Sauzéon, Hélène

2015-01-01

The present study investigated the effect of aging on direct navigation measures and self-reported ones according to the real-virtual test manipulation. Navigation (wayfinding tasks) and spatial memory (paper-pencil tasks) performances, obtained either in real-world or in virtual-laboratory test conditions, were compared between young (n = 32) and older (n = 32) adults who had self-rated their everyday navigation behavior (SBSOD scale). Real age-related differences were observed in navigation tasks as well as in paper-pencil tasks, which investigated spatial learning relative to the distinction between survey-route knowledge. The manipulation of test conditions (real vs. virtual) did not change these age-related differences, which are mostly explained by age-related decline in both spatial abilities and executive functioning (measured with neuropsychological tests). In contrast, elderly adults did not differ from young adults in their self-reporting relative to everyday navigation, suggesting some underestimation of navigation difficulties by elderly adults. Also, spatial abilities in young participants had a mediating effect on the relations between actual and self-reported navigation performance, but not for older participants. So, it is assumed that the older adults carried out the navigation task with fewer available spatial abilities compared to young adults, resulting in inaccurate self-estimates.

On Teaching Energy: Preparing Students Better for their Role as Citizens

NASA Astrophysics Data System (ADS)

Myers, J. D.; Lyford, M. E.; Buss, A.

2009-12-01

Supplying energy to an expanding population with a rising standard of living and maintaining human and natural systems is an increasingly difficult task. Thus, energy is often listed as one of the grand challenges facing humankind. Energy‘s grand challenges are many, complex, multifaceted and of variable scale. It is not surprising then that their solutions must be multi-dimensional as well. Historically, energy solutions have focused on energy science (a multidisciplinary topic spanning biology, chemistry, Earth science, physics, and math), technology or economics. In the real world, focusing solely on these aspects of energy has rarely produced energy projects that are just and fair. Sustainable, equitable and effective energy projects are only created when additional perspectives are considered, e.g. environment, culture, social institutions, politics, etc. The natures of these other perspectives are determined largely by the social context of any particular energy issue. For example, petroleum production has had vastly different impacts in Norway than it does in Nigeria. Thus, solutions to energy issues are, in fact, multidimensional functions. Given this complexity, preparing students to deal with the energy issues they will face in the future requires an instructional approach that integrates a multidisciplinary science approach with technology and social context. Yet this alone will not ensure that students leave the classroom with the skills necessary to equitably, effectively and logically deal with energy issues. Rather, teaching energy also requires sound pedagogy. Effective pedagogy ensures student success in the classroom and facilitates transfer of classroom knowledge to real world situations. It includes, but also goes beyond, employing classroom strategies that promote deep and lasting learning. In this arena, it fosters the development of a skill set that enables students to transfer classroom knowledge to real world issues. It prepares students to handle the uncertainty and ambiguity of the real world while promoting critical thinking and problem solving. Fundamental literacies, a type of QR, prepare students to handle data, perform simple calculations and evaluate critically quantitative claims. They are crucial to working in the real world as well as the scientific realm. Understanding and using scientific content also requires mastering a series of technical literacies. Although they may vary between scientific disciplines, some technical literacies are shared by a number of sciences. Although most science courses assume students can transfer what they have learned to societal applications without further assistance, this is rare, even for the best students. Rather, this classroom-to-real world transfer skill set, i.e. citizenship literacies, must be explicitly taught and practiced. Mastering critical thinking, understanding social context and practicing informed engagement provides students the skills to use their scientific understanding to address energy problems in meaningful and effective ways while enabling them to communicate effectively their ideas to others and work co-operatively with stakeholders with different views.

A bio-inspired kinematic controller for obstacle avoidance during reaching tasks with real robots.

PubMed

Srinivasa, Narayan; Bhattacharyya, Rajan; Sundareswara, Rashmi; Lee, Craig; Grossberg, Stephen

2012-11-01

This paper describes a redundant robot arm that is capable of learning to reach for targets in space in a self-organized fashion while avoiding obstacles. Self-generated movement commands that activate correlated visual, spatial and motor information are used to learn forward and inverse kinematic control models while moving in obstacle-free space using the Direction-to-Rotation Transform (DIRECT). Unlike prior DIRECT models, the learning process in this work was realized using an online Fuzzy ARTMAP learning algorithm. The DIRECT-based kinematic controller is fault tolerant and can handle a wide range of perturbations such as joint locking and the use of tools despite not having experienced them during learning. The DIRECT model was extended based on a novel reactive obstacle avoidance direction (DIRECT-ROAD) model to enable redundant robots to avoid obstacles in environments with simple obstacle configurations. However, certain configurations of obstacles in the environment prevented the robot from reaching the target with purely reactive obstacle avoidance. To address this complexity, a self-organized process of mental rehearsals of movements was modeled, inspired by human and animal experiments on reaching, to generate plans for movement execution using DIRECT-ROAD in complex environments. These mental rehearsals or plans are self-generated by using the Fuzzy ARTMAP algorithm to retrieve multiple solutions for reaching each target while accounting for all the obstacles in its environment. The key aspects of the proposed novel controller were illustrated first using simple examples. Experiments were then performed on real robot platforms to demonstrate successful obstacle avoidance during reaching tasks in real-world environments. Copyright © 2012 Elsevier Ltd. All rights reserved.

The approach to engineering tasks composition on knowledge portals

NASA Astrophysics Data System (ADS)

Novogrudska, Rina; Globa, Larysa; Schill, Alexsander; Romaniuk, Ryszard; Wójcik, Waldemar; Karnakova, Gaini; Kalizhanova, Aliya

2017-08-01

The paper presents an approach to engineering tasks composition on engineering knowledge portals. The specific features of engineering tasks are highlighted, their analysis makes the basis for partial engineering tasks integration. The formal algebraic system for engineering tasks composition is proposed, allowing to set the context-independent formal structures for engineering tasks elements' description. The method of engineering tasks composition is developed that allows to integrate partial calculation tasks into general calculation tasks on engineering portals, performed on user request demand. The real world scenario «Calculation of the strength for the power components of magnetic systems» is represented, approving the applicability and efficiency of proposed approach.

Evaluating TBLT: The Case of a Task-Based Spanish Program

ERIC Educational Resources Information Center

González-Lloret, Marta; Nielson, Katharine B.

2015-01-01

The need for foreign language education in the US has increased in recent years, and teaching methods based on traditional textbooks are unlikely to meet the real-world needs of current learners. As a response, interest in Language for Specific Purposes programs has grown and so has Task-Based Language Teaching (TBLT) methodology. This article…

Creating Thinking and Inquiry Tasks that Reflect the Concerns and Interests of Adolescents

ERIC Educational Resources Information Center

Memory, David M.; Yoder, Carol Y.; Bolinger, Kevin B.; Warren, Wilson J.

2004-01-01

At least since John Dewey published his classic works (Dewey [1916] 1938; 1933; [1938] 1963), teachers have been urged to engage students by using thinking and inquiry tasks that reflect real-world concerns and interests. Subsequent to the appearance of Dewey's discussions of that pedagogical stance, the National Council for the Social Studies…

Regionally Specific Tasks of Non-Western English Language Use

ERIC Educational Resources Information Center

Lanteigne, Betty

2006-01-01

Many English tests based on Western culture are inappropriate for regions where English use differs from that of Europe and North America. In these non-Western settings, it is desirable that English assessments be based on real-world English use. Therefore, identifying tasks of non-Western English language use is a beginning step in developing…

When Knowledge Is Not Enough: The Phenomenon of Goal Neglect in Preschool Children

ERIC Educational Resources Information Center

Towse, John N.; Lewis, Charlie; Knowles, Mark

2007-01-01

We argue that the concept of goal neglect can be fruitfully applied to understand children's potential problems in experimental tasks and real-world settings. We describe an assessment of goal neglect developed for administration to preschool children and report data on two measures derived from this task alongside the Dimensional Change Card Sort…

The Forest, the Trees, and the Leaves: Differences of Processing across Development

ERIC Educational Resources Information Center

Krakowski, Claire-Sara; Poirel, Nicolas; Vidal, Julie; Roëll, Margot; Pineau, Arlette; Borst, Grégoire; Houdé, Olivier

2016-01-01

To act and think, children and adults are continually required to ignore irrelevant visual information to focus on task-relevant items. As real-world visual information is organized into structures, we designed a feature visual search task containing 3-level hierarchical stimuli (i.e., local shapes that constituted intermediate shapes that formed…

Functional connectivity of hippocampal and prefrontal networks during episodic and spatial memory based on real-world environments.

PubMed

Robin, Jessica; Hirshhorn, Marnie; Rosenbaum, R Shayna; Winocur, Gordon; Moscovitch, Morris; Grady, Cheryl L

2015-01-01

Several recent studies have compared episodic and spatial memory in neuroimaging paradigms in order to understand better the contribution of the hippocampus to each of these tasks. In the present study, we build on previous findings showing common neural activation in default network areas during episodic and spatial memory tasks based on familiar, real-world environments (Hirshhorn et al. (2012) Neuropsychologia 50:3094-3106). Following previous demonstrations of the presence of functionally connected sub-networks within the default network, we performed seed-based functional connectivity analyses to determine how, depending on the task, the hippocampus and prefrontal cortex differentially couple with one another and with distinct whole-brain networks. We found evidence for a medial prefrontal-parietal network and a medial temporal lobe network, which were functionally connected to the prefrontal and hippocampal seeds, respectively, regardless of the nature of the memory task. However, these two networks were functionally connected with one another during the episodic memory task, but not during spatial memory tasks. Replicating previous reports of fractionation of the default network into stable sub-networks, this study also shows how these sub-networks may flexibly couple and uncouple with one another based on task demands. These findings support the hypothesis that episodic memory and spatial memory share a common medial temporal lobe-based neural substrate, with episodic memory recruiting additional prefrontal sub-networks. © 2014 Wiley Periodicals, Inc.

Effects of aging on eye movements in the real world

PubMed Central

Dowiasch, Stefan; Marx, Svenja; Einhäuser, Wolfgang; Bremmer, Frank

2015-01-01

The effects of aging on eye movements are well studied in the laboratory. Increased saccade latencies or decreased smooth-pursuit gain are well established findings. The question remains whether these findings are influenced by the rather untypical environment of a laboratory; that is, whether or not they transfer to the real world. We measured 34 healthy participants between the age of 25 and 85 during two everyday tasks in the real world: (I) walking down a hallway with free gaze, (II) visual tracking of an earth-fixed object while walking straight-ahead. Eye movements were recorded with a mobile light-weight eye tracker, the EyeSeeCam (ESC). We find that age significantly influences saccade parameters. With increasing age, saccade frequency, amplitude, peak velocity, and mean velocity are reduced and the velocity/amplitude distribution as well as the velocity profile become less skewed. In contrast to laboratory results on smooth pursuit, we did not find a significant effect of age on tracking eye-movements in the real world. Taken together, age-related eye-movement changes as measured in the laboratory only partly resemble those in the real world. It is well-conceivable that in the real world additional sensory cues, such as head-movement or vestibular signals, may partially compensate for age-related effects, which, according to this view, would be specific to early motion processing. In any case, our results highlight the importance of validity for natural situations when studying the impact of aging on real-life performance. PMID:25713524

Comparison of performance-based assessment and real world skill in people with serious mental illness: Ecological validity of the Test of Grocery Shopping Skills.

PubMed

Faith, Laura A; Rempfer, Melisa V

2018-05-07

Valid functional measures are essential for clinical and research efforts that address recovery and community functioning in people with serious mental illness. Although there is a great deal of interest in functional assessment, there is limited research supporting how well current evaluation methods provide a true assessment of real world functioning or naturalistic behavior. To address this gap in the literature, the present study examined the performance of individuals with serious mental illness (i.e., diagnosis of schizophrenia-spectrum, bipolar disorder, or other depression/anxiety diagnoses and accompanying functional disability) on the Test of Grocery Shopping Skills (TOGSS), a performance-based naturalistic task. We compared TOGSS performance to two dimensions of real world functioning: directly observed real world grocery shopping and ratings of community functioning. Results indicated that the TOGSS was significantly associated with real life grocery shopping, in terms of both shopping accuracy (r = 0.424) and time (r = 0.491). Further, self-report and observer-rated methods of assessing real world shopping behaviors were significantly correlated (r = 0.455). To our knowledge, this is one of the first studies to directly compare a performance-based naturalistic skill assessment with carefully observed real world performance of that skill in people with serious mental illness. These findings support the feasibility and ecological validity of performance-based naturalistic assessment with the TOGSS. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of aging on eye movements in the real world.

PubMed

Dowiasch, Stefan; Marx, Svenja; Einhäuser, Wolfgang; Bremmer, Frank

2015-01-01

The effects of aging on eye movements are well studied in the laboratory. Increased saccade latencies or decreased smooth-pursuit gain are well established findings. The question remains whether these findings are influenced by the rather untypical environment of a laboratory; that is, whether or not they transfer to the real world. We measured 34 healthy participants between the age of 25 and 85 during two everyday tasks in the real world: (I) walking down a hallway with free gaze, (II) visual tracking of an earth-fixed object while walking straight-ahead. Eye movements were recorded with a mobile light-weight eye tracker, the EyeSeeCam (ESC). We find that age significantly influences saccade parameters. With increasing age, saccade frequency, amplitude, peak velocity, and mean velocity are reduced and the velocity/amplitude distribution as well as the velocity profile become less skewed. In contrast to laboratory results on smooth pursuit, we did not find a significant effect of age on tracking eye-movements in the real world. Taken together, age-related eye-movement changes as measured in the laboratory only partly resemble those in the real world. It is well-conceivable that in the real world additional sensory cues, such as head-movement or vestibular signals, may partially compensate for age-related effects, which, according to this view, would be specific to early motion processing. In any case, our results highlight the importance of validity for natural situations when studying the impact of aging on real-life performance.

A novel GLM-based method for the Automatic IDentification of functional Events (AIDE) in fNIRS data recorded in naturalistic environments.

PubMed

Pinti, Paola; Merla, Arcangelo; Aichelburg, Clarisse; Lind, Frida; Power, Sarah; Swingler, Elizabeth; Hamilton, Antonia; Gilbert, Sam; Burgess, Paul W; Tachtsidis, Ilias

2017-07-15

Recent technological advances have allowed the development of portable functional Near-Infrared Spectroscopy (fNIRS) devices that can be used to perform neuroimaging in the real-world. However, as real-world experiments are designed to mimic everyday life situations, the identification of event onsets can be extremely challenging and time-consuming. Here, we present a novel analysis method based on the general linear model (GLM) least square fit analysis for the Automatic IDentification of functional Events (or AIDE) directly from real-world fNIRS neuroimaging data. In order to investigate the accuracy and feasibility of this method, as a proof-of-principle we applied the algorithm to (i) synthetic fNIRS data simulating both block-, event-related and mixed-design experiments and (ii) experimental fNIRS data recorded during a conventional lab-based task (involving maths). AIDE was able to recover functional events from simulated fNIRS data with an accuracy of 89%, 97% and 91% for the simulated block-, event-related and mixed-design experiments respectively. For the lab-based experiment, AIDE recovered more than the 66.7% of the functional events from the fNIRS experimental measured data. To illustrate the strength of this method, we then applied AIDE to fNIRS data recorded by a wearable system on one participant during a complex real-world prospective memory experiment conducted outside the lab. As part of the experiment, there were four and six events (actions where participants had to interact with a target) for the two different conditions respectively (condition 1: social-interact with a person; condition 2: non-social-interact with an object). AIDE managed to recover 3/4 events and 3/6 events for conditions 1 and 2 respectively. The identified functional events were then corresponded to behavioural data from the video recordings of the movements and actions of the participant. Our results suggest that "brain-first" rather than "behaviour-first" analysis is possible and that the present method can provide a novel solution to analyse real-world fNIRS data, filling the gap between real-life testing and functional neuroimaging. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Enhancing Navigation Skills through Audio Gaming.

PubMed

Sánchez, Jaime; Sáenz, Mauricio; Pascual-Leone, Alvaro; Merabet, Lotfi

2010-01-01

We present the design, development and initial cognitive evaluation of an Audio-based Environment Simulator (AbES). This software allows a blind user to navigate through a virtual representation of a real space for the purposes of training orientation and mobility skills. Our findings indicate that users feel satisfied and self-confident when interacting with the audio-based interface, and the embedded sounds allow them to correctly orient themselves and navigate within the virtual world. Furthermore, users are able to transfer spatial information acquired through virtual interactions into real world navigation and problem solving tasks.

Forecasting Device Effectiveness. Volume 2. Procedures

DTIC Science & Technology

1985-06-01

about individual tasks is used to sup- port the fotul ratings. DEFT III. At this level of analysis, the analyst uses 11 rating scales to estimate...real world or are they sust’ined at unreal levels in the training environment? The third scale r3tes how much practice the trainee will have in the...real world ’ I., F. MIMflMfl MM/ MMPMMIMMHrnMN MHIMMIMIHMN/fMhMMM flMhlMlflMMfMM l!"MMt~MWfl l o 20 1) 40 5(0 6() 70 8O 9.’ 1, ,, 0 = None; the

Enhancing Navigation Skills through Audio Gaming

PubMed Central

Sánchez, Jaime; Sáenz, Mauricio; Pascual-Leone, Alvaro; Merabet, Lotfi

2014-01-01

We present the design, development and initial cognitive evaluation of an Audio-based Environment Simulator (AbES). This software allows a blind user to navigate through a virtual representation of a real space for the purposes of training orientation and mobility skills. Our findings indicate that users feel satisfied and self-confident when interacting with the audio-based interface, and the embedded sounds allow them to correctly orient themselves and navigate within the virtual world. Furthermore, users are able to transfer spatial information acquired through virtual interactions into real world navigation and problem solving tasks. PMID:25505796

The role of the dorsal anterior insula in sexual risk: Evidence from an erotic Go/NoGo task and real-world risk-taking.

PubMed

Xue, Feng; Droutman, Vita; Barkley-Levenson, Emily E; Smith, Benjamin J; Xue, Gui; Miller, Lynn C; Bechara, Antoine; Lu, Zhong-Lin; Read, Stephen J

2018-04-01

The insula plays an important role in response inhibition. Most relevant here, it has been proposed that the dorsal anterior insular cortex (dAIC) plays a central role in a salience network that is responsible for switching between the default mode network and the executive control network. However, the insula's role in sexually motivated response inhibition has not yet been studied. In this study, eighty-five 18- to 30-year-old sexually active men who have sex with men (MSM) performed an erotic Go/NoGo task while in an MRI scanner. Participants' real-world sexual risk-taking (frequency of condomless anal intercourse over the past 90 days) was then correlated with their neural activity during the task. We found greater activity in bilateral anterior insular cortex (both dorsal and ventral) on contrasts with stronger motivational information (attractive naked male pictures versus pictures of clothed, middle-aged females) and on contrasts requiring greater response inhibition (NoGo versus Go). We also found that activity in the right dAIC was negatively correlated with participants' real-world sexual risk-taking. Our results confirmed the involvement of the insular cortex in motivated response inhibition. Especially, the decreased right dAIC activity may reduce the likelihood that the executive control network will come online when individuals are faced with situations requiring inhibitory control and thus lead them to make more risky choices. © 2018 Wiley Periodicals, Inc.

The role of trait mindfulness in the pain experience of adolescents.

PubMed

Petter, Mark; Chambers, Christine T; McGrath, Patrick J; Dick, Bruce D

2013-12-01

Trait mindfulness appears to mitigate pain among adult clinical populations and has a unique relationship with pain catastrophizing. However, little is understood about this phenomenon among adolescents. The association between trait mindfulness and pain in both real-world and experimental contexts was examined in a community sample of adolescents. Participants were 198 adolescents who completed measures of trait mindfulness, pain catastrophizing, and pain interference, as well as an interview on day-to-day pain before undergoing an acute experimental pain task. Following the task, they provided ratings of pain intensity and state catastrophizing. Results showed that with regard to day-to-day pains, mindfulness was a significant and unique predictor of pain interference, and this relationship was partially mediated by pain catastrophizing. Mindfulness also had an indirect relationship with experimental pain intensity and tolerance. These associations were mediated by catastrophizing during the pain task. These findings highlight the association between trait mindfulness and both real-world and experimental pain and offer insight into how mindfulness may affect pain among youth. Findings are discussed in the context of current psychological models of pediatric pain and future avenues for research. This article highlights the association between trait mindfulness and pain variables among adolescents in both real-world and experimental pain settings. These findings offer further evidence of the unique relationship between trait mindfulness and pain catastrophizing in affecting pain variables across pain contexts and populations. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

A comparison of the upper limb movement kinematics utilized by children playing virtual and real table tennis.

PubMed

Bufton, Amy; Campbell, Amity; Howie, Erin; Straker, Leon

2014-12-01

Active virtual games (AVG) may facilitate gross motor skill development, depending on their fidelity. This study compared the movement patterns of nineteen 10-12 yr old children, while playing table tennis on three AVG consoles (Nintendo Wii, Xbox Kinect, Sony Move) and as a real world task. Wrist and elbow joint angles and hand path distance and speed were captured. Children playing real table tennis had significantly smaller (e.g. Wrist Angle Forehand Real-Kinect: Mean Difference (MD): -18.2°, 95% Confidence Interval (CI): -26.15 to -10.26) and slower (e.g. Average Speed Forehand Real-Kinect: MD: -1.98 ms(-1), 95% CI: -2.35 to -1.61) movements than when using all three AVGs. Hand path distance was smaller in forehand and backhand strokes (e.g. Kinect-Wii: MD: 0.46 m, 95% CI: 0.13-0.79) during playing with Kinect than Move and Wii. The movement patterns when playing real and virtual table tennis were different and this may impede the development of real world gross motor skills. Several elements, including display, input and task characteristics, may have contributed to the differences in movement patterns observed. Understanding the interface components for AVGs may help development of higher fidelity games to potentially enhance the development of gross motor skill and thus participation in PA. Copyright © 2014 Elsevier B.V. All rights reserved.

Regional Differences in Brain Volume Predict the Acquisition of Skill in a Complex Real-Time Strategy Videogame

PubMed Central

Basak, Chandramallika; Voss, Michelle W.; Erickson, Kirk I.; Boot, Walter R.; Kramer, Arthur F.

2015-01-01

Previous studies have found that differences in brain volume among older adults predict performance in laboratory tasks of executive control, memory, and motor learning. In the present study we asked whether regional differences in brain volume as assessed by the application of a voxel-based morphometry technique on high resolution MRI would also be useful in predicting the acquisition of skill in complex tasks, such as strategy-based video games. Twenty older adults were trained for over 20 hours to play Rise of Nations, a complex real-time strategy game. These adults showed substantial improvements over the training period in game performance. MRI scans obtained prior to training revealed that the volume of a number of brain regions, which have been previously associated with subsets of the trained skills, predicted a substantial amount of variance in learning on the complex game. Thus, regional differences in brain volume can predict learning in complex tasks that entail the use of a variety of perceptual, cognitive and motor processes. PMID:21546146

Regional differences in brain volume predict the acquisition of skill in a complex real-time strategy videogame.

PubMed

Basak, Chandramallika; Voss, Michelle W; Erickson, Kirk I; Boot, Walter R; Kramer, Arthur F

2011-08-01

Previous studies have found that differences in brain volume among older adults predict performance in laboratory tasks of executive control, memory, and motor learning. In the present study we asked whether regional differences in brain volume as assessed by the application of a voxel-based morphometry technique on high resolution MRI would also be useful in predicting the acquisition of skill in complex tasks, such as strategy-based video games. Twenty older adults were trained for over 20 h to play Rise of Nations, a complex real-time strategy game. These adults showed substantial improvements over the training period in game performance. MRI scans obtained prior to training revealed that the volume of a number of brain regions, which have been previously associated with subsets of the trained skills, predicted a substantial amount of variance in learning on the complex game. Thus, regional differences in brain volume can predict learning in complex tasks that entail the use of a variety of perceptual, cognitive and motor processes. Copyright © 2011 Elsevier Inc. All rights reserved.

Working alone or in the presence of others: exploring social facilitation in baggage X-ray security screening tasks.

PubMed

Yu, Rui-feng; Wu, Xin

2015-01-01

This study investigated whether the mere presence of a human audience would evoke a social facilitation effect in baggage X-ray security screening tasks. A 2 (target presence: present vs. absent) ×  2 (task complexity: simple vs. complex) ×  2 (social presence: alone vs. human audience) within-subject experiment simulating a real baggage screening task was conducted. This experiment included 20 male participants. The participants' search performance in this task was recorded. The results showed that the presence of a human audience speeded up responses in simple tasks and slowed down responses in complex tasks. However, the social facilitation effect produced by the presence of a human audience had no effect on response accuracy. These findings suggested that the complexity of screening tasks should be considered when designing work organisation modes for security screening tasks. Practitioner summary: This study investigated whether the presence of a human audience could evoke a social facilitation effect in baggage X-ray security screening tasks. An experimental simulation was conducted. The results showed that the presence of a human audience facilitated the search performance of simple tasks and inhibited the performance of complex tasks.

Uncertainty Reduction for Stochastic Processes on Complex Networks

NASA Astrophysics Data System (ADS)

Radicchi, Filippo; Castellano, Claudio

2018-05-01

Many real-world systems are characterized by stochastic dynamical rules where a complex network of interactions among individual elements probabilistically determines their state. Even with full knowledge of the network structure and of the stochastic rules, the ability to predict system configurations is generally characterized by a large uncertainty. Selecting a fraction of the nodes and observing their state may help to reduce the uncertainty about the unobserved nodes. However, choosing these points of observation in an optimal way is a highly nontrivial task, depending on the nature of the stochastic process and on the structure of the underlying interaction pattern. In this paper, we introduce a computationally efficient algorithm to determine quasioptimal solutions to the problem. The method leverages network sparsity to reduce computational complexity from exponential to almost quadratic, thus allowing the straightforward application of the method to mid-to-large-size systems. Although the method is exact only for equilibrium stochastic processes defined on trees, it turns out to be effective also for out-of-equilibrium processes on sparse loopy networks.

Hierarchical classification of dynamically varying radar pulse repetition interval modulation patterns.

PubMed

Kauppi, Jukka-Pekka; Martikainen, Kalle; Ruotsalainen, Ulla

2010-12-01

The central purpose of passive signal intercept receivers is to perform automatic categorization of unknown radar signals. Currently, there is an urgent need to develop intelligent classification algorithms for these devices due to emerging complexity of radar waveforms. Especially multifunction radars (MFRs) capable of performing several simultaneous tasks by utilizing complex, dynamically varying scheduled waveforms are a major challenge for automatic pattern classification systems. To assist recognition of complex radar emissions in modern intercept receivers, we have developed a novel method to recognize dynamically varying pulse repetition interval (PRI) modulation patterns emitted by MFRs. We use robust feature extraction and classifier design techniques to assist recognition in unpredictable real-world signal environments. We classify received pulse trains hierarchically which allows unambiguous detection of the subpatterns using a sliding window. Accuracy, robustness and reliability of the technique are demonstrated with extensive simulations using both static and dynamically varying PRI modulation patterns. Copyright © 2010 Elsevier Ltd. All rights reserved.

Dynamic phenomena and human activity in an artificial society

NASA Astrophysics Data System (ADS)

Grabowski, A.; Kruszewska, N.; Kosiński, R. A.

2008-12-01

We study dynamic phenomena in a large social network of nearly 3×104 individuals who interact in the large virtual world of a massive multiplayer online role playing game. On the basis of a database received from the online game server, we examine the structure of the friendship network and human dynamics. To investigate the relation between networks of acquaintances in virtual and real worlds, we carried out a survey among the players. We show that, even though the virtual network did not develop as a growing graph of an underlying network of social acquaintances in the real world, it influences it. Furthermore we find very interesting scaling laws concerning human dynamics. Our research shows how long people are interested in a single task and how much time they devote to it. Surprisingly, exponent values in both cases are close to -1 . We calculate the activity of individuals, i.e., the relative time daily devoted to interactions with others in the artificial society. Our research shows that the distribution of activity is not uniform and is highly correlated with the degree of the node, and that such human activity has a significant influence on dynamic phenomena, e.g., epidemic spreading and rumor propagation, in complex networks. We find that spreading is accelerated (an epidemic) or decelerated (a rumor) as a result of superspreaders’ various behavior.

Individual differences in face-looking behavior generalize from the lab to the world.

PubMed

Peterson, Matthew F; Lin, Jing; Zaun, Ian; Kanwisher, Nancy

2016-05-01

Recent laboratory studies have found large, stable individual differences in the location people first fixate when identifying faces, ranging from the brows to the mouth. Importantly, this variation is strongly associated with differences in fixation-specific identification performance such that individuals' recognition ability is maximized when looking at their preferred location (Mehoudar, Arizpe, Baker, & Yovel, 2014; Peterson & Eckstein, 2013). This finding suggests that face representations are retinotopic and individuals enact gaze strategies that optimize identification, yet the extent to which this behavior reflects real-world gaze behavior is unknown. Here, we used mobile eye trackers to test whether individual differences in face gaze generalize from lab to real-world vision. In-lab fixations were measured with a speeded face identification task, while real-world behavior was measured as subjects freely walked around the Massachusetts Institute of Technology campus. We found a strong correlation between the patterns of individual differences in face gaze in the lab and real-world settings. Our findings support the hypothesis that individuals optimize real-world face identification by consistently fixating the same location and thus strongly constraining the space of retinotopic input. The methods developed for this study entailed collecting a large set of high-definition, wide field-of-view natural videos from head-mounted cameras and the viewer's fixation position, allowing us to characterize subjects' actually experienced real-world retinotopic images. These images enable us to ask how vision is optimized not just for the statistics of the "natural images" found in web databases, but of the truly natural, retinotopic images that have landed on actual human retinae during real-world experience.

Task relevance predicts gaze in videos of real moving scenes.

PubMed

Howard, Christina J; Gilchrist, Iain D; Troscianko, Tom; Behera, Ardhendu; Hogg, David C

2011-09-01

Low-level stimulus salience and task relevance together determine the human fixation priority assigned to scene locations (Fecteau and Munoz in Trends Cogn Sci 10(8):382-390, 2006). However, surprisingly little is known about the contribution of task relevance to eye movements during real-world visual search where stimuli are in constant motion and where the 'target' for the visual search is abstract and semantic in nature. Here, we investigate this issue when participants continuously search an array of four closed-circuit television (CCTV) screens for suspicious events. We recorded eye movements whilst participants watched real CCTV footage and moved a joystick to continuously indicate perceived suspiciousness. We find that when multiple areas of a display compete for attention, gaze is allocated according to relative levels of reported suspiciousness. Furthermore, this measure of task relevance accounted for twice the amount of variance in gaze likelihood as the amount of low-level visual changes over time in the video stimuli.

Techniques for Single System Integration of Elastic Simulation Features

NASA Astrophysics Data System (ADS)

Mitchell, Nathan M.

Techniques for simulating the behavior of elastic objects have matured considerably over the last several decades, tackling diverse problems from non-linear models for incompressibility to accurate self-collisions. Alongside these contributions, advances in parallel hardware design and algorithms have made simulation more efficient and affordable than ever before. However, prior research often has had to commit to design choices that compromise certain simulation features to better optimize others, resulting in a fragmented landscape of solutions. For complex, real-world tasks, such as virtual surgery, a holistic approach is desirable, where complex behavior, performance, and ease of modeling are supported equally. This dissertation caters to this goal in the form of several interconnected threads of investigation, each of which contributes a piece of an unified solution. First, it will be demonstrated how various non-linear materials can be combined with lattice deformers to yield simulations with behavioral richness and a high potential for parallelism. This potential will be exploited to show how a hybrid solver approach based on large macroblocks can accelerate the convergence of these deformers. Further extensions of the lattice concept with non-manifold topology will allow for efficient processing of self-collisions and topology change. Finally, these concepts will be explored in the context of a case study on virtual plastic surgery, demonstrating a real-world problem space where these ideas can be combined to build an expressive authoring tool, allowing surgeons to record procedures digitally for future reference or education.

Eye-Tracking as a Tool to Evaluate Functional Ability in Everyday Tasks in Glaucoma.

PubMed

Kasneci, Enkelejda; Black, Alex A; Wood, Joanne M

2017-01-01

To date, few studies have investigated the eye movement patterns of individuals with glaucoma while they undertake everyday tasks in real-world settings. While some of these studies have reported possible compensatory gaze patterns in those with glaucoma who demonstrated good task performance despite their visual field loss, little is known about the complex interaction between field loss and visual scanning strategies and the impact on task performance and, consequently, on quality of life. We review existing approaches that have quantified the effect of glaucomatous visual field defects on the ability to undertake everyday activities through the use of eye movement analysis. Furthermore, we discuss current developments in eye-tracking technology and the potential for combining eye-tracking with virtual reality and advanced analytical approaches. Recent technological developments suggest that systems based on eye-tracking have the potential to assist individuals with glaucomatous loss to maintain or even improve their performance on everyday tasks and hence enhance their long-term quality of life. We discuss novel approaches for studying the visual search behavior of individuals with glaucoma that have the potential to assist individuals with glaucoma, through the use of personalized programs that take into consideration the individual characteristics of their remaining visual field and visual search behavior.

Naturalistic Assessment of Everyday Functioning in Individuals with Mild Cognitive Impairment: The Day Out Task

PubMed Central

Schmitter-Edgecombe, Maureen; McAlister, Courtney; Weakley, Alyssa

2012-01-01

Objective The Day Out Task (DOT), a naturalistic task that requires multitasking in a real-world setting, was used to examine everyday functioning in individuals with mild cognitive impairment (MCI). Method Thirty-eight participants with MCI and 38 cognitively healthy older adult controls prioritized, organized, initiated and completed a number of subtasks in a campus apartment to prepare for a day out (e.g., determine and gather change for bus, bring a magazine). Participants also completed tests assessing cognitive constructs important in multitasking (i.e., retrospective memory, prospective memory, planning). Results Compared to controls, the MCI group required more time to complete the DOT and demonstrated poorer task accuracy, performing more subtasks incompletely and inaccurately. Despite poorer DOT task accuracy, the MCI and control groups approached completion of the DOT in a similar manner. For the MCI group, retrospective memory was a unique predictor of the number of subtasks left incomplete and inaccurate, while prospective memory was a unique predictor of DOT sequencing. The DOT measures, but not the cognitive tests, were predictive of knowledgeable informant report of everyday functioning. Conclusions These findings suggest that difficulty remembering and keeping track of multiple goals and subgoals may contribute to the poorer performance of individuals with MCI in complex everyday situations. PMID:22846035

Eye-Tracking as a Tool to Evaluate Functional Ability in Everyday Tasks in Glaucoma

PubMed Central

Black, Alex A.

2017-01-01

To date, few studies have investigated the eye movement patterns of individuals with glaucoma while they undertake everyday tasks in real-world settings. While some of these studies have reported possible compensatory gaze patterns in those with glaucoma who demonstrated good task performance despite their visual field loss, little is known about the complex interaction between field loss and visual scanning strategies and the impact on task performance and, consequently, on quality of life. We review existing approaches that have quantified the effect of glaucomatous visual field defects on the ability to undertake everyday activities through the use of eye movement analysis. Furthermore, we discuss current developments in eye-tracking technology and the potential for combining eye-tracking with virtual reality and advanced analytical approaches. Recent technological developments suggest that systems based on eye-tracking have the potential to assist individuals with glaucomatous loss to maintain or even improve their performance on everyday tasks and hence enhance their long-term quality of life. We discuss novel approaches for studying the visual search behavior of individuals with glaucoma that have the potential to assist individuals with glaucoma, through the use of personalized programs that take into consideration the individual characteristics of their remaining visual field and visual search behavior. PMID:28293433

Robust Real-Time Music Transcription with a Compositional Hierarchical Model.

PubMed

Pesek, Matevž; Leonardis, Aleš; Marolt, Matija

2017-01-01

The paper presents a new compositional hierarchical model for robust music transcription. Its main features are unsupervised learning of a hierarchical representation of input data, transparency, which enables insights into the learned representation, as well as robustness and speed which make it suitable for real-world and real-time use. The model consists of multiple layers, each composed of a number of parts. The hierarchical nature of the model corresponds well to hierarchical structures in music. The parts in lower layers correspond to low-level concepts (e.g. tone partials), while the parts in higher layers combine lower-level representations into more complex concepts (tones, chords). The layers are learned in an unsupervised manner from music signals. Parts in each layer are compositions of parts from previous layers based on statistical co-occurrences as the driving force of the learning process. In the paper, we present the model's structure and compare it to other hierarchical approaches in the field of music information retrieval. We evaluate the model's performance for the multiple fundamental frequency estimation. Finally, we elaborate on extensions of the model towards other music information retrieval tasks.

The Origin of Complex Quantum Amplitudes

NASA Astrophysics Data System (ADS)

Goyal, Philip; Knuth, Kevin H.; Skilling, John

2009-12-01

Physics is real. Measurement produces real numbers. Yet quantum mechanics uses complex arithmetic, in which √-1 is necessary but mysteriously relates to nothing else. By applying the same sort of symmetry arguments that Cox [1, 2] used to justify probability calculus, we are now able to explain this puzzle. The dual device/object nature of observation requires us to describe the world in terms of pairs of real numbers about which we never have full knowledge. These pairs combine according to complex arithmetic, using Feynman's rules.

Software Tools for Formal Specification and Verification of Distributed Real-Time Systems.

DTIC Science & Technology

1997-09-30

set of software tools for specification and verification of distributed real time systems using formal methods. The task of this SBIR Phase II effort...to be used by designers of real - time systems for early detection of errors. The mathematical complexity of formal specification and verification has

The ground truth about metadata and community detection in networks

PubMed Central

Peel, Leto; Larremore, Daniel B.; Clauset, Aaron

2017-01-01

Across many scientific domains, there is a common need to automatically extract a simplified view or coarse-graining of how a complex system’s components interact. This general task is called community detection in networks and is analogous to searching for clusters in independent vector data. It is common to evaluate the performance of community detection algorithms by their ability to find so-called ground truth communities. This works well in synthetic networks with planted communities because these networks’ links are formed explicitly based on those known communities. However, there are no planted communities in real-world networks. Instead, it is standard practice to treat some observed discrete-valued node attributes, or metadata, as ground truth. We show that metadata are not the same as ground truth and that treating them as such induces severe theoretical and practical problems. We prove that no algorithm can uniquely solve community detection, and we prove a general No Free Lunch theorem for community detection, which implies that there can be no algorithm that is optimal for all possible community detection tasks. However, community detection remains a powerful tool and node metadata still have value, so a careful exploration of their relationship with network structure can yield insights of genuine worth. We illustrate this point by introducing two statistical techniques that can quantify the relationship between metadata and community structure for a broad class of models. We demonstrate these techniques using both synthetic and real-world networks, and for multiple types of metadata and community structures. PMID:28508065

Evaluating Augmented Reality to Complete a Chain Task for Elementary Students with Autism

ERIC Educational Resources Information Center

Cihak, David F.; Moore, Eric J.; Wright, Rachel E.; McMahon, Don D.; Gibbons, Melinda M.; Smith, Cate

2016-01-01

The purpose of this study was to examine the effects of augmented reality to teach a chain task to three elementary-age students with autism spectrum disorders (ASDs). Augmented reality blends digital information within the real world. This study used a marker-based augmented reality picture prompt to trigger a video model clip of a student…

Confronting Analytical Dilemmas for Understanding Complex Human Interactions in Design-Based Research from a Cultural-Historical Activity Theory (CHAT) Framework

ERIC Educational Resources Information Center

Yamagata-Lynch, Lisa C.

2007-01-01

Understanding human activity in real-world situations often involves complicated data collection, analysis, and presentation methods. This article discusses how Cultural-Historical Activity Theory (CHAT) can inform design-based research practices that focus on understanding activity in real-world situations. I provide a sample data set with…

Negative decision outcomes are more common among people with lower decision-making competence: an item-level analysis of the Decision Outcome Inventory (DOI).

PubMed

Parker, Andrew M; Bruine de Bruin, Wändi; Fischhoff, Baruch

2015-01-01

Most behavioral decision research takes place in carefully controlled laboratory settings, and examination of relationships between performance and specific real-world decision outcomes is rare. One prior study shows that people who perform better on hypothetical decision tasks, assessed using the Adult Decision-Making Competence (A-DMC) measure, also tend to experience better real-world decision outcomes, as reported on the Decision Outcomes Inventory (DOI). The DOI score reflects avoidance of outcomes that could result from poor decisions, ranging from serious (e.g., bankruptcy) to minor (e.g., blisters from sunburn). The present analyses go beyond the initial work, which focused on the overall DOI score, by analyzing the relationships between specific decision outcomes and A-DMC performance. Most outcomes are significantly more likely among people with lower A-DMC scores, even after taking into account two variables expected to produce worse real-world decision outcomes: younger age and lower socio-economic status. We discuss the usefulness of DOI as a measure of successful real-world decision-making.

O.A.T.S.: What the Real World Needs in Reading, Writing, Speaking, and Listening: Occupational Application of Tasks and Skills in Reading, Writing, Speaking, and Listening--A Communication Application Curriculum and Tech Prep Project.

ERIC Educational Resources Information Center

Bradley, Gaylene K.; Winfield, Collette M.

Enabling teachers at both the secondary and post-secondary levels to show students the communication skills they need to be successful in particular careers, this paper presents the reading, writing, speaking, and listening tasks routinely performed by persons working in a variety of occupational tasks. Occupations listed in the paper are divided…

Functional brain imaging of a complex navigation task following one night of total sleep deprivation

NASA Technical Reports Server (NTRS)

Strangman, Gary; Thompson, John H.; Strauss, Monica M.; Marshburn, Thomas H.; Sutton, Jeffrey P.

2006-01-01

Study Objectives: To assess the cerebral effects associated with sleep deprivation in a simulation of a complex, real-world, high-risk task. Design and Interventions: A two-week, repeated measures, cross-over experimental protocol, with counterbalanced orders of normal sleep (NS) and total sleep deprivation (TSD). Setting: Each subject underwent functional magnetic resonance imaging (fMRI) while performing a dual-joystick, 3D sensorimotor navigation task (simulated orbital docking). Scanning was performed twice per subject, once following a night of normal sleep (NS), and once following a single night of total sleep deprivation (TSD). Five runs (eight 24s docking trials each) were performed during each scanning session. Participants: Six healthy, young, right-handed volunteers (2 women; mean age 20) participated. Measurements and Results: Behavioral performance on multiple measures was comparable in the two sleep conditions. Neuroimaging results within sleep conditions revealed similar locations of peak activity for NS and TSD, including left sensorimotor cortex, left precuneus (BA 7), and right visual areas (BA 18/19). However, cerebral activation following TSD was substantially larger and exhibited higher amplitude modulations from baseline. When directly comparing NS and TSD, most regions exhibited TSD>NS activity, including multiple prefrontal cortical areas (BA 8/9,44/45,47), lateral parieto-occipital areas (BA 19/39, 40), superior temporal cortex (BA 22), and bilateral thalamus and amygdala. Only left parietal cortex (BA 7) demonstrated NS>TSD activity. Conclusions: The large network of cerebral differences between the two conditions, even with comparable behavioral performance, suggests the possibility of detecting TSD-induced stress via functional brain imaging techniques on complex tasks before stress-induced failures.

Argument Complexity: Teaching Undergraduates to Make Better Arguments

ERIC Educational Resources Information Center

Kelly, Matthew A.; West, Robert L.

2017-01-01

The task of turning undergrads into academics requires teaching them to reason about the world in a more complex way. We present the Argument Complexity Scale, a tool for analysing the complexity of argumentation, based on the Integrative Complexity and Conceptual Complexity Scales from, respectively, political psychology and personality theory.…

Two Fifth Grade Teachers' Use of Real-World Situations in Science and Mathematics Lessons

ERIC Educational Resources Information Center

Yanik, H. Bahadir; Serin, Gokhan

2016-01-01

The purpose of this study was to investigate the types, sources, and cognitive levels of tasks that included real-life situations used in science and mathematics lessons in the classrooms of two 5th-grade teachers at an urban elementary school in Turkey. A qualitative approach was used to analyze data that included classroom observations, teacher…

Optimizing students' motivation in inquiry-based learning environments: The role of instructional practices

NASA Astrophysics Data System (ADS)

Kempler, Toni M.

The influence of inquiry science instruction on the motivation of 1360 minority inner-city seventh graders was examined. The project-based curriculum incorporates motivating features like real world questions, collaboration, technology, and lesson variety. Students design investigations, collect and analyze data, and create artifacts; challenging tasks require extensive use of learning and metacognitive strategies. Study 1 used Structural Equation Modeling to investigate student perceptions of the prevalence of project-based features, including real world connections, collaboration, academic press, and work norms, and their relation to interest, efficacy, cognitive engagement, and achievement. Perceptions of features related to different motivational outcomes, indicating the importance of using differentiated rather than single measures to study motivation in context. Cognitive engagement was enhanced by interest and efficacy but did not influence achievement, perhaps because students were not proficient strategy users and were new to inquiry. Study 2 examined the relationship between instructional practices and motivation. The 23 teachers in study 1 were observed six times during one unit. Observations focused on curriculum congruence, content accuracy, contextualization, sense making, and management and climate. A majority of teacher enactment was congruent with the curriculum, indicating that students experienced motivating features of project-based science. Hierarchical Linear Modeling showed that contextualization accounted for between-teacher variance in student interest, efficacy, and cognitive engagement; Teachers encouraged motivation through extended real world examples that related material to students' experiences. Cluster analysis was used to determine how patterns of practice affected motivation. Unexpectedly these patterns did not differentially relate to cognitive engagement. Findings showed that interest and efficacy were enhanced when teachers used particular sense making practices. These teachers provided explicit scaffolding for accomplishing complex tasks with questioning and feedback that highlighted key points. Teachers also used effective management practices and maintained a positive classroom climate. In contrast, a pattern of practice where teachers used questioning and feedback to press students to make connections and synthesize concepts without scaffolding support diminished motivation, because students may have needed more help to deal with challenge. Implications from both studies suggest inquiry teachers need to use explicit scaffolding and academic press together, with effective management practices, to support motivation.

Real-Time Sentence Processing in Children with Specific Language Impairment: The Contribution of Lexicosemantic, Syntactic, and World-Knowledge Information

ERIC Educational Resources Information Center

Pizzioli, Fabrizio; Schelstraete, Marie-Anne

2013-01-01

The present study investigated how lexicosemantic information, syntactic information, and world knowledge are integrated in the course of oral sentence processing in children with specific language impairment (SLI) as compared to children with typical language development. A primed lexical-decision task was used where participants had to make a…

Development of detection and recognition of orientation of geometric and real figures.

PubMed

Stein, N L; Mandler, J M

1975-06-01

Black and white kindergarten and second-grade children were tested for accuracy of detection and recognition of orientation and location changes in pictures of real-world and geometric figures. No differences were found in accuracy of recognition between the 2 kinds of pictures, but patterns of verbalization differed on specific transformations. Although differences in accuracy were found between kindergarten and second grade on an initial recognition task, practice on a matching-to-sample task eliminated differences on a second recognition task. Few ethnic differences were found on accuracy of recognition, but significant differences were found in amount of verbal output on specific transformations. For both groups, mention of orientation changes was markedly reduced when location changes were present.

Hypertext-based design of a user interface for scheduling

NASA Technical Reports Server (NTRS)

Woerner, Irene W.; Biefeld, Eric

1993-01-01

Operations Mission Planner (OMP) is an ongoing research project at JPL that utilizes AI techniques to create an intelligent, automated planning and scheduling system. The information space reflects the complexity and diversity of tasks necessary in most real-world scheduling problems. Thus the problem of the user interface is to present as much information as possible at a given moment and allow the user to quickly navigate through the various types of displays. This paper describes a design which applies the hypertext model to solve these user interface problems. The general paradigm is to provide maps and search queries to allow the user to quickly find an interesting conflict or problem, and then allow the user to navigate through the displays in a hypertext fashion.

Automatic guidance of attention during real-world visual search.

PubMed

Seidl-Rathkopf, Katharina N; Turk-Browne, Nicholas B; Kastner, Sabine

2015-08-01

Looking for objects in cluttered natural environments is a frequent task in everyday life. This process can be difficult, because the features, locations, and times of appearance of relevant objects often are not known in advance. Thus, a mechanism by which attention is automatically biased toward information that is potentially relevant may be helpful. We tested for such a mechanism across five experiments by engaging participants in real-world visual search and then assessing attentional capture for information that was related to the search set but was otherwise irrelevant. Isolated objects captured attention while preparing to search for objects from the same category embedded in a scene, as revealed by lower detection performance (Experiment 1A). This capture effect was driven by a central processing bottleneck rather than the withdrawal of spatial attention (Experiment 1B), occurred automatically even in a secondary task (Experiment 2A), and reflected enhancement of matching information rather than suppression of nonmatching information (Experiment 2B). Finally, attentional capture extended to objects that were semantically associated with the target category (Experiment 3). We conclude that attention is efficiently drawn towards a wide range of information that may be relevant for an upcoming real-world visual search. This mechanism may be adaptive, allowing us to find information useful for our behavioral goals in the face of uncertainty.

Connecting Artificial Brains to Robots in a Comprehensive Simulation Framework: The Neurorobotics Platform

PubMed Central

Falotico, Egidio; Vannucci, Lorenzo; Ambrosano, Alessandro; Albanese, Ugo; Ulbrich, Stefan; Vasquez Tieck, Juan Camilo; Hinkel, Georg; Kaiser, Jacques; Peric, Igor; Denninger, Oliver; Cauli, Nino; Kirtay, Murat; Roennau, Arne; Klinker, Gudrun; Von Arnim, Axel; Guyot, Luc; Peppicelli, Daniel; Martínez-Cañada, Pablo; Ros, Eduardo; Maier, Patrick; Weber, Sandro; Huber, Manuel; Plecher, David; Röhrbein, Florian; Deser, Stefan; Roitberg, Alina; van der Smagt, Patrick; Dillman, Rüdiger; Levi, Paul; Laschi, Cecilia; Knoll, Alois C.; Gewaltig, Marc-Oliver

2017-01-01

Combined efforts in the fields of neuroscience, computer science, and biology allowed to design biologically realistic models of the brain based on spiking neural networks. For a proper validation of these models, an embodiment in a dynamic and rich sensory environment, where the model is exposed to a realistic sensory-motor task, is needed. Due to the complexity of these brain models that, at the current stage, cannot deal with real-time constraints, it is not possible to embed them into a real-world task. Rather, the embodiment has to be simulated as well. While adequate tools exist to simulate either complex neural networks or robots and their environments, there is so far no tool that allows to easily establish a communication between brain and body models. The Neurorobotics Platform is a new web-based environment that aims to fill this gap by offering scientists and technology developers a software infrastructure allowing them to connect brain models to detailed simulations of robot bodies and environments and to use the resulting neurorobotic systems for in silico experimentation. In order to simplify the workflow and reduce the level of the required programming skills, the platform provides editors for the specification of experimental sequences and conditions, environments, robots, and brain–body connectors. In addition to that, a variety of existing robots and environments are provided. This work presents the architecture of the first release of the Neurorobotics Platform developed in subproject 10 “Neurorobotics” of the Human Brain Project (HBP).1 At the current state, the Neurorobotics Platform allows researchers to design and run basic experiments in neurorobotics using simulated robots and simulated environments linked to simplified versions of brain models. We illustrate the capabilities of the platform with three example experiments: a Braitenberg task implemented on a mobile robot, a sensory-motor learning task based on a robotic controller, and a visual tracking embedding a retina model on the iCub humanoid robot. These use-cases allow to assess the applicability of the Neurorobotics Platform for robotic tasks as well as in neuroscientific experiments. PMID:28179882

Connecting Artificial Brains to Robots in a Comprehensive Simulation Framework: The Neurorobotics Platform.

PubMed

Falotico, Egidio; Vannucci, Lorenzo; Ambrosano, Alessandro; Albanese, Ugo; Ulbrich, Stefan; Vasquez Tieck, Juan Camilo; Hinkel, Georg; Kaiser, Jacques; Peric, Igor; Denninger, Oliver; Cauli, Nino; Kirtay, Murat; Roennau, Arne; Klinker, Gudrun; Von Arnim, Axel; Guyot, Luc; Peppicelli, Daniel; Martínez-Cañada, Pablo; Ros, Eduardo; Maier, Patrick; Weber, Sandro; Huber, Manuel; Plecher, David; Röhrbein, Florian; Deser, Stefan; Roitberg, Alina; van der Smagt, Patrick; Dillman, Rüdiger; Levi, Paul; Laschi, Cecilia; Knoll, Alois C; Gewaltig, Marc-Oliver

2017-01-01

Combined efforts in the fields of neuroscience, computer science, and biology allowed to design biologically realistic models of the brain based on spiking neural networks. For a proper validation of these models, an embodiment in a dynamic and rich sensory environment, where the model is exposed to a realistic sensory-motor task, is needed. Due to the complexity of these brain models that, at the current stage, cannot deal with real-time constraints, it is not possible to embed them into a real-world task. Rather, the embodiment has to be simulated as well. While adequate tools exist to simulate either complex neural networks or robots and their environments, there is so far no tool that allows to easily establish a communication between brain and body models. The Neurorobotics Platform is a new web-based environment that aims to fill this gap by offering scientists and technology developers a software infrastructure allowing them to connect brain models to detailed simulations of robot bodies and environments and to use the resulting neurorobotic systems for in silico experimentation. In order to simplify the workflow and reduce the level of the required programming skills, the platform provides editors for the specification of experimental sequences and conditions, environments, robots, and brain-body connectors. In addition to that, a variety of existing robots and environments are provided. This work presents the architecture of the first release of the Neurorobotics Platform developed in subproject 10 "Neurorobotics" of the Human Brain Project (HBP). At the current state, the Neurorobotics Platform allows researchers to design and run basic experiments in neurorobotics using simulated robots and simulated environments linked to simplified versions of brain models. We illustrate the capabilities of the platform with three example experiments: a Braitenberg task implemented on a mobile robot, a sensory-motor learning task based on a robotic controller, and a visual tracking embedding a retina model on the iCub humanoid robot. These use-cases allow to assess the applicability of the Neurorobotics Platform for robotic tasks as well as in neuroscientific experiments.

15-Month-Olds’ Transfer of Learning between Touch Screen and Real-World Displays: Language Cues and Cognitive Loads

PubMed Central

Zack, Elizabeth; Gerhardstein, Peter; Meltzoff, Andrew N.; Barr, Rachel

2012-01-01

Infants have difficulty transferring information between 2D and 3D sources. The current study extends Zack et al.’s (2009) touch screen imitation task to examine whether the addition of specific language cues significantly facilitates 15-month-olds’ transfer of learning between touch screens and real-world 3D objects. The addition of two kinds of linguistic cues (object label plus verb or nonsense name) did not elevate action imitation significantly above levels observed when such language cues were not used. Language cues hindered infants’ performance in the 3D→2D direction of transfer, but only for the object label plus verb condition. The lack of a facilitative effect of language is discussed in terms of competing cognitive loads imposed by conjointly transferring information across dimensions and processing linguistic cues in an action imitation task at this age. PMID:23121508

Sampling from complex networks using distributed learning automata

NASA Astrophysics Data System (ADS)

Rezvanian, Alireza; Rahmati, Mohammad; Meybodi, Mohammad Reza

2014-02-01

A complex network provides a framework for modeling many real-world phenomena in the form of a network. In general, a complex network is considered as a graph of real world phenomena such as biological networks, ecological networks, technological networks, information networks and particularly social networks. Recently, major studies are reported for the characterization of social networks due to a growing trend in analysis of online social networks as dynamic complex large-scale graphs. Due to the large scale and limited access of real networks, the network model is characterized using an appropriate part of a network by sampling approaches. In this paper, a new sampling algorithm based on distributed learning automata has been proposed for sampling from complex networks. In the proposed algorithm, a set of distributed learning automata cooperate with each other in order to take appropriate samples from the given network. To investigate the performance of the proposed algorithm, several simulation experiments are conducted on well-known complex networks. Experimental results are compared with several sampling methods in terms of different measures. The experimental results demonstrate the superiority of the proposed algorithm over the others.

Attentional Demand of a Virtual Reality-Based Reaching Task in Nondisabled Older Adults.

PubMed

Chen, Yi-An; Chung, Yu-Chen; Proffitt, Rachel; Wade, Eric; Winstein, Carolee

2015-12-01

Attention during exercise is known to affect performance; however, the attentional demand inherent to virtual reality (VR)-based exercise is not well understood. We used a dual-task paradigm to compare the attentional demands of VR-based and non-VR-based (conventional, real-world) exercise: 22 non-disabled older adults performed a primary reaching task to virtual and real targets in a counterbalanced block order while verbally responding to an unanticipated auditory tone in one third of the trials. The attentional demand of the primary reaching task was inferred from the voice response time (VRT) to the auditory tone. Participants' engagement level and task experience were also obtained using questionnaires. The virtual target condition was more attention demanding (significantly longer VRT) than the real target condition. Secondary analyses revealed a significant interaction between engagement level and target condition on attentional demand. For participants who were highly engaged, attentional demand was high and independent of target condition. However, for those who were less engaged, attentional demand was low and depended on target condition (i.e., virtual > real). These findings add important knowledge to the growing body of research pertaining to the development and application of technology-enhanced exercise for elders and for rehabilitation purposes.

Attentional Demand of a Virtual Reality-Based Reaching Task in Nondisabled Older Adults

PubMed Central

Chen, Yi-An; Chung, Yu-Chen; Proffitt, Rachel; Wade, Eric; Winstein, Carolee

2015-01-01

Attention during exercise is known to affect performance; however, the attentional demand inherent to virtual reality (VR)-based exercise is not well understood. We used a dual-task paradigm to compare the attentional demands of VR-based and non-VR-based (conventional, real-world) exercise: 22 non-disabled older adults performed a primary reaching task to virtual and real targets in a counterbalanced block order while verbally responding to an unanticipated auditory tone in one third of the trials. The attentional demand of the primary reaching task was inferred from the voice response time (VRT) to the auditory tone. Participants' engagement level and task experience were also obtained using questionnaires. The virtual target condition was more attention demanding (significantly longer VRT) than the real target condition. Secondary analyses revealed a significant interaction between engagement level and target condition on attentional demand. For participants who were highly engaged, attentional demand was high and independent of target condition. However, for those who were less engaged, attentional demand was low and depended on target condition (i.e., virtual > real). These findings add important knowledge to the growing body of research pertaining to the development and application of technology-enhanced exercise for elders and for rehabilitation purposes. PMID:27004233

Real-Time linux dynamic clamp: a fast and flexible way to construct virtual ion channels in living cells.

PubMed

Dorval, A D; Christini, D J; White, J A

2001-10-01

We describe a system for real-time control of biological and other experiments. This device, based around the Real-Time Linux operating system, was tested specifically in the context of dynamic clamping, a demanding real-time task in which a computational system mimics the effects of nonlinear membrane conductances in living cells. The system is fast enough to represent dozens of nonlinear conductances in real time at clock rates well above 10 kHz. Conductances can be represented in deterministic form, or more accurately as discrete collections of stochastically gating ion channels. Tests were performed using a variety of complex models of nonlinear membrane mechanisms in excitable cells, including simulations of spatially extended excitable structures, and multiple interacting cells. Only in extreme cases does the computational load interfere with high-speed "hard" real-time processing (i.e., real-time processing that never falters). Freely available on the worldwide web, this experimental control system combines good performance. immense flexibility, low cost, and reasonable ease of use. It is easily adapted to any task involving real-time control, and excels in particular for applications requiring complex control algorithms that must operate at speeds over 1 kHz.

Task analysis of autonomous on-road driving

NASA Astrophysics Data System (ADS)

Barbera, Anthony J.; Horst, John A.; Schlenoff, Craig I.; Aha, David W.

2004-12-01

The Real-time Control System (RCS) Methodology has evolved over a number of years as a technique to capture task knowledge and organize it into a framework conducive to implementation in computer control systems. The fundamental premise of this methodology is that the present state of the task activities sets the context that identifies the requirements for all of the support processing. In particular, the task context at any time determines what is to be sensed in the world, what world model states are to be evaluated, which situations are to be analyzed, what plans should be invoked, and which behavior generation knowledge is to be accessed. This methodology concentrates on the task behaviors explored through scenario examples to define a task decomposition tree that clearly represents the branching of tasks into layers of simpler and simpler subtask activities. There is a named branching condition/situation identified for every fork of this task tree. These become the input conditions of the if-then rules of the knowledge set that define how the task is to respond to input state changes. Detailed analysis of each branching condition/situation is used to identify antecedent world states and these, in turn, are further analyzed to identify all of the entities, objects, and attributes that have to be sensed to determine if any of these world states exist. This paper explores the use of this 4D/RCS methodology in some detail for the particular task of autonomous on-road driving, which work was funded under the Defense Advanced Research Project Agency (DARPA) Mobile Autonomous Robot Software (MARS) effort (Doug Gage, Program Manager).

Set as an instance of a real-world visual-cognitive task.

PubMed

Nyamsuren, Enkhbold; Taatgen, Niels A

2013-01-01

Complex problem solving is often an integration of perceptual processing and deliberate planning. But what balances these two processes, and how do novices differ from experts? We investigate the interplay between these two in the game of SET. This article investigates how people combine bottom-up visual processes and top-down planning to succeed in this game. Using combinatorial and mixed-effect regression analysis of eye-movement protocols and a cognitive model of a human player, we show that SET players deploy both bottom-up and top-down processes in parallel to accomplish the same task. The combination of competition and cooperation of both types of processes is a major factor of success in the game. Finally, we explore strategies players use during the game. Our findings suggest that within-trial strategy shifts can occur without the need of explicit meta-cognitive control, but rather implicitly as a result of evolving memory activations. Copyright © 2012 Cognitive Science Society, Inc.

Vigilance: A Review of the Literature and Applications to Sentry Duty

DOE Office of Scientific and Technical Information (OSTI.GOV)

See, Judi E.

2014-09-01

Vigilance, or sustained attention, involves the ability to maintain focus and remain alert for prolonged periods of time. Problems associated with the ability to sustain attention were first identified in real-world combat situations during World War II, and they continue to abound and evolve as new and different types of situations requiring vigilance arise. This paper provides a review of the vigilance literature that describes the primary psychophysical, task, environmental, pharmacological, and individual factors that impact vigilance performance. The paper also describes how seminal findings from vigilance research apply specifically to the task of sentry duty. The strengths and weaknessesmore » of a human sentry and options to integrate human and automated functions for vigilance tasks are discussed. Finally, techniques that may improve vigilance performance for sentry duty tasks are identified.« less

Solving Real World Problems with Alternate Reality Gaming: Student Experiences in the Global Village Playground Capstone Course Design

ERIC Educational Resources Information Center

Dondlinger, Mary Jo; McLeod, Julie K.

2015-01-01

The Global Village Playground (GVP) was a capstone learning experience designed to address institutional assessment needs while providing an integrated and authentic learning experience for students aimed at fostering complex problem solving, as well as critical and creative thinking. In the GVP, students work on simulated and real-world problems…

Reading-Related Literacy Activities of American Adults: Time Spent, Task Types, and Cognitive Skills Used

ERIC Educational Resources Information Center

White, Sheida; Chen, Jing; Forsyth, Barbara

2010-01-01

This article presents data on the types and duration of reading-related activities reported by a volunteer sample of 400 adults (demographically similar to the U.S. adult population age 20 and older in terms of race, ethnicity, education, and working status) in the 2005 Real-World Tasks Study. This diary study revealed that adults spent, on…

Measuring mental workload: ocular astigmatism aberration as a novel objective index.

PubMed

Jiménez, Raimundo; Cárdenas, David; González-Anera, Rosario; Jiménez, José R; Vera, Jesús

2018-04-01

This study assessed the effect of two perceptually matched mental tasks with different levels of mental demand on ocular aberrations in a group of young adults. We measured ocular aberration with a wavefront sensor, and total, internal and corneal RMS (root mean square) aberrations were calculated from Zernike coefficients, considering natural and scaled pupils (5, 4.5, and 4 mm). We found that total, internal and corneal astigmatism RMS showed significant differences between mental tasks with natural pupils (p < .05), and this effect was maintained with 5 mm scaled pupils (total RMS astigmatism, p < .05). Consistently, pupil size, intraocular pressure, perceived mental load and cognitive performance were influenced by the level of mental complexity (p < .05 for all). The findings suggest that ocular astigmatism aberration, mediated by intraocular pressure, could be an objective, valid reliable index to evaluate the impact of cognitive processing in conjunction with others physiological markers in real world contexts. Practitioner Summary: The search continues for a valid, reliable, convenient method of measuring mental workload. In this study we found ocular astigmatism aberration is sensitive to the cumulative effect of mental effort. It shows promise of being a novel ocular index which may help to assess mental workload in real situations.

Pattern Formation and Complexity Emergence

NASA Astrophysics Data System (ADS)

Berezin, Alexander A.

2001-03-01

Success of nonlinear modelling of pattern formation and self-organization encourages speculations on informational and number theoretical foundations of complexity emergence. Pythagorean "unreasonable effectiveness of integers" in natural processes is perhaps extrapolatable even to universal emergence "out-of-nothing" (Leibniz, Wheeler). Because rational numbers (R = M/N) are everywhere dense on real axis, any digital string (hence any "book" from "Library of Babel" of J.L.Borges) is "recorded" infinitely many times in arbitrary many rationals. Furthermore, within any arbitrary small interval there are infinitely many Rs for which (either or both) integers (Ms and Ns) "carry" any given string of any given length. Because any iterational process (such as generation of fractal features of Mandelbrot Set) is arbitrary closely approximatable with rational numbers, the infinite pattern of integers expresses itself in generation of complexity of the world, as well as in emergence of the world itself. This "tunnelling" from Platonic World ("Platonia" of J.Barbour) to a real (physical) world is modern recast of Leibniz's motto ("for deriving all from nothing there suffices a single principle").

Everyday episodic memory in amnestic mild cognitive impairment: a preliminary investigation.

PubMed

Irish, Muireann; Lawlor, Brian A; Coen, Robert F; O'Mara, Shane M

2011-08-04

Decline in episodic memory is one of the hallmark features of Alzheimer's disease (AD) and is also a defining feature of amnestic Mild Cognitive Impairment (MCI), which is posited as a potential prodrome of AD. While deficits in episodic memory are well documented in MCI, the nature of this impairment remains relatively under-researched, particularly for those domains with direct relevance and meaning for the patient's daily life. In order to fully explore the impact of disruption to the episodic memory system on everyday memory in MCI, we examined participants' episodic memory capacity using a battery of experimental tasks with real-world relevance. We investigated episodic acquisition and delayed recall (story-memory), associative memory (face-name pairings), spatial memory (route learning and recall), and memory for everyday mundane events in 16 amnestic MCI and 18 control participants. Furthermore, we followed MCI participants longitudinally to gain preliminary evidence regarding the possible predictive efficacy of these real-world episodic memory tasks for subsequent conversion to AD. The most discriminating tests at baseline were measures of acquisition, delayed recall, and associative memory, followed by everyday memory, and spatial memory tasks, with MCI patients scoring significantly lower than controls. At follow-up (mean time elapsed: 22.4 months), 6 MCI cases had progressed to clinically probable AD. Exploratory logistic regression analyses revealed that delayed associative memory performance at baseline was a potential predictor of subsequent conversion to AD. As a preliminary study, our findings suggest that simple associative memory paradigms with real-world relevance represent an important line of enquiry in future longitudinal studies charting MCI progression over time.

A neuro-fuzzy architecture for real-time applications

NASA Technical Reports Server (NTRS)

Ramamoorthy, P. A.; Huang, Song

1992-01-01

Neural networks and fuzzy expert systems perform the same task of functional mapping using entirely different approaches. Each approach has certain unique features. The ability to learn specific input-output mappings from large input/output data possibly corrupted by noise and the ability to adapt or continue learning are some important features of neural networks. Fuzzy expert systems are known for their ability to deal with fuzzy information and incomplete/imprecise data in a structured, logical way. Since both of these techniques implement the same task (that of functional mapping--we regard 'inferencing' as one specific category under this class), a fusion of the two concepts that retains their unique features while overcoming their individual drawbacks will have excellent applications in the real world. In this paper, we arrive at a new architecture by fusing the two concepts. The architecture has the trainability/adaptibility (based on input/output observations) property of the neural networks and the architectural features that are unique to fuzzy expert systems. It also does not require specific information such as fuzzy rules, defuzzification procedure used, etc., though any such information can be integrated into the architecture. We show that this architecture can provide better performance than is possible from a single two or three layer feedforward neural network. Further, we show that this new architecture can be used as an efficient vehicle for hardware implementation of complex fuzzy expert systems for real-time applications. A numerical example is provided to show the potential of this approach.

Eye movements: The past 25 years

PubMed Central

Kowler, Eileen

2011-01-01

This article reviews the past 25 of research on eye movements (1986–2011). Emphasis is on three oculomotor behaviors: gaze control, smooth pursuit and saccades, and on their interactions with vision. Focus over the past 25 years has remained on the fundamental and classical questions: What are the mechanisms that keep gaze stable with either stationary or moving targets? How does the motion of the image on the retina affect vision? Where do we look – and why – when performing a complex task? How can the world appear clear and stable despite continual movements of the eyes? The past 25 years of investigation of these questions has seen progress and transformations at all levels due to new approaches (behavioral, neural and theoretical) aimed at studying how eye movements cope with real-world visual and cognitive demands. The work has led to a better understanding of how prediction, learning and attention work with sensory signals to contribute to the effective operation of eye movements in visually rich environments. PMID:21237189

How To Work and Live in the Real World: Basic Steps for Youth with Handicaps and Their Parents and Teachers.

ERIC Educational Resources Information Center

Patton, Patricia L.; And Others

This booklet is for young people with handicaps who are getting ready to graduate from high school and begin working and living in the adult world, with special focus on individuals with cultural differences. The booklet provides advice on completing preliminary, essential tasks of adult living. It also explains the services of various agencies…

A Practical Measure for the Complexity of Evolving Seismicity Patterns

NASA Astrophysics Data System (ADS)

Goltz, C.

2005-12-01

Earthquakes are a "complex" phenomenon. There is, however, no clear definition of what complexity actually is. Yet, it is important to distinguish between what is merely complicated and what is complex in the sense that simple rules can give rise to very rich behaviour. Seismicity is certainly a complicated phenomenon (difficult to understand) but simple models such as cellular automata indicate that earthquakes are truly complex. From the observational point of view, there exists the problem of quantification of complexity in real world seismicity patterns. Such a measurement is desirable, not only for fundamental understanding but also for monitoring and possibly for forecasting. Maybe the most workable definitions of complexity exist in informatics, summarised under the topic of algorithmic complexity. Here, after introducing the concepts, I apply such a measure of complexity to temporally evolving real-world seismicity patterns. Finally, I discuss the usefulness of the approach and regard the results in view of the occurrence of large earthquakes.

Training in Goal-Oriented Attentional Self-Regulation Improves Executive Functioning in Veterans with Chronic TBI.

PubMed

Novakovic-Agopian, Tatjana; Kornblith, Erica S; Abrams, Gary; Burciaga-Rosales, Joaquin; Loya, Fred; D'Esposito, Mark; Chen, Anthony J-W

2018-05-02

Deficits in executive control functions are some of the most common and disabling consequences of both military and civilian brain injury. However, effective interventions are scant. The goal of this study was to assess whether cognitive rehabilitation training that was successfully applied in chronic civilian brain injury would be effective for military Veterans with TBI. In a prior study, participants with chronic acquired brain injury significantly improved after training in goal-oriented attentional self-regulation (GOALS) on measures of attention/executive function, functional task performance, and goal-directed control over neural processing on fMRI. The objective of this study was to assess effects of GOALS training in Veterans with chronic TBI. 33 Veterans with chronic TBI and executive difficulties in their daily life completed either five weeks of manualized Goal-Oriented Attentional Self-Regulation (GOALS) training or Brain-Health Education (BHE) matched in time and intensity. Evaluator-blinded assessments at baseline and post training included neuropsychological and complex functional task performance and self-report measures of emotional regulation. After GOALS, but not BHE training, participants significantly improved from baseline on primary outcome measures of: Overall Complex Attention/Executive Function composite neuropsychological performance score [F = 7.10, p =.01; partial 2 = .19], and on overall complex functional task performance (Goal Processing Scale Overall Performance) [F=6.92, p=.01, partial 2 =.20]. Additionally, post-GOALS participants indicated significant improvement on emotional regulation self-report measures [POMS Confusion Score F=6.05, p=.02, partial2=.20]. Training in attentional self-regulation applied to participant defined goals may improve cognitive functioning in Veterans with chronic TBI. Attention regulation training may not only impact executive control functioning in real world complex tasks, but may also improve emotional regulation and functioning. Implications for treatment of Veterans with TBI are discussed.

More stereotypes, please! The limits of 'theory of mind' and the need for further studies on the complexity of real world social interactions.

PubMed

Andrews, Kristin

2017-01-01

I suggest that the Stereotype Rationality Hypothesis (Jussim 2012) is only partially right. I agree it is rational to rely on stereotypes, but in the complexity of real world social interactions, most of our individuating information invokes additional stereotypes. Despite assumptions to the contrary, there is reason to think theory of mind is not accurate, and social psychology's denial of stereotype accuracy led us toward mindreading/theory of mind - a less accurate account of how we understand other people.

Interactive entity resolution in relational data: a visual analytic tool and its evaluation.

PubMed

Kang, Hyunmo; Getoor, Lise; Shneiderman, Ben; Bilgic, Mustafa; Licamele, Louis

2008-01-01

Databases often contain uncertain and imprecise references to real-world entities. Entity resolution, the process of reconciling multiple references to underlying real-world entities, is an important data cleaning process required before accurate visualization or analysis of the data is possible. In many cases, in addition to noisy data describing entities, there is data describing the relationships among the entities. This relational data is important during the entity resolution process; it is useful both for the algorithms which determine likely database references to be resolved and for visual analytic tools which support the entity resolution process. In this paper, we introduce a novel user interface, D-Dupe, for interactive entity resolution in relational data. D-Dupe effectively combines relational entity resolution algorithms with a novel network visualization that enables users to make use of an entity's relational context for making resolution decisions. Since resolution decisions often are interdependent, D-Dupe facilitates understanding this complex process through animations which highlight combined inferences and a history mechanism which allows users to inspect chains of resolution decisions. An empirical study with 12 users confirmed the benefits of the relational context visualization on the performance of entity resolution tasks in relational data in terms of time as well as users' confidence and satisfaction.

Learning viewpoint invariant object representations using a temporal coherence principle.

PubMed

Einhäuser, Wolfgang; Hipp, Jörg; Eggert, Julian; Körner, Edgar; König, Peter

2005-07-01

Invariant object recognition is arguably one of the major challenges for contemporary machine vision systems. In contrast, the mammalian visual system performs this task virtually effortlessly. How can we exploit our knowledge on the biological system to improve artificial systems? Our understanding of the mammalian early visual system has been augmented by the discovery that general coding principles could explain many aspects of neuronal response properties. How can such schemes be transferred to system level performance? In the present study we train cells on a particular variant of the general principle of temporal coherence, the "stability" objective. These cells are trained on unlabeled real-world images without a teaching signal. We show that after training, the cells form a representation that is largely independent of the viewpoint from which the stimulus is looked at. This finding includes generalization to previously unseen viewpoints. The achieved representation is better suited for view-point invariant object classification than the cells' input patterns. This property to facilitate view-point invariant classification is maintained even if training and classification take place in the presence of an--also unlabeled--distractor object. In summary, here we show that unsupervised learning using a general coding principle facilitates the classification of real-world objects, that are not segmented from the background and undergo complex, non-isomorphic, transformations.

Comprehensive two-dimensional liquid chromatography for polyphenol analysis in foodstuffs.

PubMed

Cacciola, Francesco; Farnetti, Sara; Dugo, Paola; Marriott, Philip John; Mondello, Luigi

2017-01-01

Polyphenols are a class of plant secondary metabolites that are recently drawing a special interest because of their broad spectrum of pharmacological effects. As they are characterized by an enormous structural variability, the identification of these molecules in food samples is a difficult task, and sometimes having only a limited number of commercially available reference materials is not of great help. One-dimensional liquid chromatography is the most widely applied analytical approach for their analysis. In particular, the hyphenation of liquid chromatography to mass spectrometry has come to play an influential role by allowing relatively fast tentative identification and accurate quantification of polyphenolic compounds at trace levels in vegetable media. However, when dealing with very complex real-world food samples, a single separation system often does not provide sufficient resolving power for attaining rewarding results. Comprehensive two-dimensional liquid chromatography is a technique of great analytical impact, since it offers much higher peak capacities than separations in a single dimension. In the present review, we describe applications in the field of comprehensive two-dimensional liquid chromatography for polyphenol analysis in real-world food samples. Comprehensive two-dimensional liquid chromatography applications to nonfood matrices fall outside the scope of the current report and will not be discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of field-of-view restrictions on speed and accuracy of manoeuvring.

PubMed

Toet, Alexander; Jansen, Sander E M; Delleman, Nico J

2007-12-01

Effects of field-of-view restrictions on the speed and accuracy of participants performing a real-world manoeuvring task through an obstacled environment were investigated. Although field-of-view restrictions are known to affect human behaviour and to degrade performance for a range of different tasks, the relationship between human manoeuvring performance and field-of-view size is not known. This knowledge is essential to evaluate a trade-off between human performance, cost, and ergonomic aspects of field-of-view limiting devises like head-mounted displays and night vision goggles which are frequently deployed for tasks involving human motion through environments with obstacles. In this study the speed and accuracy of movement were measured in 15 participants (8 men, 7 women, 22.9 +/- 2.8 yr. of age) traversing a course formed by three wall segments for different field-of-view restrictions. Analysis showed speed decreased linearly with decreasing field-of-view extent, while accuracy was consistently reduced for all restricted field-of-view conditions. Present results may be used to evaluate cost and performance trade-offs for field-of-view restricting devices deployed to perform time-limited human-locomotion tasks in complex structured environments, such as night-vision goggles and head-mounted displays.

Computer Training for the Real World.

ERIC Educational Resources Information Center

American School and University, 1981

1981-01-01

Hull High School in suburban Boston (Massachusetts) is rated as one of the top 10 secondary schools in the country offering a computer education program. The same computers used by the students are shared by school officials for administrative tasks. (Author/MLF)

Gamification of Clinical Routine: The Dr. Fill Approach.

PubMed

Bukowski, Mark; Kühn, Martin; Zhao, Xiaoqing; Bettermann, Ralf; Jonas, Stephan

2016-01-01

Gamification is used in clinical context in the health care education. Furthermore, it has shown great promises to improve the performance of the health care staff in their daily routine. In this work we focus on the medication sorting task, which is performed manually in hospitals. This task is very error prone and needs to be performed daily. Nevertheless, errors in the medication are crucial and lead to serious complications. In this work we present a real world gamification approach of the medication sorting task in a patient's daily pill organizer. The player of the game needs to sort the correct medication into the correct dispenser slots and is rewarded or punished in real time. At the end of the game, a score is given and the user can register in a leaderboard.

Investigating the Relationships between a Reading Test and Can-Do Statements of Performance on Reading Tasks

ERIC Educational Resources Information Center

Liu, Hsin-min

2014-01-01

One of the fundamental problems in language testing is the lack of adequate generalizability between what a test is measuring and what fulfills the learners' real world language use needs. It is important to recognize that no matter how precise a test measures a construct, if the way that a construct is defined and the way that test tasks are…

Inattentional blindness for a gun during a simulated police vehicle stop.

PubMed

Simons, Daniel J; Schlosser, Michael D

2017-01-01

People often fail to notice unexpected objects and events when they are focusing attention on something else. Most studies of this "inattentional blindness" use unexpected objects that are irrelevant to the primary task and to the participant (e.g., gorillas in basketball games or colored shapes in computerized tracking tasks). Although a few studies have examined noticing rates for personally relevant or task-relevant unexpected objects, few have done so in a real-world context with objects that represent a direct threat to the participant. In this study, police academy trainees (n = 100) and experienced police officers (n = 75) engaged in a simulated vehicle traffic stop in which they approached a vehicle to issue a warning or citation for running a stop sign. The driver was either passive and cooperative or agitated and hostile when complying with the officer's instructions. Overall, 58% of the trainees and 33% of the officers failed to notice a gun positioned in full view on the passenger dashboard. The driver's style of interaction had little effect on noticing rates for either group. People can experience inattentional blindness for a potentially dangerous object in a naturalistic real-world context, even when noticing that object would change how they perform their primary task and even when their training focuses on awareness of potential threats.

CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: The Fractal Dimensions of Complex Networks

NASA Astrophysics Data System (ADS)

Guo, Long; Cai, XU

2009-08-01

It is shown that many real complex networks share distinctive features, such as the small-world effect and the heterogeneous property of connectivity of vertices, which are different from random networks and regular lattices. Although these features capture the important characteristics of complex networks, their applicability depends on the style of networks. To unravel the universal characteristics many complex networks have in common, we study the fractal dimensions of complex networks using the method introduced by Shanker. We find that the average 'density' (ρ(r)) of complex networks follows a better power-law function as a function of distance r with the exponent df, which is defined as the fractal dimension, in some real complex networks. Furthermore, we study the relation between df and the shortcuts Nadd in small-world networks and the size N in regular lattices. Our present work provides a new perspective to understand the dependence of the fractal dimension df on the complex network structure.

Decision-making deficits in normal elderly persons associated with executive personality disturbances.

PubMed

Nguyen, Christopher M; Barrash, Joseph; Koenigs, Anna L; Bechara, Antoine; Tranel, Daniel; Denburg, Natalie L

2013-11-01

The problems that some community-dwelling elderly persons develop in real-world decision-making may have disastrous consequences for their health and financial well-being. Investigations across the adult life span have identified personality as an important individual differences variable that is related to decision-making ability. The aim of this study was to investigate the relationship between personality characteristics, as rated by an informant, and complex decision-making performance among elderly persons. It was hypothesized that deficits in decision-making would be associated with personality characteristics reflecting weak executive functioning (Lack of Planning, Poor Judgment, Lack of Persistence, Perseveration, Lack of Initiative, Impulsivity, and Indecisiveness). Fifty-eight elderly persons participated. Their health and cognitive status were deemed intact via comprehensive neuropsychological evaluation. The Iowa Scales of Personality, completed by an informant, was used to assess personality characteristics, and the Iowa Gambling Task, completed by the participant, was used to assess complex decision-making abilities. Longstanding disturbances in executive personality characteristics were found to be associated with poor decision-making, and these disturbances remained predictive of poor decision-making even after taking into consideration demographic, neuropsychological, and mood factors. Acquired personality disturbances did not add significantly to prediction after longstanding disturbances were taken into account. Disturbances in other dimensions of personality were not significantly associated with poor decision-making. Our study suggests that attentiveness to the personality correlates of difficulties with aspects of executive functioning over the adult years could enhance the ability to identify older individuals at risk for problems with real-world decision-making.

Decision-Making Deficits in Normal Elderly Persons Associated with Executive Personality Disturbances

PubMed Central

Nguyen, Christopher M.; Barrash, Joseph; Koenigs, Anna L.; Bechara, Antoine; Tranel, Daniel; Denburg, Natalie L.

2014-01-01

Background The problems that some community-dwelling elderly develop in real-world decision-making may have disastrous consequences for their health and financial well-being. Investigations across the adult life span have identified personality as an important individual differences variable that is related to decision-making ability. The aim of this study was to investigate the relationship between personality characteristics, as rated by an informant, and complex decision-making performance among elders. It was hypothesized that deficits in decision-making would be associated with personality characteristics reflecting weak executive functioning (Lack of Planning, Poor Judgment, Lack of Persistence, Perseveration, Lack of Initiative, Impulsivity, and Indecisiveness). Methods Fifty-eight elderly persons participated. Their health and cognitive status were deemed intact via comprehensive neuropsychological evaluation. The Iowa Scales of Personality, completed by an informant, was used to assess personality characteristics, and the Iowa Gambling Task, completed by the participant, was used to assess complex decision-making abilities. Results Longstanding disturbances in executive personality characteristics were found to be associated with poor decision-making, and these disturbances remained predictive of poor decision-making even after taking into consideration demographic, neuropsychological, and mood factors. Acquired personality disturbances did not add significantly to prediction after longstanding disturbances were taken into account. Disturbances in other dimensions of personality were not significantly associated with poor decision-making. Conclusions Our study suggests that attentiveness to the personality correlates of difficulties with aspects of executive functioning over the adult years could enhance the ability to identify older individuals at risk for problems with real-world decision-making. PMID:23906413

Identifying important nodes by adaptive LeaderRank

NASA Astrophysics Data System (ADS)

Xu, Shuang; Wang, Pei

2017-03-01

Spreading process is a common phenomenon in complex networks. Identifying important nodes in complex networks is of great significance in real-world applications. Based on the spreading process on networks, a lot of measures have been proposed to evaluate the importance of nodes. However, most of the existing measures are appropriate to static networks, which are fragile to topological perturbations. Many real-world complex networks are dynamic rather than static, meaning that the nodes and edges of such networks may change with time, which challenge numerous existing centrality measures. Based on a new weighted mechanism and the newly proposed H-index and LeaderRank (LR), this paper introduces a variant of the LR measure, called adaptive LeaderRank (ALR), which is a new member of the LR-family. Simulations on six real-world networks reveal that the new measure can well balance between prediction accuracy and robustness. More interestingly, the new measure can better adapt to the adjustment or local perturbations of network topologies, as compared with the existing measures. By discussing the detailed properties of the measures from the LR-family, we illustrate that the ALR has its competitive advantages over the other measures. The proposed algorithm enriches the measures to understand complex networks, and may have potential applications in social networks and biological systems.

The Role of Strategy Knowledge for the Application of Strategies in Complex Problem Solving Tasks

ERIC Educational Resources Information Center

Wüstenberg, Sascha; Stadler, Matthias; Hautamäki, Jarkko; Greiff, Samuel

2014-01-01

Education in the twenty-first century must prepare students to meet the challenges of a dynamic and interconnected world. However, assessment of students' skills tends to focus primarily on static tasks. Therefore, it is not known whether knowledge about successful strategies displayed on static tasks can be transferred to interactive and dynamic…

Improving wavelet denoising based on an in-depth analysis of the camera color processing

NASA Astrophysics Data System (ADS)

Seybold, Tamara; Plichta, Mathias; Stechele, Walter

2015-02-01

While Denoising is an extensively studied task in signal processing research, most denoising methods are designed and evaluated using readily processed image data, e.g. the well-known Kodak data set. The noise model is usually additive white Gaussian noise (AWGN). This kind of test data does not correspond to nowadays real-world image data taken with a digital camera. Using such unrealistic data to test, optimize and compare denoising algorithms may lead to incorrect parameter tuning or suboptimal choices in research on real-time camera denoising algorithms. In this paper we derive a precise analysis of the noise characteristics for the different steps in the color processing. Based on real camera noise measurements and simulation of the processing steps, we obtain a good approximation for the noise characteristics. We further show how this approximation can be used in standard wavelet denoising methods. We improve the wavelet hard thresholding and bivariate thresholding based on our noise analysis results. Both the visual quality and objective quality metrics show the advantage of the proposed method. As the method is implemented using look-up-tables that are calculated before the denoising step, our method can be implemented with very low computational complexity and can process HD video sequences real-time in an FPGA.

Pre-Service Teachers' Views of the Maths Talent Quest (MTQ): Connecting Mathematical Concepts to Everyday Tasks and Experiences

ERIC Educational Resources Information Center

Baum, Prudence; Perera, Radhika

2017-01-01

Mathematics needs to take on a real-world quality, and students need to be able to identify and connect the value of what they are learning within the classroom to life outside the classroom. Creating a connection between the mathematics learned within a classroom and its value to life in the outside world is critical to effectively engage…

Automatic guidance of attention during real-world visual search

PubMed Central

Seidl-Rathkopf, Katharina N.; Turk-Browne, Nicholas B.; Kastner, Sabine

2015-01-01

Looking for objects in cluttered natural environments is a frequent task in everyday life. This process can be difficult, as the features, locations, and times of appearance of relevant objects are often not known in advance. A mechanism by which attention is automatically biased toward information that is potentially relevant may thus be helpful. Here we tested for such a mechanism across five experiments by engaging participants in real-world visual search and then assessing attentional capture for information that was related to the search set but was otherwise irrelevant. Isolated objects captured attention while preparing to search for objects from the same category embedded in a scene, as revealed by lower detection performance (Experiment 1A). This capture effect was driven by a central processing bottleneck rather than the withdrawal of spatial attention (Experiment 1B), occurred automatically even in a secondary task (Experiment 2A), and reflected enhancement of matching information rather than suppression of non-matching information (Experiment 2B). Finally, attentional capture extended to objects that were semantically associated with the target category (Experiment 3). We conclude that attention is efficiently drawn towards a wide range of information that may be relevant for an upcoming real-world visual search. This mechanism may be adaptive, allowing us to find information useful for our behavioral goals in the face of uncertainty. PMID:25898897

Biological Visualization, Imaging and Simulation(Bio-VIS) at NASA Ames Research Center: Developing New Software and Technology for Astronaut Training and Biology Research in Space

NASA Technical Reports Server (NTRS)

Smith, Jeffrey

2003-01-01

The Bio- Visualization, Imaging and Simulation (BioVIS) Technology Center at NASA's Ames Research Center is dedicated to developing and applying advanced visualization, computation and simulation technologies to support NASA Space Life Sciences research and the objectives of the Fundamental Biology Program. Research ranges from high resolution 3D cell imaging and structure analysis, virtual environment simulation of fine sensory-motor tasks, computational neuroscience and biophysics to biomedical/clinical applications. Computer simulation research focuses on the development of advanced computational tools for astronaut training and education. Virtual Reality (VR) and Virtual Environment (VE) simulation systems have become important training tools in many fields from flight simulation to, more recently, surgical simulation. The type and quality of training provided by these computer-based tools ranges widely, but the value of real-time VE computer simulation as a method of preparing individuals for real-world tasks is well established. Astronauts routinely use VE systems for various training tasks, including Space Shuttle landings, robot arm manipulations and extravehicular activities (space walks). Currently, there are no VE systems to train astronauts for basic and applied research experiments which are an important part of many missions. The Virtual Glovebox (VGX) is a prototype VE system for real-time physically-based simulation of the Life Sciences Glovebox where astronauts will perform many complex tasks supporting research experiments aboard the International Space Station. The VGX consists of a physical display system utilizing duel LCD projectors and circular polarization to produce a desktop-sized 3D virtual workspace. Physically-based modeling tools (Arachi Inc.) provide real-time collision detection, rigid body dynamics, physical properties and force-based controls for objects. The human-computer interface consists of two magnetic tracking devices (Ascention Inc.) attached to instrumented gloves (Immersion Inc.) which co-locate the user's hands with hand/forearm representations in the virtual workspace. Force-feedback is possible in a work volume defined by a Phantom Desktop device (SensAble inc.). Graphics are written in OpenGL. The system runs on a 2.2 GHz Pentium 4 PC. The prototype VGX provides astronauts and support personnel with a real-time physically-based VE system to simulate basic research tasks both on Earth and in the microgravity of Space. The immersive virtual environment of the VGX also makes it a useful tool for virtual engineering applications including CAD development, procedure design and simulation of human-system systems in a desktop-sized work volume.

Disruption in neural phase synchrony is related to identification of inattentional deafness in real-world setting.

PubMed

Callan, Daniel E; Gateau, Thibault; Durantin, Gautier; Gonthier, Nicolas; Dehais, Frédéric

2018-06-01

Individuals often have reduced ability to hear alarms in real world situations (e.g., anesthesia monitoring, flying airplanes) when attention is focused on another task, sometimes with devastating consequences. This phenomenon is called inattentional deafness and usually occurs under critical high workload conditions. It is difficult to simulate the critical nature of these tasks in the laboratory. In this study, dry electroencephalography is used to investigate inattentional deafness in real flight while piloting an airplane. The pilots participating in the experiment responded to audio alarms while experiencing critical high workload situations. It was found that missed relative to detected alarms were marked by reduced stimulus evoked phase synchrony in theta and alpha frequencies (6-14 Hz) from 120 to 230 ms poststimulus onset. Correlation of alarm detection performance with intertrial coherence measures of neural phase synchrony showed different frequency and time ranges for detected and missed alarms. These results are consistent with selective attentional processes actively disrupting oscillatory coherence in sensory networks not involved with the primary task (piloting in this case) under critical high load conditions. This hypothesis is corroborated by analyses of flight parameters showing greater maneuvering associated with difficult phases of flight occurring during missed alarms. Our results suggest modulation of neural oscillation is a general mechanism of attention utilizing enhancement of phase synchrony to sharpen alarm perception during successful divided attention, and disruption of phase synchrony in brain networks when attentional demands of the primary task are great, such as in the case of inattentional deafness. © 2018 Wiley Periodicals, Inc.

Bayesian Inference of Natural Rankings in Incomplete Competition Networks

PubMed Central

Park, Juyong; Yook, Soon-Hyung

2014-01-01

Competition between a complex system's constituents and a corresponding reward mechanism based on it have profound influence on the functioning, stability, and evolution of the system. But determining the dominance hierarchy or ranking among the constituent parts from the strongest to the weakest – essential in determining reward and penalty – is frequently an ambiguous task due to the incomplete (partially filled) nature of competition networks. Here we introduce the “Natural Ranking,” an unambiguous ranking method applicable to a round robin tournament, and formulate an analytical model based on the Bayesian formula for inferring the expected mean and error of the natural ranking of nodes from an incomplete network. We investigate its potential and uses in resolving important issues of ranking by applying it to real-world competition networks. PMID:25163528

Data-driven coarse graining in action: Modeling and prediction of complex systems

NASA Astrophysics Data System (ADS)

Krumscheid, S.; Pradas, M.; Pavliotis, G. A.; Kalliadasis, S.

2015-10-01

In many physical, technological, social, and economic applications, one is commonly faced with the task of estimating statistical properties, such as mean first passage times of a temporal continuous process, from empirical data (experimental observations). Typically, however, an accurate and reliable estimation of such properties directly from the data alone is not possible as the time series is often too short, or the particular phenomenon of interest is only rarely observed. We propose here a theoretical-computational framework which provides us with a systematic and rational estimation of statistical quantities of a given temporal process, such as waiting times between subsequent bursts of activity in intermittent signals. Our framework is illustrated with applications from real-world data sets, ranging from marine biology to paleoclimatic data.

Engineering scalable biological systems

PubMed Central

2010-01-01

Synthetic biology is focused on engineering biological organisms to study natural systems and to provide new solutions for pressing medical, industrial and environmental problems. At the core of engineered organisms are synthetic biological circuits that execute the tasks of sensing inputs, processing logic and performing output functions. In the last decade, significant progress has been made in developing basic designs for a wide range of biological circuits in bacteria, yeast and mammalian systems. However, significant challenges in the construction, probing, modulation and debugging of synthetic biological systems must be addressed in order to achieve scalable higher-complexity biological circuits. Furthermore, concomitant efforts to evaluate the safety and biocontainment of engineered organisms and address public and regulatory concerns will be necessary to ensure that technological advances are translated into real-world solutions. PMID:21468204

Temporal trade-offs in psychophysics.

PubMed

Barack, David L; Gold, Joshua I

2016-04-01

Psychophysical techniques typically assume straightforward relationships between manipulations of real-world events, their effects on the brain, and behavioral reports of those effects. However, these relationships can be influenced by many complex, strategic factors that contribute to task performance. Here we discuss several of these factors that share two key features. First, they involve subjects making flexible use of time to process information. Second, this flexibility can reflect the rational regulation of information-processing trade-offs that can play prominent roles in particular temporal epochs: sensitivity to stability versus change for past information, speed versus accuracy for current information, and exploitation versus exploration for future goals. Understanding how subjects manage these trade-offs can be used to help design and interpret psychophysical studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bayesian Inference of Natural Rankings in Incomplete Competition Networks

NASA Astrophysics Data System (ADS)

Park, Juyong; Yook, Soon-Hyung

2014-08-01

Competition between a complex system's constituents and a corresponding reward mechanism based on it have profound influence on the functioning, stability, and evolution of the system. But determining the dominance hierarchy or ranking among the constituent parts from the strongest to the weakest - essential in determining reward and penalty - is frequently an ambiguous task due to the incomplete (partially filled) nature of competition networks. Here we introduce the ``Natural Ranking,'' an unambiguous ranking method applicable to a round robin tournament, and formulate an analytical model based on the Bayesian formula for inferring the expected mean and error of the natural ranking of nodes from an incomplete network. We investigate its potential and uses in resolving important issues of ranking by applying it to real-world competition networks.

Predicting links based on knowledge dissemination in complex network

NASA Astrophysics Data System (ADS)

Zhou, Wen; Jia, Yifan

2017-04-01

Link prediction is the task of mining the missing links in networks or predicting the next vertex pair to be connected by a link. A lot of link prediction methods were inspired by evolutionary processes of networks. In this paper, a new mechanism for the formation of complex networks called knowledge dissemination (KD) is proposed with the assumption of knowledge disseminating through the paths of a network. Accordingly, a new link prediction method-knowledge dissemination based link prediction (KDLP)-is proposed to test KD. KDLP characterizes vertex similarity based on knowledge quantity (KQ) which measures the importance of a vertex through H-index. Extensive numerical simulations on six real-world networks demonstrate that KDLP is a strong link prediction method which performs at a higher prediction accuracy than four well-known similarity measures including common neighbors, local path index, average commute time and matrix forest index. Furthermore, based on the common conclusion that an excellent link prediction method reveals a good evolving mechanism, the experiment results suggest that KD is a considerable network evolving mechanism for the formation of complex networks.

Real-time feedback on knee abduction moment does not improve frontal-plane knee mechanics during jump landings.

PubMed

Beaulieu, M L; Palmieri-Smith, R M

2014-08-01

Excessive knee abduction loading is a contributing factor to anterior cruciate ligament (ACL) injury risk. The purpose of this study was to determine whether a double-leg landing training program with real-time visual feedback improves frontal-plane mechanics during double- and single-leg landings. Knee abduction angles and moments and vertical ground reaction forces (GRF) of 21 recreationally active women were quantified for double- and single-leg landings before and after the training program. This program consisted of two sessions of double-leg jump landings with real-time visual feedback on knee abduction moments for the experimental group and without real-time feedback for the control group. No significant differences were found between training groups. In comparison with pre-training data, peak knee abduction moments decreased 12% post-training for both double- and single-leg landings; whereas peak vertical GRF decreased 8% post-training for double-leg landings only, irrespective of training group. Real-time feedback on knee abduction moments, therefore, did not significantly improve frontal-plane knee mechanics during landings. The effect of the training program on knee abduction moments, however, transferred from the double-leg landings (simple task) to single-leg landings (more complex task). Consequently, ACL injury prevention efforts may not need to focus on complex tasks during which injury occurs. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Dependable Real-Time Systems

DTIC Science & Technology

1991-09-30

0196 or 413 545-0720 PI E-mail Address: krithi@nirvan.cs.umass.edu, stankovic(ocs.umass.edu Grant or Contract Title: Dependable Real - Time Systems Grant...Dependable Real - Time Systems " Grant or Contract Number: N00014-85-k-0398 L " Reporting Period: 1 Oct 87 - 30 Sep 91 , 2. Summary of Accomplishments ’ 2.1 Our...in developing a sound approach to scheduling tasks in complex real - time systems , (2) developed a real-time operating system kernel, a preliminary

Stability and Workload of the Virtual Reality-Based Simulator-2.

PubMed

Kamaraj, Deepan C; Dicianno, Brad E; Mahajan, Harshal P; Buhari, Alhaji M; Cooper, Rory A

2016-07-01

To assess the stability of clinicians' and users' rating of electric-powered wheelchair (EPW) driving while using 4 different human-machine interfaces (HMIs) within the Virtual Reality-based SIMulator-version 2 (VRSIM-2) and in the real world (accounting for a total of 5 unique driving conditions). Within-subjects repeated-measures design. Simulation-based assessment in a research laboratory. A convenience sample of EPW athletes (N=21) recruited at the 31st National Veterans Wheelchair Games. Not applicable. Composite PMRT scores from the Power Mobility Road Test (PMRT); Raw Task Load Index; and the 6 subscale scores from the Task Load Index developed by the National Aeronautics and Space Administration (NASA-TLX). There was moderate stability (intraclass correlation coefficient between .50 and .75) in the total composite PMRT scores (P<.001) and the users' self-reported performance scores (P<.001) among the 5 driving conditions. There was a significant difference in the workload among the 5 different driving conditions as reflected by the Raw Task Load Index (P=.009). Subanalyses revealed this difference was due to the difference in the mental demand (P=.007) and frustration (P=.007) subscales. Post hoc analyses revealed that these differences in the NASA-TLX subscale scores were due to the differences between real-world and virtual driving scores, particularly attributable to the conditions (1 and 3) that lacked the rollers as a part of the simulation. Further design improvements in the simulator to increase immersion experienced by the EPW user, along with a standardized training program for clinicians to deliver PMRT in VRSIM-2, could improve the stability between the different HMIs and real-world driving. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Everyday episodic memory in amnestic mild cognitive impairment: a preliminary investigation

PubMed Central

2011-01-01

Background Decline in episodic memory is one of the hallmark features of Alzheimer's disease (AD) and is also a defining feature of amnestic Mild Cognitive Impairment (MCI), which is posited as a potential prodrome of AD. While deficits in episodic memory are well documented in MCI, the nature of this impairment remains relatively under-researched, particularly for those domains with direct relevance and meaning for the patient's daily life. In order to fully explore the impact of disruption to the episodic memory system on everyday memory in MCI, we examined participants' episodic memory capacity using a battery of experimental tasks with real-world relevance. We investigated episodic acquisition and delayed recall (story-memory), associative memory (face-name pairings), spatial memory (route learning and recall), and memory for everyday mundane events in 16 amnestic MCI and 18 control participants. Furthermore, we followed MCI participants longitudinally to gain preliminary evidence regarding the possible predictive efficacy of these real-world episodic memory tasks for subsequent conversion to AD. Results The most discriminating tests at baseline were measures of acquisition, delayed recall, and associative memory, followed by everyday memory, and spatial memory tasks, with MCI patients scoring significantly lower than controls. At follow-up (mean time elapsed: 22.4 months), 6 MCI cases had progressed to clinically probable AD. Exploratory logistic regression analyses revealed that delayed associative memory performance at baseline was a potential predictor of subsequent conversion to AD. Conclusions As a preliminary study, our findings suggest that simple associative memory paradigms with real-world relevance represent an important line of enquiry in future longitudinal studies charting MCI progression over time. PMID:21816065

Driving performance of stable outpatients with depression undergoing real-world treatment.

PubMed

Miyata, Akemi; Iwamoto, Kunihiro; Kawano, Naoko; Aleksic, Branko; Ando, Masahiko; Ebe, Kazutoshi; Fujita, Kiyoshi; Yokoyama, Motonori; Akiyama, Tsuyoshi; Igarashi, Yoshio; Ozaki, Norio

2018-06-01

Although the effects of psychotropics on driving ability have received much attention, little research is available on driving performance of stable outpatients with depression undergoing real-world treatment. This observational study investigated driving performance, cognitive functions, and depressive symptomatology of partly remitted outpatients with depression under daily-practice psychopharmacologic treatment. Seventy stable outpatients with depression and 67 healthy volunteers were enrolled. Patients' prescriptions were not controlled in order to capture the real-world treatment environment. Participants underwent three driving tasks - road-tracking, car-following, and harsh-braking - using a driving simulator, and three cognitive tasks - Continuous Performance Test, Wisconsin Card Sorting Test, and Trail-Making Test. The Symptom Assessment Scale - Structured Interview Guide for the Hamilton Depression Rating Scale, Beck Depression Inventory-II, Social Adaptation Self-Evaluation Scale, and Stanford Sleepiness Scale were also completed. Although many patients received various pharmacologic treatments, there were no significant differences in the three driving tasks between outpatients with depression and healthy controls. Difficulty of maintaining set in the Wisconsin Card Sorting Test was significantly increased in patients with depression. Results on the Social Adaptation Self-Evaluation Scale were significantly associated with road-tracking and car-following performance, in contrast to results on the Hamilton Depression Rating Scale and the Beck Depression Inventory-II. We conclude that partly remitted depressive patients under steady-state pharmacologic treatment do not differ from healthy controls with respect to driving performance, which seems to be more affected by psychosocial functioning than by pharmacologic agents. This, however, should be investigated systematically in an off/on study. © 2018 The Authors. Psychiatry and Clinical Neurosciences © 2018 Japanese Society of Psychiatry and Neurology.

A Measure of Search Efficiency in a Real World Search Task (PREPRINT)

DTIC Science & Technology

2009-02-16

Search Task 5a. CONTRACT NUMBER N00173-08-1-G030 5b. GRANT NUMBER NRL BAA 08-09, 55-07-01 5c. PROGRAM ELEMENT NUMBER 0602782N 6. AUTHOR(S... Beck , Melissa R. Ph.D (LSU) Maura C. Lohrenz (NRL Code 7440.1) J. Gregory Trafton (NRL Code 5515) 5d. PROJECT NUMBER 08294 5e. TASK NUMBER... Beck 19b. TELEPHONE NUMBER (Include area code) (225)578-7214 Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 A measure of search

Attentional synchrony and the influence of viewing task on gaze behavior in static and dynamic scenes.

PubMed

Smith, Tim J; Mital, Parag K

2013-07-17

Does viewing task influence gaze during dynamic scene viewing? Research into the factors influencing gaze allocation during free viewing of dynamic scenes has reported that the gaze of multiple viewers clusters around points of high motion (attentional synchrony), suggesting that gaze may be primarily under exogenous control. However, the influence of viewing task on gaze behavior in static scenes and during real-world interaction has been widely demonstrated. To dissociate exogenous from endogenous factors during dynamic scene viewing we tracked participants' eye movements while they (a) freely watched unedited videos of real-world scenes (free viewing) or (b) quickly identified where the video was filmed (spot-the-location). Static scenes were also presented as controls for scene dynamics. Free viewing of dynamic scenes showed greater attentional synchrony, longer fixations, and more gaze to people and areas of high flicker compared with static scenes. These differences were minimized by the viewing task. In comparison with the free viewing of dynamic scenes, during the spot-the-location task fixation durations were shorter, saccade amplitudes were longer, and gaze exhibited less attentional synchrony and was biased away from areas of flicker and people. These results suggest that the viewing task can have a significant influence on gaze during a dynamic scene but that endogenous control is slow to kick in as initial saccades default toward the screen center, areas of high motion and people before shifting to task-relevant features. This default-like viewing behavior returns after the viewing task is completed, confirming that gaze behavior is more predictable during free viewing of dynamic than static scenes but that this may be due to natural correlation between regions of interest (e.g., people) and motion.

Modeling and simulation of dynamic ant colony's labor division for task allocation of UAV swarm

NASA Astrophysics Data System (ADS)

Wu, Husheng; Li, Hao; Xiao, Renbin; Liu, Jie

2018-02-01

The problem of unmanned aerial vehicle (UAV) task allocation not only has the intrinsic attribute of complexity, such as highly nonlinear, dynamic, highly adversarial and multi-modal, but also has a better practicability in various multi-agent systems, which makes it more and more attractive recently. In this paper, based on the classic fixed response threshold model (FRTM), under the idea of "problem centered + evolutionary solution" and by a bottom-up way, the new dynamic environmental stimulus, response threshold and transition probability are designed, and a dynamic ant colony's labor division (DACLD) model is proposed. DACLD allows a swarm of agents with a relatively low-level of intelligence to perform complex tasks, and has the characteristic of distributed framework, multi-tasks with execution order, multi-state, adaptive response threshold and multi-individual response. With the proposed model, numerical simulations are performed to illustrate the effectiveness of the distributed task allocation scheme in two situations of UAV swarm combat (dynamic task allocation with a certain number of enemy targets and task re-allocation due to unexpected threats). Results show that our model can get both the heterogeneous UAVs' real-time positions and states at the same time, and has high degree of self-organization, flexibility and real-time response to dynamic environments.

Musical Sophistication and the Effect of Complexity on Auditory Discrimination in Finnish Speakers.

PubMed

Dawson, Caitlin; Aalto, Daniel; Šimko, Juraj; Vainio, Martti; Tervaniemi, Mari

2017-01-01

Musical experiences and native language are both known to affect auditory processing. The present work aims to disentangle the influences of native language phonology and musicality on behavioral and subcortical sound feature processing in a population of musically diverse Finnish speakers as well as to investigate the specificity of enhancement from musical training. Finnish speakers are highly sensitive to duration cues since in Finnish, vowel and consonant duration determine word meaning. Using a correlational approach with a set of behavioral sound feature discrimination tasks, brainstem recordings, and a musical sophistication questionnaire, we find no evidence for an association between musical sophistication and more precise duration processing in Finnish speakers either in the auditory brainstem response or in behavioral tasks, but they do show an enhanced pitch discrimination compared to Finnish speakers with less musical experience and show greater duration modulation in a complex task. These results are consistent with a ceiling effect set for certain sound features which corresponds to the phonology of the native language, leaving an opportunity for music experience-based enhancement of sound features not explicitly encoded in the language (such as pitch, which is not explicitly encoded in Finnish). Finally, the pattern of duration modulation in more musically sophisticated Finnish speakers suggests integrated feature processing for greater efficiency in a real world musical situation. These results have implications for research into the specificity of plasticity in the auditory system as well as to the effects of interaction of specific language features with musical experiences.

Musical Sophistication and the Effect of Complexity on Auditory Discrimination in Finnish Speakers

PubMed Central

Dawson, Caitlin; Aalto, Daniel; Šimko, Juraj; Vainio, Martti; Tervaniemi, Mari

2017-01-01

Musical experiences and native language are both known to affect auditory processing. The present work aims to disentangle the influences of native language phonology and musicality on behavioral and subcortical sound feature processing in a population of musically diverse Finnish speakers as well as to investigate the specificity of enhancement from musical training. Finnish speakers are highly sensitive to duration cues since in Finnish, vowel and consonant duration determine word meaning. Using a correlational approach with a set of behavioral sound feature discrimination tasks, brainstem recordings, and a musical sophistication questionnaire, we find no evidence for an association between musical sophistication and more precise duration processing in Finnish speakers either in the auditory brainstem response or in behavioral tasks, but they do show an enhanced pitch discrimination compared to Finnish speakers with less musical experience and show greater duration modulation in a complex task. These results are consistent with a ceiling effect set for certain sound features which corresponds to the phonology of the native language, leaving an opportunity for music experience-based enhancement of sound features not explicitly encoded in the language (such as pitch, which is not explicitly encoded in Finnish). Finally, the pattern of duration modulation in more musically sophisticated Finnish speakers suggests integrated feature processing for greater efficiency in a real world musical situation. These results have implications for research into the specificity of plasticity in the auditory system as well as to the effects of interaction of specific language features with musical experiences. PMID:28450829

RoboCup-Rescue: an international cooperative research project of robotics and AI for the disaster mitigation problem

NASA Astrophysics Data System (ADS)

Tadokoro, Satoshi; Kitano, Hiroaki; Takahashi, Tomoichi; Noda, Itsuki; Matsubara, Hitoshi; Shinjoh, Atsushi; Koto, Tetsuo; Takeuchi, Ikuo; Takahashi, Hironao; Matsuno, Fumitoshi; Hatayama, Mitsunori; Nobe, Jun; Shimada, Susumu

2000-07-01

This paper introduces the RoboCup-Rescue Simulation Project, a contribution to the disaster mitigation, search and rescue problem. A comprehensive urban disaster simulator is constructed on distributed computers. Heterogeneous intelligent agents such as fire fighters, victims and volunteers conduct search and rescue activities in this virtual disaster world. A real world interface integrates various sensor systems and controllers of infrastructures in the real cities with the real world. Real-time simulation is synchronized with actual disasters, computing complex relationship between various damage factors and agent behaviors. A mission-critical man-machine interface provides portability and robustness of disaster mitigation centers, and augmented-reality interfaces for rescue in real disasters. It also provides a virtual- reality training function for the public. This diverse spectrum of RoboCup-Rescue contributes to the creation of the safer social system.

15-month-olds' transfer of learning between touch screen and real-world displays: language cues and cognitive loads.

PubMed

Zack, Elizabeth; Gerhardstein, Peter; Meltzoff, Andrew N; Barr, Rachel

2013-02-01

Infants have difficulty transferring information between 2D and 3D sources. The current study extends Zack, Barr, Gerhardstein, Dickerson & Meltzoff's (2009) touch screen imitation task to examine whether the addition of specific language cues significantly facilitates 15-month-olds' transfer of learning between touch screens and real-world 3D objects. The addition of two kinds of linguistic cues (object label plus verb or nonsense name) did not elevate action imitation significantly above levels observed when such language cues were not used. Language cues hindered infants' performance in the 3D→2D direction of transfer, but only for the object label plus verb condition. The lack of a facilitative effect of language is discussed in terms of competing cognitive loads imposed by conjointly transferring information across dimensions and processing linguistic cues in an action imitation task at this age. © 2012 The Authors. Scandinavian Journal of Psychology © 2012 The Scandinavian Psychological Associations.

Reinforcement Learning in Multidimensional Environments Relies on Attention Mechanisms

PubMed Central

Daniel, Reka; Geana, Andra; Gershman, Samuel J.; Leong, Yuan Chang; Radulescu, Angela; Wilson, Robert C.

2015-01-01

In recent years, ideas from the computational field of reinforcement learning have revolutionized the study of learning in the brain, famously providing new, precise theories of how dopamine affects learning in the basal ganglia. However, reinforcement learning algorithms are notorious for not scaling well to multidimensional environments, as is required for real-world learning. We hypothesized that the brain naturally reduces the dimensionality of real-world problems to only those dimensions that are relevant to predicting reward, and conducted an experiment to assess by what algorithms and with what neural mechanisms this “representation learning” process is realized in humans. Our results suggest that a bilateral attentional control network comprising the intraparietal sulcus, precuneus, and dorsolateral prefrontal cortex is involved in selecting what dimensions are relevant to the task at hand, effectively updating the task representation through trial and error. In this way, cortical attention mechanisms interact with learning in the basal ganglia to solve the “curse of dimensionality” in reinforcement learning. PMID:26019331

Reinforcement learning in multidimensional environments relies on attention mechanisms.

PubMed

Niv, Yael; Daniel, Reka; Geana, Andra; Gershman, Samuel J; Leong, Yuan Chang; Radulescu, Angela; Wilson, Robert C

2015-05-27

In recent years, ideas from the computational field of reinforcement learning have revolutionized the study of learning in the brain, famously providing new, precise theories of how dopamine affects learning in the basal ganglia. However, reinforcement learning algorithms are notorious for not scaling well to multidimensional environments, as is required for real-world learning. We hypothesized that the brain naturally reduces the dimensionality of real-world problems to only those dimensions that are relevant to predicting reward, and conducted an experiment to assess by what algorithms and with what neural mechanisms this "representation learning" process is realized in humans. Our results suggest that a bilateral attentional control network comprising the intraparietal sulcus, precuneus, and dorsolateral prefrontal cortex is involved in selecting what dimensions are relevant to the task at hand, effectively updating the task representation through trial and error. In this way, cortical attention mechanisms interact with learning in the basal ganglia to solve the "curse of dimensionality" in reinforcement learning. Copyright © 2015 the authors 0270-6474/15/358145-13$15.00/0.

Self-motion impairs multiple-object tracking.

PubMed

Thomas, Laura E; Seiffert, Adriane E

2010-10-01

Investigations of multiple-object tracking aim to further our understanding of how people perform common activities such as driving in traffic. However, tracking tasks in the laboratory have overlooked a crucial component of much real-world object tracking: self-motion. We investigated the hypothesis that keeping track of one's own movement impairs the ability to keep track of other moving objects. Participants attempted to track multiple targets while either moving around the tracking area or remaining in a fixed location. Participants' tracking performance was impaired when they moved to a new location during tracking, even when they were passively moved and when they did not see a shift in viewpoint. Self-motion impaired multiple-object tracking in both an immersive virtual environment and a real-world analog, but did not interfere with a difficult non-spatial tracking task. These results suggest that people use a common mechanism to track changes both to the location of moving objects around them and to keep track of their own location. Copyright 2010 Elsevier B.V. All rights reserved.

Combined node and link partitions method for finding overlapping communities in complex networks

PubMed Central

Jin, Di; Gabrys, Bogdan; Dang, Jianwu

2015-01-01

Community detection in complex networks is a fundamental data analysis task in various domains, and how to effectively find overlapping communities in real applications is still a challenge. In this work, we propose a new unified model and method for finding the best overlapping communities on the basis of the associated node and link partitions derived from the same framework. Specifically, we first describe a unified model that accommodates node and link communities (partitions) together, and then present a nonnegative matrix factorization method to learn the parameters of the model. Thereafter, we infer the overlapping communities based on the derived node and link communities, i.e., determine each overlapped community between the corresponding node and link community with a greedy optimization of a local community function conductance. Finally, we introduce a model selection method based on consensus clustering to determine the number of communities. We have evaluated our method on both synthetic and real-world networks with ground-truths, and compared it with seven state-of-the-art methods. The experimental results demonstrate the superior performance of our method over the competing ones in detecting overlapping communities for all analysed data sets. Improved performance is particularly pronounced in cases of more complicated networked community structures. PMID:25715829

Using a virtual world for robot planning

NASA Astrophysics Data System (ADS)

Benjamin, D. Paul; Monaco, John V.; Lin, Yixia; Funk, Christopher; Lyons, Damian

2012-06-01

We are building a robot cognitive architecture that constructs a real-time virtual copy of itself and its environment, including people, and uses the model to process perceptual information and to plan its movements. This paper describes the structure of this architecture. The software components of this architecture include PhysX for the virtual world, OpenCV and the Point Cloud Library for visual processing, and the Soar cognitive architecture that controls the perceptual processing and task planning. The RS (Robot Schemas) language is implemented in Soar, providing the ability to reason about concurrency and time. This Soar/RS component controls visual processing, deciding which objects and dynamics to render into PhysX, and the degree of detail required for the task. As the robot runs, its virtual model diverges from physical reality, and errors grow. The Match-Mediated Difference component monitors these errors by comparing the visual data with corresponding data from virtual cameras, and notifies Soar/RS of significant differences, e.g. a new object that appears, or an object that changes direction unexpectedly. Soar/RS can then run PhysX much faster than real-time and search among possible future world paths to plan the robot's actions. We report experimental results in indoor environments.

Meet Mai-Anh Ha | NREL

Science.gov Websites

find the best versions of the materials to guide experimentalists. "The world is complex," specifics," she says, "and then you can go from modeling into real-world applications." All to then choke me in my car," she says. Instead, she envisions a world filled with fuel cell cars

Quantifying uncertainty in high-resolution coupled hydrodynamic-ecosystem models

NASA Astrophysics Data System (ADS)

Allen, J. I.; Somerfield, P. J.; Gilbert, F. J.

2007-01-01

Marine ecosystem models are becoming increasingly complex and sophisticated, and are being used to estimate the effects of future changes in the earth system with a view to informing important policy decisions. Despite their potential importance, far too little attention has been, and is generally, paid to model errors and the extent to which model outputs actually relate to real-world processes. With the increasing complexity of the models themselves comes an increasing complexity among model results. If we are to develop useful modelling tools for the marine environment we need to be able to understand and quantify the uncertainties inherent in the simulations. Analysing errors within highly multivariate model outputs, and relating them to even more complex and multivariate observational data, are not trivial tasks. Here we describe the application of a series of techniques, including a 2-stage self-organising map (SOM), non-parametric multivariate analysis, and error statistics, to a complex spatio-temporal model run for the period 1988-1989 in the Southern North Sea, coinciding with the North Sea Project which collected a wealth of observational data. We use model output, large spatio-temporally resolved data sets and a combination of methodologies (SOM, MDS, uncertainty metrics) to simplify the problem and to provide tractable information on model performance. The use of a SOM as a clustering tool allows us to simplify the dimensions of the problem while the use of MDS on independent data grouped according to the SOM classification allows us to validate the SOM. The combination of classification and uncertainty metrics allows us to pinpoint the variables and associated processes which require attention in each region. We recommend the use of this combination of techniques for simplifying complex comparisons of model outputs with real data, and analysis of error distributions.

Involvement of Spearman's g in conceptualisation versus execution of complex tasks.

PubMed

Carroll, Ellen L; Bright, Peter

2016-10-01

Strong correlations between measures of fluid intelligence (or Spearman's g) and working memory are widely reported in the literature, but there is considerable controversy concerning the nature of underlying mechanisms driving this relationship. In the four experiments presented here we consider the role of response conflict and task complexity in the context of real-time task execution demands (Experiments 1-3) and also address recent evidence that g confers an advantage at the level of task conceptualisation rather than (or in addition to) task execution (Experiment 4). We observed increased sensitivity of measured fluid intelligence to task performance in the presence (vs. the absence) of response conflict, and this relationship remained when task complexity was reduced. Performance-g correlations were also observed in the absence of response conflict, but only in the context of high task complexity. Further, we present evidence that differences in conceptualisation or 'modelling' of task instructions prior to execution had an important mediating effect on observed correlations, but only when the task encompassed a strong element of response inhibition. Our results suggest that individual differences in ability reflect, in large part, variability in the efficiency with which the relational complexity of task constraints are held in mind. It follows that fluid intelligence may support successful task execution through the construction of effective action plans via optimal allocation of limited resources. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Complexity management theory: motivation for ideological rigidity and social conflict.

PubMed

Peterson, Jordan B; Flanders, Joseph L

2002-06-01

We are doomed to formulate conceptual structures that are much simpler than the complex phenomena they are attempting to account for. These simple conceptual structures shield us, pragmatically, from real-world complexity, but also fail, frequently, as some aspect of what we did not take into consideration makes itself manifest. The failure of our concepts dysregulates our emotions and generates anxiety, necessarily, as the unconstrained world is challenging and dangerous. Such dysregulation can turn us into rigid, totalitarian dogmatists, as we strive to maintain the structure of our no longer valid beliefs. Alternatively, we can face the underlying complexity of experience, voluntarily, gather new information, and recast and reconfigure the structures that underly our habitable worlds.

Real-Time Performance Feedback for the Manual Control of Spacecraft

NASA Astrophysics Data System (ADS)

Karasinski, John Austin

Real-time performance metrics were developed to quantify workload, situational awareness, and manual task performance for use as visual feedback to pilots of aerospace vehicles. Results from prior lunar lander experiments with variable levels of automation were replicated and extended to provide insights for the development of real-time metrics. Increased levels of automation resulted in increased flight performance, lower workload, and increased situational awareness. Automated Speech Recognition (ASR) was employed to detect verbal callouts as a limited measure of subjects' situational awareness. A one-dimensional manual tracking task and simple instructor-model visual feedback scheme was developed. This feedback was indicated to the operator by changing the color of a guidance element on the primary flight display, similar to how a flight instructor points out elements of a display to a student pilot. Experiments showed that for this low-complexity task, visual feedback did not change subject performance, but did increase the subjects' measured workload. Insights gained from these experiments were applied to a Simplified Aid for EVA Rescue (SAFER) inspection task. The effects of variations of an instructor-model performance-feedback strategy on human performance in a novel SAFER inspection task were investigated. Real-time feedback was found to have a statistically significant effect of improving subject performance and decreasing workload in this complicated four degree of freedom manual control task with two secondary tasks.

Air-Track: a real-world floating environment for active sensing in head-fixed mice

PubMed Central

Oraby, Hatem; Sachdev, Robert N. S.; Winter, York

2016-01-01

Natural behavior occurs in multiple sensory and motor modalities and in particular is dependent on sensory feedback that constantly adjusts behavior. To investigate the underlying neuronal correlates of natural behavior, it is useful to have access to state-of-the-art recording equipment (e.g., 2-photon imaging, patch recordings, etc.) that frequently requires head fixation. This limitation has been addressed with various approaches such as virtual reality/air ball or treadmill systems. However, achieving multimodal realistic behavior in these systems can be challenging. These systems are often also complex and expensive to implement. Here we present “Air-Track,” an easy-to-build head-fixed behavioral environment that requires only minimal computational processing. The Air-Track is a lightweight physical maze floating on an air table that has all the properties of the “real” world, including multiple sensory modalities tightly coupled to motor actions. To test this system, we trained mice in Go/No-Go and two-alternative forced choice tasks in a plus maze. Mice chose lanes and discriminated apertures or textures by moving the Air-Track back and forth and rotating it around themselves. Mice rapidly adapted to moving the track and used visual, auditory, and tactile cues to guide them in performing the tasks. A custom-controlled camera system monitored animal location and generated data that could be used to calculate reaction times in the visual and somatosensory discrimination tasks. We conclude that the Air-Track system is ideal for eliciting natural behavior in concert with virtually any system for monitoring or manipulating brain activity. PMID:27486102

Embedding of Authentic Assessment in Work-Integrated Learning Curriculum

ERIC Educational Resources Information Center

Bosco, Anna Maria; Ferns, Sonia

2014-01-01

Contemporary perspectives of higher education endorse a work integrated learning (WIL) approach to curriculum content, delivery and assessment. It is agreed that authenticity in learning relates to real-world experience, however, differentiating and strategically linking WIL provision and facilitation to assessment tasks and collation of authentic…

Applied use of cardiac and respiration measures: practical considerations and precautions.

PubMed

Wilson, G F

1992-11-01

Cardiac and respiratory measures can be successfully applied to "real world" environments and these measures have certain advantages over both performance and subjective measures that are typically used to monitor operator state and workload. However, because of large differences between laboratory and "real world" environments one must utilize caution in directly applying laboratory data and theories to the day-to-day world environment. While most workers are highly over-trained in their jobs, laboratory subjects are often under-trained in the cognitive tasks that are used to study cognitive activity. It is possible that a substantial portion of experimental effects reported in laboratory studies is due to learning effects. In addition, relatively small changes in cardiac and respiration measures are reported to experimental manipulations in the laboratory while a much larger range of changes are reported in "real world" environments. These differences highlight questions about laboratory/real world similarities and the need to develop a database of actual work environment data. A third area of concern is the relative lack of control over the experimental situation that is the case with most applied research. The possible confounding of changes due to cognitive and physical activity levels is a major concern and strategies for overcoming these problems are suggested. The potential for valuable contributions by cardiac and respiratory measures to applied research make overcoming these difficulties worthwhile.

The ecological and construct validity of a newly developed measure of executive function: the Virtual Library Task.

PubMed

Renison, Belinda; Ponsford, Jennie; Testa, Renee; Richardson, Barry; Brownfield, Kylie

2012-05-01

Virtual reality (VR) assessment paradigms have the potential to address the limited ecological validity of pen and paper measures of executive function (EF) and the pragmatic and reliability issues associated with functional measures. To investigate the ecological validity and construct validity of a newly developed VR measure of EF, the Virtual Library Task (VLT); a real life analogous task--the Real Library Task (RLT); and five neuropsychological measures of EF were administered to 30 patients with traumatic brain injury (TBI) and 30 healthy Controls. Significant others for each participant also completed the Dysexecutive Questionnaire (DEX), which is a behavioral rating scale of everyday EF. Performances on the VLT and the RLT were significantly positively correlated indicating that VR performance is similar to real world performance. The TBI group performed significantly worse than the Control group on the VLT and the Modified Six Elements Test (MSET) but the other four neuropsychological measures of EF failed to differentiate the groups. Both the MSET and the VLT significantly predicted everyday EF suggesting that they are both ecologically valid tools for the assessment of EF. The VLT has the advantage over the MSET of providing objective measurement of individual components of EF.

Efficient estimation of ideal-observer performance in classification tasks involving high-dimensional complex backgrounds

PubMed Central

Park, Subok; Clarkson, Eric

2010-01-01

The Bayesian ideal observer is optimal among all observers and sets an absolute upper bound for the performance of any observer in classification tasks [Van Trees, Detection, Estimation, and Modulation Theory, Part I (Academic, 1968).]. Therefore, the ideal observer should be used for objective image quality assessment whenever possible. However, computation of ideal-observer performance is difficult in practice because this observer requires the full description of unknown, statistical properties of high-dimensional, complex data arising in real life problems. Previously, Markov-chain Monte Carlo (MCMC) methods were developed by Kupinski et al. [J. Opt. Soc. Am. A 20, 430(2003) ] and by Park et al. [J. Opt. Soc. Am. A 24, B136 (2007) and IEEE Trans. Med. Imaging 28, 657 (2009) ] to estimate the performance of the ideal observer and the channelized ideal observer (CIO), respectively, in classification tasks involving non-Gaussian random backgrounds. However, both algorithms had the disadvantage of long computation times. We propose a fast MCMC for real-time estimation of the likelihood ratio for the CIO. Our simulation results show that our method has the potential to speed up ideal-observer performance in tasks involving complex data when efficient channels are used for the CIO. PMID:19884916

Real-World Evidence In Support Of Precision Medicine: Clinico-Genomic Cancer Data As A Case Study.

PubMed

Agarwala, Vineeta; Khozin, Sean; Singal, Gaurav; O'Connell, Claire; Kuk, Deborah; Li, Gerald; Gossai, Anala; Miller, Vincent; Abernethy, Amy P

2018-05-01

The majority of US adult cancer patients today are diagnosed and treated outside the context of any clinical trial (that is, in the real world). Although these patients are not part of a research study, their clinical data are still recorded. Indeed, data captured in electronic health records form an ever-growing, rich digital repository of longitudinal patient experiences, treatments, and outcomes. Likewise, genomic data from tumor molecular profiling are increasingly guiding oncology care. Linking real-world clinical and genomic data, as well as information from other co-occurring data sets, could create study populations that provide generalizable evidence for precision medicine interventions. However, the infrastructure required to link, ensure quality, and rapidly learn from such composite data is complex. We outline the challenges and describe a novel approach to building a real-world clinico-genomic database of patients with cancer. This work represents a case study in how data collected during routine patient care can inform precision medicine efforts for the population at large. We suggest that health policies can promote innovation by defining appropriate uses of real-world evidence, establishing data standards, and incentivizing data sharing.

Probabilistic Low-Rank Multitask Learning.

PubMed

Kong, Yu; Shao, Ming; Li, Kang; Fu, Yun

2018-03-01

In this paper, we consider the problem of learning multiple related tasks simultaneously with the goal of improving the generalization performance of individual tasks. The key challenge is to effectively exploit the shared information across multiple tasks as well as preserve the discriminative information for each individual task. To address this, we propose a novel probabilistic model for multitask learning (MTL) that can automatically balance between low-rank and sparsity constraints. The former assumes a low-rank structure of the underlying predictive hypothesis space to explicitly capture the relationship of different tasks and the latter learns the incoherent sparse patterns private to each task. We derive and perform inference via variational Bayesian methods. Experimental results on both regression and classification tasks on real-world applications demonstrate the effectiveness of the proposed method in dealing with the MTL problems.

The great chemical residue detection debate: dog versus machine

NASA Astrophysics Data System (ADS)

Tripp, Alan C.; Walker, James C.

2003-09-01

Many engineering groups desire to construct instrumentation to replace dog-handler teams in identifying and localizing chemical mixtures. This goal requires performance specifications for an "artificial dog-handler team". Progress toward generating such specifications from laboratory tests of dog-handler teams has been made recently at the Sensory Research Institute, and the method employed is amenable to the measurement of tasks representative of the decision-making that must go on when such teams solve problems in actual (and therefore informationally messy) situations. As progressively more quantitative data are obtained on progressively more complex odor tasks, the boundary conditions of dog-handler performance will be understood in great detail. From experiments leading to this knowledge, one ca develop, as we do in this paper, a taxonomy of test conditions that contain various subsets of the variables encountered in "real world settings". These tests provide the basis for the rigorous testing that will provide an improved basis for deciding when biological sensing approaches (e.g. dog-handler teams) are best and when "artificial noses" are most valuable.

Optimal Modality Selection for Cooperative Human-Robot Task Completion.

PubMed

Jacob, Mithun George; Wachs, Juan P

2016-12-01

Human-robot cooperation in complex environments must be fast, accurate, and resilient. This requires efficient communication channels where robots need to assimilate information using a plethora of verbal and nonverbal modalities such as hand gestures, speech, and gaze. However, even though hybrid human-robot communication frameworks and multimodal communication have been studied, a systematic methodology for designing multimodal interfaces does not exist. This paper addresses the gap by proposing a novel methodology to generate multimodal lexicons which maximizes multiple performance metrics over a wide range of communication modalities (i.e., lexicons). The metrics are obtained through a mixture of simulation and real-world experiments. The methodology is tested in a surgical setting where a robot cooperates with a surgeon to complete a mock abdominal incision and closure task by delivering surgical instruments. Experimental results show that predicted optimal lexicons significantly outperform predicted suboptimal lexicons (p <; 0.05) in all metrics validating the predictability of the methodology. The methodology is validated in two scenarios (with and without modeling the risk of a human-robot collision) and the differences in the lexicons are analyzed.

Eating behavior: lessons from the real world of humans.

PubMed

de Castro, J M

2000-10-01

Food intake by normal humans has been investigated both in the laboratory and under free-living conditions in the natural environment. For measurement of real-world intake, the diet-diary technique is imperfect and tends to underestimate actual intakes but it appears to be sensitive, can detect subtle influences on eating behavior, and produces reliable and valid measures. Research studies in the real world show the multivariate richness of the natural environment, which allows investigation of the complexities of intake regulation, and even causation can be investigated. Real-world research can overcome some of the weaknesses of laboratory studies, where constraints on eating are often removed or missing, facilitatory influences on eating are often controlled or eliminated, the importance of variables can be overestimated, and important influences can be missed because of the short durations of the studies. Real-world studies have shown a wide array of physiologic, psychological, and social variables that can have potent and immediate effects on intake. Compensatory mechanisms, including some that operate with a 2- to 3-d delay, adjust for prior excesses. Heredity affects all aspect of food-intake regulation, from the determination of body size to the subtleties of the individual preferences and social proclivities and the extent to which environmental factors affect the individual. Hence, real-world research teaches valuable lessons, and much more is needed to complement laboratory studies.

The Role of Temporal Trends in Growing Networks

PubMed Central

Ruppin, Eytan; Shavitt, Yuval

2016-01-01

The rich get richer principle, manifested by the Preferential attachment (PA) mechanism, is widely considered one of the major factors in the growth of real-world networks. PA stipulates that popular nodes are bound to be more attractive than less popular nodes; for example, highly cited papers are more likely to garner further citations. However, it overlooks the transient nature of popularity, which is often governed by trends. Here, we show that in a wide range of real-world networks the recent popularity of a node, i.e., the extent by which it accumulated links recently, significantly influences its attractiveness and ability to accumulate further links. We proceed to model this observation with a natural extension to PA, named Trending Preferential Attachment (TPA), in which edges become less influential as they age. TPA quantitatively parametrizes a fundamental network property, namely the network’s tendency to trends. Through TPA, we find that real-world networks tend to be moderately to highly trendy. Networks are characterized by different susceptibilities to trends, which determine their structure to a large extent. Trendy networks display complex structural traits, such as modular community structure and degree-assortativity, occurring regularly in real-world networks. In summary, this work addresses an inherent trait of complex networks, which greatly affects their growth and structure, and develops a unified model to address its interaction with preferential attachment. PMID:27486847

Thickening the Fog: The Truncation of Air Intelligence Since World War II

DTIC Science & Technology

2010-06-01

the US Government with global situational awareness, real - time engagement support, SIGINT and near real time IMINT, agile systems , and access to...The scarcity of reliable and detailed intelligence on the USSR precludes the determination at this time of specific target systems for air... time consuming task. This system is in no way haphazard, and in no way could the term ‘indiscriminate’ be applied to it.”38 One of the largest

Collaborative business process support in eHealth: integrating IHE profiles through ebXML business process specification language.

PubMed

Dogac, Asuman; Kabak, Yildiray; Namli, Tuncay; Okcan, Alper

2008-11-01

Integrating healthcare enterprise (IHE) specifies integration profiles describing selected real world use cases to facilitate the interoperability of healthcare information resources. While realizing a complex real-world scenario, IHE profiles are combined by grouping the related IHE actors. Grouping IHE actors implies that the associated business processes (IHE profiles) that the actors are involved must be combined, that is, the choreography of the resulting collaborative business process must be determined by deciding on the execution sequence of transactions coming from different profiles. There are many IHE profiles and each user or vendor may support a different set of IHE profiles that fits to its business need. However, determining the precedence of all the involved transactions manually for each possible combination of the profiles is a very tedious task. In this paper, we describe how to obtain the overall business process automatically when IHE actors are grouped. For this purpose, we represent the IHE profiles through a standard, machine-processable language, namely, Organization for the Advancement of Structured Information Standards (OASIS) ebusiness eXtensible Markup Language (ebXML) Business Process Specification (ebBP) Language. We define the precedence rules among the transactions of the IHE profiles, again, in a machine-processable way. Then, through a graphical tool, we allow users to select the actors to be grouped and automatically produce the overall business process in a machine-processable format.

Implementation of Discovery Projects in Statistics

ERIC Educational Resources Information Center

Bailey, Brad; Spence, Dianna J.; Sinn, Robb

2013-01-01

Researchers and statistics educators consistently suggest that students will learn statistics more effectively by conducting projects through which they actively engage in a broad spectrum of tasks integral to statistical inquiry, in the authentic context of a real-world application. In keeping with these findings, we share an implementation of…

Brain Activity on Navigation in Virtual Environments.

ERIC Educational Resources Information Center

Mikropoulos, Tassos A.

2001-01-01

Assessed the cognitive processing that takes place in virtual environments by measuring electrical brain activity using Fast Fourier Transform analysis. University students performed the same task in a real and a virtual environment, and eye movement measurements showed that all subjects were more attentive when navigating in the virtual world.…

Probing for Reasons: Presentations, Questions, Phases

ERIC Educational Resources Information Center

Morris, Kellyn Farlow; Speiser, Bob

2010-01-01

This paper reports on a research study based on data from experimental teaching. Undergraduate dance majors were invited, through real-world problem tasks that raised central conceptual issues, to invent major ideas of calculus. This study focuses on work and thinking by these students, as they sought to build key ideas, representations and…

Dancing with STEAM: Creative Movement Generates Electricity for Young Learners

ERIC Educational Resources Information Center

Simpson Steele, Jamie; Fulton, Lori; Fanning, Lisa

2016-01-01

The integration of science, technology, engineering, arts, and mathematics (STEAM) serves to develop creative thinking and twenty-first-century skills in the classroom (Maeda 2012). Learning through STEAM promotes novelty, innovation, ingenuity, and task-specific purposefulness to solve real-world problems--all aspects that define creativity. Lisa…

Camera calibration correction in shape from inconsistent silhouette

USDA-ARS?s Scientific Manuscript database

The use of shape from silhouette for reconstruction tasks is plagued by two types of real-world errors: camera calibration error and silhouette segmentation error. When either error is present, we call the problem the Shape from Inconsistent Silhouette (SfIS) problem. In this paper, we show how sm...

Self-Motion Impairs Multiple-Object Tracking

ERIC Educational Resources Information Center

Thomas, Laura E.; Seiffert, Adriane E.

2010-01-01

Investigations of multiple-object tracking aim to further our understanding of how people perform common activities such as driving in traffic. However, tracking tasks in the laboratory have overlooked a crucial component of much real-world object tracking: self-motion. We investigated the hypothesis that keeping track of one's own movement…

Simulations, Learning and Real World Capabilities

ERIC Educational Resources Information Center

Wood, Robert E.; Beckmann, Jens F.; Birney, Damian P.

2009-01-01

Purpose: The purpose of this paper is to consider how simulations are increasingly used in training programs for the development of skills such as leadership. However, the requirements of leadership development go beyond the development of task specific procedural knowledge or expertise that simulations have typically been used to develop.…

Real change in the real world: an achievable goal.

PubMed

Friedman, Robert M

2010-03-01

This commentary builds on the papers presented at the Vanderbilt Conference by emphasizing the importance of better understanding the process of change-making if real change in the real world is to be achieved. The commentary reviews several frameworks and research findings related to achieving large-scale sustainable change that benefits children and families. It calls for the application of systems thinking as a complement to the more micro-level research that was presented at the Vanderbilt conference. Such an approach would have implications for framing of the issue, for the strategies that are taken to try to achieve change, and for research/evaluation methods for studying complex, dynamic, nonlinear systems.

Building an intelligent tutoring system for procedural domains

NASA Technical Reports Server (NTRS)

Warinner, Andrew; Barbee, Diann; Brandt, Larry; Chen, Tom; Maguire, John

1990-01-01

Jobs that require complex skills that are too expensive or dangerous to develop often use simulators in training. The strength of a simulator is its ability to mimic the 'real world', allowing students to explore and experiment. A good simulation helps the student develop a 'mental model' of the real world. The closer the simulation is to 'real life', the less difficulties there are transferring skills and mental models developed on the simulator to the real job. As graphics workstations increase in power and become more affordable they become attractive candidates for developing computer-based simulations for use in training. Computer based simulations can make training more interesting and accessible to the student.

Parallel Online Temporal Difference Learning for Motor Control.

PubMed

Caarls, Wouter; Schuitema, Erik

2016-07-01

Temporal difference (TD) learning, a key concept in reinforcement learning, is a popular method for solving simulated control problems. However, in real systems, this method is often avoided in favor of policy search methods because of its long learning time. But policy search suffers from its own drawbacks, such as the necessity of informed policy parameterization and initialization. In this paper, we show that TD learning can work effectively in real robotic systems as well, using parallel model learning and planning. Using locally weighted linear regression and trajectory sampled planning with 14 concurrent threads, we can achieve a speedup of almost two orders of magnitude over regular TD control on simulated control benchmarks. For a real-world pendulum swing-up task and a two-link manipulator movement task, we report a speedup of 20× to 60× , with a real-time learning speed of less than half a minute. The results are competitive with state-of-the-art policy search.

Virtual fixtures as tools to enhance operator performance in telepresence environments

NASA Astrophysics Data System (ADS)

Rosenberg, Louis B.

1993-12-01

This paper introduces the notion of virtual fixtures for use in telepresence systems and presents an empirical study which demonstrates that such virtual fixtures can greatly enhance operator performance within remote environments. Just as tools and fixtures in the real world can enhance human performance by guiding manual operations, providing localizing references, and reducing the mental processing required to perform a task, virtual fixtures are computer generated percepts overlaid on top of the reflection of a remote workspace which can provide similar benefits. Like a ruler guiding a pencil in a real manipulation task, a virtual fixture overlaid on top of a remote workspace can act to reduce the mental processing required to perform a task, limit the workload of certain sensory modalities, and most of all allow precision and performance to exceed natural human abilities. Because such perceptual overlays are virtual constructions they can be diverse in modality, abstract in form, and custom tailored to individual task or user needs. This study investigates the potential of virtual fixtures by implementing simple combinations of haptic and auditory sensations as perceptual overlays during a standardized telemanipulation task.

Design-based science and the transfer of science knowledge and real-world problem-solving skills

NASA Astrophysics Data System (ADS)

Fortus, David Leon

Design-Based Science (DBS) helps students develop new scientific knowledge and problem-solving skills in the context of designing artifacts. This pedagogy was developed as a response to the potential problem of transfer of knowledge from academic settings to extra classroom environments. This dissertation describes DBS in detail and attempts to answer three questions: (1) Do DBS curricula support students' efforts to transfer newly constructed science knowledge and 'designerly' skills (Baynes, 1994) to the solution of new real-world design problems in an extra-classroom setting? (2) Do DBS curricula support students' efforts to construct new scientific knowledge? (3) Do DBS curricula support students' efforts to develop 'designerly' problem-solving skills? Ninety-two students attending a public high school serving a working class community participated in the consecutive enactments of three different DBS units over one school year. The analysis of pre- and posttests and of artifacts created by the students demonstrated that substantial knowledge was constructed during each of the enactments, with the tests leading to effect sizes of 2.1 on the first unit, 1.9 on the second, and 2.7 on the third. After each enactment the students solved a new design problem as a transfer task. The transfer tasks were unsequestered, unsupported by the teacher, lasted three days, were done in the school's library, required new learning, and were solved in groups of four. In order to generate an individual measure of transfer, the students responded to an individual post-transfer written test after each transfer task was completed, that assessed their understanding and recollection of the solution their group submitted. For all three units there was a stronger correlation between the individual transfer scores and posttests scores than with pretest scores, indicating that the knowledge and skills that were constructed during the enactments supported the solution of the transfer tasks. The correlations with the posttests increased from one enactment to the next, demonstrating that the students' transfer performance improved as they gained more experience in DBS classrooms. Potential threats to the study's internal validity that were identified and discussed were improved teacher proficiency, the nature of the transfer tasks, the difficulty of the science content covered by the units, the similarity between the units and the transfer tasks, and the similarity between the transfer tasks. This dissertation demonstrates that: (a) appropriate learning environments can foster transfer, (b) transfer performance can improve over time, and (c) that it may be necessary to rethink and redefine the procedures for identifying and assessing real-world transfer.

Imagining Counterfactual Worlds in Autism Spectrum Disorder.

PubMed

Black, Jo; Williams, David; Ferguson, Heather J

2018-02-01

Two experiments are presented that explore online counterfactual processing in autism spectrum disorder (ASD) using eye-tracking. Participants' eye movements were tracked while they read factual and counterfactual sentences in an anomaly detection task. In Experiment 1, the sentences depicted everyday counterfactual situations (e.g., If Joanne had remembered her umbrella, her hair would have been dry/wet when she arrived home). Sentences in Experiment 2 depicted counterfactual versions of real world events (e.g., If the Titanic had not hit an iceberg, it would have survived/sunk along with all the passengers). Results from both experiments suggest that counterfactual understanding is undiminished in adults with ASD. In fact, participants with ASD were faster than Typically Developing (TD) participants to detect anomalies within realistic, discourse-based counterfactuals (Experiment 1). Detection was comparable for TD and ASD groups when understanding could be grounded in knowledge about reality (Experiment 2), though the 2 groups used subtly different strategies for responding to and recovering from counterfactual inconsistent words. These data argue against general difficulties in global coherence and complex integration in ASD. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Evolutionary Developmental Robotics: Improving Morphology and Control of Physical Robots.

PubMed

Vujovic, Vuk; Rosendo, Andre; Brodbeck, Luzius; Iida, Fumiya

2017-01-01

Evolutionary algorithms have previously been applied to the design of morphology and control of robots. The design space for such tasks can be very complex, which can prevent evolution from efficiently discovering fit solutions. In this article we introduce an evolutionary-developmental (evo-devo) experiment with real-world robots. It allows robots to grow their leg size to simulate ontogenetic morphological changes, and this is the first time that such an experiment has been performed in the physical world. To test diverse robot morphologies, robot legs of variable shapes were generated during the evolutionary process and autonomously built using additive fabrication. We present two cases with evo-devo experiments and one with evolution, and we hypothesize that the addition of a developmental stage can be used within robotics to improve performance. Moreover, our results show that a nonlinear system-environment interaction exists, which explains the nontrivial locomotion patterns observed. In the future, robots will be present in our daily lives, and this work introduces for the first time physical robots that evolve and grow while interacting with the environment.

Neural correlates of naturalistic social cognition: brain-behavior relationships in healthy adults

PubMed Central

Rademacher, L.M.; Winkler, L.; Schultz, R.T.; Gründer, G.; Lammertz, S.E.

2016-01-01

Being able to infer the thoughts, feelings and intentions of those around us is indispensable in order to function in a social world. Despite growing interest in social cognition and its neural underpinnings, the factors that contribute to successful mental state attribution remain unclear. Current knowledge is limited because the most widely used tasks suffer from two main constraints: (i) They fail to capture individual variability due to ceiling effects and (ii) they use highly simplistic, often artificial stimuli inapt to mirror real-world socio-cognitive demands. In the present study, we address these problems by employing complex depictions of naturalistic social interactions that vary in both valence (positive vs negative) and ambiguity (high vs low). Thirty-eight healthy participants (20 female) made mental state judgments while brain responses were obtained using functional magnetic resonance imaging (fMRI). Accuracy varied based on valence and ambiguity conditions and women were more accurate than men with highly ambiguous social stimuli. Activity of the orbitofrontal cortex predicted performance in the high ambiguity condition. The results shed light on subtle differences in mentalizing abilities and associated neural activity. PMID:27496338

Neurophysiologic monitoring of mental workload and fatigue during operation of a flight simulator

NASA Astrophysics Data System (ADS)

Smith, Michael E.; Gevins, Alan

2005-05-01

In one experiment, EEG recordings were made during a daytime session while 16 well-rested participants performed versions of a PC flight simulator task that were either low, moderate, or high in difficulty. In another experiment, the same subjects repeatedly performed high difficulty versions of the same task during an all night session with total sleep deprivation. Multivariate EEG metrics of cortical activation were derived for frontal brain regions essential for working memory and executive control processes that are presumably important for maintaining situational awareness, central brain regions essential for sensorimotor control, and posterior parietal and occipital regions essential for visuoperceptual processing. During the daytime session each of these regional measures displayed greater activation during the high difficulty task than during the low difficulty task, and degree of cortical activation was positively correlated with subjective workload ratings in these well-rested subjects. During the overnight session, cortical activation declined with time-on-task, and the degree of this decline over frontal regions was negatively correlated with subjective workload ratings. Since participants were already highly skilled in the task, such changes likely reflect fatigue-related diminishment of frontal executive capability rather than practice effects. These findings suggest that the success of efforts to gauge mental workload via proxy cortical activation measures in the context of adaptive automation systems will likely depend on use of user models that take both task demands and the operator"s state of alertness into account. Further methodological development of the measurement approach outlined here would be required to achieve a practical, effective objective means for monitoring transient changes in cognitive brain function during performance of complex real-world tasks.

Effects of Healthy Aging and Mild Cognitive Impairment on a Real-Life Decision-Making Task.

PubMed

Pertl, Marie-Theres; Benke, Thomas; Zamarian, Laura; Delazer, Margarete

2017-01-01

In this study, we investigated the effects of age and of mild cognitive impairment (MCI) on decision making under risk by adopting a task representing real-life health-related situations and involving complex numerical information. Moreover, we assessed the relationship of real-life decision making to other cognitive functions such as number processing, executive functions, language, memory, and attention. For this reason, we compared the performance of 19 healthy, relatively younger adults with that of 18 healthy older adults and the performance of the 18 healthy older adults with that of 17 patients with MCI. Results indicated difficulties in real-life decision making for the healthy older adults compared with the healthy, relatively younger adults. Difficulties of patients with MCI relative to the healthy older adults arose in particular in difficult items requiring processing of frequencies and fractions. Significant effects of age and of MCI in processing frequencies were also evident in a ratio number comparison task. Decision-making performance of healthy participants and of the patient group correlated significantly with number processing. There was a further significant correlation with executive functions for the healthy participants and with reading comprehension for the patients. Our results suggest that healthy older individuals and patients with MCI make less advantageous decisions when the information is complex and high demands are put on executive functions and numerical abilities. Moreover, we show that executive functions and numerical abilities are not only essential in laboratory gambling tasks but also in more realistic and ecological decision situations within the health context.

People detection in crowded scenes using active contour models

NASA Astrophysics Data System (ADS)

Sidla, Oliver

2009-01-01

The detection of pedestrians in real-world scenes is a daunting task, especially in crowded situations. Our experience over the last years has shown that active shape models (ASM) can contribute significantly to a robust pedestrian detection system. The paper starts with an overview of shape model approaches, it then explains our approach which builds on top of Eigenshape models which have been trained using real-world data. These models are placed over candidate regions and matched to image gradients using a scoring function which integrates i) point distribution, ii) local gradient orientations iii) local image gradient strengths. A matching and shape model update process is iteratively applied in order to fit the flexible models to the local image content. The weights of the scoring function have a significant impact on the ASM performance. We analyze different settings of scoring weights for gradient magnitude, relative orientation differences, distance between model and gradient in an experiment which uses real-world data. Although for only one pedestrian model in an image computation time is low, the number of necessary processing cycles which is needed to track many people in crowded scenes can become the bottleneck in a real-time application. We describe the measures which have been taken in order to improve the speed of the ASM implementation and make it real-time capable.

Walkable Worlds give a Rich Self-Similar Structure to the Real Line

NASA Astrophysics Data System (ADS)

Rosinger, Elemér E.

2010-05-01

It is a rather universal tacit and unquestioned belief—and even more so among physicists—that there is one and only one real line, namely, given by the coodinatisation of Descartes through the usual field R of real numbers. Such a dramatically limiting and thus harmful belief comes, unknown to equally many, from the similarly tacit acceptance of the ancient Archimedean Axiom in Euclid's Geometry. The consequence of that belief is a similar belief in the uniqueness of the coordinatization of the plane by the usual field C of complex numbers, and therefore, of the various spaces, manifolds, etc., be they finite or infinite dimensional, constructed upon the real or complex numbers, including the Hilbert spaces used in Quantum Mechanics. A near total lack of awareness follows therefore about the rich self-similar structure of other possible coordinatisations of the real line, possibilities given by various linearly ordered scalar fields obtained through the ultrapower construction. Such fields contain as a rather small subset the usual field R of real numbers. The concept of walkable world, which has highly intuitive and pragmatic algebraic and geometric meaning, illustrates the mentioned rich self-similar structure.

Electrophysiology-based detection of emergency braking intention in real-world driving.

PubMed

Haufe, Stefan; Kim, Jeong-Woo; Kim, Il-Hwa; Sonnleitner, Andreas; Schrauf, Michael; Curio, Gabriel; Blankertz, Benjamin

2014-10-01

The fact that all human action is preceded by brain processes partially observable through neuroimaging devices such as electroencephalography (EEG) is currently being explored in a number of applications. A recent study by Haufe et al (2011 J. Neural Eng. 8 056001) demonstrates the possibility of performing fast detection of forced emergency brakings during driving based on EEG and electromyography, and discusses the use of such neurotechnology for braking assistance systems. Since the study was conducted in a driving simulator, its significance regarding real-world applicability needs to be assessed. Here, we replicate that experimental paradigm in a real car on a non-public test track. Our results resemble those of the simulator study, both qualitatively (in terms of the neurophysiological phenomena observed and utilized) and quantitatively (in terms of the predictive improvement achievable using electrophysiology in addition to behavioral measures). Moreover, our findings are robust with respect to a temporary secondary auditory task mimicking verbal input from a fellow passenger. Our study serves as a real-world verification of the feasibility of electrophysiology-based detection of emergency braking intention as proposed in Haufe et al (2011 J. Neural Eng. 8 056001).

Electrophysiology-based detection of emergency braking intention in real-world driving

NASA Astrophysics Data System (ADS)

Haufe, Stefan; Kim, Jeong-Woo; Kim, Il-Hwa; Sonnleitner, Andreas; Schrauf, Michael; Curio, Gabriel; Blankertz, Benjamin

2014-10-01

Objective. The fact that all human action is preceded by brain processes partially observable through neuroimaging devices such as electroencephalography (EEG) is currently being explored in a number of applications. A recent study by Haufe et al (2011 J. Neural Eng. 8 056001) demonstrates the possibility of performing fast detection of forced emergency brakings during driving based on EEG and electromyography, and discusses the use of such neurotechnology for braking assistance systems. Since the study was conducted in a driving simulator, its significance regarding real-world applicability needs to be assessed. Approach. Here, we replicate that experimental paradigm in a real car on a non-public test track. Main results. Our results resemble those of the simulator study, both qualitatively (in terms of the neurophysiological phenomena observed and utilized) and quantitatively (in terms of the predictive improvement achievable using electrophysiology in addition to behavioral measures). Moreover, our findings are robust with respect to a temporary secondary auditory task mimicking verbal input from a fellow passenger. Significance. Our study serves as a real-world verification of the feasibility of electrophysiology-based detection of emergency braking intention as proposed in Haufe et al (2011 J. Neural Eng. 8 056001).

Student Use of Physics to Make Sense of Incomplete but Functional VPython Programs in a Lab Setting

NASA Astrophysics Data System (ADS)

Weatherford, Shawn A.

2011-12-01

Computational activities in Matter & Interactions, an introductory calculus-based physics course, have the instructional goal of providing students with the experience of applying the same set of a small number of fundamental principles to model a wide range of physical systems. However there are significant instructional challenges for students to build computer programs under limited time constraints, especially for students who are unfamiliar with programming languages and concepts. Prior attempts at designing effective computational activities were successful at having students ultimately build working VPython programs under the tutelage of experienced teaching assistants in a studio lab setting. A pilot study revealed that students who completed these computational activities had significant difficultly repeating the exact same tasks and further, had difficulty predicting the animation that would be produced by the example program after interpreting the program code. This study explores the interpretation and prediction tasks as part of an instructional sequence where students are asked to read and comprehend a functional, but incomplete program. Rather than asking students to begin their computational tasks with modifying program code, we explicitly ask students to interpret an existing program that is missing key lines of code. The missing lines of code correspond to the algebraic form of fundamental physics principles or the calculation of forces which would exist between analogous physical objects in the natural world. Students are then asked to draw a prediction of what they would see in the simulation produced by the VPython program and ultimately run the program to evaluate the students' prediction. This study specifically looks at how the participants use physics while interpreting the program code and creating a whiteboard prediction. This study also examines how students evaluate their understanding of the program and modification goals at the beginning of the modification task. While working in groups over the course of a semester, study participants were recorded while they completed three activities using these incomplete programs. Analysis of the video data showed that study participants had little difficulty interpreting physics quantities, generating a prediction, or determining how to modify the incomplete program. Participants did not base their prediction solely from the information from the incomplete program. When participants tried to predict the motion of the objects in the simulation, many turned to their knowledge of how the system would evolve if it represented an analogous real-world physical system. For example, participants attributed the real-world behavior of springs to helix objects even though the program did not include calculations for the spring to exert a force when stretched. Participants rarely interpreted lines of code in the computational loop during the first computational activity, but this changed during latter computational activities with most participants using their physics knowledge to interpret the computational loop. Computational activities in the Matter & Interactions curriculum were revised in light of these findings to include an instructional sequence of tasks to build a comprehension of the example program. The modified activities also ask students to create an additional whiteboard prediction for the time-evolution of the real-world phenomena which the example program will eventually model. This thesis shows how comprehension tasks identified by Palinscar and Brown (1984) as effective in improving reading comprehension are also effective in helping students apply their physics knowledge to interpret a computer program which attempts to model a real-world phenomena and identify errors in their understanding of the use, or omission, of fundamental physics principles in a computational model.

Connectivity patterns in cognitive control networks predict naturalistic multitasking ability.

PubMed

Wen, Tanya; Liu, De-Cyuan; Hsieh, Shulan

2018-06-01

Multitasking is a fundamental aspect of everyday life activities. To achieve a complex, multi-component goal, the tasks must be subdivided into sub-tasks and component steps, a critical function of prefrontal networks. The prefrontal cortex is considered to be organized in a cascade of executive processes from the sensorimotor to anterior prefrontal cortex, which includes execution of specific goal-directed action, to encoding and maintaining task rules, and finally monitoring distal goals. In the current study, we used a virtual multitasking paradigm to tap into real-world performance and relate it to each individual's resting-state functional connectivity in fMRI. While did not find any correlation between global connectivity of any of the major networks with multitasking ability, global connectivity of the lateral prefrontal cortex (LPFC) was predictive of multitasking ability. Further analysis showed that multivariate connectivity patterns within the sensorimotor network (SMN), and between-network connectivity of the frontoparietal network (FPN) and dorsal attention network (DAN), predicted individual multitasking ability and could be generalized to novel individuals. Together, these results support previous research that prefrontal networks underlie multitasking abilities and show that connectivity patterns in the cascade of prefrontal networks may explain individual differences in performance. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Right-side-stretched multifractal spectra indicate small-worldness in networks

NASA Astrophysics Data System (ADS)

Oświȩcimka, Paweł; Livi, Lorenzo; Drożdż, Stanisław

2018-04-01

Complex network formalism allows to explain the behavior of systems composed by interacting units. Several prototypical network models have been proposed thus far. The small-world model has been introduced to mimic two important features observed in real-world systems: i) local clustering and ii) the possibility to move across a network by means of long-range links that significantly reduce the characteristic path length. A natural question would be whether there exist several ;types; of small-world architectures, giving rise to a continuum of models with properties (partially) shared with other models belonging to different network families. Here, we take advantage of the interplay between network theory and time series analysis and propose to investigate small-world signatures in complex networks by analyzing multifractal characteristics of time series generated from such networks. In particular, we suggest that the degree of right-sided asymmetry of multifractal spectra is linked with the degree of small-worldness present in networks. This claim is supported by numerical simulations performed on several parametric models, including prototypical small-world networks, scale-free, fractal and also real-world networks describing protein molecules. Our results also indicate that right-sided asymmetry emerges with the presence of the following topological properties: low edge density, low average shortest path, and high clustering coefficient.

Virtual/real transfer of spatial knowledge: benefit from visual fidelity provided in a virtual environment and impact of active navigation.

PubMed

Wallet, Grégory; Sauzéon, Hélène; Pala, Prashant Arvind; Larrue, Florian; Zheng, Xia; N'Kaoua, Bernard

2011-01-01

The purpose of this study was to evaluate the effect the visual fidelity of a virtual environment (VE) (undetailed vs. detailed) has on the transfer of spatial knowledge based on the navigation mode (passive vs. active) for three different spatial recall tasks (wayfinding, sketch mapping, and picture sorting). Sixty-four subjects (32 men and 32 women) participated in the experiment. Spatial learning was evaluated by these three tasks in the context of the Bordeaux district. In the wayfinding task, the results indicated that the detailed VE helped subjects to transfer their spatial knowledge from the VE to the real world, irrespective of the navigation mode. In the sketch-mapping task, the detailed VE increased performances compared to the undetailed VE condition, and allowed subjects to benefit from the active navigation. In the sorting task, performances were better in the detailed VE; however, in the undetailed version of the VE, active learning either did not help the subjects or it even deteriorated their performances. These results are discussed in terms of appropriate perceptive-motor and/or spatial representations for each spatial recall task.

Control of complex physically simulated robot groups

NASA Astrophysics Data System (ADS)

Brogan, David C.

2001-10-01

Actuated systems such as robots take many forms and sizes but each requires solving the difficult task of utilizing available control inputs to accomplish desired system performance. Coordinated groups of robots provide the opportunity to accomplish more complex tasks, to adapt to changing environmental conditions, and to survive individual failures. Similarly, groups of simulated robots, represented as graphical characters, can test the design of experimental scenarios and provide autonomous interactive counterparts for video games. The complexity of writing control algorithms for these groups currently hinders their use. A combination of biologically inspired heuristics, search strategies, and optimization techniques serve to reduce the complexity of controlling these real and simulated characters and to provide computationally feasible solutions.

Lateral occipitotemporal cortex (LOTC) activity is greatest while viewing dance compared to visualization and movement: learning and expertise effects.

PubMed

Di Nota, Paula M; Levkov, Gabriella; Bar, Rachel; DeSouza, Joseph F X

2016-07-01

The lateral occipitotemporal cortex (LOTC) is comprised of subregions selectively activated by images of human bodies (extrastriate body area, EBA), objects (lateral occipital complex, LO), and motion (MT+). However, their role in motor imagery and movement processing is unclear, as are the influences of learning and expertise on its recruitment. The purpose of our study was to examine putative changes in LOTC activation during action processing following motor learning of novel choreography in professional ballet dancers. Subjects were scanned with functional magnetic resonance imaging up to four times over 34 weeks and performed four tasks: viewing and visualizing a newly learned ballet dance, visualizing a dance that was not being learned, and movement of the foot. EBA, LO, and MT+ were activated most while viewing dance compared to visualization and movement. Significant increases in activation were observed over time in left LO only during visualization of the unlearned dance, and all subregions were activated bilaterally during the viewing task after 34 weeks of performance, suggesting learning-induced plasticity. Finally, we provide novel evidence for modulation of EBA with dance experience during the motor task, with significant activation elicited in a comparison group of novice dancers only. These results provide a composite of LOTC activation during action processing of newly learned ballet choreography and movement of the foot. The role of these areas is confirmed as primarily subserving observation of complex sequences of whole-body movement, with new evidence for modification by experience and over the course of real world ballet learning.

Evaluation of the nephrotoxicity of complex mixtures containing organics and metals: advantages and disadvantages of the use of real-world complex mixtures.

PubMed

Simmons, J E; Yang, R S; Berman, E

1995-02-01

As part of a multidisciplinary health effects study, the nephrotoxicity of complex industrial waste mixtures was assessed. Adult, male Fischer 344 rats were gavaged with samples of complex industrial waste and nephrotoxicity evaluated 24 hr later. Of the 10 tested samples, 4 produced increased absolute or relative kidney weight, or both, coupled with a statistically significant alteration in at least one of the measured serum parameters (urea nitrogen (BUN), creatinine (CREAT), and BUN/CREAT ratio). Although the waste samples had been analyzed for a number of organic chemicals and 7 of the 10 samples were analyzed also for 12 elemental metals and metalloids, their nephrotoxicity was not readily predicted from the partial chemical characterization data. Because the chemical form or speciation of the metals was unknown, it was not possible to estimate their contribution to the observed biological response. Various experimental approaches, including use of real-world complex mixtures, chemically defined synthetic mixtures, and simple mixtures, will be necessary to adequately determine the potential human health risk from exposure to complex chemical mixtures.

Effect of short-term exposure to stereoscopic three-dimensional flight displays on real-world depth perception

NASA Technical Reports Server (NTRS)

Busquets, Anthony M.; Parrish, Russell V.; Williams, Steven P.

1991-01-01

High-fidelity color pictorial displays that incorporate depth cues in the display elements are currently available. Depth cuing applied to advanced head-down flight display concepts potentially enhances the pilot's situational awareness and improves task performance. Depth cues provided by stereopsis exhibit constraints that must be fully understood so depth cuing enhancements can be adequately realized and exploited. A fundamental issue (the goal of this investigation) is whether the use of head-down stereoscopic displays in flight applications degrade the real-world depth perception of pilots using such displays. Stereoacuity tests are used in this study as the measure of interest. Eight pilots flew repeated simulated landing approaches using both nonstereo and stereo 3-D head-down pathway-in-the-sky displays. At this decision height of each approach (where the pilot changes to an out-the-window view to obtain real-world visual references) the pilots changed to a stereoacuity test that used real objects. Statistical analysis of stereoacuity measures (data for a control condition of no exposure to any electronic flight display compared with data for changes from nonstereo and from stereo displays) reveals no significant differences for any of the conditions. Therefore, changing from short-term exposure to a head-down stereo display has no more effect on real-world relative depth perception than does changing from a nonstereo display. However, depth perception effects based on sized and distance judgements and on long-term exposure remain issues to be investigated.

Virtual Reality for Artificial Intelligence: human-centered simulation for social science.

PubMed

Cipresso, Pietro; Riva, Giuseppe

2015-01-01

There is a long last tradition in Artificial Intelligence as use of Robots endowing human peculiarities, from a cognitive and emotional point of view, and not only in shape. Today Artificial Intelligence is more oriented to several form of collective intelligence, also building robot simulators (hardware or software) to deeply understand collective behaviors in human beings and society as a whole. Modeling has also been crucial in the social sciences, to understand how complex systems can arise from simple rules. However, while engineers' simulations can be performed in the physical world using robots, for social scientist this is impossible. For decades, researchers tried to improve simulations by endowing artificial agents with simple and complex rules that emulated human behavior also by using artificial intelligence (AI). To include human beings and their real intelligence within artificial societies is now the big challenge. We present an hybrid (human-artificial) platform where experiments can be performed by simulated artificial worlds in the following manner: 1) agents' behaviors are regulated by the behaviors shown in Virtual Reality involving real human beings exposed to specific situations to simulate, and 2) technology transfers these rules into the artificial world. These form a closed-loop of real behaviors inserted into artificial agents, which can be used to study real society.

Rivaroxaban real-world evidence: Validating safety and effectiveness in clinical practice.

PubMed

Beyer-Westendorf, Jan; Camm, A John; Coleman, Craig I; Tamayo, Sally

2016-09-28

Randomised controlled trials (RCTs) are considered the gold standard of clinical research as they use rigorous methodologies, detailed protocols, pre-specified statistical analyses and well-defined patient cohorts. However, RCTs do not take into account the complexity of real-world clinical decision-making. To tackle this, real-world data are being increasingly used to evaluate the long-term safety and effectiveness of a given therapy in routine clinical practice and in patients who may not be represented in RCTs, addressing key clinical questions that may remain. Real-world evidence plays a substantial role in supporting the use of non-vitamin K antagonist (VKA) oral anticoagulants (NOACs) in clinical practice. By providing data on patient profiles and the use of anticoagulation therapies in routine clinical practice, real-world evidence expands the current awareness of NOACs, helping to ensure that clinicians are well-informed on their use to implement patient-tailored clinical decisions. There are various issues with current anticoagulation strategies, including under- or overtreatment and frequent monitoring with VKAs. Real-world studies have demonstrated that NOAC use is increasing (Dresden NOAC registry and Global Anticoagulant Registry in the FIELD-AF [GARFIELD-AF]), as well as reaffirming the safety and effectiveness of rivaroxaban previously observed in RCTs (XArelto on preveNtion of sTroke and non-central nervoUS system systemic embolism in patients with non-valvular atrial fibrillation [XANTUS] and IMS Disease Analyzer). This article will describe the latest updates in real-world evidence across a variety of methodologies, such as non-interventional studies (NIS), registries and database analyses studies. It is anticipated that these studies will provide valuable clinical insights into the management of thromboembolism, and enhance the current knowledge on anticoagulant use and outcomes for patients.

Investigating the Impact of Cognitive Load and Motivation on Response Control in Relation to Delay Discounting in Children with ADHD.

PubMed

Martinelli, Mary K; Mostofsky, Stewart H; Rosch, Keri S

2017-10-01

Attention-deficit/hyperactivity disorder (ADHD) is characterized by deficits in impulse control across a range of behaviors, from simple actions to those involving complex decision-making (e.g., preference for smaller-sooner versus larger later rewards). This study investigated whether changes in motor response control with increased cognitive load and motivational contingencies are associated with decision-making in the form of delay discounting among 8-12 year old children with and without ADHD. Children with ADHD (n = 26; 8 girls) and typically developing controls (n = 40; 11 girls) completed a standard go/no-go (GNG) task, a GNG task with motivational contingencies, a GNG task with increased cognitive load, and two measures of delay discounting: a real-time task in which the delays and immediately consumable rewards are experienced in real-time, and a classic task involving choices about money at longer delays. Children with ADHD, particularly girls, exhibited greater delay discounting than controls during the real-time discounting task, whereas diagnostic groups did not significantly differ on the classic discounting task. The effect of cognitive load on response control was uniquely associated with greater discounting on the real-time task for children with ADHD, but not for control children. The effect of motivational contingencies on response control was not significantly associated with delay discounting for either diagnostic group. The findings from this study help to inform our understanding of the factors that influence deficient self-control in ADHD, suggesting that impairments in cognitive control may contribute to greater delay discounting in ADHD.

Generating realistic environments for cyber operations development, testing, and training

NASA Astrophysics Data System (ADS)

Berk, Vincent H.; Gregorio-de Souza, Ian; Murphy, John P.

2012-06-01

Training eective cyber operatives requires realistic network environments that incorporate the structural and social complexities representative of the real world. Network trac generators facilitate repeatable experiments for the development, training and testing of cyber operations. However, current network trac generators, ranging from simple load testers to complex frameworks, fail to capture the realism inherent in actual environments. In order to improve the realism of network trac generated by these systems, it is necessary to quantitatively measure the level of realism in generated trac with respect to the environment being mimicked. We categorize realism measures into statistical, content, and behavioral measurements, and propose various metrics that can be applied at each level to indicate how eectively the generated trac mimics the real world.

Unscrambling Jumbled Sentences: An Authentic Task for English Language Assessment?

ERIC Educational Resources Information Center

Lanteigne, Betty

2017-01-01

Jumbled sentence items in language assessment have been criticized by some authors as inauthentic. However, unscrambling jumbled sentences is a common occurrence in real-world communication in English as a lingua franca. Naturalistic inquiry identified 54 instances of jumbled sentence use in daily life in Dubai/Sharjah, where English is widely…

Development of an Online Orientation for an Instructional Technology Masters Program

ERIC Educational Resources Information Center

Dixon, Michael; Beveridge, Pamela; Farrior, Charlotte; Williams, Beth Ann; Sugar, William; Brown, Abbie

2012-01-01

Four graduate students were tasked with creating a real-world solution to a problem faced by the instructional technology masters program in which they were participating. While taking an online course in multimedia instructional product development, part of East Carolina University's Masters of Science in Instructional Technology degree program,…

Long-Term Memory Biases Auditory Spatial Attention

ERIC Educational Resources Information Center

Zimmermann, Jacqueline F.; Moscovitch, Morris; Alain, Claude

2017-01-01

Long-term memory (LTM) has been shown to bias attention to a previously learned visual target location. Here, we examined whether memory-predicted spatial location can facilitate the detection of a faint pure tone target embedded in real world audio clips (e.g., soundtrack of a restaurant). During an initial familiarization task, participants…

An Assessment of Remote Laboratory Experiments in Radio Communication

ERIC Educational Resources Information Center

Gampe, Andreas; Melkonyan, Arsen; Pontual, Murillo; Akopian, David

2014-01-01

Today's electrical and computer engineering graduates need marketable skills to work with electronic devices. Hands-on experiments prepare students to deal with real-world problems and help them to comprehend theoretical concepts and relate these to practical tasks. However, shortage of equipment, high costs, and a lack of human resources for…

Utility of Policy Capturing as an Approach to Graduate Admissions Decision Making.

ERIC Educational Resources Information Center

Schmidt, Frank L.; And Others

1978-01-01

The present study examined and evaluated the application of linear policy-capturing models to the real-world decision task of graduate admissions. Utility of the policy-capturing models was great enough to be of practical significance, and least-squares weights showed no predictive advantage over equal weights. (Author/CTM)

Problem Solving in All Seasons: Prekindergarten-Grade 2

ERIC Educational Resources Information Center

Markworth, Kim; McCool, Jenni; Kosiak, Jennifer

2015-01-01

Holidays and seasonal activities provide excitement and a change of pace for teachers and students alike. They also offer perfect backdrops for mathematical tasks that can be related to other topics and themes in the classroom. "Problem Solving in All Seasons, Prekindergarten-Grade 2" delivers thirty-two appealing, real-world situations,…

Sowing the Seeds of Creativity

ERIC Educational Resources Information Center

Briten, Elizabeth

2006-01-01

The exciting world of plants may be something of a mystery to many children, and the often-dry content of a curriculum taught indoors inhibits real understanding of many complex biological processes. Moving outdoors opens up an unexplored world and presents rich opportunities for imaginative learning. The "Life processes and living…

Echo state networks with filter neurons and a delay&sum readout.

PubMed

Holzmann, Georg; Hauser, Helmut

2010-03-01

Echo state networks (ESNs) are a novel approach to recurrent neural network training with the advantage of a very simple and linear learning algorithm. It has been demonstrated that ESNs outperform other methods on a number of benchmark tasks. Although the approach is appealing, there are still some inherent limitations in the original formulation. Here we suggest two enhancements of this network model. First, the previously proposed idea of filters in neurons is extended to arbitrary infinite impulse response (IIR) filter neurons. This enables such networks to learn multiple attractors and signals at different timescales, which is especially important for modeling real-world time series. Second, a delay&sum readout is introduced, which adds trainable delays in the synaptic connections of output neurons and therefore vastly improves the memory capacity of echo state networks. It is shown in commonly used benchmark tasks and real-world examples, that this new structure is able to significantly outperform standard ESNs and other state-of-the-art models for nonlinear dynamical system modeling. Copyright 2009 Elsevier Ltd. All rights reserved.

Effects of noise and task loading on a communication task loading on a communication task

NASA Astrophysics Data System (ADS)

Orrell, Dean H., II

Previous research had shown the effect of noise on a single communication task. This research has been criticized as not being representative of a real world situation since subjects allocated all of their attention to only one task. In the present study, the effect of adding a loading task to a standard noise-communication paradigm was investigated. Subjects performed both a communication task (Modified Rhyme Test; House et al. 1965) and a short term memory task (Sternberg, 1969) in simulated levels of aircraft noise (95, 105 and 115 dB overall sound pressure level (OASPL)). Task loading was varied with Sternberg's task by requiring subjects to memorize one, four, or six alphanumeric characters. Simulated aircraft noise was varied between levels of 95, 105 and 115 dB OASPL using a pink noise source. Results show that the addition of Sternberg's task and little effect on the intelligibility of the communication task while response time for the communication task increased.

A path model investigation of neurocognition, theory of mind, social competence, negative symptoms and real-world functioning in schizophrenia.

PubMed

Couture, Shannon M; Granholm, Eric L; Fish, Scott C

2011-02-01

Problems in real-world functioning are pervasive in schizophrenia and much recent effort has been devoted to uncovering factors which contribute to poor functioning. The goal of this study was to examine the role of four such factors: social cognition (theory of mind), neurocognition, negative symptoms, and functional capacity (social competence). 178 individuals with schizophrenia or schizoaffective disorder completed measures of theory of mind, neurocognition, negative symptoms, social competence, and self-reported functioning. Path models sought to determine the relationships among these variables. Theory of mind as indexed by the Hinting Task partially mediated the relationship between neurocognition and social competence, and negative symptoms and social competence demonstrated significant direct paths with self-reported functioning. Study results suggest theory of mind serves as an important mediator in addition to previously investigated social cognitive domains of emotional and social perception. The current study also highlights the need to determine variables which mediate the relationship between functional capacity and real-world functioning. Copyright © 2010 Elsevier B.V. All rights reserved.

Characterization of children's decision making: sensitivity to punishment frequency, not task complexity.

PubMed

Crone, Eveline A; Bunge, Silvia A; Latenstein, Heleen; van der Molen, Maurits W

2005-06-01

On a gambling task that models real-life decision making, children between ages 7 and 12 perform like patients with bilateral lesions of the ventromedial prefrontal cortex (VMPFC), opting for choices that yield high immediate gains in spite of higher future losses (Crone & Van der Molen, 2004). The current study set out to characterize developmental changes in decision making by varying task complexity and punishment frequency. Three age groups (7-9 years, 10-12 years, 13-15 years) performed two versions of a computerized variant of the original Iowa gambling task. Task complexity was manipulated by varying the number of choices participants could make. Punishment frequency was manipulated by varying the frequency of delayed punishment. Results showed a developmental increase in the sensitivity to future consequences, which was present only when the punishment was presented infrequently. These results could not be explained by differential sensitivity to task complexity, hypersensitivity to reward, or failure to switch response set after receiving punishment. There was a general pattern of boys outperforming girls by making more advantageous choices over the course of the task. In conclusion, 7-12-year-old children--like VMPFC patients--appear myopic about the future except when the potential for future punishment is high.

Electroencephalography(EEG)-based instinctive brain-control of a quadruped locomotion robot.

PubMed

Jia, Wenchuan; Huang, Dandan; Luo, Xin; Pu, Huayan; Chen, Xuedong; Bai, Ou

2012-01-01

Artificial intelligence and bionic control have been applied in electroencephalography (EEG)-based robot system, to execute complex brain-control task. Nevertheless, due to technical limitations of the EEG decoding, the brain-computer interface (BCI) protocol is often complex, and the mapping between the EEG signal and the practical instructions lack of logic associated, which restrict the user's actual use. This paper presents a strategy that can be used to control a quadruped locomotion robot by user's instinctive action, based on five kinds of movement related neurophysiological signal. In actual use, the user drives or imagines the limbs/wrists action to generate EEG signal to adjust the real movement of the robot according to his/her own motor reflex of the robot locomotion. This method is easy for real use, as the user generates the brain-control signal through the instinctive reaction. By adopting the behavioral control of learning and evolution based on the proposed strategy, complex movement task may be realized by instinctive brain-control.

Boosting medical diagnostics by pooling independent judgments

PubMed Central

Kurvers, Ralf H. J. M.; Herzog, Stefan M.; Hertwig, Ralph; Krause, Jens; Carney, Patricia A.; Bogart, Andy; Argenziano, Giuseppe; Zalaudek, Iris; Wolf, Max

2016-01-01

Collective intelligence refers to the ability of groups to outperform individual decision makers when solving complex cognitive problems. Despite its potential to revolutionize decision making in a wide range of domains, including medical, economic, and political decision making, at present, little is known about the conditions underlying collective intelligence in real-world contexts. We here focus on two key areas of medical diagnostics, breast and skin cancer detection. Using a simulation study that draws on large real-world datasets, involving more than 140 doctors making more than 20,000 diagnoses, we investigate when combining the independent judgments of multiple doctors outperforms the best doctor in a group. We find that similarity in diagnostic accuracy is a key condition for collective intelligence: Aggregating the independent judgments of doctors outperforms the best doctor in a group whenever the diagnostic accuracy of doctors is relatively similar, but not when doctors’ diagnostic accuracy differs too much. This intriguingly simple result is highly robust and holds across different group sizes, performance levels of the best doctor, and collective intelligence rules. The enabling role of similarity, in turn, is explained by its systematic effects on the number of correct and incorrect decisions of the best doctor that are overruled by the collective. By identifying a key factor underlying collective intelligence in two important real-world contexts, our findings pave the way for innovative and more effective approaches to complex real-world decision making, and to the scientific analyses of those approaches. PMID:27432950

Feasibility of task-specific brain-machine interface training for upper-extremity paralysis in patients with chronic hemiparetic stroke.

PubMed

Nishimoto, Atsuko; Kawakami, Michiyuki; Fujiwara, Toshiyuki; Hiramoto, Miho; Honaga, Kaoru; Abe, Kaoru; Mizuno, Katsuhiro; Ushiba, Junichi; Liu, Meigen

2018-01-10

Brain-machine interface training was developed for upper-extremity rehabilitation for patients with severe hemiparesis. Its clinical application, however, has been limited because of its lack of feasibility in real-world rehabilitation settings. We developed a new compact task-specific brain-machine interface system that enables task-specific training, including reach-and-grasp tasks, and studied its clinical feasibility and effectiveness for upper-extremity motor paralysis in patients with stroke. Prospective beforeâ€"after study. Twenty-six patients with severe chronic hemiparetic stroke. Participants were trained with the brain-machine interface system to pick up and release pegs during 40-min sessions and 40 min of standard occupational therapy per day for 10 days. Fugl-Meyer upper-extremity motor (FMA) and Motor Activity Log-14 amount of use (MAL-AOU) scores were assessed before and after the intervention. To test its feasibility, 4 occupational therapists who operated the system for the first time assessed it with the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST) 2.0. FMA and MAL-AOU scores improved significantly after brain-machine interface training, with the effect sizes being medium and large, respectively (p<0.01, d=0.55; p<0.01, d=0.88). QUEST effectiveness and safety scores showed feasibility and satisfaction in the clinical setting. Our newly developed compact brain-machine interface system is feasible for use in real-world clinical settings.

Effects of Cognitive Load on Driving Performance: The Cognitive Control Hypothesis.

PubMed

Engström, Johan; Markkula, Gustav; Victor, Trent; Merat, Natasha

2017-08-01

The objective of this paper was to outline an explanatory framework for understanding effects of cognitive load on driving performance and to review the existing experimental literature in the light of this framework. Although there is general consensus that taking the eyes off the forward roadway significantly impairs most aspects of driving, the effects of primarily cognitively loading tasks on driving performance are not well understood. Based on existing models of driver attention, an explanatory framework was outlined. This framework can be summarized in terms of the cognitive control hypothesis: Cognitive load selectively impairs driving subtasks that rely on cognitive control but leaves automatic performance unaffected. An extensive literature review was conducted wherein existing results were reinterpreted based on the proposed framework. It was demonstrated that the general pattern of experimental results reported in the literature aligns well with the cognitive control hypothesis and that several apparent discrepancies between studies can be reconciled based on the proposed framework. More specifically, performance on nonpracticed or inherently variable tasks, relying on cognitive control, is consistently impaired by cognitive load, whereas the performance on automatized (well-practiced and consistently mapped) tasks is unaffected and sometimes even improved. Effects of cognitive load on driving are strongly selective and task dependent. The present results have important implications for the generalization of results obtained from experimental studies to real-world driving. The proposed framework can also serve to guide future research on the potential causal role of cognitive load in real-world crashes.

Toward Efficient Team Formation for Crowdsourcing in Noncooperative Social Networks.

PubMed

Wang, Wanyuan; Jiang, Jiuchuan; An, Bo; Jiang, Yichuan; Chen, Bing

2017-12-01

Crowdsourcing has become a popular service computing paradigm for requesters to integrate the ubiquitous human-intelligence services for tasks that are difficult for computers but trivial for humans. This paper focuses on crowdsourcing complex tasks by team formation in social networks (SNs) where a requester connects to a large number of workers. A good indicator of efficient team collaboration is the social connection among workers. Most previous social team formation approaches, however, either assume that the requester can maintain information of all workers and can directly communicate with them to build teams, or assume that the workers are cooperative and be willing to join the specific team built by the requester, both of which are impractical in many real situations. To this end, this paper first models each worker as a selfish entity, where the requester prefers to hire inexpensive workers that require less payment and workers prefer to join the profitable teams where they can gain high revenue. Within the noncooperative SNs, a distributed negotiation-based team formation mechanism is designed for the requester to decide which worker to hire and for the worker to decide which team to join and how much should be paid for his skill service provision. The proposed social team formation approach can always build collaborative teams by allowing team members to form a connected graph such that they can work together efficiently. Finally, we conduct a set of experiments on real dataset of workers to evaluate the effectiveness of our approach. The experimental results show that our approach can: 1) preserve considerable social welfare by comparing the benchmark centralized approaches and 2) form the profitable teams within less negotiation time by comparing the traditional distributed approaches, making our approach a more economic option for real-world applications.

Selective Influence of Circadian Modulation and Task Characteristics on Motor Imagery Time

ERIC Educational Resources Information Center

Debarnot, Ursula; Sahraoui, Djafar; Champely, Stephane; Collet, Christian; Guillot, Aymeric

2012-01-01

In this study, we examined the effect of circadian modulation on motor imagery (MI) time while also considering the effects of task complexity and duration. The ability to imagine in real time was influenced by circadian modulation in a simple walking condition, with longer MI times in the morning and evening sessions. By contrast, there was no…

Direct manipulation of virtual objects

NASA Astrophysics Data System (ADS)

Nguyen, Long K.

Interacting with a Virtual Environment (VE) generally requires the user to correctly perceive the relative position and orientation of virtual objects. For applications requiring interaction in personal space, the user may also need to accurately judge the position of the virtual object relative to that of a real object, for example, a virtual button and the user's real hand. This is difficult since VEs generally only provide a subset of the cues experienced in the real world. Complicating matters further, VEs presented by currently available visual displays may be inaccurate or distorted due to technological limitations. Fundamental physiological and psychological aspects of vision as they pertain to the task of object manipulation were thoroughly reviewed. Other sensory modalities -- proprioception, haptics, and audition -- and their cross-interactions with each other and with vision are briefly discussed. Visual display technologies, the primary component of any VE, were canvassed and compared. Current applications and research were gathered and categorized by different VE types and object interaction techniques. While object interaction research abounds in the literature, pockets of research gaps remain. Direct, dexterous, manual interaction with virtual objects in Mixed Reality (MR), where the real, seen hand accurately and effectively interacts with virtual objects, has not yet been fully quantified. An experimental test bed was designed to provide the highest accuracy attainable for salient visual cues in personal space. Optical alignment and user calibration were carefully performed. The test bed accommodated the full continuum of VE types and sensory modalities for comprehensive comparison studies. Experimental designs included two sets, each measuring depth perception and object interaction. The first set addressed the extreme end points of the Reality-Virtuality (R-V) continuum -- Immersive Virtual Environment (IVE) and Reality Environment (RE). This validated, linked, and extended several previous research findings, using one common test bed and participant pool. The results provided a proven method and solid reference points for further research. The second set of experiments leveraged the first to explore the full R-V spectrum and included additional, relevant sensory modalities. It consisted of two full-factorial experiments providing for rich data and key insights into the effect of each type of environment and each modality on accuracy and timeliness of virtual object interaction. The empirical results clearly showed that mean depth perception error in personal space was less than four millimeters whether the stimuli presented were real, virtual, or mixed. Likewise, mean error for the simple task of pushing a button was less than four millimeters whether the button was real or virtual. Mean task completion time was less than one second. Key to the high accuracy and quick task performance time observed was the correct presentation of the visual cues, including occlusion, stereoscopy, accommodation, and convergence. With performance results already near optimal level with accurate visual cues presented, adding proprioception, audio, and haptic cues did not significantly improve performance. Recommendations for future research include enhancement of the visual display and further experiments with more complex tasks and additional control variables.

A simple model clarifies the complicated relationships of complex networks

PubMed Central

Zheng, Bojin; Wu, Hongrun; Kuang, Li; Qin, Jun; Du, Wenhua; Wang, Jianmin; Li, Deyi

2014-01-01

Real-world networks such as the Internet and WWW have many common traits. Until now, hundreds of models were proposed to characterize these traits for understanding the networks. Because different models used very different mechanisms, it is widely believed that these traits origin from different causes. However, we find that a simple model based on optimisation can produce many traits, including scale-free, small-world, ultra small-world, Delta-distribution, compact, fractal, regular and random networks. Moreover, by revising the proposed model, the community-structure networks are generated. By this model and the revised versions, the complicated relationships of complex networks are illustrated. The model brings a new universal perspective to the understanding of complex networks and provide a universal method to model complex networks from the viewpoint of optimisation. PMID:25160506

Change Detection: Training and Transfer

PubMed Central

Gaspar, John G.; Neider, Mark B.; Simons, Daniel J.; McCarley, Jason S.; Kramer, Arthur F.

2013-01-01

Observers often fail to notice even dramatic changes to their environment, a phenomenon known as change blindness. If training could enhance change detection performance in general, then it might help to remedy some real-world consequences of change blindness (e.g. failing to detect hazards while driving). We examined whether adaptive training on a simple change detection task could improve the ability to detect changes in untrained tasks for young and older adults. Consistent with an effective training procedure, both young and older adults were better able to detect changes to trained objects following training. However, neither group showed differential improvement on untrained change detection tasks when compared to active control groups. Change detection training led to improvements on the trained task but did not generalize to other change detection tasks. PMID:23840775

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pin, F.G.

Outdoor sensor-based operation of autonomous robots has revealed to be an extremely challenging problem, mainly because of the difficulties encountered when attempting to represent the many uncertainties which are always present in the real world. These uncertainties are primarily due to sensor imprecisions and unpredictability of the environment, i.e., lack of full knowledge of the environment characteristics and dynamics. Two basic principles, or philosophies, and their associated methodologies are proposed in an attempt to remedy some of these difficulties. The first principle is based on the concept of ``minimal model`` for accomplishing given tasks and proposes to utilize only themore » minimum level of information and precision necessary to accomplish elemental functions of complex tasks. This approach diverges completely from the direction taken by most artificial vision studies which conventionally call for crisp and detailed analysis of every available component in the perception data. The paper will first review the basic concepts of this approach and will discuss its pragmatic feasibility when embodied in a behaviorist framework. The second principle which is proposed deals with implicit representation of uncertainties using Fuzzy Set Theory-based approximations and approximate reasoning, rather than explicit (crisp) representation through calculation and conventional propagation techniques. A framework which merges these principles and approaches is presented, and its application to the problem of sensor-based outdoor navigation of a mobile robot is discussed. Results of navigation experiments with a real car in actual outdoor environments are also discussed to illustrate the feasibility of the overall concept.« less

Dynamic, continuous multitasking training leads to task-specific improvements but does not transfer across action selection tasks

NASA Astrophysics Data System (ADS)

Bender, Angela D.; Filmer, Hannah L.; Naughtin, Claire K.; Dux, Paul E.

2017-12-01

The ability to perform multiple tasks concurrently is an ever-increasing requirement in our information-rich world. Despite this, multitasking typically compromises performance due to the processing limitations associated with cognitive control and decision-making. While intensive dual-task training is known to improve multitasking performance, only limited evidence suggests that training-related performance benefits can transfer to untrained tasks that share overlapping processes. In the real world, however, coordinating and selecting several responses within close temporal proximity will often occur in high-interference environments. Over the last decade, there have been notable reports that training on video action games that require dynamic multitasking in a demanding environment can lead to transfer effects on aspects of cognition such as attention and working memory. Here, we asked whether continuous and dynamic multitasking training extends benefits to tasks that are theoretically related to the trained tasks. To examine this issue, we asked a group of participants to train on a combined continuous visuomotor tracking task and a perceptual discrimination task for six sessions, while an active control group practiced the component tasks in isolation. A battery of tests measuring response selection, response inhibition, and spatial attention was administered before and immediately after training to investigate transfer. Multitasking training resulted in substantial, task-specific gains in dual-task ability, but there was no evidence that these benefits generalized to other action control tasks. The findings suggest that training on a combined visuomotor tracking and discrimination task results in task-specific benefits but provides no additional value for untrained action selection tasks.

Translational Cognition for Decision Support in Critical Care Environments: A Review

PubMed Central

Patel, Vimla L.; Zhang, Jiajie; Yoskowitz, Nicole A.; Green, Robert; Sayan, Osman R.

2008-01-01

The dynamic and distributed work environment in critical care requires a high level of collaboration among clinical team members and a sophisticated task coordination system to deliver safe, timely and effective care. A complex cognitive system underlies the decision-making process in such cooperative workplaces. This methodological review paper addresses the issues of translating cognitive research to clinical practice with a specific focus on decision-making in critical care, and the role of information and communication technology to aid in such decisions. Examples are drawn from studies of critical care in our own research laboratories. Critical care, in this paper, includes both intensive (inpatient) and emergency (outpatient) care. We define translational cognition as the research on basic and applied cognitive issues that contribute to our understanding of how information is stored, retrieved and used for problem-solving and decision-making. The methods and findings are discussed in the context of constraints on decision-making in real world complex environments and implications for supporting the design and evaluation of decision support tools for critical care health providers. PMID:18343731

Translational cognition for decision support in critical care environments: a review.

PubMed

Patel, Vimla L; Zhang, Jiajie; Yoskowitz, Nicole A; Green, Robert; Sayan, Osman R

2008-06-01

The dynamic and distributed work environment in critical care requires a high level of collaboration among clinical team members and a sophisticated task coordination system to deliver safe, timely and effective care. A complex cognitive system underlies the decision-making process in such cooperative workplaces. This methodological review paper addresses the issues of translating cognitive research to clinical practice with a specific focus on decision-making in critical care, and the role of information and communication technology to aid in such decisions. Examples are drawn from studies of critical care in our own research laboratories. Critical care, in this paper, includes both intensive (inpatient) and emergency (outpatient) care. We define translational cognition as the research on basic and applied cognitive issues that contribute to our understanding of how information is stored, retrieved and used for problem-solving and decision-making. The methods and findings are discussed in the context of constraints on decision-making in real-world complex environments and implications for supporting the design and evaluation of decision support tools for critical care health providers.

Cathodal Transcranial Direct Current Stimulation Over Left Dorsolateral Prefrontal Cortex Area Promotes Implicit Motor Learning in a Golf Putting Task.

PubMed

Zhu, Frank F; Yeung, Andrew Y; Poolton, Jamie M; Lee, Tatia M C; Leung, Gilberto K K; Masters, Rich S W

2015-01-01

Implicit motor learning is characterized by low dependence on working memory and stable performance despite stress, fatigue, or multi-tasking. However, current paradigms for implicit motor learning are based on behavioral interventions that are often task-specific and limited when applied in practice. To investigate whether cathodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) area during motor learning suppressed working memory activity and reduced explicit verbal-analytical involvement in movement control, thereby promoting implicit motor learning. Twenty-seven healthy individuals practiced a golf putting task during a Training Phase while receiving either real cathodal tDCS stimulation over the left DLPFC area or sham stimulation. Their performance was assessed during a Test phase on another day. Verbal working memory capacity was assessed before and after the Training Phase, and before the Test Phase. Compared to sham stimulation, real stimulation suppressed verbal working memory activity after the Training Phase, but enhanced golf putting performance during the Training Phase and the Test Phase, especially when participants were required to multi-task. Cathodal tDCS over the left DLPFC may foster implicit motor learning and performance in complex real-life motor tasks that occur during sports, surgery or motor rehabilitation. Copyright © 2015 Elsevier Inc. All rights reserved.

Enabling complex genetic circuits to respond to extrinsic environmental signals.

PubMed

Hoynes-O'Connor, Allison; Shopera, Tatenda; Hinman, Kristina; Creamer, John Philip; Moon, Tae Seok

2017-07-01

Genetic circuits have the potential to improve a broad range of metabolic engineering processes and address a variety of medical and environmental challenges. However, in order to engineer genetic circuits that can meet the needs of these real-world applications, genetic sensors that respond to relevant extrinsic and intrinsic signals must be implemented in complex genetic circuits. In this work, we construct the first AND and NAND gates that respond to temperature and pH, two signals that have relevance in a variety of real-world applications. A previously identified pH-responsive promoter and a temperature-responsive promoter were extracted from the E. coli genome, characterized, and modified to suit the needs of the genetic circuits. These promoters were combined with components of the type III secretion system in Salmonella typhimurium and used to construct a set of AND gates with up to 23-fold change. Next, an antisense RNA was integrated into the circuit architecture to invert the logic of the AND gate and generate a set of NAND gates with up to 1168-fold change. These circuits provide the first demonstration of complex pH- and temperature-responsive genetic circuits, and lay the groundwork for the use of similar circuits in real-world applications. Biotechnol. Bioeng. 2017;114: 1626-1631. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Simultaneous personnel and vehicle shift scheduling in the waste management sector.

PubMed

Ghiani, Gianpaolo; Guerriero, Emanuela; Manni, Andrea; Manni, Emanuele; Potenza, Agostino

2013-07-01

Urban waste management is becoming an increasingly complex task, absorbing a huge amount of resources, and having a major environmental impact. The design of a waste management system consists in various activities, and one of these is related to the definition of shift schedules for both personnel and vehicles. This activity has a great incidence on the tactical and operational cost for companies. In this paper, we propose an integer programming model to find an optimal solution to the integrated problem. The aim is to determine optimal schedules at minimum cost. Moreover, we design a fast and effective heuristic to face large-size problems. Both approaches are tested on data from a real-world case in Southern Italy and compared to the current practice utilized by the company managing the service, showing that simultaneously solving these problems can lead to significant monetary savings. Copyright © 2013 Elsevier Ltd. All rights reserved.

Learning classification with auxiliary probabilistic information

PubMed Central

Nguyen, Quang; Valizadegan, Hamed; Hauskrecht, Milos

2012-01-01

Finding ways of incorporating auxiliary information or auxiliary data into the learning process has been the topic of active data mining and machine learning research in recent years. In this work we study and develop a new framework for classification learning problem in which, in addition to class labels, the learner is provided with an auxiliary (probabilistic) information that reflects how strong the expert feels about the class label. This approach can be extremely useful for many practical classification tasks that rely on subjective label assessment and where the cost of acquiring additional auxiliary information is negligible when compared to the cost of the example analysis and labelling. We develop classification algorithms capable of using the auxiliary information to make the learning process more efficient in terms of the sample complexity. We demonstrate the benefit of the approach on a number of synthetic and real world data sets by comparing it to the learning with class labels only. PMID:25309141

A Java application for tissue section image analysis.

PubMed

Kamalov, R; Guillaud, M; Haskins, D; Harrison, A; Kemp, R; Chiu, D; Follen, M; MacAulay, C

2005-02-01

The medical industry has taken advantage of Java and Java technologies over the past few years, in large part due to the language's platform-independence and object-oriented structure. As such, Java provides powerful and effective tools for developing tissue section analysis software. The background and execution of this development are discussed in this publication. Object-oriented structure allows for the creation of "Slide", "Unit", and "Cell" objects to simulate the corresponding real-world objects. Different functions may then be created to perform various tasks on these objects, thus facilitating the development of the software package as a whole. At the current time, substantial parts of the initially planned functionality have been implemented. Getafics 1.0 is fully operational and currently supports a variety of research projects; however, there are certain features of the software that currently introduce unnecessary complexity and inefficiency. In the future, we hope to include features that obviate these problems.

Answer Sets in a Fuzzy Equilibrium Logic

NASA Astrophysics Data System (ADS)

Schockaert, Steven; Janssen, Jeroen; Vermeir, Dirk; de Cock, Martine

Since its introduction, answer set programming has been generalized in many directions, to cater to the needs of real-world applications. As one of the most general “classical” approaches, answer sets of arbitrary propositional theories can be defined as models in the equilibrium logic of Pearce. Fuzzy answer set programming, on the other hand, extends answer set programming with the capability of modeling continuous systems. In this paper, we combine the expressiveness of both approaches, and define answer sets of arbitrary fuzzy propositional theories as models in a fuzzification of equilibrium logic. We show that the resulting notion of answer set is compatible with existing definitions, when the syntactic restrictions of the corresponding approaches are met. We furthermore locate the complexity of the main reasoning tasks at the second level of the polynomial hierarchy. Finally, as an illustration of its modeling power, we show how fuzzy equilibrium logic can be used to find strong Nash equilibria.

Analysis of line structure in handwritten documents using the Hough transform

NASA Astrophysics Data System (ADS)

Ball, Gregory R.; Kasiviswanathan, Harish; Srihari, Sargur N.; Narayanan, Aswin

2010-01-01

In the analysis of handwriting in documents a central task is that of determining line structure of the text, e.g., number of text lines, location of their starting and end-points, line-width, etc. While simple methods can handle ideal images, real world documents have complexities such as overlapping line structure, variable line spacing, line skew, document skew, noisy or degraded images etc. This paper explores the application of the Hough transform method to handwritten documents with the goal of automatically determining global document line structure in a top-down manner which can then be used in conjunction with a bottom-up method such as connected component analysis. The performance is significantly better than other top-down methods, such as the projection profile method. In addition, we evaluate the performance of skew analysis by the Hough transform on handwritten documents.

Applications suitable for unmanned and autonomous missions utilizing the Tactical Amphibious Ground Support (TAGS) platform

NASA Astrophysics Data System (ADS)

Lewis, Paul J.; Torrie, Mitchel R.; Omilon, Paul M.

2004-09-01

The value of unmanned vehicles is directly related to the applications to which it can be successfully applied. Many applications exist and have been identified as suitable for unmanned vehicles, especially those involving dull, dirty, difficult, and dangerous tasks. This paper will highlight applications, missions, and capabilities that have been demonstrated on the TAGS platform to date as well as future application and mission considerations. When evaluating real world applications for this type of vehicle, one must take into account and balance the complexity inherent to the control and safeguarding requirements of a large autonomous ground vehicle with the simplicity required for commercial or military field use. In addition, suitability for a particular application may be limited by the size, weight, fuel consumption, reliability, terrain crossing capability, and other abilities of a vehicle and the intelligent software system and sensors commanding it.

The unconscious regulation of emotion: nonconscious reappraisal goals modulate emotional reactivity.

PubMed

Williams, Lawrence E; Bargh, John A; Nocera, Christopher C; Gray, Jeremy R

2009-12-01

People often encounter difficulty when making conscious attempts to regulate their emotions. We propose that nonconscious self-regulatory processes may be of help in these difficult circumstances because nonconscious processes are not subject to the same set of limitations as are conscious processes. Two experiments examined the effects of nonconsciously operating goals on people's emotion regulatory success. In Experiment 1, participants engaged in an anxiety-eliciting task. Participants who had a reappraisal emotion control goal primed and operating nonconsciously achieved the same decrease in physiological reactivity as those explicitly instructed to reappraise. In Experiment 2, the effect of nonconscious reappraisal priming on physiological reactivity was shown to be most pronounced for those who do not habitually use reappraisal strategies. The findings highlight the potential importance of nonconscious goals for facilitating emotional control in complex real-world environments and have implications for contemporary models of emotion regulation.

Reinforcement learning and episodic memory in humans and animals: an integrative framework

PubMed Central

Gershman, Samuel J.; Daw, Nathaniel D.

2018-01-01

We review the psychology and neuroscience of reinforcement learning (RL), which has witnessed significant progress in the last two decades, enabled by the comprehensive experimental study of simple learning and decision-making tasks. However, the simplicity of these tasks misses important aspects of reinforcement learning in the real world: (i) State spaces are high-dimensional, continuous, and partially observable; this implies that (ii) data are relatively sparse: indeed precisely the same situation may never be encountered twice; and also that (iii) rewards depend on long-term consequences of actions in ways that violate the classical assumptions that make RL tractable. A seemingly distinct challenge is that, cognitively, these theories have largely connected with procedural and semantic memory: how knowledge about action values or world models extracted gradually from many experiences can drive choice. This misses many aspects of memory related to traces of individual events, such as episodic memory. We suggest that these two gaps are related. In particular, the computational challenges can be dealt with, in part, by endowing RL systems with episodic memory, allowing them to (i) efficiently approximate value functions over complex state spaces, (ii) learn with very little data, and (iii) bridge long-term dependencies between actions and rewards. We review the computational theory underlying this proposal and the empirical evidence to support it. Our proposal suggests that the ubiquitous and diverse roles of memory in RL may function as part of an integrated learning system. PMID:27618944

The R-Shell approach - Using scheduling agents in complex distributed real-time systems

NASA Technical Reports Server (NTRS)

Natarajan, Swaminathan; Zhao, Wei; Goforth, Andre

1993-01-01

Large, complex real-time systems such as space and avionics systems are extremely demanding in their scheduling requirements. The current OS design approaches are quite limited in the capabilities they provide for task scheduling. Typically, they simply implement a particular uniprocessor scheduling strategy and do not provide any special support for network scheduling, overload handling, fault tolerance, distributed processing, etc. Our design of the R-Shell real-time environment fcilitates the implementation of a variety of sophisticated but efficient scheduling strategies, including incorporation of all these capabilities. This is accomplished by the use of scheduling agents which reside in the application run-time environment and are responsible for coordinating the scheduling of the application.

The role of rehearsal in a novel call center-type task.

PubMed

Perham, Nick; Banbury, Simon

2012-01-01

Laboratory research has long demonstrated the disruptive effects of background sound to task performance yet the real-world implications of such effects are less well known. We report two experiments that demonstrate the importance of the role of rehearsal to a novel call center-type task. In Experiment 1, performance of a novel train timetable task-in which participants identified four train journeys following presentation of train journey information-was disrupted by realistic office noise. However, in Experiment 2, when the need for rehearsal was reduced by presenting the information and the timetable at the same time, no disruption occurred . Results are discussed in terms of interference-by-process and interference-by-content approaches to short-term memory.

Assessing Students' Proficiency in Math and Science

ERIC Educational Resources Information Center

Judd, Thomas P.; Keith, Bruce

2007-01-01

The U.S. Military Academy (USMA) at West Point is responsible for developing in its graduates literacy in the sciences that renders them capable of solving complex real-world problems. Throughout their careers as officers in the military, graduates will be called upon to view the physical world in a disciplined and objective manner, with an…

Integrating planning and reactive control

NASA Technical Reports Server (NTRS)

Wilkins, David E.; Myers, Karen L.

1994-01-01

Our research is developing persistent agents that can achieve complex tasks in dynamic and uncertain environments. We refer to such agents as taskable, reactive agents. An agent of this type requires a number of capabilities. The ability to execute complex tasks necessitates the use of strategic plans for accomplishing tasks; hence, the agent must be able to synthesize new plans at run time. The dynamic nature of the environment requires that the agent be able to deal with unpredictable changes in its world. As such, agents must be able to react to unanticipated events by taking appropriate actions in a timely manner, while continuing activities that support current goals. The unpredictability of the world could lead to failure of plans generated for individual tasks. Agents must have the ability to recover from failures by adapting their activities to the new situation, or replanning if the world changes sufficiently. Finally, the agent should be able to perform in the face of uncertainty. The Cypress system, described here, provides a framework for creating taskable, reactive agents. Several features distinguish our approach: (1) the generation and execution of complex plans with parallel actions; (2) the integration of goal-driven and event driven activities during execution; (3) the use of evidential reasoning for dealing with uncertainty; and (4) the use of replanning to handle run-time execution problems. Our model for a taskable, reactive agent has two main intelligent components, an executor and a planner. The two components share a library of possible actions that the system can take. The library encompasses a full range of action representations, including plans, planning operators, and executable procedures such as predefined standard operating procedures (SOP's). These three classes of actions span multiple levels of abstraction.

Integrating planning and reactive control

NASA Astrophysics Data System (ADS)

Wilkins, David E.; Myers, Karen L.

1994-10-01

Our research is developing persistent agents that can achieve complex tasks in dynamic and uncertain environments. We refer to such agents as taskable, reactive agents. An agent of this type requires a number of capabilities. The ability to execute complex tasks necessitates the use of strategic plans for accomplishing tasks; hence, the agent must be able to synthesize new plans at run time. The dynamic nature of the environment requires that the agent be able to deal with unpredictable changes in its world. As such, agents must be able to react to unanticipated events by taking appropriate actions in a timely manner, while continuing activities that support current goals. The unpredictability of the world could lead to failure of plans generated for individual tasks. Agents must have the ability to recover from failures by adapting their activities to the new situation, or replanning if the world changes sufficiently. Finally, the agent should be able to perform in the face of uncertainty. The Cypress system, described here, provides a framework for creating taskable, reactive agents. Several features distinguish our approach: (1) the generation and execution of complex plans with parallel actions; (2) the integration of goal-driven and event driven activities during execution; (3) the use of evidential reasoning for dealing with uncertainty; and (4) the use of replanning to handle run-time execution problems. Our model for a taskable, reactive agent has two main intelligent components, an executor and a planner. The two components share a library of possible actions that the system can take. The library encompasses a full range of action representations, including plans, planning operators, and executable procedures such as predefined standard operating procedures (SOP's). These three classes of actions span multiple levels of abstraction.

Small-world bias of correlation networks: From brain to climate

NASA Astrophysics Data System (ADS)

Hlinka, Jaroslav; Hartman, David; Jajcay, Nikola; Tomeček, David; Tintěra, Jaroslav; Paluš, Milan

2017-03-01

Complex systems are commonly characterized by the properties of their graph representation. Dynamical complex systems are then typically represented by a graph of temporal dependencies between time series of state variables of their subunits. It has been shown recently that graphs constructed in this way tend to have relatively clustered structure, potentially leading to spurious detection of small-world properties even in the case of systems with no or randomly distributed true interactions. However, the strength of this bias depends heavily on a range of parameters and its relevance for real-world data has not yet been established. In this work, we assess the relevance of the bias using two examples of multivariate time series recorded in natural complex systems. The first is the time series of local brain activity as measured by functional magnetic resonance imaging in resting healthy human subjects, and the second is the time series of average monthly surface air temperature coming from a large reanalysis of climatological data over the period 1948-2012. In both cases, the clustering in the thresholded correlation graph is substantially higher compared with a realization of a density-matched random graph, while the shortest paths are relatively short, showing thus distinguishing features of small-world structure. However, comparable or even stronger small-world properties were reproduced in correlation graphs of model processes with randomly scrambled interconnections. This suggests that the small-world properties of the correlation matrices of these real-world systems indeed do not reflect genuinely the properties of the underlying interaction structure, but rather result from the inherent properties of correlation matrix.

Small-world bias of correlation networks: From brain to climate.

PubMed

Hlinka, Jaroslav; Hartman, David; Jajcay, Nikola; Tomeček, David; Tintěra, Jaroslav; Paluš, Milan

2017-03-01

Complex systems are commonly characterized by the properties of their graph representation. Dynamical complex systems are then typically represented by a graph of temporal dependencies between time series of state variables of their subunits. It has been shown recently that graphs constructed in this way tend to have relatively clustered structure, potentially leading to spurious detection of small-world properties even in the case of systems with no or randomly distributed true interactions. However, the strength of this bias depends heavily on a range of parameters and its relevance for real-world data has not yet been established. In this work, we assess the relevance of the bias using two examples of multivariate time series recorded in natural complex systems. The first is the time series of local brain activity as measured by functional magnetic resonance imaging in resting healthy human subjects, and the second is the time series of average monthly surface air temperature coming from a large reanalysis of climatological data over the period 1948-2012. In both cases, the clustering in the thresholded correlation graph is substantially higher compared with a realization of a density-matched random graph, while the shortest paths are relatively short, showing thus distinguishing features of small-world structure. However, comparable or even stronger small-world properties were reproduced in correlation graphs of model processes with randomly scrambled interconnections. This suggests that the small-world properties of the correlation matrices of these real-world systems indeed do not reflect genuinely the properties of the underlying interaction structure, but rather result from the inherent properties of correlation matrix.

Local spatial frequency analysis for computer vision

NASA Technical Reports Server (NTRS)

Krumm, John; Shafer, Steven A.

1990-01-01

A sense of vision is a prerequisite for a robot to function in an unstructured environment. However, real-world scenes contain many interacting phenomena that lead to complex images which are difficult to interpret automatically. Typical computer vision research proceeds by analyzing various effects in isolation (e.g., shading, texture, stereo, defocus), usually on images devoid of realistic complicating factors. This leads to specialized algorithms which fail on real-world images. Part of this failure is due to the dichotomy of useful representations for these phenomena. Some effects are best described in the spatial domain, while others are more naturally expressed in frequency. In order to resolve this dichotomy, we present the combined space/frequency representation which, for each point in an image, shows the spatial frequencies at that point. Within this common representation, we develop a set of simple, natural theories describing phenomena such as texture, shape, aliasing and lens parameters. We show these theories lead to algorithms for shape from texture and for dealiasing image data. The space/frequency representation should be a key aid in untangling the complex interaction of phenomena in images, allowing automatic understanding of real-world scenes.

Efficient weighting strategy for enhancing synchronizability of complex networks

NASA Astrophysics Data System (ADS)

Wang, Youquan; Yu, Feng; Huang, Shucheng; Tu, Juanjuan; Chen, Yan

2018-04-01

Networks with high propensity to synchronization are desired in many applications ranging from biology to engineering. In general, there are two ways to enhance the synchronizability of a network: link rewiring and/or link weighting. In this paper, we propose a new link weighting strategy based on the concept of the neighborhood subgroup. The neighborhood subgroup of a node i through node j in a network, i.e. Gi→j, means that node u belongs to Gi→j if node u belongs to the first-order neighbors of j (not include i). Our proposed weighting schema used the local and global structural properties of the networks such as the node degree, betweenness centrality and closeness centrality measures. We applied the method on scale-free and Watts-Strogatz networks of different structural properties and show the good performance of the proposed weighting scheme. Furthermore, as model networks cannot capture all essential features of real-world complex networks, we considered a number of undirected and unweighted real-world networks. To the best of our knowledge, the proposed weighting strategy outperformed the previously published weighting methods by enhancing the synchronizability of these real-world networks.

Breakdown of interdependent directed networks.

PubMed

Liu, Xueming; Stanley, H Eugene; Gao, Jianxi

2016-02-02

Increasing evidence shows that real-world systems interact with one another via dependency connectivities. Failing connectivities are the mechanism behind the breakdown of interacting complex systems, e.g., blackouts caused by the interdependence of power grids and communication networks. Previous research analyzing the robustness of interdependent networks has been limited to undirected networks. However, most real-world networks are directed, their in-degrees and out-degrees may be correlated, and they are often coupled to one another as interdependent directed networks. To understand the breakdown and robustness of interdependent directed networks, we develop a theoretical framework based on generating functions and percolation theory. We find that for interdependent Erdős-Rényi networks the directionality within each network increases their vulnerability and exhibits hybrid phase transitions. We also find that the percolation behavior of interdependent directed scale-free networks with and without degree correlations is so complex that two criteria are needed to quantify and compare their robustness: the percolation threshold and the integrated size of the giant component during an entire attack process. Interestingly, we find that the in-degree and out-degree correlations in each network layer increase the robustness of interdependent degree heterogeneous networks that most real networks are, but decrease the robustness of interdependent networks with homogeneous degree distribution and with strong coupling strengths. Moreover, by applying our theoretical analysis to real interdependent international trade networks, we find that the robustness of these real-world systems increases with the in-degree and out-degree correlations, confirming our theoretical analysis.

Beyond the audiogram: application of models of auditory fitness for duty to assess communication in the real world.

PubMed

Dubno, Judy R

2018-05-01

This manuscript provides a Commentary on a paper published in the current issue of the International Journal of Audiology and the companion paper published in Ear and Hearing by Soli et al. These papers report background, rationale and results of a novel modelling approach to assess "auditory fitness for duty," or an individual's ability to perform hearing-critical tasks related to their job, based on their likelihood of effective speech communication in the listening environment in which the task is performed.

Student Perceptions of a Recreation Trail Assignment as a Valuable Learning Experience for Geography Undergraduates

ERIC Educational Resources Information Center

Mullens, Jo Beth

2016-01-01

Charging undergraduate geography students with the task of designing a recreational trail in their local community offers an engaging experiential opportunity with potential to advance geographic learning in a real-world setting. This article presents an assignment in which students were asked to develop a recreational trail proposal for an…

Peer Sharing Facilitates the Effect of Inquiry-Based Projects on Science Learning

ERIC Educational Resources Information Center

Chung, Hui-Min; Behan, Kristina Jackson

2010-01-01

Authentic assessment exercises are similar to real-world tasks that would be expected by a professional. An authentic assessment in combination with an inquiry-based learning activity enhances students' learning and rehearses them for their future roles, whether as scientists or as informed citizens. Over a period of 2 years, we experimented with…

Demountable connection for polymer optical fiber grating sensors

NASA Astrophysics Data System (ADS)

Abang, Ada; Webb, David J.

2012-08-01

The authors fabricated a demountable Ferrule connector/Physical contact connection between silica fiber and a polymer optical fiber (POF) containing a fiber Bragg grating. The use of a connector for POF grating sensors eliminates the limitations of ultraviolet glued connections and increases the ease with which the devices can be applied to real-world measurement tasks.

Creating an Alternate Reality: Critical, Creative, and Empathic Thinking Generated in the "Global Village Playground" Capstone Experience

ERIC Educational Resources Information Center

Dondlinger, Mary Jo; Wilson, Douglas A.

2012-01-01

The "Global Village Playground" ("GVP") was a capstone learning experience designed to address institutional assessment needs while providing an integrated and authentic learning experience for students aimed at fostering critical and creative thinking. In the "GVP", students work on simulated and real-world problems as a design team tasked with…

Mathematics for the Workplace. Applications from Medical Laboratory Technology. A Teacher's Guide.

ERIC Educational Resources Information Center

Wallace, Johnny M.; Jones, Dallas

This module presents a real-world context in which mathematics skills are used as part of a daily routine. The context is the medical laboratory technology field, and the module aims to help students develop the ability to use mathematics computations while performing tasks similar to those performed by a medical technologist. Materials in the…

Group Tasks, Activities, Dynamics, and Interactions in Collaborative Robotics Projects with Elementary and Middle School Children

ERIC Educational Resources Information Center

Yuen, Timothy T.; Boecking, Melanie; Stone, Jennifer; Tiger, Erin Price; Gomez, Alvaro; Guillen, Adrienne; Arreguin, Analisa

2014-01-01

Robotics provide the opportunity for students to bring their individual interests, perspectives and areas of expertise together in order to work collaboratively on real-world science, technology, engineering and mathematics (STEM) problems. This paper examines the nature of collaboration that manifests in groups of elementary and middle school…

Learning Logic in the Global Arena through Telecommunication.

ERIC Educational Resources Information Center

Lanham, Marion; Cowan, Marlene C.

The Information Age is a new cultural era in which the dominant resource is information. For educators attempting to prepare the increasingly diverse student body for the 1990's and beyond, the scope, magnitude, and constantly changing nature of this Information Age renders the task monumental. In an effort to create a real-world context for a…

Business Spanish in the Real World: A Task-Based Needs Analysis

ERIC Educational Resources Information Center

Martin, Alexandra; Adrada-Rafael, Sergio

2017-01-01

The growing demand for Spanish for Specific Purposes (SSP) courses at universities in the United States in the last two decades (Klee, 2015) has brought to light the need for more theoretically driven research in this field, which can inform pedagogical decisions and materials design. The present study conceptually replicates Serafini and Torres…

Designing Authentic Learning Activities to Train Pre-Service Teachers about Teaching Online

ERIC Educational Resources Information Center

Luo, Tian; Murray, Alexander; Crompton, Helen

2017-01-01

Online learning is increasingly being used in K-12 learning environments. A concomitant trend is found towards learning becoming "authentic" as students learn with tasks that are connected to real world occupations. In this study, 48 pre-service teachers use an online environment to engage in authentic practice as they developed online…

Teacher Immediacy and Decreased Student Quantitative Reasoning Anxiety: The Mediating Effect of Perception

ERIC Educational Resources Information Center

Kelly, Stephanie; Rice, Christopher; Wyatt, Bryce; Ducking, Johnny; Denton, Zachary

2015-01-01

There is global concern regarding the increased prevalence of math anxiety among college students, which is credited for a decrease in analytical degree completion rates and lower self-confidence among students in their ability to complete analytical tasks in the real world. The present study identified that, as expected, displays of instructional…

Integrating Role-Play with Case Study and Carbon Footprint Monitoring: A Transformative Approach to Enhancing Learners' Social Behavior for a More Sustainable Environment

ERIC Educational Resources Information Center

Oliver, Simon

2016-01-01

Learners were separated into groups representing the interests of parties that typically negotiate environmental affairs in real world scenarios (conservationists, scientists, politicians, NGOs, stakeholders), and tasked with preparing role-play simulations using a variety of flipped learning techniques. Learners' carbon footprints were monitored…

Teaching Business Statistics in a Computer Lab: Benefit or Distraction?

ERIC Educational Resources Information Center

Martin, Linda R.

2011-01-01

Teaching in a classroom configured with computers has been heralded as an aid to learning. Students receive the benefits of working with large data sets and real-world problems. However, with the advent of network and wireless connections, students can now use the computer for alternating tasks, such as emailing, web browsing, and social…

Maternal Socioeconomic Status Influences the Range of Expectations during Language Comprehension in Adulthood

ERIC Educational Resources Information Center

Troyer, Melissa; Borovsky, Arielle

2017-01-01

In infancy, maternal socioeconomic status (SES) is associated with real-time language processing skills, but whether or not (and if so, how) this relationship carries into adulthood is unknown. We explored the effects of maternal SES in college-aged adults on eye-tracked, spoken sentence comprehension tasks using the visual world paradigm. When…

The stress and workload of virtual reality training: the effects of presence, immersion and flow.

PubMed

Lackey, S J; Salcedo, J N; Szalma, J L; Hancock, P A

2016-08-01

The present investigation evaluated the effects of virtual reality (VR) training on the performance, perceived workload and stress response to a live training exercise in a sample of Soldiers. We also examined the relationship between the perceptions of that same VR as measured by engagement, immersion, presence, flow, perceived utility and ease of use with the performance, workload and stress reported on the live training task. To a degree, these latter relationships were moderated by task performance, as measured by binary (Go/No-Go) ratings. Participants who reported positive VR experiences also tended to experience lower stress and lower workload when performing the live version of the task. Thus, VR training regimens may be efficacious for mitigating the stress and workload associated with criterion tasks, thereby reducing the ultimate likelihood of real-world performance failure. Practitioner Summary: VR provides opportunities for training in artificial worlds comprised of highly realistic features. Our virtual room clearing scenario facilitated the integration of Training and Readiness objectives and satisfied training doctrine obligations in a compelling engaging experience for both novice and experienced trainees.

Brain activity during driving with distraction: an immersive fMRI study

PubMed Central

Schweizer, Tom A.; Kan, Karen; Hung, Yuwen; Tam, Fred; Naglie, Gary; Graham, Simon J.

2013-01-01

Introduction: Non-invasive measurements of brain activity have an important role to play in understanding driving ability. The current study aimed to identify the neural underpinnings of human driving behavior by visualizing the areas of the brain involved in driving under different levels of demand, such as driving while distracted or making left turns at busy intersections. Materials and Methods: To capture brain activity during driving, we placed a driving simulator with a fully functional steering wheel and pedals in a 3.0 Tesla functional magnetic resonance imaging (fMRI) system. To identify the brain areas involved while performing different real-world driving maneuvers, participants completed tasks ranging from simple (right turns) to more complex (left turns at busy intersections). To assess the effects of driving while distracted, participants were asked to perform an auditory task while driving analogous to speaking on a hands-free device and driving. Results: A widely distributed brain network was identified, especially when making left turns at busy intersections compared to more simple driving tasks. During distracted driving, brain activation shifted dramatically from the posterior, visual and spatial areas to the prefrontal cortex. Conclusions: Our findings suggest that the distracted brain sacrificed areas in the posterior brain important for visual attention and alertness to recruit enough brain resources to perform a secondary, cognitive task. The present findings offer important new insights into the scientific understanding of the neuro-cognitive mechanisms of driving behavior and lay down an important foundation for future clinical research. PMID:23450757

The relations between network-operation and topological-property in a scale-free and small-world network with community structure

NASA Astrophysics Data System (ADS)

Ma, Fei; Yao, Bing

2017-10-01

It is always an open, demanding and difficult task for generating available model to simulate dynamical functions and reveal inner principles from complex systems and networks. In this article, due to lots of real-life and artificial networks are built from series of simple and small groups (components), we discuss some interesting and helpful network-operation to generate more realistic network models. In view of community structure (modular topology), we present a class of sparse network models N(t , m) . At the moment, we capture the fact the N(t , 4) has not only scale-free feature, which means that the probability that a randomly selected vertex with degree k decays as a power-law, following P(k) ∼k-γ, where γ is the degree exponent, but also small-world property, which indicates that the typical distance between two uniform randomly chosen vertices grows proportionally to logarithm of the order of N(t , 4) , namely, relatively shorter diameter and lower average path length, simultaneously displays higher clustering coefficient. Next, as a new topological parameter correlating to reliability, synchronization capability and diffusion properties of networks, the number of spanning trees over a network is studied in more detail, an exact analytical solution for the number of spanning trees of the N(t , 4) is obtained. Based on the network-operation, part hub-vertex linking with each other will be helpful for structuring various network models and investigating the rules related with real-life networks.

Can Undergraduates Be Transdisciplinary? Promoting Transdisciplinary Engagement through Global Health Problem-Based Learning

ERIC Educational Resources Information Center

Hay, M. Cameron

2017-01-01

Undergraduate student learning focuses on the development of disciplinary strength in majors and minors so that students gain depth in particular fields, foster individual expertise, and learn problem solving from disciplinary perspectives. However, the complexities of real-world problems do not respect disciplinary boundaries. Complex problems…

Notes about COOL: Analysis and Highlights of Complex View in Education

ERIC Educational Resources Information Center

de Oliveira, C. A.

2012-01-01

Purpose: The purpose of this paper is to present principles from the complex approach in education and describe some practical pedagogic experiences enhancing how "real world" perspectives have influenced and contributed to curriculum development. Design/methodology/approach: Necessity of integration in terms of knowledge modeling is an…

Introductory Earth science education by near real time animated visualization of seismic wave propagation across Transportable Array of USArray

NASA Astrophysics Data System (ADS)

Attanayake, J.; Ghosh, A.; Amosu, A.

2010-12-01

Students of this generation are markedly different from their predecessors because they grow up and learn in a world of visual technology populated by touch screens and smart boards. Recent studies have found that the attention span of university students whose medium of instruction is traditional teaching methods is roughly fifteen minutes and that there is a significant drop in the number of students paying attention over time in a lecture. On the other hand, when carefully segmented and learner-paced, animated visualizations can enhance the learning experience. Therefore, the instructors are faced with the difficult task of designing more complex teaching environments to improve learner productivity. We have developed an animated visualization of earthquake wave propagation across a generic transect of the Transportable Array of the USArray from a magnitude 6.9 event that occurred in the Gulf of California on August 3rd 2009. Despite the fact that the proto-type tool is built in MATLAB - one of the most popular programming environments among the seismology community, the movies can be run as a standalone stream with any built-in media player that supports .avi file format. We infer continuous ground motion along the transect through a projection and interpolation mechanism based on data from stations within 100 km of the transect. In the movies we identify the arrival of surface waves that have high amplitudes. However, over time, although typical Rayleigh type ground motion can be observed, the motion at any given point becomes complex owing to interference of different wave types and different seismic properties of the subsurface. This clearly is different from simple representations of seismic wave propagation in most introductory textbooks. Further, we find a noisy station that shows unusually high amplitude. We refrain from deleting this station in order to demonstrate that in a real world experiment, generally, there will be complexities arising from unexpected behavior of instruments and/or the system under investigation. Explaining such behavior and exploring ways to minimize biases arising from it is an important lesson to learn in introductory science classes. This program can generate visualizations of ground motion from events in the Gulf of California in near real time and with little further development, from events elsewhere.

A system for extracting 3-dimensional measurements from a stereo pair of TV cameras

NASA Technical Reports Server (NTRS)

Yakimovsky, Y.; Cunningham, R.

1976-01-01

Obtaining accurate three-dimensional (3-D) measurement from a stereo pair of TV cameras is a task requiring camera modeling, calibration, and the matching of the two images of a real 3-D point on the two TV pictures. A system which models and calibrates the cameras and pairs the two images of a real-world point in the two pictures, either manually or automatically, was implemented. This system is operating and provides three-dimensional measurements resolution of + or - mm at distances of about 2 m.

Age Patterns in Risk Taking Across the World.

PubMed

Duell, Natasha; Steinberg, Laurence; Icenogle, Grace; Chein, Jason; Chaudhary, Nandita; Di Giunta, Laura; Dodge, Kenneth A; Fanti, Kostas A; Lansford, Jennifer E; Oburu, Paul; Pastorelli, Concetta; Skinner, Ann T; Sorbring, Emma; Tapanya, Sombat; Uribe Tirado, Liliana Maria; Alampay, Liane Peña; Al-Hassan, Suha M; Takash, Hanan M S; Bacchini, Dario; Chang, Lei

2018-05-01

Epidemiological data indicate that risk behaviors are among the leading causes of adolescent morbidity and mortality worldwide. Consistent with this, laboratory-based studies of age differences in risk behavior allude to a peak in adolescence, suggesting that adolescents demonstrate a heightened propensity, or inherent inclination, to take risks. Unlike epidemiological reports, studies of risk taking propensity have been limited to Western samples, leaving questions about the extent to which heightened risk taking propensity is an inherent or culturally constructed aspect of adolescence. In the present study, age patterns in risk-taking propensity (using two laboratory tasks: the Stoplight and the BART) and real-world risk taking (using self-reports of health and antisocial risk taking) were examined in a sample of 5227 individuals (50.7% female) ages 10-30 (M = 17.05 years, SD = 5.91) from 11 Western and non-Western countries (China, Colombia, Cyprus, India, Italy, Jordan, Kenya, the Philippines, Sweden, Thailand, and the US). Two hypotheses were tested: (1) risk taking follows an inverted-U pattern across age groups, peaking earlier on measures of risk taking propensity than on measures of real-world risk taking, and (2) age patterns in risk taking propensity are more consistent across countries than age patterns in real-world risk taking. Overall, risk taking followed the hypothesized inverted-U pattern across age groups, with health risk taking evincing the latest peak. Age patterns in risk taking propensity were more consistent across countries than age patterns in real-world risk taking. Results suggest that although the association between age and risk taking is sensitive to measurement and culture, around the world, risk taking is generally highest among late adolescents.

Estimation of detection thresholds for redirected walking techniques.

PubMed

Steinicke, Frank; Bruder, Gerd; Jerald, Jason; Frenz, Harald; Lappe, Markus

2010-01-01

In immersive virtual environments (IVEs), users can control their virtual viewpoint by moving their tracked head and walking through the real world. Usually, movements in the real world are mapped one-to-one to virtual camera motions. With redirection techniques, the virtual camera is manipulated by applying gains to user motion so that the virtual world moves differently than the real world. Thus, users can walk through large-scale IVEs while physically remaining in a reasonably small workspace. In psychophysical experiments with a two-alternative forced-choice task, we have quantified how much humans can unknowingly be redirected on physical paths that are different from the visually perceived paths. We tested 12 subjects in three different experiments: (E1) discrimination between virtual and physical rotations, (E2) discrimination between virtual and physical straightforward movements, and (E3) discrimination of path curvature. In experiment E1, subjects performed rotations with different gains, and then had to choose whether the visually perceived rotation was smaller or greater than the physical rotation. In experiment E2, subjects chose whether the physical walk was shorter or longer than the visually perceived scaled travel distance. In experiment E3, subjects estimate the path curvature when walking a curved path in the real world while the visual display shows a straight path in the virtual world. Our results show that users can be turned physically about 49 percent more or 20 percent less than the perceived virtual rotation, distances can be downscaled by 14 percent and upscaled by 26 percent, and users can be redirected on a circular arc with a radius greater than 22 m while they believe that they are walking straight.

Exploring the effects of driving experience on hazard awareness and risk perception via real-time hazard identification, hazard classification, and rating tasks.

PubMed

Borowsky, Avinoam; Oron-Gilad, Tal

2013-10-01

This study investigated the effects of driving experience on hazard awareness and risk perception skills. These topics have previously been investigated separately, yet a novel approach is suggested where hazard awareness and risk perception are examined concurrently. Young, newly qualified drivers, experienced drivers, and a group of commercial drivers, namely, taxi drivers performed three consecutive tasks: (1) observed 10 short movies of real-world driving situations and were asked to press a button each time they identified a hazardous situation; (2) observed one of three possible sub-sets of 8 movies (out of the 10 they have seen earlier) for the second time, and were asked to categorize them into an arbitrary number of clusters according to the similarity in their hazardous situation; and (3) observed the same sub-set for a third time and following each movie were asked to rate its level of hazardousness. The first task is considered a real-time identification task while the other two are performed using hindsight. During it participants' eye movements were recorded. Results showed that taxi drivers were more sensitive to hidden hazards than the other driver groups and that young-novices were the least sensitive. Young-novice drivers also relied heavily on materialized hazards in their categorization structure. In addition, it emerged that risk perception was derived from two major components: the likelihood of a crash and the severity of its outcome. Yet, the outcome was rarely considered under time pressure (i.e., in real-time hazard identification tasks). Using hindsight, when drivers were provided with the opportunity to rate the movies' hazardousness more freely (rating task) they considered both components. Otherwise, in the categorization task, they usually chose the severity of the crash outcome as their dominant criterion. Theoretical and practical implications are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Knowledge-Based Reinforcement Learning for Data Mining

NASA Astrophysics Data System (ADS)

Kudenko, Daniel; Grzes, Marek

Data Mining is the process of extracting patterns from data. Two general avenues of research in the intersecting areas of agents and data mining can be distinguished. The first approach is concerned with mining an agent’s observation data in order to extract patterns, categorize environment states, and/or make predictions of future states. In this setting, data is normally available as a batch, and the agent’s actions and goals are often independent of the data mining task. The data collection is mainly considered as a side effect of the agent’s activities. Machine learning techniques applied in such situations fall into the class of supervised learning. In contrast, the second scenario occurs where an agent is actively performing the data mining, and is responsible for the data collection itself. For example, a mobile network agent is acquiring and processing data (where the acquisition may incur a certain cost), or a mobile sensor agent is moving in a (perhaps hostile) environment, collecting and processing sensor readings. In these settings, the tasks of the agent and the data mining are highly intertwined and interdependent (or even identical). Supervised learning is not a suitable technique for these cases. Reinforcement Learning (RL) enables an agent to learn from experience (in form of reward and punishment for explorative actions) and adapt to new situations, without a teacher. RL is an ideal learning technique for these data mining scenarios, because it fits the agent paradigm of continuous sensing and acting, and the RL agent is able to learn to make decisions on the sampling of the environment which provides the data. Nevertheless, RL still suffers from scalability problems, which have prevented its successful use in many complex real-world domains. The more complex the tasks, the longer it takes a reinforcement learning algorithm to converge to a good solution. For many real-world tasks, human expert knowledge is available. For example, human experts have developed heuristics that help them in planning and scheduling resources in their work place. However, this domain knowledge is often rough and incomplete. When the domain knowledge is used directly by an automated expert system, the solutions are often sub-optimal, due to the incompleteness of the knowledge, the uncertainty of environments, and the possibility to encounter unexpected situations. RL, on the other hand, can overcome the weaknesses of the heuristic domain knowledge and produce optimal solutions. In the talk we propose two techniques, which represent first steps in the area of knowledge-based RL (KBRL). The first technique [1] uses high-level STRIPS operator knowledge in reward shaping to focus the search for the optimal policy. Empirical results show that the plan-based reward shaping approach outperforms other RL techniques, including alternative manual and MDP-based reward shaping when it is used in its basic form. We showed that MDP-based reward shaping may fail and successful experiments with STRIPS-based shaping suggest modifications which can overcome encountered problems. The STRIPSbased method we propose allows expressing the same domain knowledge in a different way and the domain expert can choose whether to define an MDP or STRIPS planning task. We also evaluated the robustness of the proposed STRIPS-based technique to errors in the plan knowledge. In case that STRIPS knowledge is not available, we propose a second technique [2] that shapes the reward with hierarchical tile coding. Where the Q-function is represented with low-level tile coding, a V-function with coarser tile coding can be learned in parallel and used to approximate the potential for ground states. In the context of data mining, our KBRL approaches can also be used for any data collection task where the acquisition of data may incur considerable cost. In addition, observing the data collection agent in specific scenarios may lead to new insights into optimal data collection behaviour in the respective domains. In future work, we intend to demonstrate and evaluate our techniques on concrete real-world data mining applications.

Comparative analysis of two discretizations of Ricci curvature for complex networks.

PubMed

Samal, Areejit; Sreejith, R P; Gu, Jiao; Liu, Shiping; Saucan, Emil; Jost, Jürgen

2018-06-05

We have performed an empirical comparison of two distinct notions of discrete Ricci curvature for graphs or networks, namely, the Forman-Ricci curvature and Ollivier-Ricci curvature. Importantly, these two discretizations of the Ricci curvature were developed based on different properties of the classical smooth notion, and thus, the two notions shed light on different aspects of network structure and behavior. Nevertheless, our extensive computational analysis in a wide range of both model and real-world networks shows that the two discretizations of Ricci curvature are highly correlated in many networks. Moreover, we show that if one considers the augmented Forman-Ricci curvature which also accounts for the two-dimensional simplicial complexes arising in graphs, the observed correlation between the two discretizations is even higher, especially, in real networks. Besides the potential theoretical implications of these observations, the close relationship between the two discretizations has practical implications whereby Forman-Ricci curvature can be employed in place of Ollivier-Ricci curvature for faster computation in larger real-world networks whenever coarse analysis suffices.

Effective algorithm for solving complex problems of production control and of material flows control of industrial enterprise

NASA Astrophysics Data System (ADS)

Mezentsev, Yu A.; Baranova, N. V.

2018-05-01

A universal economical and mathematical model designed for determination of optimal strategies for managing subsystems (components of subsystems) of production and logistics of enterprises is considered. Declared universality allows taking into account on the system level both production components, including limitations on the ways of converting raw materials and components into sold goods, as well as resource and logical restrictions on input and output material flows. The presented model and generated control problems are developed within the framework of the unified approach that allows one to implement logical conditions of any complexity and to define corresponding formal optimization tasks. Conceptual meaning of used criteria and limitations are explained. The belonging of the generated tasks of the mixed programming with the class of NP is shown. An approximate polynomial algorithm for solving the posed optimization tasks for mixed programming of real dimension with high computational complexity is proposed. Results of testing the algorithm on the tasks in a wide range of dimensions are presented.

The Relationship between Observed Task Characteristics and the Pattern of Seventh Grade Students' Situational Engagement during a Science Unit

NASA Astrophysics Data System (ADS)

Glassman, Sarah J.

Student engagement is an important aspect of teaching and learning. Traditionally, engagement has been measured as a static trait. This study measured engagement as a fluid trait in order to explore the relationship between seventh grade students' situational engagement over a science unit and five specific task characteristics. Further, this study investigated how the changing pattern of instruction is related to a changing pattern of student engagement. Informed by Self-Determination Theory, the five specific task characteristics investigated were: the use of tasks that give students opportunities to act autonomously (choice), the use of tasks that challenge students (challenge), constructive feedback from the teacher or peers that guides students work on the current task (feedback), the inclusion of tasks that require student collaboration (collaboration), and tasks in which the importance or relevance is explained to students or the task includes a real-world problem or scenario (real-life significance). Student engagement was measured as a multidimensional trait consisting of behavioral, emotional, and cognitive dimensions. Participants included two teachers and 37 students. Two classrooms were observed and video-recorded for 10 consecutive 1.5 hour blocks during a unit investigating cells. At the end of each block students completed a three item survey for each task. For all tasks in both classrooms, the cumulative presence of task characteristics correlated with student engagement. However, students' behavioral engagement negatively correlated with the use of choice. Students' engagement increased from low to high during four related tasks exhibiting the highest cumulative presence of task characteristics. Nine out of 10 tasks with the highest student engagement involved hands-on learning. However, students' engagement was lower during tasks elaborating on those hands-on tasks.

Evaluation of 2 cognitive abilities tests in a dual-task environment

NASA Technical Reports Server (NTRS)

Vidulich, M. A.; Tsang, P. S.

1986-01-01

Most real world operators are required to perform multiple tasks simultaneously. In some cases, such as flying a high performance aircraft or trouble shooting a failing nuclear power plant, the operator's ability to time share or process in parallel" can be driven to extremes. This has created interest in selection tests of cognitive abilities. Two tests that have been suggested are the Dichotic Listening Task and the Cognitive Failures Questionnaire. Correlations between these test results and time sharing performance were obtained and the validity of these tests were examined. The primary task was a tracking task with dynamically varying bandwidth. This was performed either alone or concurrently with either another tracking task or a spatial transformation task. The results were: (1) An unexpected negative correlation was detected between the two tests; (2) The lack of correlation between either test and task performance made the predictive utility of the tests scores appear questionable; (3) Pilots made more errors on the Dichotic Listening Task than college students.

Measuring Mindreading: A Review of Behavioral Approaches to Testing Cognitive and Affective Mental State Attribution in Neurologically Typical Adults.

PubMed

Turner, Rose; Felisberti, Fatima M

2017-01-01

Mindreading refers to the ability to attribute mental states, including thoughts, intentions and emotions, to oneself and others, and is essential for navigating the social world. Empirical mindreading research has predominantly featured children, groups with autism spectrum disorder and clinical samples, and many standard tasks suffer ceiling effects with neurologically typical (NT) adults. We first outline a case for studying mindreading in NT adults and proceed to review tests of emotion perception, cognitive and affective mentalizing, and multidimensional tasks combining these facets. We focus on selected examples of core experimental paradigms including emotion recognition tests, social vignettes, narrative fiction (prose and film) and participative interaction (in real and virtual worlds), highlighting challenges for studies with NT adult cohorts. We conclude that naturalistic, multidimensional approaches may be productively applied alongside traditional tasks to facilitate a more nuanced picture of mindreading in adulthood, and to ensure construct validity whilst remaining sensitive to variation at the upper echelons of the ability.

Measuring Mindreading: A Review of Behavioral Approaches to Testing Cognitive and Affective Mental State Attribution in Neurologically Typical Adults

PubMed Central

Turner, Rose; Felisberti, Fatima M.

2017-01-01

Mindreading refers to the ability to attribute mental states, including thoughts, intentions and emotions, to oneself and others, and is essential for navigating the social world. Empirical mindreading research has predominantly featured children, groups with autism spectrum disorder and clinical samples, and many standard tasks suffer ceiling effects with neurologically typical (NT) adults. We first outline a case for studying mindreading in NT adults and proceed to review tests of emotion perception, cognitive and affective mentalizing, and multidimensional tasks combining these facets. We focus on selected examples of core experimental paradigms including emotion recognition tests, social vignettes, narrative fiction (prose and film) and participative interaction (in real and virtual worlds), highlighting challenges for studies with NT adult cohorts. We conclude that naturalistic, multidimensional approaches may be productively applied alongside traditional tasks to facilitate a more nuanced picture of mindreading in adulthood, and to ensure construct validity whilst remaining sensitive to variation at the upper echelons of the ability. PMID:28174552

The impact of task demand on visual word recognition.

PubMed

Yang, J; Zevin, J

2014-07-11

The left occipitotemporal cortex has been found sensitive to the hierarchy of increasingly complex features in visually presented words, from individual letters to bigrams and morphemes. However, whether this sensitivity is a stable property of the brain regions engaged by word recognition is still unclear. To address the issue, the current study investigated whether different task demands modify this sensitivity. Participants viewed real English words and stimuli with hierarchical word-likeness while performing a lexical decision task (i.e., to decide whether each presented stimulus is a real word) and a symbol detection task. General linear model and independent component analysis indicated strong activation in the fronto-parietal and temporal regions during the two tasks. Furthermore, the bilateral inferior frontal gyrus and insula showed significant interaction effects between task demand and stimulus type in the pseudoword condition. The occipitotemporal cortex showed strong main effects for task demand and stimulus type, but no sensitivity to the hierarchical word-likeness was found. These results suggest that different task demands on semantic, phonological and orthographic processes can influence the involvement of the relevant regions during visual word recognition. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Biologically plausible learning in recurrent neural networks reproduces neural dynamics observed during cognitive tasks

PubMed Central

Miconi, Thomas

2017-01-01

Neural activity during cognitive tasks exhibits complex dynamics that flexibly encode task-relevant variables. Chaotic recurrent networks, which spontaneously generate rich dynamics, have been proposed as a model of cortical computation during cognitive tasks. However, existing methods for training these networks are either biologically implausible, and/or require a continuous, real-time error signal to guide learning. Here we show that a biologically plausible learning rule can train such recurrent networks, guided solely by delayed, phasic rewards at the end of each trial. Networks endowed with this learning rule can successfully learn nontrivial tasks requiring flexible (context-dependent) associations, memory maintenance, nonlinear mixed selectivities, and coordination among multiple outputs. The resulting networks replicate complex dynamics previously observed in animal cortex, such as dynamic encoding of task features and selective integration of sensory inputs. We conclude that recurrent neural networks offer a plausible model of cortical dynamics during both learning and performance of flexible behavior. DOI: http://dx.doi.org/10.7554/eLife.20899.001 PMID:28230528

Biologically plausible learning in recurrent neural networks reproduces neural dynamics observed during cognitive tasks.

PubMed

Miconi, Thomas

2017-02-23

Neural activity during cognitive tasks exhibits complex dynamics that flexibly encode task-relevant variables. Chaotic recurrent networks, which spontaneously generate rich dynamics, have been proposed as a model of cortical computation during cognitive tasks. However, existing methods for training these networks are either biologically implausible, and/or require a continuous, real-time error signal to guide learning. Here we show that a biologically plausible learning rule can train such recurrent networks, guided solely by delayed, phasic rewards at the end of each trial. Networks endowed with this learning rule can successfully learn nontrivial tasks requiring flexible (context-dependent) associations, memory maintenance, nonlinear mixed selectivities, and coordination among multiple outputs. The resulting networks replicate complex dynamics previously observed in animal cortex, such as dynamic encoding of task features and selective integration of sensory inputs. We conclude that recurrent neural networks offer a plausible model of cortical dynamics during both learning and performance of flexible behavior.

An ant colony optimization based algorithm for identifying gene regulatory elements.

PubMed

Liu, Wei; Chen, Hanwu; Chen, Ling

2013-08-01

It is one of the most important tasks in bioinformatics to identify the regulatory elements in gene sequences. Most of the existing algorithms for identifying regulatory elements are inclined to converge into a local optimum, and have high time complexity. Ant Colony Optimization (ACO) is a meta-heuristic method based on swarm intelligence and is derived from a model inspired by the collective foraging behavior of real ants. Taking advantage of the ACO in traits such as self-organization and robustness, this paper designs and implements an ACO based algorithm named ACRI (ant-colony-regulatory-identification) for identifying all possible binding sites of transcription factor from the upstream of co-expressed genes. To accelerate the ants' searching process, a strategy of local optimization is presented to adjust the ants' start positions on the searched sequences. By exploiting the powerful optimization ability of ACO, the algorithm ACRI can not only improve precision of the results, but also achieve a very high speed. Experimental results on real world datasets show that ACRI can outperform other traditional algorithms in the respects of speed and quality of solutions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fused Reality for Enhanced Flight Test Capabilities

NASA Technical Reports Server (NTRS)

Bachelder, Ed; Klyde, David

2011-01-01

The feasibility of using Fused Reality-based simulation technology to enhance flight test capabilities has been investigated. In terms of relevancy to piloted evaluation, there remains no substitute for actual flight tests, even when considering the fidelity and effectiveness of modern ground-based simulators. In addition to real-world cueing (vestibular, visual, aural, environmental, etc.), flight tests provide subtle but key intangibles that cannot be duplicated in a ground-based simulator. There is, however, a cost to be paid for the benefits of flight in terms of budget, mission complexity, and safety, including the need for ground and control-room personnel, additional aircraft, etc. A Fused Reality(tm) (FR) Flight system was developed that allows a virtual environment to be integrated with the test aircraft so that tasks such as aerial refueling, formation flying, or approach and landing can be accomplished without additional aircraft resources or the risk of operating in close proximity to the ground or other aircraft. Furthermore, the dynamic motions of the simulated objects can be directly correlated with the responses of the test aircraft. The FR Flight system will allow real-time observation of, and manual interaction with, the cockpit environment that serves as a frame for the virtual out-the-window scene.

MHODE: a local-homogeneity theory for improved source-parameter estimation of potential fields

NASA Astrophysics Data System (ADS)

Fedi, Maurizio; Florio, Giovanni; Paoletti, Valeria

2015-08-01

We describe a multihomogeneity theory for source-parameter estimation of potential fields. Similar to what happens for random source models, where the monofractal scaling-law has been generalized into a multifractal law, we propose to generalize the homogeneity law into a multihomogeneity law. This allows a theoretically correct approach to study real-world potential fields, which are inhomogeneous and so do not show scale invariance, except in the asymptotic regions (very near to or very far from their sources). Since the scaling properties of inhomogeneous fields change with the scale of observation, we show that they may be better studied at a set of scales than at a single scale and that a multihomogeneous model is needed to explain its complex scaling behaviour. In order to perform this task, we first introduce fractional-degree homogeneous fields, to show that: (i) homogeneous potential fields may have fractional or integer degree; (ii) the source-distributions for a fractional-degree are not confined in a bounded region, similarly to some integer-degree models, such as the infinite line mass and (iii) differently from the integer-degree case, the fractional-degree source distributions are no longer uniform density functions. Using this enlarged set of homogeneous fields, real-world anomaly fields are studied at different scales, by a simple search, at any local window W, for the best homogeneous field of either integer or fractional-degree, this yielding a multiscale set of local homogeneity-degrees and depth estimations which we call multihomogeneous model. It is so defined a new technique of source parameter estimation (Multi-HOmogeneity Depth Estimation, MHODE), permitting retrieval of the source parameters of complex sources. We test the method with inhomogeneous fields of finite sources, such as faults or cylinders, and show its effectiveness also in a real-case example. These applications show the usefulness of the new concepts, multihomogeneity and fractional homogeneity-degree, to obtain valid estimates of the source parameters in a consistent theoretical framework, so overcoming the limitations imposed by global-homogeneity to widespread methods, such as Euler deconvolution.

Ubiquitousness of link-density and link-pattern communities in real-world networks

NASA Astrophysics Data System (ADS)

Šubelj, L.; Bajec, M.

2012-01-01

Community structure appears to be an intrinsic property of many complex real-world networks. However, recent work shows that real-world networks reveal even more sophisticated modules than classical cohesive (link-density) communities. In particular, networks can also be naturally partitioned according to similar patterns of connectedness among the nodes, revealing link-pattern communities. We here propose a propagation based algorithm that can extract both link-density and link-pattern communities, without any prior knowledge of the true structure. The algorithm was first validated on different classes of synthetic benchmark networks with community structure, and also on random networks. We have further applied the algorithm to different social, information, technological and biological networks, where it indeed reveals meaningful (composites of) link-density and link-pattern communities. The results thus seem to imply that, similarly as link-density counterparts, link-pattern communities appear ubiquitous in nature and design.

Modelling the human immunodeficiency virus (HIV) epidemic: A review of the substance and role of models in South Africa

PubMed Central

2018-01-01

We review key mathematical models of the South African human immunodeficiency virus (HIV) epidemic from the early 1990s onwards. In our descriptions, we sometimes differentiate between the concepts of a model world and its mathematical or computational implementation. The model world is the conceptual realm in which we explicitly declare the rules – usually some simplification of ‘real world’ processes as we understand them. Computing details of informative scenarios in these model worlds is a task requiring specialist knowledge, but all other aspects of the modelling process, from describing the model world to identifying the scenarios and interpreting model outputs, should be understandable to anyone with an interest in the epidemic. PMID:29568647

The Social Process of Analyzing Real Water Resource Systems Plans and Management Policies

NASA Astrophysics Data System (ADS)

Loucks, Daniel

2016-04-01

Developing and applying systems analysis methods for improving the development and management of real world water resource systems, I have learned, is primarily a social process. This talk is a call for more recognition of this reality in the modeling approaches we propose in the papers and books we publish. The mathematical models designed to inform planners and managers of water systems that we see in many of our journals often seem more complex than they need be. They also often seem not as connected to reality as they could be. While it may be easier to publish descriptions of complex models than simpler ones, and while adding complexity to models might make them better able to mimic or resemble the actual complexity of the real physical and/or social systems or processes being analyzed, the usefulness of such models often can be an illusion. Sometimes the important features of reality that are of concern or interest to those who make decisions can be adequately captured using relatively simple models. Finding the right balance for the particular issues being addressed or the particular decisions that need to be made is an art. When applied to real world problems or issues in specific basins or regions, systems modeling projects often involve more attention to the social aspects than the mathematical ones. Mathematical models addressing connected interacting interdependent components of complex water systems are in fact some of the most useful methods we have to study and better understand the systems we manage around us. They can help us identify and evaluate possible alternative solutions to problems facing humanity today. The study of real world systems of interacting components using mathematical models is commonly called applied systems analyses. Performing such analyses with decision makers rather than of decision makers is critical if the needed trust between project personnel and their clients is to be developed. Using examples from recent and ongoing modeling projects in different parts of the world, this talk will attempt to show the dependency on the degree of project success with the degree of attention given to the communication between project personnel, the stakeholders and decision making institutions. It will also highlight how initial project terms-of-reference and expected outcomes can change, sometimes in surprising ways, during the course of such projects. Changing project objectives often result from changing stakeholder values, emphasizing the need for analyses that can adapt to this uncertainty.

Leveraging Large-Scale Semantic Networks for Adaptive Robot Task Learning and Execution.

PubMed

Boteanu, Adrian; St Clair, Aaron; Mohseni-Kabir, Anahita; Saldanha, Carl; Chernova, Sonia

2016-12-01

This work seeks to leverage semantic networks containing millions of entries encoding assertions of commonsense knowledge to enable improvements in robot task execution and learning. The specific application we explore in this project is object substitution in the context of task adaptation. Humans easily adapt their plans to compensate for missing items in day-to-day tasks, substituting a wrap for bread when making a sandwich, or stirring pasta with a fork when out of spoons. Robot plan execution, however, is far less robust, with missing objects typically leading to failure if the robot is not aware of alternatives. In this article, we contribute a context-aware algorithm that leverages the linguistic information embedded in the task description to identify candidate substitution objects without reliance on explicit object affordance information. Specifically, we show that the task context provided by the task labels within the action structure of a task plan can be leveraged to disambiguate information within a noisy large-scale semantic network containing hundreds of potential object candidates to identify successful object substitutions with high accuracy. We present two extensive evaluations of our work on both abstract and real-world robot tasks, showing that the substitutions made by our system are valid, accepted by users, and lead to a statistically significant reduction in robot learning time. In addition, we report the outcomes of testing our approach with a large number of crowd workers interacting with a robot in real time.

Machine Learning Based Online Performance Prediction for Runtime Parallelization and Task Scheduling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, J; Ma, X; Singh, K

2008-10-09

With the emerging many-core paradigm, parallel programming must extend beyond its traditional realm of scientific applications. Converting existing sequential applications as well as developing next-generation software requires assistance from hardware, compilers and runtime systems to exploit parallelism transparently within applications. These systems must decompose applications into tasks that can be executed in parallel and then schedule those tasks to minimize load imbalance. However, many systems lack a priori knowledge about the execution time of all tasks to perform effective load balancing with low scheduling overhead. In this paper, we approach this fundamental problem using machine learning techniques first to generatemore » performance models for all tasks and then applying those models to perform automatic performance prediction across program executions. We also extend an existing scheduling algorithm to use generated task cost estimates for online task partitioning and scheduling. We implement the above techniques in the pR framework, which transparently parallelizes scripts in the popular R language, and evaluate their performance and overhead with both a real-world application and a large number of synthetic representative test scripts. Our experimental results show that our proposed approach significantly improves task partitioning and scheduling, with maximum improvements of 21.8%, 40.3% and 22.1% and average improvements of 15.9%, 16.9% and 4.2% for LMM (a real R application) and synthetic test cases with independent and dependent tasks, respectively.« less

Overview of the gene ontology task at BioCreative IV.

PubMed

Mao, Yuqing; Van Auken, Kimberly; Li, Donghui; Arighi, Cecilia N; McQuilton, Peter; Hayman, G Thomas; Tweedie, Susan; Schaeffer, Mary L; Laulederkind, Stanley J F; Wang, Shur-Jen; Gobeill, Julien; Ruch, Patrick; Luu, Anh Tuan; Kim, Jung-Jae; Chiang, Jung-Hsien; Chen, Yu-De; Yang, Chia-Jung; Liu, Hongfang; Zhu, Dongqing; Li, Yanpeng; Yu, Hong; Emadzadeh, Ehsan; Gonzalez, Graciela; Chen, Jian-Ming; Dai, Hong-Jie; Lu, Zhiyong

2014-01-01

Gene ontology (GO) annotation is a common task among model organism databases (MODs) for capturing gene function data from journal articles. It is a time-consuming and labor-intensive task, and is thus often considered as one of the bottlenecks in literature curation. There is a growing need for semiautomated or fully automated GO curation techniques that will help database curators to rapidly and accurately identify gene function information in full-length articles. Despite multiple attempts in the past, few studies have proven to be useful with regard to assisting real-world GO curation. The shortage of sentence-level training data and opportunities for interaction between text-mining developers and GO curators has limited the advances in algorithm development and corresponding use in practical circumstances. To this end, we organized a text-mining challenge task for literature-based GO annotation in BioCreative IV. More specifically, we developed two subtasks: (i) to automatically locate text passages that contain GO-relevant information (a text retrieval task) and (ii) to automatically identify relevant GO terms for the genes in a given article (a concept-recognition task). With the support from five MODs, we provided teams with >4000 unique text passages that served as the basis for each GO annotation in our task data. Such evidence text information has long been recognized as critical for text-mining algorithm development but was never made available because of the high cost of curation. In total, seven teams participated in the challenge task. From the team results, we conclude that the state of the art in automatically mining GO terms from literature has improved over the past decade while much progress is still needed for computer-assisted GO curation. Future work should focus on addressing remaining technical challenges for improved performance of automatic GO concept recognition and incorporating practical benefits of text-mining tools into real-world GO annotation. http://www.biocreative.org/tasks/biocreative-iv/track-4-GO/. Published by Oxford University Press 2014. This work is written by US Government employees and is in the public domain in the US.

Neural correlates of naturalistic social cognition: brain-behavior relationships in healthy adults.

PubMed

Deuse, L; Rademacher, L M; Winkler, L; Schultz, R T; Gründer, G; Lammertz, S E

2016-11-01

Being able to infer the thoughts, feelings and intentions of those around us is indispensable in order to function in a social world. Despite growing interest in social cognition and its neural underpinnings, the factors that contribute to successful mental state attribution remain unclear. Current knowledge is limited because the most widely used tasks suffer from two main constraints: (i) They fail to capture individual variability due to ceiling effects and (ii) they use highly simplistic, often artificial stimuli inapt to mirror real-world socio-cognitive demands. In the present study, we address these problems by employing complex depictions of naturalistic social interactions that vary in both valence (positive vs negative) and ambiguity (high vs low). Thirty-eight healthy participants (20 female) made mental state judgments while brain responses were obtained using functional magnetic resonance imaging (fMRI). Accuracy varied based on valence and ambiguity conditions and women were more accurate than men with highly ambiguous social stimuli. Activity of the orbitofrontal cortex predicted performance in the high ambiguity condition. The results shed light on subtle differences in mentalizing abilities and associated neural activity. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Clutter in electronic medical records: examining its performance and attentional costs using eye tracking.

PubMed

Moacdieh, Nadine; Sarter, Nadine

2015-06-01

The objective was to use eye tracking to trace the underlying changes in attention allocation associated with the performance effects of clutter, stress, and task difficulty in visual search and noticing tasks. Clutter can degrade performance in complex domains, yet more needs to be known about the associated changes in attention allocation, particularly in the presence of stress and for different tasks. Frequently used and relatively simple eye tracking metrics do not effectively capture the various effects of clutter, which is critical for comprehensively analyzing clutter and developing targeted, real-time countermeasures. Electronic medical records (EMRs) were chosen as the application domain for this research. Clutter, stress, and task difficulty were manipulated, and physicians' performance on search and noticing tasks was recorded. Several eye tracking metrics were used to trace attention allocation throughout those tasks, and subjective data were gathered via a debriefing questionnaire. Clutter degraded performance in terms of response time and noticing accuracy. These decrements were largely accentuated by high stress and task difficulty. Eye tracking revealed the underlying attentional mechanisms, and several display-independent metrics were shown to be significant indicators of the effects of clutter. Eye tracking provides a promising means to understand in detail (offline) and prevent (in real time) major performance breakdowns due to clutter. Display designers need to be aware of the risks of clutter in EMRs and other complex displays and can use the identified eye tracking metrics to evaluate and/or adjust their display. © 2015, Human Factors and Ergonomics Society.

A Comparison of Techniques for Camera Selection and Hand-Off in a Video Network

NASA Astrophysics Data System (ADS)

Li, Yiming; Bhanu, Bir

Video networks are becoming increasingly important for solving many real-world problems. Multiple video sensors require collaboration when performing various tasks. One of the most basic tasks is the tracking of objects, which requires mechanisms to select a camera for a certain object and hand-off this object from one camera to another so as to accomplish seamless tracking. In this chapter, we provide a comprehensive comparison of current and emerging camera selection and hand-off techniques. We consider geometry-, statistics-, and game theory-based approaches and provide both theoretical and experimental comparison using centralized and distributed computational models. We provide simulation and experimental results using real data for various scenarios of a large number of cameras and objects for in-depth understanding of strengths and weaknesses of these techniques.

HyperForest: A high performance multi-processor architecture for real-time intelligent systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia, P. Jr.; Rebeil, J.P.; Pollard, H.

1997-04-01

Intelligent Systems are characterized by the intensive use of computer power. The computer revolution of the last few years is what has made possible the development of the first generation of Intelligent Systems. Software for second generation Intelligent Systems will be more complex and will require more powerful computing engines in order to meet real-time constraints imposed by new robots, sensors, and applications. A multiprocessor architecture was developed that merges the advantages of message-passing and shared-memory structures: expendability and real-time compliance. The HyperForest architecture will provide an expandable real-time computing platform for computationally intensive Intelligent Systems and open the doorsmore » for the application of these systems to more complex tasks in environmental restoration and cleanup projects, flexible manufacturing systems, and DOE`s own production and disassembly activities.« less

Community detection in complex networks by using membrane algorithm

NASA Astrophysics Data System (ADS)

Liu, Chuang; Fan, Linan; Liu, Zhou; Dai, Xiang; Xu, Jiamei; Chang, Baoren

Community detection in complex networks is a key problem of network analysis. In this paper, a new membrane algorithm is proposed to solve the community detection in complex networks. The proposed algorithm is based on membrane systems, which consists of objects, reaction rules, and a membrane structure. Each object represents a candidate partition of a complex network, and the quality of objects is evaluated according to network modularity. The reaction rules include evolutionary rules and communication rules. Evolutionary rules are responsible for improving the quality of objects, which employ the differential evolutionary algorithm to evolve objects. Communication rules implement the information exchanged among membranes. Finally, the proposed algorithm is evaluated on synthetic, real-world networks with real partitions known and the large-scaled networks with real partitions unknown. The experimental results indicate the superior performance of the proposed algorithm in comparison with other experimental algorithms.

Advanced biologically plausible algorithms for low-level image processing

NASA Astrophysics Data System (ADS)

Gusakova, Valentina I.; Podladchikova, Lubov N.; Shaposhnikov, Dmitry G.; Markin, Sergey N.; Golovan, Alexander V.; Lee, Seong-Whan

1999-08-01

At present, in computer vision, the approach based on modeling the biological vision mechanisms is extensively developed. However, up to now, real world image processing has no effective solution in frameworks of both biologically inspired and conventional approaches. Evidently, new algorithms and system architectures based on advanced biological motivation should be developed for solution of computational problems related to this visual task. Basic problems that should be solved for creation of effective artificial visual system to process real world imags are a search for new algorithms of low-level image processing that, in a great extent, determine system performance. In the present paper, the result of psychophysical experiments and several advanced biologically motivated algorithms for low-level processing are presented. These algorithms are based on local space-variant filter, context encoding visual information presented in the center of input window, and automatic detection of perceptually important image fragments. The core of latter algorithm are using local feature conjunctions such as noncolinear oriented segment and composite feature map formation. Developed algorithms were integrated into foveal active vision model, the MARR. It is supposed that proposed algorithms may significantly improve model performance while real world image processing during memorizing, search, and recognition.

The cognitive and neural basis of option generation and subsequent choice.

PubMed

Kaiser, Stefan; Simon, Joe J; Kalis, Annemarie; Schweizer, Sophie; Tobler, Philippe N; Mojzisch, Andreas

2013-12-01

Decision-making research has thoroughly investigated how people choose from a set of externally provided options. However, in ill-structured real-world environments, possible options for action are not defined by the situation but have to be generated by the agent. Here, we apply behavioral analysis (Study 1) and functional magnetic resonance imaging (Study 2) to investigate option generation and subsequent choice. For this purpose, we employ a new experimental task that requires participants to generate options for simple real-world scenarios and to subsequently decide among the generated options. Correlational analysis with a cognitive test battery suggests that retrieval of options from long-term memory is a relevant process during option generation. The results of the fMRI study demonstrate that option generation in simple real-world scenarios recruits the anterior prefrontal cortex. Furthermore, we show that choice behavior and its neural correlates differ between self-generated and externally provided options. Specifically, choice between self-generated options is associated with stronger recruitment of the dorsal anterior cingulate cortex. This impact of option generation on subsequent choice underlines the need for an expanded model of decision making to accommodate choice between self-generated options.

Distorted images of one's own body activates the prefrontal cortex and limbic/paralimbic system in young women: a functional magnetic resonance imaging study.

PubMed

Kurosaki, Mitsuhaya; Shirao, Naoko; Yamashita, Hidehisa; Okamoto, Yasumasa; Yamawaki, Shigeto

2006-02-15

Our aim was to study the gender differences in brain activation upon viewing visual stimuli of distorted images of one's own body. We performed functional magnetic resonance imaging on 11 healthy young men and 11 healthy young women using the "body image tasks" which consisted of fat, real, and thin shapes of the subject's own body. Comparison of the brain activation upon performing the fat-image task versus real-image task showed significant activation of the bilateral prefrontal cortex and left parahippocampal area including the amygdala in the women, and significant activation of the right occipital lobe including the primary and secondary visual cortices in the men. Comparison of brain activation upon performing the thin-image task versus real-image task showed significant activation of the left prefrontal cortex, left limbic area including the cingulate gyrus and paralimbic area including the insula in women, and significant activation of the occipital lobe including the left primary and secondary visual cortices in men. These results suggest that women tend to perceive distorted images of their own bodies by complex cognitive processing of emotion, whereas men tend to perceive distorted images of their own bodies by object visual processing and spatial visual processing.

Motivated to Retrieve: How Often Are You Willing to Go Back to the Well when the Well Is Dry?

ERIC Educational Resources Information Center

Dougherty, Michael R.; Harbison, J. Isaiah

2007-01-01

Despite the necessity of the decision to terminate memory search in many real-world memory tasks, little experimental work has investigated the underlying processes. In this study, the authors investigated termination decisions in free recall by providing participants an open-ended retrieval interval and requiring them to press a stop button when…

Failures of Sustained Attention in Life, Lab, and Brain: Ecological Validity of the SART

ERIC Educational Resources Information Center

Smilek, Daniel; Carriere, Jonathan S. A.; Cheyne, J. Allan

2010-01-01

The Sustained Attention to Response Task (SART) is a widely used tool in cognitive neuroscience increasingly employed to identify brain regions associated with failures of sustained attention. An important claim of the SART is that it is significantly related to real-world problems of sustained attention such as those experienced by TBI and ADHD…

Sure, They Can Build It But...Manufacturing Students Need Process Planning Skills

ERIC Educational Resources Information Center

Obi, Samuel C.

2007-01-01

Manufacturing systems students usually complete lab projects for class requirements. However, they often do not have an idea how many resources such as time, tools, and materials they will need to complete a project until they get into constructing it. Yet one of the first tasks of real-world manufacturing personnel when they receive new product…

Are Individual Differences in Performance on Perceptual and Cognitive Optimization Problems Determined by General Intelligence?

ERIC Educational Resources Information Center

Burns, Nicholas R.; Lee, Michael D.; Vickers, Douglas

2006-01-01

Studies of human problem solving have traditionally used deterministic tasks that require the execution of a systematic series of steps to reach a rational and optimal solution. Most real-world problems, however, are characterized by uncertainty, the need to consider an enormous number of variables and possible courses of action at each stage in…

The roles of COMT val158met status and aviation expertise in flight simulator performance and cognitive ability.

PubMed

Kennedy, Q; Taylor, J L; Noda, A; Adamson, M; Murphy, G M; Zeitzer, J M; Yesavage, J A

2011-09-01

The polymorphic variation in the val158met position of the catechol-O-methyltransferase (COMT) gene is associated with differences in executive performance, processing speed, and attention. The purpose of this study is: (1) replicate previous COMT val158met findings on cognitive performance; (2) determine whether COMT val158met effects extend to a real-world task, aircraft navigation performance in a flight simulator; and (3) determine if aviation expertise moderates any effect of COMT val158met status on flight simulator performance. One hundred seventy two pilots aged 41-69 years, who varied in level of aviation training and experience, completed flight simulator, cognitive, and genetic assessments. Results indicate that although no COMT effect was found for an overall measure of flight performance, a positive effect of the met allele was detected for two aspects of cognitive ability: executive functioning and working memory performance. Pilots with the met/met genotype benefited more from increased levels of expertise than other participants on a traffic avoidance measure, which is a component of flight simulator performance. These preliminary results indicate that COMT val158met polymorphic variation can affect a real-world task.

Neural mechanisms tracking popularity in real-world social networks.

PubMed

Zerubavel, Noam; Bearman, Peter S; Weber, Jochen; Ochsner, Kevin N

2015-12-08

Differences in popularity are a key aspect of status in virtually all human groups and shape social interactions within them. Little is known, however, about how we track and neurally represent others' popularity. We addressed this question in two real-world social networks using sociometric methods to quantify popularity. Each group member (perceiver) viewed faces of every other group member (target) while whole-brain functional MRI data were collected. Independent functional localizer tasks were used to identify brain systems supporting affective valuation (ventromedial prefrontal cortex, ventral striatum, amygdala) and social cognition (dorsomedial prefrontal cortex, precuneus, temporoparietal junction), respectively. During the face-viewing task, activity in both types of neural systems tracked targets' sociometric popularity, even when controlling for potential confounds. The target popularity-social cognition system relationship was mediated by valuation system activity, suggesting that observing popular individuals elicits value signals that facilitate understanding their mental states. The target popularity-valuation system relationship was strongest for popular perceivers, suggesting enhanced sensitivity to differences among other group members' popularity. Popular group members also demonstrated greater interpersonal sensitivity by more accurately predicting how their own personalities were perceived by other individuals in the social network. These data offer insights into the mechanisms by which status guides social behavior.

The Roles of COMT val158met Status and Aviation Expertise in Flight Simulator Performance and Cognitive Ability

PubMed Central

Taylor, J. L.; Noda, A.; Adamson, M.; Murphy, G. M.; Zeitzer, J. M.; Yesavage, J. A.

2011-01-01

The polymorphic variation in the val158met position of the catechol-O-methyltransferase (COMT) gene is associated with differences in executive performance, processing speed, and attention. The purpose of this study is: (1) replicate previous COMT val158met findings on cognitive performance; (2) determine whether COMT val158met effects extend to a real-world task, aircraft navigation performance in a flight simulator; and (3) determine if aviation expertise moderates any effect of COMT val158met status on flight simulator performance. One hundred seventy two pilots aged 41–69 years, who varied in level of aviation training and experience, completed flight simulator, cognitive, and genetic assessments. Results indicate that although no COMT effect was found for an overall measure of flight performance, a positive effect of the met allele was detected for two aspects of cognitive ability: executive functioning and working memory performance. Pilots with the met/met genotype benefited more from increased levels of expertise than other participants on a traffic avoidance measure, which is a component of flight simulator performance. These preliminary results indicate that COMT val158met polymorphic variation can affect a real-world task. PMID:21193954

Spatio-temporal networks: reachability, centrality and robustness.

PubMed

Williams, Matthew J; Musolesi, Mirco

2016-06-01

Recent advances in spatial and temporal networks have enabled researchers to more-accurately describe many real-world systems such as urban transport networks. In this paper, we study the response of real-world spatio-temporal networks to random error and systematic attack, taking a unified view of their spatial and temporal performance. We propose a model of spatio-temporal paths in time-varying spatially embedded networks which captures the property that, as in many real-world systems, interaction between nodes is non-instantaneous and governed by the space in which they are embedded. Through numerical experiments on three real-world urban transport systems, we study the effect of node failure on a network's topological, temporal and spatial structure. We also demonstrate the broader applicability of this framework to three other classes of network. To identify weaknesses specific to the behaviour of a spatio-temporal system, we introduce centrality measures that evaluate the importance of a node as a structural bridge and its role in supporting spatio-temporally efficient flows through the network. This exposes the complex nature of fragility in a spatio-temporal system, showing that there is a variety of failure modes when a network is subject to systematic attacks.

Neural activity during natural viewing of Sesame Street statistically predicts test scores in early childhood.

PubMed

Cantlon, Jessica F; Li, Rosa

2013-01-01

It is not currently possible to measure the real-world thought process that a child has while observing an actual school lesson. However, if it could be done, children's neural processes would presumably be predictive of what they know. Such neural measures would shed new light on children's real-world thought. Toward that goal, this study examines neural processes that are evoked naturalistically, during educational television viewing. Children and adults all watched the same Sesame Street video during functional magnetic resonance imaging (fMRI). Whole-brain intersubject correlations between the neural timeseries from each child and a group of adults were used to derive maps of "neural maturity" for children. Neural maturity in the intraparietal sulcus (IPS), a region with a known role in basic numerical cognition, predicted children's formal mathematics abilities. In contrast, neural maturity in Broca's area correlated with children's verbal abilities, consistent with prior language research. Our data show that children's neural responses while watching complex real-world stimuli predict their cognitive abilities in a content-specific manner. This more ecologically natural paradigm, combined with the novel measure of "neural maturity," provides a new method for studying real-world mathematics development in the brain.

Teaching the Dynamics of Framing Competitions

ERIC Educational Resources Information Center

Rinke, Eike Mark

2012-01-01

Framing theory is one of the most thriving and complex fields of communication theory, and as such it has grown to be an integral part of many political communication, public opinion, and communication theory courses. Part of the complexity stems from scholars' efforts to develop accounts of framing processes that are closer to the "real world" of…

Exploring Creativity by Linking Complexity Learning to Futures-Based Research Proposals

ERIC Educational Resources Information Center

Bolton, Michael J.

2009-01-01

Traditional teaching models based on linear approaches to instruction arguably are of limited value in preparing students to handle complex, dynamic real-world problems. As such, they are undergoing increased scrutiny by scholars in various disciplines. The author argues that nonlinear approaches to higher education such as those founded on…

Somatics in Action: How "I Feel Three-Dimensional and Real" Improves Dance Education and Training

ERIC Educational Resources Information Center

Kearns, Lauren W.

2010-01-01

The contemporary dance world, both in academic and professional settings, asks dancers to consistently engage with increasingly complex conceptual and physical dance work. Dancers in both settings must assimilate complex movement patterns, combine the technical nuances of multiple genres, reflect upon and critically assess their dancing, and…

Topics in Complexity: From Physical to Life Science Systems

NASA Astrophysics Data System (ADS)

Charry, Pedro David Manrique

Complexity seeks to unwrap the mechanisms responsible for collective phenomena across the physical, biological, chemical, economic and social sciences. This thesis investigates real-world complex dynamical systems ranging from the quantum/natural domain to the social domain. The following novel understandings are developed concerning these systems' out-of-equilibrium and nonlinear behavior. Standard quantum techniques show divergent outcomes when a quantum system comprising more than one subunit is far from thermodynamic equilibrium. Abnormal photon inter-arrival times help fulfill the metabolic needs of a terrestrial photosynthetic bacterium. Spatial correlations within incident light can act as a driving mechanism for an organism's adaptation toward more ordered structures. The group dynamics of non-identical objects, whose assembly rules depend on mutual heterogeneity, yield rich transition dynamics between isolation and cohesion, with the cohesion regime reproducing a particular universal pattern commonly found in many real-world systems. Analyses of covert networks reveal collective gender superiority in the connectivity that provides benefits for system robustness and survival. Nodal migration in a network generates complex contagion profiles that lie beyond traditional approaches and yet resemble many modern-day outbreaks.

Interface Design Implications for Recalling the Spatial Configuration of Virtual Auditory Environments

NASA Astrophysics Data System (ADS)

McMullen, Kyla A.

Although the concept of virtual spatial audio has existed for almost twenty-five years, only in the past fifteen years has modern computing technology enabled the real-time processing needed to deliver high-precision spatial audio. Furthermore, the concept of virtually walking through an auditory environment did not exist. The applications of such an interface have numerous potential uses. Spatial audio has the potential to be used in various manners ranging from enhancing sounds delivered in virtual gaming worlds to conveying spatial locations in real-time emergency response systems. To incorporate this technology in real-world systems, various concerns should be addressed. First, to widely incorporate spatial audio into real-world systems, head-related transfer functions (HRTFs) must be inexpensively created for each user. The present study further investigated an HRTF subjective selection procedure previously developed within our research group. Users discriminated auditory cues to subjectively select their preferred HRTF from a publicly available database. Next, the issue of training to find virtual sources was addressed. Listeners participated in a localization training experiment using their selected HRTFs. The training procedure was created from the characterization of successful search strategies in prior auditory search experiments. Search accuracy significantly improved after listeners performed the training procedure. Next, in the investigation of auditory spatial memory, listeners completed three search and recall tasks with differing recall methods. Recall accuracy significantly decreased in tasks that required the storage of sound source configurations in memory. To assess the impacts of practical scenarios, the present work assessed the performance effects of: signal uncertainty, visual augmentation, and different attenuation modeling. Fortunately, source uncertainty did not affect listeners' ability to recall or identify sound sources. The present study also found that the presence of visual reference frames significantly increased recall accuracy. Additionally, the incorporation of drastic attenuation significantly improved environment recall accuracy. Through investigating the aforementioned concerns, the present study made initial footsteps guiding the design of virtual auditory environments that support spatial configuration recall.

Synaptic plasticity in a recurrent neural network for versatile and adaptive behaviors of a walking robot.

PubMed

Grinke, Eduard; Tetzlaff, Christian; Wörgötter, Florentin; Manoonpong, Poramate

2015-01-01

Walking animals, like insects, with little neural computing can effectively perform complex behaviors. For example, they can walk around their environment, escape from corners/deadlocks, and avoid or climb over obstacles. While performing all these behaviors, they can also adapt their movements to deal with an unknown situation. As a consequence, they successfully navigate through their complex environment. The versatile and adaptive abilities are the result of an integration of several ingredients embedded in their sensorimotor loop. Biological studies reveal that the ingredients include neural dynamics, plasticity, sensory feedback, and biomechanics. Generating such versatile and adaptive behaviors for a many degrees-of-freedom (DOFs) walking robot is a challenging task. Thus, in this study, we present a bio-inspired approach to solve this task. Specifically, the approach combines neural mechanisms with plasticity, exteroceptive sensory feedback, and biomechanics. The neural mechanisms consist of adaptive neural sensory processing and modular neural locomotion control. The sensory processing is based on a small recurrent neural network consisting of two fully connected neurons. Online correlation-based learning with synaptic scaling is applied to adequately change the connections of the network. By doing so, we can effectively exploit neural dynamics (i.e., hysteresis effects and single attractors) in the network to generate different turning angles with short-term memory for a walking robot. The turning information is transmitted as descending steering signals to the neural locomotion control which translates the signals into motor actions. As a result, the robot can walk around and adapt its turning angle for avoiding obstacles in different situations. The adaptation also enables the robot to effectively escape from sharp corners or deadlocks. Using backbone joint control embedded in the the locomotion control allows the robot to climb over small obstacles. Consequently, it can successfully explore and navigate in complex environments. We firstly tested our approach on a physical simulation environment and then applied it to our real biomechanical walking robot AMOSII with 19 DOFs to adaptively avoid obstacles and navigate in the real world.

Synaptic plasticity in a recurrent neural network for versatile and adaptive behaviors of a walking robot

PubMed Central

Grinke, Eduard; Tetzlaff, Christian; Wörgötter, Florentin; Manoonpong, Poramate

2015-01-01

Walking animals, like insects, with little neural computing can effectively perform complex behaviors. For example, they can walk around their environment, escape from corners/deadlocks, and avoid or climb over obstacles. While performing all these behaviors, they can also adapt their movements to deal with an unknown situation. As a consequence, they successfully navigate through their complex environment. The versatile and adaptive abilities are the result of an integration of several ingredients embedded in their sensorimotor loop. Biological studies reveal that the ingredients include neural dynamics, plasticity, sensory feedback, and biomechanics. Generating such versatile and adaptive behaviors for a many degrees-of-freedom (DOFs) walking robot is a challenging task. Thus, in this study, we present a bio-inspired approach to solve this task. Specifically, the approach combines neural mechanisms with plasticity, exteroceptive sensory feedback, and biomechanics. The neural mechanisms consist of adaptive neural sensory processing and modular neural locomotion control. The sensory processing is based on a small recurrent neural network consisting of two fully connected neurons. Online correlation-based learning with synaptic scaling is applied to adequately change the connections of the network. By doing so, we can effectively exploit neural dynamics (i.e., hysteresis effects and single attractors) in the network to generate different turning angles with short-term memory for a walking robot. The turning information is transmitted as descending steering signals to the neural locomotion control which translates the signals into motor actions. As a result, the robot can walk around and adapt its turning angle for avoiding obstacles in different situations. The adaptation also enables the robot to effectively escape from sharp corners or deadlocks. Using backbone joint control embedded in the the locomotion control allows the robot to climb over small obstacles. Consequently, it can successfully explore and navigate in complex environments. We firstly tested our approach on a physical simulation environment and then applied it to our real biomechanical walking robot AMOSII with 19 DOFs to adaptively avoid obstacles and navigate in the real world. PMID:26528176

Investigating the application of AOP methodology in development of Financial Accounting Software using Eclipse-AJDT Environment

NASA Astrophysics Data System (ADS)

Sharma, Amita; Sarangdevot, S. S.

2010-11-01

Aspect-Oriented Programming (AOP) methodology has been investigated in development of real world business application software—Financial Accounting Software. Eclipse-AJDT environment has been used as open source enhanced IDE support for programming in AOP language—Aspect J. Crosscutting concerns have been identified and modularized as aspects. This reduces the complexity of the design considerably due to elimination of code scattering and tangling. Improvement in modularity, quality and performance is achieved. The study concludes that AOP methodology in Eclipse-AJDT environment offers powerful support for modular design and implementation of real world quality business software.

Expanding the Reach of Physics-Engaging Students in Interdisciplinary Research Involving complex, real-world situation

NASA Astrophysics Data System (ADS)

Bililign, Solomon

2014-03-01

Physics plays a very important role in most interdisciplinary efforts and can provide a solid foundation for students. Retention of students in STEM areas can be facilitated by enhanced interdisciplinary education and research since students are strongly attracted to research with societal relevance and show increasing enthusiasm about problems that have practical consequences. One such area of research is a collaborative Earth System Science. The Earth System is dynamic and complex. It is comprised of diverse components that interact. By providing students the opportunities to work in interdisciplinary groups on a problem that reflects a complex, real-world situation they can see the linkages between components of the Earth system that encompass climate and all its components (weather precipitation, temperature, etc.) and technology development and deployment of sensors and sensor networks and social impacts. By involving students in the creation of their own personalized professional development plan, students are more focused and engaged and are more likely to remain in the program.

Tackling some of the most intricate geophysical challenges via high-performance computing

NASA Astrophysics Data System (ADS)

Khosronejad, A.

2016-12-01

Recently, world has been witnessing significant enhancements in computing power of supercomputers. Computer clusters in conjunction with the advanced mathematical algorithms has set the stage for developing and applying powerful numerical tools to tackle some of the most intricate geophysical challenges that today`s engineers face. One such challenge is to understand how turbulent flows, in real-world settings, interact with (a) rigid and/or mobile complex bed bathymetry of waterways and sea-beds in the coastal areas; (b) objects with complex geometry that are fully or partially immersed; and (c) free-surface of waterways and water surface waves in the coastal area. This understanding is especially important because the turbulent flows in real-world environments are often bounded by geometrically complex boundaries, which dynamically deform and give rise to multi-scale and multi-physics transport phenomena, and characterized by multi-lateral interactions among various phases (e.g. air/water/sediment phases). Herein, I present some of the multi-scale and multi-physics geophysical fluid mechanics processes that I have attempted to study using an in-house high-performance computational model, the so-called VFS-Geophysics. More specifically, I will present the simulation results of turbulence/sediment/solute/turbine interactions in real-world settings. Parts of the simulations I present are performed to gain scientific insights into the processes such as sand wave formation (A. Khosronejad, and F. Sotiropoulos, (2014), Numerical simulation of sand waves in a turbulent open channel flow, Journal of Fluid Mechanics, 753:150-216), while others are carried out to predict the effects of climate change and large flood events on societal infrastructures ( A. Khosronejad, et al., (2016), Large eddy simulation of turbulence and solute transport in a forested headwater stream, Journal of Geophysical Research:, doi: 10.1002/2014JF003423).

Handling Real-World Context Awareness, Uncertainty and Vagueness in Real-Time Human Activity Tracking and Recognition with a Fuzzy Ontology-Based Hybrid Method

PubMed Central

Díaz-Rodríguez, Natalia; Cadahía, Olmo León; Cuéllar, Manuel Pegalajar; Lilius, Johan; Calvo-Flores, Miguel Delgado

2014-01-01

Human activity recognition is a key task in ambient intelligence applications to achieve proper ambient assisted living. There has been remarkable progress in this domain, but some challenges still remain to obtain robust methods. Our goal in this work is to provide a system that allows the modeling and recognition of a set of complex activities in real life scenarios involving interaction with the environment. The proposed framework is a hybrid model that comprises two main modules: a low level sub-activity recognizer, based on data-driven methods, and a high-level activity recognizer, implemented with a fuzzy ontology to include the semantic interpretation of actions performed by users. The fuzzy ontology is fed by the sub-activities recognized by the low level data-driven component and provides fuzzy ontological reasoning to recognize both the activities and their influence in the environment with semantics. An additional benefit of the approach is the ability to handle vagueness and uncertainty in the knowledge-based module, which substantially outperforms the treatment of incomplete and/or imprecise data with respect to classic crisp ontologies. We validate these advantages with the public CAD-120 dataset (Cornell Activity Dataset), achieving an accuracy of 90.1% and 91.07% for low-level and high-level activities, respectively. This entails an improvement over fully data-driven or ontology-based approaches. PMID:25268914

Executive Functioning and School Performance Among Pediatric Survivors of Complex Congenital Heart Disease

PubMed Central

Gerstle, Melissa; Beebe, Dean W.; Drotar, Dennis; Cassedy, Amy; Marino, Bradley S.

2016-01-01

Objective To investigate the presence and severity of real-world impairments in executive functioning– responsible for children’s regulatory skills (metacognition, behavioral regulation) – and its potential impact on school performance among pediatric survivors of complex congenital heart disease (CHD). Study design Survivors of complex CHD aged 8–16 years (n=143)and their parents/guardians from a regional CHD survivor registry participated (81% participation rate). Parents completed proxy measures of executive functioning, school competency, and school-related quality of life (QOL). Patients also completed a measure of school QOL and underwent IQ testing. Patients were categorized into two groups based on heart lesion complexity: two-ventricle or single-ventricle. Results Survivors of complex CHD performed significantly worse than norms for executive functioning, IQ, school competency, and school QOL. Metacognition was more severely affected than behavioral regulation, and metacognitive deficits were more often present in older children. Even after taking into account demographic factors, disease severity, and IQ, metacognition uniquely and strongly predicted poorer school performance. In exploratory analyses, patients with single-ventricle lesions were rated as having lower school competency and school QOL, and patients with two-ventricle lesions were rated as having poorer behavioral regulation. Conclusions Survivors of complex CHD experience greater executive functioning difficulties than healthy peers, with metacognition particularly impacted and particularly relevant for day-to-day school performance. Especially in older children, clinicians should watch for metacognitive deficits, such as problems with organization, planning, self-monitoring, and follow-through on tasks. PMID:26875011

Real-world health outcomes in adults with moderate-to-severe psoriasis in the United States: a population study using electronic health records to examine patient-perceived treatment effectiveness, medication use, and healthcare resource utilization.

PubMed

Armstrong, April W; Foster, Shonda A; Comer, Brian S; Lin, Chen-Yen; Malatestinic, William; Burge, Russel; Goldblum, Orin

2018-06-28

Little is known regarding real-world health outcomes data among US psoriasis patients, but electronic health records (EHR) that collect structured data at point-of-care may provide opportunities to investigate real-world health outcomes among psoriasis patients. Our objective was to investigate patient-perceived treatment effectiveness, patterns of medication use (duration, switching, and/or discontinuation), healthcare resource utilization, and medication costs using real-world data from psoriasis patients. Data for adults (≥18-years) with a dermatology provider-given diagnosis of psoriasis from 9/2014-9/2015 were obtained from dermatology practices using a widely used US dermatology-specific EHR containing over 500,000 psoriasis patients. Disease severity was captured by static physician's global assessment and body surface area. Patient-perceived treatment effectiveness was assessed by a pre-defined question. Treatment switching and duration were documented. Reasons for discontinuations were assessed using pre-defined selections. Healthcare resource utilization was defined by visit frequency and complexity. From 82,621 patients with psoriasis during the study period, patient-perceived treatment effectiveness was investigated in 2200 patients. The proportion of patients reporting "strongly agree" when asked if their treatment was effective was highest for biologics (73%) and those reporting treatment adherence (55%). In 16,000 patients who received oral systemics and 21,087 patients who received biologics, median treatment duration was longer for those who received biologics (160 vs. 113 days, respectively). Treatment switching was less frequent among patients on systemic monotherapies compared to those on combination therapies. The most common reason for discontinuing biologics was loss of efficacy; the most common reason for discontinuing orals was side effects. In 28,754 patients, higher disease severity was associated with increased healthcare resource utilization (increased visit frequency and complexity). When compared between treatment groups (n = 10,454), healthcare resource utilization was highest for phototherapy. Annual medication costs were higher for biologics ($21,977) than oral systemics ($3413). Real-world research using a widely implemented dermatology EHR provided valuable insights on patient perceived treatment effectiveness, patterns of medication usage, healthcare resource utilization, and medication costs for psoriasis patients in the US. This study and others utilizing EHRs for real-world research may assist clinical and payer decisions regarding the management of psoriasis.

Statistics of natural binaural sounds.

PubMed

Młynarski, Wiktor; Jost, Jürgen

2014-01-01

Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD) and level (ILD) disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA). Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

Statistics of Natural Binaural Sounds

PubMed Central

Młynarski, Wiktor; Jost, Jürgen

2014-01-01

Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD) and level (ILD) disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA). Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction. PMID:25285658

Blur Detection is Unaffected by Cognitive Load.

PubMed

Loschky, Lester C; Ringer, Ryan V; Johnson, Aaron P; Larson, Adam M; Neider, Mark; Kramer, Arthur F

2014-03-01

Blur detection is affected by retinal eccentricity, but is it also affected by attentional resources? Research showing effects of selective attention on acuity and contrast sensitivity suggests that allocating attention should increase blur detection. However, research showing that blur affects selection of saccade targets suggests that blur detection may be pre-attentive. To investigate this question, we carried out experiments in which viewers detected blur in real-world scenes under varying levels of cognitive load manipulated by the N -back task. We used adaptive threshold estimation to measure blur detection thresholds at 0°, 3°, 6°, and 9° eccentricity. Participants carried out blur detection as a single task, a single task with to-be-ignored letters, or an N-back task with four levels of cognitive load (0, 1, 2, or 3-back). In Experiment 1, blur was presented gaze-contingently for occasional single eye fixations while participants viewed scenes in preparation for an easy picture recognition memory task, and the N -back stimuli were presented auditorily. The results for three participants showed a large effect of retinal eccentricity on blur thresholds, significant effects of N -back level on N -back performance, scene recognition memory, and gaze dispersion, but no effect of N -back level on blur thresholds. In Experiment 2, we replicated Experiment 1 but presented the images tachistoscopically for 200 ms (half with, half without blur), to determine whether gaze-contingent blur presentation in Experiment 1 had produced attentional capture by blur onset during a fixation, thus eliminating any effect of cognitive load on blur detection. The results with three new participants replicated those of Experiment 1, indicating that the use of gaze-contingent blur presentation could not explain the lack of effect of cognitive load on blur detection. Thus, apparently blur detection in real-world scene images is unaffected by attentional resources, as manipulated by the cognitive load produced by the N -back task.

Modelling and simulation of complex sociotechnical systems: envisioning and analysing work environments

PubMed Central

Hettinger, Lawrence J.; Kirlik, Alex; Goh, Yang Miang; Buckle, Peter

2015-01-01

Accurate comprehension and analysis of complex sociotechnical systems is a daunting task. Empirically examining, or simply envisioning the structure and behaviour of such systems challenges traditional analytic and experimental approaches as well as our everyday cognitive capabilities. Computer-based models and simulations afford potentially useful means of accomplishing sociotechnical system design and analysis objectives. From a design perspective, they can provide a basis for a common mental model among stakeholders, thereby facilitating accurate comprehension of factors impacting system performance and potential effects of system modifications. From a research perspective, models and simulations afford the means to study aspects of sociotechnical system design and operation, including the potential impact of modifications to structural and dynamic system properties, in ways not feasible with traditional experimental approaches. This paper describes issues involved in the design and use of such models and simulations and describes a proposed path forward to their development and implementation. Practitioner Summary: The size and complexity of real-world sociotechnical systems can present significant barriers to their design, comprehension and empirical analysis. This article describes the potential advantages of computer-based models and simulations for understanding factors that impact sociotechnical system design and operation, particularly with respect to process and occupational safety. PMID:25761227

MAP-IT: A Practical Tool for Planning Complex Behavior Modification Interventions.

PubMed

Hansen, Sylvia; Kanning, Martina; Lauer, Romy; Steinacker, Jürgen M; Schlicht, Wolfgang

2017-09-01

Health research often aims to prevent noncommunicable diseases and to improve individual and public health by discovering intervention strategies that are effective in changing behavior and/or environments that are detrimental to one's health. Ideally, findings from original research support practitioners in planning and implementing effective interventions. Unfortunately, interventions often fail to overcome the translational block between science and practice. They often ignore theoretical knowledge, overlook empirical evidence, and underrate the impact of the environment. Accordingly, sustainable changes in individual behavior and/or the environment are difficult to achieve. Developing theory-driven and evidence-based interventions in the real world is a complex task. Existing implementation frameworks and theories often do not meet the needs of health practitioners. The purpose of this article is to synthesize existing frameworks and to provide a tool, the Matrix Assisting Practitioner's Intervention Planning Tool (MAP-IT), that links research to practice and helps practitioners to design multicomponent interventions. In this article, we use physical activity of older adults as an example to explain the rationale of MAP-IT. In MAP-IT, individual as well as environmental mechanisms are listed and behavior change techniques are linked to these mechanisms and to intervention components. MAP-IT is theory-driven and evidence-based. It is time-saving and helpful for practitioners when planning complex interventions.

Using Geometry-Based Metrics as Part of Fitness-for-Purpose Evaluations of 3D City Models

NASA Astrophysics Data System (ADS)

Wong, K.; Ellul, C.

2016-10-01

Three-dimensional geospatial information is being increasingly used in a range of tasks beyond visualisation. 3D datasets, however, are often being produced without exact specifications and at mixed levels of geometric complexity. This leads to variations within the models' geometric and semantic complexity as well as the degree of deviation from the corresponding real world objects. Existing descriptors and measures of 3D data such as CityGML's level of detail are perhaps only partially sufficient in communicating data quality and fitness-for-purpose. This study investigates whether alternative, automated, geometry-based metrics describing the variation of complexity within 3D datasets could provide additional relevant information as part of a process of fitness-for-purpose evaluation. The metrics include: mean vertex/edge/face counts per building; vertex/face ratio; minimum 2D footprint area and; minimum feature length. Each metric was tested on six 3D city models from international locations. The results show that geometry-based metrics can provide additional information on 3D city models as part of fitness-for-purpose evaluations. The metrics, while they cannot be used in isolation, may provide a complement to enhance existing data descriptors if backed up with local knowledge, where possible.

The Linear Quadratic Gaussian Multistage Game with Nonclassical Information Pattern Using a Direct Solution Method

NASA Astrophysics Data System (ADS)

Clemens, Joshua William

Game theory has application across multiple fields, spanning from economic strategy to optimal control of an aircraft and missile on an intercept trajectory. The idea of game theory is fascinating in that we can actually mathematically model real-world scenarios and determine optimal decision making. It may not always be easy to mathematically model certain real-world scenarios, nonetheless, game theory gives us an appreciation for the complexity involved in decision making. This complexity is especially apparent when the players involved have access to different information upon which to base their decision making (a nonclassical information pattern). Here we will focus on the class of adversarial two-player games (sometimes referred to as pursuit-evasion games) with nonclassical information pattern. We present a two-sided (simultaneous) optimization solution method for the two-player linear quadratic Gaussian (LQG) multistage game. This direct solution method allows for further interpretation of each player's decision making (strategy) as compared to previously used formal solution methods. In addition to the optimal control strategies, we present a saddle point proof and we derive an expression for the optimal performance index value. We provide some numerical results in order to further interpret the optimal control strategies and to highlight real-world application of this game-theoretic optimal solution.

Efficiency of goal-oriented communicating agents in different graph topologies: A study with Internet crawlers

NASA Astrophysics Data System (ADS)

Lőrincz, András; Lázár, Katalin A.; Palotai, Zsolt

2007-05-01

To what extent does the communication make a goal-oriented community efficient in different topologies? In order to gain insight into this problem, we study the influence of learning method as well as that of the topology of the environment on the communication efficiency of crawlers in quest of novel information in different topics on the Internet. Individual crawlers employ selective learning, function approximation-based reinforcement learning (RL), and their combination. Selective learning, in effect, modifies the starting URL lists of the crawlers, whilst RL alters the URL orderings. Real data have been collected from the web and scale-free worlds, scale-free small world (SFSW), and random world environments (RWEs) have been created by link reorganization. In our previous experiments [ Zs. Palotai, Cs. Farkas, A. Lőrincz, Is selection optimal in scale-free small worlds?, ComPlexUs 3 (2006) 158-168], the crawlers searched for novel, genuine documents and direct communication was not possible. Herein, our finding is reproduced: selective learning performs the best and RL the worst in SFSW, whereas the combined, i.e., selective learning coupled with RL is the best-by a slight margin-in scale-free worlds. This effect is demonstrated to be more pronounced when the crawlers search for different topic-specific documents: the relative performance of the combined learning algorithm improves in all worlds, i.e., in SFSW, in SFW, and in RWE. If the tasks are more complex and the work sharing is enforced by the environment then the combined learning algorithm becomes at least equal, even superior to both the selective and the RL algorithms in most cases, irrespective of the efficiency of communication. Furthermore, communication improves the performance by a large margin and adaptive communication is advantageous in the majority of the cases.

Real-time tracking and virtual endoscopy in cone-beam CT-guided surgery of the sinuses and skull base in a cadaver model.

PubMed

Prisman, Eitan; Daly, Michael J; Chan, Harley; Siewerdsen, Jeffrey H; Vescan, Allan; Irish, Jonathan C

2011-01-01

Custom software was developed to integrate intraoperative cone-beam computed tomography (CBCT) images with endoscopic video for surgical navigation and guidance. A cadaveric head was used to assess the accuracy and potential clinical utility of the following functionality: (1) real-time tracking of the endoscope in intraoperative 3-dimensional (3D) CBCT; (2) projecting an orthogonal reconstructed CBCT image, at or beyond the endoscope, which is parallel to the tip of the endoscope corresponding to the surgical plane; (3) virtual reality fusion of endoscopic video and 3D CBCT surface rendering; and (4) overlay of preoperatively defined contours of anatomical structures of interest. Anatomical landmarks were contoured in CBCT of a cadaveric head. An experienced endoscopic surgeon was oriented to the software and asked to rate the utility of the navigation software in carrying out predefined surgical tasks. Utility was evaluated using a rating scale for: (1) safely completing the task; and (2) potential for surgical training. Surgical tasks included: (1) uncinectomy; (2) ethmoidectomy; (3) sphenoidectomy/pituitary resection; and (4) clival resection. CBCT images were updated following each ablative task. As a teaching tool, the software was evaluated as "very useful" for all surgical tasks. Regarding safety and task completion, the software was evaluated as "no advantage" for task (1), "minimal" for task (2), and "very useful" for tasks (3) and (4). Landmark identification for structures behind bone was "very useful" for both categories. The software increased surgical confidence in safely completing challenging ablative tasks by presenting real-time image guidance for highly complex ablative procedures. In addition, such technology offers a valuable teaching aid to surgeons in training. Copyright © 2011 American Rhinologic Society-American Academy of Otolaryngic Allergy, LLC.

Global attention facilitates the planning, but not execution of goal-directed reaches.

PubMed

McCarthy, J Daniel; Song, Joo-Hyun

2016-07-01

In daily life, humans interact with multiple objects in complex environments. A large body of literature demonstrates that target selection is biased toward recently attended features, such that reaches are faster and trajectory curvature is reduced when target features (i.e., color) are repeated (priming of pop-out). In the real world, however, objects are comprised of several features-some of which may be more suitable for action than others. When fetching a mug from the cupboard, for example, attention not only has to be allocated to the object, but also the handle. To date, no study has investigated the impact of hierarchical feature organization on target selection for action. Here, we employed a color-oddity search task in which targets were Pac-men (i.e., a circle with a triangle cut out) oriented to be either consistent or inconsistent with the percept of a global Kanizsa triangle. We found that reaches were initiated faster when a task-irrelevant illusory figure was present independent of color repetition. Additionally, consistent with priming of pop-out, both reach planning and execution were facilitated when local target colors were repeated, regardless of whether a global figure was present. We also demonstrated that figures defined by illusory, but not real contours, afforded an early target selection benefit. In sum, these findings suggest that when local targets are perceptually grouped to form an illusory surface, attention quickly spreads across the global figure and facilitates the early stage of reach planning, but not execution. In contrast, local color priming is evident throughout goal-directed reaching.

Development of an audio-based virtual gaming environment to assist with navigation skills in the blind.

PubMed

Connors, Erin C; Yazzolino, Lindsay A; Sánchez, Jaime; Merabet, Lotfi B

2013-03-27

Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the blind. Using only audio based cues and set within the context of a video game metaphor, users gather relevant spatial information regarding a building's layout. This allows the user to develop an accurate spatial cognitive map of a large-scale three-dimensional space that can be manipulated for the purposes of a real indoor navigation task. After game play, participants are then assessed on their ability to navigate within the target physical building represented in the game. Preliminary results suggest that early blind users were able to acquire relevant information regarding the spatial layout of a previously unfamiliar building as indexed by their performance on a series of navigation tasks. These tasks included path finding through the virtual and physical building, as well as a series of drop off tasks. We find that the immersive and highly interactive nature of the AbES software appears to greatly engage the blind user to actively explore the virtual environment. Applications of this approach may extend to larger populations of visually impaired individuals.

SonoNet: Real-Time Detection and Localisation of Fetal Standard Scan Planes in Freehand Ultrasound.

PubMed

Baumgartner, Christian F; Kamnitsas, Konstantinos; Matthew, Jacqueline; Fletcher, Tara P; Smith, Sandra; Koch, Lisa M; Kainz, Bernhard; Rueckert, Daniel

2017-11-01

Identifying and interpreting fetal standard scan planes during 2-D ultrasound mid-pregnancy examinations are highly complex tasks, which require years of training. Apart from guiding the probe to the correct location, it can be equally difficult for a non-expert to identify relevant structures within the image. Automatic image processing can provide tools to help experienced as well as inexperienced operators with these tasks. In this paper, we propose a novel method based on convolutional neural networks, which can automatically detect 13 fetal standard views in freehand 2-D ultrasound data as well as provide a localization of the fetal structures via a bounding box. An important contribution is that the network learns to localize the target anatomy using weak supervision based on image-level labels only. The network architecture is designed to operate in real-time while providing optimal output for the localization task. We present results for real-time annotation, retrospective frame retrieval from saved videos, and localization on a very large and challenging dataset consisting of images and video recordings of full clinical anomaly screenings. We found that the proposed method achieved an average F1-score of 0.798 in a realistic classification experiment modeling real-time detection, and obtained a 90.09% accuracy for retrospective frame retrieval. Moreover, an accuracy of 77.8% was achieved on the localization task.

What does Batman think about SpongeBob? children's understanding of the fantasy/fantasy distinction.

PubMed

Skolnick, Deena; Bloom, Paul

2006-08-01

Young children reliably distinguish reality from fantasy; they know that their friends are real and that Batman is not. But it is an open question whether they appreciate, as adults do, that there are multiple fantasy worlds. We test this by asking children and adults about fictional characters' beliefs about other characters who exist either within the same world (e.g., Batman and Robin) or in different worlds (e.g., Batman and SpongeBob). Study 1 found that although both adults and young children distinguish between within-world and across-world types of character relationships, the children make an unexpected mistake: they often claim that Batman thinks that Robin is make believe. Study 2 used a less explicit task, exploring intuitions about the actions of characters-whom they could see, touch, and talk to--and found that children show a mature appreciation of the ontology of fictional worlds.

Integration of ICT Methods for Teaching Science and Astronomy to Students and Teachers

NASA Astrophysics Data System (ADS)

Ghosh, Sumit; Chary, Naveen; Raghavender, G.; Aslam, Syed

All children start out as scientist, full of curiosity and questions about the world, but schools eventually destroy their curiosity. In an effective teaching and learning process, the most challenging task is to motivate the students. As the science subjects are more abstract and complex, the job of teachers become even more daunting. We have devised an innovative idea of integrating ICT methods for teaching space science to students and teachers. In a third world country like India, practical demonstrations are given less importance and much emphasis is on theoretical aspects. Even the teachers are not trained or aware of the basic concepts. With the intention of providing the students and as well as the teachers more practical, real-time situations, we have incorporated innovative techniques like video presentation, animations, experimental models, do-yourself-kits etc. In addition to these we provide hands on experience on some scientific instruments like telescope, Laser. ICT has the potential to teach complex science topics to students and teachers in a safe environment and cost effective manner. The students are provided with a sense of adventure, wherein now they can manipulate parameters, contexts and environment and can try different scenarios and in the process they not only learn science but also the content and also the reasoning behind the content. The response we have obtained is very encouraging and students as well as teachers have acknowledged that they have learnt new things, which up to now they were ignorant of.