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Kim N.,Ulsan National Institute of Science and Technology | Joo J.,Inje University | Rothrock L.,Pensylvania State University | Wysk R.,North Carolina State University | Son Y.-J.,University of Arizona
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

In this paper, we propose a novel agent-based simulation modeling of human behaviors. A conceptual framework of human behavioral simulation is suggested using the ecological definition of affordances in order to mimic perception-based human actions interacting with the environment. A simulation example of a 'warehouse fire evacuation' is illustrated to demonstrate the applicability of the proposed framework. The perception-based human behaviors and planning algorithms are adapted and embedded within human agent models using the Static and Dynamic Floor Field Indicators, which represent the evacuee's prior knowledge of the floor layout and perceivable information of dynamic environmental changes, respectively. The proposed framework is expected to capture the natural manners in which humans participate in systems and enhance the simulation fidelity by incorporating cognitive intent into human behavior simulations. © 2011 Springer-Verlag. Source


Koehler K.,German Sport University Cologne | Koehler K.,Pensylvania State University | Abel T.,German Sport University Cologne | Wallmann-Sperlich B.,German Sport University Cologne | And 2 more authors.
Journal of Physical Activity and Health | Year: 2015

Background: Inactivity and overweight are major health concerns in children and adolescents with disabilities. Methods for the assessment of activity and energy expenditure may be affected negatively by the underlying disability, especially when motor function is impaired. The purpose of this study was to assess the validity of the SenseWear Armband in adolescents with cerebral palsy and hemiparesis. Methods: Ten volunteers (age: 13.4 ± 1.6 years) were equipped with SenseWear Armbands on the hemiparetic and nonhemiparetic side of the body. Energy expenditure was measured at rest and during treadmill exercise (speed range: 0.85 to 2.35 m/s). Indirect calorimetry served as independent reference method. Results: The mean error was between -0.6 and 0.8 kcal/min and there were no significant differences between SenseWear and indirect calorimetry at any speed. Differences between body sides in expenditure (mean: -0.2 to 0.0 kcal/min) and step count (mean: -3.4 to 9.7 steps/min) were not significant. Conclusions: The validity of the SenseWear Armband does not appear to be negatively affected by cerebral palsy during laboratory treadmill exercise. Future field studies are necessary to assess the validity and practicability of energy expenditure and physical activity assessment in children and adolescents with physical disabilities. © 2015 Human Kinetics, Inc. Source


Chaudhuri S.,Pensylvania State University | Solar-Lezama A.,Massachusetts Institute of Technology
Proceedings of the ACM SIGPLAN Conference on Programming Language Design and Implementation (PLDI) | Year: 2010

We present smooth interpretation, a method to systematically approximate numerical imperative programs by smooth mathematical functions. This approximation facilitates the use of numerical search techniques like gradient descent for program analysis and synthesis. The method extends to programs the notion of Gaussian smoothing, a popular signal-processing technique that filters out noise and discontinuities from a signal by taking its convolution with a Gaussian function. In our setting, Gaussian smoothing executes a program according to a probabilistic semantics; the execution of program P on an input x after Gaussian smoothing can be summarized as follows: (1) Apply a Gaussian perturbation to x - the perturbed input is a random variable following a normal distribution with mean x. (2) Compute and return the expected output of P on this perturbed input. Computing the expectation explicitly would require the execution of P on all possible inputs, but smooth interpretation bypasses this requirement by using a form of symbolic execution to approximate the effect of Gaussian smoothing on P. The result is an efficient but approximate implementation of Gaussian smoothing of programs. Smooth interpretation has the effect of attenuating features of a program that impede numerical searches of its input space - for example, discontinuities resulting from conditional branches are replaced by continuous transitions. We apply smooth interpretation to the problem of synthesizing values of numerical control parameters in embedded control applications. This problem is naturally formulated as one of numerical optimization: the goal is to find parameter values that minimize the error between the resulting program and a programmer-provided behavioral specification. Solving this problem by directly applying numerical optimization techniques is often impractical due to the discontinuities in the error function. By eliminating these discontinuities, smooth interpretation makes it possible to search the parameter space efficiently by means of simple gradient descent. Our experiments demonstrate the value of this strategy in synthesizing parameters for several challenging programs, including models of an automated gear shift and a PID controller. © 2010 ACM. Source


D'Avanzo P.,National institute for astrophysics | Perri M.,Science Data Center | Fugazza D.,National institute for astrophysics | Salvaterra R.,University of Insubria | And 22 more authors.
Astronomy and Astrophysics | Year: 2010

Context. Gamma-ray bursts (GRBs) have proven to be detectable to distances much larger than any other astrophysical object, providing the most effective way, complementing ordinary surveys of studying the high redshift universe. Aims. We present the results of an observational campaign devoted to the study of the high-z GRB 090205. Methods. We carried out optical/NIR spectroscopy and imaging of GRB 090205 with the ESO-VLT starting from hours after the event to several days later to detect the host galaxy. We compared the results obtained from our optical/NIR observations with the available Swift high-energy data of this burst. Results. Our observational campaign led to the detection of the optical afterglow and host galaxy of GRB 090205 and to the first measure of its redshift, z = 4.65. As in other high-z GRBs, GRB 090205 has a short duration in the rest frame with T90,rf = 1.6 s, which suggests that it might belong to the short GRB class. The X-ray afterglow of GRB 090205 has a complex and interesting behavior with a possible rebrightening at 500-1000 s from the trigger time and late flaring activity. Photometric observations of the GRB 090205 host galaxy imply that it is a starburst galaxy with a stellar population younger than ∼150 Myr. Moreover, the metallicity of Z > 0.27 ⊙ derived from the GRB afterglow spectrum is among the highest derived from GRB afterglow measurement at high-z, suggesting that the burst occurred in a rather enriched environment. Finally, a detailed analysis of the afterglow spectrum shows the existence of a line corresponding to Lyman-α emission at the redshift of the burst. GRB 090205 is thus hosted by a typical Lyman-α emitter (LAE) at z = 4.65. This makes the host galaxy of GRB 090205 the farthest GRB host galaxy, spectroscopically confirmed, detected to date. © 2010 ESO. Source


Williams A.,University of Miami | Rawal S.,University of Miami | Ao Z.,University of Miami | Torres-Munoz J.,University of Miami | And 6 more authors.
IEEE EMBS Special Topic Conference on Point-of-Care (POC) Healthcare Technologies: Synergy Towards Better Global Healthcare, PHT 2013 | Year: 2013

The most important determinant of prognosis and management of cancer is the presence or absence of metastasis [1]. The road to metastasis involves tumor cells to become detached from the primary tumor and travel in the blood to distant sites, causing secondary tumors. These tumor cells traveling in blood are termed Circulating tumor cells (CTC). Capture of CTC from whole blood has been a challenging feat. The fact that these CTC are few in number, to effectively and efficiently isolate them from whole blood can be thought of as looking for a needle in a haystack. Our microfilter technology exploits the use of size based capture of the larger CTC from the smaller white blood cells and components of whole blood. The effective capture potential of the microfilter platform has driven the area of CTC analysis into a new age of research in the field of cancer. The ability to finally analyze CTC at a molecular level, leads to a deeper understanding of metastatic process, while providing an opportunity to evaluate, monitor and manage treatment options as well as the adherent possibility of having an "on-chip" drug sensitivity assay for focused treatment options. We have demonstrated through clinical trials the ability to effectively identify, enumerate and characterize CTC based on immunfluorescence and FISH assays and provide a companion endpoint for monitoring and evaluating treatment management. Our work on viable CTC capture has resulted in successfully capturing and culturing CTC from blood in mouse models that have been inoculated with breast cancer cell lines to form primary and secondary metastatic cancer sites. The future potential within the microfilter technology to capture viable CTC for culture, will catapult therapeutic interventions to a new level of personalized medicine in cancer management. © 2013 IEEE. Source

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