Science.gov

Sample records for problemes sanitaires poses

  1. Student-Posed Problems

    NASA Astrophysics Data System (ADS)

    Harper, Kathleen A.; Etkina, Eugenia

    2002-10-01

    As part of weekly reports,1 structured journals in which students answer three standard questions each week, they respond to the prompt, If I were the instructor, what questions would I ask or problems assign to determine if my students understood the material? An initial analysis of the results shows that some student-generated problems indicate fundamental misunderstandings of basic physical concepts. A further investigation explores the relevance of the problems to the week's material, whether the problems are solvable, and the type of problems (conceptual or calculation-based) written. Also, possible links between various characteristics of the problems and conceptual achievement are being explored. The results of this study spark many more questions for further work. A summary of current findings will be presented, along with its relationship to previous work concerning problem posing.2 1Etkina, E. Weekly Reports;A Two-Way Feedback Tool, Science Education, 84, 594-605 (2000). 2Mestre, J.P., Probing Adults Conceptual Understanding and Transfer of Learning Via Problem Posing, Journal of Applied Developmental Psychology, 23, 9-50 (2002).

  2. Problem Posing and Solving with Mathematical Modeling

    ERIC Educational Resources Information Center

    English, Lyn D.; Fox, Jillian L.; Watters, James J.

    2005-01-01

    Mathematical modeling is explored as both problem posing and problem solving from two perspectives, that of the child and the teacher. Mathematical modeling provides rich learning experiences for elementary school children and their teachers.

  3. Numerical Regularization of Ill-Posed Problems.

    DTIC Science & Technology

    1980-07-09

    Unione Matematica Italiana. 4. The parameter choice problem in linear regularization: a mathematical introduction, in "Ill-Posed Problems: Theory and...vector b which is generally unavailable (see [21], [22]). Kdckler [33] has shon however that in the case of Tikhonov regularization for matrices it may

  4. Pose and Solve Varignon Converse Problems

    ERIC Educational Resources Information Center

    Contreras, José N.

    2014-01-01

    The activity of posing and solving problems can enrich learners' mathematical experiences because it fosters a spirit of inquisitiveness, cultivates their mathematical curiosity, and deepens their views of what it means to do mathematics. To achieve these goals, a mathematical problem needs to be at the appropriate level of difficulty,…

  5. Quadratic optimization in ill-posed problems

    NASA Astrophysics Data System (ADS)

    Ben Belgacem, F.; Kaber, S.-M.

    2008-10-01

    Ill-posed quadratic optimization frequently occurs in control and inverse problems and is not covered by the Lax-Milgram-Riesz theory. Typically, small changes in the input data can produce very large oscillations on the output. We investigate the conditions under which the minimum value of the cost function is finite and we explore the 'hidden connection' between the optimization problem and the least-squares method. Eventually, we address some examples coming from optimal control and data completion, showing how relevant our contribution is in the knowledge of what happens for various ill-posed problems. The results we state bring a substantial improvement to the analysis of the regularization methods applied to the ill-posed quadratic optimization problems. Indeed, for the cost quadratic functions bounded from below the Lavrentiev method is just the Tikhonov regularization for the 'hidden least-squares' problem. As a straightforward result, Lavrentiev's regularization exhibits better regularization and convergence results than expected at first glance.

  6. Pre-Service Teachers' Free and Structured Mathematical Problem Posing

    ERIC Educational Resources Information Center

    Silber, Steven; Cai, Jinfa

    2017-01-01

    This exploratory study examined how pre-service teachers (PSTs) pose mathematical problems for free and structured mathematical problem-posing conditions. It was hypothesized that PSTs would pose more complex mathematical problems under structured posing conditions, with increasing levels of complexity, than PSTs would pose under free posing…

  7. Skill Levels of Prospective Physics Teachers on Problem Posing

    ERIC Educational Resources Information Center

    Cildir, Sema; Sezen, Nazan

    2011-01-01

    Problem posing is one of the topics which the educators thoroughly accentuate. Problem posing skill is defined as an introvert activity of a student's learning. In this study, skill levels of prospective physics teachers on problem posing were determined and their views on problem posing were evaluated. To this end, prospective teachers were given…

  8. Artifacts as Sources for Problem-Posing Activities

    ERIC Educational Resources Information Center

    Bonotto, Cinzia

    2013-01-01

    The problem-posing process represents one of the forms of authentic mathematical inquiry which, if suitably implemented in classroom activities, could move well beyond the limitations of word problems, at least as they are typically utilized. The two exploratory studies presented sought to investigate the impact of "problem-posing" activities when…

  9. The Posing of Arithmetic Problems by Mathematically Talented Students

    ERIC Educational Resources Information Center

    Espinoza González, Johan; Lupiáñez Gómez, José Luis; Segovia Alex, Isidoro

    2016-01-01

    Introduction: This paper analyzes the arithmetic problems posed by a group of mathematically talented students when given two problem-posing tasks, and compares these students' responses to those given by a standard group of public school students to the same tasks. Our analysis focuses on characterizing and identifying the differences between the…

  10. Embedding Game-Based Problem-Solving Phase into Problem-Posing System for Mathematics Learning

    ERIC Educational Resources Information Center

    Chang, Kuo-En; Wu, Lin-Jung; Weng, Sheng-En; Sung, Yao-Ting

    2012-01-01

    A problem-posing system is developed with four phases including posing problem, planning, solving problem, and looking back, in which the "solving problem" phase is implemented by game-scenarios. The system supports elementary students in the process of problem-posing, allowing them to fully engage in mathematical activities. In total, 92 fifth…

  11. Investigation of Problem-Solving and Problem-Posing Abilities of Seventh-Grade Students

    ERIC Educational Resources Information Center

    Arikan, Elif Esra; Ünal, Hasan

    2015-01-01

    This study aims to examine the effect of multiple problem-solving skills on the problem-posing abilities of gifted and non-gifted students and to assess whether the possession of such skills can predict giftedness or affect problem-posing abilities. Participants' metaphorical images of problem posing were also explored. Participants were 20 gifted…

  12. Using Problem-Posing Dialogue in Adult Literacy Education.

    ERIC Educational Resources Information Center

    Nixon-Ponder, Sarah

    1995-01-01

    Problem-posing is a tool for developing and strengthening critical thinking skills. It is an inductive questioning process that structures dialog in the classroom. Five steps include describing the content, defining the problem, personalizing it, discussing it, and discussing alternatives. (Author/JOW)

  13. Mathematical Thinking and Creativity through Mathematical Problem Posing and Solving

    ERIC Educational Resources Information Center

    Ayllón, María F.; Gómez, Isabel A.; Ballesta-Claver, Julio

    2016-01-01

    This work shows the relationship between the development of mathematical thinking and creativity with mathematical problem posing and solving. Creativity and mathematics are disciplines that do not usually appear together. Both concepts constitute complex processes sharing elements, such as fluency (number of ideas), flexibility (range of ideas),…

  14. Using Problem-Posing Dialogue in Adult Literacy Education. Teacher to Teacher.

    ERIC Educational Resources Information Center

    Nixon-Ponder, Sarah

    Problem posing is a tool for developing and strengthening critical thinking skills. Freire expanded on the idea of active, participatory education through problem-posing dialogue, a method that transforms the students into critical coinvestigators in dialogue with the teacher. Problem posing begins by listening for students' issues. Teachers…

  15. The Analysis of the Problems the Pre-Service Teachers Experience in Posing Problems about Equations

    ERIC Educational Resources Information Center

    Isik, Cemalettin; Kar, Tugrul

    2012-01-01

    The present study aimed to analyse the potential difficulties in the problems posed by pre-service teachers about first degree equations with one unknown and equation pairs with two unknowns. It was carried out with 20 pre-service teachers studying in the Department of Elementary Mathematics Educations at a university in Eastern Turkey. The…

  16. Testing a Comprehensive Model for Measuring Problem Solving and Problem Posing Skills of Primary Pupils

    ERIC Educational Resources Information Center

    Charalambous, Charalambos; Kyriakides, Leonidas; Philippou, George

    2003-01-01

    The study reported in this paper is an attempt to develop a comprehensive model of measuring problem solving and posing (PSP) skills based on Marshall's schema theory (ST). A battery of tests on PSP skills was administered to 5th and 6th grade Cypriot students (n=2519). The Rasch model was used and a scale was created for the battery of tests and…

  17. Analyzing Pre-Service Primary Teachers' Fraction Knowledge Structures through Problem Posing

    ERIC Educational Resources Information Center

    Kilic, Cigdem

    2015-01-01

    In this study it was aimed to determine pre-service primary teachers' knowledge structures of fraction through problem posing activities. A total of 90 pre-service primary teachers participated in this study. A problem posing test consisting of two questions was used and the participants were asked to generate as many as problems based on the…

  18. A well posed boundary value problem in transonic gas dynamics

    NASA Technical Reports Server (NTRS)

    Sanz, J. M.

    1978-01-01

    A boundary value problem for the Tricomi equation was studied in connection with transonic gas dynamics. The transformed equation delta u plus 1/3Y u sub Y equals 0 in canonical coordinates was considered in the complex domain of two independent complex variables. A boundary value problem was then set by prescribing the real part of the solution on the boundary of the real unit circle. The Dirichlet problem in the upper unit semicircle with vanishing values of the solution at Y = 0 was solved explicitly in terms of the hypergeometric function for the more general Euler-Poisson-Darboux equation. An explicit representation of the solution was also given for a mixed Dirichlet and Neumann problem for the same equation and domain.

  19. Teachers Implementing Mathematical Problem Posing in the Classroom: Challenges and Strategies

    ERIC Educational Resources Information Center

    Leung, Shuk-kwan S.

    2013-01-01

    This paper reports a study about how a teacher educator shared knowledge with teachers when they worked together to implement mathematical problem posing (MPP) in the classroom. It includes feasible methods for getting practitioners to use research-based tasks aligned to the curriculum in order to encourage children to pose mathematical problems.…

  20. Prospective Middle School Mathematics Teachers' Knowledge of Linear Graphs in Context of Problem-Posing

    ERIC Educational Resources Information Center

    Kar, Tugrul

    2016-01-01

    This study examined prospective middle school mathematics teachers' problem-posing skills by investigating their ability to associate linear graphs with daily life situations. Prospective teachers were given linear graphs and asked to pose problems that could potentially be represented by the graphs. Their answers were analyzed in two stages. In…

  1. The Effects of Problem Posing on Student Mathematical Learning: A Meta-Analysis

    ERIC Educational Resources Information Center

    Rosli, Roslinda; Capraro, Mary Margaret; Capraro, Robert M.

    2014-01-01

    The purpose of the study was to meta-synthesize research findings on the effectiveness of problem posing and to investigate the factors that might affect the incorporation of problem posing in the teaching and learning of mathematics. The eligibility criteria for inclusion of literature in the meta-analysis was: published between 1989 and 2011,…

  2. An Investigation of Eighth Grade Students' Problem Posing Skills (Turkey Sample)

    ERIC Educational Resources Information Center

    Arikan, Elif Esra; Ünal, Hasan

    2015-01-01

    To pose a problem refers to the creative activity for mathematics education. The purpose of the study was to explore the eighth grade students' problem posing ability. Three learning domains such as requiring four operations, fractions and geometry were chosen for this reason. There were two classes which were coded as class A and class B. Class A…

  3. Problem-Posing Research in Mathematics Education: Looking Back, Looking Around, and Looking Ahead

    ERIC Educational Resources Information Center

    Silver, Edward A.

    2013-01-01

    In this paper, I comment on the set of papers in this special issue on mathematical problem posing. I offer some observations about the papers in relation to several key issues, and I suggest some productive directions for continued research inquiry on mathematical problem posing.

  4. Critical Inquiry across the Disciplines: Strategies for Student-Generated Problem Posing

    ERIC Educational Resources Information Center

    Nardone, Carroll Ferguson; Lee, Renee Gravois

    2011-01-01

    Problem posing is a higher-order, active-learning task that is important for students to develop. This article describes a series of interdisciplinary learning activities designed to help students strengthen their problem-posing skills, which requires that students become more responsible for their learning and that faculty move to a facilitator…

  5. An Investigation of Relationships between Students' Mathematical Problem-Posing Abilities and Their Mathematical Content Knowledge

    ERIC Educational Resources Information Center

    Van Harpen, Xianwei Y.; Presmeg, Norma C.

    2013-01-01

    The importance of students' problem-posing abilities in mathematics has been emphasized in the K-12 curricula in the USA and China. There are claims that problem-posing activities are helpful in developing creative approaches to mathematics. At the same time, there are also claims that students' mathematical content knowledge could be highly…

  6. Inflammatory bowel disease in adolescents: What problems does it pose?

    PubMed Central

    Lu, Ying; Markowitz, James

    2011-01-01

    Adolescents with inflammatory bowel disease face daily and long-term challenges that may be difficult for teenagers to manage. The developmental and psychosocial changes unique to this age group include becoming more autonomous and being more vulnerable to peer influence. These changes may lead to problems in medical management such as poor medication adherence and risky behavior. Being aware of these issues will help the medical team provide anticipatory guidance to address these concerns. PMID:21734775

  7. The Relationship between Students' Problem Posing and Problem Solving Abilities and Beliefs: A Small-Scale Study with Chinese Elementary School Children

    ERIC Educational Resources Information Center

    Limin, Chen; Van Dooren, Wim; Verschaffel, Lieven

    2013-01-01

    The goal of the present study is to investigate the relationship between pupils' problem posing and problem solving abilities, their beliefs about problem posing and problem solving, and their general mathematics abilities, in a Chinese context. Five instruments, i.e., a problem posing test, a problem solving test, a problem posing questionnaire,…

  8. The residual method for regularizing ill-posed problems

    PubMed Central

    Grasmair, Markus; Haltmeier, Markus; Scherzer, Otmar

    2011-01-01

    Although the residual method, or constrained regularization, is frequently used in applications, a detailed study of its properties is still missing. This sharply contrasts the progress of the theory of Tikhonov regularization, where a series of new results for regularization in Banach spaces has been published in the recent years. The present paper intends to bridge the gap between the existing theories as far as possible. We develop a stability and convergence theory for the residual method in general topological spaces. In addition, we prove convergence rates in terms of (generalized) Bregman distances, which can also be applied to non-convex regularization functionals. We provide three examples that show the applicability of our theory. The first example is the regularized solution of linear operator equations on Lp-spaces, where we show that the results of Tikhonov regularization generalize unchanged to the residual method. As a second example, we consider the problem of density estimation from a finite number of sampling points, using the Wasserstein distance as a fidelity term and an entropy measure as regularization term. It is shown that the densities obtained in this way depend continuously on the location of the sampled points and that the underlying density can be recovered as the number of sampling points tends to infinity. Finally, we apply our theory to compressed sensing. Here, we show the well-posedness of the method and derive convergence rates both for convex and non-convex regularization under rather weak conditions. PMID:22345828

  9. Ill Posed Problems: Numerical and Statistical Methods for Mildly, Moderately and Severely Ill Posed Problems with Noisy Data.

    DTIC Science & Technology

    1980-02-01

    vector z about the function f if there were no errors in the data and K is known perfectly. Examination of the intrinsic rank of a problem can provide...matrix of the representers of the data functionals . If H =L 2CO,lJ, then =-I 9T1 k> rjs (s )ds KtjsKKsd, and, if qH RO then <r11 =0 ffK(tj~s)R( s,t)K...for wnich k i/\\I > SZI0 "l (computer roundoff). Thus rI is the effective number of linearly independent data functionals in the experiment (1.1) in

  10. A well-posed optimal spectral element approximation for the Stokes problem

    NASA Technical Reports Server (NTRS)

    Maday, Y.; Patera, A. T.; Ronquist, E. M.

    1987-01-01

    A method is proposed for the spectral element simulation of incompressible flow. This method constitutes in a well-posed optimal approximation of the steady Stokes problem with no spurious modes in the pressure. The resulting method is analyzed, and numerical results are presented for a model problem.

  11. Assessment of a Problem Posing Task in a Jamaican Grade Four Mathematics Classroom

    ERIC Educational Resources Information Center

    Munroe, Kayan Lloyd

    2016-01-01

    This paper analyzes how a teacher of mathematics used problem posing in the assessment of the cognitive development of 26 students at the grade-four level. The students, ages 8 to 10 years, were from a rural elementary school in western Jamaica. Using a picture as a prompt, students were asked to generate three arithmetic problems and to offer…

  12. Investigating the Impact of Field Trips on Teachers' Mathematical Problem Posing

    ERIC Educational Resources Information Center

    Courtney, Scott A.; Caniglia, Joanne; Singh, Rashmi

    2014-01-01

    This study examines the impact of field trip experiences on teachers' mathematical problem posing. Teachers from a large urban public school system in the Midwest participated in a professional development program that incorporated experiential learning with mathematical problem formulation experiences. During 2 weeks of summer 2011, 68 teachers…

  13. Well-posed ADM equivalent of the Bondi-Sachs problem

    SciTech Connect

    Frittelli, Simonetta

    2006-06-15

    Every well-posed hyperbolic problem has an associated characteristic representation. In the case of the Einstein equations, traditionally, characteristic problems have been stated in the Bondi-Sachs form, whereas initial-value problems have been represented in the ADM form, both being looked upon as independent versions of the Einstein equations. Under the restriction of spherical symmetry, we provide an ADM version of the Einstein equations that functions as the initial-value representation of the Bondi-Sachs equations. The ADM version allows us to interpret the Bondi-Sachs variables precisely in terms of characteristic fields of the Cauchy problem. The Bondi-Sachs version thus leads us to a version of the Cauchy problem that is first order in time (with no need for reduction) and automatically well posed.

  14. Cultural and Political Vignettes in the English Classroom: Problem-Posing, Problem-Solving, and the Imagination

    ERIC Educational Resources Information Center

    Darvin, Jacqueline

    2009-01-01

    One way to merge imagination with problem-posing and problem-solving in the English classroom is by asking students to respond to "cultural and political vignettes" (CPVs). CPVs are cultural and political situations that are presented to students so that they can practice the creative and essential decision-making skills that they will need to use…

  15. An Error Analysis in Division Problems in Fractions Posed by Pre-Service Elementary Mathematics Teachers

    ERIC Educational Resources Information Center

    Isik, Cemalettin; Kar, Tugrul

    2012-01-01

    The present study aimed to make an error analysis in the problems posed by pre-service elementary mathematics teachers about fractional division operation. It was carried out with 64 pre-service teachers studying in their final year in the Department of Mathematics Teaching in an eastern university during the spring semester of academic year…

  16. Development of a Mobile Learning System Based on a Collaborative Problem-Posing Strategy

    ERIC Educational Resources Information Center

    Sung, Han-Yu; Hwang, Gwo-Jen; Chang, Ya-Chi

    2016-01-01

    In this study, a problem-posing strategy is proposed for supporting collaborative mobile learning activities. Accordingly, a mobile learning environment has been developed, and an experiment on a local culture course has been conducted to evaluate the effectiveness of the proposed approach. Three classes of an elementary school in southern Taiwan…

  17. The World in a Tomato: Revisiting the Use of "Codes" in Freire's Problem-Posing Education.

    ERIC Educational Resources Information Center

    Barndt, Deborah

    1998-01-01

    Gives examples of the use of Freire's notion of codes or generative themes in problem-posing literacy education. Describes how these applications expand Freire's conceptions by involving students in code production, including multicultural perspectives, and rethinking codes as representations. (SK)

  18. Group-sparsity regularization for ill-posed subsurface flow inverse problems

    NASA Astrophysics Data System (ADS)

    Golmohammadi, Azarang; Khaninezhad, Mohammad-Reza M.; Jafarpour, Behnam

    2015-10-01

    Sparse representations provide a flexible and parsimonious description of high-dimensional model parameters for reconstructing subsurface flow property distributions from limited data. To further constrain ill-posed inverse problems, group-sparsity regularization can take advantage of possible relations among the entries of unknown sparse parameters when: (i) groups of sparse elements are either collectively active or inactive and (ii) only a small subset of the groups is needed to approximate the parameters of interest. Since subsurface properties exhibit strong spatial connectivity patterns they may lead to sparse descriptions that satisfy the above conditions. When these conditions are established, a group-sparsity regularization can be invoked to facilitate the solution of the resulting inverse problem by promoting sparsity across the groups. The proposed regularization penalizes the number of groups that are active without promoting sparsity within each group. Two implementations are presented in this paper: one based on the multiresolution tree structure of Wavelet decomposition, without a need for explicit prior models, and another learned from explicit prior model realizations using sparse principal component analysis (SPCA). In each case, the approach first classifies the parameters of the inverse problem into groups with specific connectivity features, and then takes advantage of the grouped structure to recover the relevant patterns in the solution from the flow data. Several numerical experiments are presented to demonstrate the advantages of additional constraining power of group-sparsity in solving ill-posed subsurface model calibration problems.

  19. Quelques problemes poses a la grammaire casuelle (Some Problems Regarding Case Grammar)

    ERIC Educational Resources Information Center

    Fillmore, Charles J.

    1975-01-01

    Discusses problems related to case grammar theory, including: the organizations of a case grammar; determination of semantic roles; definition and hierarchy of cases; cause-effect relations; and formalization and notation. (Text is in French.) (AM)

  20. A problem-posing approach to teaching the topic of radioactivity

    NASA Astrophysics Data System (ADS)

    Klaassen, C. W. J. M.

    1995-12-01

    This thesis highlights a problem-posing approach to science education. By this is meant an approach that explicitly aims at providing students with content-related motives for extending their existing conceptual resources, experiential base and belief system in a certain direction, such that a further development in that direction eventually leads to a proper understanding of science. An elaboration of that approach consists in designing, testing, improving, etc, concrete didactical structures. The eventual aim of the approach is a coherent, and by means of developmental research empirically supported, didactical structure that covers the whole of science education. The thesis also contains a few steps in the direction suggested by this programmatic view. It contains an illustration of the heuristic value of an articulation of a didactical structure in some main substructures, based on the work of van Hiele and ten Voorde. It further contains a discussion of some methodological aspects relating to the design and evaluation of a didactical structure, and of the role that a further developed version of Davidson's theory of interpretation could play in this respect. A detailed didactical structure of the topic of radioactivity is presented, evaluated and, on the basis of the evaluation, judged as `good enough.' Also the role of the teacher in a problem-posing approach is dis-cussed, and in particular the consequences for that role of giving students control over and responsibility for the progress of their learning process with respect to content.

  1. Ill-posed problem and regularization in reconstruction of radiobiological parameters from serial tumor imaging data

    NASA Astrophysics Data System (ADS)

    Chvetsov, Alevei V.; Sandison, George A.; Schwartz, Jeffrey L.; Rengan, Ramesh

    2015-11-01

    The main objective of this article is to improve the stability of reconstruction algorithms for estimation of radiobiological parameters using serial tumor imaging data acquired during radiation therapy. Serial images of tumor response to radiation therapy represent a complex summation of several exponential processes as treatment induced cell inactivation, tumor growth rates, and the rate of cell loss. Accurate assessment of treatment response would require separation of these processes because they define radiobiological determinants of treatment response and, correspondingly, tumor control probability. However, the estimation of radiobiological parameters using imaging data can be considered an inverse ill-posed problem because a sum of several exponentials would produce the Fredholm integral equation of the first kind which is ill posed. Therefore, the stability of reconstruction of radiobiological parameters presents a problem even for the simplest models of tumor response. To study stability of the parameter reconstruction problem, we used a set of serial CT imaging data for head and neck cancer and a simplest case of a two-level cell population model of tumor response. Inverse reconstruction was performed using a simulated annealing algorithm to minimize a least squared objective function. Results show that the reconstructed values of cell surviving fractions and cell doubling time exhibit significant nonphysical fluctuations if no stabilization algorithms are applied. However, after applying a stabilization algorithm based on variational regularization, the reconstruction produces statistical distributions for survival fractions and doubling time that are comparable to published in vitro data. This algorithm is an advance over our previous work where only cell surviving fractions were reconstructed. We conclude that variational regularization allows for an increase in the number of free parameters in our model which enables development of more

  2. Calibrating corneal material model parameters using only inflation data: an ill-posed problem.

    PubMed

    Kok, S; Botha, N; Inglis, H M

    2014-12-01

    Goldmann applanation tonometry (GAT) is a method used to estimate the intraocular pressure by measuring the indentation resistance of the cornea. A popular approach to investigate the sensitivity of GAT results to material and geometry variations is to perform numerical modelling using the finite element method, for which a calibrated material model is required. These material models are typically calibrated using experimental inflation data by solving an inverse problem. In the inverse problem, the underlying material constitutive behaviour is inferred from the measured macroscopic response (chamber pressure versus apical displacement). In this study, a biomechanically motivated elastic fibre-reinforced corneal material model is chosen. The inverse problem of calibrating the corneal material model parameters using only experimental inflation data is demonstrated to be ill-posed, with small variations in the experimental data leading to large differences in the calibrated model parameters. This can result in different groups of researchers, calibrating their material model with the same inflation test data, drawing vastly different conclusions about the effect of material parameters on GAT results. It is further demonstrated that multiple loading scenarios, such as inflation as well as bending, would be required to reliably calibrate such a corneal material model.

  3. High-School Students' Approaches to Solving Algebra Problems that Are Posed Symbolically: Results from an Interview Study

    ERIC Educational Resources Information Center

    Huntley, Mary Ann; Davis, Jon D.

    2008-01-01

    A cross-curricular structured-probe task-based clinical interview study with 44 pairs of third year high-school mathematics students, most of whom were high achieving, was conducted to investigate their approaches to a variety of algebra problems. This paper presents results from three problems that were posed in symbolic form. Two problems are…

  4. Sparse deconvolution for the large-scale ill-posed inverse problem of impact force reconstruction

    NASA Astrophysics Data System (ADS)

    Qiao, Baijie; Zhang, Xingwu; Gao, Jiawei; Liu, Ruonan; Chen, Xuefeng

    2017-01-01

    Most previous regularization methods for solving the inverse problem of force reconstruction are to minimize the l2-norm of the desired force. However, these traditional regularization methods such as Tikhonov regularization and truncated singular value decomposition, commonly fail to solve the large-scale ill-posed inverse problem in moderate computational cost. In this paper, taking into account the sparse characteristic of impact force, the idea of sparse deconvolution is first introduced to the field of impact force reconstruction and a general sparse deconvolution model of impact force is constructed. Second, a novel impact force reconstruction method based on the primal-dual interior point method (PDIPM) is proposed to solve such a large-scale sparse deconvolution model, where minimizing the l2-norm is replaced by minimizing the l1-norm. Meanwhile, the preconditioned conjugate gradient algorithm is used to compute the search direction of PDIPM with high computational efficiency. Finally, two experiments including the small-scale or medium-scale single impact force reconstruction and the relatively large-scale consecutive impact force reconstruction are conducted on a composite wind turbine blade and a shell structure to illustrate the advantage of PDIPM. Compared with Tikhonov regularization, PDIPM is more efficient, accurate and robust whether in the single impact force reconstruction or in the consecutive impact force reconstruction.

  5. Ways of Thinking Associated with Mathematics Teachers' Problem Posing in the Context of Division of Fractions

    ERIC Educational Resources Information Center

    Koichu, Boris; Harel, Guershon; Manaster, Alfred

    2013-01-01

    Twenty-four mathematics teachers were asked to think aloud when posing a word problem whose solution could be found by computing 4/5 divided by 2/3. The data consisted of verbal protocols along with the written notes made by the subjects. The qualitative analysis of the data was focused on identifying the structures of the problems produced and…

  6. Engaging Pre-Service Middle-School Teacher-Education Students in Mathematical Problem Posing: Development of an Active Learning Framework

    ERIC Educational Resources Information Center

    Ellerton, Nerida F.

    2013-01-01

    Although official curriculum documents make cursory mention of the need for problem posing in school mathematics, problem posing rarely becomes part of the implemented or assessed curriculum. This paper provides examples of how problem posing can be made an integral part of mathematics teacher education programs. It is argued that such programs…

  7. Analysis of Problems Posed by Sixth-Grade Middle School Students for the Addition of Fractions in Terms of Semantic Structures

    ERIC Educational Resources Information Center

    Kar, Tugrul

    2015-01-01

    This study aimed to investigate how the semantic structures of problems posed by sixth-grade middle school students for the addition of fractions affect their problem-posing performance. The students were presented with symbolic operations involving the addition of fractions and asked to pose two different problems related to daily-life situations…

  8. The Numerical Inversion of the Laplace Transform in Reproducing Kernel Hilbert Spaces for Ill-Posed Problems

    ERIC Educational Resources Information Center

    Iqbal, M.

    2002-01-01

    In this paper we have converted the Laplace transform into an integral equation of the first kind of convolution type, which is an ill-posed problem, and used a statistical regularization method to solve it. The method is applied to three examples. It gives a good approximation to the true solution and compares well with the method given by…

  9. Well-Posed Stokes/Brinkman and Stokes/Darcy Problems for Coupled Fluid-Porous Viscous Flows

    NASA Astrophysics Data System (ADS)

    Angot, Philippe

    2010-09-01

    We present a well-posed model for the Stokes/Brinkman problem with a family of jump embedded boundary conditions (J.E.B.C.) on an immersed interface with weak regularity assumptions. It is issued from a general framework recently proposed for fictitious domain problems. Our model is based on algebraic transmission conditions combining the stress and velocity jumps on the interface Σ separating the fluid and porous domains. These conditions, well chosen to get the coercivity of the operator, are sufficiently general to get the usual immersed boundary conditions on Σ when fictitious domain methods are concerned: Stefan-like, Robin (Fourier), Neumann or Dirichlet… Moreover, the general framework allows to prove the global solvability of some models with physically relevant stress or velocity jump boundary conditions for the momentum transport at a fluid-porous interface. The Stokes/Brinkman problem with Ochoa-Tapia & Whitaker (1995) interface conditions and the Stokes/Darcy problem with Beavers & Joseph (1967) conditions are both proved to be well-posed by an asymptotic analysis. Up to our knowledge, only the Stokes/Darcy problem with Saffman (1971) approximate interface conditions was known to be well-posed.

  10. Analysis of problems posed by sixth-grade middle school students for the addition of fractions in terms of semantic structures

    NASA Astrophysics Data System (ADS)

    Kar, Tuğrul

    2015-08-01

    This study aimed to investigate how the semantic structures of problems posed by sixth-grade middle school students for the addition of fractions affect their problem-posing performance. The students were presented with symbolic operations involving the addition of fractions and asked to pose two different problems related to daily-life situations for each item, which could only be solved using the given operations. The problems posed were analyzed in terms of their semantic structures and conceptual validity. The results of the study showed that students who posed problems using the two different structures 'part-part-whole' and 'join' demonstrated higher performance in problem posing. The performance of the students using only one category - join or part-part-whole - was lower, with the latter being the lowest.

  11. C-type cytochromes: diverse structures and biogenesis systems pose evolutionary problems.

    PubMed Central

    Allen, James W A; Daltrop, Oliver; Stevens, Julie M; Ferguson, Stuart J

    2003-01-01

    C-type cytochromes are a structurally diverse group of haemoproteins, which are related by the occurrence of haem covalently attached to a polypeptide via two thioether bonds formed by the vinyl groups of haem and cysteine side chains in a CXXCH peptide motif. Remarkably, three different post-translational systems for forming these cytochromes have been identified. The evolution of both the proteins themselves and the biogenesis systems poses many questions to which answers are currently being sought. In this article we review the progress that has been made in understanding the need for covalent attachment of haem to proteins in cytochromes c and the complex systems involved in their formation. PMID:12594933

  12. Is the forward problem of ground water hydrology always well posed?

    PubMed

    Valota, Giorgio; Giudici, Mauro; Parravicini, Guido; Ponzini, Giansilvio; Romano, Emanuele

    2002-01-01

    Complex aquifer systems are often modeled with quasi-three-dimensional models, which consider two-dimensional horizontal flow in the aquifers and one-dimensional vertical flow through aquitards. When the aquifer system consists of a phreatic aquifer and one or more semiconfined aquifers connected by aquitards, the discrete model consists of a nonlinear system of algebraic equations, because the transmissivity of the phreatic aquifer depends on the phreatic head. If the water extraction is very high, the phreatic aquifer can be depleted and the equations of the model must be modified accordingly. There are not simple and general criteria to state if the phreatic aquifer is depleted before solving the system of equations. Therefore, the iterative procedures (e.g., relaxation methods), used to find the solution to the forward problem, must handle these particular conditions and can suffer several problems of convergence. These problems can be caused by the choice of the initial head values or of the relaxation coefficient of the iterative algorithms; however, they can also be caused by the nonexistence or nonuniqueness of the solution to the system of nonlinear equations. The study of existence and uniqueness of the general problem is very difficult and, therefore, we consider a simplified problem, for which the discrete model can be handled analytically. The results of the numerical experiments show that the solution to the forward problem can be nonunique. Only for some cases it is possible to invoke physical arguments to eliminate tentative solutions.

  13. Language and Culture in Conflict. Problem-Posing in the ESL Classroom.

    ERIC Educational Resources Information Center

    Wallerstein, Nina

    This book grew out of an actual experience developing and implementing a problem-solving process, using the Paulo Freire approach, for teaching English as a second language (ESL) adult students. This process implies a serious and long-term commitment to developing critical thinking skills. The first part of the book discusses who the students are,…

  14. Fast inference of ill-posed problems within a convex space

    NASA Astrophysics Data System (ADS)

    Fernandez-de-Cossio-Diaz, J.; Mulet, R.

    2016-07-01

    In multiple scientific and technological applications we face the problem of having low dimensional data to be justified by a linear model defined in a high dimensional parameter space. The difference in dimensionality makes the problem ill-defined: the model is consistent with the data for many values of its parameters. The objective is to find the probability distribution of parameter values consistent with the data, a problem that can be cast as the exploration of a high dimensional convex polytope. In this work we introduce a novel algorithm to solve this problem efficiently. It provides results that are statistically indistinguishable from currently used numerical techniques while its running time scales linearly with the system size. We show that the algorithm performs robustly in many abstract and practical applications. As working examples we simulate the effects of restricting reaction fluxes on the space of feasible phenotypes of a genome scale Escherichia coli metabolic network and infer the traffic flow between origin and destination nodes in a real communication network.

  15. Analysis and Numerical Analysis of Some Properly and Improperly Posed Problems in Applied Mathematics

    DTIC Science & Technology

    1988-10-14

    In our recent work with Bandle ( "On the Existence and Nonexistence of Global Solutions to Reaction Diffusion Equations in Sectorial Domains" which... evolution equations . (2) Parameter identification problems. ’-" X! C 20 DISTRIBUTION/AVAILABILITY OF ABSTRACT 21 ABSTRACT SECURITY CLASSIFICATION 0...behavior of solutions of nonlinear evolution equations . We con- sidered certain scalar nonlinear hyperbolic and parabolic equations , and also

  16. The anatomical problem posed by brain complexity and size: a potential solution.

    PubMed

    DeFelipe, Javier

    2015-01-01

    Over the years the field of neuroanatomy has evolved considerably but unraveling the extraordinary structural and functional complexity of the brain seems to be an unattainable goal, partly due to the fact that it is only possible to obtain an imprecise connection matrix of the brain. The reasons why reaching such a goal appears almost impossible to date is discussed here, together with suggestions of how we could overcome this anatomical problem by establishing new methodologies to study the brain and by promoting interdisciplinary collaboration. Generating a realistic computational model seems to be the solution rather than attempting to fully reconstruct the whole brain or a particular brain region.

  17. The anatomical problem posed by brain complexity and size: a potential solution

    PubMed Central

    DeFelipe, Javier

    2015-01-01

    Over the years the field of neuroanatomy has evolved considerably but unraveling the extraordinary structural and functional complexity of the brain seems to be an unattainable goal, partly due to the fact that it is only possible to obtain an imprecise connection matrix of the brain. The reasons why reaching such a goal appears almost impossible to date is discussed here, together with suggestions of how we could overcome this anatomical problem by establishing new methodologies to study the brain and by promoting interdisciplinary collaboration. Generating a realistic computational model seems to be the solution rather than attempting to fully reconstruct the whole brain or a particular brain region. PMID:26347617

  18. A well-posed Cauchy problem for an evolution equation with coefficients of low regularity

    NASA Astrophysics Data System (ADS)

    Cicognani, Massimo; Colombini, Ferruccio

    In the hyperbolic Cauchy problem, the well-posedness in Sobolev spaces is strictly related to the modulus of continuity of the coefficients. This holds true for p-evolution equations with real characteristics (p=1 hyperbolic equations, p=2 vibrating plate and Schrödinger type models, …). We show that, for p⩾2, a lack of regularity in t can be balanced by a damping of the too fast oscillations as the space variable x→∞. This cannot happen in the hyperbolic case p=1 because of the finite speed of propagation.

  19. Solution to manufacturer`s hazardous waste poses problem for analyst

    SciTech Connect

    Wickham St. Germain, M.E.

    1997-12-31

    Manufacturers are finding alternative methods for rinsing parts and for cleaning equipment needed in process changes. By using alkaline detergents or polyglymes (i.e., polyethylene glycol), some manufacturers have eliminated or reduced the volume of solvents that they use. Therefore, the manufacturers have reduced the Resource and Recovery Act (RCRA) regulated waste from their facilities, and have reduced the cost of disposal of the waste. The manufacturing processes generate some foam, and the foam is not seen as a problem by the manufacturers as long as the foam can be controlled and rinsed away. Unfortunately, collection of samples with zero headspace is nearly impossible when several inches of foam exist above the effluent. In addition, the required analytical techniques propagate additional foaming by sparging inert gas through the sample or by vigorous shaking. As more manufacturers switch to alkaline detergents or polyglymes, analysts will more frequently face a severe foaming problem which may contaminate analytical instruments or increase the extraction time. This paper will present a brief summary of methods to reduce foaming in the analytical laboratory, a recent literature review on antifoam agents/defoamers, and possible application of defoamers to analytical techniques.

  20. Eigen analysis of tree-ring records: part 2, posing the eigen problem

    NASA Astrophysics Data System (ADS)

    Yang, Bao; Sonechkin, Dmitry M.; Datsenko, Nina M.; Ivashchenko, Nadezda N.; Liu, Jingjing; Qin, Chun

    2012-01-01

    The technique of expanding meteorological fields on eigenvectors of the field covariation matrix is popular. In this paper, we propose for the first time to use a mathematically similar technique to solve the main problem of dendrochronology: classifying variations in tree-ring records as either age- and microenvironment-dependent or climate-induced. Applying this technique to a sample of very long-lived Qilian junipers ( Sabina przewalskii Kom.) from the Dulan region in western China, we demonstrate that the ring-width variations projected on the first eigenvector are age-dependent, but those projected on several of the first subsequent vectors are mainly climate-induced. In particular, the second and third projections capture multi-centennial climatic variations, and the variations projected on the fourth through seventh eigenvectors show periodic variations that are probably induced by the 178-year solar cycle. The projections on the smallest eigenvectors seem to be negligible.

  1. Problem posing and cultural tailoring: developing an HIV/AIDS health literacy toolkit with the African American community.

    PubMed

    Rikard, R V; Thompson, Maxine S; Head, Rachel; McNeil, Carlotta; White, Caressa

    2012-09-01

    The rate of HIV infection among African Americans is disproportionately higher than for other racial groups in the United States. Previous research suggests that low level of health literacy (HL) is an underlying factor to explain racial disparities in the prevalence and incidence of HIV/AIDS. The present research describes a community and university project to develop a culturally tailored HIV/AIDS HL toolkit in the African American community. Paulo Freire's pedagogical philosophy and problem-posing methodology served as the guiding framework throughout the development process. Developing the HIV/AIDS HL toolkit occurred in a two-stage process. In Stage 1, a nonprofit organization and research team established a collaborative partnership to develop a culturally tailored HIV/AIDS HL toolkit. In Stage 2, African American community members participated in focus groups conducted as Freirian cultural circles to further refine the HIV/AIDS HL toolkit. In both stages, problem posing engaged participants' knowledge, experiences, and concerns to evaluate a working draft toolkit. The discussion and implications highlight how Freire's pedagogical philosophy and methodology enhances the development of culturally tailored health information.

  2. Estimating Atmospheric Fe Deposition to the Remote Ocean: the Problems Posed by Solubility Control

    NASA Astrophysics Data System (ADS)

    Measures, C. I.

    2001-12-01

    John Edmond's scientific career was dedicated to exploiting the tracer properties of chemical distributions in the ocean and using these to further our understanding of Earth and ocean processes. He realised that since chemical distributions result from geological, physical and biological processes, their interpretation is a powerful tool that can be used to explain many disparate elements of Earth sciences. In addition, the natural integrating power of chemical distributions over long time scales provides a unique opportunity to temporally average high frequency processes. The ability to apply these tools to current problems requires development and application of methodology that can be used over large temporal and spatial scales. John helped foster the development of real time trace element determinations at sea. A particularly good example of the results that this work has produced is using surface water trace element distributions to develop an understanding of the role that atmospheric deposition processes play in biogeochemical cycles. The partial dissolution of atmospheric dust in surface waters leaves a chemical wake that can be used to determine the magnitude and locus of atmospheric deposition events. In particular, dissolved aluminium concentrations in surface waters appear to be largely driven by atmospheric processes. Thus, modeling of the distribution of this element is being used to develop an understanding of atmospheric deposition processes in oceanic regions that are not suitable for direct sampling. When used in conjunction with surface water distributions of iron, the role of atmospheric deposition for this biologically important element can also be studied. However, the few existing data sets indicate that current models of iron deposition to the surface ocean, which simply apply a fixed fractional solubility of iron in dust, are unlikely to succeed, since the absolute solubility of iron limits the addition of this element to the surface ocean

  3. The Effect of Problem Posing Oriented Analyses-II Course on the Attitudes toward Mathematics and Mathematics Self-Efficacy of Elementary Prospective Mathematics Teachers

    ERIC Educational Resources Information Center

    Akay, Hayri; Boz, Nihat

    2010-01-01

    Research on mathematics teaching and learning has recently focused on affective variables, which were found to play an essential role that influences behaviour and learning. Despite its importance, problem posing has not yet received the attention it warrants from the mathematics education community. Perceived self-efficacy beliefs have been found…

  4. Revisiting mathematical problem solving and posing in the digital era: toward pedagogically sound uses of modern technology

    NASA Astrophysics Data System (ADS)

    Abramovich, S.

    2014-10-01

    The availability of sophisticated computer programs such as Wolfram Alpha has made many problems found in the secondary mathematics curriculum somewhat obsolete for they can be easily solved by the software. Against this background, an interplay between the power of a modern tool of technology and educational constraints it presents is discussed. Using topics from algebra (equations) and elementary number theory (summation of powers of integers), the paper suggests ways of developing problems that are both technology-immune and technology-enabled in the sense that whereas software can facilitate problem solving, its direct application is not sufficient for finding an answer. Stemming from the author's work with secondary mathematics teacher candidates, this paper highlights the appropriate use of technology as support system for multiple ways of knowing and knowledge construction in the modern classroom.

  5. Revisiting Mathematical Problem Solving and Posing in the Digital Era: Toward Pedagogically Sound Uses of Modern Technology

    ERIC Educational Resources Information Center

    Abramovich, S.

    2014-01-01

    The availability of sophisticated computer programs such as "Wolfram Alpha" has made many problems found in the secondary mathematics curriculum somewhat obsolete for they can be easily solved by the software. Against this background, an interplay between the power of a modern tool of technology and educational constraints it presents is…

  6. The "Kind of Problem Cities Pose": Jane Jacobs at the Intersection of Philosophy, Pedagogy, and Urban Theory

    ERIC Educational Resources Information Center

    Fraser, Benjamin

    2009-01-01

    The matter of cities is, as urban critic Jane Jacobs argued, a complex problem akin to the life sciences. As a rich tradition of philosophical and geographical thought has suggested (Bergson, Lefebvre, and Harvey), the city is not a thing but a process. In order to reconcile process methodology and pedagogy, this essay explores six key ideas…

  7. Recycled Water Poses Disinfectant Problem

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1973

    1973-01-01

    Discusses the possible health hazards resulting from released nucleic acid of inactivated viruses, chlorinated nonliving organic molecules, and overestimated reliability of waste treatment standards. Suggests the recycle system use a dual disinfectant such as chlorine and ozone in water treatment. (CC)

  8. Preconditioner and convergence study for the Quantum Computer Aided Design (QCAD) nonlinear poisson problem posed on the Ottawa Flat 270 design geometry.

    SciTech Connect

    Kalashnikova, Irina

    2012-05-01

    A numerical study aimed to evaluate different preconditioners within the Trilinos Ifpack and ML packages for the Quantum Computer Aided Design (QCAD) non-linear Poisson problem implemented within the Albany code base and posed on the Ottawa Flat 270 design geometry is performed. This study led to some new development of Albany that allows the user to select an ML preconditioner with Zoltan repartitioning based on nodal coordinates, which is summarized. Convergence of the numerical solutions computed within the QCAD computational suite with successive mesh refinement is examined in two metrics, the mean value of the solution (an L{sup 1} norm) and the field integral of the solution (L{sup 2} norm).

  9. An ill-posed problem for the Black-Scholes equation for a profitable forecast of prices of stock options on real market data

    NASA Astrophysics Data System (ADS)

    Klibanov, Michael V.; Kuzhuget, Andrey V.; Golubnichiy, Kirill V.

    2016-01-01

    A new empirical mathematical model for the Black-Scholes equation is proposed to forecast option prices. This model includes new interval for the price of the underlying stock, new initial and new boundary conditions. Conventional notions of maturity time and strike prices are not used. The Black-Scholes equation is solved as a parabolic equation with the reversed time, which is an ill-posed problem. Thus, a regularization method is used to solve it. To verify the validity of our model, real market data for 368 randomly selected liquid options are used. A new trading strategy is proposed. Our results indicates that our method is profitable on those options. Furthermore, it is shown that the performance of two simple extrapolation-based techniques is much worse. We conjecture that our method might lead to significant profits of those financial insitutions which trade large amounts of options. We caution, however, that further studies are necessary to verify this conjecture.

  10. SU-E-T-398: Evaluation of Radiobiological Parameters Using Serial Tumor Imaging During Radiotherapy as An Inverse Ill-Posed Problem

    SciTech Connect

    Chvetsov, A; Sandison, G; Schwartz, J; Rengan, R

    2015-06-15

    Purpose: Combination of serial tumor imaging with radiobiological modeling can provide more accurate information on the nature of treatment response and what underlies resistance. The purpose of this article is to improve the algorithms related to imaging-based radiobilogical modeling of tumor response. Methods: Serial imaging of tumor response to radiation therapy represents a sum of tumor cell sensitivity, tumor growth rates, and the rate of cell loss which are not separated explicitly. Accurate treatment response assessment would require separation of these radiobiological determinants of treatment response because they define tumor control probability. We show that the problem of reconstruction of radiobiological parameters from serial imaging data can be considered as inverse ill-posed problem described by the Fredholm integral equation of the first kind because it is governed by a sum of several exponential processes. Therefore, the parameter reconstruction can be solved using regularization methods. Results: To study the reconstruction problem, we used a set of serial CT imaging data for the head and neck cancer and a two-level cell population model of tumor response which separates the entire tumor cell population in two subpopulations of viable and lethally damage cells. The reconstruction was done using a least squared objective function and a simulated annealing algorithm. Using in vitro data for radiobiological parameters as reference data, we shown that the reconstructed values of cell surviving fractions and potential doubling time exhibit non-physical fluctuations if no stabilization algorithms are applied. The variational regularization allowed us to obtain statistical distribution for cell surviving fractions and cell number doubling times comparable to in vitro data. Conclusion: Our results indicate that using variational regularization can increase the number of free parameters in the model and open the way to development of more advanced

  11. Posing Einstein's Question: Questioning Einstein's Pose.

    ERIC Educational Resources Information Center

    Topper, David; Vincent, Dwight E.

    2000-01-01

    Discusses the events surrounding a famous picture of Albert Einstein in which he poses near a blackboard containing a tensor form of his 10 field equations for pure gravity with a question mark after it. Speculates as to the content of Einstein's lecture and the questions he might have had about the equation. (Contains over 30 references.) (WRM)

  12. Pose and motion from contact

    SciTech Connect

    Jia, Y.B.; Erdmann, M.

    1999-05-01

    In the absence of vision, grasping an object often relies on tactile feedback from the fingertips. As the finger pushes the object, the fingertip can feel the contact point move. If the object is known in advance, from this motion the finger may infer the location of the contact point on the object, and thereby, the object pose. This paper primarily investigates the problem of determining the pose (orientation and position) and motion (velocity and angular velocity) of a planar object with known geometry from such contact motion generated by pushing. A dynamic analysis of pushing yields a nonlinear system that relates through contact the object pose and motion to the finger motion. The contact motion on the fingertip thus encodes certain information about the object pose. Nonlinear observability theory is employed to show that such information is sufficient for the finger to observe not only the pose, but also the motion of the object. Therefore, a sensing strategy can be realized as an observer of the nonlinear dynamic system. Two observers are subsequently introduced. The first observer, based on the work of Gautheir, Hammouri, and Othman (1992), has its gain determined by the solution of a Lyapunov-like equation; it can be activated at any time instant during a push. The second observer, based on Newton`s method, solves for the initial (motionless) object pose from three intermediate contact points during a push. Under the Coulomb-friction model, the paper deals with support friction in the plane and/or contact friction between the finger and the object. Extensive simulations have been done to demonstrate the feasibility of the two observers. Preliminary experiments (with an Adept robot) have also been conducted. A contact sensor has been implemented using strain gauges.

  13. Phase unwrapping as an ill-posed problem: performance comparison between a neural-network-based approach and a stochastic search method

    NASA Astrophysics Data System (ADS)

    Chiaradia, Maria T.; Guerriero, Luciano; Refice, Alberto; Pasquariello, Guido; Satalino, Giuseppe; Stramaglia, Sebastiano

    1998-10-01

    2D phase unwrapping, a problem common to signal processing, optics, and interferometric radar topographic applications, consists in retrieving an absolute phase field from principal, noisy measurements. In this paper, we analyze the application of neural networks to this complex mathematical problem, formulating it as a learning-by-examples strategy, by training a multilayer perceptron to associate a proper correction pattern to the principal phase gradient configuration on local window. In spite of the high dimensionality of this problem the proposed MLP, trained on examples from simulated phase surfaces, shows to be able to correctly remove more than half the original number of pointlike inconsistencies on real noisy interferograms. Better efficiencies could be achieved by enlarging the processing window size, so as to exploit a greater amount of information. By pushing further this change of perspective, one passes from a local to a global point of view; problems of this kind are more effectively solved, rather than through learning strategies, by minimization procedures, for which we prose a powerful algorithm, based on a stochastic approach.

  14. Contact Zones, Problem Posing and Critical Consciousness

    ERIC Educational Resources Information Center

    Patel, Lisa

    2012-01-01

    In this article, I share the shape and findings of a participatory action research project with newcomer youths on the contours of status in society. This project was nested in a professional internship experience for newcomer youth, and this experience provided the context in which we explored how privilege and status are afforded in American…

  15. Potential Energy Sources Pose Mining Problem

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1974

    1974-01-01

    Summarizes the discussions of a Division of Industrial and Engineering Chemistry symposium on solids handling for synthetic fuels production. Included is a description of technical difficulties with the use of coal seams and deposits of oil shale and oil sand as potential sources of fuel. (CC)

  16. [Therapeutic problems posed by various angiodysplasias].

    PubMed

    Maraval, M

    1980-01-01

    The clinical and anatomical aspects of the angiodysplasias are multiple and numerous classifications have been proposed. After review of a more simple classification put forward by Natali and Merland based on the contribution of superselective arteriography, consideration is given to a therapeutic approach for each angiodysplasia. Whereas for a long time the only therapeutic alternatives have been between surgery and no surgery, improved arteriographic understanding of these lesions has now permitted improved treatment, by surgery or by embolization or by the combination of the two methods. Finally the fields of the pure arterial dysplasias and the rares phacomatoses are considered, with a therapeutic scheme in each case.

  17. Electronic materials pose challenges

    SciTech Connect

    Frezzo, D.C.

    1986-04-01

    To prove that the Strategic Defense Initiative (SDI) is technically feasible, several demanding scientific and engineering criteria must be met. Electronic materials processing and electronics reliability are the challenging areas where it is necessary to demonstrate that SDI would be effective, survivable, and cost-effective. The rad-hardened ICs which enable sensors to see and which are critical to the surveillance satellites demonstrate the complexity of the problem. A long-term interest in SDI research will drive much of the world's technical development for decades, and indirectly affect the professional roles of scientists and engineers, who have both a social and technical responsibility to contribute to the debate.

  18. Factoring Algebraic Error for Relative Pose Estimation

    SciTech Connect

    Lindstrom, P; Duchaineau, M

    2009-03-09

    We address the problem of estimating the relative pose, i.e. translation and rotation, of two calibrated cameras from image point correspondences. Our approach is to factor the nonlinear algebraic pose error functional into translational and rotational components, and to optimize translation and rotation independently. This factorization admits subproblems that can be solved using direct methods with practical guarantees on global optimality. That is, for a given translation, the corresponding optimal rotation can directly be determined, and vice versa. We show that these subproblems are equivalent to computing the least eigenvector of second- and fourth-order symmetric tensors. When neither translation or rotation is known, alternating translation and rotation optimization leads to a simple, efficient, and robust algorithm for pose estimation that improves on the well-known 5- and 8-point methods.

  19. Accurate pose estimation for forensic identification

    NASA Astrophysics Data System (ADS)

    Merckx, Gert; Hermans, Jeroen; Vandermeulen, Dirk

    2010-04-01

    In forensic authentication, one aims to identify the perpetrator among a series of suspects or distractors. A fundamental problem in any recognition system that aims for identification of subjects in a natural scene is the lack of constrains on viewing and imaging conditions. In forensic applications, identification proves even more challenging, since most surveillance footage is of abysmal quality. In this context, robust methods for pose estimation are paramount. In this paper we will therefore present a new pose estimation strategy for very low quality footage. Our approach uses 3D-2D registration of a textured 3D face model with the surveillance image to obtain accurate far field pose alignment. Starting from an inaccurate initial estimate, the technique uses novel similarity measures based on the monogenic signal to guide a pose optimization process. We will illustrate the descriptive strength of the introduced similarity measures by using them directly as a recognition metric. Through validation, using both real and synthetic surveillance footage, our pose estimation method is shown to be accurate, and robust to lighting changes and image degradation.

  20. Human pose tracking from monocular video by traversing an image motion mapped body pose manifold

    NASA Astrophysics Data System (ADS)

    Basu, Saurav; Poulin, Joshua; Acton, Scott T.

    2010-01-01

    Tracking human pose from monocular video sequences is a challenging problem due to the large number of independent parameters affecting image appearance and nonlinear relationships between generating parameters and the resultant images. Unlike the current practice of fitting interpolation functions to point correspondences between underlying pose parameters and image appearance, we exploit the relationship between pose parameters and image motion flow vectors in a physically meaningful way. Change in image appearance due to pose change is realized as navigating a low dimensional submanifold of the infinite dimensional Lie group of diffeomorphisms of the two dimensional sphere S2. For small changes in pose, image motion flow vectors lie on the tangent space of the submanifold. Any observed image motion flow vector field is decomposed into the basis motion vector flow fields on the tangent space and combination weights are used to update corresponding pose changes in the different dimensions of the pose parameter space. Image motion flow vectors are largely invariant to style changes in experiments with synthetic and real data where the subjects exhibit variation in appearance and clothing. The experiments demonstrate the robustness of our method (within +/-4° of ground truth) to style variance.

  1. POSE Algorithms for Automated Docking

    NASA Technical Reports Server (NTRS)

    Heaton, Andrew F.; Howard, Richard T.

    2011-01-01

    POSE (relative position and attitude) can be computed in many different ways. Given a sensor that measures bearing to a finite number of spots corresponding to known features (such as a target) of a spacecraft, a number of different algorithms can be used to compute the POSE. NASA has sponsored the development of a flash LIDAR proximity sensor called the Vision Navigation Sensor (VNS) for use by the Orion capsule in future docking missions. This sensor generates data that can be used by a variety of algorithms to compute POSE solutions inside of 15 meters, including at the critical docking range of approximately 1-2 meters. Previously NASA participated in a DARPA program called Orbital Express that achieved the first automated docking for the American space program. During this mission a large set of high quality mated sensor data was obtained at what is essentially the docking distance. This data set is perhaps the most accurate truth data in existence for docking proximity sensors in orbit. In this paper, the flight data from Orbital Express is used to test POSE algorithms at 1.22 meters range. Two different POSE algorithms are tested for two different Fields-of-View (FOVs) and two different pixel noise levels. The results of the analysis are used to predict future performance of the POSE algorithms with VNS data.

  2. Person re-identification by pose priors

    NASA Astrophysics Data System (ADS)

    Bak, Slawomir; Martins, Filipe; Bremond, Francois

    2015-03-01

    The person re-identification problem is a well known retrieval task that requires finding a person of interest in a network of cameras. In a real-world scenario, state of the art algorithms are likely to fail due to serious perspective and pose changes as well as variations in lighting conditions across the camera network. The most effective approaches try to cope with all these changes by applying metric learning tools to find a transfer function between a camera pair. Unfortunately, this transfer function is usually dependent on the camera pair and requires labeled training data for each camera. This might be unattainable in a large camera network. In this paper, instead of learning the transfer function that addresses all appearance changes, we propose to learn a generic metric pool that only focuses on pose changes. This pool consists of metrics, each one learned to match a specific pair of poses. Automatically estimated poses determine the proper metric, thus improving matching. We show that metrics learned using a single camera improve the matching across the whole camera network, providing a scalable solution. We validated our approach on a publicly available dataset demonstrating increase in the re-identification performance.

  3. MINACE-filter-based facial pose estimation

    NASA Astrophysics Data System (ADS)

    Casasent, David P.; Patnaik, Rohit

    2005-03-01

    A facial pose estimation system is presented that functions with illumination variations present. Pose estimation is a useful first stage in a face recognition system. A separate minimum noise and correlation energy (MINACE) filter is synthesized for each pose. To select the MINACE parameter c for the filter for a pose, a training set of illumination differences of several faces at that pose, and a validation set of other poses (illumination differences of several faces at a few other poses) is used in the automated filter-synthesis step. However, the filter for each pose is a combination of faces at only that pose. The pose estimation system is evaluated using images from the CMU Pose, Illumination and Expression (PIE) database. The classification performance (PC) scores are presented for several pose estimation tests. The pose estimate will be used for a subsequent image transformation of a test face to a reference pose for face identification.

  4. 3-D Pose Presentation for Training Applications

    ERIC Educational Resources Information Center

    Fox, Kaitlyn; Whitehead, Anthony

    2011-01-01

    Purpose: In the authors' experience, the biggest issue with pose-based exergames is the difficulty in effectively communicating a three-dimensional pose to a user to facilitate a thorough understanding for accurate pose replication. The purpose of this paper is to examine options for pose presentation. Design/methodology/approach: The authors…

  5. Human Pose Estimation from Monocular Images: A Comprehensive Survey

    PubMed Central

    Gong, Wenjuan; Zhang, Xuena; Gonzàlez, Jordi; Sobral, Andrews; Bouwmans, Thierry; Tu, Changhe; Zahzah, El-hadi

    2016-01-01

    Human pose estimation refers to the estimation of the location of body parts and how they are connected in an image. Human pose estimation from monocular images has wide applications (e.g., image indexing). Several surveys on human pose estimation can be found in the literature, but they focus on a certain category; for example, model-based approaches or human motion analysis, etc. As far as we know, an overall review of this problem domain has yet to be provided. Furthermore, recent advancements based on deep learning have brought novel algorithms for this problem. In this paper, a comprehensive survey of human pose estimation from monocular images is carried out including milestone works and recent advancements. Based on one standard pipeline for the solution of computer vision problems, this survey splits the problem into several modules: feature extraction and description, human body models, and modeling methods. Problem modeling methods are approached based on two means of categorization in this survey. One way to categorize includes top-down and bottom-up methods, and another way includes generative and discriminative methods. Considering the fact that one direct application of human pose estimation is to provide initialization for automatic video surveillance, there are additional sections for motion-related methods in all modules: motion features, motion models, and motion-based methods. Finally, the paper also collects 26 publicly available data sets for validation and provides error measurement methods that are frequently used. PMID:27898003

  6. Flameless Candle Batteries Pose Risk to Kids

    MedlinePlus

    ... medlineplus.gov/news/fullstory_162882.html Flameless Candle Batteries Pose Risk to Kids If swallowed, serious damage ... WEDNESDAY, Jan. 4, 2017 (HealthDay News) -- Tiny button batteries that light up flameless "tea candles" pose a ...

  7. Fast human pose estimation using 3D Zernike descriptors

    NASA Astrophysics Data System (ADS)

    Berjón, Daniel; Morán, Francisco

    2012-03-01

    Markerless video-based human pose estimation algorithms face a high-dimensional problem that is frequently broken down into several lower-dimensional ones by estimating the pose of each limb separately. However, in order to do so they need to reliably locate the torso, for which they typically rely on time coherence and tracking algorithms. Their losing track usually results in catastrophic failure of the process, requiring human intervention and thus precluding their usage in real-time applications. We propose a very fast rough pose estimation scheme based on global shape descriptors built on 3D Zernike moments. Using an articulated model that we configure in many poses, a large database of descriptor/pose pairs can be computed off-line. Thus, the only steps that must be done on-line are the extraction of the descriptors for each input volume and a search against the database to get the most likely poses. While the result of such process is not a fine pose estimation, it can be useful to help more sophisticated algorithms to regain track or make more educated guesses when creating new particles in particle-filter-based tracking schemes. We have achieved a performance of about ten fps on a single computer using a database of about one million entries.

  8. Image-based aircraft pose estimation: a comparison of simulations and real-world data

    NASA Astrophysics Data System (ADS)

    Breuers, Marcel G. J.; de Reus, Nico

    2001-10-01

    The problem of estimating aircraft pose information from mono-ocular image data is considered using a Fourier descriptor based algorithm. The dependence of pose estimation accuracy on image resolution and aspect angle is investigated through simulations using sets of synthetic aircraft images. Further evaluation shows that god pose estimation accuracy can be obtained in real world image sequences.

  9. Viewpoint Invariant Gesture Recognition and 3D Hand Pose Estimation Using RGB-D

    ERIC Educational Resources Information Center

    Doliotis, Paul

    2013-01-01

    The broad application domain of the work presented in this thesis is pattern classification with a focus on gesture recognition and 3D hand pose estimation. One of the main contributions of the proposed thesis is a novel method for 3D hand pose estimation using RGB-D. Hand pose estimation is formulated as a database retrieval problem. The proposed…

  10. Algorithms for striking material and energy balances in calculating the technical-and-economic indicators of thermal power plant equipment based on the ill-posed problem regularization method

    NASA Astrophysics Data System (ADS)

    Leduhovsky, G. V.; Zhukov, V. P.; Barochkin, E. V.; Zimin, A. P.; Razinkov, A. A.

    2015-08-01

    The problem of striking material and energy balances from the data received by thermal power plant computerized automation systems from the technical accounting systems with the accuracy determined by the metrological characteristics of serviceable calibrated instruments is formulated using the mathematical apparatus of ridge regression method. A graph theory based matrix model of material and energy flows in systems having an intricate structure is proposed, using which it is possible to formalize the solution of a particular practical problem at the stage of constructing the system model. The problem of striking material and energy balances is formulated taking into account different degrees of trustworthiness with which the initial flow rates of coolants and their thermophysical parameters were determined, as well as process constraints expressed in terms of balance correlations on mass and energy for individual system nodes or for any combination thereof. Analytic and numerical solutions of the problem are proposed in different versions of its statement differing from each other in the adopted assumptions and considered constraints. It is shown how the procedure for striking material and energy balances from the results of measuring the flows of feed water and steam in the thermal process circuit of a combined heat and power plant affects the calculation accuracy of specific fuel rates for supplying heat and electricity. It has been revealed that the nominal values of indicators and the fuel saving or overexpenditure values associated with these indicators are the most dependent parameters. In calculating these quantities using different balance striking procedures, an error may arise the value of which is commensurable with the power plant thermal efficiency margin stipulated by the regulatory-technical documents on using fuel. The study results were used for substantiating the choice of stating the problem of striking material and fuel balances, as well as

  11. Pose-Invariant Face Recognition via RGB-D Images

    PubMed Central

    Sang, Gaoli; Li, Jing; Zhao, Qijun

    2016-01-01

    Three-dimensional (3D) face models can intrinsically handle large pose face recognition problem. In this paper, we propose a novel pose-invariant face recognition method via RGB-D images. By employing depth, our method is able to handle self-occlusion and deformation, both of which are challenging problems in two-dimensional (2D) face recognition. Texture images in the gallery can be rendered to the same view as the probe via depth. Meanwhile, depth is also used for similarity measure via frontalization and symmetric filling. Finally, both texture and depth contribute to the final identity estimation. Experiments on Bosphorus, CurtinFaces, Eurecom, and Kiwi databases demonstrate that the additional depth information has improved the performance of face recognition with large pose variations and under even more challenging conditions. PMID:26819581

  12. Robust head pose estimation via supervised manifold learning.

    PubMed

    Wang, Chao; Song, Xubo

    2014-05-01

    Head poses can be automatically estimated using manifold learning algorithms, with the assumption that with the pose being the only variable, the face images should lie in a smooth and low-dimensional manifold. However, this estimation approach is challenging due to other appearance variations related to identity, head location in image, background clutter, facial expression, and illumination. To address the problem, we propose to incorporate supervised information (pose angles of training samples) into the process of manifold learning. The process has three stages: neighborhood construction, graph weight computation and projection learning. For the first two stages, we redefine inter-point distance for neighborhood construction as well as graph weight by constraining them with the pose angle information. For Stage 3, we present a supervised neighborhood-based linear feature transformation algorithm to keep the data points with similar pose angles close together but the data points with dissimilar pose angles far apart. The experimental results show that our method has higher estimation accuracy than the other state-of-art algorithms and is robust to identity and illumination variations.

  13. Perspective projection for variance pose face recognition from camera calibration

    NASA Astrophysics Data System (ADS)

    Fakhir, M. M.; Woo, W. L.; Chambers, J. A.; Dlay, S. S.

    2016-04-01

    Variance pose is an important research topic in face recognition. The alteration of distance parameters across variance pose face features is a challenging. We provide a solution for this problem using perspective projection for variance pose face recognition. Our method infers intrinsic camera parameters of the image which enable the projection of the image plane into 3D. After this, face box tracking and centre of eyes detection can be identified using our novel technique to verify the virtual face feature measurements. The coordinate system of the perspective projection for face tracking allows the holistic dimensions for the face to be fixed in different orientations. The training of frontal images and the rest of the poses on FERET database determine the distance from the centre of eyes to the corner of box face. The recognition system compares the gallery of images against different poses. The system initially utilises information on position of both eyes then focuses principally on closest eye in order to gather data with greater reliability. Differentiation between the distances and position of the right and left eyes is a unique feature of our work with our algorithm outperforming other state of the art algorithms thus enabling stable measurement in variance pose for each individual.

  14. Neuromorphic Event-Based 3D Pose Estimation

    PubMed Central

    Reverter Valeiras, David; Orchard, Garrick; Ieng, Sio-Hoi; Benosman, Ryad B.

    2016-01-01

    Pose estimation is a fundamental step in many artificial vision tasks. It consists of estimating the 3D pose of an object with respect to a camera from the object's 2D projection. Current state of the art implementations operate on images. These implementations are computationally expensive, especially for real-time applications. Scenes with fast dynamics exceeding 30–60 Hz can rarely be processed in real-time using conventional hardware. This paper presents a new method for event-based 3D object pose estimation, making full use of the high temporal resolution (1 μs) of asynchronous visual events output from a single neuromorphic camera. Given an initial estimate of the pose, each incoming event is used to update the pose by combining both 3D and 2D criteria. We show that the asynchronous high temporal resolution of the neuromorphic camera allows us to solve the problem in an incremental manner, achieving real-time performance at an update rate of several hundreds kHz on a conventional laptop. We show that the high temporal resolution of neuromorphic cameras is a key feature for performing accurate pose estimation. Experiments are provided showing the performance of the algorithm on real data, including fast moving objects, occlusions, and cases where the neuromorphic camera and the object are both in motion. PMID:26834547

  15. Astronauts Hart and Crippen pose with MMU

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Astronaut Terry J. Hart, 41-C mission specialist, poses with a mockup of the manned maneuvering unit (MMU) in the JSC mockup and integration laboratory (29463); Astronaut Robert L. Crippen, 41-C crew commander, poses with a ground training version of the MMU in the JSC mockup and integration laboratory (29464).

  16. Performance d'un hôpital de zone sanitaire au Benin: un exemple de modèle d’évaluation

    PubMed Central

    Ahanhanzo, Yolaine Glèlè; Ouédraogo, Landaogo Soutongonoma Lionel; Saizonou, Jacques

    2014-01-01

    Introduction Premier niveau de référence de la pyramide sanitaire du Bénin, les hôpitaux de zone sanitaire s'acquittent de leurs missions dans un contexte difficile. L'objectif de la présente étude a été d’évaluer la performance de l'hôpital de la zone sanitaire de Comè en 2013. Méthodes L’étude était transversale, descriptive et évaluative. Les services retenus ont été sélectionnés par choix raisonné du fait de leur contribution au paquet d'activités de l'hôpital. Les clients externes et internes ont été sélectionnés par commodité. Les membres du conseil de gestion de l'hôpital de zone, les responsables d'organisation à base communautaire, les partenaires techniques et financiers ainsi que des chefs d'arrondissement ont été sélectionné par choix raisonné. La performance de l'hôpital a été mesurée à travers trois critères que sont la qualité des prestations, leur équité d'accès et leur pérennité. L'analyse des données a été faite sur la base de critères en utilisant une cotation analytique puis temporelle. Résultats La performance de l'hôpital de la zone sanitaire de Comè était très faible au premier semestre 2013 avec une qualité des prestations cotée à 35%, une équité d'accès cotée à 50% et une pérennité des actions cotée à 11%. Seul le niveau d'application de la fonction gouvernance était moyen. La méconnaissance des attributions des représentants de la communauté dans les instances de l'hôpital a constitué une limite à leur implication dans l'exercice des fonctions de l'hôpital. Les partenaires techniques et financiers ont participé au renforcement institutionnel de l'hôpital en termes d'amélioration du plateau technique. Conclusion L'application des fonctions de l'hôpital et une meilleure implication de la communauté ainsi que des partenaires contribueront à l'amélioration de la performance de l'hôpital de la zone sanitaire de Comè. PMID:25400830

  17. Tracking Human Pose Using Max-Margin Markov Models.

    PubMed

    Zhao, Lin; Gao, Xinbo; Tao, Dacheng; Li, Xuelong

    2015-12-01

    We present a new method for tracking human pose by employing max-margin Markov models. Representing a human body by part-based models, such as pictorial structure, the problem of pose tracking can be modeled by a discrete Markov random field. Considering max-margin Markov networks provide an efficient way to deal with both structured data and strong generalization guarantees, it is thus natural to learn the model parameters using the max-margin technique. Since tracking human pose needs to couple limbs in adjacent frames, the model will introduce loops and will be intractable for learning and inference. Previous work has resorted to pose estimation methods, which discard temporal information by parsing frames individually. Alternatively, approximate inference strategies have been used, which can overfit to statistics of a particular data set. Thus, the performance and generalization of these methods are limited. In this paper, we approximate the full model by introducing an ensemble of two tree-structured sub-models, Markov networks for spatial parsing and Markov chains for temporal parsing. Both models can be trained jointly using the max-margin technique, and an iterative parsing process is proposed to achieve the ensemble inference. We apply our model on three challengeable data sets, which contains highly varied and articulated poses. Comprehensive experimental results demonstrate the superior performance of our method over the state-of-the-art approaches.

  18. Manifolds for pose tracking from monocular video

    NASA Astrophysics Data System (ADS)

    Basu, Saurav; Poulin, Joshua; Acton, Scott T.

    2015-03-01

    We formulate a simple human-pose tracking theory from monocular video based on the fundamental relationship between changes in pose and image motion vectors. We investigate the natural embedding of the low-dimensional body pose space into a high-dimensional space of body configurations that behaves locally in a linear manner. The embedded manifold facilitates the decomposition of the image motion vectors into basis motion vector fields of the tangent space to the manifold. This approach benefits from the style invariance of image motion flow vectors, and experiments to validate the fundamental theory show reasonable accuracy (within 4.9 deg of the ground truth).

  19. Effects of Generative Video on Students' Scientific Problem Posing. Draft.

    ERIC Educational Resources Information Center

    Hickey, Daniel T.; Petrosino, Anthony

    A central premise of the discovery-learning and progressive education movements was that the child's own questions are the most appropriate starting point for instruction. Recent advances present new opportunities for discovery-oriented learning. This project has been attempting to create a classroom environment which affords students the…

  20. Use of registry employees can pose legal problems.

    PubMed

    Hoffman, S F

    1994-07-01

    In view of the potential legal liability to which a recipient entity can be exposed when using registry employees, some care must be taken in drafting registry contract services and in modulating the recipient entity's behavior towards the registry personnel. The following steps should generally be taken by health care establishments purchasing registry services to minimize such exposure: (1) Ensure that the registry treats its personnel as employees and complies with all applicable employment law obligations, including state and federal employment tax requirements, workers' compensation laws, and any state law wage and hour requirements in the recipient's state. (2) If using an out-of-state registry, make sure that the registry also has workers' compensation insurance in the recipient's state and complies with that state workers' compensation laws. (3) Make sure that termination decisions regarding registry employees are not made for reasons that violate any federal anti-discrimination laws. (4) Provide in the registry agreement for full indemnification by the registry to the recipient. (5) Ensure that the registry is solvent and has adequate insurance to honor its indemnification obligation. (6) Obtain a warranty from the registry that it carefully screens all of its employees before hiring them. (7) Expressly state in the registry agreement that the registry has the right to discipline and supervise the personnel it refers. (8) Do not reject registry personnel for reasons that would be improper with respect to the facility's own employees, e.g., race, sex, age, religion, disability, etc.

  1. Numerical Solution of Ill Posed Problems in Partial Differential Equations

    DTIC Science & Technology

    1988-06-30

    periodic solutions of semilinear wave equations in exterior domains (breathers). Necessary and sufficient conditions for the existence of such solutions...numerically, that radial, global , positive solutions of the equation div grad u + uq u = 0 (X > 0, q > 1). ((1+1grad ul ) / exist for all X sufficiently... equation with a semilinear boundary condition , to appear in SIAM J. Math. Anal. 17] Levine, H.A. and Protter, M.H., The breakdown of solutions of

  2. Numerical Solution of Ill Posed Problems in Partial Differential Equations.

    DTIC Science & Technology

    1987-09-01

    periodic solutions of semilinear wave equations in exterior domains (breathers). Necessary and sufficient conditions for the existence of such...Crandall, M.G., and Sacks, P.E., Some L1 existence and depandence results for semilinear elliptic equations under nonlinear boundary conditions , to...the former case, a convective diffusion equation with a semilinear source in the boundary condition was analyzed. A fairly complete picture of the

  3. Leveling Students' Creative Thinking in Solving and Posing Mathematical Problem

    ERIC Educational Resources Information Center

    Siswono, Tatag Yuli Eko

    2010-01-01

    Many researchers assume that people are creative, but their degree of creativity is different. The notion of creative thinking level has been discussed .by experts. The perspective of mathematics creative thinking refers to a combination of logical and divergent thinking which is based on intuition but has a conscious aim. The divergent thinking…

  4. Joining problems posed by the development of materials

    NASA Astrophysics Data System (ADS)

    Colombie, M.

    A review of new materials is conducted to examine joining difficulties caused by the properties of the advanced materials. Attention is given to recent developments in the areas of polymers, ceramics, composite materials, and metal alloys. Fabrication procedures are outlined for traditional metals including continuous methods, and associated levels of purity are described that can be achieved with traditional materials such as steel. Recently developed materials discussed include 'multimaterials' such as Al alloys and polymer composites as well as the metallurgical techniques developed for their fabrication. The production of metal/ceramic combinations by means of diffusion bonding and welding is shown to require development, and fabrication methods are required that insure the production of reproducible and consistent materials.

  5. Hazardous Waste Sites Pose Investigation, Evaluation, Scientific, and Legal Problems.

    DTIC Science & Technology

    1981-04-24

    EPA has emphasized the development of short- term tests to detect a chemical’s genotoxic potential, that is, its ability to alter a cell’s genetic... wave of incredulity through the Michigan farm community. No appeal was filedi. The ruling also had a significant impact on the approxi- mately 83 other...measurements such as ground penetrating radar, seismic reflection, electromagnetic induction, and magnetometry will be made to help in detailed geophysical

  6. Problem Posing in Teacher Education: A Freirian Approach

    ERIC Educational Resources Information Center

    Houser, Neil O.

    2007-01-01

    What kinds of ideas and issues do teachers, students, and citizens in general need to think about at this time in the history of society? And how can we in higher education address these important matters? This article offers one means by which such issues might be approached, in and through teacher education. Drawing on the critical work of Paulo…

  7. Genetic Research on Biospecimens Poses Minimal Risk

    PubMed Central

    Wendler, David S.; Rid, Annette

    2014-01-01

    Genetic research on human biospecimens is increasingly common. Yet, debate continues over the level of risk that this research poses to sample donors. Some argue that genetic research on biospecimens poses minimal risk; others argue that it poses greater than minimal risk and therefore needs additional requirements and limitations. This debate raises concern that some donors are not receiving appropriate protection or, conversely, that valuable research is being subject to unnecessary requirements and limitations. The present paper attempts to address this concern using the widely-endorsed ‘risks of daily life’ standard. The three extant versions of this standard all suggest that, with proper measures in place to protect donor confidentiality, most genetic research on human biospecimens poses minimal risk to donors. PMID:25530152

  8. Robust pose determination for autonomous docking

    SciTech Connect

    Goddard, J.S.; Jatko, W.B.; Ferrell, R.K.; Gleason, S.S.

    1995-12-31

    This paper describes current work at the Oak Ridge National Laboratory to develop a robotic vision system capable of recognizing designated objects by their intrinsic geometry. This method, based on single camera vision, combines point features and a model-based technique using geometric feature matching for the pose calculation. In this approach, 2-D point features are connected into higher-order shapes and then matched with corresponding features of the model. Pose estimates are made using a closed-form point solution based on model features of four coplanar points. Rotations are represented by quaternions that simplify the calculations in determining the least squares solution for the coordinate transformation. This pose determination method including image acquisition, feature extraction, feature correspondence, and pose calculation has been implemented on a real-time system using a standard camera and image processing hardware. Experimental results are given for relative error measurements.

  9. CHALLENGES POSED BY RETIRED RUSSIAN NUCLEAR SUBMARINES

    SciTech Connect

    Rudolph, Dieter; Kroken, Ingjerd; Latyshev, Eduard; Griffith, Andrew

    2003-02-27

    The purpose of this paper is to provide an overview of the challenges posed by retired Russian nuclear submarines, review current U.S. and International efforts and provide an assessment of the success of these efforts.

  10. Exemplar-based human action pose correction.

    PubMed

    Shen, Wei; Deng, Ke; Bai, Xiang; Leyvand, Tommer; Guo, Baining; Tu, Zhuowen

    2014-07-01

    The launch of Xbox Kinect has built a very successful computer vision product and made a big impact on the gaming industry. This sheds lights onto a wide variety of potential applications related to action recognition. The accurate estimation of human poses from the depth image is universally a critical step. However, existing pose estimation systems exhibit failures when facing severe occlusion. In this paper, we propose an exemplar-based method to learn to correct the initially estimated poses. We learn an inhomogeneous systematic bias by leveraging the exemplar information within a specific human action domain. Furthermore, as an extension, we learn a conditional model by incorporation of pose tags to further increase the accuracy of pose correction. In the experiments, significant improvements on both joint-based skeleton correction and tag prediction are observed over the contemporary approaches, including what is delivered by the current Kinect system. Our experiments for the facial landmark correction also illustrate that our algorithm can improve the accuracy of other detection/estimation systems.

  11. Evaluation and Improvement of Student's Question-Posing Ability in a Web-Based Learning Environment

    ERIC Educational Resources Information Center

    Lan, Yu-Feng; Lin, Pin-Chuan

    2011-01-01

    With the rapid development of web-based learning environments, question-posing activities have become an important teaching and learning mode. However, this learning approach has some difficulties, one being the lack of a practical approach to assist teachers in evaluating the question-posing ability of all learners. To remedy this problem, the…

  12. Threat Posed by Mounting Vigilantism in Mexico

    DTIC Science & Technology

    2011-09-01

    Perro’s body was found in the trunk of a vehicle occu- pied by Ismael Quintero Oliver, 32, and Marcos Érik Pérez Mora, 21, who belonged to a”Drivers...POSED BY MOUNTING VIGILANTISM IN MEXICO George W. Grayson U.S. ARMY WAR COLLEGE ,....~ .... :!iO.L STRATEGIC STUDIES INSTITUTE Report...TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Threat Posed by Mounting Vigilantism in Mexico 5a. CONTRACT NUMBER 5b

  13. Maximal likelihood correspondence estimation for face recognition across pose.

    PubMed

    Li, Shaoxin; Liu, Xin; Chai, Xiujuan; Zhang, Haihong; Lao, Shihong; Shan, Shiguang

    2014-10-01

    Due to the misalignment of image features, the performance of many conventional face recognition methods degrades considerably in across pose scenario. To address this problem, many image matching-based methods are proposed to estimate semantic correspondence between faces in different poses. In this paper, we aim to solve two critical problems in previous image matching-based correspondence learning methods: 1) fail to fully exploit face specific structure information in correspondence estimation and 2) fail to learn personalized correspondence for each probe image. To this end, we first build a model, termed as morphable displacement field (MDF), to encode face specific structure information of semantic correspondence from a set of real samples of correspondences calculated from 3D face models. Then, we propose a maximal likelihood correspondence estimation (MLCE) method to learn personalized correspondence based on maximal likelihood frontal face assumption. After obtaining the semantic correspondence encoded in the learned displacement, we can synthesize virtual frontal images of the profile faces for subsequent recognition. Using linear discriminant analysis method with pixel-intensity features, state-of-the-art performance is achieved on three multipose benchmarks, i.e., CMU-PIE, FERET, and MultiPIE databases. Owe to the rational MDF regularization and the usage of novel maximal likelihood objective, the proposed MLCE method can reliably learn correspondence between faces in different poses even in complex wild environment, i.e., labeled face in the wild database.

  14. Common Core Poses Challenges for Preschools

    ERIC Educational Resources Information Center

    Zubrzycki, Jaclyn

    2011-01-01

    Although the common-core standards are calibrated to ensure that students leave K-12 schools ready for work and college, they are also posing challenges for the educators who work with children just starting out their school careers. As 46 states and the District of Columbia work this year to put the new curricular guidelines in place, preschool…

  15. "Light" Tobacco Products Pose Heavy Health Risks

    MedlinePlus

    ... Products For Consumers Home For Consumers Consumer Updates "Light" Tobacco Products Pose Heavy Health Risks Share Tweet ... Feed A federal law is restricting the words “light,” “low,” and “mild” from tobacco products now on ...

  16. 'Button' Batteries Pose Serious Risk to Children

    MedlinePlus

    ... Drugs & Supplements Videos & Tools Español You Are Here: Home → Latest Health News → Article URL of this page: https://medlineplus.gov/news/fullstory_162950.html 'Button' Batteries Pose Serious Risk to Children Toddlers may swallow the tiny batteries used to power many common household objects ...

  17. Pose tracking for augmented reality applications in outdoor archaeological sites

    NASA Astrophysics Data System (ADS)

    Younes, Georges; Asmar, Daniel; Elhajj, Imad; Al-Harithy, Howayda

    2017-01-01

    In recent years, agencies around the world have invested huge amounts of effort toward digitizing many aspects of the world's cultural heritage. Of particular importance is the digitization of outdoor archaeological sites. In the spirit of valorization of this digital information, many groups have developed virtual or augmented reality (AR) computer applications themed around a particular archaeological object. The problem of pose tracking in outdoor AR applications is addressed. Different positional systems are analyzed, resulting in the selection of a monocular camera-based user tracker. The limitations that challenge this technique from map generation, scale, anchoring, to lighting conditions are analyzed and systematically addressed. Finally, as a case study, our pose tracking system is implemented within an AR experience in the Byblos Roman theater in Lebanon.

  18. Point Cloud Based Relative Pose Estimation of a Satellite in Close Range

    PubMed Central

    Liu, Lujiang; Zhao, Gaopeng; Bo, Yuming

    2016-01-01

    Determination of the relative pose of satellites is essential in space rendezvous operations and on-orbit servicing missions. The key problems are the adoption of suitable sensor on board of a chaser and efficient techniques for pose estimation. This paper aims to estimate the pose of a target satellite in close range on the basis of its known model by using point cloud data generated by a flash LIDAR sensor. A novel model based pose estimation method is proposed; it includes a fast and reliable pose initial acquisition method based on global optimal searching by processing the dense point cloud data directly, and a pose tracking method based on Iterative Closest Point algorithm. Also, a simulation system is presented in this paper in order to evaluate the performance of the sensor and generate simulated sensor point cloud data. It also provides truth pose of the test target so that the pose estimation error can be quantified. To investigate the effectiveness of the proposed approach and achievable pose accuracy, numerical simulation experiments are performed; results demonstrate algorithm capability of operating with point cloud directly and large pose variations. Also, a field testing experiment is conducted and results show that the proposed method is effective. PMID:27271633

  19. Point Cloud Based Relative Pose Estimation of a Satellite in Close Range.

    PubMed

    Liu, Lujiang; Zhao, Gaopeng; Bo, Yuming

    2016-06-04

    Determination of the relative pose of satellites is essential in space rendezvous operations and on-orbit servicing missions. The key problems are the adoption of suitable sensor on board of a chaser and efficient techniques for pose estimation. This paper aims to estimate the pose of a target satellite in close range on the basis of its known model by using point cloud data generated by a flash LIDAR sensor. A novel model based pose estimation method is proposed; it includes a fast and reliable pose initial acquisition method based on global optimal searching by processing the dense point cloud data directly, and a pose tracking method based on Iterative Closest Point algorithm. Also, a simulation system is presented in this paper in order to evaluate the performance of the sensor and generate simulated sensor point cloud data. It also provides truth pose of the test target so that the pose estimation error can be quantified. To investigate the effectiveness of the proposed approach and achievable pose accuracy, numerical simulation experiments are performed; results demonstrate algorithm capability of operating with point cloud directly and large pose variations. Also, a field testing experiment is conducted and results show that the proposed method is effective.

  20. Dismount Threat Recognition through Automatic Pose Identification

    DTIC Science & Technology

    2012-03-01

    camera and joint estimation software of the Kinect for Xbox 360. A threat determination is made based on the pose identified by the network. Ac- curacy...The automobile industry continues to refine pedestrian avoidance systems to assist drivers [14,15]. Microsoft’s Kinect for Xbox 360 [3] uses real-time...Conference on Acoustics, Speech and Signal Process- ing , Vol. 4, April 2007, pp. IV–21 – IV–24. 3. Kinect for Xbox 360 , Microsoft Corp., Redmond WA. 4

  1. Driver head pose tracking with thermal camera

    NASA Astrophysics Data System (ADS)

    Bole, S.; Fournier, C.; Lavergne, C.; Druart, G.; Lépine, T.

    2016-09-01

    Head pose can be seen as a coarse estimation of gaze direction. In automotive industry, knowledge about gaze direction could optimize Human-Machine Interface (HMI) and Advanced Driver Assistance Systems (ADAS). Pose estimation systems are often based on camera when applications have to be contactless. In this paper, we explore uncooled thermal imagery (8-14μm) for its intrinsic night vision capabilities and for its invariance versus lighting variations. Two methods are implemented and compared, both are aided by a 3D model of the head. The 3D model, mapped with thermal texture, allows to synthesize a base of 2D projected models, differently oriented and labeled in yaw and pitch. The first method is based on keypoints. Keypoints of models are matched with those of the query image. These sets of matchings, aided with the 3D shape of the model, allow to estimate 3D pose. The second method is a global appearance approach. Among all 2D models of the base, algorithm searches the one which is the closest to the query image thanks to a weighted least squares difference.

  2. A pose prediction approach based on ligand 3D shape similarity

    NASA Astrophysics Data System (ADS)

    Kumar, Ashutosh; Zhang, Kam Y. J.

    2016-06-01

    Molecular docking predicts the best pose of a ligand in the target protein binding site by sampling and scoring numerous conformations and orientations of the ligand. Failures in pose prediction are often due to either insufficient sampling or scoring function errors. To improve the accuracy of pose prediction by tackling the sampling problem, we have developed a method of pose prediction using shape similarity. It first places a ligand conformation of the highest 3D shape similarity with known crystal structure ligands into protein binding site and then refines the pose by repacking the side-chains and performing energy minimization with a Monte Carlo algorithm. We have assessed our method utilizing CSARdock 2012 and 2014 benchmark exercise datasets consisting of co-crystal structures from eight proteins. Our results revealed that ligand 3D shape similarity could substitute conformational and orientational sampling if at least one suitable co-crystal structure is available. Our method identified poses within 2 Å RMSD as the top-ranking pose for 85.7 % of the test cases. The median RMSD for our pose prediction method was found to be 0.81 Å and was better than methods performing extensive conformational and orientational sampling within target protein binding sites. Furthermore, our method was better than similar methods utilizing ligand 3D shape similarity for pose prediction.

  3. Tabu search for human pose recognition

    NASA Astrophysics Data System (ADS)

    Dyce, W.; Rodriguez, N.; Lange, B.; Andary, S.; Seilles, A.

    2014-03-01

    The use of computer vision techniques to build hands-free input devices has long been a topic of interest to researchers in the field of natural interaction. In recent years Microsoft's Kinect has brought these technologies to the layman, but the most commonly used libraries for Kinect human pose recognition are closed-source. There is not yet an accepted, effective open-source alternative upon which highly specific applications can be based. We propose a novel technique for extracting the appendage configurations of users from the Kinect camera's depth feed, based on stochastic local search techniques rather than per-pixel classification.

  4. Pose detection of a 3D object using template matched filtering

    NASA Astrophysics Data System (ADS)

    Picos, Kenia; Díaz-Ramírez, Víctor H.

    2016-09-01

    The problem of 3D pose recognition of a rigid object is difficult to solve because the pose in a 3D space can vary with multiple degrees of freedom. In this work, we propose an accurate method for 3D pose estimation based on template matched filtering. The proposed method utilizes a bank of space-variant filters which take into account different pose states of the target and local statistical properties of the input scene. The state parameters of location coordinates, orientation angles, and scaling parameters of the target are estimated with high accuracy in the input scene. Experimental tests are performed for real and synthetic scenes. The proposed system yields good performance for 3D pose recognition in terms of detection efficiency, location and orientation errors.

  5. Robotic-surgical instrument wrist pose estimation.

    PubMed

    Fabel, Stephan; Baek, Kyungim; Berkelman, Peter

    2010-01-01

    The Compact Lightweight Surgery Robot from the University of Hawaii includes two teleoperated instruments and one endoscope manipulator which act in accord to perform assisted interventional medicine. The relative positions and orientations of the robotic instruments and endoscope must be known to the teleoperation system so that the directions of the instrument motions can be controlled to correspond closely to the directions of the motions of the master manipulators, as seen by the the endoscope and displayed to the surgeon. If the manipulator bases are mounted in known locations and all manipulator joint variables are known, then the necessary coordinate transformations between the master and slave manipulators can be easily computed. The versatility and ease of use of the system can be increased, however, by allowing the endoscope or instrument manipulator bases to be moved to arbitrary positions and orientations without reinitializing each manipulator or remeasuring their relative positions. The aim of this work is to find the pose of the instrument end effectors using the video image from the endoscope camera. The P3P pose estimation algorithm is used with a Levenberg-Marquardt optimization to ensure convergence. The correct transformations between the master and slave coordinate frames can then be calculated and updated when the bases of the endoscope or instrument manipulators are moved to new, unknown, positions at any time before or during surgical procedures.

  6. Mrs. Chandrasekhar poses with contest winners

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Mrs. Lalitha Chandrasekhar (left), wife of the late Indian- American Nobel Laureate Subrahmanyan Chandrasekhar, poses with a model of the Chandra X-ray Observatory and the winners of the contest to rename the telescope in the TRW Media Hospitality Tent at the NASA Press Site at KSC. The winners of the contest are Jatila van der Veen (center), academic coordinator and lecturer, Physics Dept., University of Santa Barbara, Calif., and Tyrel Johnson (right), high school student, Laclede, Idaho. The name 'Chandra,' a shortened version of Chandrasekhar's name which he preferred among friends and colleagues, was chosen to honor the Nobel Laureate. 'Chandra' also means 'Moon' or 'luminous' in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93.

  7. Robust and Accurate Vision-Based Pose Estimation Algorithm Based on Four Coplanar Feature Points

    PubMed Central

    Zhang, Zimiao; Zhang, Shihai; Li, Qiu

    2016-01-01

    Vision-based pose estimation is an important application of machine vision. Currently, analytical and iterative methods are used to solve the object pose. The analytical solutions generally take less computation time. However, the analytical solutions are extremely susceptible to noise. The iterative solutions minimize the distance error between feature points based on 2D image pixel coordinates. However, the non-linear optimization needs a good initial estimate of the true solution, otherwise they are more time consuming than analytical solutions. Moreover, the image processing error grows rapidly with measurement range increase. This leads to pose estimation errors. All the reasons mentioned above will cause accuracy to decrease. To solve this problem, a novel pose estimation method based on four coplanar points is proposed. Firstly, the coordinates of feature points are determined according to the linear constraints formed by the four points. The initial coordinates of feature points acquired through the linear method are then optimized through an iterative method. Finally, the coordinate system of object motion is established and a method is introduced to solve the object pose. The growing image processing error causes pose estimation errors the measurement range increases. Through the coordinate system, the pose estimation errors could be decreased. The proposed method is compared with two other existing methods through experiments. Experimental results demonstrate that the proposed method works efficiently and stably. PMID:27999338

  8. Articulated Non-Rigid Point Set Registration for Human Pose Estimation from 3D Sensors

    PubMed Central

    Ge, Song; Fan, Guoliang

    2015-01-01

    We propose a generative framework for 3D human pose estimation that is able to operate on both individual point sets and sequential depth data. We formulate human pose estimation as a point set registration problem, where we propose three new approaches to address several major technical challenges in this research. First, we integrate two registration techniques that have a complementary nature to cope with non-rigid and articulated deformations of the human body under a variety of poses. This unique combination allows us to handle point sets of complex body motion and large pose variation without any initial conditions, as required by most existing approaches. Second, we introduce an efficient pose tracking strategy to deal with sequential depth data, where the major challenge is the incomplete data due to self-occlusions and view changes. We introduce a visible point extraction method to initialize a new template for the current frame from the previous frame, which effectively reduces the ambiguity and uncertainty during registration. Third, to support robust and stable pose tracking, we develop a segment volume validation technique to detect tracking failures and to re-initialize pose registration if needed. The experimental results on both benchmark 3D laser scan and depth datasets demonstrate the effectiveness of the proposed framework when compared with state-of-the-art algorithms. PMID:26131673

  9. Pose Estimation for Augmented Reality: A Hands-On Survey.

    PubMed

    Marchand, Eric; Uchiyama, Hideaki; Spindler, Fabien

    2016-12-01

    Augmented reality (AR) allows to seamlessly insert virtual objects in an image sequence. In order to accomplish this goal, it is important that synthetic elements are rendered and aligned in the scene in an accurate and visually acceptable way. The solution of this problem can be related to a pose estimation or, equivalently, a camera localization process. This paper aims at presenting a brief but almost self-contented introduction to the most important approaches dedicated to vision-based camera localization along with a survey of several extension proposed in the recent years. For most of the presented approaches, we also provide links to code of short examples. This should allow readers to easily bridge the gap between theoretical aspects and practical implementations.

  10. Gaze Estimation From Eye Appearance: A Head Pose-Free Method via Eye Image Synthesis.

    PubMed

    Lu, Feng; Sugano, Yusuke; Okabe, Takahiro; Sato, Yoichi

    2015-11-01

    In this paper, we address the problem of free head motion in appearance-based gaze estimation. This problem remains challenging because head motion changes eye appearance significantly, and thus, training images captured for an original head pose cannot handle test images captured for other head poses. To overcome this difficulty, we propose a novel gaze estimation method that handles free head motion via eye image synthesis based on a single camera. Compared with conventional fixed head pose methods with original training images, our method only captures four additional eye images under four reference head poses, and then, precisely synthesizes new training images for other unseen head poses in estimation. To this end, we propose a single-directional (SD) flow model to efficiently handle eye image variations due to head motion. We show how to estimate SD flows for reference head poses first, and then use them to produce new SD flows for training image synthesis. Finally, with synthetic training images, joint optimization is applied that simultaneously solves an eye image alignment and a gaze estimation. Evaluation of the method was conducted through experiments to assess its performance and demonstrate its effectiveness.

  11. Transfer between Pose and Illumination Training in Face Recognition

    ERIC Educational Resources Information Center

    Liu, Chang Hong; Bhuiyan, Md. Al-Amin; Ward, James; Sui, Jie

    2009-01-01

    The relationship between pose and illumination learning in face recognition was examined in a yes-no recognition paradigm. The authors assessed whether pose training can transfer to a new illumination or vice versa. Results show that an extensive level of pose training through a face-name association task was able to generalize to a new…

  12. Project Fox: Assessing Risks Posed By Asteroids

    NASA Astrophysics Data System (ADS)

    Reinhardt, J.; Chen, X.; Liu, W.; Manchev, P.; Paté-Cornell, M.

    2013-12-01

    In order to make decisions on how to invest limited research dollars on asteroid surveillance and mitigation options, an analytic understanding of the risks posed by impacts is necessary. Qualitative and quantitative studies have been performed to assess such risks, and some reasonable point estimates have been proposed. However, since consequential asteroid impacts tend to be rare events, point estimates and expected annual death rates do not adequately convey the heavy tail of the distribution, potentially leading to misguided resource allocations. We propose and develop a framework for new risk measures, including a distribution over the number of fatalities from asteroid impacts and the probability of a globally consequential impact. We implement a simulation of asteroid impacts using probabilistic inputs for impactor characteristics, and a Poisson process for asteroid arrivals over the next 100 years. Simulation results indicate that a significant portion of the risk to humans comes from asteroids in the 300-1000 meter diameter range; this is because asteroid impacts in this range can produce global effects, and are more frequent than those from asteroids greater than 1km in diameter. The relative importance of this size regime in overall asteroid impact risk is robust in simulation results, and we find the magnitude of risks is still sensitive to factors that contribute global effects from an asteroid impact. Initial results are provided on the sensitivity of impact risks to various mitigation measures, including 'civil defense' methods. These results underscore the need for next-generation survey missions, and can help provide the basis for setting future space telescope observation requirements.

  13. Using head poses to control a virtual robot walking in a virtualmaze

    NASA Astrophysics Data System (ADS)

    Zhao, Qingjie; Xu, Weicun; Wang, Yuxia; Shi, Xiaoming

    2013-05-01

    This paper develops a game system based on head pose identification techniques to control a virtual robot walking in a virtual maze environment built with Microsoft Robotics Developer Studio. Adaboost face classifiers are used to detect a face in the image and give a rough head pose classification. Two approaches are proposed to further determine more specific head poses. The first approach adopts PCA with nose template matching method, and the second one firstly uses a nose classifier to detect the nose in a detected face region and then directly utilizes the nose's relative position information to achieve head pose classification. A method to select the best nose area is proposed to solve the problem that multi-nose areas may be detected in one face region. Experiment results show that the two approaches have comparable time consumed, but the second approach provides more correct identification results.

  14. When a Problem Is More than a Teacher's Question

    ERIC Educational Resources Information Center

    Olson, Jo Clay; Knott, Libby

    2013-01-01

    Not only are the problems teachers pose throughout their teaching of great importance but also the ways in which they use those problems make this a critical component of teaching. A problem-posing episode includes the problem setup, the statement of the problem, and the follow-up questions. Analysis of problem-posing episodes of precalculus…

  15. Spatio-Temporal Matching for Human Pose Estimation in Video.

    PubMed

    Zhou, Feng; Torre, Fernando De la

    2016-08-01

    Detection and tracking humans in videos have been long-standing problems in computer vision. Most successful approaches (e.g., deformable parts models) heavily rely on discriminative models to build appearance detectors for body joints and generative models to constrain possible body configurations (e.g., trees). While these 2D models have been successfully applied to images (and with less success to videos), a major challenge is to generalize these models to cope with camera views. In order to achieve view-invariance, these 2D models typically require a large amount of training data across views that is difficult to gather and time-consuming to label. Unlike existing 2D models, this paper formulates the problem of human detection in videos as spatio-temporal matching (STM) between a 3D motion capture model and trajectories in videos. Our algorithm estimates the camera view and selects a subset of tracked trajectories that matches the motion of the 3D model. The STM is efficiently solved with linear programming, and it is robust to tracking mismatches, occlusions and outliers. To the best of our knowledge this is the first paper that solves the correspondence between video and 3D motion capture data for human pose detection. Experiments on the CMU motion capture, Human3.6M, Berkeley MHAD and CMU MAD databases illustrate the benefits of our method over state-of-the-art approaches.

  16. Pose Estimation with a Kinect for Ergonomic Studies: Evaluation of the Accuracy Using a Virtual Mannequin

    PubMed Central

    Plantard, Pierre; Auvinet, Edouard; Le Pierres, Anne-Sophie; Multon, Franck

    2015-01-01

    Analyzing human poses with a Kinect is a promising method to evaluate potentials risks of musculoskeletal disorders at workstations. In ecological situations, complex 3D poses and constraints imposed by the environment make it difficult to obtain reliable kinematic information. Thus, being able to predict the potential accuracy of the measurement for such complex 3D poses and sensor placements is challenging in classical experimental setups. To tackle this problem, we propose a new evaluation method based on a virtual mannequin. In this study, we apply this method to the evaluation of joint positions (shoulder, elbow, and wrist), joint angles (shoulder and elbow), and the corresponding RULA (a popular ergonomics assessment grid) upper-limb score for a large set of poses and sensor placements. Thanks to this evaluation method, more than 500,000 configurations have been automatically tested, which would be almost impossible to evaluate with classical protocols. The results show that the kinematic information obtained by the Kinect software is generally accurate enough to fill in ergonomic assessment grids. However inaccuracy strongly increases for some specific poses and sensor positions. Using this evaluation method enabled us to report configurations that could lead to these high inaccuracies. As a supplementary material, we provide a software tool to help designers to evaluate the expected accuracy of this sensor for a set of upper-limb configurations. Results obtained with the virtual mannequin are in accordance with those obtained from a real subject for a limited set of poses and sensor placements. PMID:25599426

  17. To Strike a Pose: No Stereotype Backlash for Power Posing Women

    PubMed Central

    Rennung, Miriam; Blum, Johannes; Göritz, Anja S.

    2016-01-01

    Power posing, the adoption of open and powerful postures, has effects that parallel those of actual social power. This study explored the social evaluation of adopting powerful vs. powerless body postures in men and women regarding perceived warmth, competence, and the likelihood of eliciting admiration, envy, pity, and contempt. Previous findings suggest that the display of power by women may have side effects due to gender stereotyping, namely reduced warmth ratings and negative emotional reactions. An experiment (N = 2,473) asked participants to rate pictures of men and women who adopted high-power or low-power body postures. High-power posers were rated higher on competence, admiration, envy, and contempt compared to low-power posers, whereas the opposite was true for pity. There was no impact of power posing on perceived warmth. Contrary to expectations, the poser’s gender did not moderate any of the effects. These findings suggest that non-verbal displays of power do influence fundamental dimensions of social perception and their accompanying emotional reactions but result in comparably positive and negative evaluations for both genders. PMID:27729887

  18. A Monocular SLAM Method to Estimate Relative Pose During Satellite Proximity Operations

    DTIC Science & Technology

    2015-03-26

    Research Projects Agency (DARPA), SpaceX , and Orbital Sciences Corporation aim to advance prox- ops technology and demonstrate capability to rendezvous...relative pose problem [11]. The SpaceX Dragon capsule and Cygnus by Orbital Sciences Corporation both send unmanned resupply capsules to the

  19. Face Recognition with Pose Variations and Misalignment via Orthogonal Procrustes Regression.

    PubMed

    Tai, Ying; Yang, Jian; Zhang, Yigong; Luo, Lei; Qian, Jianjun; Chen, Yu

    2016-04-06

    Linear regression based method is a hot topic in face recognition community. Recently, sparse representation and collaborative representation based classifiers for face recognition have been proposed and attracted great attention. However, most of the existing regression analysis based methods are sensitive to pose variations. In this paper, we introduce the orthogonal Procrustes problem (OPP) as a model to handle pose variations existed in two-dimensional face images. OPP seeks an optimal linear transformation between two images with different poses so as to make the transformed image best fits the other one. We integrate OPP into the regression model and propose the orthogonal Procrustes regression (OPR) model. To address the problem that the linear transformation is not suitable for handling highly non-linear pose variation, we further adopt a progressive strategy and propose the stacked orthogonal Procrustes regression (stacked OPR). As a practical framework, OPR can handle face alignment, pose correction and face representation simultaneously. We optimize the proposed model via an efficient alternating iterative algorithm and experimental results on three popular face databases, CMU PIE database, CMU Multi-PIE database and LFW database, demonstrate the effectiveness of our proposed method.

  20. Face Recognition With Pose Variations and Misalignment via Orthogonal Procrustes Regression.

    PubMed

    Tai, Ying; Yang, Jian; Zhang, Yigong; Luo, Lei; Qian, Jianjun; Chen, Yu

    2016-06-01

    A linear regression-based method is a hot topic in face recognition community. Recently, sparse representation and collaborative representation-based classifiers for face recognition have been proposed and attracted great attention. However, most of the existing regression analysis-based methods are sensitive to pose variations. In this paper, we introduce the orthogonal Procrustes problem (OPP) as a model to handle pose variations existed in 2D face images. OPP seeks an optimal linear transformation between two images with different poses so as to make the transformed image best fits the other one. We integrate OPP into the regression model and propose the orthogonal Procrustes regression (OPR) model. To address the problem that the linear transformation is not suitable for handling highly non-linear pose variation, we further adopt a progressive strategy and propose the stacked OPR. As a practical framework, OPR can handle face alignment, pose correction, and face representation simultaneously. We optimize the proposed model via an efficient alternating iterative algorithm, and experimental results on three popular face databases, such as CMU PIE database, CMU Multi-PIE database, and LFW database, demonstrate the effectiveness of our proposed method.

  1. Making faces: posed facial expression, self-competence, and personality.

    PubMed

    Browne, B A

    1994-03-01

    This study examined the relationships between posed facial expression, childrens' perceived self-competence, and teachers' perceptions of competence. Third- and fifth-grade children completed the Self-Perception Profile for Children, the Eysenck Personality Questionnaire, and the Junior Self-Monitoring Scale for Children. Individual differences in posing accuracy were determined with a videotaped acting task. Children who were more able to produce prototypical expressions obtained higher teacher ratings of academic competence; however, posing ability bore little relationship to children's self-competence. Gender differences in feelings of self-competence, but not in sending ability, were observed. Extraversion and self-monitoring were unrelated to ability to pose emotional expressions.

  2. The lighter side of advertising: investigating posing and lighting biases.

    PubMed

    Thomas, Nicole A; Burkitt, Jennifer A; Patrick, Regan E; Elias, Lorin J

    2008-11-01

    People tend to display the left cheek when posing for a portrait; however, this effect does not appear to generalise to advertising. The amount of body visible in the image and the sex of the poser might also contribute to the posing bias. Portraits also exhibit lateral lighting biases, with most images being lit from the left. This effect might also be present in advertisements. A total of 2801 full-page advertisements were sampled and coded for posing direction, lighting direction, sex of model, and amount of body showing. Images of females showed an overall leftward posing bias, but the biases in males depended on the amount of body visible. Males demonstrated rightward posing biases for head-only images. Overall, images tended to be lit from the top left corner. The two factors of posing and lighting biases appear to influence one another. Leftward-lit images had more leftward poses than rightward, while the opposite occurred for rightward-lit images. Collectively, these results demonstrate that the posing biases in advertisements are dependent on the amount of body showing in the image, and that biases in lighting direction interact with these posing biases.

  3. Troubles de la ménopause: enquête sur les connaissances, attitudes et pratiques du personnel des structures sanitaires de Dakar

    PubMed Central

    Diouf, Abdoul Aziz; Faye-Diémé, Marie Edouard; Guèye, Mamour; Sandjon, Tatiana Gisèle; Mbaye, Magatte; Moreau, Jean Charles; Diouf, Alassane

    2014-01-01

    Introduction Evaluer le niveau de connaissance du personnel de santé des structures sanitaires de la région de Dakar, l'attitude et les pratiques face aux troubles de la ménopause. Méthodes Enquête prospective auprès de 135 prestataires avec un questionnaire anonyme divisé en quatre rubriques: les caractéristiques socioprofessionnelles, les connaissances générales sur la ménopause, l'attitude et la pratique du prestataire par rapport à la ménopause troublée. Résultats Les prestataires de santé inclus dans l’étude étaient répartis comme suit: 11 gynécologues, 37 médecins en spécialisation gynécologique, 34 médecins généralistes et 53 sages-femmes d’état. L’âge moyen était de 35 ans. Le sexe féminin représentait 64% du groupe. Vingt et un pourcent des prestataires exerçaient depuis plus de 10 ans. De manière globale, les connaissances générales sur la ménopause étaient satisfaisantes du moment où la majeure partie des prestataires était en mesure de poser le diagnostic et de prévoir les conséquences du déficit hormonal. La majorité des prestataires (62%) était favorable au traitement de la ménopause troublée. Cependant, nous notons une certaine insuffisance dans le traitement de la ménopause, aussi bien dans le cadre de la thérapie hormonale que dans l'utilisation des moyens alternatifs. Conclusion Le nombre de femmes ménopausées augmente progressivement, et il convient de réunir toutes les stratégies de mise à niveau afin de faire face au défit de l'amélioration de la qualité de vie de cette catégorie de la population. PMID:25489362

  4. Comprendre l'influence des facteurs contextuels sur la participation communautaire à la santé : une étude de cas dans le district sanitaire de Tenkodogo, au Burkina Faso.

    PubMed

    Sombié, Issa; Ilboudo, David O S; Soubeiga, André Kamba; Samuelsen, Helle

    2015-08-07

    Le Burkina Faso met en œuvre depuis plusieurs années la stratégie de la participation communautaire. Des comités de gestion (CoGes) ont été mis en place dans les centres de santé de la première ligne et doivent participer aux prises de décisions. L'objectif principal de cette stratégie est de favoriser l'utilisation des services de santé et une adhésion massive des communautés aux activités de promotion de la santé. Seulement, on constate que les résultats escomptés par les autorités sanitaires tardent à se réaliser. Le présent article convoque les facteurs liés au contexte socioculturel du district sanitaire, pour analyser le phénomène de la participation communautaire.L'étude s'est déroulée dans le district sanitaire de Tenkodogo, situé dans la région administrative du Centre-est, à environ 190 km de la capitale. Cette étude exclusivement qualitative, a utilisé deux méthodes de collecte : les entretiens individuels et les focus groups. Les participants à l'étude sont les chefs de ménage (n = 48), les membres des CoGes (n = 10), les agents de santé (n = 8) et les agents de santé communautaire (n = 24). La méthode de l'analyse de contenu a été utilisée pour l'analyse des données.Les résultats de l'étude montrent que plusieurs facteurs socioculturels influencent la dynamique de la participation communautaire dans le district. Ce sont les conditions économiques, la perception négative des services de santé, les inégalités sociales de sexe et d'âge, le faible ancrage social des organisations communautaires, les rivalités inter-villages et les conflits coutumiers. L'étude relève également que les communautés ne perçoivent pas leur implication dans le processus décisionnel des services de santé comme une priorité. Leurs principales attentes s'orientent vers la disponibilité de soins de qualité et à coût réduit.

  5. Binding Pose Flip Explained via Enthalpic and Entropic Contributions

    PubMed Central

    2017-01-01

    The anomalous binding modes of five highly similar fragments of TIE2 inhibitors, showing three distinct binding poses, are investigated. We report a quantitative rationalization for the changes in binding pose based on molecular dynamics simulations. We investigated five fragments in complex with the transforming growth factor β receptor type 1 kinase domain. Analyses of these simulations using Grid Inhomogeneous Solvation Theory (GIST), pKA calculations, and a tool to investigate enthalpic differences upon binding unraveled the various thermodynamic contributions to the different binding modes. While one binding mode flip can be rationalized by steric repulsion, the second binding pose flip revealed a different protonation state for one of the ligands, leading to different enthalpic and entropic contributions to the binding free energy. One binding pose is stabilized by the displacement of entropically unfavored water molecules (binding pose determined by solvation entropy), ligands in the other binding pose are stabilized by strong enthalpic interactions, overcompensating the unfavorable water entropy in this pose (binding pose determined by enthalpic interactions). This analysis elucidates unprecedented details determining the flipping of the binding modes, which can elegantly explain the experimental findings for this system. PMID:28079371

  6. A Survey on Model Based Approaches for 2D and 3D Visual Human Pose Recovery

    PubMed Central

    Perez-Sala, Xavier; Escalera, Sergio; Angulo, Cecilio; Gonzàlez, Jordi

    2014-01-01

    Human Pose Recovery has been studied in the field of Computer Vision for the last 40 years. Several approaches have been reported, and significant improvements have been obtained in both data representation and model design. However, the problem of Human Pose Recovery in uncontrolled environments is far from being solved. In this paper, we define a general taxonomy to group model based approaches for Human Pose Recovery, which is composed of five main modules: appearance, viewpoint, spatial relations, temporal consistence, and behavior. Subsequently, a methodological comparison is performed following the proposed taxonomy, evaluating current SoA approaches in the aforementioned five group categories. As a result of this comparison, we discuss the main advantages and drawbacks of the reviewed literature. PMID:24594613

  7. Generalized Hough transform based time invariant action recognition with 3D pose information

    NASA Astrophysics Data System (ADS)

    Muench, David; Huebner, Wolfgang; Arens, Michael

    2014-10-01

    Human action recognition has emerged as an important field in the computer vision community due to its large number of applications such as automatic video surveillance, content based video-search and human robot interaction. In order to cope with the challenges that this large variety of applications present, recent research has focused more on developing classifiers able to detect several actions in more natural and unconstrained video sequences. The invariance discrimination tradeoff in action recognition has been addressed by utilizing a Generalized Hough Transform. As a basis for action representation we transform 3D poses into a robust feature space, referred to as pose descriptors. For each action class a one-dimensional temporal voting space is constructed. Votes are generated from associating pose descriptors with their position in time relative to the end of an action sequence. Training data consists of manually segmented action sequences. In the detection phase valid human 3D poses are assumed as input, e.g. originating from 3D sensors or monocular pose reconstruction methods. The human 3D poses are normalized to gain view-independence and transformed into (i) relative limb-angle space to ensure independence of non-adjacent joints or (ii) geometric features. In (i) an action descriptor consists of the relative angles between limbs and their temporal derivatives. In (ii) the action descriptor consists of different geometric features. In order to circumvent the problem of time-warping we propose to use a codebook of prototypical 3D poses which is generated from sample sequences of 3D motion capture data. This idea is in accordance with the concept of equivalence classes in action space. Results of the codebook method are presented using the Kinect sensor and the CMU Motion Capture Database.

  8. A Bayesian framework for human body pose tracking from depth image sequences.

    PubMed

    Zhu, Youding; Fujimura, Kikuo

    2010-01-01

    This paper addresses the problem of accurate and robust tracking of 3D human body pose from depth image sequences. Recovering the large number of degrees of freedom in human body movements from a depth image sequence is challenging due to the need to resolve the depth ambiguity caused by self-occlusions and the difficulty to recover from tracking failure. Human body poses could be estimated through model fitting using dense correspondences between depth data and an articulated human model (local optimization method). Although it usually achieves a high accuracy due to dense correspondences, it may fail to recover from tracking failure. Alternately, human pose may be reconstructed by detecting and tracking human body anatomical landmarks (key-points) based on low-level depth image analysis. While this method (key-point based method) is robust and recovers from tracking failure, its pose estimation accuracy depends solely on image-based localization accuracy of key-points. To address these limitations, we present a flexible Bayesian framework for integrating pose estimation results obtained by methods based on key-points and local optimization. Experimental results are shown and performance comparison is presented to demonstrate the effectiveness of the proposed approach.

  9. Pose-free structure from motion using depth from motion constraints.

    PubMed

    Zhang, Ji; Boutin, Mireille; Aliaga, Daniel G

    2011-10-01

    Structure from motion (SFM) is the problem of recovering the geometry of a scene from a stream of images taken from unknown viewpoints. One popular approach to estimate the geometry of a scene is to track scene features on several images and reconstruct their position in 3-D. During this process, the unknown camera pose must also be recovered. Unfortunately, recovering the pose can be an ill-conditioned problem which, in turn, can make the SFM problem difficult to solve accurately. We propose an alternative formulation of the SFM problem with fixed internal camera parameters known a priori. In this formulation, obtained by algebraic variable elimination, the external camera pose parameters do not appear. As a result, the problem is better conditioned in addition to involving much fewer variables. Variable elimination is done in three steps. First, we take the standard SFM equations in projective coordinates and eliminate the camera orientations from the equations. We then further eliminate the camera center positions. Finally, we also eliminate all 3-D point positions coordinates, except for their depths with respect to the camera center, thus obtaining a set of simple polynomial equations of degree two and three. We show that, when there are merely a few points and pictures, these "depth-only equations" can be solved in a global fashion using homotopy methods. We also show that, in general, these same equations can be used to formulate a pose-free cost function to refine SFM solutions in a way that is more accurate than by minimizing the total reprojection error, as done when using the bundle adjustment method. The generalization of our approach to the case of varying internal camera parameters is briefly discussed.

  10. Space vehicle pose estimation via optical correlation and nonlinear estimation

    NASA Astrophysics Data System (ADS)

    Rakoczy, John M.; Herren, Kenneth A.

    2008-03-01

    A technique for 6-degree-of-freedom (6DOF) pose estimation of space vehicles is being developed. This technique draws upon recent developments in implementing optical correlation measurements in a nonlinear estimator, which relates the optical correlation measurements to the pose states (orientation and position). For the optical correlator, the use of both conjugate filters and binary, phase-only filters in the design of synthetic discriminant function (SDF) filters is explored. A static neural network is trained a priori and used as the nonlinear estimator. New commercial animation and image rendering software is exploited to design the SDF filters and to generate a large filter set with which to train the neural network. The technique is applied to pose estimation for rendezvous and docking of free-flying spacecraft and to terrestrial surface mobility systems for NASA's Vision for Space Exploration. Quantitative pose estimation performance will be reported. Advantages and disadvantages of the implementation of this technique are discussed.

  11. 32. BUCKET POSING OVER CARGO HOLD; NOTE OPERATOR OVER BUCKET. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. BUCKET POSING OVER CARGO HOLD; NOTE OPERATOR OVER BUCKET. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  12. Health Issues: Do Cell Phones Pose a Health Hazard?

    MedlinePlus

    ... Procedures Home, Business, and Entertainment Products Cell Phones Health Issues Share Tweet Linkedin Pin it More sharing ... it Email Print Do cell phones pose a health hazard? Many people are concerned that cell phone ...

  13. The Risks that Foreign Labor Poses to UAE National Security

    DTIC Science & Technology

    2012-06-08

    AND SUBTITLE The Risks that Foreign Labor poses to UAE National Security 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6......69 viii APPENDIX C INTERNATIONAL CONVENTION FOR THE PROTECTION OF MIGRANT WORKERS’ RIGHTS

  14. Space Vehicle Pose Estimation via Optical Correlation and Nonlinear Estimation

    NASA Technical Reports Server (NTRS)

    Rakoczy, John; Herren, Kenneth

    2007-01-01

    A technique for 6-degree-of-freedom (6DOF) pose estimation of space vehicles is being developed. This technique draws upon recent developments in implementing optical correlation measurements in a nonlinear estimator, which relates the optical correlation measurements to the pose states (orientation and position). For the optical correlator, the use of both conjugate filters and binary, phase-only filters in the design of synthetic discriminant function (SDF) filters is explored. A static neural network is trained a priori and used as the nonlinear estimator. New commercial animation and image rendering software is exploited to design the SDF filters and to generate a large filter set with which to train the neural network. The technique is applied to pose estimation for rendezvous and docking of free-flying spacecraft and to terrestrial surface mobility systems for NASA's Vision for Space Exploration. Quantitative pose estimation performance will be reported. Advantages and disadvantages of the implementation of this technique are discussed.

  15. Space Vehicle Pose Estimation via Optical Correlation and Nonlinear Estimation

    NASA Technical Reports Server (NTRS)

    Rakoczy, John M.; Herren, Kenneth A.

    2008-01-01

    A technique for 6-degree-of-freedom (6DOF) pose estimation of space vehicles is being developed. This technique draws upon recent developments in implementing optical correlation measurements in a nonlinear estimator, which relates the optical correlation measurements to the pose states (orientation and position). For the optical correlator, the use of both conjugate filters and binary, phase-only filters in the design of synthetic discriminant function (SDF) filters is explored. A static neural network is trained a priori and used as the nonlinear estimator. New commercial animation and image rendering software is exploited to design the SDF filters and to generate a large filter set with which to train the neural network. The technique is applied to pose estimation for rendezvous and docking of free-flying spacecraft and to terrestrial surface mobility systems for NASA's Vision for Space Exploration. Quantitative pose estimation performance will be reported. Advantages and disadvantages of the implementation of this technique are discussed.

  16. Hold That Pose: Yoga May Ease Tough Depression

    MedlinePlus

    ... html Hold That Pose: Yoga May Ease Tough Depression Study finds weekly sessions, plus deep breathing, helped ... the doctor ordered when it comes to beating depression, new research suggests. Researchers found that weekly sessions ...

  17. 11. Photocopied July 1978. (QMC) GROUP SHOT OF WORKERS POSED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photocopied July 1978. (QMC) GROUP SHOT OF WORKERS POSED WITH NO. 2 SHAFT-ROCKHOUSE IN BACKGROUND. NOTE THE LONE WOMAN IN THE PHOTO. C. 1895-1905. - Quincy Mining Company, Hancock, Houghton County, MI

  18. Joint albedo estimation and pose tracking from video.

    PubMed

    Taheri, Sima; Sankaranarayanan, Aswin C; Chellappa, Rama

    2013-07-01

    The albedo of a Lambertian object is a surface property that contributes to an object's appearance under changing illumination. As a signature independent of illumination, the albedo is useful for object recognition. Single image-based albedo estimation algorithms suffer due to shadows and non-Lambertian effects of the image. In this paper, we propose a sequential algorithm to estimate the albedo from a sequence of images of a known 3D object in varying poses and illumination conditions. We first show that by knowing/estimating the pose of the object at each frame of a sequence, the object's albedo can be efficiently estimated using a Kalman filter. We then extend this for the case of unknown pose by simultaneously tracking the pose as well as updating the albedo through a Rao-Blackwellized particle filter (RBPF). More specifically, the albedo is marginalized from the posterior distribution and estimated analytically using the Kalman filter, while the pose parameters are estimated using importance sampling and by minimizing the projection error of the face onto its spherical harmonic subspace, which results in an illumination-insensitive pose tracking algorithm. Illustrations and experiments are provided to validate the effectiveness of the approach using various synthetic and real sequences followed by applications to unconstrained, video-based face recognition.

  19. Are predefined decoy sets of ligand poses able to quantify scoring function accuracy?

    NASA Astrophysics Data System (ADS)

    Korb, Oliver; ten Brink, Tim; Victor Paul Raj, Fredrick Robin Devadoss; Keil, Matthias; Exner, Thomas E.

    2012-02-01

    Due to the large number of different docking programs and scoring functions available, researchers are faced with the problem of selecting the most suitable one when starting a structure-based drug discovery project. To guide the decision process, several studies comparing different docking and scoring approaches have been published. In the context of comparing scoring function performance, it is common practice to use a predefined, computer-generated set of ligand poses (decoys) and to reevaluate their score using the set of scoring functions to be compared. But are predefined decoy sets able to unambiguously evaluate and rank different scoring functions with respect to pose prediction performance? This question arose when the pose prediction performance of our piecewise linear potential derived scoring functions (Korb et al. in J Chem Inf Model 49:84-96, 2009) was assessed on a standard decoy set (Cheng et al. in J Chem Inf Model 49:1079-1093, 2009). While they showed excellent pose identification performance when they were used for rescoring of the predefined decoy conformations, a pronounced degradation in performance could be observed when they were directly applied in docking calculations using the same test set. This implies that on a discrete set of ligand poses only the rescoring performance can be evaluated. For comparing the pose prediction performance in a more rigorous manner, the search space of each scoring function has to be sampled extensively as done in the docking calculations performed here. We were able to identify relative strengths and weaknesses of three scoring functions (ChemPLP, GoldScore, and Astex Statistical Potential) by analyzing the performance for subsets of the complexes grouped by different properties of the active site. However, reasons for the overall poor performance of all three functions on this test set compared to other test sets of similar size could not be identified.

  20. Multi-object segmentation using coupled nonparametric shape and relative pose priors

    NASA Astrophysics Data System (ADS)

    Uzunbas, Mustafa Gökhan; Soldea, Octavian; Çetin, Müjdat; Ünal, Gözde; Erçil, Aytül; Unay, Devrim; Ekin, Ahmet; Firat, Zeynep

    2009-02-01

    We present a new method for multi-object segmentation in a maximum a posteriori estimation framework. Our method is motivated by the observation that neighboring or coupling objects in images generate configurations and co-dependencies which could potentially aid in segmentation if properly exploited. Our approach employs coupled shape and inter-shape pose priors that are computed using training images in a nonparametric multi-variate kernel density estimation framework. The coupled shape prior is obtained by estimating the joint shape distribution of multiple objects and the inter-shape pose priors are modeled via standard moments. Based on such statistical models, we formulate an optimization problem for segmentation, which we solve by an algorithm based on active contours. Our technique provides significant improvements in the segmentation of weakly contrasted objects in a number of applications. In particular for medical image analysis, we use our method to extract brain Basal Ganglia structures, which are members of a complex multi-object system posing a challenging segmentation problem. We also apply our technique to the problem of handwritten character segmentation. Finally, we use our method to segment cars in urban scenes.

  1. Surgical fiducial segmentation and tracking for pose estimation based on ultrasound B-mode images.

    PubMed

    Lei Chen; Kuo, Nathanael; Aalamifar, Fereshteh; Narrow, David; Coon, Devin; Prince, Jerry; Boctor, Emad M

    2016-08-01

    Doppler ultrasound is a non-invasive diagnostic tool for the quantitative measurement of blood flow. However, given that it provides velocity data that is dependent on the location and angle of measurement, repeat measurements to detect problems over time may require an expert to return to the same location. We therefore developed an image-guidance system based on ultrasound B-mode images that enables an inexperienced user to position the ultrasound probe at the same site repeatedly in order to acquire a comparable time series of Doppler readings. The system utilizes a bioresorbable fiducial and complementing software composed of the fiducial detection, key points tracking, probe pose estimation, and graphical user interface (GUI) modules. The fiducial is an echogenic marker that is implanted at the surgical site and can be detected and tracked during ultrasound B-mode screening. The key points on the marker can next be used to determine the pose of the ultrasound probe with respect to the marker. The 3D representation of the probe with its position and orientation are then displayed in the GUI for the user guidance. The fiducial detection has been tested on the data sets collected from three animal studies. The pose estimation algorithm was validated by five data sets collected by a UR5 robot. We tested the system on a plastisol phantom and showed that it can detect and track the fiducial marker while displaying the probe pose in real-time.

  2. Effects of protein conformation in docking: improved pose prediction through protein pocket adaptation

    NASA Astrophysics Data System (ADS)

    Jain, Ajay N.

    2009-06-01

    Computational methods for docking ligands have been shown to be remarkably dependent on precise protein conformation, where acceptable results in pose prediction have been generally possible only in the artificial case of re-docking a ligand into a protein binding site whose conformation was determined in the presence of the same ligand (the "cognate" docking problem). In such cases, on well curated protein/ligand complexes, accurate dockings can be returned as top-scoring over 75% of the time using tools such as Surflex-Dock. A critical application of docking in modeling for lead optimization requires accurate pose prediction for novel ligands, ranging from simple synthetic analogs to very different molecular scaffolds. Typical results for widely used programs in the "cross-docking case" (making use of a single fixed protein conformation) have rates closer to 20% success. By making use of protein conformations from multiple complexes, Surflex-Dock yields an average success rate of 61% across eight pharmaceutically relevant targets. Following docking, protein pocket adaptation and rescoring identifies single pose families that are correct an average of 67% of the time. Consideration of the best of two pose families (from alternate scoring regimes) yields a 75% mean success rate.

  3. Effects of protein conformation in docking: improved pose prediction through protein pocket adaptation.

    PubMed

    Jain, Ajay N

    2009-06-01

    Computational methods for docking ligands have been shown to be remarkably dependent on precise protein conformation, where acceptable results in pose prediction have been generally possible only in the artificial case of re-docking a ligand into a protein binding site whose conformation was determined in the presence of the same ligand (the "cognate" docking problem). In such cases, on well curated protein/ligand complexes, accurate dockings can be returned as top-scoring over 75% of the time using tools such as Surflex-Dock. A critical application of docking in modeling for lead optimization requires accurate pose prediction for novel ligands, ranging from simple synthetic analogs to very different molecular scaffolds. Typical results for widely used programs in the "cross-docking case" (making use of a single fixed protein conformation) have rates closer to 20% success. By making use of protein conformations from multiple complexes, Surflex-Dock yields an average success rate of 61% across eight pharmaceutically relevant targets. Following docking, protein pocket adaptation and rescoring identifies single pose families that are correct an average of 67% of the time. Consideration of the best of two pose families (from alternate scoring regimes) yields a 75% mean success rate.

  4. Particle Filters and Occlusion Handling for Rigid 2D-3D Pose Tracking

    PubMed Central

    Lee, Jehoon; Sandhu, Romeil; Tannenbaum, Allen

    2013-01-01

    In this paper, we address the problem of 2D-3D pose estimation. Specifically, we propose an approach to jointly track a rigid object in a 2D image sequence and to estimate its pose (position and orientation) in 3D space. We revisit a joint 2D segmentation/3D pose estimation technique, and then extend the framework by incorporating a particle filter to robustly track the object in a challenging environment, and by developing an occlusion detection and handling scheme to continuously track the object in the presence of occlusions. In particular, we focus on partial occlusions that prevent the tracker from extracting an exact region properties of the object, which plays a pivotal role for region-based tracking methods in maintaining the track. To this end, a dynamical choice of how to invoke the objective functional is performed online based on the degree of dependencies between predictions and measurements of the system in accordance with the degree of occlusion and the variation of the object’s pose. This scheme provides the robustness to deal with occlusions of an obstacle with different statistical properties from that of the object of interest. Experimental results demonstrate the practical applicability and robustness of the proposed method in several challenging scenarios. PMID:24058277

  5. Preparatory power posing affects nonverbal presence and job interview performance.

    PubMed

    Cuddy, Amy J C; Wilmuth, Caroline A; Yap, Andy J; Carney, Dana R

    2015-07-01

    The authors tested whether engaging in expansive (vs. contractive) "power poses" before a stressful job interview--preparatory power posing--would enhance performance during the interview. Participants adopted high-power (i.e., expansive, open) poses or low-power (i.e., contractive, closed) poses, and then prepared and delivered a speech to 2 evaluators as part of a mock job interview. All interview speeches were videotaped and coded for overall performance and hireability and for 2 potential mediators: verbal content (e.g., structure, content) and nonverbal presence (e.g., captivating, enthusiastic). As predicted, those who prepared for the job interview with high- (vs. low-) power poses performed better and were more likely to be chosen for hire; this relation was mediated by nonverbal presence, but not by verbal content. Although previous research has focused on how a nonverbal behavior that is enacted during interactions and observed by perceivers affects how those perceivers evaluate and respond to the actor, this experiment focused on how a nonverbal behavior that is enacted before the interaction and unobserved by perceivers affects the actor's performance, which, in turn, affects how perceivers evaluate and respond to the actor. This experiment reveals a theoretically novel and practically informative result that demonstrates the causal relation between preparatory nonverbal behavior and subsequent performance and outcomes.

  6. Learning a Tracking and Estimation Integrated Graphical Model for Human Pose Tracking.

    PubMed

    Zhao, Lin; Gao, Xinbo; Tao, Dacheng; Li, Xuelong

    2015-12-01

    We investigate the tracking of 2-D human poses in a video stream to determine the spatial configuration of body parts in each frame, but this is not a trivial task because people may wear different kinds of clothing and may move very quickly and unpredictably. The technology of pose estimation is typically applied, but it ignores the temporal context and cannot provide smooth, reliable tracking results. Therefore, we develop a tracking and estimation integrated model (TEIM) to fully exploit temporal information by integrating pose estimation with visual tracking. However, joint parsing of multiple articulated parts over time is difficult, because a full model with edges capturing all pairwise relationships within and between frames is loopy and intractable. In previous models, approximate inference was usually resorted to, but it cannot promise good results and the computational cost is large. We overcome these problems by exploring the idea of divide and conquer, which decomposes the full model into two much simpler tractable submodels. In addition, a novel two-step iteration strategy is proposed to efficiently conquer the joint parsing problem. Algorithmically, we design TEIM very carefully so that: 1) it enables pose estimation and visual tracking to compensate for each other to achieve desirable tracking results; 2) it is able to deal with the problem of tracking loss; and 3) it only needs past information and is capable of tracking online. Experiments are conducted on two public data sets in the wild with ground truth layout annotations, and the experimental results indicate the effectiveness of the proposed TEIM framework.

  7. Vision based object pose estimation for mobile robots

    NASA Technical Reports Server (NTRS)

    Wu, Annie; Bidlack, Clint; Katkere, Arun; Feague, Roy; Weymouth, Terry

    1994-01-01

    Mobile robot navigation using visual sensors requires that a robot be able to detect landmarks and obtain pose information from a camera image. This paper presents a vision system for finding man-made markers of known size and calculating the pose of these markers. The algorithm detects and identifies the markers using a weighted pattern matching template. Geometric constraints are then used to calculate the position of the markers relative to the robot. The selection of geometric constraints comes from the typical pose of most man-made signs, such as the sign standing vertical and the dimensions of known size. This system has been tested successfully on a wide range of real images. Marker detection is reliable, even in cluttered environments, and under certain marker orientations, estimation of the orientation has proven accurate to within 2 degrees, and distance estimation to within 0.3 meters.

  8. Viewpoint and pose in body-form adaptation.

    PubMed

    Sekunova, Alla; Black, Michael; Parkinson, Laura; Barton, Jason J S

    2013-01-01

    Faces and bodies are complex structures, perception of which can play important roles in person identification and inference of emotional state. Face representations have been explored using behavioural adaptation: in particular, studies have shown that face aftereffects show relatively broad tuning for viewpoint, consistent with origin in a high-level structural descriptor far removed from the retinal image. Our goals were to determine first, if body aftereffects also showed a degree of viewpoint invariance, and second if they also showed pose invariance, given that changes in pose create even more dramatic changes in the 2-D retinal image. We used a 3-D model of the human body to generate headless body images, whose parameters could be varied to generate different body forms, viewpoints, and poses. In the first experiment, subjects adapted to varying viewpoints of either slim or heavy bodies in a neutral stance, followed by test stimuli that were all front-facing. In the second experiment, we used the same front-facing bodies in neutral stance as test stimuli, but compared adaptation from bodies in the same neutral stance to adaptation with the same bodies in different poses. We found that body aftereffects were obtained over substantial viewpoint changes, with no significant decline in aftereffect magnitude with increasing viewpoint difference between adapting and test images. Aftereffects also showed transfer across one change in pose but not across another. We conclude that body representations may have more viewpoint invariance than faces, and demonstrate at least some transfer across pose, consistent with a high-level structural description.

  9. Pose-Encoded Spherical Harmonics for Face Recognition and Synthesis Using a Single Image

    NASA Astrophysics Data System (ADS)

    Yue, Zhanfeng; Zhao, Wenyi; Chellappa, Rama

    2007-12-01

    Face recognition under varying pose is a challenging problem, especially when illumination variations are also present. In this paper, we propose to address one of the most challenging scenarios in face recognition. That is, to identify a subject from a test image that is acquired under different pose and illumination condition from only one training sample (also known as a gallery image) of this subject in the database. For example, the test image could be semifrontal and illuminated by multiple lighting sources while the corresponding training image is frontal under a single lighting source. Under the assumption of Lambertian reflectance, the spherical harmonics representation has proved to be effective in modeling illumination variations for a fixed pose. In this paper, we extend the spherical harmonics representation to encode pose information. More specifically, we utilize the fact that 2D harmonic basis images at different poses are related by close-form linear transformations, and give a more convenient transformation matrix to be directly used for basis images. An immediate application is that we can easily synthesize a different view of a subject under arbitrary lighting conditions by changing the coefficients of the spherical harmonics representation. A more important result is an efficient face recognition method, based on the orthonormality of the linear transformations, for solving the above-mentioned challenging scenario. Thus, we directly project a nonfrontal view test image onto the space of frontal view harmonic basis images. The impact of some empirical factors due to the projection is embedded in a sparse warping matrix; for most cases, we show that the recognition performance does not deteriorate after warping the test image to the frontal view. Very good recognition results are obtained using this method for both synthetic and challenging real images.

  10. Pregnancy-Linked Diabetes Poses Risks for Mom, Baby

    MedlinePlus

    ... Español You Are Here: Home → Latest Health News → Article URL of this page: https://medlineplus.gov/news/fullstory_163632.html Pregnancy-Linked Diabetes Poses Risks for Mom, Baby Study confirms numerous hazards, and experts stress the condition must be treated immediately To use ...

  11. Lessons about Climate Change Pose Many Challenges for Science Teachers

    ERIC Educational Resources Information Center

    Cavanagh, Sean

    2007-01-01

    This article reports on lessons about climate change which pose many challenges for science teachers. The natural world today offers a broad--and dire--catalog of scientific phenomena for teachers wanting to craft classroom lessons on the topic of climate change. As public concern about global warming increases, teachers are carving out a larger…

  12. Online Professors Pose as Students to Encourage Real Learning

    ERIC Educational Resources Information Center

    Parry, Marc

    2009-01-01

    Some professors of online courses are posing as students, infiltrating online course to collect information about students by blending in with them. The deceit has provoked questions about faculty ethics. Two professors admit that their unreal students teeter on an ethical precipice, because the technique could be abused. Others in the…

  13. Astronaut Linda Godwin poses with spacesuit she wore for launch

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Astronaut Linda M. Godwin, STS-59 payload commander, poses with the spacesuit she wore for launch. She will eventually wear the partial pressure suit for the entry phase of the Space Shuttle Endeavour's week and a half mission in Earth orbit.

  14. Child Deaths Highlight Choking Dangers Posed by Grapes

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_162679.html Child Deaths Highlight Choking Dangers Posed by Grapes Deaths of 5-year-old and toddler cited in ... 2016 (HealthDay News) -- Young children can choke to death on whole grapes, warn the authors of a ...

  15. UAV to UAV Target Detection and Pose Estimation

    DTIC Science & Technology

    2012-06-01

    using real-life data sets. UAV detection, Pose estimation, Computer Vision, Obstacle Avoidance, Edge Detection, Morphological Filtering. Unclassified...22 Figure 3.3 Light Beacon Design . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Figure 3.4 Basic Morphological Operations...26 Figure 3.5 Advanced Morphological Operations . . . . . . . . . . . . . . . . . . 26 Figure 3.6 Frame Grabbing

  16. Optical neural network system for pose determination of spinning satellites

    NASA Technical Reports Server (NTRS)

    Lee, Andrew; Casasent, David

    1990-01-01

    An optical neural network architecture and algorithm based on a Hopfield optimization network are presented for multitarget tracking. This tracker utilizes a neuron for every possible target track, and a quadratic energy function of neural activities which is minimized using gradient descent neural evolution. The neural net tracker is demonstrated as part of a system for determining position and orientation (pose) of spinning satellites with respect to a robotic spacecraft. The input to the system is time sequence video from a single camera. Novelty detection and filtering are utilized to locate and segment novel regions from the input images. The neural net multitarget tracker determines the correspondences (or tracks) of the novel regions as a function of time, and hence the paths of object (satellite) parts. The path traced out by a given part or region is approximately elliptical in image space, and the position, shape and orientation of the ellipse are functions of the satellite geometry and its pose. Having a geometric model of the satellite, and the elliptical path of a part in image space, the three-dimensional pose of the satellite is determined. Digital simulation results using this algorithm are presented for various satellite poses and lighting conditions.

  17. 43. Historic photo of Bruce Lundin posing in front of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    43. Historic photo of Bruce Lundin posing in front of observation window in exhaust cone at base of test stand A in Building 202, September 1960. On file at NASA Plumbrook Research Center, Sandusky, Ohio. NASA photo number C-53170. - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

  18. Optical neural network system for pose determination of spinning satellites

    NASA Astrophysics Data System (ADS)

    Lee, Andrew J.; Casasent, David P.

    1990-09-01

    An optical neural network architecture and algorithm based on a Hopfield optimization network are presented for multitarget tracking. This tracker utilizes a neuron for every possible target track and a quadratic energy function of neural activities which is minimized using gradient descent neural evolution. The neural net tracker is demonstrated as part of a system for determining position and orientation (pose) of spinning sateffites with respect to a robotic spacecraft. The input to the system is time sequence video from a single camera. Novelty detection and filtering are utilized to locate and segment novel regions from the input images. The neural net multitarget tracker determines the correspondences (or tracks) of the novel regions as a function of time and hence the paths of object (sateffite) parts. The path traced out by a given part or region is approximately elliptical in image space and the position shape and orientation of the ellipse are functions of the satellite geometry and its pose. Having a geometric model of the satellite and the effiptical path of a part in image space the 3-D pose of the satellite is determined. Digital simulation results using this algorithm are presented for various sateffite poses and lighting conditions. 1

  19. Pose Estimation from Line Correspondences: A Complete Analysis and A Series of Solutions.

    PubMed

    Xu, Chi; Zhang, Lilian; Cheng, Li; Koch, Reinhard

    2016-06-20

    In this paper we deal with the camera pose estimation problem from a set of 2D/3D line correspondences, which is also known as PnL (Perspective-n-Line) problem. We carry out our study by comparing PnL with the well-studied PnP (Perspective-n-Point) problem, and our contributions are threefold: (1) We provide a complete 3D configuration analysis for P3L, which includes the well-known P3P problem as well as several existing analyses as special cases. (2) By exploring the similarity between PnL and PnP, we propose a new subset-based PnL approach as well as a series of linear-formulation-based PnL approaches inspired by their PnP counterparts. (3) The proposed linear-formulation-based methods can be easily extended to deal with the line and point features simultaneously.

  20. Face recognition with illumination and pose variations using MINACE filters

    NASA Astrophysics Data System (ADS)

    Casasent, David; Patnaik, Rohit

    2005-10-01

    This paper presents the status of our present CMU face recognition work. We first present a face recognition system that functions in the presence of illumination variations. We then present initial results when pose variations are also considered. A separate minimum noise and correlation energy (MINACE) filter is synthesized for each person. Our concern is face identification and impostor (non-database face) rejection. Most prior face identification did not address impostor rejection. We also present results for face verification with impostor rejection. The MINACE parameter c trades-off distortion-tolerance (recognition) versus discrimination (impostor rejection) performance. We use an automated filter-synthesis algorithm to select c and to synthesize the MINACE filter for each person using a training set of images of that person and a validation set of a few faces of other persons; this synthesis ensures both good recognition and impostor rejection performance. No impostor data is present in the training or validation sets. The peak-tocorrelation energy ratio (PCE) metric is used as the match-score in both the filter-synthesis and test stages and we show that it is better than use of the correlation peak value. We use circular correlations in filter synthesis and in tests, since such filters require one-fourth the storage space and similarly fewer on-line correlation calculations compared to the use of linear correlation filters. All training set images are registered (aligned) using the coordinates of several facial landmarks to remove scale variations and tilt bias. We also discuss the proper handling of pose variations by either pose estimation or by transforming the test input to all reference poses. Our face recognition system is evaluated using images from the CMU Pose, Illumination, and Expression (PIE) database. The same set of MINACE filters and impostor faces are used to evaluate the performance of the face identification and verification systems.

  1. ROC analysis of ATR from SAR images using a model-based recognizer incorporating pose information

    NASA Astrophysics Data System (ADS)

    Cyganski, David; King, Brian M.; Vaz, Richard F.; Orr, John A.

    1995-06-01

    An automatic taget recognition (ATR) technique developed by the authors features analytically derived object models which are formed from entire image suites, yet are compact and allow a direct target recognition and pose determination procedure. In contrast to the pose-invariant information used to form the models in conventional approaches, view-dependent information is retained in the formation of the compact models for this new approach. All model-based ATR systems are confronted with the problem of image variation as a function of viewing angle. This problem can be addressed by use of an exhaustive library of views, at the expense of a large suite of literal images and a computationally intensive search-based recognition process. Means for overcoming these storage and processing obstacles have traditionally invloved some type of view-independent target representation, often developed from some composite view of the target over the viewing angles of interest. This results in a much more compact target model, and a more direct recognition process. Unfortunately, the gains in storage and computational requirements of these invariant algorithms come at the price of diminished target discrimination capability. The new algorithm incorporates pose as a fundamental parameter which is solved for as part of the recognition process, and does not discard the pose-related information which is relevant to target recognition. In this paper, the newly developed technique is applied to synthetic aperture radar images to develop receiver operating characteristic curves in the presence of both multiplicative noise and clutter. Comparative curves are also developed for a conventional generalized quandratic classifier ATR system.

  2. Challenges posed by extracellular vesicles from eukaryotic microbes

    PubMed Central

    Wolf, Julie M.; Casadevall, Arturo

    2014-01-01

    Extracellular vesicles (EV) produced by eukaryotic microbes play an important role during infection. EV release is thought to benefit microbial invasion by delivering a high concentration of virulence factors to distal host cells or to the cytoplasm of a host cell. EV can significantly impact the outcome of host-pathogen interaction in a cargo-dependent manner. Release of EV from eukaryotic microbes poses unique challenges when compared to their bacterial or archaeal counterparts. Firstly, the membrane-bound organelles within eukaryotes facilitate multiple mechanisms of vesicle generation. Secondly, the fungal cell wall poses a unique barrier between the vesicle release site at the plasma membrane and its destined extracellular environment. This review focuses on these eukaryotic-specific aspects of vesicle synthesis and release. PMID:25460799

  3. Wheel pose measurement based on cross structure light

    NASA Astrophysics Data System (ADS)

    Zhao, Qiancheng; Ding, Xun; Wang, Xian; Zhao, Yafeng

    2016-01-01

    It's necessary for automobile to detect and adjust four-wheel alignment parameters regularly, due to the significant effect on improving stability, enhancing security and reducing tire wear of automobiles. In order to measure the parameters that determined by relative position and posture of four wheels to the automobile cab, this paper proposes a method which applies monocular vision of linear structure light to wheel pose measurement. Firstly, space coordinates of feature point cloud are calculated out from the principle of structured light. Then, an algorithm is designed to determine the normal vector of wheel tangent plane and measure the wheel pose. Finally, actual experiments that by evaluation of adjusted wheel angle measurement are carried out to verify the system accuracy. The corresponding studies can be applied in designing and developing 3D four-wheel alignment system that based on structured light.

  4. Crew pose for portrait while training at KSC

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The STS 51-L crew poses for a portrait while training at Kennedy Space Center's (KSC) Launch complex 39, Pad B. They are standing in the White Room during a break in countdown training. Left to right are Teacher in Space Payload Specialist Sharon Christa McAuliffe; Payload Specialist Gregory Jarvis; and Astronauts Judith A. Resnik, mission specialist; Francis R. (Dick) Scobee, mission commander; Ronald E. McNair, mission specialist; Mike J. Smith, pilot; and Ellison S. Onizuka, mission specialist.

  5. 21. Dr. Harrison E. Stroud poses in front of his ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Dr. Harrison E. Stroud poses in front of his newly completed building at the northeast corner of Central Avenue and the alley north of Washington Street in about 1900 or 1901. In 1901, the building seen here was enlarged by the construction of an addition of similar design immediately to the north (left). Virtually the entire west elevation of the initial building is depicted in this view. Credit ADLAPR. - Stroud Building, 31-33 North Central Avenue, Phoenix, Maricopa County, AZ

  6. Temporally Scalable Visual SLAM using a Reduced Pose Graph

    DTIC Science & Technology

    2012-05-25

    generated from Kinect data for illustration purposes. II. RELATED WORK The pose graph optimization approach to SLAM was first introduced by Lu and Milios [19...such as the Microsoft Kinect ) and results for both camera types are presented in Section V. Additionally, our approach can incorporate IMU (roll and...camera, a Kinect sensor and a Microstrain IMU among other sensors. The data was collected in a large building over a period of six months. There were

  7. Intrinsic Feature Pose Measurement for Awake Animal SPECT Imaging

    SciTech Connect

    Goddard Jr, James Samuel; Baba, Justin S; Lee, Seung Joon; Weisenberger, A G; Stolin, A; McKisson, J; Smith, M F

    2009-01-01

    New developments have been made in optical motion tracking for awake animal imaging that measures 3D position and orientation (pose) for a single photon emission computed tomography (SPECT) imaging system. Ongoing SPECT imaging research has been directed towards head motion measurement for brain studies in awake, unrestrained mice. In contrast to previous results using external markers, this work extracts and tracks intrinsic features from multiple camera images and computes relative pose from the tracked features over time. Motion tracking thus far has been limited to measuring extrinsic features such as retro-reflective markers applied to the mouse s head. While this approach has been proven to be accurate, the additional animal handling required to attach the markers is undesirable. A significant improvement in the procedure is achieved by measuring the pose of the head without extrinsic markers using only the external surface appearance. This approach is currently being developed with initial results presented here. The intrinsic features measurement extracts discrete, sparse natural features from 2D images such as eyes, nose, mouth and other visible structures. Stereo correspondence between features for a camera pair is determined for calculation of 3D positions. These features are also tracked over time to provide continuity for surface model fitting. Experimental results from live images are presented.

  8. Teaching Human Poses Interactively to a Social Robot

    PubMed Central

    Gonzalez-Pacheco, Victor; Malfaz, Maria; Fernandez, Fernando; Salichs, Miguel A.

    2013-01-01

    The main activity of social robots is to interact with people. In order to do that, the robot must be able to understand what the user is saying or doing. Typically, this capability consists of pre-programmed behaviors or is acquired through controlled learning processes, which are executed before the social interaction begins. This paper presents a software architecture that enables a robot to learn poses in a similar way as people do. That is, hearing its teacher's explanations and acquiring new knowledge in real time. The architecture leans on two main components: an RGB-D (Red-, Green-, Blue- Depth) -based visual system, which gathers the user examples, and an Automatic Speech Recognition (ASR) system, which processes the speech describing those examples. The robot is able to naturally learn the poses the teacher is showing to it by maintaining a natural interaction with the teacher. We evaluate our system with 24 users who teach the robot a predetermined set of poses. The experimental results show that, with a few training examples, the system reaches high accuracy and robustness. This method shows how to combine data from the visual and auditory systems for the acquisition of new knowledge in a natural manner. Such a natural way of training enables robots to learn from users, even if they are not experts in robotics. PMID:24048336

  9. Teaching human poses interactively to a social robot.

    PubMed

    Gonzalez-Pacheco, Victor; Malfaz, Maria; Fernandez, Fernando; Salichs, Miguel A

    2013-09-17

    The main activity of social robots is to interact with people. In order to do that, the robot must be able to understand what the user is saying or doing. Typically, this capability consists of pre-programmed behaviors or is acquired through controlled learning processes, which are executed before the social interaction begins. This paper presents a software architecture that enables a robot to learn poses in a similar way as people do. That is, hearing its teacher's explanations and acquiring new knowledge in real time. The architecture leans on two main components: an RGB-D (Red-, Green-, Blue- Depth) -based visual system, which gathers the user examples, and an Automatic Speech Recognition (ASR) system, which processes the speech describing those examples. The robot is able to naturally learn the poses the teacher is showing to it by maintaining a natural interaction with the teacher. We evaluate our system with 24 users who teach the robot a predetermined set of poses. The experimental results show that, with a few training examples, the system reaches high accuracy and robustness. This method shows how to combine data from the visual and auditory systems for the acquisition of new knowledge in a natural manner. Such a natural way of training enables robots to learn from users, even if they are not experts in robotics.

  10. Shape recognition and pose estimation for mobile Augmented Reality.

    PubMed

    Hagbi, Nate; Bergig, Oriel; El-Sana, Jihad; Billinghurst, Mark

    2011-10-01

    Nestor is a real-time recognition and camera pose estimation system for planar shapes. The system allows shapes that carry contextual meanings for humans to be used as Augmented Reality (AR) tracking targets. The user can teach the system new shapes in real time. New shapes can be shown to the system frontally, or they can be automatically rectified according to previously learned shapes. Shapes can be automatically assigned virtual content by classification according to a shape class library. Nestor performs shape recognition by analyzing contour structures and generating projective-invariant signatures from their concavities. The concavities are further used to extract features for pose estimation and tracking. Pose refinement is carried out by minimizing the reprojection error between sample points on each image contour and its library counterpart. Sample points are matched by evolving an active contour in real time. Our experiments show that the system provides stable and accurate registration, and runs at interactive frame rates on a Nokia N95 mobile phone.

  11. Visual measurement system for roadheaders pose detection in mines

    NASA Astrophysics Data System (ADS)

    Du, Yuxin; Tong, Minming; Liu, Ting; Dong, Haibo

    2016-10-01

    To satisfy the demand for automatic roadway drivage in mines, a real-time body pose detection system is proposed for the mine-used boom-type roadheader. Utilizing cross lasers and laser targets as information sources, this system first establishes a mathematical model to describe the machine position in space and realizes the precise localization of reference points on targets via the improved Retinex adaptive image enhancement algorithm and maximum wavelet transform module algorithm. It then sets up the machine body position calculating model and makes use of the space matrix transformation method to obtain the yaw, pitch, roll angles, and horizontal and vertical deviations of the roadheader, finally fulfilling the automatic machine pose detection in real time. Based on the preceding theoretical analysis, an experimental platform is built up in laboratory conditions for the purpose of simulating pose changes of the machine inside the tunnel and automatically detecting its position. The experimental results show that the measurement accuracy of angles is within 0.16 deg and the detection precision of displacements is higher than 10 mm, which can satisfy requirements of automatic, precise, and real-time positioning for the roadheader during the process of tunnel construction.

  12. Pose-variant facial expression recognition using an embedded image system

    NASA Astrophysics Data System (ADS)

    Song, Kai-Tai; Han, Meng-Ju; Chang, Shuo-Hung

    2008-12-01

    In recent years, one of the most attractive research areas in human-robot interaction is automated facial expression recognition. Through recognizing the facial expression, a pet robot can interact with human in a more natural manner. In this study, we focus on the facial pose-variant problem. A novel method is proposed in this paper to recognize pose-variant facial expressions. After locating the face position in an image frame, the active appearance model (AAM) is applied to track facial features. Fourteen feature points are extracted to represent the variation of facial expressions. The distance between feature points are defined as the feature values. These feature values are sent to a support vector machine (SVM) for facial expression determination. The pose-variant facial expression is classified into happiness, neutral, sadness, surprise or anger. Furthermore, in order to evaluate the performance for practical applications, this study also built a low resolution database (160x120 pixels) using a CMOS image sensor. Experimental results show that the recognition rate is 84% with the self-built database.

  13. A WELL-POSED KELVIN-HELMHOLTZ INSTABILITY TEST AND COMPARISON

    SciTech Connect

    McNally, Colin P.; Lyra, Wladimir; Passy, Jean-Claude E-mail: wlyra@jpl.nasa.gov

    2012-08-01

    Recently, there has been a significant level of discussion of the correct treatment of Kelvin-Helmholtz instability (KHI) in the astrophysical community. This discussion relies largely on how the KHI test is posed and analyzed. We pose a stringent test of the initial growth of the instability. The goal is to provide a rigorous methodology for verifying a code on two-dimensional KHI. We ran the problem in the Pencil Code, Athena, Enzo, NDSPMHD, and Phurbas. A strict comparison, judgment, or ranking, between codes is beyond the scope of this work, though this work provides the mathematical framework needed for such a study. Nonetheless, how the test is posed circumvents the issues raised by tests starting from a sharp contact discontinuity yet it still shows the poor performance of smoothed particle hydrodynamics (SPH). We then comment on the connection between this behavior to the underlying lack of zeroth-order consistency in SPH interpolation. We comment on the tendency of some methods, particularly those with very low numerical diffusion, to produce secondary Kelvin-Helmholtz billows on similar tests. Though the lack of a fixed, physical diffusive scale in the Euler equations lies at the root of the issue, we suggest that in some methods an extra diffusion operator should be used to damp the growth of instabilities arising from grid noise. This statement applies particularly to moving-mesh tessellation codes, but also to fixed-grid Godunov schemes.

  14. STS-31 MS Sullivan poses next to stowed EMU in OV-103's airlock

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-31 Mission Specialist (MS) Kathryn D. Sullivan poses for a picture before beginning extravehicular mobility unit (EMU) donning procedures in the airlock of Discovery, Orbiter Vehicle (OV) 103. Sullivan will remove the lower torso restraint and don EMU which is supported on an airlock adapter plate (AAP). When suited, Sullivan will be ready for contingency extravehicular activity (EVA) in the event that problems arise with the Hubble Space Telescope (HST) deployment. Displayed on the front of the EMU are the STS-31 mission insignia and the JSC Weightless Environment Training Facility (WETF) insignia.

  15. Monocular Vision- and IMU-Based System for Prosthesis Pose Estimation During Total Hip Replacement Surgery.

    PubMed

    Su, Shaojie; Zhou, Yixin; Wang, Zhihua; Chen, Hong

    2017-03-30

    The average age of population increases worldwide, so does the number of total hip replacement surgeries. Total hip replacement, however, often involves a risk of dislocation and prosthetic impingement. To minimize the risk after surgery, we propose an instrumented hip prosthesis that estimates the relative pose between prostheses intraoperatively and ensures the placement of prostheses within a safe zone. We create a model of the hip prosthesis as a ball and socket joint, which has four degrees of freedom (DOFs), including 3-DOF rotation and 1-DOF translation. We mount a camera and an inertial measurement unit (IMU) inside the hollow ball, or "femoral head prosthesis," while printing customized patterns on the internal surface of the socket, or "acetabular cup." Since the sensors were rigidly fixed to the femoral head prosthesis, measuring its motions poses a sensor ego-motion estimation problem. By matching feature points in images of the reference patterns, we propose a monocular vision based method with a relative error of less than 7% in the 3-DOF rotation and 8% in the 1-DOF translation. Further, to reduce system power consumption, we apply the IMU with its data fused by an extended Kalman filter to replace the camera in the 3-DOF rotation estimation, which yields a less than 4.8% relative error and a 21.6% decrease in power consumption. Experimental results show that the best approach to prosthesis pose estimation is a combination of monocular vision-based translation estimation and IMU-based rotation estimation, and we have verified the feasibility and validity of this system in prosthesis pose estimation.

  16. Real-time upper-body human pose estimation from depth data using Kalman filter for simulator

    NASA Astrophysics Data System (ADS)

    Lee, D.; Chi, S.; Park, C.; Yoon, H.; Kim, J.; Park, C. H.

    2014-08-01

    Recently, many studies show that an indoor horse riding exercise has a positive effect on promoting health and diet. However, if a rider has an incorrect posture, it will be the cause of back pain. In spite of this problem, there is only few research on analyzing rider's posture. Therefore, the purpose of this study is to estimate a rider pose from a depth image using the Asus's Xtion sensor in real time. In the experiments, we show the performance of our pose estimation algorithm in order to comparing the results between our joint estimation algorithm and ground truth data.

  17. An Analog Model of Computation for the Ill-Posed Problems of Early Vision,

    DTIC Science & Technology

    1984-05-01

    minimizes the total power dissipated as heat5 . These results can be extended to nonlinear circuit components" (MacFarlane, 1970; Oster & Desoer , 1971...negative. Such a * negative resistance can be mimicked by operational amplifiers. 3 ’W%V An Example: Circuits for the Velocity Field Computation We will...measurements. They are equivalent, under steady-state conditions, to the electric circuit of figure lb. Fig. 2a illustrates a diffusion-reaction system. A

  18. Posing Problems Without an Alliance: China-Iran Relations after the Nuclear Deal

    DTIC Science & Technology

    2016-03-25

    enrichment and make other changes to its nuclear program in exchange for the removal of internation- al sanctions.1 China is expected to be a prime...will likely make only limited progress in developing more comprehensive strategic relations. Yet even a modest expansion of Sino-Iranian ties could...lacks sufficient refinery capacity of its own. Iran has also been a market for Chinese manufactured goods, such as consumer electronics, toys, and

  19. Youthfulness, inexperience, and sleep loss: the problems young drivers face and those they pose for us

    PubMed Central

    Groeger, J A

    2006-01-01

    Young inexperienced drivers are more likely to be involved in road traffic crashes than drivers who are older and more experienced. This paper argues that neither age nor inexperience are, in and of themselves, sufficient explanations of the association between age, experience, and casualty rates. The aim here is to consider what it is about inexperienced young drivers in particular that may increase crash risk. Evidence is reviewed showing differential sleep loss among different teenage groups, which may relate to recently presented evidence that young teenagers are more crash involved than drivers in their early twenties. Potential acute and chronic effects of sleep loss among teenagers and young adults are described. PMID:16788107

  20. The Problem with Women? Challenges Posed by Gender for Career Guidance Practice

    ERIC Educational Resources Information Center

    Bimrose, Jenny; Watson, Mark; McMahon, Mary; Haasler, Simone; Tomassini, Massimo; Suzanne, Pamela A.

    2014-01-01

    Institutionalised discrimination continues to perpetuate deep rooted social divisions, with gender inequality persisting as a pervasive feature of labour markets across the world. Despite the depth and breadth of gender inequality, there is limited acknowledgement in career theory that the career support needs of women are distinctive. A…

  1. [Diagnostic problems posed by hypotrophic facio-scapulo-humeral syndromes (author's transl)].

    PubMed

    Grassi, E; Marbini, A; Marchini, C; Parma, M; Zampollo, A

    1976-01-01

    The Authors, on the ground of the literature and of their own observations, stress the diagnostic non specificity of hypotrophic facio-scapulo-humeral syndromes: these sindromes, contrary to the current opinion, aren't always of primitive myodistrophic nature but may also be "neurogenic", inflammatory, collagenopathis, etc. In this connection they present an illustrative case of facio-scapulo-humeral syndrome which had clinical features typically "myogenic" but turned out to be "neurogenic" after electromyographic and histochemical investigation.

  2. Overview of potential mutagenic problems posed by some pesticides and their trace impurities.

    PubMed Central

    Fishbein, L

    1978-01-01

    This review principally addresses a number of aspects of usage of pesticides as well as populations at potential risk and attempts to highlight categories of pesticides whose structures or those of their metabolites and/or trace impurities, degradation and transformation products suggest an a priori mutagenic and/or carcinogenic risk. The pesticides considered include: DDT, hexachlorobenzene (HCB), 2,4,5-T, pentachlorophenol, and various herbicidal precursors (e.g., carbamates, triazines) of nitrosamines and nitroso derivatives. Structural features of a number of halo-unsaturated pesticides (e.g., dichloropropenes) were also reviewed from a viewpoint of contrasting their potential mutagenicity with that of vinyl chloride and vinylidene chloride. Additionally the mutagenicity of the organophosphorus pesticide Trichlorophon is contrasted with that of its degradation products. PMID:367764

  3. Field Dependence/Independence Cognitive Style and Problem Posing: An Investigation with Sixth Grade Students

    ERIC Educational Resources Information Center

    Nicolaou, Aristoklis Andreas; Xistouri, Xenia

    2011-01-01

    Field dependence/independence cognitive style was found to relate to general academic achievement and specific areas of mathematics; in the majority of studies, field-independent students were found to be superior to field-dependent students. The present study investigated the relationship between field dependence/independence cognitive style and…

  4. The Posing of Division Problems by Preservice Elementary School Teachers: Conceptual Knowledge and Contextual Connections.

    ERIC Educational Resources Information Center

    Silver, Edward A.; Burkett, Mary Lee

    Previous research has suggested that many elementary school teachers have a firmer understanding of addition and subtraction concepts than they have of more complex topics in elementary mathematics, such as division. In this study, (n=24) prospective elementary teachers' understanding of aspects of division involving remainders was explored by…

  5. Challenging the Wikipedia Mentality: Encouraging Original Inquiry through Freire's Problem-Posing Method

    ERIC Educational Resources Information Center

    Deys, Kellie L.; Deys, James L.

    2016-01-01

    For most millennials, information has always been a couple of quick taps away. Sites have seemingly always existed to provide them with "the answer." Instructors must recognize that not only are they teaching material from their disciplines, but also they are trying to teach the skill and value of critical inquiry. Adopting a Freirean…

  6. How cyanobacteria pose new problems to old methods: challenges in microarray time series analysis

    PubMed Central

    2013-01-01

    Background The transcriptomes of several cyanobacterial strains have been shown to exhibit diurnal oscillation patterns, reflecting the diurnal phototrophic lifestyle of the organisms. The analysis of such genome-wide transcriptional oscillations is often facilitated by the use of clustering algorithms in conjunction with a number of pre-processing steps. Biological interpretation is usually focussed on the time and phase of expression of the resulting groups of genes. However, the use of microarray technology in such studies requires the normalization of pre-processing data, with unclear impact on the qualitative and quantitative features of the derived information on the number of oscillating transcripts and their respective phases. Results A microarray based evaluation of diurnal expression in the cyanobacterium Synechocystis sp. PCC 6803 is presented. As expected, the temporal expression patterns reveal strong oscillations in transcript abundance. We compare the Fourier transformation-based expression phase before and after the application of quantile normalization, median polishing, cyclical LOESS, and least oscillating set (LOS) normalization. Whereas LOS normalization mostly preserves the phases of the raw data, the remaining methods introduce systematic biases. In particular, quantile-normalization is found to introduce a phase-shift of 180°, effectively changing night-expressed genes into day-expressed ones. Comparison of a large number of clustering results of differently normalized data shows that the normalization method determines the result. Subsequent steps, such as the choice of data transformation, similarity measure, and clustering algorithm, only play minor roles. We find that the standardization and the DTF transformation are favorable for the clustering of time series in contrast to the 12 m transformation. We use the cluster-wise functional enrichment of a clustering derived by LOS normalization, clustering using flowClust, and DFT transformation to derive the diurnal biological program of Synechocystis sp.. Conclusion Application of quantile normalization, median polishing, and also cyclic LOESS normalization of the presented cyanobacterial dataset lead to increased numbers of oscillating genes and the systematic shift of the expression phase. The LOS normalization minimizes the observed detrimental effects. As previous analyses employed a variety of different normalization methods, a direct comparison of results must be treated with caution. PMID:23601192

  7. Macrobend optical sensing for pose measurement in soft robot arms

    NASA Astrophysics Data System (ADS)

    Sareh, Sina; Noh, Yohan; Li, Min; Ranzani, Tommaso; Liu, Hongbin; Althoefer, Kaspar

    2015-12-01

    This paper introduces a pose-sensing system for soft robot arms integrating a set of macrobend stretch sensors. The macrobend sensory design in this study consists of optical fibres and is based on the notion that bending an optical fibre modulates the intensity of the light transmitted through the fibre. This sensing method is capable of measuring bending, elongation and compression in soft continuum robots and is also applicable to wearable sensing technologies, e.g. pose sensing in the wrist joint of a human hand. In our arrangement, applied to a cylindrical soft robot arm, the optical fibres for macrobend sensing originate from the base, extend to the tip of the arm, and then loop back to the base. The connectors that link the fibres to the necessary opto-electronics are all placed at the base of the arm, resulting in a simplified overall design. The ability of this custom macrobend stretch sensor to flexibly adapt its configuration allows preserving the inherent softness and compliance of the robot which it is installed on. The macrobend sensing system is immune to electrical noise and magnetic fields, is safe (because no electricity is needed at the sensing site), and is suitable for modular implementation in multi-link soft continuum robotic arms. The measurable light outputs of the proposed stretch sensor vary due to bend-induced light attenuation (macrobend loss), which is a function of the fibre bend radius as well as the number of repeated turns. The experimental study conducted as part of this research revealed that the chosen bend radius has a far greater impact on the measured light intensity values than the number of turns (if greater than five). Taking into account that the bend radius is the only significantly influencing design parameter, the macrobend stretch sensors were developed to create a practical solution to the pose sensing in soft continuum robot arms. Henceforward, the proposed sensing design was benchmarked against an electromagnetic

  8. A non-expert-user interface for posing signing avatars.

    PubMed

    Adamo-Villani, Nicoletta; Popescu, Voicu; Lestina, Jason

    2013-05-01

    We describe a graphical user interface designed to allow non-expert users to pose 3D characters to create American Sign Language (ASL) computer animation. The interface is an important component of a software system that allows educators of the Deaf to add sign language translation, in the form of 3D character animations, to digital learning materials, thus making them accessible to deaf learners. A study indicates that users with no computer animation expertize can create animated ASL signs quickly and accurately.

  9. Dynamics of solitons to the ill-posed Boussinesq equation

    NASA Astrophysics Data System (ADS)

    Tchier, Fairouz; Aliyu, Aliyu Isa; Yusuf, Abdullahi; Inc, Mustafa

    2017-03-01

    In this paper, we analyze the dynamic behavior of the ill-posed Boussinesq equation (IPBE) that arises in nonlinear lattices and also in shallow water waves. Some solitary wave solutions are obtained by using the solitary wave ansatz method and the Bernoulli sub-Ode. By applying the technique of nonlinear self-adjoint, a quasi self-adjoint substitution for the IPBE is constructed. The classical symmetries of the equation are constructed. Then, we used along with the obtained nonlinear self-adjoint substitution to construct a set of new conservation laws (Cls).

  10. Exterior view of submarine with survey crew posed in front. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Exterior view of submarine with survey crew posed in front. From left to right: Todd Croteau - U.S. National Park Service, Joshua Price - U.S. Navy, Bert Ho - National Oceanic and Atmospheric Administration, Michael McCarthy - Western Australia Maritime Museum, Larry Murphy - U.S. National Park Service, Don Johnson- University of Nebraska Engineering School, James Delgado- Institute for Nautical Archeology, Jacinto Ahmendra - Government of Panama. - Sub Marine Explorer, Located along the beach of Isla San Telmo, Pearl Islands, Isla San Telmo, Former Panama Canal Zone, CZ

  11. Exhaustive linearization for robust camera pose and focal length estimation.

    PubMed

    Penate-Sanchez, Adrian; Andrade-Cetto, Juan; Moreno-Noguer, Francesc

    2013-10-01

    We propose a novel approach for the estimation of the pose and focal length of a camera from a set of 3D-to-2D point correspondences. Our method compares favorably to competing approaches in that it is both more accurate than existing closed form solutions, as well as faster and also more accurate than iterative ones. Our approach is inspired on the EPnP algorithm, a recent O(n) solution for the calibrated case. Yet we show that considering the focal length as an additional unknown renders the linearization and relinearization techniques of the original approach no longer valid, especially with large amounts of noise. We present new methodologies to circumvent this limitation termed exhaustive linearization and exhaustive relinearization which perform a systematic exploration of the solution space in closed form. The method is evaluated on both real and synthetic data, and our results show that besides producing precise focal length estimation, the retrieved camera pose is almost as accurate as the one computed using the EPnP, which assumes a calibrated camera.

  12. High Methionine Diet Poses Cardiac Threat: A Molecular Insight.

    PubMed

    Chaturvedi, Pankaj; Kamat, Pradip K; Kalani, Anuradha; Familtseva, Anastasia; Tyagi, Suresh C

    2016-07-01

    High methionine diet (HMD) for example red meat which includes lamb, beef, pork can pose cardiac threat and vascular dysfunction but the mechanisms are unclear. We hypothesize that a diet rich in methionine can malfunction the cardiovascular system in three ways: (1) by augmenting oxidative stress; (2) by inflammatory manifestations; and (3) by matrix/vascular remodeling. To test this hypothesis we used four groups of mice: (1) WT; (2) WT + methionine; (3) CBS(+/-) ; (4) CBS(+/-) +methionine. We observed high oxidative stress in mice fed with methionine which was even higher in CBS(+/-) and CBS(+/-) +methionine. Higher oxidative stress was indicated by high levels of SOD-1 in methionine fed mouse hearts whereas IL-1β, IL-6, TNFα, and TLR4 showed high inflammatory manifestations. The upregulated levels of eNOS/iNOS and upregulated levels of MMP2/MMP9 along with high collagen deposition indicated vascular and matrix remodeling in methionine fed mouse. We evaluated the cardiac function which was dysregulated in the mice fed with HMD. These mice had decreased ejection fraction and left ventricular dysfunction which subsequently leads to adverse cardiac remodeling. In conclusion, our study clearly shows that HMD poses a cardiac threat by increasing oxidative stress, inflammatory manifestations, matrix/vascular remodeling, and decreased cardiac function.

  13. Pose Estimation and Mapping Using Catadioptric Cameras with Spherical Mirrors

    NASA Astrophysics Data System (ADS)

    Ilizirov, Grigory; Filin, Sagi

    2016-06-01

    Catadioptric cameras have the advantage of broadening the field of view and revealing otherwise occluded object parts. However, they differ geometrically from standard central perspective cameras because of light reflection from the mirror surface which alters the collinearity relation and introduces severe non-linear distortions of the imaged scene. Accommodating for these features, we present in this paper a novel modeling for pose estimation and reconstruction while imaging through spherical mirrors. We derive a closed-form equivalent to the collinearity principle via which we estimate the system's parameters. Our model yields a resection-like solution which can be developed into a linear one. We show that accurate estimates can be derived with only a small set of control points. Analysis shows that control configuration in the orientation scheme is rather flexible and that high levels of accuracy can be reached in both pose estimation and mapping. Clearly, the ability to model objects which fall outside of the immediate camera field-of-view offers an appealing means to supplement 3-D reconstruction and modeling.

  14. 3D face recognition under expressions, occlusions, and pose variations.

    PubMed

    Drira, Hassen; Ben Amor, Boulbaba; Srivastava, Anuj; Daoudi, Mohamed; Slama, Rim

    2013-09-01

    We propose a novel geometric framework for analyzing 3D faces, with the specific goals of comparing, matching, and averaging their shapes. Here we represent facial surfaces by radial curves emanating from the nose tips and use elastic shape analysis of these curves to develop a Riemannian framework for analyzing shapes of full facial surfaces. This representation, along with the elastic Riemannian metric, seems natural for measuring facial deformations and is robust to challenges such as large facial expressions (especially those with open mouths), large pose variations, missing parts, and partial occlusions due to glasses, hair, and so on. This framework is shown to be promising from both--empirical and theoretical--perspectives. In terms of the empirical evaluation, our results match or improve upon the state-of-the-art methods on three prominent databases: FRGCv2, GavabDB, and Bosphorus, each posing a different type of challenge. From a theoretical perspective, this framework allows for formal statistical inferences, such as the estimation of missing facial parts using PCA on tangent spaces and computing average shapes.

  15. Onboard camera pose estimation in augmented reality space for direct visual navigation

    NASA Astrophysics Data System (ADS)

    Hu, Zhencheng; Uchimura, Keiichi

    2003-05-01

    This paper presents a dynamical solution of the registration problem for on-road navigation applications via 3D-2D parameterized model matching algorithm. Traditional camera"s three dimensional (3D) position and pose estimation algorithms always employ the fixed and known-structure models as well as the depth information to obtain the 3D-2D correlations, which is however unavailable for on-road navigation applications since there are no fixed models in the general road scene. With the constraints of road structure and on-road navigation features, this paper presents a 2D digital road map based road shape modeling algorithm. Dynamically generated multi-lane road shape models are used to match real road scene to estimate camera 3D position and pose data. Our algorithms successfully simplified the 3D-2D correlation problem to the 2D-2D road model matching on the projective image. The algorithms proposed in this paper are validated with the experimental results from real road test under different conditions and types of road.

  16. [Ethical and health issues posed by the recent Ebola epidemic: What should we learn?].

    PubMed

    Pablo Beca, Juan; Salas, Sofía P

    2016-03-01

    The recent Ebola epidemic that affected several countries in Africa, with very high mortality and a pandemic threat, posed problems of justice, public health, prevention, treatment and research, each of which has relevant ethical issues. Despite severe initial difficulties, an effective international response was achieved, whose outcome has left significant teachings to be considered in order to deal with future epidemics or pandemics. In this article, the authors analyze the main problems faced during the Ebola epidemic, including the unequal distribution of health resources between countries, the need for international collaboration, the requirement for a review of the ethical standards of clinical trials in emergencies, and the necessity of an organized global system of prevention and timely response to these outbreaks. Authors conclude that at the present time health is a global issue without borders, that insufficient healthcare resources in some countries poses risks and affects all countries and that the confrontation of the threats of epidemics requires a solution based in universal solidarity. At the same time, a moral duty to investigate should be acknowledged, seeking a balance between sense of urgency, scientific rigor and involvement of local communities.

  17. Appearance learning for 3D pose detection of a satellite at close-range

    NASA Astrophysics Data System (ADS)

    Oumer, Nassir W.; Kriegel, Simon; Ali, Haider; Reinartz, Peter

    2017-03-01

    In this paper we present a learning-based 3D detection of a highly challenging specular object exposed to a direct sunlight at very close-range. An object detection is one of the most important areas of image processing, and can also be used for initialization of local visual tracking methods. While the object detection in 3D space is generally a difficult problem, it poses more difficulties when the object is specular and exposed to the direct sunlight as in a space environment. Our solution to a such problem relies on an appearance learning of a real satellite mock-up based on a vector quantization and the vocabulary tree. Our method, implemented on a standard computer (CPU), exploits a full perspective projection model and provides near real-time 3D pose detection of a satellite for close-range approach and manipulation. The time consuming part of the training (feature description, building the vocabulary tree and indexing, depth buffering and back-projection) are performed offline, while a fast image retrieval and 3D-2D registration are performed on-line. In contrast, the state of the art image-based 3D pose detection methods are slower on CPU or assume a weak perspective camera projection model. In our case the dimension of the satellite is larger than the distance to the camera, hence the assumption of the weak perspective model does not hold. To evaluate the proposed method, the appearance of a full scale mock-up of the rear part of the TerraSAR-X satellite is trained under various illumination and camera views. The training images are captured with a camera mounted on six degrees of freedom robot, which enables to position the camera in a desired view, sampled over a sphere. The views that are not within the workspace of the robot are interpolated using image-based rendering. Moreover, we generate ground truth poses to verify the accuracy of the detection algorithm. The achieved results are robust and accurate even under noise due to specular reflection

  18. Far and proximity maneuvers of a constellation of service satellites and autonomous pose estimation of customer satellite using machine vision

    NASA Astrophysics Data System (ADS)

    Arantes, Gilberto, Jr.; Marconi Rocco, Evandro; da Fonseca, Ijar M.; Theil, Stephan

    2010-05-01

    Space robotics has a substantial interest in achieving on-orbit satellite servicing operations autonomously, e.g. rendezvous and docking/berthing (RVD) with customer and malfunctioning satellites. An on-orbit servicing vehicle requires the ability to estimate the position and attitude in situations whenever the targets are uncooperative. Such situation comes up when the target is damaged. In this context, this work presents a robust autonomous pose system applied to RVD missions. Our approach is based on computer vision, using a single camera and some previous knowledge of the target, i.e. the customer spacecraft. A rendezvous analysis mission tool for autonomous service satellite has been developed and presented, for far maneuvers, e.g. distance above 1 km from the target, and close maneuvers. The far operations consist of orbit transfer using the Lambert formulation. The close operations include the inspection phase (during which the pose estimation is computed) and the final approach phase. Our approach is based on the Lambert problem for far maneuvers and the Hill equations are used to simulate and analyze the approaching and final trajectory between target and chase during the last phase of the rendezvous operation. A method for optimally estimating the relative orientation and position between camera system and target is presented in detail. The target is modelled as an assembly of points. The pose of the target is represented by dual quaternion in order to develop a simple quadratic error function in such a way that the pose estimation task becomes a least square minimization problem. The problem of pose is solved and some methods of non-linear square optimization (Newton, Newton-Gauss, and Levenberg-Marquard) are compared and discussed in terms of accuracy and computational cost.

  19. STS-110 and Expedition Four Crews Pose for Onboard Portrait

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Posed inside the Destiny Laboratory aboard the International Space Station (ISS) are the STS-110 and Expedition Four crews for a traditional onboard portrait From the left, bottom row, are astronauts Ellen Ochoa, STS mission specialist, Michael J. Bloomfield, STS mission commander, and Yury I Onufrienko, Expedition Four mission commander. From the left, middle row, are astronauts Daniel W. Bursch, Expedition Four flight engineer, Rex J. Walheim, STS mission specialist, and Carl E. Walz, Expedition Four flight engineer. From the left, top row, are astronauts Stephen N. Frick, STS pilot; Jerry L. Ross, Lee M.E. Morin, and Steven L. Smith, all mission specialists. Launched aboard the Space Shuttle Orbiter Atlantis on April 8, 2002, the STS-110 mission crew prepared the ISS for future space walks by installing and outfitting the 43-foot-long Starboard side S0 truss and preparing the Mobile Transporter. The mission served as the 8th ISS assembly flight.

  20. STS-85 crew poses at LC 39A during TCDT

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The STS-85 flight crew poses at Launch Pad 39A during a break in Terminal Countdown Demonstration Test (TCDT) activities for that mission. They are (back row, from left): Pilot Kent V. Rominger; Payload Commander N. Jan Davis; Mission Specialist Stephen K. Robinson; Payload Specialist Bjarni V. Tryggvason; Mission Specialist Robert L. Curbeam, Jr.; and Commander Curtis L. Brown, Jr. The primary payload aboard the Space Shuttle orbiter Discovery is the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-2 (CRISTA-SPAS-2). Other payloads on the 11- day mission include the Manipulator Flight Demonstration (MFD), and Technology Applications and Science-1 (TAS-1) and International Extreme Ultraviolet Hitchhiker-2 (IEH-2) experiments.

  1. Assessment of Risks Posed to VAD Patients During Disasters.

    PubMed

    Davis, Katherine J; O'Shea, Genevieve; Beach, Michael

    2017-04-06

    Ventricular assist devices (VADs) are an Advanced Life Support for patients with heart failure. These patients are particularly vulnerable in the event of a disaster. A hazard vulnerability analysis (HVA) was conducted to determine areas of susceptibility for these patients. Lack of electrical power, limited access to medications and anticoagulation, dehydration, extreme temperature and weather environments, conditions which predispose to infection, and evacuation transport are all identified circumstances that place these patients at an increased risk for harm and death. Future preparations in disaster planning are needed to address and mitigate these risks. Davis KJ , O'Shea G , Beach M . Assessment of risks posed to VAD patients during disasters. Prehosp Disaster Med. 2017;32(4):1-5.

  2. Expedition Three crew poses for photo on Fixed Service structure

    NASA Technical Reports Server (NTRS)

    2001-01-01

    KENNEDY SPACE CENTER, Fla. -- The Expedition Three crew poses on the Fixed Service Structure at Launch Pad 39A. From left are cosmonaut Mikhail Tyurin, commander Frank Culbertson and cosmonaut Vladimir Nikolaevich Dezhurov. The STS-105 and Expedition Three crews are at Kennedy Space Center participating in a Terminal Countdown Demonstration Test, a dress rehearsal for launch. The activities include emergency egress training, a simulated launch countdown and familiarization with the payload. Mission STS-105 will be transporting the Expedition Three crew, several payloads and scientific experiments to the International Space Station aboard Space Shuttle Discovery. The Expedition Two crew members currently on the Station will return to Earth on Discovery. The mission is scheduled to launch no earlier than Aug. 9, 2001.

  3. STS-105 crew poses for photo on Fixed Service Structure

    NASA Technical Reports Server (NTRS)

    2001-01-01

    KENNEDY SPACE CENTER, Fla. -- The STS-105 crew poses on the Fixed Service Structure at Launch Pad 39A. From left are Mission Specialist Patrick Forrester, Commander Scott Horowitz, Pilot Rick Sturckow and Mission Specialist Dan Barry. The STS-105 and Expedition Three crews are at Kennedy Space Center participating in a Terminal Countdown Demonstration Test, a dress rehearsal for launch. The activities include emergency egress training, a simulated launch countdown and familiarization with the payload. Mission STS-105 will be transporting the Expedition Three crew, several payloads and scientific experiments to the International Space Station aboard Space Shuttle Discovery. The Expedition Two crew members currently on the Station will return to Earth on Discovery. The mission is scheduled to launch no earlier than Aug. 9, 2001.

  4. Key participants in codeveloped technology pose for group picture

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Following the presentation of the Universal Signal Conditioning Amplifier (USCA), a new piece of technology developed through a National Aeronautics and Space Administration (NASA) partnership with industry, to Kennedy Space Center (KSC) Director Roy Bridges, Jr., key participants in the partnership pose for a group portrait. They are (from left) Bill Larson, NASA; Dr. Pedro Medelius, INET; Roy Bridges, Jr., KSC Director; Ed Gladney and William Saputo, L-3 Communications; Pam Gillespi, representing Congressman Dave Weldon; and Frank Kinney, Technological Research and Development Authority. The USCA is a key component of the codeveloped Automated Data Acquisition System (ADAS) that measures temperature, pressure and vibration at KSC's launch pads. The breakthrough technology is expected to reduce sensor setup and configuration times from hours to seconds. KSC teamed up with Florida's Technological Research and Development Authority and manufacturer L-3 Communications to produce a system that would benefit the aerospace industry and other commercial markets.

  5. Astronaut David Brown poses with ComBBat team

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Astronaut David Brown poses with members of the team known as ComBBat, representing Central Florida's Astronaut and Titusville high schools. ComBBat was teamed with Boeing at KSC and Brevard Community College. Students from all over the country are at the KSC Visitor Complex for the FIRST (For Inspiration and Recognition of Science and Technology) Southeast Regional competition being held March 9-11 in the Rocket Garden. Teams of high school students are testing the limits of their imagination using robots they have designed, with the support of business and engineering professionals and corporate sponsors, to compete in a technological battle against other schools' robots. Of the 30 high school teams competing, 16 are Florida teams co-sponsored by NASA and KSC contractors. Local high schools participating are Astronaut, Bayside, Cocoa Beach, Eau Gallie, Melbourne, Melbourne Central Catholic, Palm Bay, Rockledge, Satellite, and Titusville.

  6. Intrinsic feature-based pose measurement for imaging motion compensation

    DOEpatents

    Baba, Justin S.; Goddard, Jr., James Samuel

    2014-08-19

    Systems and methods for generating motion corrected tomographic images are provided. A method includes obtaining first images of a region of interest (ROI) to be imaged and associated with a first time, where the first images are associated with different positions and orientations with respect to the ROI. The method also includes defining an active region in the each of the first images and selecting intrinsic features in each of the first images based on the active region. Second, identifying a portion of the intrinsic features temporally and spatially matching intrinsic features in corresponding ones of second images of the ROI associated with a second time prior to the first time and computing three-dimensional (3D) coordinates for the portion of the intrinsic features. Finally, the method includes computing a relative pose for the first images based on the 3D coordinates.

  7. Level of environmental threat posed by horticultural trade in Cactaceae.

    PubMed

    Novoa, Ana; Le Roux, Johannes J; Richardson, David M; Wilson, John R U

    2017-01-11

    Ornamental horticulture has been identified as an important threat to plant biodiversity and the major pathway for plant invasions worldwide. In this context, the family Cactaceae is particularly interesting and challenging for three main reasons-it is considered the fifth most threatened major taxonomic group in the world; several cactus species are amongst the most widespread and damaging invasive species; and Cactaceae is one of the most popular horticultural plant groups. Based on CITES trade data and the eleven main auction sites selling cacti on the internet we document a substantial global trade from and to almost all continents. While less than 20 % of this trade involves threatened species, and less than 3% involves known invasive species, many species are sold without a valid scientific name. Importantly, however, hardly any of the globally traded cacti are collected from wild populations. In order to provide an in-depth look at the dynamics of the industry, we surveyed the businesses involved in the cactus trade in South Africa (one of the main hotspots of cactus trade and invasions). Despite a large commercial network, all South African imports (of which only 15 % and 1.5 % were of species listed as threatened and invasive, respectively) came from the same source. We purchased seeds of every available species and, based on DNA-barcoding techniques, could only identify 24 % of the species to genus level. If trade restrictions are placed on the small proportion of cacti that are invasive and there is no major increase in harvesting of native populations, the commercial cactus horticultural trade will pose a negligible environmental threat. However, there are currently no effective methods for easily identifying which cacti are traded, and both the illicit harvesting of cacti from the wild and the informal trade in invasive taxa pose on-going conservation challenges. This article is protected by copyright. All rights reserved.

  8. On an ill-posed model of oscillations of a flat plate with a variety of mounts on opposite sides

    NASA Astrophysics Data System (ADS)

    Iskakova, Ulzada A.

    2016-08-01

    In this paper, we consider a model case of stationary vibrations of a thin flat plate, one side of which is embedded, the opposite side is free, and the sides are freely leaned. In mathematical modeling, there is a local boundary value problem for the biharmonic equation in a rectangular domain. Boundary conditions are given on all boundary of the domain. We show that the considered problem is self-adjoint. Herewith, the problem is ill-posed. We show that the stability of solution to the problem is disturbed. Necessary and sufficient conditions of existence of the problem solution are found. Spaces of the ill-posedness of the considered problem are constructed.

  9. Robustly Aligning a Shape Model and Its Application to Car Alignment of Unknown Pose.

    PubMed

    Li, Yan; Gu, Leon; Kanade, Takeo

    2011-09-01

    Precisely localizing in an image a set of feature points that form a shape of an object, such as car or face, is called alignment. Previous shape alignment methods attempted to fit a whole shape model to the observed data, based on the assumption of Gaussian observation noise and the associated regularization process. However, such an approach, though able to deal with Gaussian noise in feature detection, turns out not to be robust or precise because it is vulnerable to gross feature detection errors or outliers resulting from partial occlusions or spurious features from the background or neighboring objects. We address this problem by adopting a randomized hypothesis-and-test approach. First, a Bayesian inference algorithm is developed to generate a shape-and-pose hypothesis of the object from a partial shape or a subset of feature points. For alignment, a large number of hypotheses are generated by randomly sampling subsets of feature points, and then evaluated to find the one that minimizes the shape prediction error. This method of randomized subset-based matching can effectively handle outliers and recover the correct object shape. We apply this approach on a challenging data set of over 5,000 different-posed car images, spanning a wide variety of car types, lighting, background scenes, and partial occlusions. Experimental results demonstrate favorable improvements over previous methods on both accuracy and robustness.

  10. Assessing the risk posed by high-turbidity water to water supplies.

    PubMed

    Chang, Chia-Ling; Liao, Chung-Sheng

    2012-05-01

    The objective of this study is to assess the risk of insufficient water supply posed by high-turbidity water. Several phenomena can pose risks to the sufficiency of a water supply; this study concerns risks to water treatment plants from particular properties of rainfall and raw water turbidity. High-turbidity water can impede water treatment plant operations; rainfall properties can influence the degree of soil erosion. Thus, water turbidity relates to rainfall characteristics. Exceedance probabilities are presented for different rainfall intensities and turbidities of water. When the turbidity of raw water is higher than 5,000 NTU, it can cause operational problems for a water treatment plant. Calculations show that the turbidity of raw water at the Ban-Sin water treatment plant will be higher than 5,000 NTU if the rainfall intensity is larger than 165 mm/day. The exceedance probability of high turbidity (turbidity >5,000 NTU) in the Ban-Sin water treatment plant is larger than 10%. When any water treatment plant cannot work regularly, its ability to supply water to its customers is at risk.

  11. 3D sensor algorithms for spacecraft pose determination

    NASA Astrophysics Data System (ADS)

    Trenkle, John M.; Tchoryk, Peter, Jr.; Ritter, Greg A.; Pavlich, Jane C.; Hickerson, Aaron S.

    2006-05-01

    Researchers at the Michigan Aerospace Corporation have developed accurate and robust 3-D algorithms for pose determination (position and orientation) of satellites as part of an on-going effort supporting autonomous rendezvous, docking and space situational awareness activities. 3-D range data from a LAser Detection And Ranging (LADAR) sensor is the expected input; however, the approach is unique in that the algorithms are designed to be sensor independent. Parameterized inputs allow the algorithms to be readily adapted to any sensor of opportunity. The cornerstone of our approach is the ability to simulate realistic range data that may be tailored to the specifications of any sensor. We were able to modify an open-source raytracing package to produce point cloud information from which high-fidelity simulated range images are generated. The assumptions made in our experimentation are as follows: 1) we have access to a CAD model of the target including information about the surface scattering and reflection characteristics of the components; 2) the satellite of interest may appear at any 3-D attitude; 3) the target is not necessarily rigid, but does have a limited number of configurations; and, 4) the target is not obscured in any way and is the only object in the field of view of the sensor. Our pose estimation approach then involves rendering a large number of exemplars (100k to 5M), extracting 2-D (silhouette- and projection-based) and 3-D (surface-based) features, and then training ensembles of decision trees to predict: a) the 4-D regions on a unit hypersphere into which the unit quaternion that represents the vehicle [Q X, Q Y, Q Z, Q W] is pointing, and, b) the components of that unit quaternion. Results have been quite promising and the tools and simulation environment developed for this application may also be applied to non-cooperative spacecraft operations, Autonomous Hazard Detection and Avoidance (AHDA) for landing craft, terrain mapping, vehicle

  12. Invasive Lionfish (Pterosis volitans) Pose Public Health Threats.

    PubMed

    Diaz, James H

    2015-01-01

    The lionfish, Pterosis volitans, a native of Indo-Pacific oceans, is a popular saltwater aquarium fish despite venomous spines on its fins. Lionfish were inadvertently introduced into the western Atlantic from Florida in the early 1990s and have overpopulated and dispersed widely into the Caribbean Sea and Gulf of Mexico. Initiatives to control lionfish populations were launched, including the National Oceanographic and Atmospheric Administration (NOAA)-sponsored "Lionfish as Food Campaign".2 Recently, scientists from the Food and Drug Administration (FDA) reported that lionfish caught off the US Virgin Islands contained ciguatoxins and could cause ciguatera fish poisoning (CFP); a seafood-borne poisoning without an antidote or any specific treatment, and a potential for prolonged neurotoxicity. Lionfish pose several public health threats. New strategies to control the lionfish population explosion in coastal waters and offshore fisheries are needed now to ensure seafood safety and public health. The lionfish, Pterosis volitans, is native to the reefs of the western Indian and Pacific Oceans (Figure 1). Brightly colored with red, white, and black stripes and adorned with feathery fins, the lionfish is a popular saltwater aquarium fish despite venomous spines on its fins (Figure 2). Lionfish were introduced into the western North Atlantic from Florida in the early 1990s after some specimens were discarded by dissatisfied amateur aquarists and others escaped from hurricane-flooded public aquariums.1 Since lionfish are voracious carnivores, have few natural predators, and reproduce prolifically, they have overpopulated and dispersed widely from Cape Hatteras to Florida, throughout the Caribbean Sea, and into the Gulf of Mexico.1 The population density of lionfish in its new, invaded territory now exceeds that of its native habitat.1 As a result, campaigns to control lionfish populations were launched in Florida and the Caribbean. Lionfish now pose several public

  13. STS-95 Payload Specialist Mukai poses with NASDA president

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-95 Payload Specialist Chiaki Mukai, M.D. (center), with the National Space Development Agency of Japan (NASDA), poses for a photograph with NASDA President Isao Uchida (left). Behind her at the right is a representative of the European Space Agency (ESA). Mukai was one of a crew of seven aboard orbiter Discovery, which landed at KSC at 12:04 p.m. EST, after a successful mission spanning nine days and 3.6 million miles. The other crew members are Mission Commander Curtis L. Brown Jr.; Pilot Steven W. Lindsey; Mission Specialists Stephen K. Robinson; Scott E. Parazynski and Pedro Duque of Spain, with the European Space Agency; and Payload Specialist John H. Glenn Jr., senator from Ohio. The mission included research payloads such as the Spartan solar-observing deployable spacecraft, the Hubble Space Telescope Orbital Systems Test Platform, the International Extreme Ultraviolet Hitchhiker, as well as the SPACEHAB single module with experiments on space flight and the aging process.

  14. Does ketoprofen or diclofenac pose the lowest risk to fish?

    PubMed

    Cuklev, Filip; Fick, Jerker; Cvijovic, Marija; Kristiansson, Erik; Förlin, Lars; Larsson, D G Joakim

    2012-08-30

    Ketoprofen and diclofenac are non-steroidal anti-inflammatory drugs (NSAIDs) often used for similar indications, and both are frequently found in surface waters. Diclofenac affects organ histology and gene expression in fish at around 1 μg/L. Here, we exposed rainbow trout to ketoprofen (1, 10 and 100 μg/L) to investigate if this alternative causes less risk for pharmacological responses in fish. The bioconcentration factor from water to fish blood plasma was <0.05 (4 for diclofenac based on previous studies). Ketoprofen only reached up to 0.6 ‰ of the human therapeutic plasma concentration, thus the probability of target-related effects was estimated to be fairly low. Accordingly, a comprehensive analysis of hepatic gene expression revealed no consistent responses. In some contrast, trout exposed to undiluted, treated sewage effluents bioconcentrated ketoprofen and other NSAIDs much more efficiently, according to a meta-analysis of recent studies. Neither of the setups is however an ideal representation of the field situation. If a controlled exposure system with a single chemical in pure water is a reasonable representation of the environment, then the use of ketoprofen is likely to pose a lower risk for wild fish than diclofenac, but if bioconcentration factors from effluent-exposed fish are applied, the risks may be more similar.

  15. Reappraisal of biosafety risks posed by PERVs in xenotransplantation.

    PubMed

    Louz, Derrick; Bergmans, Hans E; Loos, Birgit P; Hoeben, Rob C

    2008-01-01

    Donor materials of porcine origin could potentially provide an alternative source of cells, tissues or whole organs for transplantation to humans, but is hampered by the health risk posed by infection with porcine viruses. Although pigs can be bred in such a way that all known exogenous microorganisms are eliminated, this is not feasible for all endogenous pathogens, such as the porcine endogenous retroviruses (PERVs) which are present in the germline of pigs as proviruses. Upon transplantation, PERV proviruses would be transferred to the human recipient along with the xenograft. If xenotransplantation stimulates or facilitates replication of PERVs in the new hosts, a risk exists for adaptation of the virus to humans and subsequent spread of these viruses. In a worst-case scenario, this might result in the emergence of a new viral disease. Although the concerns for disease potential of PERVs are easing, only limited pre-clinical and clinical data are available. Small-scale, well-designed and carefully controlled clinical trials would provide more evidence on the safety of this approach and allow a better appreciation of the risks involved. It is therefore important to have a framework of protective measures and monitoring protocols in place to facilitate such initially small scale clinical trials. This framework will raise ethical and social considerations regarding acceptability.

  16. Pose invariant face recognition: 3D model from single photo

    NASA Astrophysics Data System (ADS)

    Napoléon, Thibault; Alfalou, Ayman

    2017-02-01

    Face recognition is widely studied in the literature for its possibilities in surveillance and security. In this paper, we report a novel algorithm for the identification task. This technique is based on an optimized 3D modeling allowing to reconstruct faces in different poses from a limited number of references (i.e. one image by class/person). Particularly, we propose to use an active shape model to detect a set of keypoints on the face necessary to deform our synthetic model with our optimized finite element method. Indeed, in order to improve our deformation, we propose a regularization by distances on graph. To perform the identification we use the VanderLugt correlator well know to effectively address this task. On the other hand we add a difference of Gaussian filtering step to highlight the edges and a description step based on the local binary patterns. The experiments are performed on the PHPID database enhanced with our 3D reconstructed faces of each person with an azimuth and an elevation ranging from -30° to +30°. The obtained results prove the robustness of our new method with 88.76% of good identification when the classic 2D approach (based on the VLC) obtains just 44.97%.

  17. Real-time pose invariant logo and pattern detection

    NASA Astrophysics Data System (ADS)

    Sidla, Oliver; Kottmann, Michal; Benesova, Wanda

    2011-01-01

    The detection of pose invariant planar patterns has many practical applications in computer vision and surveillance systems. The recognition of company logos is used in market studies to examine the visibility and frequency of logos in advertisement. Danger signs on vehicles could be detected to trigger warning systems in tunnels, or brand detection on transport vehicles can be used to count company-specific traffic. We present the results of a study on planar pattern detection which is based on keypoint detection and matching of distortion invariant 2d feature descriptors. Specifically we look at the keypoint detectors of type: i) Lowe's DoG approximation from the SURF algorithm, ii) the Harris Corner Detector, iii) the FAST Corner Detector and iv) Lepetit's keypoint detector. Our study then compares the feature descriptors SURF and compact signatures based on Random Ferns: we use 3 sets of sample images to detect and match 3 logos of different structure to find out which combinations of keypoint detector/feature descriptors work well. A real-world test tries to detect vehicles with a distinctive logo in an outdoor environment under realistic lighting and weather conditions: a camera was mounted on a suitable location for observing the entrance to a parking area so that incoming vehicles could be monitored. In this 2 hour long recording we can successfully detect a specific company logo without false positives.

  18. Inverse problems in mathematical physics

    NASA Astrophysics Data System (ADS)

    Glasko, V. B.

    Procedures for the correct formulation and solution of inverse problems, which usually belong to the class of ill-posed problems, are discussed. Attention is given to the concept of the conditionally correct statement of a problem, the concept of quasi-solution, and the fundamentals of regularization theory. The discussion also covers the uniqueness of solutions to inverse problems in mathematical physics, with consideration given to problems involving layered media, impedance problems, gravimetric problems, and inverse problems of heat conduction. The problem of stability and regularizing operators are also discussed.

  19. Lossless divide and conquer for time-order sorting of N facial poses

    NASA Astrophysics Data System (ADS)

    Hsu, Ming Kai; Szu, Harold

    2011-06-01

    Law enforcement agencies need a quick decision in May 1 2010 NY Time Square for quickly spot wanted car bomb individuals in a crowd. This goal requires real-time smart firmware and a smart search algorithm to know how to order the faces in a geometric way. We demonstrate such a sorting problem of N facial poses time ordering is like the TSP of N cities, NP-complete, having no exact deterministic solution. Here we demonstrated a heuristic working solution to answer the ONR grand challenge called Empire 2010. How could the N boxes of faces detected and cut by the efficient COST parallel color-hue-algorithm, without time mark, at a single CPU (or even with the time marks but collected videos from multiple vintage points) to determine automatically who speaks what, where, and when? There must be a cross platform sensory association from our different sensors.

  20. Semi-automatic identification photo generation with facial pose and illumination normalization

    NASA Astrophysics Data System (ADS)

    Jiang, Bo; Liu, Sijiang; Wu, Song

    2016-07-01

    Identification photo is a category of facial image that has strict requirements on image quality like size, illumination, user expression, dressing, etc. Traditionally, these photos are taken in professional studios. With the rapid popularity of mobile devices, how to conveniently take identification photo at any time and anywhere with such devices is an interesting problem. In this paper, we propose a novel semi-automatic identification photo generation approach. Given a user image, facial pose and expression are first normalized to meet the basic requirements. To correct uneven lighting condition in photo, an facial illumination normalization approach is adopted to further improve the image quality. Finally, foreground user is extracted and re-targeted to a specific photo size. Besides, background can also be changed as required. Preliminary experimental results show that the proposed method is efficient and effective in identification photo generation compared to commercial software based manual tunning.

  1. Allocation Games: Addressing the Ill-Posed Nature of Allocation in Life-Cycle Inventories.

    PubMed

    Hanes, Rebecca J; Cruze, Nathan B; Goel, Prem K; Bakshi, Bhavik R

    2015-07-07

    Allocation is required when a life cycle contains multi-functional processes. One approach to allocation is to partition the embodied resources in proportion to a criterion, such as product mass or cost. Many practitioners apply multiple partitioning criteria to avoid choosing one arbitrarily. However, life cycle results from different allocation methods frequently contradict each other, making it difficult or impossible for the practitioner to draw any meaningful conclusions from the study. Using the matrix notation for life-cycle inventory data, we show that an inventory that requires allocation leads to an ill-posed problem: an inventory based on allocation is one of an infinite number of inventories that are highly dependent upon allocation methods. This insight is applied to comparative life-cycle assessment (LCA), in which products with the same function but different life cycles are compared. Recently, there have been several studies that applied multiple allocation methods and found that different products were preferred under different methods. We develop the Comprehensive Allocation Investigation Strategy (CAIS) to examine any given inventory under all possible allocation decisions, enabling us to detect comparisons that are not robust to allocation, even when the comparison appears robust under conventional partitioning methods. While CAIS does not solve the ill-posed problem, it provides a systematic way to parametrize and examine the effects of partitioning allocation. The practical usefulness of this approach is demonstrated with two case studies. The first compares ethanol produced from corn stover hydrolysis, corn stover gasification, and corn grain fermentation. This comparison was not robust to allocation. The second case study compares 1,3-propanediol (PDO) produced from fossil fuels and from biomass, which was found to be a robust comparison.

  2. Choosing parameters of kernel subspace LDA for recognition of face images under pose and illumination variations.

    PubMed

    Huang, Jian; Yuen, Pong C; Chen, Wen-Sheng; Lai, Jian Huang

    2007-08-01

    This paper addresses the problem of automatically tuning multiple kernel parameters for the kernel-based linear discriminant analysis (LDA) method. The kernel approach has been proposed to solve face recognition problems under complex distribution by mapping the input space to a high-dimensional feature space. Some recognition algorithms such as the kernel principal components analysis, kernel Fisher discriminant, generalized discriminant analysis, and kernel direct LDA have been developed in the last five years. The experimental results show that the kernel-based method is a good and feasible approach to tackle the pose and illumination variations. One of the crucial factors in the kernel approach is the selection of kernel parameters, which highly affects the generalization capability and stability of the kernel-based learning methods. In view of this, we propose an eigenvalue-stability-bounded margin maximization (ESBMM) algorithm to automatically tune the multiple parameters of the Gaussian radial basis function kernel for the kernel subspace LDA (KSLDA) method, which is developed based on our previously developed subspace LDA method. The ESBMM algorithm improves the generalization capability of the kernel-based LDA method by maximizing the margin maximization criterion while maintaining the eigenvalue stability of the kernel-based LDA method. An in-depth investigation on the generalization performance on pose and illumination dimensions is performed using the YaleB and CMU PIE databases. The FERET database is also used for benchmark evaluation. Compared with the existing PCA-based and LDA-based methods, our proposed KSLDA method, with the ESBMM kernel parameter estimation algorithm, gives superior performance.

  3. Making Faces: Age and Emotion Differences in the Posing of Emotional Expressions.

    ERIC Educational Resources Information Center

    Lewis, Michael; And Others

    1987-01-01

    Videotape study of preschool children, two to five years of age, and adults who posed the six facial expressions of happiness, surprise, anger, fear, sadness, and disgust. Poses were scored using the MAX system. Results showed that consistent differences between partial and complete poses were observed for negative expressions. (Author/RWB)

  4. The challenge posed by endocrine-disrupting chemicals.

    PubMed

    Ashby, J; Houthoff, E; Kennedy, S J; Stevens, J; Bars, R; Jekat, F W; Campbell, P; Van Miller, J; Carpanini, F M; Randall, G L

    1997-02-01

    Rapid regulatory developments in the area of environmental endocrine disruption present a series of potential problems that are identified and illustrated with examples taken from the recent literature. A list of priorities is provided, including the need for additional epidemiological and wildlife studies, the derivation of a coordinated testing strategy, agreement on the toxicities expected of endocrine disrupting agents, and acceptance that whole animal assays will be uniquely critical in this area of toxicology. The intrinsic difficulty of attempting to simultaneously study all aspects of endocrine disruption indicates the need to reduce the scope of the problem, which can be achieved by first studying toxicities mediated by sex hormone receptors.

  5. The challenge posed by endocrine-disrupting chemicals.

    PubMed Central

    Ashby, J; Houthoff, E; Kennedy, S J; Stevens, J; Bars, R; Jekat, F W; Campbell, P; Van Miller, J; Carpanini, F M; Randall, G L

    1997-01-01

    Rapid regulatory developments in the area of environmental endocrine disruption present a series of potential problems that are identified and illustrated with examples taken from the recent literature. A list of priorities is provided, including the need for additional epidemiological and wildlife studies, the derivation of a coordinated testing strategy, agreement on the toxicities expected of endocrine disrupting agents, and acceptance that whole animal assays will be uniquely critical in this area of toxicology. The intrinsic difficulty of attempting to simultaneously study all aspects of endocrine disruption indicates the need to reduce the scope of the problem, which can be achieved by first studying toxicities mediated by sex hormone receptors. PMID:9105789

  6. Assessing the risk posed by natural hazards to infrastructures

    NASA Astrophysics Data System (ADS)

    Eidsvig, Unni; Kristensen, Krister; Vidar Vangelsten, Bjørn

    2015-04-01

    The modern society is increasingly dependent on infrastructures to maintain its function, and disruption in one of the infrastructure systems may have severe consequences. The Norwegian municipalities have, according to legislation, a duty to carry out a risk and vulnerability analysis and plan and prepare for emergencies in a short- and long term perspective. Vulnerability analysis of the infrastructures and their interdependencies is an important part of this analysis. This paper proposes a model for assessing the risk posed by natural hazards to infrastructures. The model prescribes a three level analysis with increasing level of detail, moving from qualitative to quantitative analysis. This paper focuses on the second level, which consists of a semi-quantitative analysis. The purpose of this analysis is to perform a screening of the scenarios of natural hazards threatening the infrastructures identified in the level 1 analysis and investigate the need for further analyses, i.e. level 3 quantitative analyses. The proposed level 2 analysis considers the frequency of the natural hazard, different aspects of vulnerability including the physical vulnerability of the infrastructure itself and the societal dependency on the infrastructure. An indicator-based approach is applied, ranking the indicators on a relative scale. The proposed indicators characterize the robustness of the infrastructure, the importance of the infrastructure as well as interdependencies between society and infrastructure affecting the potential for cascading effects. Each indicator is ranked on a 1-5 scale based on pre-defined ranking criteria. The aggregated risk estimate is a combination of the semi-quantitative vulnerability indicators, as well as quantitative estimates of the frequency of the natural hazard and the number of users of the infrastructure. Case studies for two Norwegian municipalities are presented, where risk to primary road, water supply and power network threatened by storm

  7. STS-103 crew pose in front of Pad 39B

    NASA Technical Reports Server (NTRS)

    1999-01-01

    During Terminal Countdown Demonstration Test (TDCT) activities at Launch Pad 39B, the STS-103 crew pose in front of the flame trench, which is situated underneath the Mobile Launcher Platform holding Space Shuttle Discovery. Standing left to right are Mission Specialists Claude Nicollier of Switzerland, who is with the European Space Agency (ESA), C. Michael Foale (Ph.D.), John M. Grunsfeld (Ph.D.), Pilot Scott J. Kelly, Commander Curtis L. Brown Jr., and Mission Specialists Jean-Frangois Clervoy of France, also with ESA, and Steven L. Smith. One of the solid rocket boosters and the external tank that are attached to Discovery can be seen in the photo. The flame trench is made of concrete and refractory brick, and contains an orbiter flame deflector on one side and solid rocket booster flame deflector on the other. The deflectors protect the flame trench floor and pad surface from the intense heat of launch. The TCDT provides the crew with emergency egress training, opportunities to inspect their mission payloads in the orbiter's payload bay, and simulated countdown exercises. STS-103 is a 'call-up' mission due to the need to replace and repair portions of the Hubble Space Telescope, including the gyroscopes that allow the telescope to point at stars, galaxies and planets. The STS-103 crew will be replacing a Fine Guidance Sensor, an older computer with a new enhanced model, an older data tape recorder with a solid-state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Four EVA's are planned to make the necessary repairs and replacements on the telescope. The mission is targeted for launch Dec. 6 at 2:37 a.m. EST.

  8. Crisis planning to manage risks posed by animal rights extremists.

    PubMed

    Bailey, Matthew R; Rich, Barbara A; Bennett, B Taylor

    2010-01-01

    Among the multitude of crises that US research institutions may face are those caused by animal rights activists. While most activists opposed to animal research use peaceful and lawful means of expressing their opinions, some extremists resort to illegal methods. Arson, break-ins, and theft with significant property damage at US animal research facilities began in the 1980s. The most troubling trend to develop in the past decade is the targeting of individuals associated with animal research, whether directly or indirectly, and the use of violent scare tactics to intimidate researchers and their families. The National Association for Biomedical Research has a 30-year history of monitoring the animal rights movement and assisting member institutions with crisis situations. In this article we discuss attacks on researchers at their homes, cyber crimes, exploitation of new media formats, infiltration of research facilities, and the targeting of external research stakeholders and business partners. We describe the need for a well-conceived crisis management plan and strong leadership to mitigate crisis situations. Institutions with well-informed leaders and crisis management teams ready to take timely action are best equipped to protect staff, laboratory animals, and research programs. They act on early warnings, provide support for targeted staff, seek legal remedies, thoughtfully control access to research facilities, and identify and enlist new research supporters. We underscore the importance of up-to-date crisis planning so that institutions are not only aware of ongoing risks posed by animal rights extremists but also better prepared to take preemptive action and able to manage those risks successfully.

  9. An investigation into multi-dimensional prediction models to estimate the pose error of a quadcopter in a CSP plant setting

    NASA Astrophysics Data System (ADS)

    Lock, Jacobus C.; Smit, Willie J.; Treurnicht, Johann

    2016-05-01

    The Solar Thermal Energy Research Group (STERG) is investigating ways to make heliostats cheaper to reduce the total cost of a concentrating solar power (CSP) plant. One avenue of research is to use unmanned aerial vehicles (UAVs) to automate and assist with the heliostat calibration process. To do this, the pose estimation error of each UAV must be determined and integrated into a calibration procedure. A computer vision (CV) system is used to measure the pose of a quadcopter UAV. However, this CV system contains considerable measurement errors. Since this is a high-dimensional problem, a sophisticated prediction model must be used to estimate the measurement error of the CV system for any given pose measurement vector. This paper attempts to train and validate such a model with the aim of using it to determine the pose error of a quadcopter in a CSP plant setting.

  10. Accuracy and robustness of Kinect pose estimation in the context of coaching of elderly population.

    PubMed

    Obdrzálek, Stepán; Kurillo, Gregorij; Ofli, Ferda; Bajcsy, Ruzena; Seto, Edmund; Jimison, Holly; Pavel, Michael

    2012-01-01

    The Microsoft Kinect camera is becoming increasingly popular in many areas aside from entertainment, including human activity monitoring and rehabilitation. Many people, however, fail to consider the reliability and accuracy of the Kinect human pose estimation when they depend on it as a measuring system. In this paper we compare the Kinect pose estimation (skeletonization) with more established techniques for pose estimation from motion capture data, examining the accuracy of joint localization and robustness of pose estimation with respect to the orientation and occlusions. We have evaluated six physical exercises aimed at coaching of elderly population. Experimental results present pose estimation accuracy rates and corresponding error bounds for the Kinect system.

  11. Numerical analytic continuation: Answers to well-posed questions

    NASA Astrophysics Data System (ADS)

    Goulko, Olga; Mishchenko, Andrey S.; Pollet, Lode; Prokof'ev, Nikolay; Svistunov, Boris

    2017-01-01

    We formulate the problem of numerical analytic continuation in a way that lets us draw meaningful conclusions about the properties of the spectral function based solely on the input data. Apart from ensuring consistency with the input data (within their error bars) and the a priori and a posteriori (conditional) constraints, it is crucial to reliably characterize the accuracy—or even ambiguity—of the output. We explain how these challenges can be met with two approaches: stochastic optimization with consistent constraints and the modified maximum entropy method. We perform illustrative tests for spectra with a double-peak structure, where we critically examine which spectral properties are accessible (second peak position and its spectral weight) and which ones are lost (second peak width/shape). For an important practical example, we apply our protocol to the Fermi polaron problem.

  12. Dips in Enrollment Posing Challenges for Urban Districts

    ERIC Educational Resources Information Center

    Gehring, John

    2005-01-01

    Across the U.S., urban school districts are losing students and shuttering schools. In Detroit, some 35,000 students have left the city schools in less than a decade, and the city will close 34 schools and reassign more than 10,000 students in 2006. However, the trend is not limited to Rust Belt cities like Detroit, although their problems tend to…

  13. Posing the questions that science has not asked

    SciTech Connect

    Lane, N.

    1995-12-31

    The author addresses the changing environment for research at American universities as they deal with a swiftly changing world. The next few years are viewed as a transition from traditional approaches to university research. Integration of research and teaching is examined since the approach widely varies among colleges and universities. The research infrastructure is viewed as crumbling or obsolete. The role of the National Science Foundation and its methodology for managing research grants is discussed in detail. The nation has real needs and problems in which our scientific laboratories can provide valuable assistance.

  14. A multiscale expectation-maximization semisupervised classifier suitable for badly posed image classification.

    PubMed

    Baraldi, Andrea; Bruzzone, Lorenzo; Blonda, Palma

    2006-08-01

    This paper deals with the problem of badly posed image classification. Although underestimated in practice, bad-posedness is likely to affect many real-world image classification tasks, where reference samples are difficult to collect (e.g., in remote sensing (RS) image mapping) and/or spatial autocorrelation is relevant. In an image classification context affected by a lack of reference samples, an original inductive learning multiscale image classifier, termed multiscale semisupervised expectation maximization (MSEM), is proposed. The rationale behind MSEM is to combine useful complementary properties of two alternative data mapping procedures recently published outside of image processing literature, namely, the multiscale modified Pappas adaptive clustering (MPAC) algorithm and the sample-based semisupervised expectation maximization (SEM) classifier. To demonstrate its potential utility, MSEM is compared against nonstandard classifiers, such as MPAC, SEM and the single-scale contextual SEM (CSEM) classifier, besides against well-known standard classifiers in two RS image classification problems featuring few reference samples and modestly useful texture information. These experiments yield weak (subjective) but numerous quantitative map quality indexes that are consistent with both theoretical considerations and qualitative evaluations by expert photointerpreters. According to these quantitative results, MSEM is competitive in terms of overall image mapping performance at the cost of a computational overhead three to six times superior to that of its most interesting rival, SEM. More in general, our experiments confirm that, even if they rely on heavy class-conditional normal distribution assumptions that may not be true in many real-world problems (e.g., in highly textured images), semisupervised classifiers based on the iterative expectation maximization Gaussian mixture model solution can be very powerful in practice when: 1) there is a lack of reference

  15. Keyframe selection for robust pose estimation in laparoscopic videos

    NASA Astrophysics Data System (ADS)

    von Öhsen, Udo; Marcinczak, Jan Marek; Mármol Vélez, Andres F.; Grigat, Rolf-Rainer

    2012-02-01

    Motion estimation based on point correspondences in two views is a classic problem in computer vision. In the field of laparoscopic video sequences - even with state of the art algorithms - a stable motion estimation can not be guaranteed generally. Typically, a video from a laparoscopic surgery contains sequences where the surgeon barely moves the endoscope. Such restricted movement causes a small ratio between baseline and distance leading to unstable estimation results. Exploiting the fact that the entire sequence is known a priori, we propose an algorithm for keyframe selection in a sequence of images. The key idea can be expressed as follows: if all combination of frames in a sequence are scored, the optimal solution can be described as a weighted directed graph problem. We adapt the widely known Dijkstras Algorithm to find the best selection of frames.1 The framework for keyframe selection can be used universally to find the best combination of frames for any reliable scoring function. For instance, forward motion ensures the most accurate camera position estimation, whereas sideward motion is preferred in the sense of reconstruction. Based on the distribution and the disparity of point correspondences, we propose a scoring function which is capable of detecting poorly conditioned pairs of frames. We demonstrate the potential of the algorithm focusing on accurate camera positions. A robot system provides ground truth data. The environment in laparoscopic videos is reflected by an industrial endoscope and a phantom.

  16. What risks do herbal products pose to the Australian community?

    PubMed

    Byard, Roger W; Musgrave, Ian; Maker, Garth; Bunce, Michael

    2017-02-06

    Traditional herbal products are widely used in Australia to treat a broad range of conditions and diseases. It is popularly believed that these products are safer than prescribed drugs. While many may be safe, it is worrying that the specific effects and harmful interactions of a number of their components with prescription medications is not well understood. Some traditional herbal preparations contain heavy metals and toxic chemicals, as well as naturally occurring organic toxins. The effects of these substances can be dire, including acute hepatic and renal failure, exacerbation of pre-existing conditions and diseases, and even death. The content and quality of herbal preparations are not tightly controlled, with some ingredients either not listed or their concentrations recorded inaccurately on websites or labels. Herbal products may also include illegal ingredients, such as ephedra, Asarum europaeum (European wild ginger) and endangered animal species (eg, snow leopard). An additional problem is augmentation with prescription medications to enhance the apparent effectiveness of a preparation. Toxic substances may also be deliberately or inadvertently added: less expensive, more harmful plants may be substituted for more expensive ingredients, and processing may not be adequate. The lack of regulation and monitoring of traditional herbal preparations in Australia and other Western countries means that their contribution to illness and death is unknown. We need to raise awareness of these problems with health care practitioners and with the general public.

  17. Concentrations of hemoglobin fractions calculation using modified Lambert-Beer law and solving of an ill-posed system of equations

    NASA Astrophysics Data System (ADS)

    Abdallah, Omar; Natsheh, Mohammed; Abo Alam, Kawther; Qananwah, Qasem; Al Nabulsi, Ahmed; Bolz, Armin

    2010-04-01

    Based on the optical methods, it could be able to identify the concentrations of the hemoglobin fractions in a few seconds. An array of Light Emitting Diodes "LEDs" with different wavelengths and a photo detector were used to detect the transmitted or reflected light intensities. A system of equations was built according to the modified Lambert-Beer Law to be solved as an inverse problem. Typically practical inverse problems are all ill-posed. Even well-posed problems may be unstable or ill-conditioned when they digitalized. Also, applications in tissue spectroscopy and optical imaging result in an ill-posed problems. The difficulties involved in solving ill-posed systems are known, where large changes in the solution result from small perturbations in the right hand members of the system that can be caused by measurement tolerance or noise. A good numerical method to solve it may be beneficial in the applications to the optimization problems including linear programming and nonlinear programming. To account for the sensitivity to noise, a regularization method is usually applied to solve this sort of ill-posed problem, where a suitable regularized parameter is used to depress the bias in the computed solution by a better balance of approximation error and propagated data error. The Method has better computational efficiency and accuracy even for the highly ill-conditioned linear equations with a large disturbance on the given data. Comparing the results with that obtained from a direct solution of the system of equations, we prove well-posedness, stability and convergence of the method. The estimated hemoglobin fractions were highly correlated to the reference laboratory measurements.

  18. Prospective evaluation of shape similarity based pose prediction method in D3R Grand Challenge 2015

    NASA Astrophysics Data System (ADS)

    Kumar, Ashutosh; Zhang, Kam Y. J.

    2016-09-01

    Evaluation of ligand three-dimensional (3D) shape similarity is one of the commonly used approaches to identify ligands similar to one or more known active compounds from a library of small molecules. Apart from using ligand shape similarity as a virtual screening tool, its role in pose prediction and pose scoring has also been reported. We have recently developed a method that utilizes ligand 3D shape similarity with known crystallographic ligands to predict binding poses of query ligands. Here, we report the prospective evaluation of our pose prediction method through the participation in drug design data resource (D3R) Grand Challenge 2015. Our pose prediction method was used to predict binding poses of heat shock protein 90 (HSP90) and mitogen activated protein kinase kinase kinase kinase (MAP4K4) ligands and it was able to predict the pose within 2 Å root mean square deviation (RMSD) either as the top pose or among the best of five poses in a majority of cases. Specifically for HSP90 protein, a median RMSD of 0.73 and 0.68 Å was obtained for the top and the best of five predictions respectively. For MAP4K4 target, although the median RMSD for our top prediction was only 2.87 Å but the median RMSD of 1.67 Å for the best of five predictions was well within the limit for successful prediction. Furthermore, the performance of our pose prediction method for HSP90 and MAP4K4 ligands was always among the top five groups. Particularly, for MAP4K4 protein our pose prediction method was ranked number one both in terms of mean and median RMSD when the best of five predictions were considered. Overall, our D3R Grand Challenge 2015 results demonstrated that ligand 3D shape similarity with the crystal ligand is sufficient to predict binding poses of new ligands with acceptable accuracy.

  19. Estimation of Full-Body Poses Using Only Five Inertial Sensors: An Eager or Lazy Learning Approach?

    PubMed Central

    Wouda, Frank J.; Giuberti, Matteo; Bellusci, Giovanni; Veltink, Peter H.

    2016-01-01

    Human movement analysis has become easier with the wide availability of motion capture systems. Inertial sensing has made it possible to capture human motion without external infrastructure, therefore allowing measurements in any environment. As high-quality motion capture data is available in large quantities, this creates possibilities to further simplify hardware setups, by use of data-driven methods to decrease the number of body-worn sensors. In this work, we contribute to this field by analyzing the capabilities of using either artificial neural networks (eager learning) or nearest neighbor search (lazy learning) for such a problem. Sparse orientation features, resulting from sensor fusion of only five inertial measurement units with magnetometers, are mapped to full-body poses. Both eager and lazy learning algorithms are shown to be capable of constructing this mapping. The full-body output poses are visually plausible with an average joint position error of approximately 7 cm, and average joint angle error of 7∘. Additionally, the effects of magnetic disturbances typical in orientation tracking on the estimation of full-body poses was also investigated, where nearest neighbor search showed better performance for such disturbances. PMID:27983676

  20. About well-posed definition of geophysical fields'

    NASA Astrophysics Data System (ADS)

    Ermokhine, Konstantin; Zhdanova, Ludmila; Litvinova, Tamara

    2013-04-01

    We introduce a new approach to the downward continuation of geophysical fields based on approximation of observed data by continued fractions. Key Words: downward continuation, continued fraction, Viskovatov's algorithm. Many papers in geophysics are devoted to the downward continuation of geophysical fields from the earth surface to the lower halfspace. Known obstacle for the method practical use is a field's breaking-down phenomenon near the pole closest to the earth surface. It is explained by the discrepancy of the studied fields' mathematical description: linear presentation of the field in the polynomial form, Taylor or Fourier series, leads to essential and unremovable instability of the inverse problem since the field with specific features in the form of poles in the lower halfspace principally can't be adequately described by the linear construction. Field description by the rational fractions is closer to reality. In this case the presence of function's poles in the lower halfspace corresponds adequately to the denominator zeros. Method proposed below is based on the continued fractions. Let's consider the function measured along the profile and represented it in the form of the Tchebishev series (preliminary reducing the argument to the interval [-1, 1]): There are many variants of power series' presentation by continued fractions. The areas of series and corresponding continued fraction's convergence may differ essentially. As investigations have shown, the most suitable mathematical construction for geophysical fields' continuation is so called general C-fraction: where ( , z designates the depth) For construction of C-fraction corresponding to power series exists a rather effective and stable Viskovatov's algorithm (Viskovatov B. "De la methode generale pour reduire toutes sortes des quantitees en fraction continues". Memoires de l' Academie Imperiale des Sciences de St. Petersburg, 1, 1805). A fundamentally new algorithm for Downward Continuation

  1. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing...

  2. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing...

  3. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing...

  4. Metacognition in Chemical Education: Question Posing in the Case-Based Computerized Learning Environment

    ERIC Educational Resources Information Center

    Kaberman, Zvia; Dori, Yehudit Judy

    2009-01-01

    Posing questions about an article might improve one's knowledge--a cognitive function, or monitor one's thought processes--a metacognitive function. This study focuses on guided question posing while using a metacognitive strategy by 12th grade honors chemistry students. We investigated the ways by which the metacognitive strategy affected…

  5. Question-Posing Capability as an Alternative Evaluation Method: Analysis of an Environmental Case Study.

    ERIC Educational Resources Information Center

    Dori, Yehudit J.; Herscovitz, Orit

    1999-01-01

    Presents research on the scientific question-posing capabilities of 10th-grade students (n=127) who were studying air quality in a cooperative way using the jigsaw method. Finds that the difference between students at high and low academic levels to the extent of increase in both number and complexity of posed questions was significant. Contains…

  6. Weak evidence on nalmefene creates dilemmas for clinicians and poses questions for regulators and researchers

    PubMed Central

    Angus, Kathryn; Elders, Andrew; de Andrade, Marisa; Raistrick, Duncan; Heather, Nick; McCambridge, Jim

    2016-01-01

    Abstract Background and aims Nalmefene has been approved in Europe for the treatment of alcohol dependence and subsequently recommended by the UK National Institute for Health and Care Excellence (NICE). This study examines critically the evidence base underpinning both decisions and the issues arising. Methods Published studies of nalmefene were identified through a systematic search, with documents from the European Medicines Agency, the NICE appraisal and public clinical trial registries also examined to identify methodological issues. Results Efficacy data used to support the licensing of nalmefene suffer from risk of bias due to lack of specification of a priori outcome measures and sensitivity analyses, use of post‐hoc sample refinement and the use of inappropriate comparators. Despite this, evidence for the efficacy of nalmefene in reducing alcohol consumption in those with alcohol dependence is, at best, modest, and of uncertain significance to individual patients. The relevance of existing trial data to routine primary care practice is doubtful. Conclusions Problems with the registration, design, analysis and reporting of clinical trials of nalmefene did not prevent it being licensed and recommended for treating alcohol dependence. This creates dilemmas for primary care clinicians and commissioning organisations where nalmefene has been heavily promoted, and poses wider questions about the effectiveness of the medicines regulation system and how to develop the alcohol treatment evidence base. PMID:27262594

  7. The Spatial and the Visual in Mental Spatial Reasoning: An Ill-Posed Distinction

    NASA Astrophysics Data System (ADS)

    Schultheis, Holger; Bertel, Sven; Barkowsky, Thomas; Seifert, Inessa

    It is an ongoing and controversial debate in cognitive science which aspects of knowledge humans process visually and which ones they process spatially. Similarly, artificial intelligence (AI) and cognitive science research, in building computational cognitive systems, tended to use strictly spatial or strictly visual representations. The resulting systems, however, were suboptimal both with respect to computational efficiency and cognitive plau sibility. In this paper, we propose that the problems in both research strands stem from a mis conception of the visual and the spatial in mental spatial knowl edge pro cessing. Instead of viewing the visual and the spatial as two clearly separable categories, they should be conceptualized as the extremes of a con tinuous dimension of representation. Regarding psychology, a continuous di mension avoids the need to exclusively assign processes and representations to either one of the cate gories and, thus, facilitates a more unambiguous rating of processes and rep resentations. Regarding AI and cognitive science, the con cept of a continuous spatial / visual dimension provides the possibility of rep re sentation structures which can vary continuously along the spatial / visual di mension. As a first step in exploiting these potential advantages of the pro posed conception we (a) introduce criteria allowing for a non-dichotomic judgment of processes and representations and (b) present an approach towards rep re sentation structures that can flexibly vary along the spatial / visual dimension.

  8. Head Pose Estimation Using Multilinear Subspace Analysis for Robot Human Awareness

    NASA Technical Reports Server (NTRS)

    Ivanov, Tonislav; Matthies, Larry; Vasilescu, M. Alex O.

    2009-01-01

    Mobile robots, operating in unconstrained indoor and outdoor environments, would benefit in many ways from perception of the human awareness around them. Knowledge of people's head pose and gaze directions would enable the robot to deduce which people are aware of the its presence, and to predict future motions of the people for better path planning. To make such inferences, requires estimating head pose on facial images that are combination of multiple varying factors, such as identity, appearance, head pose, and illumination. By applying multilinear algebra, the algebra of higher-order tensors, we can separate these factors and estimate head pose regardless of subject's identity or image conditions. Furthermore, we can automatically handle uncertainty in the size of the face and its location. We demonstrate a pipeline of on-the-move detection of pedestrians with a robot stereo vision system, segmentation of the head, and head pose estimation in cluttered urban street scenes.

  9. Foot Pose Estimation Using an Inertial Sensor Unit and Two Distance Sensors

    PubMed Central

    Duong, Pham Duy; Suh, Young Soo

    2015-01-01

    There are many inertial sensor-based foot pose estimation algorithms. In this paper, we present a methodology to improve the accuracy of foot pose estimation using two low-cost distance sensors (VL6180) in addition to an inertial sensor unit. The distance sensor is a time-of-flight range finder and can measure distance up to 20 cm. A Kalman filter with 21 states is proposed to estimate both the calibration parameter (relative pose of distance sensors with respect to the inertial sensor unit) and foot pose. Once the calibration parameter is obtained, a Kalman filter with nine states can be used to estimate foot pose. Through four activities (walking, dancing step, ball kicking, jumping), it is shown that the proposed algorithm significantly improves the vertical position estimation. PMID:26151205

  10. Foot Pose Estimation Using an Inertial Sensor Unit and Two Distance Sensors.

    PubMed

    Duong, Pham Duy; Suh, Young Soo

    2015-07-03

    There are many inertial sensor-based foot pose estimation algorithms. In this paper, we present a methodology to improve the accuracy of foot pose estimation using two low-cost distance sensors (VL6180) in addition to an inertial sensor unit. The distance sensor is a time-of-flight range finder and can measure distance up to 20 cm. A Kalman filter with 21 states is proposed to estimate both the calibration parameter (relative pose of distance sensors with respect to the inertial sensor unit) and foot pose. Once the calibration parameter is obtained, a Kalman filter with nine states can be used to estimate foot pose. Through four activities (walking, dancing step, ball kicking, jumping), it is shown that the proposed algorithm significantly improves the vertical position estimation.

  11. Improving docking results via reranking of ensembles of ligand poses in multiple X-ray protein conformations with MM-GBSA.

    PubMed

    Greenidge, P A; Kramer, C; Mozziconacci, J-C; Sherman, W

    2014-10-27

    There is a tendency in the literature to be critical of scoring functions when docking programs perform poorly. The assumption is that existing scoring functions need to be enhanced or new ones developed in order to improve the performance of docking programs for tasks such as pose prediction and virtual screening. However, failures can result from either sampling or scoring (or a combination of the two), although less emphasis tends to be given to the former. In this work, we use the programs GOLD and Glide on a high-quality data set to explore whether failures in pose prediction and binding affinity estimation can be attributable more to sampling or scoring. We show that identification of the correct pose (docking power) can be improved by incorporating ligand strain into the scoring function or rescoring an ensemble of diverse docking poses with MM-GBSA in a postprocessing step. We explore the use of nondefault docking settings and find that enhancing ligand sampling also improves docking power, again suggesting that sampling is more limiting than scoring for the docking programs investigated in this work. In cross-docking calculations (docking a ligand to a noncognate receptor structure) we observe a significant reduction in the accuracy of pose ranking, as expected and has been reported by others; however, we demonstrate that these alternate poses may in fact be more complementary between the ligand and the rigid receptor conformation, emphasizing that treating the receptor rigidly is an artificial constraint on the docking problem. We simulate protein flexibility by the use of multiple crystallographic conformations of a protein and demonstrate that docking results can be improved with this level of protein sampling. This work indicates the need for better sampling in docking programs, especially for the receptor. This study also highlights the variable descriptive value of RMSD as the sole arbiter of pose replication quality. It is shown that ligand poses

  12. Stereovision-based pose and inertia estimation of unknown and uncooperative space objects

    NASA Astrophysics Data System (ADS)

    Pesce, Vincenzo; Lavagna, Michèle; Bevilacqua, Riccardo

    2017-01-01

    Autonomous close proximity operations are an arduous and attractive problem in space mission design. In particular, the estimation of pose, motion and inertia properties of an uncooperative object is a challenging task because of the lack of available a priori information. This paper develops a novel method to estimate the relative position, velocity, angular velocity, attitude and the ratios of the components of the inertia matrix of an uncooperative space object using only stereo-vision measurements. The classical Extended Kalman Filter (EKF) and an Iterated Extended Kalman Filter (IEKF) are used and compared for the estimation procedure. In addition, in order to compute the inertia properties, the ratios of the inertia components are added to the state and a pseudo-measurement equation is considered in the observation model. The relative simplicity of the proposed algorithm could be suitable for an online implementation for real applications. The developed algorithm is validated by numerical simulations in MATLAB using different initial conditions and uncertainty levels. The goal of the simulations is to verify the accuracy and robustness of the proposed estimation algorithm. The obtained results show satisfactory convergence of estimation errors for all the considered quantities. The obtained results, in several simulations, shows some improvements with respect to similar works, which deal with the same problem, present in literature. In addition, a video processing procedure is presented to reconstruct the geometrical properties of a body using cameras. This inertia reconstruction algorithm has been experimentally validated at the ADAMUS (ADvanced Autonomous MUltiple Spacecraft) Lab at the University of Florida. In the future, this different method could be integrated to the inertia ratios estimator to have a complete tool for mass properties recognition.

  13. Robust 3D object localization and pose estimation for random bin picking with the 3DMaMa algorithm

    NASA Astrophysics Data System (ADS)

    Skotheim, Øystein; Thielemann, Jens T.; Berge, Asbjørn; Sommerfelt, Arne

    2010-02-01

    Enabling robots to automatically locate and pick up randomly placed and oriented objects from a bin is an important challenge in factory automation, replacing tedious and heavy manual labor. A system should be able to recognize and locate objects with a predefined shape and estimate the position with the precision necessary for a gripping robot to pick it up. We describe a system that consists of a structured light instrument for capturing 3D data and a robust approach for object location and pose estimation. The method does not depend on segmentation of range images, but instead searches through pairs of 2D manifolds to localize candidates for object match. This leads to an algorithm that is not very sensitive to scene complexity or the number of objects in the scene. Furthermore, the strategy for candidate search is easily reconfigurable to arbitrary objects. Experiments reported in this paper show the utility of the method on a general random bin picking problem, in this paper exemplified by localization of car parts with random position and orientation. Full pose estimation is done in less than 380 ms per image. We believe that the method is applicable for a wide range of industrial automation problems where precise localization of 3D objects in a scene is needed.

  14. Research Mathematicians' Practices in Selecting Mathematical Problems

    ERIC Educational Resources Information Center

    Misfeldt, Morten; Johansen, Mikkel Willum

    2015-01-01

    Developing abilities to create, inquire into, qualify, and choose among mathematical problems is an important educational goal. In this paper, we elucidate how mathematicians work with mathematical problems in order to understand this mathematical process. More specifically, we investigate how mathematicians select and pose problems and discuss to…

  15. The Coffee-Milk Mixture Problem Revisited

    ERIC Educational Resources Information Center

    Marion, Charles F.

    2015-01-01

    This analysis of a problem that is frequently posed at professional development workshops, in print, and on the Web--the coffee-milk mixture riddle--illustrates the timeless advice of George Pólya's masterpiece on problem solving in mathematics, "How to Solve It." In his book, Pólya recommends that problems previously solved and put…

  16. Can Holo NMR Chemical Shifts be Directly Used to Resolve RNA-Ligand Poses?

    PubMed

    Frank, Aaron T

    2016-02-22

    Using a set of machine learning based predictors that are capable of predicting ligand-induced shielding effects on (1)H and (13)C nonexchangeable nuclei, it was discovered that holo NMR chemical shifts can be used to resolve RNA-ligand poses. This was accomplished by quantitatively comparing measured and predicted holo chemical shifts in conformationally diverse "decoy" pools for three test cases and then, for each, comparing the native pose to the pose in the decoy pool that exhibited the lowest error. For three test cases, the poses in the decoy pools that exhibited the best agreement between measured and predicted holo chemical shifts were within 0.28, 1.12, and 2.38 Å of the native poses. Interestingly, the predictors used in this study were trained on a database containing, only, apo RNA data. The agreement between the chemical shift-selected poses and the native NMR poses suggests that the predictors used in this study were able to "learn" general chemical shift-structure relationships from apo RNA data that could be used to account for ligand-induced shielding effects on RNA nuclei for the test cases studied.

  17. Monocular-Based 6-Degree of Freedom Pose Estimation Technology for Robotic Intelligent Grasping Systems.

    PubMed

    Liu, Tao; Guo, Yin; Yang, Shourui; Yin, Shibin; Zhu, Jigui

    2017-02-14

    Industrial robots are expected to undertake ever more advanced tasks in the modern manufacturing industry, such as intelligent grasping, in which robots should be capable of recognizing the position and orientation of a part before grasping it. In this paper, a monocular-based 6-degree of freedom (DOF) pose estimation technology to enable robots to grasp large-size parts at informal poses is proposed. A camera was mounted on the robot end-flange and oriented to measure several featured points on the part before the robot moved to grasp it. In order to estimate the part pose, a nonlinear optimization model based on the camera object space collinearity error in different poses is established, and the initial iteration value is estimated with the differential transformation. Measuring poses of the camera are optimized based on uncertainty analysis. Also, the principle of the robotic intelligent grasping system was developed, with which the robot could adjust its pose to grasp the part. In experimental tests, the part poses estimated with the method described in this paper were compared with those produced by a laser tracker, and results show the RMS angle and position error are about 0.0228° and 0.4603 mm. Robotic intelligent grasping tests were also successfully performed in the experiments.

  18. A Gaussian process guided particle filter for tracking 3D human pose in video.

    PubMed

    Sedai, Suman; Bennamoun, Mohammed; Huynh, Du Q

    2013-11-01

    In this paper, we propose a hybrid method that combines Gaussian process learning, a particle filter, and annealing to track the 3D pose of a human subject in video sequences. Our approach, which we refer to as annealed Gaussian process guided particle filter, comprises two steps. In the training step, we use a supervised learning method to train a Gaussian process regressor that takes the silhouette descriptor as an input and produces multiple output poses modeled by a mixture of Gaussian distributions. In the tracking step, the output pose distributions from the Gaussian process regression are combined with the annealed particle filter to track the 3D pose in each frame of the video sequence. Our experiments show that the proposed method does not require initialization and does not lose tracking of the pose. We compare our approach with a standard annealed particle filter using the HumanEva-I dataset and with other state of the art approaches using the HumanEva-II dataset. The evaluation results show that our approach can successfully track the 3D human pose over long video sequences and give more accurate pose tracking results than the annealed particle filter.

  19. Using Facial Symmetry to Handle Pose Variations in Real-World 3D Face Recognition.

    PubMed

    Passalis, Georgios; Perakis, Panagiotis; Theoharis, Theoharis; Kakadiaris, Ioannis A

    2011-10-01

    The uncontrolled conditions of real-world biometric applications pose a great challenge to any face recognition approach. The unconstrained acquisition of data from uncooperative subjects may result in facial scans with significant pose variations along the yaw axis. Such pose variations can cause extensive occlusions, resulting in missing data. In this paper, a novel 3D face recognition method is proposed that uses facial symmetry to handle pose variations. It employs an automatic landmark detector that estimates pose and detects occluded areas for each facial scan. Subsequently, an Annotated Face Model is registered and fitted to the scan. During fitting, facial symmetry is used to overcome the challenges of missing data. The result is a pose invariant geometry image. Unlike existing methods that require frontal scans, the proposed method performs comparisons among interpose scans using a wavelet-based biometric signature. It is suitable for real-world applications as it only requires half of the face to be visible to the sensor. The proposed method was evaluated using databases from the University of Notre Dame and the University of Houston that, to the best of our knowledge, include the most challenging pose variations publicly available. The average rank-one recognition rate of the proposed method in these databases was 83.7 percent.

  20. Fine-grained bird recognition by using contour-based pose transfer

    NASA Astrophysics Data System (ADS)

    Zhu, Leqing; Lv, Yaoyao; Zhang, Daxing; Zhou, Yadong; Yan, Guoli; Wang, Huiyan; Wang, Xun

    2015-10-01

    We propose a pose transfer method for fine-grained classifications of birds that have wide variations in appearance due to different poses and subcategories. Specifically, bird pose is transferred by using Radon-transform-based contour descriptor, k-means clustering, and K nearest neighbors (KNN) classifier. During training, we clustered annotated image samples into certain poses based on their normalized part locations and used the cluster centers as their consistent part constellations for a particular pose. At the testing stage, Radon-transform-based contour descriptor is used to find the pose a sample belongs to with a KNN classifier by using cosine similarity, and normalized part constellations are transferred to the unannotated image according to the pose type. Bag-of-visual words with OpponentSIFT and color names extracted from each part and from the global image are concatenated as feature vector, which is input to support vector machine for classification. Experimental results demonstrate significant performance gains from our method on the Caltech-UCSD Birds-2011 dataset for the fine-grained bird classification task.

  1. Monocular-Based 6-Degree of Freedom Pose Estimation Technology for Robotic Intelligent Grasping Systems

    PubMed Central

    Liu, Tao; Guo, Yin; Yang, Shourui; Yin, Shibin; Zhu, Jigui

    2017-01-01

    Industrial robots are expected to undertake ever more advanced tasks in the modern manufacturing industry, such as intelligent grasping, in which robots should be capable of recognizing the position and orientation of a part before grasping it. In this paper, a monocular-based 6-degree of freedom (DOF) pose estimation technology to enable robots to grasp large-size parts at informal poses is proposed. A camera was mounted on the robot end-flange and oriented to measure several featured points on the part before the robot moved to grasp it. In order to estimate the part pose, a nonlinear optimization model based on the camera object space collinearity error in different poses is established, and the initial iteration value is estimated with the differential transformation. Measuring poses of the camera are optimized based on uncertainty analysis. Also, the principle of the robotic intelligent grasping system was developed, with which the robot could adjust its pose to grasp the part. In experimental tests, the part poses estimated with the method described in this paper were compared with those produced by a laser tracker, and results show the RMS angle and position error are about 0.0228° and 0.4603 mm. Robotic intelligent grasping tests were also successfully performed in the experiments. PMID:28216555

  2. Head Pose Estimation on Eyeglasses Using Line Detection and Classification Approach

    NASA Astrophysics Data System (ADS)

    Setthawong, Pisal; Vannija, Vajirasak

    This paper proposes a unique approach for head pose estimation of subjects with eyeglasses by using a combination of line detection and classification approaches. Head pose estimation is considered as an important non-verbal form of communication and could also be used in the area of Human-Computer Interface. A major improvement of the proposed approach is that it allows estimation of head poses at a high yaw/pitch angle when compared with existing geometric approaches, does not require expensive data preparation and training, and is generally fast when compared with other approaches.

  3. Nearby Day Cares Don't Pose Health Risks to Kids

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_164109.html Nearby Day Cares Don't Pose Health Risks to Kids: ... March 15, 2017 (HealthDay News) -- Living near a day care center won't increase your child's risk ...

  4. Estimating aquatic hazards posed by prescription pharmaceutical residues from municipal wastewater

    EPA Science Inventory

    Risks posed by pharmaceuticals in the environment are hard to estimate due to limited monitoring capacity and difficulty interpreting monitoring results. In order to partially address these issues, we suggest a method for prioritizing pharmaceuticals for monitoring, and a framewo...

  5. Improved pose and affinity predictions using different protocols tailored on the basis of data availability

    NASA Astrophysics Data System (ADS)

    Prathipati, Philip; Nagao, Chioko; Ahmad, Shandar; Mizuguchi, Kenji

    2016-09-01

    The D3R 2015 grand drug design challenge provided a set of blinded challenges for evaluating the applicability of our protocols for pose and affinity prediction. In the present study, we report the application of two different strategies for the two D3R protein targets HSP90 and MAP4K4. HSP90 is a well-studied target system with numerous co-crystal structures and SAR data. Furthermore the D3R HSP90 test compounds showed high structural similarity to existing HSP90 inhibitors in BindingDB. Thus, we adopted an integrated docking and scoring approach involving a combination of both pharmacophoric and heavy atom similarity alignments, local minimization and quantitative structure activity relationships modeling, resulting in the reasonable prediction of pose [with the root mean square deviation (RMSD) values of 1.75 Å for mean pose 1, 1.417 Å for the mean best pose and 1.85 Å for the mean all poses] and affinity (ROC AUC = 0.702 at 7.5 pIC50 cut-off and R = 0.45 for 180 compounds). The second protein, MAP4K4, represents a novel system with limited SAR and co-crystal structure data and little structural similarity of the D3R MAP4K4 test compounds to known MAP4K4 ligands. For this system, we implemented an exhaustive pose and affinity prediction protocol involving docking and scoring using the PLANTS software which considers side chain flexibility together with protein-ligand fingerprints analysis assisting in pose prioritization. This protocol through fares poorly in pose prediction (with the RMSD values of 4.346 Å for mean pose 1, 4.69 Å for mean best pose and 4.75 Å for mean all poses) and produced reasonable affinity prediction (AUC = 0.728 at 7.5 pIC50 cut-off and R = 0.67 for 18 compounds, ranked 1st among 80 submissions).

  6. STS-26 crewmembers pose for onboard portrait on middeck with 51L mementos

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 crewmembers, each wearing a red, white, or blue polo shirt, pose for onboard crew portrait on Discovery's, Orbiter Vehicle (OV) 103's, middeck with STS-51L crew portrait, its flight (crew) insignia, and the STS-26 flight (crew) insignia. Left to right are Mission Specialist (MS) David C. Hilmers, MS George D. Nelson, Commander Frederick H. Hauck, MS John M. Lounge, and Pilot Richard O. Covey (front). The crewmembers pose in front of the port side wall.

  7. Consistently Showing Your Best Side? Intra-individual Consistency in #Selfie Pose Orientation

    PubMed Central

    Lindell, Annukka K.

    2017-01-01

    Painted and photographic portraits of others show an asymmetric bias: people favor their left cheek. Both experimental and database studies confirm that the left cheek bias extends to selfies. To date all such selfie studies have been cross-sectional; whether individual selfie-takers tend to consistently favor the same pose orientation, or switch between multiple poses, remains to be determined. The present study thus examined intra-individual consistency in selfie pose orientations. Two hundred selfie-taking participants (100 male and 100 female) were identified by searching #selfie on Instagram. The most recent 10 single-subject selfies for the each of the participants were selected and coded for type of selfie (normal; mirror) and pose orientation (left, midline, right), resulting in a sample of 2000 selfies. Results indicated that selfie-takers do tend to consistently adopt a preferred pose orientation (α = 0.72), with more participants showing an overall left cheek bias (41%) than would be expected by chance (overall right cheek bias = 31.5%; overall midline bias = 19.5%; no overall bias = 8%). Logistic regression modellng, controlling for the repeated measure of participant identity, indicated that sex did not affect pose orientation. However, selfie type proved a significant predictor when comparing left and right cheek poses, with a stronger left cheek bias for mirror than normal selfies. Overall, these novel findings indicate that selfie-takers show intra-individual consistency in pose orientation, and in addition, replicate the previously reported left cheek bias for selfies and other types of portrait, confirming that the left cheek bias also presents within individuals’ selfie corpora. PMID:28270790

  8. Automatic pose correction for image-guided nonhuman primate brain surgery planning

    NASA Astrophysics Data System (ADS)

    Ghafurian, Soheil; Chen, Antong; Hines, Catherine; Dogdas, Belma; Bone, Ashleigh; Lodge, Kenneth; O'Malley, Stacey; Winkelmann, Christopher T.; Bagchi, Ansuman; Lubbers, Laura S.; Uslaner, Jason M.; Johnson, Colena; Renger, John; Zariwala, Hatim A.

    2016-03-01

    Intracranial delivery of recombinant DNA and neurochemical analysis in nonhuman primate (NHP) requires precise targeting of various brain structures via imaging derived coordinates in stereotactic surgeries. To attain targeting precision, the surgical planning needs to be done on preoperative three dimensional (3D) CT and/or MR images, in which the animals head is fixed in a pose identical to the pose during the stereotactic surgery. The matching of the image to the pose in the stereotactic frame can be done manually by detecting key anatomical landmarks on the 3D MR and CT images such as ear canal and ear bar zero position. This is not only time intensive but also prone to error due to the varying initial poses in the images which affects both the landmark detection and rotation estimation. We have introduced a fast, reproducible, and semi-automatic method to detect the stereotactic coordinate system in the image and correct the pose. The method begins with a rigid registration of the subject images to an atlas and proceeds to detect the anatomical landmarks through a sequence of optimization, deformable and multimodal registration algorithms. The results showed similar precision (maximum difference of 1.71 in average in-plane rotation) to a manual pose correction.

  9. Comparative assessment of techniques for initial pose estimation using monocular vision

    NASA Astrophysics Data System (ADS)

    Sharma, Sumant; D`Amico, Simone

    2016-06-01

    This work addresses the comparative assessment of initial pose estimation techniques for monocular navigation to enable formation-flying and on-orbit servicing missions. Monocular navigation relies on finding an initial pose, i.e., a coarse estimate of the attitude and position of the space resident object with respect to the camera, based on a minimum number of features from a three dimensional computer model and a single two dimensional image. The initial pose is estimated without the use of fiducial markers, without any range measurements or any apriori relative motion information. Prior work has been done to compare different pose estimators for terrestrial applications, but there is a lack of functional and performance characterization of such algorithms in the context of missions involving rendezvous operations in the space environment. Use of state-of-the-art pose estimation algorithms designed for terrestrial applications is challenging in space due to factors such as limited on-board processing power, low carrier to noise ratio, and high image contrasts. This paper focuses on performance characterization of three initial pose estimation algorithms in the context of such missions and suggests improvements.

  10. A new pose measurement system based on orthogonal beam splitting imaging configuration

    NASA Astrophysics Data System (ADS)

    Liu, Xintong; Sun, Changku; Wang, Peng

    2015-08-01

    A new pose measurement system based on orthogonal beam splitting imaging is proposed in this paper to solve the contradictions between the measurement accuracy and measurement speed in the existing pose measurement method of monocular or binocular vision with multi-linear CCDs. In the system, monocular object lens with beam splitting structure and two linear CCDs are combined to compose the pose measurement sensor. Monocular camera helps the system gain a large field of view. And the two orthogonally placed linear CCDs are equal to one array CCD. Furthermore, linear CCD possesses the advantage of high-resolution imaging, high-speed data capturing and high-efficiency data processing as compared to an array one. The key work of this paper lies in designing the optical structure of the sensor, calibrating the parameters of the camera corresponding to its model, and solving pose of the object by corresponding position algorithm. The experimental results prove that the measurement accuracy (2%) of orthogonally-splitting-imaging pose sensor can be achieved. Hence, this system meets the high-speed and high-precision measurement requirements in wide space and can be applied to pose measurement in aerospace and vehicle field.

  11. Problemes poses par la mesure du rendement en francais des eleves franco-ontariens (Problems Posed by the Measurement of Proficiency in French Among Franco-Ontarian Students). Working Papers on Bilingualism, No. 16.

    ERIC Educational Resources Information Center

    Canale, Michael; Mougeon, Raymond

    This study examines the hypothesis that the French used by a large number of Franco-Ontarians represents a linguistic system (or several systems) that differs from Standard French. In addition, a review of previous research leads to the inverse hypothesis, that Ontarian French represents a body of different systems or sub-systems that are more or…

  12. A well-posed numerical method to track isolated conformal map singularities in Hele-Shaw flow

    NASA Technical Reports Server (NTRS)

    Baker, Gregory; Siegel, Michael; Tanveer, Saleh

    1995-01-01

    We present a new numerical method for calculating an evolving 2D Hele-Shaw interface when surface tension effects are neglected. In the case where the flow is directed from the less viscous fluid into the more viscous fluid, the motion of the interface is ill-posed; small deviations in the initial condition will produce significant changes in the ensuing motion. This situation is disastrous for numerical computation, as small round-off errors can quickly lead to large inaccuracies in the computed solution. Our method of computation is most easily formulated using a conformal map from the fluid domain into a unit disk. The method relies on analytically continuing the initial data and equations of motion into the region exterior to the disk, where the evolution problem becomes well-posed. The equations are then numerically solved in the extended domain. The presence of singularities in the conformal map outside of the disk introduces specific structures along the fluid interface. Our method can explicitly track the location of isolated pole and branch point singularities, allowing us to draw connections between the development of interfacial patterns and the motion of singularities as they approach the unit disk. In particular, we are able to relate physical features such as finger shape, side-branch formation, and competition between fingers to the nature and location of the singularities. The usefulness of this method in studying the formation of topological singularities (self-intersections of the interface) is also pointed out.

  13. Numerical reconstruction of photon-number statistics from photocounting statistics: Regularization of an ill-posed problem

    SciTech Connect

    Starkov, V. N.; Semenov, A. A.; Gomonay, H. V.

    2009-07-15

    We demonstrate a practical possibility of loss compensation in measured photocounting statistics in the presence of dark counts and background radiation noise. It is shown that satisfactory results are obtained even in the case of low detection efficiency and large experimental errors.

  14. [Selected problems in the forensic-psychiatric evaluation of persons posing a likelihood of repeating a criminal act].

    PubMed

    Florkowski, Antoni; Zboralski, Krzysztof; Nowacka, Agata; Strójwas, Krzysztof; Flinik-Jankowska, Magdalena; Konopa, Aleksandra; Łacisz, Joanna; Wierzbiński, Piotr

    2014-09-01

    In the current penal code, compared to previous regulations, there have been alterations concerning medical security measures. These amendments have been prompted by socio-politic circumstances in Poland as well as implementation of Mental Health Act. According to the current law the court, on the request of expert psychiatrists, can pronounce a sentence of obligatory stay in psychiatric institution for perpetrator of criminal act who has been deemed not sane due to 31 subsection 1 of penal code and who is predictably able of recidivism. In legal-medical practice those less experienced expert psychiatrists may encounter difficulties producing expertise for the court, especially evaluating probability of recurrence of committing a criminal act and resulting request for psychiatric detention. In order to make this issue more acquainted we present a review of literature concerning it.

  15. Problem-Posing in a Primary Grade Classroom: Utilizing Freire's Methods to Break the Culture of Silence

    ERIC Educational Resources Information Center

    Reed, Judith; Saunders, Karen; Pfadenhauer-Simonds, Susan

    2015-01-01

    Using Paulo Freire's, idea that the aim of education must always be to transform the world so as to liberate oppressed peoples. The authors: Reed, Saunders, and Pfadenhauer-Simonds address this issue by noting that state-backed education systems in the United States, as elsewhere, arguably can be seen as supporting repressive forces that keep…

  16. Reflective Analysis as a Tool for Task Redesign: The Case of Prospective Elementary Teachers Solving and Posing Fraction Comparison Problems

    ERIC Educational Resources Information Center

    Thanheiser, Eva; Olanoff, Dana; Hillen, Amy; Feldman, Ziv; Tobias, Jennifer M.; Welder, Rachael M.

    2016-01-01

    Mathematical task design has been a central focus of the mathematics education research community over the last few years. In this study, six university teacher educators from six different US institutions formed a community of practice to explore key aspects of task design (planning, implementing, reflecting, and modifying) in the context of…

  17. Current Aeromedical Issues in Rotary Wing Operations. (Problemes actuels de medecine aeronautique poses par les operations utilisant des voilures tournantes)

    DTIC Science & Technology

    1999-08-01

    specific duration. Such Technical Teams can organise workshops, symposia, field trials, lecture series and training courses. An important function of...is used fluctuations in communications patterns, for given information of the functional status of suggesting the potential utility of the system the...no change of heading or height. Both the deceleration and the function . nose-up pitch associated with the attitude change at the final stages of

  18. Problem Solving

    ERIC Educational Resources Information Center

    Kinsella, John J.

    1970-01-01

    Discussed are the nature of a mathematical problem, problem solving in the traditional and modern mathematics programs, problem solving and psychology, research related to problem solving, and teaching problem solving in algebra and geometry. (CT)

  19. Exercise Sensing and Pose Recovery Inference Tool (ESPRIT) - A Compact Stereo-based Motion Capture Solution For Exercise Monitoring

    NASA Technical Reports Server (NTRS)

    Lee, Mun Wai

    2015-01-01

    Crew exercise is important during long-duration space flight not only for maintaining health and fitness but also for preventing adverse health problems, such as losses in muscle strength and bone density. Monitoring crew exercise via motion capture and kinematic analysis aids understanding of the effects of microgravity on exercise and helps ensure that exercise prescriptions are effective. Intelligent Automation, Inc., has developed ESPRIT to monitor exercise activities, detect body markers, extract image features, and recover three-dimensional (3D) kinematic body poses. The system relies on prior knowledge and modeling of the human body and on advanced statistical inference techniques to achieve robust and accurate motion capture. In Phase I, the company demonstrated motion capture of several exercises, including walking, curling, and dead lifting. Phase II efforts focused on enhancing algorithms and delivering an ESPRIT prototype for testing and demonstration.

  20. Combining in silico and in cerebro approaches for virtual screening and pose prediction in SAMPL4.

    PubMed

    Voet, Arnout R D; Kumar, Ashutosh; Berenger, Francois; Zhang, Kam Y J

    2014-04-01

    The SAMPL challenges provide an ideal opportunity for unbiased evaluation and comparison of different approaches used in computational drug design. During the fourth round of this SAMPL challenge, we participated in the virtual screening and binding pose prediction on inhibitors targeting the HIV-1 integrase enzyme. For virtual screening, we used well known and widely used in silico methods combined with personal in cerebro insights and experience. Regular docking only performed slightly better than random selection, but the performance was significantly improved upon incorporation of additional filters based on pharmacophore queries and electrostatic similarities. The best performance was achieved when logical selection was added. For the pose prediction, we utilized a similar consensus approach that amalgamated the results of the Glide-XP docking with structural knowledge and rescoring. The pose prediction results revealed that docking displayed reasonable performance in predicting the binding poses. However, prediction performance can be improved utilizing scientific experience and rescoring approaches. In both the virtual screening and pose prediction challenges, the top performance was achieved by our approaches. Here we describe the methods and strategies used in our approaches and discuss the rationale of their performances.

  1. An eye model for uncalibrated eye gaze estimation under variable head pose

    NASA Astrophysics Data System (ADS)

    Hnatow, Justin; Savakis, Andreas

    2007-04-01

    Gaze estimation is an important component of computer vision systems that monitor human activity for surveillance, human-computer interaction, and various other applications including iris recognition. Gaze estimation methods are particularly valuable when they are non-intrusive, do not require calibration, and generalize well across users. This paper presents a novel eye model that is employed for efficiently performing uncalibrated eye gaze estimation. The proposed eye model was constructed from a geometric simplification of the eye and anthropometric data about eye feature sizes in order to circumvent the requirement of calibration procedures for each individual user. The positions of the two eye corners and the midpupil, the distance between the two eye corners, and the radius of the eye sphere are required for gaze angle calculation. The locations of the eye corners and midpupil are estimated via processing following eye detection, and the remaining parameters are obtained from anthropometric data. This eye model is easily extended to estimating eye gaze under variable head pose. The eye model was tested on still images of subjects at frontal pose (0 °) and side pose (34 °). An upper bound of the model's performance was obtained by manually selecting the eye feature locations. The resulting average absolute error was 2.98 ° for frontal pose and 2.87 ° for side pose. The error was consistent across subjects, which indicates that good generalization was obtained. This level of performance compares well with other gaze estimation systems that utilize a calibration procedure to measure eye features.

  2. Constructing a Database from Multiple 2D Images for Camera Pose Estimation and Robot Localization

    NASA Technical Reports Server (NTRS)

    Wolf, Michael; Ansar, Adnan I.; Brennan, Shane; Clouse, Daniel S.; Padgett, Curtis W.

    2012-01-01

    The LMDB (Landmark Database) Builder software identifies persistent image features (landmarks) in a scene viewed multiple times and precisely estimates the landmarks 3D world positions. The software receives as input multiple 2D images of approximately the same scene, along with an initial guess of the camera poses for each image, and a table of features matched pair-wise in each frame. LMDB Builder aggregates landmarks across an arbitrarily large collection of frames with matched features. Range data from stereo vision processing can also be passed to improve the initial guess of the 3D point estimates. The LMDB Builder aggregates feature lists across all frames, manages the process to promote selected features to landmarks, and iteratively calculates the 3D landmark positions using the current camera pose estimations (via an optimal ray projection method), and then improves the camera pose estimates using the 3D landmark positions. Finally, it extracts image patches for each landmark from auto-selected key frames and constructs the landmark database. The landmark database can then be used to estimate future camera poses (and therefore localize a robotic vehicle that may be carrying the cameras) by matching current imagery to landmark database image patches and using the known 3D landmark positions to estimate the current pose.

  3. A pose estimation method for unmanned ground vehicles in GPS denied environments

    NASA Astrophysics Data System (ADS)

    Tamjidi, Amirhossein; Ye, Cang

    2012-06-01

    This paper presents a pose estimation method based on the 1-Point RANSAC EKF (Extended Kalman Filter) framework. The method fuses the depth data from a LIDAR and the visual data from a monocular camera to estimate the pose of a Unmanned Ground Vehicle (UGV) in a GPS denied environment. Its estimation framework continuy updates the vehicle's 6D pose state and temporary estimates of the extracted visual features' 3D positions. In contrast to the conventional EKF-SLAM (Simultaneous Localization And Mapping) frameworks, the proposed method discards feature estimates from the extended state vector once they are no longer observed for several steps. As a result, the extended state vector always maintains a reasonable size that is suitable for online calculation. The fusion of laser and visual data is performed both in the feature initialization part of the EKF-SLAM process and in the motion prediction stage. A RANSAC pose calculation procedure is devised to produce pose estimate for the motion model. The proposed method has been successfully tested on the Ford campus's LIDAR-Vision dataset. The results are compared with the ground truth data of the dataset and the estimation error is ~1.9% of the path length.

  4. Pose prediction and virtual screening performance of GOLD scoring functions in a standardized test

    NASA Astrophysics Data System (ADS)

    Liebeschuetz, John W.; Cole, Jason C.; Korb, Oliver

    2012-06-01

    The performance of all four GOLD scoring functions has been evaluated for pose prediction and virtual screening under the standardized conditions of the comparative docking and scoring experiment reported in this Edition. Excellent pose prediction and good virtual screening performance was demonstrated using unmodified protein models and default parameter settings. The best performing scoring function for both pose prediction and virtual screening was demonstrated to be the recently introduced scoring function ChemPLP. We conclude that existing docking programs already perform close to optimally in the cognate pose prediction experiments currently carried out and that more stringent pose prediction tests should be used in the future. These should employ cross-docking sets. Evaluation of virtual screening performance remains problematic and much remains to be done to improve the usefulness of publically available active and decoy sets for virtual screening. Finally we suggest that, for certain target/scoring function combinations, good enrichment may sometimes be a consequence of 2D property recognition rather than a modelling of the correct 3D interactions.

  5. Combining in silico and in cerebro approaches for virtual screening and pose prediction in SAMPL4

    NASA Astrophysics Data System (ADS)

    Voet, Arnout R. D.; Kumar, Ashutosh; Berenger, Francois; Zhang, Kam Y. J.

    2014-04-01

    The SAMPL challenges provide an ideal opportunity for unbiased evaluation and comparison of different approaches used in computational drug design. During the fourth round of this SAMPL challenge, we participated in the virtual screening and binding pose prediction on inhibitors targeting the HIV-1 integrase enzyme. For virtual screening, we used well known and widely used in silico methods combined with personal in cerebro insights and experience. Regular docking only performed slightly better than random selection, but the performance was significantly improved upon incorporation of additional filters based on pharmacophore queries and electrostatic similarities. The best performance was achieved when logical selection was added. For the pose prediction, we utilized a similar consensus approach that amalgamated the results of the Glide-XP docking with structural knowledge and rescoring. The pose prediction results revealed that docking displayed reasonable performance in predicting the binding poses. However, prediction performance can be improved utilizing scientific experience and rescoring approaches. In both the virtual screening and pose prediction challenges, the top performance was achieved by our approaches. Here we describe the methods and strategies used in our approaches and discuss the rationale of their performances.

  6. Exploring the potential of protein-based pharmacophore models in ligand pose prediction and ranking

    PubMed Central

    Hu, Bingjie; Lill, Markus A.

    2013-01-01

    Protein-based pharmacophore models derived from the protein binding site atoms without the inclusion of any ligand information have become more popular in virtual screening studies. However, the accuracy of protein-based pharmacophore models for reproducing the critical protein-ligand interactions has never been explicitly assessed. In this study, we used known protein-ligand contacts from a large set of experimentally determined protein-ligand complexes to assess the quality of the protein-based pharmacophores in reproducing these critical contacts. We demonstrate how these contacts can be used to optimize the pharmacophore generation procedure to produce pharmacophore models that optimally cover the known protein-ligand interactions. Finally, we explored the potential of the optimized protein-based pharmacophore models for pose prediction and pose rankings. Our results demonstrate that there are significant variations in the success of protein-based pharmacophore models to reproduce native contacts and consequently native ligand poses dependent on the details of the pharmacophore-generation process. We show that the generation of optimized protein-based pharmacophore models is a promising approach for ligand pose prediction and pose rankings. PMID:23621564

  7. Single leg balancing in ballet: effects of shoe conditions and poses.

    PubMed

    Lobo da Costa, Paula H; Azevedo Nora, Fernanda G S; Vieira, Marcus Fraga; Bosch, Kerstin; Rosenbaum, Dieter

    2013-03-01

    The purpose of this study was to describe the effects of lower limb positioning and shoe conditions on stability levels of selected single leg ballet poses performed in demi-pointe position. Fourteen female non-professional ballet dancers (mean age of 18.4±2.8 years and mean body mass index of 21.5±2.8kg/m(2)) who had practiced ballet for at least seven years, without any musculoskeletal impairment volunteered to participate in this study. A capacitive pressure platform allowed for the assessment of center of pressure variables related to the execution of three single leg ballet poses in demi pointé position: attitude devant, attitude derriére, and attitude a la second. Peak pressures, contact areas, COP oscillation areas, anterior-posterior and medio-lateral COP oscillations and velocities were compared between two shoe conditions (barefoot versus slippers) and among the different poses. Barefoot performances produced more stable poses with significantly higher plantar contact areas, smaller COP oscillation areas and smaller anterior-posterior COP oscillations. COP oscillation areas, anterior-posterior COP oscillations and medio-lateral COP velocities indicated that attitude a la second is the least challenging and attitude derriére the most challenging pose.

  8. Variations in Both-Addends-Unknown Problems

    ERIC Educational Resources Information Center

    Champagne, Zachary M.; Schoen, Robert; Riddell, Claire M.

    2014-01-01

    Early elementary school students are expected to solve twelve distinct types of word problems. A math researcher and two teachers pose a structure for thinking about one problem type that has not been studied as closely as the other eleven. In this article, the authors share some of their discoveries with regard to the variety of…

  9. Boundary Value Problems With Integral Conditions

    NASA Astrophysics Data System (ADS)

    Karandzhulov, L. I.; Sirakova, N. D.

    2011-12-01

    The weakly perturbed nonlinear boundary value problems (BVP) for almost linear systems of ordinary differential equations (ODE) are considered. We assume that the nonlinear part contain an additional function, which defines the perturbation as singular. Then the Poincare method is not applicable. The problem of existence, uniqueness and construction of a solution of the posed BVP with integral condition is studied.

  10. Methods for intraoperative, sterile pose-setting of patient-specific microstereotactic frames

    NASA Astrophysics Data System (ADS)

    Vollmann, Benjamin; Müller, Samuel; Kundrat, Dennis; Ortmaier, Tobias; Kahrs, Lüder A.

    2015-03-01

    This work proposes new methods for a microstereotactic frame based on bone cement fixation. Microstereotactic frames are under investigation for minimal invasive temporal bone surgery, e.g. cochlear implantation, or for deep brain stimulation, where products are already on the market. The correct pose of the microstereotactic frame is either adjusted outside or inside the operating room and the frame is used for e.g. drill or electrode guidance. We present a patientspecific, disposable frame that allows intraoperative, sterile pose-setting. Key idea of our approach is bone cement between two plates that cures while the plates are positioned with a mechatronics system in the desired pose. This paper includes new designs of microstereotactic frames, a system for alignment and first measurements to analyze accuracy and applicable load.

  11. Accurate three-dimensional pose recognition from monocular images using template matched filtering

    NASA Astrophysics Data System (ADS)

    Picos, Kenia; Diaz-Ramirez, Victor H.; Kober, Vitaly; Montemayor, Antonio S.; Pantrigo, Juan J.

    2016-06-01

    An accurate algorithm for three-dimensional (3-D) pose recognition of a rigid object is presented. The algorithm is based on adaptive template matched filtering and local search optimization. When a scene image is captured, a bank of correlation filters is constructed to find the best correspondence between the current view of the target in the scene and a target image synthesized by means of computer graphics. The synthetic image is created using a known 3-D model of the target and an iterative procedure based on local search. Computer simulation results obtained with the proposed algorithm in synthetic and real-life scenes are presented and discussed in terms of accuracy of pose recognition in the presence of noise, cluttered background, and occlusion. Experimental results show that our proposal presents high accuracy for 3-D pose estimation using monocular images.

  12. Feature and Pose Constrained Visual Aided Inertial Navigation for Computationally Constrained Aerial Vehicles

    NASA Technical Reports Server (NTRS)

    Williams, Brian; Hudson, Nicolas; Tweddle, Brent; Brockers, Roland; Matthies, Larry

    2011-01-01

    A Feature and Pose Constrained Extended Kalman Filter (FPC-EKF) is developed for highly dynamic computationally constrained micro aerial vehicles. Vehicle localization is achieved using only a low performance inertial measurement unit and a single camera. The FPC-EKF framework augments the vehicle's state with both previous vehicle poses and critical environmental features, including vertical edges. This filter framework efficiently incorporates measurements from hundreds of opportunistic visual features to constrain the motion estimate, while allowing navigating and sustained tracking with respect to a few persistent features. In addition, vertical features in the environment are opportunistically used to provide global attitude references. Accurate pose estimation is demonstrated on a sequence including fast traversing, where visual features enter and exit the field-of-view quickly, as well as hover and ingress maneuvers where drift free navigation is achieved with respect to the environment.

  13. Texture mapping 3D models of indoor environments with noisy camera poses

    NASA Astrophysics Data System (ADS)

    Cheng, Peter; Anderson, Michael; He, Stewart; Zakhor, Avideh

    2013-03-01

    Automated 3D modeling of building interiors is used in applications such as virtual reality and environment mapping. Texturing these models allows for photo-realistic visualizations of the data collected by such modeling systems. While data acquisition times for mobile mapping systems are considerably shorter than for static ones, their recovered camera poses often suffer from inaccuracies, resulting in visible discontinuities when successive images are projected onto a surface for texturing. We present a method for texture mapping models of indoor environments that starts by selecting images whose camera poses are well-aligned in two dimensions. We then align images to geometry as well as to each other, producing visually consistent textures even in the presence of inaccurate surface geometry and noisy camera poses. Images are then composited into a final texture mosaic and projected onto surface geometry for visualization. The effectiveness of the proposed method is demonstrated on a number of different indoor environments.

  14. Pose Estimation of Unmanned Aerial Vehicles Based on a Vision-Aided Multi-Sensor Fusion

    NASA Astrophysics Data System (ADS)

    Abdi, G.; Samadzadegan, F.; Kurz, F.

    2016-06-01

    GNSS/IMU navigation systems offer low-cost and robust solution to navigate UAVs. Since redundant measurements greatly improve the reliability of navigation systems, extensive researches have been made to enhance the efficiency and robustness of GNSS/IMU by additional sensors. This paper presents a method for integrating reference data, images taken from UAVs, barometric height data and GNSS/IMU data to estimate accurate and reliable pose parameters of UAVs. We provide improved pose estimations by integrating multi-sensor observations in an EKF algorithm with IMU motion model. The implemented methodology has demonstrated to be very efficient and reliable for automatic pose estimation. The calculated position and attitude of the UAV especially when we removed the GNSS from the working cycle clearly indicate the ability of the purposed methodology.

  15. STS-47 crew poses for portrait after having been named to the SLJ mission

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-47 crewmembers pose for portrait after having been named to the Spacelab Japan (SLJ) mission scheduled for flight aboard Endeavour, Orbiter Vehicle (OV) 105. NASA and the National Space Development Agency of Japan (NASDA) recently named the four to the mission. Posing in front of the flags of the United States (U.S.) and Japan are (left to right) Mission Specialist (MS) Mae C. Jemison, Japanese NASDA Payload Specialist Mamoru Mohri, MS N. Jan Davis, and MS and Payload Commander (PLC) Mark C. Lee.

  16. Real-Time Biologically Inspired Action Recognition from Key Poses Using a Neuromorphic Architecture

    PubMed Central

    Layher, Georg; Brosch, Tobias; Neumann, Heiko

    2017-01-01

    Intelligent agents, such as robots, have to serve a multitude of autonomous functions. Examples are, e.g., collision avoidance, navigation and route planning, active sensing of its environment, or the interaction and non-verbal communication with people in the extended reach space. Here, we focus on the recognition of the action of a human agent based on a biologically inspired visual architecture of analyzing articulated movements. The proposed processing architecture builds upon coarsely segregated streams of sensory processing along different pathways which separately process form and motion information (Layher et al., 2014). Action recognition is performed in an event-based scheme by identifying representations of characteristic pose configurations (key poses) in an image sequence. In line with perceptual studies, key poses are selected unsupervised utilizing a feature-driven criterion which combines extrema in the motion energy with the horizontal and the vertical extendedness of a body shape. Per class representations of key pose frames are learned using a deep convolutional neural network consisting of 15 convolutional layers. The network is trained using the energy-efficient deep neuromorphic networks (Eedn) framework (Esser et al., 2016), which realizes the mapping of the trained synaptic weights onto the IBM Neurosynaptic System platform (Merolla et al., 2014). After the mapping, the trained network achieves real-time capabilities for processing input streams and classify input images at about 1,000 frames per second while the computational stages only consume about 70 mW of energy (without spike transduction). Particularly regarding mobile robotic systems, a low energy profile might be crucial in a variety of application scenarios. Cross-validation results are reported for two different datasets and compared to state-of-the-art action recognition approaches. The results demonstrate, that (I) the presented approach is on par with other key pose based

  17. Balance Problems

    MedlinePlus

    ... often, it could be a sign of a balance problem. Balance problems can make you feel unsteady or as ... fall-related injuries, such as hip fracture. Some balance problems are due to problems in the inner ...

  18. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS Warning Statements § 740.18 Coal tar hair dyes... coal tar hair dye containing any ingredient listed in paragraph (b) of this section shall bear,...

  19. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Coal tar hair dyes posing a risk of cancer. 740.18... (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS Warning Statements § 740.18 Coal tar hair dyes... coal tar hair dye containing any ingredient listed in paragraph (b) of this section shall bear,...

  20. Question-Posing and Question-Responding: The Heart of "Possibility Thinking" in the Early Years

    ERIC Educational Resources Information Center

    Chappell, Kerry; Craft, Anna; Burnard, Pamela; Cremin, Teresa

    2008-01-01

    Drawing on research that sought to explore the characteristics of "Possibility Thinking" as central to creativity in young children's learning, this paper considers question-posing and question-responding as the driving features of "Possibility Thinking" (PT). This qualitative study employed micro-event analysis of peer and…

  1. STS-38 crewmembers pose on OV-104's middeck for onboard crew portrait

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-38 crewmembers pose on Atlantis', Orbiter Vehicle (OV) 104's, middeck for traditional onboard (in-space) portrait. Wearing red, yellow, and orange crew polo shirts are (right to left) Mission Specialist (MS) Robert C. Springer, Pilot Frank L. Culbertson, Commander Richard O. Covey, MS Charles D. Gemar, and MS Carl J. Meade.

  2. STS-38 crew poses in front of OV-104 at KSC's SLF during post flight activity

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-38 crewmembers, wearing red, yellow, and orange polo shirts, pose in front of Atlantis, Orbiter Vehicle (OV) 104, parked on runway 33 at Kennedy Space Center's (KSC's) Shuttle Landing Facility (SLF) during post flight activities. Left to right are Commander Richard O. Covey, Mission Specialist (MS) Robert C. Springer, MS Charles D. Gemar, Pilot Frank L. Culbertson, and MS Carl J. Meade.

  3. Callous-Unemotional Traits Are Related to Combined Deficits in Recognizing Afraid Faces and Body Poses

    ERIC Educational Resources Information Center

    Munoz, Luna C.

    2009-01-01

    Results from a study that involves letting boys aged 8-16 years label emotional faces and static body poses show that callous-unemotional traits are related to poor accuracy in the tests. The results imply that a general "fear-blindness" is associated to a lack of empathy and to violence and antisocial behavior.

  4. Pose measurement method and experiments for high-speed rolling targets in a wind tunnel.

    PubMed

    Jia, Zhenyuan; Ma, Xin; Liu, Wei; Lu, Wenbo; Li, Xiao; Chen, Ling; Wang, Zhengqu; Cui, Xiaochun

    2014-12-12

    High-precision wind tunnel simulation tests play an important role in aircraft design and manufacture. In this study, a high-speed pose vision measurement method is proposed for high-speed and rolling targets in a supersonic wind tunnel. To obtain images with high signal-to-noise ratio and avoid impacts on the aerodynamic shape of the rolling targets, a high-speed image acquisition method based on ultrathin retro-reflection markers is presented. Since markers are small-sized and some of them may be lost when the target is rolling, a novel markers layout with which markers are distributed evenly on the surface is proposed based on a spatial coding method to achieve highly accurate pose information. Additionally, a pose acquisition is carried out according to the mentioned markers layout after removing mismatching points by Case Deletion Diagnostics. Finally, experiments on measuring the pose parameters of high-speed targets in the laboratory and in a supersonic wind tunnel are conducted to verify the feasibility and effectiveness of the proposed method. Experimental results indicate that the position measurement precision is less than 0.16 mm, the pitching and yaw angle precision less than 0.132° and the roll angle precision 0.712°.

  5. Integrated contour detection and pose estimation for fluoroscopic analysis of knee implants.

    PubMed

    Prins, A H; Kaptein, B L; Stoel, B C; Nelissen, R G H H; Reiber, J H C; Valstar, E R

    2011-08-01

    With fluoroscopic analysis of knee implant kinematics the implant contour must be detected in each image frame, followed by estimation of the implant pose. With a large number of possibly low-quality images, the contour detection is a time-consuming bottleneck. The present paper proposes an automated contour detection method, which is integrated in the pose estimation. In a phantom experiment the automated method was compared with a standard method, which uses manual selection of correct contour parts. Both methods demonstrated comparable precision, with a minor difference in the Y-position (0.08 mm versus 0.06 mm). The precision of each method was so small (below 0.2 mm and 0.3 degrees) that both are sufficiently accurate for clinical research purposes. The efficiency of both methods was assessed on six clinical datasets. With the automated method the observer spent 1.5 min per image, significantly less than 3.9 min with the standard method. A Bland-Altman analysis between the methods demonstrated no discernible trends in the relative femoral poses. The threefold increase in efficiency demonstrates that a pose estimation approach with integrated contour detection is more intuitive than a standard method. It eliminates most of the manual work in fluoroscopic analysis, with sufficient precision for clinical research purposes.

  6. Relative position and pose measurement approach of specific operation site of space non-cooperative target

    NASA Astrophysics Data System (ADS)

    Chen, Feng; Zhou, Ying; Li, Ronghua; Huang, Jianming

    2015-12-01

    In order to achieve the rendezvous and capture of the space non-cooperative target, the relative position and pose measurement of non-cooperative target must be resolved. Since the marker is not installed into the non-cooperative target and there is no inter satellite link to transfer the information, so it is very difficult to measure the relative position and pose measurement of non-cooperative target. The solar array connecting frame of non-cooperative targets have their characters and are easy to capture, so the position and pose measurement of specific operation site of non-cooperative target based on stereo vision has been studied in this paper. The method composed of image acquiring, image filtering, edge detection, feature extraction and relative pose measurement. Finally, the relative position and attitude parameters of the solar wing connection were obtained and provided to the control system. The results of simulation and ground verification show that the algorithm is accurate and effective, and can satisfy the technical requirements of the on orbit operation. The measurement approach can be used for engineering implementation.

  7. Locating binding poses in protein-ligand systems using reconnaissance metadynamics

    PubMed Central

    Söderhjelm, Pär; Tribello, Gareth A.; Parrinello, Michele

    2012-01-01

    A molecular dynamics-based protocol is proposed for finding and scoring protein-ligand binding poses. This protocol uses the recently developed reconnaissance metadynamics method, which employs a self-learning algorithm to construct a bias that pushes the system away from the kinetic traps where it would otherwise remain. The exploration of phase space with this algorithm is shown to be roughly six to eight times faster than unbiased molecular dynamics and is only limited by the time taken to diffuse about the surface of the protein. We apply this method to the well-studied trypsin–benzamidine system and show that we are able to refind all the poses obtained from a reference EADock blind docking calculation. These poses can be scored based on the length of time the system remains trapped in the pose. Alternatively, one can perform dimensionality reduction on the output trajectory and obtain a map of phase space that can be used in more expensive free-energy calculations. PMID:22440749

  8. The Perception of Faces in Different Poses by One-Month-Olds.

    ERIC Educational Resources Information Center

    Sai, F.; Bushnell, I. W. R.

    The ability of 1-month-old infants to recognize their mothers visually was explored with the live faces of mother and stranger presented in three different poses: en face (full face), half-profile, and profile. Subjects were 16 infants with normal Apgar scores at birth who were volunteered by their parents after an initial contact in a maternity…

  9. 6-DOF Pose Estimation of a Robotic Navigation Aid by Tracking Visual and Geometric Features.

    PubMed

    Ye, Cang; Hong, Soonhac; Tamjidi, Amirhossein

    2015-10-01

    This paper presents a 6-DOF Pose Estimation (PE) method for a Robotic Navigation Aid (RNA) for the visually impaired. The RNA uses a single 3D camera for PE and object detection. The proposed method processes the camera's intensity and range data to estimates the camera's egomotion that is then used by an Extended Kalman Filter (EKF) as the motion model to track a set of visual features for PE. A RANSAC process is employed in the EKF to identify inliers from the visual feature correspondences between two image frames. Only the inliers are used to update the EKF's state. The EKF integrates the egomotion into the camera's pose in the world coordinate system. To retain the EKF's consistency, the distance between the camera and the floor plane (extracted from the range data) is used by the EKF as the observation of the camera's z coordinate. Experimental results demonstrate that the proposed method results in accurate pose estimates for positioning the RNA in indoor environments. Based on the PE method, a wayfinding system is developed for localization of the RNA in a home environment. The system uses the estimated pose and the floorplan to locate the RNA user in the home environment and announces the points of interest and navigational commands to the user through a speech interface.

  10. Pose Measurement Method and Experiments for High-Speed Rolling Targets in a Wind Tunnel

    PubMed Central

    Jia, Zhenyuan; Ma, Xin; Liu, Wei; Lu, Wenbo; Li, Xiao; Chen, Ling; Wang, Zhengqu; Cui, Xiaochun

    2014-01-01

    High-precision wind tunnel simulation tests play an important role in aircraft design and manufacture. In this study, a high-speed pose vision measurement method is proposed for high-speed and rolling targets in a supersonic wind tunnel. To obtain images with high signal-to-noise ratio and avoid impacts on the aerodynamic shape of the rolling targets, a high-speed image acquisition method based on ultrathin retro-reflection markers is presented. Since markers are small-sized and some of them may be lost when the target is rolling, a novel markers layout with which markers are distributed evenly on the surface is proposed based on a spatial coding method to achieve highly accurate pose information. Additionally, a pose acquisition is carried out according to the mentioned markers layout after removing mismatching points by Case Deletion Diagnostics. Finally, experiments on measuring the pose parameters of high-speed targets in the laboratory and in a supersonic wind tunnel are conducted to verify the feasibility and effectiveness of the proposed method. Experimental results indicate that the position measurement precision is less than 0.16 mm, the pitching and yaw angle precision less than 0.132° and the roll angle precision 0.712°. PMID:25615732

  11. Pose-Angular Tracking of Maneuvering Targets With High Range Resolution (HRR) Radar

    DTIC Science & Technology

    2008-07-01

    useful for tracking maneuvering targets . For target identification (ID), range profiles obtained by a high range resolution (HRR) radar are...of moving targets . Keywords: Tracking, Maneuver, Target ID, Pose, HRR. 1 Introduction Compared to conventional tracking with post- detection ...range profile is generated. HRR range profiles have long been used for target identification (ID) or fingerprinting [8, 9, 13, 15]. It has also

  12. Astronauts Mario Runco, Jr. and Andrew S. W. Thomas, both mission specialists, pose for photo while

    NASA Technical Reports Server (NTRS)

    1996-01-01

    STS-77 ESC VIEW --- Astronauts Mario Runco, Jr. and Andrew S. W. Thomas, both mission specialists, pose for photo while in the mid-deck of the Earth-orbiting Space Shuttle Endeavour. The scene was recorded with an Electronic Still Camera (ESC).

  13. Child food insecurity increases risks posed by household food insecurity to young children's health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The US Food Security Scale (USFSS) measures household and child food insecurity (CFI) separately. Our goal was to determine whether CFI increases risks posed by household food insecurity (HFI) to child health and whether the Food Stamp Program (FSP) modifies these effects. From 1998 to 2004, 17,158 ...

  14. STS-33 MS Musgrave, wearing headset, poses on Discovery's, OV-103's, middeck

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-33 Mission Specialist (MS) F. Story Musgrave, wearing comunications kit assembly headset and light blue flight coveralls, poses on Discovery's, Orbiter Vehicle (OV) 103's, middeck. Behind Musgrave on the starboard wall are the sleep restraints, a camera, and a camera mounting bracket.

  15. Robust Head-Pose Estimation Based on Partially-Latent Mixture of Linear Regressions

    NASA Astrophysics Data System (ADS)

    Drouard, Vincent; Horaud, Radu; Deleforge, Antoine; Ba, Sileye; Evangelidis, Georgios

    2017-03-01

    Head-pose estimation has many applications, such as social event analysis, human-robot and human-computer interaction, driving assistance, and so forth. Head-pose estimation is challenging because it must cope with changing illumination conditions, variabilities in face orientation and in appearance, partial occlusions of facial landmarks, as well as bounding-box-to-face alignment errors. We propose tu use a mixture of linear regressions with partially-latent output. This regression method learns to map high-dimensional feature vectors (extracted from bounding boxes of faces) onto the joint space of head-pose angles and bounding-box shifts, such that they are robustly predicted in the presence of unobservable phenomena. We describe in detail the mapping method that combines the merits of unsupervised manifold learning techniques and of mixtures of regressions. We validate our method with three publicly available datasets and we thoroughly benchmark four variants of the proposed algorithm with several state-of-the-art head-pose estimation methods.

  16. Twenty-one degrees of freedom model based hand pose tracking using a monocular RGB camera

    NASA Astrophysics Data System (ADS)

    Choi, Junyeong; Park, Jong-Il; Park, Hanhoon

    2016-01-01

    It is difficult to visually track a user's hand because of the many degrees of freedom (DOF) a hand has. For this reason, most model-based hand pose tracking methods have relied on the use of multiview images or RGB-D images. This paper proposes a model-based method that accurately tracks three-dimensional hand poses using monocular RGB images in real time. The main idea of the proposed method is to reduce hand tracking ambiguity by adopting a step-by-step estimation scheme consisting of three steps performed in consecutive order: palm pose estimation, finger yaw motion estimation, and finger pitch motion estimation. In addition, this paper proposes highly effective algorithms for each step. With the assumption that a human hand can be considered as an assemblage of articulated planes, the proposed method uses a piece-wise planar hand model which enables hand model regeneration. The hand model regeneration modifies the hand model to fit the current user's hand and improves the accuracy of the hand pose estimation results. Above all, the proposed method can operate in real time using only CPU-based processing. Consequently, it can be applied to various platforms, including egocentric vision devices such as wearable glasses. The results of several experiments conducted verify the efficiency and accuracy of the proposed method.

  17. STS-44 MS Runco and MS Voss pose with EMUs in OV-104's airlock

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-44 Mission Specialist (MS) Mario Runco, Jr (left) and MS James S. Voss pose with two extravehicular mobility units (EMUs) in Atlantis', Orbiter Vehicle (OV) 104's, airlock. The EMUs are mounted on airlock adapter plates (AAPs) and have lower torso restraints in place. They are stowed in the airlock and will be used in the event of a contingency extravehicular activity (EVA).

  18. STS-26 Commander Hauck poses on shuttle mockup aft flight deck

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Commander Frederick H. Hauck poses on shuttle mockup aft flight deck in the Shuttle Mockup and Integration Laboratory Bldg 9A. Hauck's right hand is propped on Onorbit Station control panel A2 remote manipulator system (RMS) translation hand control. Photograph was taken by Keith Meyers of the NEW YORK TIMES.

  19. An evaluation of 3D head pose estimation using the Microsoft Kinect v2.

    PubMed

    Darby, John; Sánchez, María B; Butler, Penelope B; Loram, Ian D

    2016-07-01

    The Kinect v2 sensor supports real-time non-invasive 3D head pose estimation. Because the sensor is small, widely available and relatively cheap it has great potential as a tool for groups interested in measuring head posture. In this paper we compare the Kinect's head pose estimates with a marker-based record of ground truth in order to establish its accuracy. During movement of the head and neck alone (with static torso), we find average errors in absolute yaw, pitch and roll angles of 2.0±1.2°, 7.3±3.2° and 2.6±0.7°, and in rotations relative to the rest pose of 1.4±0.5°, 2.1±0.4° and 2.0±0.8°. Larger head rotations where it becomes difficult to see facial features can cause estimation to fail (10.2±6.1% of all poses in our static torso range of motion tests) but we found no significant changes in performance with the participant standing further away from Kinect - additionally enabling full-body pose estimation - or without performing face shape calibration, something which is not always possible for younger or disabled participants. Where facial features remain visible, the sensor has applications in the non-invasive assessment of postural control, e.g. during a programme of physical therapy. In particular, a multi-Kinect setup covering the full range of head (and body) movement would appear to be a promising way forward.

  20. A well-posed and stable stochastic Galerkin formulation of the incompressible Navier–Stokes equations with random data

    SciTech Connect

    Pettersson, Per; Nordström, Jan; Doostan, Alireza

    2016-02-01

    We present a well-posed stochastic Galerkin formulation of the incompressible Navier–Stokes equations with uncertainty in model parameters or the initial and boundary conditions. The stochastic Galerkin method involves representation of the solution through generalized polynomial chaos expansion and projection of the governing equations onto stochastic basis functions, resulting in an extended system of equations. A relatively low-order generalized polynomial chaos expansion is sufficient to capture the stochastic solution for the problem considered. We derive boundary conditions for the continuous form of the stochastic Galerkin formulation of the velocity and pressure equations. The resulting problem formulation leads to an energy estimate for the divergence. With suitable boundary data on the pressure and velocity, the energy estimate implies zero divergence of the velocity field. Based on the analysis of the continuous equations, we present a semi-discretized system where the spatial derivatives are approximated using finite difference operators with a summation-by-parts property. With a suitable choice of dissipative boundary conditions imposed weakly through penalty terms, the semi-discrete scheme is shown to be stable. Numerical experiments in the laminar flow regime corroborate the theoretical results and we obtain high-order accurate results for the solution variables and the velocity divergence converges to zero as the mesh is refined.

  1. Sex differences over age groups in self-posed smiling in photographs.

    PubMed

    Otta, E

    1998-12-01

    The present study was designed to investigate self-posed smiling behavior in photographs as a function of both sex and age. The photographs of 1,171 Brazilian middle-class people, taken in a wide variety of informal social settings were examined. Only 25.7% of the girls and 25.0% of the boys of 2- to 5-yrs-age group were seen smiling in the photographs. Older children, adolescents, and adults were much more expressive than young children. Furthermore, significantly more females were seen smiling than males. Females also smiled more expansively than males. Finally, smiling was less frequent among middle-aged and older groups, especially among males. The present study replicated the sex difference in self-posed smiling behavior consistently reported by American researchers examining college yearbook photographs. Further, the results are consistent with the hypothesis that, besides being associated with emotional experience, smiling has a strong social motivation.

  2. Pose measurement of Anterior Pelvic Plane based on inertial measurement unit in total hip replacement surgeries.

    PubMed

    Zhe Cao; Shaojie Su; Hong Chen; Hao Tang; Yixin Zhou; Zhihua Wang

    2016-08-01

    In Total Hip Replacement (THR), inaccurate measurement of Anterior Pelvic Plane (APP), which is usually used as a reference plane, will lead to malposition of the acetabular prosthesis. As a result, the risk of impingement, dislocation and wear will increase and the safe range of motion will be limited. In order to acquire the accurate pose of APP, a measurement system is designed in this paper, which includes two parts: one is used to estimate the initial pose of APP and the other is used to trail dynamic motion of APP. Both parts are composed of an Inertial Measurement Unit (IMU) and magnetometer sensors. An Extended Kalman Filter (EKF) is adopted to fuse the data from IMU and the magnetometer sensors to estimate the orientation of the pelvis. The test results show that the error angle between calculated axis and true axis of the pelvis in geodetic coordinate frame is less than 1.2 degree, which meets the requirement of the surgery.

  3. Statistical analysis of relative pose information of subcortical nuclei: Application on ADNI data

    PubMed Central

    Bossa, Matias; Zacur, Ernesto; Olmos, Salvador

    2012-01-01

    Many brain morphometry studies have been performed in order to characterize the brain atrophy pattern of Alzheimer’s disease (AD). The earliest studies focused on the volume of particular brain structures, such as hippocampus and entorhinal cortex. Even though volumetry is a powerful, robust and intuitive technique that has yielded a wealth of findings, more complex shape descriptors have been used to perform statistical shape analysis of particular brain structures. However, in shape analysis studies of brain structures the information of the relative pose between neighbor structures is typically disregarded. This work presents a framework to analyse pose information including the following approaches: similarity transformations with either pseudo-Riemannian or left-invariant Riemannian metric, and centered transformations with a bi-invariant Riemannian metric. As an illustration, an analysis of covariance (ANCOVA) and a discrimination analysis were performed on Alzheimer’s Disease Neuroimaging Initiative (ADNI) data. PMID:21216295

  4. Theory research of seam recognition and welding torch pose control based on machine vision

    NASA Astrophysics Data System (ADS)

    Long, Qiang; Zhai, Peng; Liu, Miao; He, Kai; Wang, Chunyang

    2017-03-01

    At present, the automation requirement of the welding become higher, so a method of the welding information extraction by vision sensor is proposed in this paper, and the simulation with the MATLAB has been conducted. Besides, in order to improve the quality of robot automatic welding, an information retrieval method for welding torch pose control by visual sensor is attempted. Considering the demands of welding technology and engineering habits, the relative coordinate systems and variables are strictly defined, and established the mathematical model of the welding pose, and verified its feasibility by using the MATLAB simulation in the paper, these works lay a foundation for the development of welding off-line programming system with high precision and quality.

  5. Model-based Object Localization and Pose Estimation Method Robust Against the Stereo Miscorrespondence

    NASA Astrophysics Data System (ADS)

    Watanabe, Masaharu; Tomita, Fumiaki; Maruyama, Kenichi; Kawai, Yoshihiro; Fujimura, Kouta

    The miscorrespondence in stereo image analysis, which is caused by occlusion among images with failure in edge detection, often occurs in real factory environment, and this seriously disturbs the object localization and pose estimation. This work shows that, even under such conditions, the location and attitude of target object can precisely be measured, based on the three base-line trinocular stereo image analysis, using a “model-based verification” method, i.e., a model-based object recognition method including a multi-modal optimization algorithm. This method is suitable for real applications which need object localization and pose estimation, like a bin picking of parts randomly placed on factory automation.

  6. Combining structured light and ladar for pose tracking in THz sensor management

    NASA Astrophysics Data System (ADS)

    Engström, Philip; Axelsson, Maria; Karlsson, Mikael

    2013-05-01

    Stand-off 3D THz imaging to detect concealed treats is currently under development. The technology can provide high resolution 3D range data of a passing subject showing layers of clothes and if there are concealed items. However, because it is a scanning sensor technology with a narrow field of view, the subjects pose and position need to be accurately tracked in real time to focus the system and map the imaged THz data to specific body parts. Structured light is a technique to obtain 3D range information. It is, for example, used in the Microsoft Kinect for pose tracking of game players in real time. We demonstrate how structured light can contribute to a THz sensor management system and track subjects in real time. The main advantage of structured light is its simplicity, the disadvantages are the sensitivity to lighting conditions and material properties as well as a relatively low accuracy. Time of flight laser scanning is a technique that complements structured light well, the accuracy is usually much higher and it is less sensitive to lighting conditions. We show that by combining the techniques it is possible to create a robust real time pose tracking system for THz sensor management. We present a concept system based on the Microsoft Kinect and a SICK LMS-511 laser scanner. The laser scanner is used for 2D tracking of the subjects, this tracking is then used to initialize and validate the Microsoft Kinect pose tracking. We have evaluated the sensors individually in both static and dynamic scenes and present their advantages and drawbacks.

  7. STS-30 crewmembers pose for onboard portrait on OV-104's middeck

    NASA Technical Reports Server (NTRS)

    1989-01-01

    During STS-30 aboard Atlantis, Orbiter Vehicle (OV) 104, crewmembers pose for portrait. In front of middeck starboard wall-mounted sleep restraints, are (clockwise from top right) Commander David M. Walker, Mission Specialist (MS) Mary L. Cleave, MS Mark C. Lee, MS Norman E. Thagard, and Pilot Ronald J. Grabe. Crewmembers are wearing red, white, and blue mission polo shirts and light blue flight coveralls.

  8. STS-44 crew poses for their onboard (in-space) portrait on OV-104's middeck

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-44 crewmembers, wearing mission polo shirts, pose for their onboard (in-space) portrait on the middeck of Atlantis, Orbiter Vehicle (OV) 104. In the center with his arms outsearched is Commander Frederick D. Gregory. Clockwise from his position are Payload Specialist Thomas J. Hennen (mustache), Mission Specialist (MS) James S. Voss, MS Mario Runco, Jr, MS F. Story Musgrave, and Pilot Terence T. Henricks.

  9. STS-33 crewmember pose on Discovery, OV-103, middeck for onboard portrait

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-33 crewmembers, wearing mission polo shirts, pose on the middeck of Discovery, Orbiter Vehicle (OV) 103, for onboard (in-space) crew portrait. Clockwise (starting at the top of the frame) are Commander Frederick D. Gregory, Mission Specialist (MS) Kathryn C. Thornton, Pilot John E. Blaha, MS Manley L. Carter, Jr, and MS F. Story Musgrave. Framing the crew are the airlock hatch (at the bottom) and the forward lockers (at the top).

  10. Real-Time Head Pose Estimation Using a WEBCAM: Monocular Adaptive View-Based Appearance Model

    DTIC Science & Technology

    2008-12-01

    Huang (2006). Graph embedded analysis for head pose estimation. In Proc. IEEE Intl. Conf. Automatic Face and Gesture Recognition , pp. 3–8. Fu, Y. and T...of human- computer and human-robot interaction. Possible appli- cations include novel computer input devices (Fu and Huang, 2007), head gesture ... recognition , driver fatigue recognition systems (Baker et al., 2004), attention aware- ness for intelligent tutoring systems, and social interac- tion

  11. Expedition-8 Flight Members Pose Inside the Soyuz TMA-3 Vehicle

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Posed inside the Soyuz TMA-3 Vehicle in a processing facility at the Baikonur Cosmodrome in Kazakhstan during a pre-launch inspection are (left to right): Expedition-8 Crew members, Michael C. Foale, Mission Commander and NASA ISS Science Officer; Cosmonaut Alexander Y. Kaleri, Soyuz Commander and flight engineer; and European Space Agency (ESA) astronaut Pedro Duque of Spain. The three launched from the Cosmodrome on October 18, 2003 onboard a Soyuz rocket destined for the International Space Station (ISS).

  12. Dr. David Brown poses with a portrait of Ronald McNair

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In the gymnasium of Ronald McNair Magnet School in Cocoa, Fla., Dr. David Brown, a NASA astronaut, poses with a portrait of NASA astronaut Ronald McNair. The portrait was presented to the school by Walt Disney World during a tribute to McNair. The school had previously been renamed for the fallen astronaut who was one of a crew of seven who lost their lives during an accident following launch of the Space Shuttle Challenger in January 1986.

  13. Mickey Mouse poses with a portrait of Ronald McNair

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In the gymnasium of Ronald McNair Magnet School in Cocoa, Fla., Mickey Mouse poses with a portrait of NASA astronaut Ronald McNair. The portrait was presented to the school by Walt Disney World during a tribute to McNair. The school had previously been renamed for the fallen astronaut who was one of a crew of seven who lost their lives during an accident following launch of the Space Shuttle Challenger in January 1986.

  14. On Landweber-Kaczmarz methods for regularizing systems of ill-posed equations in Banach spaces

    NASA Astrophysics Data System (ADS)

    Leitão, A.; Marques Alves, M.

    2012-10-01

    In this paper, iterative regularization methods of Landweber-Kaczmarz type are considered for solving systems of ill-posed equations modeled (finitely many) by operators acting between Banach spaces. Using assumptions of uniform convexity and smoothness on the parameter space, we are able to prove a monotony result for the proposed method, as well as to establish convergence (for exact data) and stability results (in the noisy data case).

  15. STS-41 crew poses in front of OV-103 on concrete runway 22 at EAFB, Calif

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-41 crewmembers pose in front of Discovery, Orbiter Vehicle (OV) 103, parked on concrete runway 22 at Edwards Air Force Base (EAFB), California. Having just completed their mission, the crewmembers are still wearing their launch and entry suits (LESs). From left to right are Mission Specialist (MS) Thomas D. Akers, Pilot Robert D. Cabana, Commander Richard N. Richards, MS Bruce E. Melnick, and MS William M. Shepherd.

  16. Performance Evaluation of a Pose Estimation Method based on the SwissRanger SR4000

    DTIC Science & Technology

    2012-08-01

    however, not suitable for navigating a small robot. Commercially available Flash LIDAR now has sufficient accuracy for robotic application . A...499978-1-4673-1278-3/12/$31.00 ©2012 IEEE Proceedings of 2012 IEEE International Conference on Mechatronics and Automation August 5 - 8, Chengdu, China... theory , the pose change between two image frames can be computed from three matched data points. This scheme only works well with noise-free range

  17. Investigation of the Hazards Posed by Chemical Vapors Released in Marine Operations - Phase II.

    DTIC Science & Technology

    1983-04-01

    at San Antonio, Texas . 307 U.S. COAST GUARDf SOUTHWEST RESEARCH INSTITUTE, SAN ANTONIO, TEXAS , USA UNIVERSITY OF TEXAS SCHOOL OF PUBLIC HEALTH, HOUSTON... TEXAS , USA SUBJECT CONSENT FOR PARTICIPATION IN AN INVESTIGATION OF "HAZARDS POSED BY CHEMICAL VAPORS RELEASED IN MARINE OPERATIONS: TASK V...write to the following persons: Dr. Stanley M. Pier Mr. William J. Astleford 5326 Dora Street Southwest Research Institute Houston, Texas , 77005, USA

  18. STS-26 crew poses for group portrait on shuttle mockup middeck in Bldg 9A

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers pose on shuttle mockup middeck (port side) in the Shuttle Mockup and Integration Laboratory Bldg 9A. Clockwise from left foreground are Commander Frederick H. Hauck, Mission Specialist (MS) George D. Nelson, Pilot Richard O. Covey, MS John M. Lounge, and MS David C. Hilmers. Crewmembers are wearing flight coveralls (jump suits). Nelson stands on middeck ladder and Lounge sits in open side hatch. Photograph was taken by Keith Meyers of the NEW YORK TIMES.

  19. Balance Problems

    MedlinePlus

    ... version of this page please turn Javascript on. Balance Problems About Balance Problems Have you ever felt dizzy, lightheaded, or ... dizziness problem during the past year. Why Good Balance is Important Having good balance means being able ...

  20. Pose Self-Calibration of Stereo Vision Systems for Autonomous Vehicle Applications

    PubMed Central

    Musleh, Basam; Martín, David; Armingol, José María; de la Escalera, Arturo

    2016-01-01

    Nowadays, intelligent systems applied to vehicles have grown very rapidly; their goal is not only the improvement of safety, but also making autonomous driving possible. Many of these intelligent systems are based on making use of computer vision in order to know the environment and act accordingly. It is of great importance to be able to estimate the pose of the vision system because the measurement matching between the perception system (pixels) and the vehicle environment (meters) depends on the relative position between the perception system and the environment. A new method of camera pose estimation for stereo systems is presented in this paper, whose main contribution regarding the state of the art on the subject is the estimation of the pitch angle without being affected by the roll angle. The validation of the self-calibration method is accomplished by comparing it with relevant methods of camera pose estimation, where a synthetic sequence is used in order to measure the continuous error with a ground truth. This validation is enriched by the experimental results of the method in real traffic environments. PMID:27649178

  1. Joint Head Pose/Soft Label Estimation for Human Recognition In-The-Wild.

    PubMed

    Proenca, Hugo; Neves, Joao C; Barra, Silvio; Marques, Tiago; Moreno, Juan C

    2016-12-01

    Soft biometrics have been emerging to complement other traits and are particularly useful for poor quality data. In this paper, we propose an efficient algorithm to estimate human head poses and to infer soft biometric labels based on the 3D morphology of the human head. Starting by considering a set of pose hypotheses, we use a learning set of head shapes synthesized from anthropometric surveys to derive a set of 3D head centroids that constitutes a metric space. Next, representing queries by sets of 2D head landmarks, we use projective geometry techniques to rank efficiently the joint 3D head centroids/pose hypotheses according to their likelihood of matching each query. The rationale is that the most likely hypotheses are sufficiently close to the query, so a good solution can be found by convex energy minimization techniques. Once a solution has been found, the 3D head centroid and the query are assumed to have similar morphology, yielding the soft label. Our experiments point toward the usefulness of the proposed solution, which can improve the effectiveness of face recognizers and can also be used as a privacy-preserving solution for biometric recognition in public environments.

  2. Joint Head Pose / Soft Label Estimation for Human Recognition In-The-Wild.

    PubMed

    Proenca, Hugo; Neves, Joao; Marques, Tiago; Barra, Silvio; Moreno, Juan

    2016-01-27

    Soft biometrics have been emerging to complement other traits and are particularly useful for poor quality data. In this paper, we propose an efficient algorithm to estimate human head poses and to infer soft biometric labels based on the 3D morphology of the human head. Starting by considering a set of pose hypotheses, we use a learning set of head shapes synthesized from anthropometric surveys to derive a set of 3D head centroids that constitutes a metric space. Next, representing queries by sets of 2D head landmarks, we use projective geometry techniques to rank efficiently the joint 3D head centroids / pose hypotheses according to their likelihood of matching each query. The rationale is that the most likely hypotheses are sufficiently close to the query, so a good solution can be found by convex energy minimization techniques. Once a solution has been found, the 3D head centroid and the query are assumed to have similar morphology, yielding the soft label. Our experiments point toward the usefulness of the proposed solution, which can improve the effectiveness of face recognizers and can also be used as a privacy-preserving solution for biometric recognition in public environments.

  3. Explanation, motivation and question posing routines in university mathematics teachers' pedagogical discourse: a commognitive analysis

    NASA Astrophysics Data System (ADS)

    Viirman, Olov

    2015-11-01

    This paper investigates the teaching practices used by university mathematics teachers when lecturing, a topic within university mathematics education research which is gaining an increasing interest. In the study, a view of mathematics teaching as a discursive practice is taken, and Sfard's commognitive framework is used to investigate the teaching practices of seven Swedish university mathematics teachers on the topic of functions. The present paper looks at the discourse of mathematics teaching, presenting a categorization of the didactical routines into three categories - explanation, motivation and question posing routines. All of these are present in the discourses of all seven teachers, but within these general categories, a number of different sub-categories of routines are found, used in different ways and to different extent by the various teachers. The explanation routines include known mathematical facts, summary and repetition, different representations, everyday language, and concretization and metaphor; the motivation routines include reference to utility, the nature of mathematics, humour and result focus; and the question posing routines include control questions, asking for facts, enquiries and rhetorical questions. This categorization of question posing routines, for instance, complements those already found in the literature. In addition to providing a valuable insight into the teaching of functions at the university level, the categorizations presented in the study can also be useful for investigating the teaching of other mathematical topics.

  4. Pose control of the chain composed of magnetic particles using external uniform and gradient magnetic fields

    NASA Astrophysics Data System (ADS)

    Zhou, J. F.; Shao, C. L.; Gu, B. Q.

    2016-01-01

    Magnetic particles (MPs) are known to respond to a magnetic field and can be moved by magnetic force, which make them good carriers in bioengineering and pharmaceutical engineering. In this paper, a pose control method for the straight chain composed of MPs is proposed, and the chain with one pose can be moved to another position with another pose using alternately employed uniform and gradient magnetic fields. Based on computer simulations, it is revealed that in the uniform magnetic field, the MPs form a straight chain with the same separation space along the field lines, and once the uniform magnetic field rotates, the chain also rotates with the field. In the gradient magnetic field, the MPs move toward the higher field so that the translation of the chain can be realized. The simulation results indicate that while the uniform magnetic field is rotating, there exists certain hysteresis between the chain and the field, and the chain is not straight anymore. So the uniform magnetic field should rest at the target angle for a period to make the chain fully relax to be straight. For nanoMP, its magnetic moment directly determines the gradient magnetic force which is much smaller than the dipole-dipole force among MPs. Therefore, the translation of the chain is much more time-consuming than rotation. To enlarge the translational velocity, it is suggested to increase the size of MPs or the magnetic field gradient.

  5. Pose Performance of LIDAR-Based Relative Navigation for Non-Cooperative Objects

    NASA Astrophysics Data System (ADS)

    Sell, Jordan L.

    Flash LIDAR is an important new sensing technology for relative navigation; these sensors have shown promising results during rendezvous and docking applications involving a cooperative vehicle. An area of recent interest is the application of this technology for pose estimation with non-cooperative client vehicles, in support of on-orbit satellite servicing activities and asteroid redirect missions. The capability for autonomous rendezvous with non-cooperative satellites will enable refueling and servicing of satellites (particularly those designed without servicing in mind), allowing these vehicles to continue operating rather than being retired. Rendezvous with an asteroid will give further insight to the origin of individual asteroids. This research investigates numerous issues surrounding pose performance using LIDAR. To begin analyzing the characteristics of the data produced by Flash LIDAR, simulated and laboratory testing have been completed. Observations of common asteroid materials were made with a surrogate LIDAR, characterizing the reflectivity of the materials. A custom Iterative Closest Point (ICP) algorithm was created to estimate the relative position and orientation of the LIDAR relative to the observed object. The performance of standardized pose estimation techniques (including ICP) has been examined using non-cooperative data as well as the characteristics of the materials that will potentially be observed during missions. For the hardware tests, a SwissRanger ToF camera was used as a surrogate Flash LIDAR.

  6. A combined vision-inertial fusion approach for 6-DoF object pose estimation

    NASA Astrophysics Data System (ADS)

    Li, Juan; Bernardos, Ana M.; Tarrío, Paula; Casar, José R.

    2015-02-01

    The estimation of the 3D position and orientation of moving objects (`pose' estimation) is a critical process for many applications in robotics, computer vision or mobile services. Although major research efforts have been carried out to design accurate, fast and robust indoor pose estimation systems, it remains as an open challenge to provide a low-cost, easy to deploy and reliable solution. Addressing this issue, this paper describes a hybrid approach for 6 degrees of freedom (6-DoF) pose estimation that fuses acceleration data and stereo vision to overcome the respective weaknesses of single technology approaches. The system relies on COTS technologies (standard webcams, accelerometers) and printable colored markers. It uses a set of infrastructure cameras, located to have the object to be tracked visible most of the operation time; the target object has to include an embedded accelerometer and be tagged with a fiducial marker. This simple marker has been designed for easy detection and segmentation and it may be adapted to different service scenarios (in shape and colors). Experimental results show that the proposed system provides high accuracy, while satisfactorily dealing with the real-time constraints.

  7. Personal privacy, information assurance, and the threat posed by malware techology

    NASA Astrophysics Data System (ADS)

    Stytz, Martin R.; Banks, Sheila B.

    2006-04-01

    In spite of our best efforts to secure the cyber world, the threats posed to personal privacy by attacks upon networks and software continue unabated. While there are many reasons for this state of affairs, clearly one of the reasons for continued vulnerabilities in software is the inability to assess their security properties and test their security systems while they are in development. A second reason for this growing threat to personal privacy is the growing sophistication and maliciousness of malware coupled with the increasing difficulty of detecting malware. The pervasive threat posed by malware coupled with the difficulties faced when trying to detect its presence or an attempted intrusion make addressing the malware threat one of the most pressing issues that must be solved in order to insure personal privacy to users of the internet. In this paper, we will discuss the threat posed by malware, the types of malware found in the wild (outside of computer laboratories), and current techniques that are available for from a successful malware penetration. The paper includes a discussion of anti-malware tools and suggestions for future anti-malware efforts.

  8. Pose Self-Calibration of Stereo Vision Systems for Autonomous Vehicle Applications.

    PubMed

    Musleh, Basam; Martín, David; Armingol, José María; de la Escalera, Arturo

    2016-09-14

    Nowadays, intelligent systems applied to vehicles have grown very rapidly; their goal is not only the improvement of safety, but also making autonomous driving possible. Many of these intelligent systems are based on making use of computer vision in order to know the environment and act accordingly. It is of great importance to be able to estimate the pose of the vision system because the measurement matching between the perception system (pixels) and the vehicle environment (meters) depends on the relative position between the perception system and the environment. A new method of camera pose estimation for stereo systems is presented in this paper, whose main contribution regarding the state of the art on the subject is the estimation of the pitch angle without being affected by the roll angle. The validation of the self-calibration method is accomplished by comparing it with relevant methods of camera pose estimation, where a synthetic sequence is used in order to measure the continuous error with a ground truth. This validation is enriched by the experimental results of the method in real traffic environments.

  9. ULTOR(Registered TradeMark) Passive Pose and Position Engine For Spacecraft Relative Navigation

    NASA Technical Reports Server (NTRS)

    Hannah, S. Joel

    2008-01-01

    The ULTOR(Registered TradeMark) Passive Pose and Position Engine (P3E) technology, developed by Advanced Optical Systems, Inc (AOS), uses real-time image correlation to provide relative position and pose data for spacecraft guidance, navigation, and control. Potential data sources include a wide variety of sensors, including visible and infrared cameras. ULTOR(Registered TradeMark) P3E has been demonstrated on a number of host processing platforms. NASA is integrating ULTOR(Registerd TradeMark) P3E into its Relative Navigation System (RNS), which is being developed for the upcoming Hubble Space Telescope (HST) Servicing Mission 4 (SM4). During SM4 ULTOR(Registered TradeMark) P3E will perform realtime pose and position measurements during both the approach and departure phases of the mission. This paper describes the RNS implementation of ULTOR(Registered TradeMark) P3E, and presents results from NASA's hardware-in-the-loop simulation testing against the HST mockup.

  10. Problem-Solving Support for English Language Learners

    ERIC Educational Resources Information Center

    Wiest, Lynda R.

    2008-01-01

    Although word problems pose greater language demands, they also encourage more meaningful problem solving and mathematics understanding. With proper instructional support, a student-centered, investigative approach to contextualized problem solving benefits all students. This article presents a lesson built on an author-adapted version of the…

  11. 49 CFR 173.243 - Bulk packaging for certain high hazard liquids and dual hazard materials which pose a moderate...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Bulk packaging for certain high hazard liquids and dual hazard materials which pose a moderate hazard. 173.243 Section 173.243 Transportation Other... hazard liquids and dual hazard materials which pose a moderate hazard. When § 172.101 of this...

  12. 49 CFR 173.243 - Bulk packaging for certain high hazard liquids and dual hazard materials which pose a moderate...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Bulk packaging for certain high hazard liquids and dual hazard materials which pose a moderate hazard. 173.243 Section 173.243 Transportation Other... hazard liquids and dual hazard materials which pose a moderate hazard. When § 172.101 of this...

  13. 42 CFR 442.117 - Termination of certification for ICFs/MR whose deficiencies pose immediate jeopardy.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Termination of certification for ICFs/MR whose deficiencies pose immediate jeopardy. 442.117 Section 442.117 Public Health CENTERS FOR MEDICARE & MEDICAID... ICFs/MR § 442.117 Termination of certification for ICFs/MR whose deficiencies pose immediate...

  14. 6-DOF Pose Estimation of a Robotic Navigation Aid by Tracking Visual and Geometric Features

    PubMed Central

    Ye, Cang; Hong, Soonhac; Tamjidi, Amirhossein

    2015-01-01

    This paper presents a 6-DOF Pose Estimation (PE) method for a Robotic Navigation Aid (RNA) for the visually impaired. The RNA uses a single 3D camera for PE and object detection. The proposed method processes the camera’s intensity and range data to estimates the camera’s egomotion that is then used by an Extended Kalman Filter (EKF) as the motion model to track a set of visual features for PE. A RANSAC process is employed in the EKF to identify inliers from the visual feature correspondences between two image frames. Only the inliers are used to update the EKF’s state. The EKF integrates the egomotion into the camera’s pose in the world coordinate system. To retain the EKF’s consistency, the distance between the camera and the floor plane (extracted from the range data) is used by the EKF as the observation of the camera’s z coordinate. Experimental results demonstrate that the proposed method results in accurate pose estimates for positioning the RNA in indoor environments. Based on the PE method, a wayfinding system is developed for localization of the RNA in a home environment. The system uses the estimated pose and the floorplan to locate the RNA user in the home environment and announces the points of interest and navigational commands to the user through a speech interface. Note to Practitioners This work was motivated by the limitations of the existing navigation technology for the visually impaired. Most of the existing methods use a point/line measurement sensor for indoor object detection. Therefore, they lack capability in detecting 3D objects and positioning a blind traveler. Stereovision has been used in recent research. However, it cannot provide reliable depth data for object detection. Also, it tends to produce a lower localization accuracy because its depth measurement error quadratically increases with the true distance. This paper suggests a new approach for navigating a blind traveler. The method uses a single 3D time

  15. Self-organizing neural integration of pose-motion features for human action recognition.

    PubMed

    Parisi, German I; Weber, Cornelius; Wermter, Stefan

    2015-01-01

    The visual recognition of complex, articulated human movements is fundamental for a wide range of artificial systems oriented toward human-robot communication, action classification, and action-driven perception. These challenging tasks may generally involve the processing of a huge amount of visual information and learning-based mechanisms for generalizing a set of training actions and classifying new samples. To operate in natural environments, a crucial property is the efficient and robust recognition of actions, also under noisy conditions caused by, for instance, systematic sensor errors and temporarily occluded persons. Studies of the mammalian visual system and its outperforming ability to process biological motion information suggest separate neural pathways for the distinct processing of pose and motion features at multiple levels and the subsequent integration of these visual cues for action perception. We present a neurobiologically-motivated approach to achieve noise-tolerant action recognition in real time. Our model consists of self-organizing Growing When Required (GWR) networks that obtain progressively generalized representations of sensory inputs and learn inherent spatio-temporal dependencies. During the training, the GWR networks dynamically change their topological structure to better match the input space. We first extract pose and motion features from video sequences and then cluster actions in terms of prototypical pose-motion trajectories. Multi-cue trajectories from matching action frames are subsequently combined to provide action dynamics in the joint feature space. Reported experiments show that our approach outperforms previous results on a dataset of full-body actions captured with a depth sensor, and ranks among the best results for a public benchmark of domestic daily actions.

  16. Self-organizing neural integration of pose-motion features for human action recognition

    PubMed Central

    Parisi, German I.; Weber, Cornelius; Wermter, Stefan

    2015-01-01

    The visual recognition of complex, articulated human movements is fundamental for a wide range of artificial systems oriented toward human-robot communication, action classification, and action-driven perception. These challenging tasks may generally involve the processing of a huge amount of visual information and learning-based mechanisms for generalizing a set of training actions and classifying new samples. To operate in natural environments, a crucial property is the efficient and robust recognition of actions, also under noisy conditions caused by, for instance, systematic sensor errors and temporarily occluded persons. Studies of the mammalian visual system and its outperforming ability to process biological motion information suggest separate neural pathways for the distinct processing of pose and motion features at multiple levels and the subsequent integration of these visual cues for action perception. We present a neurobiologically-motivated approach to achieve noise-tolerant action recognition in real time. Our model consists of self-organizing Growing When Required (GWR) networks that obtain progressively generalized representations of sensory inputs and learn inherent spatio-temporal dependencies. During the training, the GWR networks dynamically change their topological structure to better match the input space. We first extract pose and motion features from video sequences and then cluster actions in terms of prototypical pose-motion trajectories. Multi-cue trajectories from matching action frames are subsequently combined to provide action dynamics in the joint feature space. Reported experiments show that our approach outperforms previous results on a dataset of full-body actions captured with a depth sensor, and ranks among the best results for a public benchmark of domestic daily actions. PMID:26106323

  17. An Inertial and Optical Sensor Fusion Approach for Six Degree-of-Freedom Pose Estimation.

    PubMed

    He, Changyu; Kazanzides, Peter; Sen, Hasan Tutkun; Kim, Sungmin; Liu, Yue

    2015-07-08

    Optical tracking provides relatively high accuracy over a large workspace but requires line-of-sight between the camera and the markers, which may be difficult to maintain in actual applications. In contrast, inertial sensing does not require line-of-sight but is subject to drift, which may cause large cumulative errors, especially during the measurement of position. To handle cases where some or all of the markers are occluded, this paper proposes an inertial and optical sensor fusion approach in which the bias of the inertial sensors is estimated when the optical tracker provides full six degree-of-freedom (6-DOF) pose information. As long as the position of at least one marker can be tracked by the optical system, the 3-DOF position can be combined with the orientation estimated from the inertial measurements to recover the full 6-DOF pose information. When all the markers are occluded, the position tracking relies on the inertial sensors that are bias-corrected by the optical tracking system. Experiments are performed with an augmented reality head-mounted display (ARHMD) that integrates an optical tracking system (OTS) and inertial measurement unit (IMU). Experimental results show that under partial occlusion conditions, the root mean square errors (RMSE) of orientation and position are 0.04° and 0.134 mm, and under total occlusion conditions for 1 s, the orientation and position RMSE are 0.022° and 0.22 mm, respectively. Thus, the proposed sensor fusion approach can provide reliable 6-DOF pose under long-term partial occlusion and short-term total occlusion conditions.

  18. D3R grand challenge 2015: Evaluation of protein-ligand pose and affinity predictions

    NASA Astrophysics Data System (ADS)

    Gathiaka, Symon; Liu, Shuai; Chiu, Michael; Yang, Huanwang; Stuckey, Jeanne A.; Kang, You Na; Delproposto, Jim; Kubish, Ginger; Dunbar, James B.; Carlson, Heather A.; Burley, Stephen K.; Walters, W. Patrick; Amaro, Rommie E.; Feher, Victoria A.; Gilson, Michael K.

    2016-09-01

    The Drug Design Data Resource (D3R) ran Grand Challenge 2015 between September 2015 and February 2016. Two targets served as the framework to test community docking and scoring methods: (1) HSP90, donated by AbbVie and the Community Structure Activity Resource (CSAR), and (2) MAP4K4, donated by Genentech. The challenges for both target datasets were conducted in two stages, with the first stage testing pose predictions and the capacity to rank compounds by affinity with minimal structural data; and the second stage testing methods for ranking compounds with knowledge of at least a subset of the ligand-protein poses. An additional sub-challenge provided small groups of chemically similar HSP90 compounds amenable to alchemical calculations of relative binding free energy. Unlike previous blinded Challenges, we did not provide cognate receptors or receptors prepared with hydrogens and likewise did not require a specified crystal structure to be used for pose or affinity prediction in Stage 1. Given the freedom to select from over 200 crystal structures of HSP90 in the PDB, participants employed workflows that tested not only core docking and scoring technologies, but also methods for addressing water-mediated ligand-protein interactions, binding pocket flexibility, and the optimal selection of protein structures for use in docking calculations. Nearly 40 participating groups submitted over 350 prediction sets for Grand Challenge 2015. This overview describes the datasets and the organization of the challenge components, summarizes the results across all submitted predictions, and considers broad conclusions that may be drawn from this collaborative community endeavor.

  19. ProPose: a docking engine based on a fully configurable protein-ligand interaction model.

    PubMed

    Seifert, Markus H J; Schmitt, Frank; Herz, Thomas; Kramer, Bernd

    2004-12-01

    Virtual high-throughput screening of molecular databases and in particular high-throughput protein-ligand docking are both common methodologies that identify and enrich hits in the early stages of the drug design process. Current protein-ligand docking algorithms often implement a program-specific model for protein-ligand interaction geometries. However, in order to create a platform for arbitrary queries in molecular databases, a new program is desirable that allows more manual control of the modeling of molecular interactions. For that reason, ProPose, an advanced incremental construction docking engine, is presented here that implements a fast and fully configurable molecular interaction and scoring model. This program uses user-defined, discrete, pharmacophore-like representations of molecular interactions that are transformed on-the-fly into a continuous potential energy surface, allowing for the incorporation of target specific interaction mechanisms into docking protocols in a straightforward manner. A torsion angle library, based on semi-empirical quantum chemistry calculations, is used to provide minimum energy torsion angles for the incremental construction algorithm. Docking results of a diverse set of protein-ligand complexes from the Protein Data Bank demonstrate the feasibility of this new approach. As a result, the seamless integration of pharmacophore-like interaction types into the docking and scoring scheme implemented in ProPose opens new opportunities for efficient, receptor-specific screening protocols. [figure: see text]. ProPose--a fully configurable protein-ligand docking program--transforms pharmacophores into a smooth potential energy surface.

  20. Object recognition and pose estimation of planar objects from range data

    NASA Technical Reports Server (NTRS)

    Pendleton, Thomas W.; Chien, Chiun Hong; Littlefield, Mark L.; Magee, Michael

    1994-01-01

    The Extravehicular Activity Helper/Retriever (EVAHR) is a robotic device currently under development at the NASA Johnson Space Center that is designed to fetch objects or to assist in retrieving an astronaut who may have become inadvertently de-tethered. The EVAHR will be required to exhibit a high degree of intelligent autonomous operation and will base much of its reasoning upon information obtained from one or more three-dimensional sensors that it will carry and control. At the highest level of visual cognition and reasoning, the EVAHR will be required to detect objects, recognize them, and estimate their spatial orientation and location. The recognition phase and estimation of spatial pose will depend on the ability of the vision system to reliably extract geometric features of the objects such as whether the surface topologies observed are planar or curved and the spatial relationships between the component surfaces. In order to achieve these tasks, three-dimensional sensing of the operational environment and objects in the environment will therefore be essential. One of the sensors being considered to provide image data for object recognition and pose estimation is a phase-shift laser scanner. The characteristics of the data provided by this scanner have been studied and algorithms have been developed for segmenting range images into planar surfaces, extracting basic features such as surface area, and recognizing the object based on the characteristics of extracted features. Also, an approach has been developed for estimating the spatial orientation and location of the recognized object based on orientations of extracted planes and their intersection points. This paper presents some of the algorithms that have been developed for the purpose of recognizing and estimating the pose of objects as viewed by the laser scanner, and characterizes the desirability and utility of these algorithms within the context of the scanner itself, considering data quality and

  1. Infectious diseases that pose specific challenges after natural disasters: a review.

    PubMed

    Ligon, B Lee

    2006-01-01

    In a time span of less than one year, December 2004 to October 2005, several natural disasters of extreme proportions struck different areas of the world, causing unparalleled destruction and loss of lives and property. In each of these instances, the potential existed for acquisition of infectious diseases caused by bacteria, viruses, mold, and mildew and demonstrated that such disasters represent a public health concern, which is exacerbated by the fact that many factors may work synergistically to increase the risk of morbidity and mortality caused by communicable diseases. This article reviews causes, symptoms, and treatments of various infectious diseases that pose a threat in the event of a natural disaster.

  2. STS-46 ESA MS Nicollier and PLC Hoffman pose on OV-104's aft flight deck

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-46 European Space Agency (ESA) Mission Specialist (MS) Claude Nicollier (left) and MS and Payload Commander (PLC) Jeffrey A. Hoffman pose in front of the onorbit station controls on the aft flight deck of Atlantis, Orbiter Vehicle (OV) 104. The overhead windows W7 and W8 appear above their heads and the aft flight deck viewing windows W9 and W10 behind them. Hoffman and Nicollier have been training together for a dozen years at JSC. Hoffman was an astronaut candidate in 1978 and Nicollier accompanied a group of trainees in 1980. Note the partially devoured chocolate Space Shuttle floating near the two.

  3. Estimating Vehicle Pose Relative to Current Lane from Fisheye Camera System

    NASA Astrophysics Data System (ADS)

    Li, Shigang; Oshima, Hideki; Nakanishi, Isao

    A fisheye camera system is usually used for eliminating the blind spot around a vehicle. In this paper we propose a method of estimating vehicle pose relative to current lane from the side fisheye cameras of such a fisheye camera system. The side fisheye camera with hemispherical field of view can observe the side boundary of the vehicle and the lane markings simultaneously. An algorithm of estimating the distance and the relative orientation between the vehicle and the current lane is presented based on the side boundary of the vehicle and the nearest lane marking. The experimental results are also presented to show the effectiveness of the proposed method.

  4. STS-30 crewmembers pose for onboard portrait on OV-104's aft flight deck

    NASA Technical Reports Server (NTRS)

    1989-01-01

    During STS-30 aboard Atlantis, Orbiter Vehicle (OV) 104, crewmembers pose for portrait. In front of aft flight deck onorbit station are (right to left) Mission Specialist (MS) Norman E. Thagard, Pilot Ronald J. Grabe, MS Mary L. Cleave, Commander David M. Walker, and MS Mark C. Lee. Crewmembers are wearing red, white, and blue mission polo shirts and light blue flight coveralls. Overhead windows W7 and W8 and aft flight deck viewing windows W9 and W10 are visible in view.

  5. STS-41 crewmembers pose on OV-103's middeck for inflight (in-space) portrait

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-41 crewmembers pose on Discovery's, Orbiter Vehicle (OV) 103's, middeck for inflight (in-space) portrait. In front are (left to right) Commander Richard N. Richards and Pilot Robert D. Cabana. In the rear are (left to right) Mission Specialist (MS) Thomas D. Akers, MS Bruce E. Melnick, and MS William M. Shepherd. Displayed behind the crew, on the port side galley, are various insignias and decals including Fly Navy, Coast Guard Academy, United States Marine Corp, University of Missouri Rolla, and Navy Frogman.

  6. STS-55 Columbia, OV-102, crew poses for onboard portrait in SL-D2 module

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-55 Columbia, Orbiter Vehicle (OV) 102, crewmembers pose for their traditional onboard (inflight) portrait in the Spacelab Deutsche 2 (SL-D2) science module. Front (left to right) are Pilot Terence T. Henricks, Commander Steven R. Nagel, German Payload Specialist 1 Ulrich Walter, and Mission Specialist 2 (MS2) Charles J. Precourt. In the rear (left to right) are MS3 Bernard A. Harris, Jr, German Payload Specialist 2 Hans Schlegel, and MS1 and Payload Commander (PLC) Jerry L. Ross. Walter and Schlegel represent the German Aerospace Research Establishment (DLR).

  7. Ms. Rodriquez and Mickey Mouse pose with a portrait of Ronald McNair

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In the gymnasium of Ronald McNair Magnet School in Cocoa, Fla., Ms. Maria Rodriguez, an Walt Disney World Ambassador, and Mickey Mouse pose with a portrait of NASA astronaut Ronald McNair. The portrait was presented to the school by Walt Disney World during a tribute to McNair. The school had previously been renamed for the fallen astronaut, who was one of a crew of seven who lost their lives during an accident following launch of the Space Shuttle Challenger in January 1986.

  8. STS-31 crew poses on EAFB concrete runway after egressing OV-103

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-31 crewmembers, wearing their launch and entry suits (LESs), pose for an informal portrait on Edwards Air Force Base (EAFB) concrete runway 22 after egressing Discovery, Orbiter Vehicle (OV) 103. Left to right are Mission Specialist (MS) Steven A. Hawley, Pilot Charles F. Bolden, MS Kathryn D. Sullivan, Commander Loren J. Shriver, and MS Bruce McCandless II. A service vehicle and OV-103's main landing gear (MLG) are visible in the background. The highly successful five-day mission concluded at EAFB with wheel stop at 6:51:00 am (Pacific Daylight Time (PDT)).

  9. Implicit Theories about Everyday Problem Solving.

    ERIC Educational Resources Information Center

    Herbert, Margaret E.; Dionne, Jean-Paul

    Mental models or implicit theories held by adults about everyday problem solving were studied. Research questions were posed to 12 male and 12 female adults, aged 25 to 60 years, from a wide range of educational and occupational orientations. Subjects were interviewed in pairs. Verbal Protocol Analysis was used to analyze the data from two…

  10. Minimal Solutions to the Box Problem

    ERIC Educational Resources Information Center

    Chuang, Jer-Chin

    2009-01-01

    The "box problem" from introductory calculus seeks to maximize the volume of a tray formed by folding a strictly rectangular sheet from which identical squares have been cut from each corner. In posing such questions, one would like to choose integral side-lengths for the sheet so that the excised squares have rational or integral side-length.…

  11. Walking Problems

    MedlinePlus

    ... Parkinson's disease Diseases such as arthritis or multiple sclerosis Vision or balance problems Treatment of walking problems depends on the cause. Physical therapy, surgery, or mobility aids may help.

  12. Evaluating the tuberculosis hazard posed to cattle from wildlife across Europe.

    PubMed

    Hardstaff, Joanne L; Marion, Glenn; Hutchings, Michael R; White, Piran C L

    2014-10-01

    Tuberculosis (TB) caused by infection with Mycobacterium bovis (M. bovis) and other closely related members of the M. tuberculosis complex (MTC) infects many domestic and wildlife species across Europe. Transmission from wildlife species to cattle complicates the control of disease in cattle. By determining the level of TB hazard for which a given wildlife species is responsible, the potential for transmission to the cattle population can be evaluated. We undertook a quantitative review of TB hazard across Europe on a country-by-country basis for cattle and five widely-distributed wildlife species. Cattle posed the greatest current and potential TB hazard other cattle for the majority of countries in Europe. Wild boar posed the greatest hazard of all the wildlife species, indicating that wild boar have the greatest ability to transmit the disease to cattle. The most common host systems for TB hazards in Europe are the cattle-deer-wild boar ones. The cattle-roe deer-wild boar system is found in 10 countries, and the cattle-red deer-wild boar system is found in five countries. The dominance of cattle with respect to the hazards in many regions confirms that intensive surveillance of cattle for TB should play an important role in any TB control programme. The significant contribution that wildlife can make to the TB hazard to cattle is also of concern, given current population and distribution increases of some susceptible wildlife species, especially wild boar and deer, and the paucity of wildlife TB surveillance programmes.

  13. Assessing the potential risks to zebrafish posed by environmentally relevant copper and silver nanoparticles.

    PubMed

    Chio, Chia-Pin; Chen, Wei-Yu; Chou, Wei-Chun; Hsieh, Nan-Hung; Ling, Min-Pei; Liao, Chung-Min

    2012-03-15

    The manufacture of large quantities of engineered nanomaterials (NMs) may lead to unintended contamination of aquatic ecosystems. Biologically based monitoring techniques need to be developed to detect these emerging NMs. The purpose of this study was to develop a risk-based probability model to predict the potential hazards of nanoecotoxicity toward aquatic organisms posed by waterborne copper and silver nanoparticles (Cu/Ag NPs). Published experimental evidence based on Cu/Ag NP-zebrafish (Danio rerio) systems was adopted as the study data. A Hill model was used to reconstruct a concentration-mortality response profile. A cumulative Weibull predictive model was employed to estimate exposure thresholds. The derived probabilistic model can predict the potential risk of environmentally relevant Cu/Ag NPs for major Taiwanese rivers with predicted environmental concentrations of 0.06 (95% confidence interval (CI): 0.01-0.92) mgL(-1) for Cu NPs and 0.04 (0.01-0.11) mgL(-1) for Ag NPs. The results indicated that estimated thresholds were 0.10-0.48mgL(-1) (95% CI) for Cu NPs and 2.69-2.73mgL(-1) for Ag NPs. The probabilities of a risk quotient (RQ) of >1 ranged 17%-81% for zebrafish exposed to Cu NPs. This study found that Ag NP exposure scenarios posed no significant risks to zebrafish (RQ≪0.1).

  14. A pose-based structural dynamic model updating method for serial modular robots

    NASA Astrophysics Data System (ADS)

    Mohamed, Richard Phillip; Xi, Fengfeng (Jeff); Chen, Tianyan

    2017-02-01

    A new approach is presented for updating the structural dynamic component models of serial modular robots using experimental data from component tests such that the updated model of the entire robot assembly can provide accurate results in any pose. To accomplish this, a test-analysis component mode synthesis (CMS) model with fixed-free component boundaries is implemented to directly compare measured frequency response functions (FRFs) from vibration experiments of individual modules. The experimental boundary conditions are made to emulate module connection interfaces and can enable individual joint and link modules to be tested in arbitrary poses. By doing so, changes in the joint dynamics can be observed and more FRF data points can be obtained from experiments to be used in the updating process. Because this process yields an overdetermined system of equations, a direct search method with nonlinear constraints on the resonances and antiresonances is used to update the FRFs of the analytical component models. The effectiveness of the method is demonstrated with experimental case studies on an adjustable modular linkage system. Overall, the method can enable virtual testing of modular robot systems without the need to perform further testing on entire assemblies.

  15. A Simulation Environment for Benchmarking Sensor Fusion-Based Pose Estimators

    PubMed Central

    Ligorio, Gabriele; Sabatini, Angelo Maria

    2015-01-01

    In-depth analysis and performance evaluation of sensor fusion-based estimators may be critical when performed using real-world sensor data. For this reason, simulation is widely recognized as one of the most powerful tools for algorithm benchmarking. In this paper, we present a simulation framework suitable for assessing the performance of sensor fusion-based pose estimators. The systems used for implementing the framework were magnetic/inertial measurement units (MIMUs) and a camera, although the addition of further sensing modalities is straightforward. Typical nuisance factors were also included for each sensor. The proposed simulation environment was validated using real-life sensor data employed for motion tracking. The higher mismatch between real and simulated sensors was about 5% of the measured quantity (for the camera simulation), whereas a lower correlation was found for an axis of the gyroscope (0.90). In addition, a real benchmarking example of an extended Kalman filter for pose estimation from MIMU and camera data is presented. PMID:26703603

  16. Comparison of several molecular docking programs: pose prediction and virtual screening accuracy.

    PubMed

    Cross, Jason B; Thompson, David C; Rai, Brajesh K; Baber, J Christian; Fan, Kristi Yi; Hu, Yongbo; Humblet, Christine

    2009-06-01

    Molecular docking programs are widely used modeling tools for predicting ligand binding modes and structure based virtual screening. In this study, six molecular docking programs (DOCK, FlexX, GLIDE, ICM, PhDOCK, and Surflex) were evaluated using metrics intended to assess docking pose and virtual screening accuracy. Cognate ligand docking to 68 diverse, high-resolution X-ray complexes revealed that ICM, GLIDE, and Surflex generated ligand poses close to the X-ray conformation more often than the other docking programs. GLIDE and Surflex also outperformed the other docking programs when used for virtual screening, based on mean ROC AUC and ROC enrichment values obtained for the 40 protein targets in the Directory of Useful Decoys (DUD). Further analysis uncovered general trends in accuracy that are specific for particular protein families. Modifying basic parameters in the software was shown to have a significant effect on docking and virtual screening results, suggesting that expert knowledge is critical for optimizing the accuracy of these methods.

  17. Correlation techniques as applied to pose estimation in space station docking

    NASA Astrophysics Data System (ADS)

    Rollins, John M.; Juday, Richard D.; Monroe, Stanley E., Jr.

    2002-08-01

    The telerobotic assembly of space-station components has become the method of choice for the International Space Station (ISS) because it offers a safe alternative to the more hazardous option of space walks. The disadvantage of telerobotic assembly is that it does not necessarily provide for direct arbitrary views of mating interfaces for the teleoperator. Unless cameras are present very close to the interface positions, such views must be generated graphically, based on calculated pose relationships derived from images. To assist in this photogrammetric pose estimation, circular targets, or spots, of high contrast have been affixed on each connecting module at carefully surveyed positions. The appearance of a subset of spots must form a constellation of specific relative positions in the incoming image stream in order for the docking to proceed. Spot positions are expressed in terms of their apparent centroids in an image. The precision of centroid estimation is required to be as fine as 1/20th pixel, in some cases. This paper presents an approach to spot centroid estimation using cross correlation between spot images and synthetic spot models of precise centration. Techniques for obtaining sub-pixel accuracy and for shadow and lighting irregularity compensation are discussed.

  18. First evaluation of the threat posed by antifouling biocides in the Southern Adriatic Sea.

    PubMed

    Manzo, Sonia; Ansanelli, Giuliana; Parrella, Luisa; Di Landa, Giuseppe; Massanisso, Paolo; Schiavo, Simona; Minopoli, Carmine; Lanza, Bruno; Boggia, Raffaella; Aleksi, Pellumb; Tabaku, Afrim

    2014-08-01

    The CARISMA project (characterization and ecological risk analysis of antifouling biocides in the Southern Adriatic Sea) aims to appraise the quality of the Southern Adriatic Sea between Italy (Apulia region) and Albania and, in particular, the impact due to the use of biocidal antifouling coatings. Under this project, a preliminary survey at the main hot spots of contamination (e.g. ports and marinas) was conducted at the end of the nautical season in 2012. Chemical seawater analyses were complemented with ecotoxicological assays and the results were analyzed by principal component analysis (PCA). As expected, PCA splits the Albanian and Italian ports, according to the different degrees of contamination indicated for the two countries by the experimental data, highlighting the most critical situation in one port of Apulia. In addition, in order to assess the potential adverse ecological effects posed by antifouling agents (i.e. tributyltin (TBT)-irgarol-diuron) on non-target marine organisms, hazard quotients (HQ) were calculated. The results showed a low risk posed by irgarol and diuron whereas the probability of adverse effects was high in the case of TBT.

  19. Head pose free 3D gaze estimation using RGB-D camera

    NASA Astrophysics Data System (ADS)

    Kacete, Amine; Séguier, Renaud; Collobert, Michel; Royan, Jérôme

    2017-02-01

    In this paper, we propose an approach for 3D gaze estimation under head pose variation using RGB-D camera. Our method uses a 3D eye model to determine the 3D optical axis and infer the 3D visual axis. For this, we estimate robustly user head pose parameters and eye pupil locations with an ensembles of randomized trees trained with an important annotated training sets. After projecting eye pupil locations in the sensor coordinate system using the sensor intrinsic parameters and a one-time simple calibration by gazing a known 3D target under different directions, the 3D eyeball centers are determined for a specific user for both eyes yielding the determination of the visual axis. Experimental results demonstrate that our method shows a good gaze estimation accuracy even if the environment is highly unconstrained namely large user-sensor distances (> 1m50) unlike state-of-the-art methods which deal with relatively small distances (<1m).

  20. Handheld pose tracking using vision-inertial sensors with occlusion handling

    NASA Astrophysics Data System (ADS)

    Li, Juan; Slembrouck, Maarten; Deboeverie, Francis; Bernardos, Ana M.; Besada, Juan A.; Veelaert, Peter; Aghajan, Hamid; Casar, José R.; Philips, Wilfried

    2016-07-01

    Tracking of a handheld device's three-dimensional (3-D) position and orientation is fundamental to various application domains, including augmented reality (AR), virtual reality, and interaction in smart spaces. Existing systems still offer limited performance in terms of accuracy, robustness, computational cost, and ease of deployment. We present a low-cost, accurate, and robust system for handheld pose tracking using fused vision and inertial data. The integration of measurements from embedded accelerometers reduces the number of unknown parameters in the six-degree-of-freedom pose calculation. The proposed system requires two light-emitting diode (LED) markers to be attached to the device, which are tracked by external cameras through a robust algorithm against illumination changes. Three data fusion methods have been proposed, including the triangulation-based stereo-vision system, constraint-based stereo-vision system with occlusion handling, and triangulation-based multivision system. Real-time demonstrations of the proposed system applied to AR and 3-D gaming are also included. The accuracy assessment of the proposed system is carried out by comparing with the data generated by the state-of-the-art commercial motion tracking system OptiTrack. Experimental results show that the proposed system has achieved high accuracy of few centimeters in position estimation and few degrees in orientation estimation.

  1. Lumbar spine segmentation using a statistical multi-vertebrae anatomical shape+pose model.

    PubMed

    Rasoulian, Abtin; Rohling, Robert; Abolmaesumi, Purang

    2013-10-01

    Segmentation of the spinal column from computed tomography (CT) images is a preprocessing step for a range of image-guided interventions. One intervention that would benefit from accurate segmentation is spinal needle injection. Previous spinal segmentation techniques have primarily focused on identification and separate segmentation of each vertebra. Recently, statistical multi-object shape models have been introduced to extract common statistical characteristics between several anatomies. These models can be used for segmentation purposes because they are robust, accurate, and computationally tractable. In this paper, we develop a statistical multi-vertebrae shape+pose model and propose a novel registration-based technique to segment the CT images of spine. The multi-vertebrae statistical model captures the variations in shape and pose simultaneously, which reduces the number of registration parameters. We validate our technique in terms of accuracy and robustness of multi-vertebrae segmentation of CT images acquired from lumbar vertebrae of 32 subjects. The mean error of the proposed technique is below 2 mm, which is sufficient for many spinal needle injection procedures, such as facet joint injections.

  2. Posed versus spontaneous facial expressions are modulated by opposite cerebral hemispheres.

    PubMed

    Ross, Elliott D; Pulusu, Vinay K

    2013-05-01

    Clinical research has indicated that the left face is more expressive than the right face, suggesting that modulation of facial expressions is lateralized to the right hemisphere. The findings, however, are controversial because the results explain, on average, approximately 4% of the data variance. Using high-speed videography, we sought to determine if movement-onset asymmetry was a more powerful research paradigm than terminal movement asymmetry. The results were very robust, explaining up to 70% of the data variance. Posed expressions began overwhelmingly on the right face whereas spontaneous expressions began overwhelmingly on the left face. This dichotomy was most robust for upper facial expressions. In addition, movement-onset asymmetries did not predict terminal movement asymmetries, which were not significantly lateralized. The results support recent neuroanatomic observations that upper versus lower facial movements have different forebrain motor representations and recent behavioral constructs that posed versus spontaneous facial expressions are modulated preferentially by opposite cerebral hemispheres and that spontaneous facial expressions are graded rather than non-graded movements.

  3. A Model-Based 3D Template Matching Technique for Pose Acquisition of an Uncooperative Space Object

    PubMed Central

    Opromolla, Roberto; Fasano, Giancarmine; Rufino, Giancarlo; Grassi, Michele

    2015-01-01

    This paper presents a customized three-dimensional template matching technique for autonomous pose determination of uncooperative targets. This topic is relevant to advanced space applications, like active debris removal and on-orbit servicing. The proposed technique is model-based and produces estimates of the target pose without any prior pose information, by processing three-dimensional point clouds provided by a LIDAR. These estimates are then used to initialize a pose tracking algorithm. Peculiar features of the proposed approach are the use of a reduced number of templates and the idea of building the database of templates on-line, thus significantly reducing the amount of on-board stored data with respect to traditional techniques. An algorithm variant is also introduced aimed at further accelerating the pose acquisition time and reducing the computational cost. Technique performance is investigated within a realistic numerical simulation environment comprising a target model, LIDAR operation and various target-chaser relative dynamics scenarios, relevant to close-proximity flight operations. Specifically, the capability of the proposed techniques to provide a pose solution suitable to initialize the tracking algorithm is demonstrated, as well as their robustness against highly variable pose conditions determined by the relative dynamics. Finally, a criterion for autonomous failure detection of the presented techniques is presented. PMID:25785309

  4. A model-based 3D template matching technique for pose acquisition of an uncooperative space object.

    PubMed

    Opromolla, Roberto; Fasano, Giancarmine; Rufino, Giancarlo; Grassi, Michele

    2015-03-16

    This paper presents a customized three-dimensional template matching technique for autonomous pose determination of uncooperative targets. This topic is relevant to advanced space applications, like active debris removal and on-orbit servicing. The proposed technique is model-based and produces estimates of the target pose without any prior pose information, by processing three-dimensional point clouds provided by a LIDAR. These estimates are then used to initialize a pose tracking algorithm. Peculiar features of the proposed approach are the use of a reduced number of templates and the idea of building the database of templates on-line, thus significantly reducing the amount of on-board stored data with respect to traditional techniques. An algorithm variant is also introduced aimed at further accelerating the pose acquisition time and reducing the computational cost. Technique performance is investigated within a realistic numerical simulation environment comprising a target model, LIDAR operation and various target-chaser relative dynamics scenarios, relevant to close-proximity flight operations. Specifically, the capability of the proposed techniques to provide a pose solution suitable to initialize the tracking algorithm is demonstrated, as well as their robustness against highly variable pose conditions determined by the relative dynamics. Finally, a criterion for autonomous failure detection of the presented techniques is presented.

  5. Winners, losers, and posers: The effect of power poses on testosterone and risk-taking following competition.

    PubMed

    Smith, Kristopher M; Apicella, Coren L

    2016-11-10

    A contribution to a special issue on Hormones and Human Competition. The effect of postural power displays (i.e. power poses) on hormone levels and decision-making has recently been challenged. While Carney et al. (2010) found that holding brief postural displays of power leads to increased testosterone, decreased cortisol and greater economic risk taking, this failed to replicate in a recent high-powered study (Ranehill et al. 2015). It has been put forward that subtle differences in social context may account for the differences in results. Power displays naturally occur within the context of competitions, as do changes in hormones, and researchers have yet to examine the effects of poses within this ecologically relevant context. Using a large sample of 247 male participants, natural winners and losers of a physical competition were randomly assigned to hold a low, neutral or high-power postural display. We found no main effect of pose type on testosterone, cortisol, risk or feelings of power. Winners assigned to a high-power pose had a relative, albeit small, rise in testosterone compared to winners who held neutral or low-power poses. For losers, we found little evidence that high-power poses lead to increased testosterone relative to those holding neutral or low-powered poses. If anything, the reverse was observed - losers had a reduction in testosterone after holding high-power poses. To the extent that changes in testosterone modulate social behaviors adaptively, it is possible that the relative reduction in testosterone observed in losers taking high-powered poses is designed to inhibit further "winner-like" behavior that could result in continued defeat and harm. Still, effects were small, multiple comparisons were made, and the results ran counter to our predictions. We thus treat these conclusions as preliminary.

  6. Mobile serious games for collaborative problem solving.

    PubMed

    Sanchez, Jaime; Mendoza, Claudia; Salinas, Alvaro

    2009-01-01

    This paper presents the results obtained from the implementation of a series of learning activities based on mobile serious games (MSG) for the development of problem-solving and collaborative skills in Chilean 8th grade students. Three MSGs were developed and played by teams of four students, who had to solve the problems posed by the game collaboratively. The data shows that the experimental group had a higher perception of their own skills of collaboration and of the plan execution dimension of problem solving than the control group, providing empirical evidence regarding the contribution of MSGs to the development of collaborative problem-solving skills.

  7. The Problems of Problem Solving

    ERIC Educational Resources Information Center

    Watson, Charles E.

    1976-01-01

    Discusses some common pitfalls in problem-solving and outlines three basic approaches to successfully identifying problems and their causes. (Available from Business Horizons, School of Business, Indiana University, Bloomington, Indiana 47401; $2.50, single copy) (Author/JG)

  8. Binding Ensemble PROfiling with (F)photoaffinity Labeling (BEProFL) Approach: Mapping the Binding Poses of HDAC8 Inhibitors

    PubMed Central

    He, Bai; Velaparthi, Subash; Pieffet, Gilles; Pennington, Chris; Mahesh, Aruna; Holzle, Denise L.; Brunsteiner, Michael; van Breemen, Richard; Blond, Sylvie Y.; Petukhov, Pavel A.

    2009-01-01

    A Binding Ensemble PROfiling with (F)photoaffinity Labeling (BEProFL) approach that utilizes photolabeling of HDAC8 with a probe containing a UV-activated aromatic azide, mapping the covalent modifications by liquid chromatography-tandem mass-spectrometry, and a computational method to characterize the multiple binding poses of the probe is described. Using the BEProFL approach two distinct binding poses of the HDAC8 probe were identified. The data also suggest that an “upside-down” pose with the surface binding group of the probe bound in an alternative pocket near the catalytic site may contribute to the binding. PMID:19886628

  9. H6 Influenza Viruses Pose a Potential Threat to Human Health

    PubMed Central

    Wang, Guojun; Deng, Guohua; Shi, Jianzhong; Luo, Weiyu; Zhang, Guoquan; Zhang, Qianyi; Liu, Liling; Jiang, Yongping; Li, Chengjun; Sriwilaijaroen, Nongluk; Hiramatsu, Hiroaki; Suzuki, Yasuo; Kawaoka, Yoshihiro

    2014-01-01

    ABSTRACT Influenza viruses of the H6 subtype have been isolated from wild and domestic aquatic and terrestrial avian species throughout the world since their first detection in a turkey in Massachusetts in 1965. Since 1997, H6 viruses with different neuraminidase (NA) subtypes have been detected frequently in the live poultry markets of southern China. Although sequence information has been gathered over the last few years, the H6 viruses have not been fully biologically characterized. To investigate the potential risk posed by H6 viruses to humans, here we assessed the receptor-binding preference, replication, and transmissibility in mammals of a series of H6 viruses isolated from live poultry markets in southern China from 2008 to 2011. Among the 257 H6 strains tested, 87 viruses recognized the human type receptor. Genome sequence analysis of 38 representative H6 viruses revealed 30 different genotypes, indicating that these viruses are actively circulating and reassorting in nature. Thirty-seven of 38 viruses tested in mice replicated efficiently in the lungs and some caused mild disease; none, however, were lethal. We also tested the direct contact transmission of 10 H6 viruses in guinea pigs and found that 5 viruses did not transmit to the contact animals, 3 viruses transmitted to one of the three contact animals, and 2 viruses transmitted to all three contact animals. Our study demonstrates that the H6 avian influenza viruses pose a clear threat to human health and emphasizes the need for continued surveillance and evaluation of the H6 influenza viruses circulating in nature. IMPORTANCE Avian influenza viruses continue to present a challenge to human health. Research and pandemic preparedness have largely focused on the H5 and H7 subtype influenza viruses in recent years. Influenza viruses of the H6 subtype have been isolated from wild and domestic aquatic and terrestrial avian species throughout the world since their first detection in the United States in

  10. Complete Parameter Identification of Gough-Stewart Platform with Partial Pose Measurements

    NASA Astrophysics Data System (ADS)

    Rauf, Abdul; Ryu, Jeha

    Kinematic calibration of Gough-Stewart platform using a new measurement device is presented in this paper. The device simultaneously measures components of position and orientation using commercially available gadgets. Additional kinematic parameters are defined to model the sources of inaccuracies for the proposed measurement device. Computer simulations reveal that all kinematic parameters of the Gough-Stewart platform and the additional kinematic parameters of the measurement device can be identified with the partial pose measurements from the proposed device. Results also show that identification is robust for the initial errors in the parameters and the noise in measurements. The device is general and can be used for other parallel manipulators. The measurement procedure can easily be automated with the proposed measurement device.

  11. Parental allergic disease before and after child birth poses similar risk for childhood allergies.

    PubMed

    Fuertes, E; Standl, M; von Berg, A; Lehmann, I; Hoffmann, B; Bauer, C-P; Koletzko, S; Berdel, D; Heinrich, J

    2015-07-01

    Whether the strength of associations between parental and child allergic diseases differs by whether the first onset of the parental disease is before or after a child's birth has never been examined and is the aim of this study. Yearly childhood asthma, allergic rhinitis, and eczema diagnoses were longitudinally regressed against the effect of a parental disease (pre- vs post-child birth) of the same type separately for each parent using generalized estimation equations. Both a maternal and paternal history of asthma were associated with childhood asthma prevalence up to 15 years of age. Effect estimates were similar for parental asthma with first onset before and after the birth of the child. The results for allergic rhinitis and eczema were less consistent. Parental allergic diseases with first onsets before and after the birth of a child both pose risks to childhood allergic disease in the offspring, especially for asthma.

  12. STS-47 crew and backups pose for portrait in SLJ module at KSC during training

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, crewmembers and backup payload specialists, wearing clean suits, pose for a group portrait in the Spacelab Japan (SLJ) module. The team is at the Kennedy Space Center's (KSC's) Orbiter Processing Facility (OPF) to inspect SLJ configuration and OV-105 preparations. Kneeling, from left, are backup Payload Specialist Chiaki Naito-Mukai; Mission Specialist (MS) N. Jan Davis; and backup Payload Specialist Takao Doi. Standing, from the left, are Pilot Curtis L. Brown,Jr; MS and Payload Commander Mark C. Lee; MS Jerome Apt; Payload Specialist Mamoru Mohri; Commander Robert L. Gibson; MS Mae C. Jemison; and backup Payload Specialist Stanely L. Koszelak. Mohri, Mukai, and Doi represent the National Space Development Agency of Japan (NASDA). View provided by KSC with alternate KSC number KSC-92PC-1647.

  13. Integration of a Generalised Building Model Into the Pose Estimation of Uas Images

    NASA Astrophysics Data System (ADS)

    Unger, J.; Rottensteiner, F.; Heipke, C.

    2016-06-01

    A hybrid bundle adjustment is presented that allows for the integration of a generalised building model into the pose estimation of image sequences. These images are captured by an Unmanned Aerial System (UAS) equipped with a camera flying in between the buildings. The relation between the building model and the images is described by distances between the object coordinates of the tie points and building model planes. Relations are found by a simple 3D distance criterion and are modelled as fictitious observations in a Gauss-Markov adjustment. The coordinates of model vertices are part of the adjustment as directly observed unknowns which allows for changes in the model. Results of first experiments using a synthetic and a real image sequence demonstrate improvements of the image orientation in comparison to an adjustment without the building model, but also reveal limitations of the current state of the method.

  14. STS-107 crew poses for a group portrait with their instructor inside an M113

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The STS-107 crew poses for a group portrait with their instructor inside an M113 armored personnel carrier. The crew is participating in Terminal Countdown Demonstration Test activities, a standard part of launch preparations. From left to right are Pilot William 'Willie' McCool, Commander Rick Husband, Mission Specialist Laurel Clark, Instructor George Hoggard, Mission Specialist Kalpana Chawla, Payload Specialist Ilan Ramon (the first Israeli astronaut), Payload Commander Michael Anderson, and Mission Specialist David Brown. STS-107 is a mission devoted to research and will include more than 80 experiments that will study Earth and space science, advanced technology development, and astronaut health and safety. Launch is planned for Jan. 16, 2003, between 10 a.m. and 2 p.m. EST aboard Space Shuttle Columbia.

  15. STS-107 crew poses for a group portrait during TCDT M113 training activities

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- -- The STS-107 crew poses for a group portrait with their instructor beside an M113 armored personnel carrier. The crew is participating in Terminal Countdown Demonstration Test activities, a standard part of launch preparations. In the front, from left, are Payload Specialist Ilan Ramon (the first Israeli astronaut), Instructor George Hoggard, Mission Specialist Laurel Clark, Commander Rick Husband, Mission Specialist David Brown, and Payload Commander Michael Anderson. In the back, from left, are Mission Specialist Kalpana Chawla and Pilot William 'Willie' McCool. STS-107 is a mission devoted to research and will include more than 80 experiments that will study Earth and space science, advanced technology development, and astronaut health and safety. Launch is planned for Jan. 16, 2003, between 10 a.m. and 2 p.m. EST aboard Space Shuttle Columbia.

  16. STS-107 crew poses for a group portrait with VAB in background

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The STS-107 crew poses for a group portrait with the Vehicle Assembly Building in the background. They are at KSC to take part in Terminal Countdown Demonstration Test activities, a standard part of launch preparations. From left to right are Mission Specialists Kalpana Chawla and Laurel Clark, Pilot William 'Willie' McCool, Commander Rick Husband, Mission Specialist David Brown, Payload Specialist Ilan Ramon (the first Israeli astronaut), and Payload Commander Michael Anderson. STS-107 is a mission devoted to research and will include more than 80 experiments that will study Earth and space science, advanced technology development, and astronaut health and safety. Launch is targeted for Jan. 16, 2003, between 10 a.m. and 2 p.m. EST.

  17. STS-89 M.S. Andrew Thomas, poses the day before launch

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-89 Mission Specialist Andrew Thomas, Ph.D., poses at KSC's Launch Pad 39A wearing a miniature koala bear on the day before the scheduled launch of Space Shuttle Endeavour that will carry him up to the Russian Space Station Mir. Final preparations are under way toward liftoff on Jan. 22 on the eighth mission to dock with Mir. After docking, Dr. Thomas will transfer to the space station, succeeding David Wolf, M.D., who will return to Earth aboard Endeavour. Dr. Thomas, who was born and educated in South Australia, will live and work on Mir until June. STS-89 is scheduled for liftoff at 9:48 p.m. EST.

  18. Simulation of Hazards and Poses for a Rocker-Bogie Rover

    NASA Technical Reports Server (NTRS)

    Backes, Paul; Norris, Jeffrey; Powell, Mark; Tharp, Gregory

    2004-01-01

    Provisions for specification of hazards faced by a robotic vehicle (rover) equipped with a rocker-bogie suspension, for prediction of collisions between the vehicle and the hazards, and for simulation of poses of the vehicle at selected positions on the terrain have been incorporated into software that simulates the movements of the vehicle on planned paths across the terrain. The software in question is that of the Web Interface for Telescience (WITS), selected aspects of which have been described in a number of prior NASA Tech Briefs articles. To recapitulate: The WITS is a system of computer software that enables scientists, located at geographically dispersed computer terminals connected to the World Wide Web, to command instrumented robotic vehicles (rovers) during exploration of Mars and perhaps eventually of other planets. The WITS also has potential for adaptation to terrestrial use in telerobotics and other applications that involve computer-based remote monitoring, supervision, control, and planning.

  19. Research on Multi-Directional Pose Accuracy Variation to a Welding Robot

    NASA Astrophysics Data System (ADS)

    Vacarescu, V.; Lovasz, E. Ch.; Buciuman, C. F.

    Evaluation of functional characteristics of industrial robots is one aspect of their development. If one examines the many robotic applications, it is found that in most cases the performance characteristics involve aspects of positioning and orientation. Parameter analyzed in this paper refers precisely to this type of performance. In the robotics field, there are different methods and techniques in order to determine the performance characteristics of the industrial robots. In this paper the authors used a method for measuring and evaluating multi-directional pose accuracy variation performance for a welding robot, through 3D triangulation with two digital theodolite. For this purpose it uses a calibrated cube, mounted on the robot end—effector. The method allows the determination of the performances in concordance with the ISO 9283 recommendations and is validated of experimentally researches.

  20. A statistical multi-vertebrae shape+pose model for segmentation of CT images

    NASA Astrophysics Data System (ADS)

    Rasoulian, Abtin; Rohling, Robert N.; Abolmaesumi, Purang

    2013-03-01

    Segmentation of the spinal column from CT images is a pre-processing step for a range of image guided interventions. Current techniques focus on identification and separate segmentation of each vertebra. Recently, statistical multi-object shape models have been introduced to extract common statistical characteristics between several anatomies. These models are also used for segmentation purposes and are shown to be robust, accurate, and computationally tractable. In this paper, we reconstruct a statistical multi-vertebrae shape+pose model and propose a novel technique to register such a model to CT images. We validate our technique in terms of accuracy of the multi-vertebrae segmentation of CT images acquired from 16 subjects. The mean distance error achieved for all vertebrae is 1.17 mm with standard deviation of 0.38 mm.

  1. STS-40 crewmembers pose for onboard (in space) portrait on OV-102's middeck

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-40 crewmembers pose for onboard (in space) portrait on the middeck of Columbia, Orbiter Vehicle (OV) 102, with various university and military decals and insignias displayed on the port side wall behind them. In the front row (left to right) are Payload Specialist F. Drew Gaffney, Pilot Sidney M. Gutierrez, Mission Specialist (MS) M. Rhea Seddon, and MS James P. Bagian. Behind them (left to right) are Commander Bryan D. O'Connor, MS Tamara E. Jernigan, and Payload Specialist Millie Hughes-Fulford. The various decals include the University of California, United States Air Force (USAF) Academy Parachute Team, University of Tennessee, Air Force, Stanford University, Marines, Air Force Reserves (AFRES), and Colorado State University. The open airlock hatch and air revitalization system (ARS) duct appear on the left and the forward middeck lockers and the orbiter refrigerator freezer (ORF) on the right.

  2. STS-85 crew poses in the white room at LC 39A during TCDT

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The STS-85 flight crew poses in the white room at Launch Pad 39A during a break in Terminal Countdown Demonstration Test (TCDT) activities for that mission. They are (from left): Payload Commander N. Jan Davis; Payload Specialist Bjarni V. Tryggvason; Commander Curtis L. Brown, Jr.; Mission Specialist Stephen K. Robinson; Pilot Kent V. Rominger; and Mission Specialist Robert L. Curbeam, Jr. The primary payload aboard the Space Shuttle orbiter Discovery is the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-2 (CRISTA-SPAS-2). Other payloads on the 11-day mission include the Manipulator Flight Demonstration (MFD), and Technology Applications and Science-1 (TAS-1) and International Extreme Ultraviolet Hitchhiker-2 (IEH- 2) experiments.

  3. STS-105 and Expedition Three crews pose together for photo on Fixed Service Structure

    NASA Technical Reports Server (NTRS)

    2001-01-01

    KENNEDY SPACE CENTER, Fla. -- The STS-105 crew poses on the Fixed Service Structure at Launch Pad 39A. From left are Mission Specialist Patrick Forrester, Commander Scott Horowitz, Pilot Rick Sturckow and Mission Specialist Dan Barry. The STS-105 and Expedition Three crews are at Kennedy Space Center participating in a Terminal Countdown Demonstration Test, a dress rehearsal for launch. The activities include emergency egress training, a simulated launch countdown and familiarization with the payload. Mission STS-105 will be transporting the Expedition Three crew, several payloads and scientific experiments to the International Space Station aboard Space Shuttle Discovery. The Expedition Two crew members currently on the Station will return to Earth on Discovery. The mission is scheduled to launch no earlier than Aug. 9, 2001.

  4. Pose Measurement Performance of the Argon Relative Navigation Sensor Suite in Simulated Flight Conditions

    NASA Technical Reports Server (NTRS)

    Galante, Joseph M.; Eepoel, John Van; Strube, Matt; Gill, Nat; Gonzalez, Marcelo; Hyslop, Andrew; Patrick, Bryan

    2012-01-01

    Argon is a flight-ready sensor suite with two visual cameras, a flash LIDAR, an on- board flight computer, and associated electronics. Argon was designed to provide sensing capabilities for relative navigation during proximity, rendezvous, and docking operations between spacecraft. A rigorous ground test campaign assessed the performance capability of the Argon navigation suite to measure the relative pose of high-fidelity satellite mock-ups during a variety of simulated rendezvous and proximity maneuvers facilitated by robot manipulators in a variety of lighting conditions representative of the orbital environment. A brief description of the Argon suite and test setup are given as well as an analysis of the performance of the system in simulated proximity and rendezvous operations.

  5. Canadian federal support for climate change and health research compared with the risks posed.

    PubMed

    Ford, James D; Smith, Tanya R; Berrang-Ford, Lea

    2011-05-01

    For emerging public health risks such as climate change, the Canadian federal government has a mandate to provide information and resources to protect citizens' health. Research is a key component of this mandate and is essential if Canada is to moderate the health effects of a changing climate. We assessed whether federal support for climate change and health research is consistent with the risks posed. We audited projects receiving federal support between 1999 and 2009, representing an investment of Can$16 million in 105 projects. Although funding has increased in recent years, it remains inadequate, with negligible focus on vulnerable populations, limited research on adaptation, and volatility in funding allocations. A federal strategy to guide research support is overdue.

  6. The "mental feature" in mental illness: difficulties that this reality poses for diagnosis and classification.

    PubMed

    Casarotti, Humberto L

    2013-01-01

    Four points are considered in this article. In the first place, it is argued that the "settings" of psychiatric care express the need to respond to the degree of decrease in personal freedom of the patient. Then, the issue of how "the mental feature" of the mental pathology has been recognized and categorized since the 18th century is examined, pointing out the difficulties involved in considering the mental nature of the subject of psychiatry. In the third place, the issue of how current systems of diagnosis and classification are posed regarding this reality is briefly looked at. Finally, the characteristics of a working hypothesis that allows organizing consistent clinical facts providing a heuristic perspective are analyzed.

  7. Evaluation of DOCK 6 as a pose generation and database enrichment tool

    NASA Astrophysics Data System (ADS)

    Brozell, Scott R.; Mukherjee, Sudipto; Balius, Trent E.; Roe, Daniel R.; Case, David A.; Rizzo, Robert C.

    2012-06-01

    In conjunction with the recent American Chemical Society symposium titled "Docking and Scoring: A Review of Docking Programs" the performance of the DOCK6 program was evaluated through (1) pose reproduction and (2) database enrichment calculations on a common set of organizer-specified systems and datasets (ASTEX, DUD, WOMBAT). Representative baseline grid score results averaged over five docking runs yield a relatively high pose identification success rate of 72.5 % (symmetry corrected rmsd) and sampling rate of 91.9 % for the multi site ASTEX set (N = 147) using organizer-supplied structures. Numerous additional docking experiments showed that ligand starting conditions, symmetry, multiple binding sites, clustering, and receptor preparation protocols all affect success. Encouragingly, in some cases, use of more sophisticated scoring and sampling methods yielded results which were comparable (Amber score ligand movable protocol) or exceeded (LMOD score) analogous baseline grid-score results. The analysis highlights the potential benefit and challenges associated with including receptor flexibility and indicates that different scoring functions have system dependent strengths and weaknesses. Enrichment studies with the DUD database prepared using the SB2010 preparation protocol and native ligand pairings yielded individual area under the curve (AUC) values derived from receiver operating characteristic curve analysis ranging from 0.29 (bad enrichment) to 0.96 (good enrichment) with an average value of 0.60 (27/38 have AUC ≥ 0.5). Strong early enrichment was also observed in the critically important 1.0-2.0 % region. Somewhat surprisingly, an alternative receptor preparation protocol yielded comparable results. As expected, semi-random pairings yielded poorer enrichments, in particular, for unrelated receptors. Overall, the breadth and number of experiments performed provide a useful snapshot of current capabilities of DOCK6 as well as starting points to guide

  8. PT-VWD posing diagnostic and therapeutic challenges - small case series.

    PubMed

    Sánchez-Luceros, Analía; Woods, Adriana I; Bermejo, Emilse; Shukla, Shilpa; Acharya, Suchitra; Lavin, Michelle; Rydz, Natalia; Othman, Maha

    2016-11-07

    Despite the increased worldwide awareness, over the last decade, of the platelet-type von Willebrand Disease (PT-VWD), many uncertainties remain around this rare platelet bleeding disorder. This report aims to correctly identify and study the phenotype of new patients and highlights the diagnostic and therapeutic challenges this disease remains to pose. We describe four PT-VWD cases confirmed by genetic analysis in which either the diagnosis and/or the treatment posed challenge. We provide the details of the clinical presentation, laboratory analysis, and the treatment and the responses in each case. We show that in addition to type 2B VWD, PT-VWD can be misdiagnosed as idiopathic thrombocytopenic purpura, neonatal alloimmune thrombocytopenia, and unexplained gestational thrombocytopenia. The disease can be diagnosed as early as 1 year of age and with phenotypically normal parents. Bleeding in some patients can be managed successfully using Humate P and DDAVP combined with tranexamic acid with no significant thrombocytopenia. We provide for the first time an evidence of an efficient response to rFVIIa in PT-VWD. Anaphylactic reaction to VWF preparations may be related to PT-VWD and the development of HLA antibodies is not uncommon. Progressive thrombocytopenia with normal VWF levels can be seen with PT-VWD and the platelet count was normalized at 2.5 weeks postpartum in one case. We conclude that these studies represent a record of clinical observations/interventions that help improve diagnoses/management of PT-VWD, highlight the variations in age and clinical presentations, laboratory diagnostic approaches, the importance of genetic testing for accurate diagnosis and consideration of therapeutic alternatives.

  9. Assessment of the human health risks posed by exposure to chromium-contaminated soils

    SciTech Connect

    Sheehan, P.J.; Meyer, D.M.; Sauer, M.M.; Paustenbach, D.J. )

    1991-02-01

    Millions of tons of chromite-ore processing residue have been used as fill in various locations in northern New Jersey and elsewhere in the United States. The primary toxicants in the residue are trivalent chromium (Cr(III)) and hexavalent chromium (Cr(VI)). The hazard posed by Cr(III) is negligible due to its low acute and chronic toxicity. In contrast, Cr(VI) is a human carcinogen following inhalation of high concentrations. It can also cause allergic contact dermatitis. This evaluation addresses a residential site where the arithmetic mean (x) and geometric mean (gm) concentrations of Cr(III) in soil were 2879 and 1212 mg/kg (ppm). The mean concentrations of Cr(VI) were 180 and 4 mg/kg, respectively. The uptake (absorbed dose) of Cr(III) via soil ingestion, consumption of homegrown vegetables, and ingestion of inspired particles was determined. The uptake of Cr(VI) via dermal absorption from contact with surface soil and building wall surfaces, as well as inhalation, was also evaluated. The techniques used in this assessment are applicable for evaluating the human health risks posed by any residential site having contaminated soil. The potential for both sensitized and unsensitized persons to develop allergic contact dermatitis due to exposure to soil contaminated at these levels was found to be negligible. The estimated average daily dose (ADD) via ingestion and dermal absorption for the maximally exposed individual (MEI) was about 1500- and 40-fold below the EPA reference dose (RfD) for Cr(III) and Cr(VI), respectively. It was shown that for residential sites, the most important route of exposure to Cr(III) was incidental soil ingestion. Although not relevant to these sites specifically, if garden vegetables could be successfully grown in these soils, then they would probably be the predominant source of uptake of Cr(III). 163 refs.

  10. Dependence of ski jump length on the skier's body pose at the beginning of take-off.

    PubMed

    Zanevskyy, Ihor; Banakh, Volodymyr

    2010-01-01

    A kinematical model of the ski jumper's body pose at the beginning of take-off was proposed. A method of measuring skier's body coordinates based on the results of video recordings and office information technologies was created. Kinematical parameters of the skier's body pose at the beginning of take-off were determined using sport competition results of 33 ski jumpers. Five parameters of the pose which show statistically significant correlation (р < 0.03) with the jump length were determined. A part of variation of the model parameters in the total variation of the jump length is almost equal to 53%, and relative correlation is strong and significant (p < 0.005). Recommendations regarding optimization of the body pose at the beginning of take-off were formulated.

  11. Machine-learning scoring functions for identifying native poses of ligands docked to known and novel proteins

    PubMed Central

    2015-01-01

    Background Molecular docking is a widely-employed method in structure-based drug design. An essential component of molecular docking programs is a scoring function (SF) that can be used to identify the most stable binding pose of a ligand, when bound to a receptor protein, from among a large set of candidate poses. Despite intense efforts in developing conventional SFs, which are either force-field based, knowledge-based, or empirical, their limited docking power (or ability to successfully identify the correct pose) has been a major impediment to cost-effective drug discovery. Therefore, in this work, we explore a range of novel SFs employing different machine-learning (ML) approaches in conjunction with physicochemical and geometrical features characterizing protein-ligand complexes to predict the native or near-native pose of a ligand docked to a receptor protein's binding site. We assess the docking accuracies of these new ML SFs as well as those of conventional SFs in the context of the 2007 PDBbind benchmark dataset on both diverse and homogeneous (protein-family-specific) test sets. Further, we perform a systematic analysis of the performance of the proposed SFs in identifying native poses of ligands that are docked to novel protein targets. Results and conclusion We find that the best performing ML SF has a success rate of 80% in identifying poses that are within 1 Å root-mean-square deviation from the native poses of 65 different protein families. This is in comparison to a success rate of only 70% achieved by the best conventional SF, ASP, employed in the commercial docking software GOLD. In addition, the proposed ML SFs perform better on novel proteins that they were never trained on before. We also observed steady gains in the performance of these scoring functions as the training set size and number of features were increased by considering more protein-ligand complexes and/or more computationally-generated poses for each complex. PMID:25916860

  12. Face Recognition across Varying Poses in 7- and 9-Month-Old Infants: The Role of Facial Expression

    ERIC Educational Resources Information Center

    Gross, Cornelia; Schwarzer, Gudrun

    2010-01-01

    Three studies were conducted to determine whether 7- and 9-month-old infants generalize face identity to a novel pose of the same face when only internal face sections with and without an emotional expression were presented. In Study 1, 7- and 9-month-old infants were habituated to a full frontal or three-quarter pose of a face with neutral facial…

  13. Head Pose Estimation on Top of Haar-Like Face Detection: A Study Using the Kinect Sensor

    PubMed Central

    Saeed, Anwar; Al-Hamadi, Ayoub; Ghoneim, Ahmed

    2015-01-01

    Head pose estimation is a crucial initial task for human face analysis, which is employed in several computer vision systems, such as: facial expression recognition, head gesture recognition, yawn detection, etc. In this work, we propose a frame-based approach to estimate the head pose on top of the Viola and Jones (VJ) Haar-like face detector. Several appearance and depth-based feature types are employed for the pose estimation, where comparisons between them in terms of accuracy and speed are presented. It is clearly shown through this work that using the depth data, we improve the accuracy of the head pose estimation. Additionally, we can spot positive detections, faces in profile views detected by the frontal model, that are wrongly cropped due to background disturbances. We introduce a new depth-based feature descriptor that provides competitive estimation results with a lower computation time. Evaluation on a benchmark Kinect database shows that the histogram of oriented gradients and the developed depth-based features are more distinctive for the head pose estimation, where they compare favorably to the current state-of-the-art approaches. Using a concatenation of the aforementioned feature types, we achieved a head pose estimation with average errors not exceeding 5.1∘,4.6∘,4.2∘ for pitch, yaw and roll angles, respectively. PMID:26343651

  14. Own- and other-race face identity recognition in children: the effects of pose and feature composition.

    PubMed

    Anzures, Gizelle; Kelly, David J; Pascalis, Olivier; Quinn, Paul C; Slater, Alan M; de Viviés, Xavier; Lee, Kang

    2014-02-01

    We used a matching-to-sample task and manipulated facial pose and feature composition to examine the other-race effect (ORE) in face identity recognition between 5 and 10 years of age. Overall, the present findings provide a genuine measure of own- and other-race face identity recognition in children that is independent of photographic and image processing. The current study also confirms the presence of an ORE in children as young as 5 years of age using a recognition paradigm that is sensitive to their developing cognitive abilities. In addition, the present findings show that with age, increasing experience with familiar classes of own-race faces and further lack of experience with unfamiliar classes of other-race faces serves to maintain the ORE between 5 and 10 years of age rather than exacerbate the effect. All age groups also showed a differential effect of stimulus facial pose in their recognition of the internal regions of own- and other-race faces. Own-race inner faces were remembered best when three-quarter poses were used during familiarization and frontal poses were used during the recognition test. In contrast, other-race inner faces were remembered best when frontal poses were used during familiarization and three-quarter poses were used during the recognition test. Thus, children encode and/or retrieve own- and other-race faces from memory in qualitatively different ways.

  15. Head Pose Estimation on Top of Haar-Like Face Detection: A Study Using the Kinect Sensor.

    PubMed

    Saeed, Anwar; Al-Hamadi, Ayoub; Ghoneim, Ahmed

    2015-08-26

    Head pose estimation is a crucial initial task for human face analysis, which is employed in several computer vision systems, such as: facial expression recognition, head gesture recognition, yawn detection, etc. In this work, we propose a frame-based approach to estimate the head pose on top of the Viola and Jones (VJ) Haar-like face detector. Several appearance and depth-based feature types are employed for the pose estimation, where comparisons between them in terms of accuracy and speed are presented. It is clearly shown through this work that using the depth data, we improve the accuracy of the head pose estimation. Additionally, we can spot positive detections, faces in profile views detected by the frontal model, that are wrongly cropped due to background disturbances. We introduce a new depth-based feature descriptor that provides competitive estimation results with a lower computation time. Evaluation on a benchmark Kinect database shows that the histogram of oriented gradients and the developed depth-based features are more distinctive for the head pose estimation, where they compare favorably to the current state-of-the-art approaches. Using a concatenation of the aforementioned feature types, we achieved a head pose estimation with average errors not exceeding 5:1; 4:6; 4:2 for pitch, yaw and roll angles, respectively.

  16. Precise 3D Lug Pose Detection Sensor for Automatic Robot Welding Using a Structured-Light Vision System

    PubMed Central

    Park, Jae Byung; Lee, Seung Hun; Lee, Il Jae

    2009-01-01

    In this study, we propose a precise 3D lug pose detection sensor for automatic robot welding of a lug to a huge steel plate used in shipbuilding, where the lug is a handle to carry the huge steel plate. The proposed sensor consists of a camera and four laser line diodes, and its design parameters are determined by analyzing its detectable range and resolution. For the lug pose acquisition, four laser lines are projected on both lug and plate, and the projected lines are detected by the camera. For robust detection of the projected lines against the illumination change, the vertical threshold, thinning, Hough transform and separated Hough transform algorithms are successively applied to the camera image. The lug pose acquisition is carried out by two stages: the top view alignment and the side view alignment. The top view alignment is to detect the coarse lug pose relatively far from the lug, and the side view alignment is to detect the fine lug pose close to the lug. After the top view alignment, the robot is controlled to move close to the side of the lug for the side view alignment. By this way, the precise 3D lug pose can be obtained. Finally, experiments with the sensor prototype are carried out to verify the feasibility and effectiveness of the proposed sensor. PMID:22400007

  17. Deinstitutionalization in Greece: Ethical problems.

    PubMed

    Ploumpidis, D; Garanis-Papadatos, T; Economou, M

    2008-10-01

    The following paper is based on a Concerted Action which focused on the "Ethical aspects of deistinstutionalisation in mental health care" in 2001. It investigates the development and the ethical dilemmas posed by deinstitutionalization in Greece. This movement has recently undergone a very active phase but the transition from the traditional model of psychiatric care to the community based system unavoidably creates many ethical problems related to the professionals' attitude towards individual liberties, dignity and other fundamental rights of mentally ill persons. These problems exist not only in the level of the therapist-patient relationship but in the level of policy making as well as its implementation. Moreover, the paper deals with specific ethical problems such as stigmatisation and isolation in the community context, as well as the role of the family.

  18. An elliptic singularly perturbed problem with two parameters I

    NASA Astrophysics Data System (ADS)

    Teofanov, Lj.; Roos, H. G.

    2007-09-01

    In this paper we consider a singularly perturbed elliptic problem with two small parameters posed on the unit square. Its solution may have exponential, parabolic and corner layers. We give a decomposition of the solution into regular and layer components and derive pointwise bounds on the components and their derivatives. The estimates are obtained by the analysis of appropriate problems on unbounded domains.

  19. Childbirth Problems

    MedlinePlus

    While childbirth usually goes well, complications can happen. They can cause a risk to the mother, baby, or both. Possible complications include Preterm (premature) labor, when labor starts before 37 completed weeks of pregnancy Problems with the umbilical cord Problems with ...

  20. Speech Problems

    MedlinePlus

    ... and the respiratory system . The ability to understand language and produce speech is coordinated by the brain. So a person with brain damage from an accident, stroke, or birth defect may have speech and language problems. Some people with speech problems, particularly articulation ...

  1. Popular Problems

    ERIC Educational Resources Information Center

    Skovhus, Randi Boelskifte; Thomsen, Rie

    2017-01-01

    This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the "What's the problem represented to be" (WPR) approach. Forty-nine…

  2. Parking Problem

    ERIC Educational Resources Information Center

    Foster, Colin

    2012-01-01

    This is the story of a real problem, not a problem that is contrived, or invented for the convenience of the appropriate planning tool. This activity by a group of students, defined simply as "8FN", might be likened to an "end of term concert". If you just happened to be a delegate at the ATM Conference 2003 you might remember…

  3. Problem-Based Learning in Language Instruction: A Constructivist Model. Eric Digest.

    ERIC Educational Resources Information Center

    Abdullah, Mardziah Hayati

    This Digest discusses Problem-Based Learning (PBL), a method developed by H.S. Barrows (1986), and originally created to prepare medical students for real-world problems by letting them solve medical problems based on real cases. The Digest contends that PBL can situate language learning in the real world by posing problems like those found in…

  4. What threat do turbidity currents and submarine landslides pose to submarine telecommunications cable infrastructure?

    NASA Astrophysics Data System (ADS)

    Clare, Michael; Pope, Edward; Talling, Peter; Hunt, James; Carter, Lionel

    2016-04-01

    The global economy relies on uninterrupted usage of a network of telecommunication cables on the seafloor. These submarine cables carry ~99% of all trans-oceanic digital data and voice communications traffic worldwide, as they have far greater bandwidth than satellites. Over 9 million SWIFT banks transfers alone were made using these cables in 2004, totalling 7.4 trillion of transactions per day between 208 countries, which grew to 15 million SWIFT bank transactions last year. We outline the challenge of why, how often, and where seafloor cables are broken by natural causes; primarily subsea landslides and sediment flows (turbidity currents and also debris flows and hyperpycnal flows). These slides and flows can be very destructive. As an example, a sediment flow in 1929 travelled up to 19 m/s and broke 11 cables in the NE Atlantic, running out for ~800 km to the abyssal ocean. The 2006 Pingtung earthquake triggered a sediment flow that broke 22 cables offshore Taiwan over a distance of 450 km. Here, we present initial results from the first statistical analysis of a global database of cable breaks and causes. We first investigate the controls on frequency of submarine cable breaks in different environmental and geological settings worldwide. We assess which types of earthquake pose a significant threat to submarine cable networks. Meteorological events, such as hurricanes and typhoons, pose a significant threat to submarine cable networks, so we also discuss the potential impacts of future climate change on the frequency of such hazards. We then go on to ask what are the physical impacts of submarine sediment flows on submerged cables? A striking observation from past cable breaks is sometimes cables remain unbroken, whilst adjacent cables are severed (and record powerful flows travelling at up to 6 m/s). Why are some cables broken, but neighbouring cables remain intact? We provide some explanations for this question, and outline the need for future in

  5. Regularization for Atmospheric Temperature Retrieval Problems

    NASA Technical Reports Server (NTRS)

    Velez-Reyes, Miguel; Galarza-Galarza, Ruben

    1997-01-01

    Passive remote sensing of the atmosphere is used to determine the atmospheric state. A radiometer measures microwave emissions from earth's atmosphere and surface. The radiance measured by the radiometer is proportional to the brightness temperature. This brightness temperature can be used to estimate atmospheric parameters such as temperature and water vapor content. These quantities are of primary importance for different applications in meteorology, oceanography, and geophysical sciences. Depending on the range in the electromagnetic spectrum being measured by the radiometer and the atmospheric quantities to be estimated, the retrieval or inverse problem of determining atmospheric parameters from brightness temperature might be linear or nonlinear. In most applications, the retrieval problem requires the inversion of a Fredholm integral equation of the first kind making this an ill-posed problem. The numerical solution of the retrieval problem requires the transformation of the continuous problem into a discrete problem. The ill-posedness of the continuous problem translates into ill-conditioning or ill-posedness of the discrete problem. Regularization methods are used to convert the ill-posed problem into a well-posed one. In this paper, we present some results of our work in applying different regularization techniques to atmospheric temperature retrievals using brightness temperatures measured with the SSM/T-1 sensor. Simulation results are presented which show the potential of these techniques to improve temperature retrievals. In particular, no statistical assumptions are needed and the algorithms were capable of correctly estimating the temperature profile corner at the tropopause independent of the initial guess.

  6. Hand Pose Estimation by Fusion of Inertial and Magnetic Sensing Aided by a Permanent Magnet.

    PubMed

    Kortier, Henk G; Antonsson, Jacob; Schepers, H Martin; Gustafsson, Fredrik; Veltink, Peter H

    2015-09-01

    Tracking human body motions using inertial sensors has become a well-accepted method in ambulatory applications since the subject is not confined to a lab-bounded volume. However, a major drawback is the inability to estimate relative body positions over time because inertial sensor information only allows position tracking through strapdown integration, but does not provide any information about relative positions. In addition, strapdown integration inherently results in drift of the estimated position over time. We propose a novel method in which a permanent magnet combined with 3-D magnetometers and 3-D inertial sensors are used to estimate the global trunk orientation and relative pose of the hand with respect to the trunk. An Extended Kalman Filter is presented to fuse estimates obtained from inertial sensors with magnetic updates such that the position and orientation between the human hand and trunk as well as the global trunk orientation can be estimated robustly. This has been demonstrated in multiple experiments in which various hand tasks were performed. The most complex task in which simultaneous movements of both trunk and hand were performed resulted in an average rms position difference with an optical reference system of 19.7±2.2 mm whereas the relative trunk-hand and global trunk orientation error was 2.3±0.9 and 8.6±8.7 deg respectively.

  7. Comparison of different methods for gender estimation from face image of various poses

    NASA Astrophysics Data System (ADS)

    Ishii, Yohei; Hongo, Hitoshi; Niwa, Yoshinori; Yamamoto, Kazuhiko

    2003-04-01

    Recently, gender estimation from face images has been studied for frontal facial images. However, it is difficult to obtain such facial images constantly in the case of application systems for security, surveillance and marketing research. In order to build such systems, a method is required to estimate gender from the image of various facial poses. In this paper, three different classifiers are compared in appearance-based gender estimation, which use four directional features (FDF). The classifiers are linear discriminant analysis (LDA), Support Vector Machines (SVMs) and Sparse Network of Winnows (SNoW). Face images used for experiments were obtained from 35 viewpoints. The direction of viewpoints varied +/-45 degrees horizontally, +/-30 degrees vertically at 15 degree intervals respectively. Although LDA showed the best performance for frontal facial images, SVM with Gaussian kernel was found the best performance (86.0%) for the facial images of 35 viewpoints. It is considered that SVM with Gaussian kernel is robust to changes in viewpoint when estimating gender from these results. Furthermore, the estimation rate was quite close to the average estimation rate at 35 viewpoints respectively. It is supposed that the methods are reasonable to estimate gender within the range of experimented viewpoints by learning face images from multiple directions by one class.

  8. Wild buckwheat is unlikely to pose a risk to buckwheat-allergic individuals.

    PubMed

    Nordlee, Julie A; Panda, Rakhi; Baumert, Joseph L; Goodman, Richard E; Taylor, Steve L

    2011-10-01

    Buckwheat (Fagopyrum esculentum) is a commonly allergenic food especially in Asia where buckwheat is more commonly consumed. Wild buckwheat (Polygonum convolvulus, recently changed to Fallopia convolvulus) is an annual weed prevalent in grain-growing areas of the United States. Wild buckwheat is not closely related to edible buckwheat although the seeds do have some physical resemblance. A large shipment of wheat into Japan was halted by the discovery of the adventitious presence of wild buckwheat seeds over possible concerns for buckwheat-allergic consumers. However, IgE-binding was not observed to an extract of wild buckwheat using sera from 3 buckwheat-allergic individuals either by radio-allergosorbent test inhibition or by immunoblotting after protein separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Furthermore, the extract of wild buckwheat was not detected in a buckwheat enzyme-linked immunosorbent assay developed with antisera against common buckwheat. Thus, wild buckwheat is highly unlikely to pose any risk to buckwheat-allergic individuals. The common names of plants should not be a factor in the risk assessment for possible cross-allergenicity.

  9. Single trial detection of hand poses in human ECoG using CSP based feature extraction.

    PubMed

    Kapeller, C; Schneider, C; Kamada, K; Ogawa, H; Kunii, N; Ortner, R; Pruckl, R; Guger, C

    2014-01-01

    Decoding brain activity of corresponding highlevel tasks may lead to an independent and intuitively controlled Brain-Computer Interface (BCI). Most of today's BCI research focuses on analyzing the electroencephalogram (EEG) which provides only limited spatial and temporal resolution. Derived electrocorticographic (ECoG) signals allow the investigation of spatially highly focused task-related activation within the high-gamma frequency band, making the discrimination of individual finger movements or complex grasping tasks possible. Common spatial patterns (CSP) are commonly used for BCI systems and provide a powerful tool for feature optimization and dimensionality reduction. This work focused on the discrimination of (i) three complex hand movements, as well as (ii) hand movement and idle state. Two subjects S1 and S2 performed single `open', `peace' and `fist' hand poses in multiple trials. Signals in the high-gamma frequency range between 100 and 500 Hz were spatially filtered based on a CSP algorithm for (i) and (ii). Additionally, a manual feature selection approach was tested for (i). A multi-class linear discriminant analysis (LDA) showed for (i) an error rate of 13.89 % / 7.22 % and 18.42 % / 1.17 % for S1 and S2 using manually / CSP selected features, where for (ii) a two class LDA lead to a classification error of 13.39 % and 2.33 % for S1 and S2, respectively.

  10. STS-95 Payload Specialist Glenn and his wife pose before their return flight to JSC

    NASA Technical Reports Server (NTRS)

    1998-01-01

    At the Skid Strip at Cape Canaveral Air Station, STS-95 Payload Specialist John H. Glenn Jr., a senator from Ohio and one of the original seven Project Mercury astronauts, poses with his wife Annie before their return flight to the Johnson Space Center in Houston, Texas. The STS-95 mission ended with landing at Kennedy Space Center's Shuttle Landing Facility at 12:04 p.m. EST on Nov. 7. The STS-95 crew also includes Mission Commander Curtis L. Brown Jr.; Pilot Steven W. Lindsey; Mission Specialist Scott E. Parazynski; Mission Specialist Stephen K. Robinson; Mission Specialist Pedro Duque, with the European Space Agency (ESA); and Payload Specialist Chiaki Mukai, with the National Space Development Agency of Japan (NASDA). The mission included research payloads such as the Spartan-201 solar-observing deployable spacecraft, the Hubble Space Telescope Orbital Systems Test Platform, the International Extreme Ultraviolet Hitchhiker, as well as a SPACEHAB single module with experiments on space flight and the aging process.

  11. The STS-95 crew poses with a Mercury capsule model before returning to JSC

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Before returning to the Johnson Space Center in Houston, Texas, members of the STS-95 crew pose with a model of a Mercury capsule following a media briefing at the Kennedy Space Center Press Site Auditorium . From left to right are Payload Specialist Chiaki Mukai, with the National Space Development Agency of Japan (NASDA); Pilot Steven W. Lindsey; Mission Commander Curtis L. Brown Jr.; Friendship 7; Payload Specialist John H. Glenn Jr., a senator from Ohio and one of the original seven Project Mercury astronauts; Mission Specialist Scott E. Parazynski; and Mission Specialist Pedro Duque, with the European Space Agency (ESA). Also on the crew is Mission Specialist and Payload Commander Stephen K. Robinson (not shown). The STS-95 mission ended with landing at Kennedy Space Center's Shuttle Landing Facility at 12:04 p.m. EST on Nov. 7. The mission included research payloads such as the Spartan-201 solar-observing deployable spacecraft, the Hubble Space Telescope Orbital Systems Test Platform, the International Extreme Ultraviolet Hitchhiker, as well as a SPACEHAB single module with experiments on space flight and the aging process.

  12. Do biological medicinal products pose a risk to the environment?: a current view on ecopharmacovigilance.

    PubMed

    Kühler, Thomas C; Andersson, Mikael; Carlin, Gunnar; Johnsson, Ann; Akerblom, Lennart

    2009-01-01

    The occurrence of active pharmaceutical substances in the environment is of growing concern. The vast majority of the compounds in question are of low molecular weight, intended for oral use and designed to tolerate, for example, the digestive enzymes in the upper alimentary tract, the harsh milieus found in the acidic stomach, or the microbe rich intestine. Accordingly, these xenobiotic compounds may, due to their inherent biological activity, constitute a risk to the environment. Biological medicinal products, for example recombinant human insulin or monoclonal antibodies, however, are different. They are primarily made up of oligomers or polymers of amino acids, sugars or nucleotides and are thus readily metabolized. They are therefore generally not considered to pose any risk to the environment. Certain classes of biological medicinal products, however, are associated with specific safety issues. Genetically modified organisms as vectors in vaccines or in gene therapy products have attracted much attention in this regard. Issues include the degree of attenuation of the live recombinant vaccine, replication restrictions of the vaccine vector, alteration of the host and tissue tropism of the vector, the possibility of reversion to virulence, and risk to the ecosystem. In this review we discuss the fate and the potential environmental impact of biological medicinal products following clinical use from an ecopharmacovigilance point of view, and review relevant policy documents and regulatory statements.

  13. Hazard to man and the environment posed by the use of urban waste compost: a review.

    PubMed

    Déportes, I; Benoit-Guyod, J L; Zmirou, D

    1995-11-30

    This review presents the current state of knowledge on the relationship between the environment and the use of municipal waste compost in terms of health risk assessment. The hazards stem from chemical and microbiological agents whose nature and magnitude depend heavily on the degree of sorting and on the composting methods. Three main routes of exposure can be determined and are quantified in the literature: (i) The ingestion of soil/compost mixtures by children, mostly in cases of pica, can be a threat because of the amount of lead, chromium, cadmium, PCDD/F and fecal streptococci that can be absorbed. (ii) Though concern about contamination through the food chain is weak when compost is used in agriculture, some authors anticipate accumulation of pollutants after several years of disposal, which might lead to future hazards. (iii) Exposure is also associated with atmospheric dispersion of compost organic dust that convey microorganisms and toxicants. Data on hazard posed by organic dust from municipal composts to the farmer or the private user is scarce. To date, microorganisms are only measured at composting plants, thus raising the issue of extrapolation to environmental situations. Lung damage and allergies may occur because of organic dust, Gram negative bacteria, actinomycetes and fungi. Further research is needed on the risk related to inhalation of chemical compounds.

  14. Vision-Based Pose Estimation for Robot-Mediated Hand Telerehabilitation

    PubMed Central

    Airò Farulla, Giuseppe; Pianu, Daniele; Cempini, Marco; Cortese, Mario; Russo, Ludovico O.; Indaco, Marco; Nerino, Roberto; Chimienti, Antonio; Oddo, Calogero M.; Vitiello, Nicola

    2016-01-01

    Vision-based Pose Estimation (VPE) represents a non-invasive solution to allow a smooth and natural interaction between a human user and a robotic system, without requiring complex calibration procedures. Moreover, VPE interfaces are gaining momentum as they are highly intuitive, such that they can be used from untrained personnel (e.g., a generic caregiver) even in delicate tasks as rehabilitation exercises. In this paper, we present a novel master–slave setup for hand telerehabilitation with an intuitive and simple interface for remote control of a wearable hand exoskeleton, named HX. While performing rehabilitative exercises, the master unit evaluates the 3D position of a human operator’s hand joints in real-time using only a RGB-D camera, and commands remotely the slave exoskeleton. Within the slave unit, the exoskeleton replicates hand movements and an external grip sensor records interaction forces, that are fed back to the operator-therapist, allowing a direct real-time assessment of the rehabilitative task. Experimental data collected with an operator and six volunteers are provided to show the feasibility of the proposed system and its performances. The results demonstrate that, leveraging on our system, the operator was able to directly control volunteers’ hands movements. PMID:26861333

  15. Distributed observers for pose estimation in the presence of inertial sensory soft faults.

    PubMed

    Sadeghzadeh-Nokhodberiz, Nargess; Poshtan, Javad; Wagner, Achim; Nordheimer, Eugen; Badreddin, Essameddin

    2014-07-01

    Distributed Particle-Kalman Filter based observers are designed in this paper for inertial sensors (gyroscope and accelerometer) soft faults (biases and drifts) and rigid body pose estimation. The observers fuse inertial sensors with Photogrammetric camera. Linear and angular accelerations as unknown inputs of velocity and attitude rate dynamics, respectively, along with sensory biases and drifts are modeled and augmented to the moving body state parameters. To reduce the complexity of the high dimensional and nonlinear model, the graph theoretic tearing technique (structural decomposition) is employed to decompose the system to smaller observable subsystems. Separate interacting observers are designed for the subsystems which are interacted through well-defined interfaces. Kalman Filters are employed for linear ones and a Modified Particle Filter for a nonlinear non-Gaussian subsystem which includes imperfect attitude rate dynamics is proposed. The main idea behind the proposed Modified Particle Filtering approach is to engage both system and measurement models in the particle generation process. Experimental results based on data from a 3D MEMS IMU and a 3D camera system are used to demonstrate the efficiency of the method.

  16. STS-99 crew pose for a group photo at SLF after their arrival for launch

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The STS-99 crew pose for a photograph after their arrival at the Shuttle Landing Facility to prepare for launch. From left are Pilot Dominic Gorie, Mission Specialist Janice Voss (Ph.D.), Commander Kevin Kregel, and Mission Specialists Janet Lynn Kavandi (Ph.D.), Gerhard Thiele (Ph.D.) and Mamoru Mohri (Ph.D.). Thiele is with the European Space Agency and Mohri is with the National Space Development Agency (NASDA) of Japan. Behind them are the T-38 jets in which they arrived, and the mate/demate device. Over the next few days, the crew will review mission procedures, conduct test flights in the Shuttle Training Aircraft and undergo routine preflight medical exams. STS-99 is the Shuttle Radar Topography Mission, which will chart a new course, using two antennae and a 200-foot-long section of space station- derived mast protruding from the payload bay to produce unrivaled 3-D images of the Earth's surface. The result of the Shuttle Radar Topography Mission could be close to 1 trillion measurements of the Earth's topography. Besides contributing to the production of better maps, these measurements could lead to improved water drainage modeling, more realistic flight simulators, better locations for cell phone towers, and enhanced navigation safety. Launch of Endeavour is scheduled for Jan. 31 at 12:47 p.m. EST.

  17. Risks posed by trace organic contaminants in coastal sediments in the Pearl River Delta, China.

    PubMed

    Fung, C N; Zheng, G J; Connell, D W; Zhang, X; Wong, H L; Giesy, J P; Fang, Z; Lam, P K S

    2005-10-01

    Local marine environments in China's Pearl River Delta (PRD), the most rapidly developing region in one of the world's fastest growing economies, have been experiencing significant environmental stress during the past decades. This investigation was conducted to determine the status and trends of persistence organic pollutants (POPs) such as polycyclic aromatic hydrocarbons (PAHs), petroleum hydrocarbons (PHCs), polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides and dioxin-related compounds in marine sediments collected from sixteen coastal stations in the Pearl River Delta (PRD) in March 2003. Elevated concentrations of PAHs (94-4300 ng/g), PCBs (6.0-290 ng/g), PHCs (14-150 microg/g), and DDTs (1.4-600 ng/g) were detected in sediment samples. In addition, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-like activities in the sediment samples were estimated to range from 0.3 to 440 pg TCDD-EQ/g. Sediments collected from Xiashan contained the greatest concentrations of trace organic contaminations amongst all the sampling stations in the present study. The degree of trace organic contamination was, in general, more severe at stations situated along the west shores of the PRD than their counterparts in the east. A preliminary assessment was performed to examine the probable risks to the marine ecosystem due to POPs. The results showed that OC pesticide contamination in the PRD was particularly serious and might pose a threat to the health of the marine inhabitants.

  18. Autonomous proximity operations using machine vision for trajectory control and pose estimation

    NASA Technical Reports Server (NTRS)

    Cleghorn, Timothy F.; Sternberg, Stanley R.

    1991-01-01

    A machine vision algorithm was developed which permits guidance control to be maintained during autonomous proximity operations. At present this algorithm exists as a simulation, running upon an 80386 based personal computer, using a ModelMATE CAD package to render the target vehicle. However, the algorithm is sufficiently simple, so that following off-line training on a known target vehicle, it should run in real time with existing vision hardware. The basis of the algorithm is a sequence of single camera images of the target vehicle, upon which radial transforms were performed. Selected points of the resulting radial signatures are fed through a decision tree, to determine whether the signature matches that of the known reference signatures for a particular view of the target. Based upon recognized scenes, the position of the maneuvering vehicle with respect to the target vehicles can be calculated, and adjustments made in the former's trajectory. In addition, the pose and spin rates of the target satellite can be estimated using this method.

  19. Pose and motion recovery from feature correspondences and a digital terrain map.

    PubMed

    Lerner, Ronen; Rivlin, Ehud; Rotstein, Héctor P

    2006-09-01

    A novel algorithm for pose and motion estimation using corresponding features and a Digital Terrain Map is proposed. Using a Digital Terrain (or Digital Elevation) Map (DTM/DEM) as a global reference enables the elimination of the ambiguity present in vision-based algorithms for motion recovery. As a consequence, the absolute position and orientation of a camera can be recovered with respect to the external reference frame. In order to do this, the DTM is used to formulate a constraint between corresponding features in two consecutive frames. Explicit reconstruction of the 3D world is not required. When considering a number of feature points, the resulting constraints can be solved using nonlinear optimization in terms of position, orientation, and motion. Such a procedure requires an initial guess of these parameters, which can be obtained from dead-reckoning or any other source. The feasibility of the algorithm is established through extensive experimentation. Performance is compared with a state-of-the-art alternative algorithm, which intermediately reconstructs the 3D structure and then registers it to the DTM. A clear advantage for the novel algorithm is demonstrated in variety of scenarios.

  20. Global Climate Change and the Unique Challenges Posed by the Transportation Sector

    SciTech Connect

    Dooley, J.J.; Geffen, C.A.; Edmonds, J.A.

    2002-08-26

    Addressing the challenges posed by global climate change will eventually require the active participation of all industrial sectors and consumers on the planet. To date, however, most efforts to address climate change have focused on only a few sectors of the economy (e.g., refineries and fossil-fired electric power plants) and a handful of large industrialized nations. While useful as a starting point, these efforts must be expanded to include other sectors of the economy and other nations. The transportation sector presents some unique challenges, with its nearly exclusive dependence on petroleum based products as a fuel source coupled with internal combustion engines as the prime mover. Reducing carbon emissions from transportation systems is unlikely to be solely accomplished by traditional climate mitigation policies that place a price on carbon. Our research shows that price signals alone are unlikely to fundamentally alter the demand for energy services or to transform the way energy services are provided in the transportation sector. We believe that a technological revolution will be necessary to accomplish the significant reduction of greenhouse gas emissions from the transportation sector.

  1. Surety of the nation`s critical infrastructures: The challenge restructuring poses to the telecommunications sector

    SciTech Connect

    Cox, R.; Drennen, T.E.; Gilliom, L.; Harris, D.L.; Kunsman, D.M.; Skroch, M.J.

    1998-04-01

    The telecommunications sector plays a pivotal role in the system of increasingly connected and interdependent networks that make up national infrastructure. An assessment of the probable structure and function of the bit-moving industry in the twenty-first century must include issues associated with the surety of telecommunications. The term surety, as used here, means confidence in the acceptable behavior of a system in both intended and unintended circumstances. This paper outlines various engineering approaches to surety in systems, generally, and in the telecommunications infrastructure, specifically. It uses the experience and expectations of the telecommunications system of the US as an example of the global challenges. The paper examines the principal factors underlying the change to more distributed systems in this sector, assesses surety issues associated with these changes, and suggests several possible strategies for mitigation. It also studies the ramifications of what could happen if this sector became a target for those seeking to compromise a nation`s security and economic well being. Experts in this area generally agree that the U. S. telecommunications sector will eventually respond in a way that meets market demands for surety. Questions remain open, however, about confidence in the telecommunications sector and the nation`s infrastructure during unintended circumstances--such as those posed by information warfare or by cascading software failures. Resolution of these questions is complicated by the lack of clear accountability of the private and the public sectors for the surety of telecommunications.

  2. The interconnected and cross-border nature of risks posed by infectious diseases

    PubMed Central

    Suk, Jonathan E.; Van Cangh, Thomas; Beauté, Julien; Bartels, Cornelius; Tsolova, Svetla; Pharris, Anastasia; Ciotti, Massimo; Semenza, Jan C.

    2014-01-01

    Infectious diseases can constitute public health emergencies of international concern when a pathogen arises, acquires new characteristics, or is deliberately released, leading to the potential for loss of human lives as well as societal disruption. A wide range of risk drivers are now known to lead to and/or exacerbate the emergence and spread of infectious disease, including global trade and travel, the overuse of antibiotics, intensive agriculture, climate change, high population densities, and inadequate infrastructures, such as water treatment facilities. Where multiple risk drivers interact, the potential impact of a disease outbreak is amplified. The varying temporal and geographic frequency with which infectious disease events occur adds yet another layer of complexity to the issue. Mitigating the emergence and spread of infectious disease necessitates mapping and prioritising the interdependencies between public health and other sectors. Conversely, during an international public health emergency, significant disruption occurs not only to healthcare systems but also to a potentially wide range of sectors, including trade, tourism, energy, civil protection, transport, agriculture, and so on. At the same time, dealing with a disease outbreak may require a range of critical sectors for support. There is a need to move beyond narrow models of risk to better account for the interdependencies between health and other sectors so as to be able to better mitigate and respond to the risks posed by emerging infectious disease. PMID:25308818

  3. Latent-Class Hough Forests for 6 DoF Object Pose Estimation.

    PubMed

    Kouskouridas, Rigas; Tejani, Alykhan; Doumanoglou, Andreas; Tang, Danhang; Kim, Tae-Kyun

    2017-02-07

    In this paper we present Latent-Class Hough Forests, a method for object detection and 6 DoF pose estimation in heavily cluttered and occluded scenarios. We adapt a state of the art template matching feature into a scale-invariant patch descriptor and integrate it into a regression forest using a novel template-based split function. We train with positive samples only and we treat class distributions at the leaf nodes as latent variables. During testing we infer by iteratively updating these distributions, providing accurate estimation of background clutter and foreground occlusions and, thus, better detection rate. Furthermore, as a by-product, our Latent- Class Hough Forests can provide accurate occlusion aware segmentation masks, even in the multi-instance scenario. In addition to an existing public dataset, which contains only single-instance sequences with large amounts of clutter, we have collected two, more challenging, datasets for multiple-instance detection containing heavy 2D and 3D clutter as well as foreground occlusions. We provide extensive experiments on the various parameters of the framework such as patch size, number of trees and number of iterations to infer class distributions at test time. We also evaluate the Latent-Class Hough Forests on all datasets where we outperform state of the art methods.

  4. Does diazinon pose a threat to a neighborhood stream in Tallahassee, Florida?

    USGS Publications Warehouse

    Berndt, Marian P.; Hatzell, Hilda H.

    2001-01-01

    The water quality of Lafayette Creek was studied from March 1993 to December 1995 as part of the National Water-Quality Assessment Program of the U.S.Geological Survey. Diazinon was specifically studied in the Lafayette Creek watershed, a residential area in northeastern Tallahassee, Fla. Diazinon and other pesticides applied directly to the soil or grass can be washed off into nearby storm drains, ditches, streams, and lakes. Heavy rainstorms can wash substantial amounts of chemicals into streams and lakes, including diazinon that was applied several weeks earlier. Sampling streams during rainstorms for water quality can sometimes provide clues about how pesticides and other contaminants are transported to surface water. Diazinon was detected in 92% of all samples collected from Lafayette Creek and it was detected throughout the year during the sampling period. However, concentrations were low (0.002 to 0.28 micrograms per liter) and do not pose a risk to human health. About 20% of the samples exceeded the aquatic-life criterion--a guideline that establishes the maximum acceptable level of concentrations of pesticides for protecting aquatic life.

  5. The interconnected and cross-border nature of risks posed by infectious diseases.

    PubMed

    Suk, Jonathan E; Van Cangh, Thomas; Beauté, Julien; Bartels, Cornelius; Tsolova, Svetla; Pharris, Anastasia; Ciotti, Massimo; Semenza, Jan C

    2014-01-01

    Infectious diseases can constitute public health emergencies of international concern when a pathogen arises, acquires new characteristics, or is deliberately released, leading to the potential for loss of human lives as well as societal disruption. A wide range of risk drivers are now known to lead to and/or exacerbate the emergence and spread of infectious disease, including global trade and travel, the overuse of antibiotics, intensive agriculture, climate change, high population densities, and inadequate infrastructures, such as water treatment facilities. Where multiple risk drivers interact, the potential impact of a disease outbreak is amplified. The varying temporal and geographic frequency with which infectious disease events occur adds yet another layer of complexity to the issue. Mitigating the emergence and spread of infectious disease necessitates mapping and prioritising the interdependencies between public health and other sectors. Conversely, during an international public health emergency, significant disruption occurs not only to healthcare systems but also to a potentially wide range of sectors, including trade, tourism, energy, civil protection, transport, agriculture, and so on. At the same time, dealing with a disease outbreak may require a range of critical sectors for support. There is a need to move beyond narrow models of risk to better account for the interdependencies between health and other sectors so as to be able to better mitigate and respond to the risks posed by emerging infectious disease.

  6. The U.S. Women's World Cup Soccer Team poses with astronauts and Dan Goldin

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Members of the U.S. World Cup Soccer Team pose with Astronauts Scott Parazynski, Heidemarie M. Stefanyshyn-Piper, Steven W. Lindsey, and Nancy Jane Currie and NASA Administrator Daniel Goldin after the team's arrival at the Skid Strip at Cape Canaveral Air Station. The team arrived with First Lady Hillary Rodham Clinton to view the launch of Space Shuttle mission STS- 93. Liftoff is scheduled for 12:36 a.m. EDT July 20. Much attention has been generated over the launch due to Commander Eileen M. Collins, the first woman to serve as commander of a Shuttle mission. The primary payload of the five-day mission is the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes.

  7. Vision-Based Pose Estimation for Robot-Mediated Hand Telerehabilitation.

    PubMed

    Airò Farulla, Giuseppe; Pianu, Daniele; Cempini, Marco; Cortese, Mario; Russo, Ludovico O; Indaco, Marco; Nerino, Roberto; Chimienti, Antonio; Oddo, Calogero M; Vitiello, Nicola

    2016-02-05

    Vision-based Pose Estimation (VPE) represents a non-invasive solution to allow a smooth and natural interaction between a human user and a robotic system, without requiring complex calibration procedures. Moreover, VPE interfaces are gaining momentum as they are highly intuitive, such that they can be used from untrained personnel (e.g., a generic caregiver) even in delicate tasks as rehabilitation exercises. In this paper, we present a novel master-slave setup for hand telerehabilitation with an intuitive and simple interface for remote control of a wearable hand exoskeleton, named HX. While performing rehabilitative exercises, the master unit evaluates the 3D position of a human operator's hand joints in real-time using only a RGB-D camera, and commands remotely the slave exoskeleton. Within the slave unit, the exoskeleton replicates hand movements and an external grip sensor records interaction forces, that are fed back to the operator-therapist, allowing a direct real-time assessment of the rehabilitative task. Experimental data collected with an operator and six volunteers are provided to show the feasibility of the proposed system and its performances. The results demonstrate that, leveraging on our system, the operator was able to directly control volunteers' hands movements.

  8. Face recognition across non-uniform motion blur, illumination, and pose.

    PubMed

    Punnappurath, Abhijith; Rajagopalan, Ambasamudram Narayanan; Taheri, Sima; Chellappa, Rama; Seetharaman, Guna

    2015-07-01

    Existing methods for performing face recognition in the presence of blur are based on the convolution model and cannot handle non-uniform blurring situations that frequently arise from tilts and rotations in hand-held cameras. In this paper, we propose a methodology for face recognition in the presence of space-varying motion blur comprising of arbitrarily-shaped kernels. We model the blurred face as a convex combination of geometrically transformed instances of the focused gallery face, and show that the set of all images obtained by non-uniformly blurring a given image forms a convex set. We first propose a non-uniform blur-robust algorithm by making use of the assumption of a sparse camera trajectory in the camera motion space to build an energy function with l1 -norm constraint on the camera motion. The framework is then extended to handle illumination variations by exploiting the fact that the set of all images obtained from a face image by non-uniform blurring and changing the illumination forms a bi-convex set. Finally, we propose an elegant extension to also account for variations in pose.

  9. A cognitive evaluation of four online search engines for answering definitional questions posed by physicians.

    PubMed

    Yu, Hong; Kaufman, David

    2007-01-01

    The Internet is having a profound impact on physicians' medical decision making. One recent survey of 277 physicians showed that 72% of physicians regularly used the Internet to research medical information and 51% admitted that information from web sites influenced their clinical decisions. This paper describes the first cognitive evaluation of four state-of-the-art Internet search engines: Google (i.e., Google and Scholar.Google), MedQA, Onelook, and PubMed for answering definitional questions (i.e., questions with the format of "What is X?") posed by physicians. Onelook is a portal for online definitions, and MedQA is a question answering system that automatically generates short texts to answer specific biomedical questions. Our evaluation criteria include quality of answer, ease of use, time spent, and number of actions taken. Our results show that MedQA outperforms Onelook and PubMed in most of the criteria, and that MedQA surpasses Google in time spent and number of actions, two important efficiency criteria. Our results show that Google is the best system for quality of answer and ease of use. We conclude that Google is an effective search engine for medical definitions, and that MedQA exceeds the other search engines in that it provides users direct answers to their questions; while the users of the other search engines have to visit several sites before finding all of the pertinent information.

  10. STS-103 crew members and their families pose for a portrait before DEPARTing

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The STS-103 crew pose for a group portrait with their families and loved ones on the runway at Patrick Air Force Base in Cocoa Beach, Fla. They are preparing to board an airplane that will return them to their home base at the Johnson Space Center in Houston following the successful completion of their mission. From left to right, the crew members are Mission Specialists John M. Grunsfeld (Ph.D.), C. Michael Foale (Ph.D.), Claude Nicollier of Switzerland, Jean-Frangois Clervoy of France, and Steven L. Smith; Pilot Scott J. Kelly; and Commander Curtis L. Brown Jr. Discovery landed in darkness the previous evening, Dec. 27, on runway 33 at KSC's Shuttle Landing Facility at 7:00:47 p.m. EST. This was the first time that a Shuttle crew spent the Christmas holiday in space. The STS-103 mission accomplished outfitting the Hubble Space Telescope with six new gyroscopes, six new voltage/temperature improvement kits, a new onboard computer, a new solid state recorder and new data transmitter, a new fine guidance sensor along with new insulation on parts of the orbiting telescope. This was the 96th flight in the Space Shuttle program and the 27th for the orbiter Discovery.

  11. John H. Glenn Jr. poses with his family after arriving at KSC for launch

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-95 Payload Specialist John H. Glenn Jr. (second from right), senator from Ohio, poses (left to right) with his son, David, daughter, Lyn, and (far right) his wife, Annie, after landing at Kennedy Space Center's Shuttle Landing Facility aboard a T-38 jet. Glenn and other crewmembers flew into KSC to make final preparations for launch. Targeted for liftoff at 2 p.m. on Oct. 29, the STS-95 mission includes research payloads such as the Spartan solar-observing deployable spacecraft, the Hubble Space Telescope Orbital Systems Test Platform, the International Extreme Ultraviolet Hitchhiker, as well as the SPACEHAB single module with experiments on space flight and the aging process. The mission is expected to last 8 days, 21 hours and 49 minutes, and return to KSC on Nov. 7. The other STS-95 crew members are Mission Commander Curtis L. Brown Jr., Pilot Steven W. Lindsey, Mission Specialist Scott E. Parazynski, Mission Specialist Stephen K. Robinson, Mission Specialist Pedro Duque, with the European Space Agency (ESA), and Payload Specialist Chiaki Mukai, with the National Space Development Agency of Japan (NASDA).

  12. Specific groundwater vulnerability maps - what pesticides pose largest threat to groundwater?

    NASA Astrophysics Data System (ADS)

    Kodes, Vit; Kodesova, Radka; Kollerova, Marketa

    2010-05-01

    Pesticides as compounds used in large quantities worldwide pose threat to surface and groundwater quality. One of the tools used for groundwater quality protection is a groundwater vulnerability mapping. Specific groundwater vulnerability can vary depending on pesticide properties and soil cover properties unlike the intrinsic groundwater vulnerability that does not account for the properties of a contaminant and interaction between a contaminant and a soil. In order to assess the risk of pesticide leaching, specific groundwater vulnerability maps were constructed for selected pesticides based on DRASTIC methodology modified to specific hydrogeological conditions of the Czech Republic with emphasis on soil cover that plays a key role in pesticides leaching due to adsorption of pesticides on soil particles. Selection of pesticides for groundwater vulnerability mapping was based on following properties: water solubility, soil half-life and Koc. The calculation of groundwater ubiquity score was also used for determination of a leaching potential of individual pesticides. The properties of selected pesticides represent wide range of compounds from those with none leaching potential to those with very good leaching potential. Presented compound-specific groundwater vulnerability maps reflect those properties. Acknowledgement: Authors acknowledge the financial support of the Ministry of Education, Youth and Sports of the Czech Republic (grant No. 2B06095).

  13. Sleep Problems

    MedlinePlus

    ... For Consumers Consumer Information by Audience For Women Sleep Problems Share Tweet Linkedin Pin it More sharing ... PDF 474KB) En Español Medicines to Help You Sleep Tips for Better Sleep Basic Facts about Sleep ...

  14. Thyroid Problems

    MedlinePlus

    ... treated differently. Common thyroid disorders and problems include: Hypothyroidism Hypothyroidism is a disorder in which your thyroid doesn’ ... normal after you get better. If you have hypothyroidism, however, the levels of T4 in your blood ...

  15. Breathing Problems

    MedlinePlus

    ... getting enough air. Sometimes you can have mild breathing problems because of a stuffy nose or intense ... panic attacks Allergies If you often have trouble breathing, it is important to find out the cause.

  16. Kidney Problems

    MedlinePlus

    ... our e-newsletter! Aging & Health A to Z Kidney Problems Basic Facts & Information The kidneys are two ... the production of red blood cells. What are Kidney Diseases? For about one-third of older people, ...

  17. Sexual Problems

    MedlinePlus

    ... for a healthy life Mental health for men Sexual health for men Male infertility Prostate health Sexual problems ... updates. Enter email address Submit Home > Men's Health > Sexual health for men Men's Health This information in Spanish ( ...

  18. Nipple problems

    MedlinePlus

    ... nipple; Nipple problems Images Female breast Intraductal papilloma Mammary gland Abnormal discharge from the nipple Normal female breast ... PA: Elsevier Saunders; 2011:chap 8. Read More Breast cancer Endocrine glands Intraductal papilloma Review Date 11/16/2014 Updated ...

  19. Speech Problems

    MedlinePlus

    ... thinking, but it becomes disorganized as they're speaking. So, someone who clutters may speak in bursts ... refuse to wait patiently for them to finish speaking. If you have a speech problem, it's fine ...

  20. Downstream boundary conditions for viscous flow problems

    NASA Technical Reports Server (NTRS)

    Fix, G.; Gunzburger, M.

    1977-01-01

    The problem of the specification of artificial outflow conditions in flow problems is studied. It is shown that for transport type equations incorrect outflow conditions will adversely affect the solution only in a small region near the outflow boundary, while for elliptic equations, e.g. those governing the streamfunction or pressure, a correct boundary specification is essential. In addition, integral outflow boundary conditions for fluid dynamical problems are considered. It is shown that such conditions are well posed, and their effect on the solutions of the Navier-Stokes equations is also considered.

  1. Augmented saliency model using automatic 3D head pose detection and learned gaze following in natural scenes.

    PubMed

    Parks, Daniel; Borji, Ali; Itti, Laurent

    2015-11-01

    Previous studies have shown that gaze direction of actors in a scene influences eye movements of passive observers during free-viewing (Castelhano, Wieth, & Henderson, 2007; Borji, Parks, & Itti, 2014). However, no computational model has been proposed to combine bottom-up saliency with actor's head pose and gaze direction for predicting where observers look. Here, we first learn probability maps that predict fixations leaving head regions (gaze following fixations), as well as fixations on head regions (head fixations), both dependent on the actor's head size and pose angle. We then learn a combination of gaze following, head region, and bottom-up saliency maps with a Markov chain composed of head region and non-head region states. This simple structure allows us to inspect the model and make comments about the nature of eye movements originating from heads as opposed to other regions. Here, we assume perfect knowledge of actor head pose direction (from an oracle). The combined model, which we call the Dynamic Weighting of Cues model (DWOC), explains observers' fixations significantly better than each of the constituent components. Finally, in a fully automatic combined model, we replace the oracle head pose direction data with detections from a computer vision model of head pose. Using these (imperfect) automated detections, we again find that the combined model significantly outperforms its individual components. Our work extends the engineering and scientific applications of saliency models and helps better understand mechanisms of visual attention.

  2. The geographic distribution of potential risks posed by industrial toxic emissions in the U.S.

    PubMed

    Chakraborty, Jayajit

    2004-01-01

    The Toxics Release Inventory (TRI), compiled annually by the EPA, has emerged as the most comprehensive database on industrial toxic emissions in the U.S. While various risk indicators and pollutant weighting methods have been developed to compare TRI emissions, these measures are rarely used to examine the geography of potential risks posed by toxic emissions at the national scale. This article provides a geographic perspective on the evaluation of industrial pollution by exploring the spatial distribution of the potential health and environmental impacts of TRI emissions across the U.S. Six indicators of potential risk based on the impact benchmarking concept are used to characterize specific human health and environmental concerns: carcinogenic toxicity, noncarcinogenic toxicity, ozone depletion, global warming, smog formation and acid rain formation. Air emission data from the 2000 TRI are used to analyze the six potential impacts at the state level. The objectives are to: (a) examine and compare spatial variations in the distribution of these adverse impacts across the U.S.: and (b) identify the states facing the highest health and environmental risk from industrial toxic releases. The effect of differences in state area and population size on the distribution of the six potential impacts and state rankings for each category are also investigated. While Ohio and Texas receive the highest ranks in all risk categories, Louisiana and West Virginia represent the most "hazardous" states when emissions are weighted by state area and population. The results demonstrate the need to examine the geographic variability of different risk indicators that are used to evaluate TRI emissions, at multiple scales.

  3. Does monensin in chicken manure from poultry farms pose a threat to soil invertebrates?

    PubMed

    Zižek, Suzana; Hrženjak, Rok; Kalcher, Gabrijela Tavčar; Srimpf, Karin; Semrov, Neva; Zidar, Primož

    2011-04-01

    Monensin is a carboxylic polyether ionophore used in the poultry industry as a coccidiostat. It enters the environment via manure from broiler farms. In spite of its potential presence in the environment, information concerning monensin residues in manure and soil and its toxicity to soil organisms are insufficient. In the present study, two beneficial soil invertebrate species, earthworms (Eisenia andrei) and woodlice (Porcellio scaber), were used to assess the toxicity of monensin. Animals were exposed to a range of monensin concentrations via soil or food. Earthworm reproduction was found to be the most susceptible endpoint (NOEC=3.5 mg kg(-1) dry soil; EC(50)=12.7 mg kg(-1) dry soil), while no adverse effects were recorded in isopods (NOEC⩾849mgkg(-1) dry soil, NOEC⩾357mgkg(-1) dry food). The obtained toxicity data were compared with potential concentrations of monensin in soil. In view of this, manure from broiler chickens treated with monensin at a poultry farm was sampled. According to monensin and nitrogen concentrations in the chicken manure and the degradation time of monensin, the predicted environmental concentration (PEC) was calculated. PEC of monensin is around 0.013 mg kg(-1) soil if manure is used after 3 months of composting and 0.05 mg kg(-1) soil if used without storage. Data for earthworm reproduction was used to estimate the predicted no-effect concentration (PNEC). If fresh chicken manure is applied to terrestrial ecosystems, the risk quotient (PEC/PNEC ratio) is above 1, which indicates that monensin might pose an environmental risk under certain conditions. To prevent this, it is strongly recommended to compost chicken manure for several months before using it as fertiliser.

  4. Export of commercial Hass avocados from Argentina poses negligible risk of Ceratitis capitata (Diptera: Tephritidae) infestation.

    PubMed

    Villagrán, M Elvira; Willink, Eduardo; Vera, M Teresa; Follett, Peter

    2012-08-01

    Argentina has to meet quarantine restrictions because of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), to export 'Hass' avocados, Persea americana Miller, to certain countries. Hass avocado at the hard, mature green stage is potentially a conditional nonhost for C. capitata and could open export markets without the need for a quarantine treatment. Trapping data from 1998 to 2006 showed that C. capitata was present in avocado orchards, particularly early in the harvest season. The host status of hard, mature green Hass avocado to C. capitata was evaluated using laboratory and field cage tests under no-choice conditions and by assessing natural levels of infestation in commercially harvested fruit from the main avocado production area. In total, 2,250 hard, mature green avocado fruit were exposed to 11,250 gravid females for 24 or 48 h after harvest in laboratory or field cages, and no infestations were found. During 11 seasons, 5,949 fruit in total were sampled from the trees and 992 fruit were collected from the ground, and in none of them were any live or dead fruit fly larvae found. Inspection of >198,000 commercial fruit at the packinghouse from 1998 to 2011 showed no symptoms of fruit fly infestation. These data exceed the published standards for determination of nonhost status, as well as the Probit 9 standard for development of quarantine treatments. Hass avocado harvested at the hard, mature green stage was not infested by C. capitata and seems to pose a negligible quarantine risk. As a consequence, no postharvest treatment or other quarantine actions should be required by importing countries.

  5. Child food insecurity increases risks posed by household food insecurity to young children's health.

    PubMed

    Cook, John T; Frank, Deborah A; Levenson, Suzette M; Neault, Nicole B; Heeren, Tim C; Black, Maurine M; Berkowitz, Carol; Casey, Patrick H; Meyers, Alan F; Cutts, Diana B; Chilton, Mariana

    2006-04-01

    The US Food Security Scale (USFSS) measures household and child food insecurity (CFI) separately. Our goal was to determine whether CFI increases risks posed by household food insecurity (HFI) to child health and whether the Food Stamp Program (FSP) modifies these effects. From 1998 to 2004, 17,158 caregivers of children ages 36 mo were interviewed in six urban medical centers. Interviews included demographics, the USFSS, child health status, and hospitalization history. Ten percent reported HFI, 12% HFI and CFI (H&CFI). Compared with food-secure children, those with HFI had significantly greater adjusted odds of fair/poor health and being hospitalized since birth, and those with H&CFI had even greater adverse effects. Participation in the FSP modified the effects of FI on child health status and hospitalizations, reducing, but not eliminating, them. Children in FSP-participating households that were HFI had lower adjusted odds of fair/poor health [1.37 (95% CI, 1.06-1.77)] than children in similar non-FSP households [1.61 (95% CI, 1.31-1.98)]. Children in FSP-participating households that were H&CFI also had lower adjusted odds of fair/poor health [1.72 (95% CI, 1.34-2.21)] than in similar non-FSP households [2.14 (95% CI, 1.81-2.54)]. HFI is positively associated with fair/poor health and hospitalizations in young children. With H&CFI, odds of fair/poor health and hospitalizations are even greater. Participation in FSP reduces, but does not eliminate, effects of FI on fair/poor health.

  6. Do shade-grown coffee plantations pose a disease risk for wild birds?

    PubMed

    Hernandez, Sonia M; Peters, Valerie E; Weygandt, P Logan; Jimenez, Carlos; Villegas, Pedro; O'Connor, Barry; Yabsley, Michael J; Garcia, Maricarmen; Riblet, Sylva M; Carroll, C Ron

    2013-06-01

    Shade-grown coffee plantations are often promoted as a conservation strategy for wild birds. However, these agro-ecosystems are actively managed for food production, which may alter bird behaviors or interactions that could change bird health, compared to natural forest. To examine whether there is a difference between the health parameters of wild birds inhabiting shade-grown coffee plantations and natural forest, we evaluated birds in Costa Rica for (1) their general body condition, (2) antibodies to pathogens, (paramyxovirus and Mycoplasma spp.), and (3) the prevalence and diversity of endo-, ecto-, and hemoparasites. We measured exposure to Mycoplasma spp. and paramyxovirus because these are pathogens that could have been introduced with domestic poultry, one mechanism by which these landscapes could be detrimental to wild birds. We captured 1,561 birds representing 75 species. Although seasonal factors influenced body condition, we did not find bird general body condition to be different. A total of 556 birds of 31 species were tested for antibodies against paramyxovirus-1. Of these, five birds tested positive, four of which were from shade coffee. Out of 461 other tests for pathogens (for antibodies and nucleotide detection), none were positive. Pterolichus obtusus, the feather mite of chickens, was found on 15 birds representing two species and all were from shade-coffee plantations. Larvated eggs of Syngamus trachea, a nematode typically associated with chickens, were found in four birds captured in shade coffee and one captured in forest. For hemoparasites, a total of 1,121 blood smears from 68 bird species were examined, and only one species showed a higher prevalence of infection in shade coffee. Our results indicate that shade-coffee plantations do not pose a significant health risk to forest birds, but at least two groups of pathogens may deserve further attention: Haemoproteus spp. and the diversity and identity of endoparasites.

  7. Historical state of knowledge of the health risks of asbestos posed to seamen on merchant ships.

    PubMed

    Dodge, David G; Beck, Barbara D

    2016-12-01

    We examined the development of knowledge concerning the risks posed by asbestos to seamen working aboard merchant ships at sea (i.e. commercial, rather than naval vessels). Seamen were potentially exposed to "in-place" asbestos on merchant ships by performing intermittent repair and maintenance tasks. We reviewed studies measuring airborne asbestos onboard merchant ships and health outcomes of merchant seamen, as well as studies, communications, and actions of U.S. organizations with roles in maritime health and safety. Up to the 1970s, most knowledge of the health risks of asbestos was derived from studies of workers in asbestos product manufacturing and asbestos mining and milling industries, and certain end-users of asbestos products (particularly insulators). We found that attention to the potential health risks of asbestos to merchant seamen began in the mid- to late 1970s and early 1980s. Findings of pleural abnormalities in U.S. seamen elicited some concern from governmental and industry/labor organizations, but airborne asbestos concentrations aboard merchant ships were found to be <1 f/cc for most short-term repair and maintenance tasks. Responses to this evolving information served to warn seamen and the merchant shipping industry and led to increased precautions regarding asbestos exposure. Starting in the 1990s, findings of modest increases in lung cancer and/or mesothelioma in some epidemiology studies of seamen led some authors to propose that a causal link between shipboard exposures and asbestos-related diseases existed. Limitations in these studies, however, together with mostly unremarkable measures of airborne asbestos on merchant ships, preclude definitive conclusions in this regard.

  8. Estimation of the environmental risk posed by landfills using chemical, microbiological and ecotoxicological testing of leachates.

    PubMed

    Matejczyk, Marek; Płaza, Grażyna A; Nałęcz-Jawecki, Grzegorz; Ulfig, Krzysztof; Markowska-Szczupak, Agata

    2011-02-01

    parameters of the landfill leachates should be analyzed together to assess the environmental risk posed by landfill emissions.

  9. Optimization of multi-image pose recovery of fluoroscope tracking (FTRAC) fiducial in an image-guided femoroplasty system

    NASA Astrophysics Data System (ADS)

    Liu, Wen P.; Armand, Mehran; Otake, Yoshito; Taylor, Russell H.

    2011-03-01

    Percutaneous femoroplasty [1], or femoral bone augmentation, is a prospective alternative treatment for reducing the risk of fracture in patients with severe osteoporosis. We are developing a surgical robotics system that will assist orthopaedic surgeons in planning and performing a patient-specific, augmentation of the femur with bone cement. This collaborative project, sponsored by the National Institutes of Health (NIH), has been the topic of previous publications [2],[3] from our group. This paper presents modifications to the pose recovery of a fluoroscope tracking (FTRAC) fiducial during our process of 2D/3D registration of X-ray intraoperative images to preoperative CT data. We show improved automata of the initial pose estimation as well as lower projection errors with the advent of a multiimage pose optimization step.

  10. Binding mode similarity measures for ranking of docking poses: a case study on the adenosine A2A receptor

    NASA Astrophysics Data System (ADS)

    Anighoro, Andrew; Bajorath, Jürgen

    2016-06-01

    We report an investigation designed to explore alternative approaches for ranking of docking poses in the search for antagonists of the adenosine A2A receptor, an attractive target for structure-based virtual screening. Calculation of 3D similarity of docking poses to crystallographic ligand(s) as well as similarity of receptor-ligand interaction patterns was consistently superior to conventional scoring functions for prioritizing antagonists over decoys. Moreover, the use of crystallographic antagonists and agonists, a core fragment of an antagonist, and a model of an agonist placed into the binding site of an antagonist-bound form of the receptor resulted in a significant early enrichment of antagonists in compound rankings. Taken together, these findings showed that the use of binding modes of agonists and/or antagonists, even if they were only approximate, for similarity assessment of docking poses or comparison of interaction patterns increased the odds of identifying new active compounds over conventional scoring.

  11. An Automated Strategy for Binding-Pose Selection and Docking Assessment in Structure-Based Drug Design.

    PubMed

    Ballante, Flavio; Marshall, Garland R

    2016-01-25

    Molecular docking is a widely used technique in drug design to predict the binding pose of a candidate compound in a defined therapeutic target. Numerous docking protocols are available, each characterized by different search methods and scoring functions, thus providing variable predictive capability on a same ligand-protein system. To validate a docking protocol, it is necessary to determine a priori the ability to reproduce the experimental binding pose (i.e., by determining the docking accuracy (DA)) in order to select the most appropriate docking procedure and thus estimate the rate of success in docking novel compounds. As common docking programs use generally different root-mean-square deviation (RMSD) formulas, scoring functions, and format results, it is both difficult and time-consuming to consistently determine and compare their predictive capabilities in order to identify the best protocol to use for the target of interest and to extrapolate the binding poses (i.e., best-docked (BD), best-cluster (BC), and best-fit (BF) poses) when applying a given docking program over thousands/millions of molecules during virtual screening. To reduce this difficulty, two new procedures called Clusterizer and DockAccessor have been developed and implemented for use with some common and "free-for-academics" programs such as AutoDock4, AutoDock4(Zn), AutoDock Vina, DOCK, MpSDockZn, PLANTS, and Surflex-Dock to automatically extrapolate BD, BC, and BF poses as well as to perform consistent cluster and DA analyses. Clusterizer and DockAccessor (code available over the Internet) represent two novel tools to collect computationally determined poses and detect the most predictive docking approach. Herein an application to human lysine deacetylase (hKDAC) inhibitors is illustrated.

  12. Pose prediction accuracy in docking studies and enrichment of actives in the active site of GSK-3beta.

    PubMed

    Gadakar, Pravin Kumar; Phukan, Samiron; Dattatreya, Prasanna; Balaji, V N

    2007-01-01

    We present molecular docking studies on the inhibitors of GSK-3beta kinase in the enzyme binding sites of the X-ray complexes (1H8F, 1PYX, 1O9U, 1Q4L, 1Q5K, and 1UV5) using the Schrödinger docking tool Glide. Cognate and cross-docking studies using standard precision (SP) and extraprecision (XP) algorithms have been carried out. Cognate docking studies demonstrate that docked poses similar to X-ray poses (root-mean-square deviations of less than 2 A) are found within the top four ranks of the GlideScore and E-model scores. However, cross-docking studies typically produce poses that are significantly deviated from X-ray poses in all but a couple of cases, implying potential for induced fit effects in ligand binding. In this light, we have also carried out induced fit docking studies in the active sites of 1O9U, 1Q4L, and 1Q5K. Specifically, conformational changes have been effected in the active sites of these three protein structures to dock noncognate ligands. Thus, for example, the active site of 1O9U has been induced to fit the ligands of 1Q4L, 1Q5K, and 1UV5. These studies produce ligand docked poses which have significantly lower root-mean-square deviations relative to their X-ray crystallographic poses, when compared to the corresponding values from the cross-docking studies. Furthermore, we have used an ensemble of the induced fit models and X-ray structures to enhance the retrieval of active GSK-3beta inhibitors seeded in a decoy database, normally used in Glide validation studies. Thus, our studies provide valuable insights into computational strategies useful for the identification of potential GSK-3beta inhibitors.

  13. 3D pose estimation and motion analysis of the articulated human hand-forearm limb in an industrial production environment

    NASA Astrophysics Data System (ADS)

    Hahn, Markus; Barrois, Björn; Krüger, Lars; Wöhler, Christian; Sagerer, Gerhard; Kummert, Franz

    2010-09-01

    This study introduces an approach to model-based 3D pose estimation and instantaneous motion analysis of the human hand-forearm limb in the application context of safe human-robot interaction. 3D pose estimation is performed using two approaches: The Multiocular Contracting Curve Density (MOCCD) algorithm is a top-down technique based on pixel statistics around a contour model projected into the images from several cameras. The Iterative Closest Point (ICP) algorithm is a bottom-up approach which uses a motion-attributed 3D point cloud to estimate the object pose. Due to their orthogonal properties, a fusion of these algorithms is shown to be favorable. The fusion is performed by a weighted combination of the extracted pose parameters in an iterative manner. The analysis of object motion is based on the pose estimation result and the motion-attributed 3D points belonging to the hand-forearm limb using an extended constraint-line approach which does not rely on any temporal filtering. A further refinement is obtained using the Shape Flow algorithm, a temporal extension of the MOCCD approach, which estimates the temporal pose derivative based on the current and the two preceding images, corresponding to temporal filtering with a short response time of two or at most three frames. Combining the results of the two motion estimation stages provides information about the instantaneous motion properties of the object. Experimental investigations are performed on real-world image sequences displaying several test persons performing different working actions typically occurring in an industrial production scenario. In all example scenes, the background is cluttered, and the test persons wear various kinds of clothes. For evaluation, independently obtained ground truth data are used. [Figure not available: see fulltext.

  14. Rigid and non-rigid geometrical transformations of a marker-cluster and their impact on bone-pose estimation.

    PubMed

    Bonci, T; Camomilla, V; Dumas, R; Chèze, L; Cappozzo, A

    2015-11-26

    When stereophotogrammetry and skin-markers are used, bone-pose estimation is jeopardised by the soft tissue artefact (STA). At marker-cluster level, this can be represented using a modal series of rigid (RT; translation and rotation) and non-rigid (NRT; homothety and scaling) geometrical transformations. The NRT has been found to be smaller than the RT and claimed to have a limited impact on bone-pose estimation. This study aims to investigate this matter and comparatively assessing the propagation of both STA components to bone-pose estimate, using different numbers of markers. Twelve skin-markers distributed over the anterior aspect of a thigh were considered and STA time functions were generated for each of them, as plausibly occurs during walking, using an ad hoc model and represented through the geometrical transformations. Using marker-clusters made of four to 12 markers affected by these STAs, and a Procrustes superimposition approach, bone-pose and the relevant accuracy were estimated. This was done also for a selected four marker-cluster affected by STAs randomly simulated by modifying the original STA NRT component, so that its energy fell in the range 30-90% of total STA energy. The pose error, which slightly decreased while increasing the number of markers in the marker-cluster, was independent from the NRT amplitude, and was always null when the RT component was removed. It was thus demonstrated that only the RT component impacts pose estimation accuracy and should thus be accounted for when designing algorithms aimed at compensating for STA.

  15. SCREENING TO IDENTIFY AND PREVENT URBAN STORM WATER PROBLEMS: ESTIMATING IMPERVIOUS AREA ACCURATELY AND INEXPENSIVELY

    EPA Science Inventory

    Complete identification and eventual prevention of urban water quality problems pose significant monitoring, "smart growth" and water quality management challenges. Uncontrolled increase of impervious surface area (roads, buildings, and parking lots) causes detrimental hydrologi...

  16. SCREENING TO IDENTIFY AND PREVENT URBAN STORM WATER PROBLEMS: ESTIMATING IMPERVIOUS AREA ACCURATELY AND CHEAPLY

    EPA Science Inventory

    Complete identification and eventual prevention of urban/suburban water quality problems pose significant monitoring challenges. Uncontrolled growth of impervious surfaces (roads, buildings and parking) causes detrimental hydrologic changes, stream channel erosion, habitat degra...

  17. Spacecraft Charging - Present Situation and Some Problems

    DTIC Science & Technology

    2007-06-01

    does not have a magnetosphereand is therefore exposed to the solar winds. It is dusty on the moon. More on charging of lunar dust 18 in solarwind plasmas...with energy distributions needs to be studied systematically. The small dust size poses problems tosecondary electron emission, because the secondary...energetic enough, can pass through a dust particle and exit from the oppositeside. Depending on the size distribution of the dust particles 21-22 and the

  18. Heat Problems.

    ERIC Educational Resources Information Center

    Connors, G. Patrick

    Heat problems and heat cramps related to jogging can be caused by fluid imbalances, medications, dietary insufficiency, vomiting or diarrhea, among other factors. If the condition keeps reoccurring, the advice of a physician should be sought. Some preventive measures that can be taken include: (1) running during the cooler hours of the day; (2)…

  19. Puzzles & Problems.

    ERIC Educational Resources Information Center

    Murphy, Pat, Ed.

    1993-01-01

    "Exploring" is a magazine of science, art, and human perception, produced by Exploratorium in collaboration with other participating museums. This issue focuses on puzzles and problem solving. Brain teasers, puzzles, and the strategies for solving them are included. Features include: (1) "Homework Assignment #3" (Paul Doherty);…

  20. Development and analysis of a well-posed model for the turbulent dispersion tensor

    NASA Astrophysics Data System (ADS)

    Shabany Sheikhan Gafsheh, Younes

    1999-10-01

    The transport of a passive scalar in high-Reynolds-number turbulent flows is controlled by the flow and is independent from the passive scalar itself. Therefore, turbulent dispersion is a function of the velocity field and Reynolds stresses. On the other hand, the transport equation for a passive scalar is a linear partial differential equation; any modeled form of the equation has to preserve this property and the superposition principle. It is shown that, in a homogeneous and high-Reynolds- number flow, an evolution equation for the dispersion tensor can be obtained from a model transport equation for the turbulent scalar flux and the definition of the dispersion tensor. This equation shows that the dispersion tensor is a function of the flow field only. It is shown that, in the limit of high Reynolds/Peclet number flows, the symmetric part of the dispersion tensor has to be a positive semidefinite tensor. This is the well-posedness condition for the dispersion tensor. It is observed that the solution of the evolution equation for the dispersion tensor, obtained from the general linear transport equation for the turbulent scalar fluxes, does not satisfy this condition in some cases. A modification to this model is proposed to prevent any solution which is not well posed. The equilibrium assumption for the normalized dispersion tensor results in an implicit algebraic expression for the dispersion tensor. A new method is proposed to solve the implicit expression in order to obtain an explicit algebraic model for the dispersion tensor. The model constants are found using channel flow DNS data as well as turbulent boundary layer experimental data. The present model gives good predictions of the heat transfer rates and the temperature profiles in boundary layers with constant wall temperature and with a step change in wall temperature. The model predictions show good agreements with the experimental data on channel flows with constant wall temperature and with a step