WorldWideScience

Sample records for avoidance

  1. Avoid Logs to Avoid Ticks

    Institute of Scientific and Technical Information of China (English)

    莫文佳

    2004-01-01

    扁虱是莱姆关节炎的罪魁祸首。研究人员为了弄明白何处扁虱最猖獗, 不惜以身作饵,他们发现:The ticks were all over the log surface。因此告诫人 们:Avoid sitting on logs。

  2. Teachers Avoiding Learners' Avoidance: Is It Possible?

    Science.gov (United States)

    Tadayyon, Maedeh; Zarrinabadi, Nourollah; Ketabi, Saeed

    2016-01-01

    Dealing with learners who prefer to take the back seat and avoid classroom participation can be every teacher's nightmare. This lack of participation may cause teacher frustration, and possibly the only way to reduce this lack of participation is to access the concept of avoidance strategy. Avoidance strategy is the abandonment of a classroom task…

  3. Avoidant personality disorder

    Science.gov (United States)

    ... Names Personality disorder - avoidant References American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. Arlington, VA: American Psychiatric Publishing. 2013. ...

  4. Avoidable mortality in Lithuania.

    OpenAIRE

    Gaizauskiene, A.; Gurevicius, R

    1995-01-01

    STUDY OBJECTIVE--The study aimed to analyse avoidable mortality in Lithuania as an index of the quality of health care and to assess trends in avoidable mortality from 1970-90. SETTING AND PARTICIPANTS--All deaths of Lithuanian residents aged between 0 and 64 years between 1970 and 1990 were analysed. MEASUREMENTS AND MAIN RESULTS--Twenty seven per cent of all deaths in this age group were avoidable. Avoidable deaths were grouped into preventable and treatable ones. Treatable causes of death ...

  5. Psychological Treatments to Avoid

    Science.gov (United States)

    Thomason, Timothy C.

    2010-01-01

    Certain psychological treatments should be avoided, and a list of such treatments would provide valuable guidance for counselors, as well as potential clients. It is well established that some therapies are potentially dangerous, and some fringe therapies are highly unlikely to help clients beyond a placebo effect. This article provides an…

  6. Avoiding the Flu

    Science.gov (United States)

    ... of this page please turn Javascript on. Feature: Flu Avoiding the Flu Past Issues / Fall 2009 Table of Contents Children ... should still get the 2009 H1N1 vaccine. H1N1 Flu: Who Should Be Vaccinated First The Centers for ...

  7. Myelin Avoids the JAM.

    Science.gov (United States)

    Follis, Rose M; Carter, Bruce D

    2016-08-17

    In this issue of Neuron, Redmond et al. (2016) identify junction adhesion molecule 2 (JAM2) as an inhibitor of somatodendritic myelination in spinal cord neurons, thereby elucidating how myelin forms on axons but avoids dendrites and cell bodies. PMID:27537479

  8. Plants to Avoid

    Science.gov (United States)

    Knowledge of poisonous plants is extremely important for home owners, gardeners, farmers, hunters, hikers, and the rest of the general public. Among the most important plants to avoid in the Delta Region are poison ivy, bull nettle, eastern black nightshade, Queen Ann’s lace, jimsonweed, and trumpe...

  9. AVOIDING MANUSCRIPT MISTAKES

    OpenAIRE

    Grindstaff, Terry L.; Saliba, Susan A.

    2012-01-01

    Writing a scientific manuscript can be a consuming, but rewarding task with a number of intrinsic and extrinsic benefits. The ability to write a scientific manuscript is typically not an emphasized component of most entry‐level professional programs. The purpose of this overview is to provide authors with suggestions to improve manuscript quality and to provide mechanisms to avoid common manuscript mistakes that are often identified by journal reviewers and editors.

  10. Indonesia : Avoiding the Trap

    OpenAIRE

    World Bank

    2014-01-01

    Within the next two decades Indonesia aspires to generate prosperity, avoid a middle-income trap and leave no one behind as it tries to catch up with high-income economies. These are ambitious goals. Realizing them requires sustained high growth and job creation, as well as reduced inequality. Can Indonesia achieve them? This report argues that the country has the potential to rise and bec...

  11. On partitions avoiding right crossings

    OpenAIRE

    Yan, Sherry H. F.; Xu, Yuexiao

    2011-01-01

    Recently, Chen et al. derived the generating function for partitions avoiding right nestings and posed the problem of finding the generating function for partitions avoiding right crossings. In this paper, we derive the generating function for partitions avoiding right crossings via an intermediate structure of partial matchings avoiding 2-right crossings and right nestings. We show that there is a bijection between partial matchings avoiding 2-right crossing and right nestings and partitions...

  12. Avoidable waste management costs

    International Nuclear Information System (INIS)

    This report describes the activity based costing method used to acquire variable (volume dependent or avoidable) waste management cost data for routine operations at Department of Energy (DOE) facilities. Waste volumes from environmental restoration, facility stabilization activities, and legacy waste were specifically excluded from this effort. A core team consisting of Idaho National Engineering Laboratory, Los Alamos National Laboratory, Rocky Flats Environmental Technology Site, and Oak Ridge Reservation developed and piloted the methodology, which can be used to determine avoidable waste management costs. The method developed to gather information was based on activity based costing, which is a common industrial engineering technique. Sites submitted separate flow diagrams that showed the progression of work from activity to activity for each waste type or treatability group. Each activity on a flow diagram was described in a narrative, which detailed the scope of the activity. Labor and material costs based on a unit quantity of waste being processed were then summed to generate a total cost for that flow diagram. Cross-complex values were calculated by determining a weighted average for each waste type or treatability group based on the volume generated. This study will provide DOE and contractors with a better understanding of waste management processes and their associated costs. Other potential benefits include providing cost data for sites to perform consistent cost/benefit analysis of waste minimization and pollution prevention (WMIN/PP) options identified during pollution prevention opportunity assessments and providing a means for prioritizing and allocating limited resources for WMIN/PP

  13. Redundant Robot Can Avoid Obstacles

    Science.gov (United States)

    Homayoun, Seraji; Colbaugh, Richard; Glass, Kristin

    1991-01-01

    Simple and direct control scheme enables redundant robot to avoid obstacles in workspace. In proposed scheme, called "configuration control", degrees of freedom used to configure robot to satisfy set of inequality constraints representing avoidance of obstacles, while simultaneously making end effector follow desired trajectory. Provides capability to avoid obstacles in dynamically varying environment where apriori planning of tasks not feasible.

  14. MEST- avoid next extinction

    Science.gov (United States)

    Cao, Dayong

    2012-11-01

    Asteroid 2011 AG5 will impact on Earth in 2040. (See Donald K. Yoemans, ``Asteroid 2011 AG5 - A Reality Check,'' NASA-JPL, 2012) In 2011, The author say: the dark hole will take the dark comet to impact our solar system in 20 years, and give a systemic model between the sun and its companion-dark hole to explain why were there periodicity mass extinction on earth. (see Dayong Cao, BAPS.2011.CAL.C1.7, BAPS.2011.DFD.LA.24, BAPS.2012.APR.K1.78 and BAPS.2011.APR.K1.17) The dark Asteroid 2011 AG5 (as a dark comet) is made of the dark matter which has a space-time (as frequence-amplitude square) center- a different systemic model from solar systemic model. It can asborb the space-time and wave. So it is ``dark.'' When many dark matters hit on our earth, they can break our atom structure and our genetic code to trigger the Mass Extinction. In our experiments, consciousness can change the systematic model and code by a life-informational technology. So it can change the output signals of the solar cell. (see Dayong Cao, BAPS.2011.MAR.C1.286 and BAPS.2012.MAR.P33.14) So we will develop the genetic code of lives to evolution and sublimation, will use the dark matter to change the systemic model between dark hole and sun and will avoid next extinction.

  15. Endless self-avoiding walks

    OpenAIRE

    Clisby, Nathan

    2013-01-01

    We introduce a self-avoiding walk model for which end-effects are completely eliminated. We enumerate the number of these walks for various lattices in dimensions two and three, and use these enumerations to study the properties of this model. We find that endless self-avoiding walks have the same connective constant as self-avoiding walks, and the same Flory exponent $\

  16. Communication Avoiding ILU0 Preconditioner

    OpenAIRE

    Grigori, Laura; Moufawad, Sophie

    2013-01-01

    In this paper we present a communication avoiding ILU0 preconditioner for solving large linear systems of equations by using iterative Krylov subspace methods. Recent research has focused on communication avoiding Krylov subspace methods based on so called s-step methods. However there is no communication avoiding preconditioner yet, and this represents a serious limitation of these methods. Our preconditioner allows to perform s iterations of the iterative method with no communication, throu...

  17. Extendable self-avoiding walks

    OpenAIRE

    Grimmett, Geoffrey R.; Holroyd, Alexander E; Peres, Yuval

    2013-01-01

    The connective constant mu of a graph is the exponential growth rate of the number of n-step self-avoiding walks starting at a given vertex. A self-avoiding walk is said to be forward (respectively, backward) extendable if it may be extended forwards (respectively, backwards) to a singly infinite self-avoiding walk. It is called doubly extendable if it may be extended in both directions simultaneously to a doubly infinite self-avoiding walk. We prove that the connective constants for forward,...

  18. Prudent Self-Avoiding Walks

    Directory of Open Access Journals (Sweden)

    Anthony J. Guttmann

    2008-09-01

    Full Text Available We have produced extended series for prudent self-avoiding walks on the square lattice. These are subsets of self-avoiding walks. We conjecture the exact growth constant and critical exponent for the walks, and show that the (anisotropic generating function is almost certainly not differentiably-finite.

  19. Prudent Self-Avoiding Walks

    OpenAIRE

    Guttmann, Anthony J.; Dethridge, John C.

    2008-01-01

    We have produced extended series for prudent self-avoiding walks on the square lattice. These are subsets of self-avoiding walks. We conjecture the exact growth constant and critical exponent for the walks, and show that the (anisotropic) generating function is almost certainly not differentiably-finite.

  20. Acquaintance Rape: Effective Avoidance Strategies.

    Science.gov (United States)

    Levine-MacCombie, Joyce; Koss, Mary P.

    1986-01-01

    Determined that acknowledged and unacknowledged acquaintance rape victims and rape avoiders could be discriminated by situational variables and response strategies. Avoiders were less likely to have experienced passive or internalizing emotions at the time of the assault, perceived the assault as less violent, and were more likely to have utilized…

  1. Neuromorphic UAS Collision Avoidance Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Using biologically-inspired neuromorphic optic flow algorithms is a novel approach in collision avoidance for UAS. Traditional computer vision algorithms rely on...

  2. Panic disorder and exercise avoidance

    Directory of Open Access Journals (Sweden)

    Ricardo W. Muotri

    2014-03-01

    Full Text Available Objectives: 1 To identify whether patients with panic disorder in general and those with the respiratory subtype in particular actively avoid exercise; 2 to investigate physiological differences in cardiopulmonary function parameters in patients with panic disorder in general, patients with the respiratory subtype of panic disorder, and healthy controls upon exercise challenge. Methods: Patients with panic disorder were classified as having either the respiratory or the non-respiratory subtype. Both groups were compared to controls in terms of exercise avoidance patterns and performance on cardiopulmonary exercise testing. Results: Patients with panic disorder exhibited higher exercise avoidance scores and worse performance on cardiopulmonary exercise testing as compared with controls. No differences were found between patients with the respiratory and non-respiratory subtypes. Conclusions: Exercise avoidance is present in panic disorder and is associated with poorer performance on cardiopulmonary exercise testing. These findings are not limited to patients with the respiratory subtype of the disorder.

  3. Endless self-avoiding walks

    Science.gov (United States)

    Clisby, Nathan

    2013-06-01

    We introduce a self-avoiding walk model for which end-effects are completely eliminated. We enumerate the number of these walks for various lattices in dimensions two and three, and use these enumerations to study the properties of this model. We find that endless self-avoiding walks have the same connective constant as self-avoiding walks, and the same Flory exponent ν. However, there is no power law correction to the exponential number growth for this new model, i.e. the critical exponent γ = 1 exactly in any dimension. In addition, the number growth has no analytic corrections to scaling, and we have convincing numerical evidence to support the conjecture that the amplitude for the number growth is a universal quantity. The technique by which end-effects are eliminated may be generalized to other models of polymers such as interacting self-avoiding walks.

  4. Endless self-avoiding walks

    International Nuclear Information System (INIS)

    We introduce a self-avoiding walk model for which end-effects are completely eliminated. We enumerate the number of these walks for various lattices in dimensions two and three, and use these enumerations to study the properties of this model. We find that endless self-avoiding walks have the same connective constant as self-avoiding walks, and the same Flory exponent ν. However, there is no power law correction to the exponential number growth for this new model, i.e. the critical exponent γ = 1 exactly in any dimension. In addition, the number growth has no analytic corrections to scaling, and we have convincing numerical evidence to support the conjecture that the amplitude for the number growth is a universal quantity. The technique by which end-effects are eliminated may be generalized to other models of polymers such as interacting self-avoiding walks. (paper)

  5. Avoidable nightmare; Der vermeidbare Albtraum

    Energy Technology Data Exchange (ETDEWEB)

    Sieg, Mirco

    2010-07-01

    Failure of photovoltaic systems because of serious damage is an increasing phenomenon. Especially in older systems, faulty projecting and installation may have costly late effects. Insurance companies reckon that most cases of damage and failure could easily be avoided. (orig.)

  6. Vision-based obstacle avoidance

    Science.gov (United States)

    Galbraith, John

    2006-07-18

    A method for allowing a robot to avoid objects along a programmed path: first, a field of view for an electronic imager of the robot is established along a path where the electronic imager obtains the object location information within the field of view; second, a population coded control signal is then derived from the object location information and is transmitted to the robot; finally, the robot then responds to the control signal and avoids the detected object.

  7. Self-avoiding quantum walks

    OpenAIRE

    Camilleri, Elizabeth; Rohde, Peter P.; Twamley, Jason

    2014-01-01

    Quantum walks exhibit many unique characteristics compared to classical random walks. In the classical setting, self-avoiding random walks have been studied as a variation on the usual classical random walk. Classical self-avoiding random walks have found numerous applications, most notably in the modeling of protein folding. We consider the analogous problem in the quantum setting. We complement a quantum walk with a memory register that records where the walker has previously resided. The w...

  8. Who participates in tax avoidance?

    OpenAIRE

    Alstadsæter, Annette; Jacob, Martin

    2013-01-01

    This paper analyzes the sources of heterogeneity in legal tax avoidance strategies across individuals. Three conditions are required for a taxpayer to participate in tax avoidance: incentive, access, and awareness. Using rich Swedish administrative panel data with a unique link between corporate and individual tax returns, we analyze individual participation in legal tax planning around the 2006 Swedish tax reform. Our results suggest that closely held corporations are utilized to facilitate ...

  9. Predator Avoidance in Extremophile Fish

    Directory of Open Access Journals (Sweden)

    Martin Plath

    2013-02-01

    Full Text Available Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre and the adjacent sulfidic surface creek (El Azufre, we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve and wild-caught (i.e., predator-experienced individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1 that predator avoidance is still functional in extremophile Poecilia spp. and (2 that predator recognition and avoidance reactions have a strong genetic basis.

  10. Avoidance: grammatical or semantic causes?

    OpenAIRE

    Hulstijn, J.H.; de Marchena, E.

    1989-01-01

    This article follows up on a study by Dagut and Laufer (1985), who found that Hebrew learners of English avoid phrasal verbs, such as ‘let down’, while preferring one-word verbs, such as ‘;disappoint’, since phrasal verbs do not exist in Hebrew. A corollary derived from Dagut and Laufer's study is that Dutch learners of English would tend not to avoid English phrasal verbs, since phrasal verbs also exist in Dutch. It was hypothesized, however, that Dutch learners of English as a second langua...

  11. Avoiding unfavourable outcomes in liposuction

    Directory of Open Access Journals (Sweden)

    Atul Khanna

    2013-01-01

    Full Text Available The origin of liposuction can be traced to an adverse event by Dujarrier in 1921 when he used a uterine curette to remove fat from the knees of a ballerina ending in an amputation secondary to damage of the femoral artery. The history of liposuction since then has been one of avoiding complications and optimising outcome. After this adverse event, liposuction was abandoned until the 1960′s when Schrudde revived the practice using small stab incisions and sharp curettage with the secondary suction to aspirate the freed tissue. This technique was associated with a high incidence of complications especially seroma and skin necrosis. Illouz then replaced the curette with a blunt cannula connected to vacuum pump thus avoiding the complications of a sharp curette. Despite the presence of various techniques for liposuction, suction assisted liposuction (SAL is still the standard technique of liposuction. This article aims to discuss literature regarding the various aspects of liposuction (SAL and to highlight the salient points in the literature and in the senior author′s experience in order to avoid unfavourable outcomes in liposuction. A literature review on avoiding complication is in liposuction including some of the seminal papers on liposuction. Liposuction is generally a safe procedure with reproducible outcome. Just like any surgical procedure it should be treated with the utmost care. Illouz published 10 commandments for liposuction in 1989 and we review these commandments to demonstrate how liposuction has evolved.

  12. Avoiding plagiarism in academic writing.

    Science.gov (United States)

    Anderson, Irene

    Plagiarism means taking the work of another and presenting it as one's own, resulting in potential upset for the original author and disrepute for the professions involved. This article aims to explore the issue of plagiarism and some mechanisms for detection and avoidance. PMID:19186631

  13. Plagiarism Avoidance in Academic Submissions

    OpenAIRE

    Cully, Philip

    2013-01-01

    The purpose of this paper is to provide undergraduate students with an introductory resource focusing on plagiarism avoidance. It sets out to identify often confusing associated nuances. From the perspective of paraphrasing, the requirements attaching to the necessary provision of proper citations are explored. The paper concludes by pondering the topic of reliability of sources.

  14. Avoidance: grammatical or semantic causes?

    NARCIS (Netherlands)

    J.H. Hulstijn; E. Marchena

    1989-01-01

    This article follows up on a study by Dagut and Laufer (1985), who found that Hebrew learners of English avoid phrasal verbs, such as ‘let down’, while preferring one-word verbs, such as ‘;disappoint’, since phrasal verbs do not exist in Hebrew. A corollary derived from Dagut and Laufer's study is t

  15. Obstacle Avoidance Through Visual Teleoperation

    Directory of Open Access Journals (Sweden)

    Muhammad Usman Keerio

    2009-01-01

    Full Text Available This paper presents a novel controlling approach forHumanoid Robot to work safely in critical situations like badlight environment using Visual Teleoperation. In this regardmodeling environments for Humanoid Teleoperation Systemis developed. Here virtual reality modeling environmentincludes development of virtual Humanoid BHR-2, andvirtual objects like table etc. The main goal of this work is toenhance our visual teleoperation system for BHR-2 in orderto avoid any collision during real time operation. SoftwareMaya is used for modeling and simulations. Maya plug-insin VC++ provides efficient modeling rule, real timeinteraction, and time saving rendering approach in a virtualenvironment. In this paper the validity of proposed scheme isshown by conducting experiments using offline step overtrajectory to avoid obstacle in bad light environment.

  16. Jam avoidance with autonomous systems

    OpenAIRE

    Tordeux, Antoine; Lassarre, Sylvain

    2015-01-01

    Many car-following models are developed for jam avoidance in highways. Two mechanisms are used to improve the stability: feedback control with autonomous models and increasing of the interaction within cooperative ones. In this paper, we compare the linear autonomous and collective optimal velocity (OV) models. We observe that the stability is significantly increased by adding predecessors in interaction with collective models. Yet autonomous and collective approaches are close when the speed...

  17. Consumer Privacy and Marketing Avoidance

    OpenAIRE

    Il-Horn Hann; Kai-Lung Hui; Sang-Yong Tom Lee; Ivan Png

    2005-01-01

    We introduce consumer avoidance into analytical marketing research. We show that consumer efforts to conceal themselves and to deflect marketing have a crucial impact on sellers¡¯ marketing strategy. Under reasonable conditions, seller marketing is a strategic complement with consumer concealment. Hence, consumer measures to conceal themselves from marketing will increase its cost-effectiveness and lead sellers to market more. Policies that encourage consumers to conceal their identities woul...

  18. Avoiding congestion in recommender systems

    International Nuclear Information System (INIS)

    Recommender systems use the historical activities and personal profiles of users to uncover their preferences and recommend objects. Most of the previous methods are based on objects’ (and/or users’) similarity rather than on their difference. Such approaches are subject to a high risk of increasingly exposing users to a narrowing band of popular objects. As a result, a few objects may be recommended to an enormous number of users, resulting in the problem of recommendation congestion, which is to be avoided, especially when the recommended objects are limited resources. In order to quantitatively measure a recommendation algorithm's ability to avoid congestion, we proposed a new metric inspired by the Gini index, which is used to measure the inequality of the individual wealth distribution in an economy. Besides this, a new recommendation method called directed weighted conduction (DWC) was developed by considering the heat conduction process on a user–object bipartite network with different thermal conductivities. Experimental results obtained for three benchmark data sets showed that the DWC algorithm can effectively avoid system congestion, and greatly improve the novelty and diversity, while retaining relatively high accuracy, in comparison with the state-of-the-art methods. (paper)

  19. Avoiding unfavourable outcomes in liposuction

    OpenAIRE

    Atul Khanna; George Filobbos

    2013-01-01

    The origin of liposuction can be traced to an adverse event by Dujarrier in 1921 when he used a uterine curette to remove fat from the knees of a ballerina ending in an amputation secondary to damage of the femoral artery. The history of liposuction since then has been one of avoiding complications and optimising outcome. After this adverse event, liposuction was abandoned until the 1960′s when Schrudde revived the practice using small stab incisions and sharp curettage with the secondary suc...

  20. Jam avoidance with autonomous systems

    CERN Document Server

    Tordeux, Antoine

    2016-01-01

    Many car-following models are developed for jam avoidance in highways. Two mechanisms are used to improve the stability: feedback control with autonomous models and increasing of the interaction within cooperative ones. In this paper, we compare the linear autonomous and collective optimal velocity (OV) models. We observe that the stability is significantly increased by adding predecessors in interaction with collective models. Yet autonomous and collective approaches are close when the speed difference term is taking into account. Within the linear OV models tested, the autonomous models including speed difference are sufficient to maximise the stability.

  1. Obstacle-avoiding navigation system

    Science.gov (United States)

    Borenstein, Johann; Koren, Yoram; Levine, Simon P.

    1991-01-01

    A system for guiding an autonomous or semi-autonomous vehicle through a field of operation having obstacles thereon to be avoided employs a memory for containing data which defines an array of grid cells which correspond to respective subfields in the field of operation of the vehicle. Each grid cell in the memory contains a value which is indicative of the likelihood, or probability, that an obstacle is present in the respectively associated subfield. The values in the grid cells are incremented individually in response to each scan of the subfields, and precomputation and use of a look-up table avoids complex trigonometric functions. A further array of grid cells is fixed with respect to the vehicle form a conceptual active window which overlies the incremented grid cells. Thus, when the cells in the active window overly grid cell having values which are indicative of the presence of obstacles, the value therein is used as a multiplier of the precomputed vectorial values. The resulting plurality of vectorial values are summed vectorially in one embodiment of the invention to produce a virtual composite repulsive vector which is then summed vectorially with a target-directed vector for producing a resultant vector for guiding the vehicle. In an alternative embodiment, a plurality of vectors surrounding the vehicle are computed, each having a value corresponding to obstacle density. In such an embodiment, target location information is used to select between alternative directions of travel having low associated obstacle densities.

  2. Adaptive avoidance of reef noise.

    Directory of Open Access Journals (Sweden)

    Stephen D Simpson

    Full Text Available Auditory information is widely used throughout the animal kingdom in both terrestrial and aquatic environments. Some marine species are dependent on reefs for adult survival and reproduction, and are known to use reef noise to guide orientation towards suitable habitat. Many others that forage in food-rich inshore waters would, however, benefit from avoiding the high density of predators resident on reefs, but nothing is known about whether acoustic cues are used in this context. By analysing a sample of nearly 700,000 crustaceans, caught during experimental playbacks in light traps in the Great Barrier Reef lagoon, we demonstrate an auditory capability in a broad suite of previously neglected taxa, and provide the first evidence in any marine organisms that reef noise can act as a deterrent. In contrast to the larvae of species that require reef habitat for future success, which showed an attraction to broadcasted reef noise, taxa with a pelagic or nocturnally emergent lifestyle actively avoided it. Our results suggest that a far greater range of invertebrate taxa than previously thought can respond to acoustic cues, emphasising yet further the potential negative impact of globally increasing levels of underwater anthropogenic noise.

  3. Obesity and Healthcare Avoidance: A Systematic Review

    OpenAIRE

    Robert D McGuigan; Jenny M Wilkinson

    2015-01-01

    This review addresses the issue of health care avoidance and obesity. English language journal articles published between 1990 and 2012 that addressed the review question|“is being overweight or obese an unrecognized factor in healthcare avoidance?” were located using major databases. A modified JADAD scoring system was then used to assess papers. Ten papers were identified which directly addressed the review question. A positive relationship exists between obesity and healthcare avoidance. T...

  4. How Do Speakers Avoid Ambiguous Linguistic Expressions?

    Science.gov (United States)

    Ferreira, V.S.; Slevc, L.R.; Rogers, E.S.

    2005-01-01

    Three experiments assessed how speakers avoid linguistically and nonlinguistically ambiguous expressions. Speakers described target objects (a flying mammal, bat) in contexts including foil objects that caused linguistic (a baseball bat) and nonlinguistic (a larger flying mammal) ambiguity. Speakers sometimes avoided linguistic-ambiguity, and they…

  5. Exact enumeration of self-avoiding walks

    OpenAIRE

    Schram, Raoul D.; Barkema, Gerard T.; Bisseling, Rob H.

    2011-01-01

    A prototypical problem on which techniques for exact enumeration are tested and compared is the enumeration of self-avoiding walks. Here, we show an advance in the methodology of enumeration, making the process thousands or millions of times faster. This allowed us to enumerate self-avoiding walks on the simple cubic lattice up to a length of 36 steps.

  6. Strategic Family Therapy of Avoidant Behavior.

    Science.gov (United States)

    Burgess, Thomas A.; Hinkle, J. Scott

    1993-01-01

    Notes that Millon's biopsychosocial model asserts that socioenvironmental factors of parental or peer rejection may shape development of avoidant behavior but does not elaborate on how family system may perpetuate its existence once disorder has evolved. Presents brief overview of avoidant behavior and strategic family therapy case study.…

  7. Lectures on Self-Avoiding Walks

    OpenAIRE

    Bauerschmidt, Roland; Duminil-Copin, Hugo; Goodman, Jesse; Slade, Gordon

    2012-01-01

    These lecture notes provide a rapid introduction to a number of rigorous results on self-avoiding walks, with emphasis on the critical behaviour. Following an introductory overview of the central problems, an account is given of the Hammersley--Welsh bound on the number of self-avoiding walks and its consequences for the growth rates of bridges and self-avoiding polygons. A detailed proof that the connective constant on the hexagonal lattice equals $\\sqrt{2+\\sqrt{2}}$ is then provided. The la...

  8. End patterns of self-avoiding walks

    International Nuclear Information System (INIS)

    Consider a fixed end pattern (a short self-avoiding walk) that can occur as the first few steps of an arbitrarily long self-avoiding walk on Z/sup d/. It is a difficult open problem to show that as N → ∞, the fraction of N-step self-avoiding walks beginning with this pattern converges. It is shown that as N → ∞, this fraction is bounded away from zero, and that the ratio of the fractions for N and N + 2 converges to one. Similar results are obtained when patterns are specified at both ends, and also when the endpoints are fixed

  9. Passive avoidence learning in the young rat.

    Science.gov (United States)

    Blozovski, D; Cudennec, A

    1980-09-01

    A step-through locomotor passive avoidance task is described requiring the suppression of a spontaneous escape reaction from a cool toward a warm compartment in order to avoid an electric shock delivered in the warm side. We observed no lerning of this task at 9 days of age, a very low but significant level of acquisition at 11 days, a slow but progressive improvement of avoidance from the 13th until the 17th day when the adult capacity was achieved, and a marked increase in the rate between 17-20 days. PMID:7409331

  10. Avoidant/Restrictive Food Intake Disorder

    Science.gov (United States)

    ... Intake Disorder Binge Eating Disorder Bulimia Nervosa Pica Rumination Disorder Avoidant/restrictive food intake disorder is characterized ... Intake Disorder Binge Eating Disorder Bulimia Nervosa Pica Rumination Disorder NOTE: This is the Consumer Version. CONSUMERS: ...

  11. Avoid the Consequences of High Blood Pressure

    Science.gov (United States)

    ... Resources Stroke More Avoid the Consequences of High Blood Pressure Infographic Updated:Jun 19,2014 View a downloadable version of this infographic High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

  12. Dual Eligibles and Potentially Avoidable Hospitalizations

    Data.gov (United States)

    U.S. Department of Health & Human Services — About 25 percent of the hospitalizations for dual eligible beneficiaries in 2005 were potentially avoidable. Medicare and Medicaid spending for those potentially...

  13. Avoiding Anemia: Boost Your Red Blood Cells

    Science.gov (United States)

    ... link, please review our exit disclaimer . Subscribe Avoiding Anemia Boost Your Red Blood Cells If you’re ... and sluggish, you might have a condition called anemia. Anemia is a common blood disorder that many ...

  14. Growing partially directed self-avoiding walks

    OpenAIRE

    Privman, V.

    1985-01-01

    A partially directed self-avoiding walk model with the 'kinetic growth' weighting is solved exactly, on the square lattice and for two restricted, strip geometries. Some finite-size effects are examined.

  15. Family Key to Helping Teens Avoid Obesity

    Science.gov (United States)

    ... 159681.html Family Key to Helping Teens Avoid Obesity Good relationship with parents, especially between fathers and ... develop healthy habits that may protect them against obesity, a new study suggests. The researchers also found ...

  16. How to avoid overheating during exercise

    Science.gov (United States)

    ... patientinstructions/000865.htm How to avoid overheating during exercise To use the sharing features on this page, ... condition can get heat illness. Stay Cool During Exercise Try these tips to help prevent heat-related ...

  17. The challenges for scientists in avoiding plagiarism.

    Science.gov (United States)

    Fisher, E R; Partin, K M

    2014-01-01

    Although it might seem to be a simple task for scientists to avoid plagiarism and thereby an allegation of research misconduct, assessment of trainees in the Responsible Conduct of Research and recent findings from the National Science Foundation Office of Inspector General regarding plagiarism suggests otherwise. Our experiences at a land-grant academic institution in assisting researchers in avoiding plagiarism are described. We provide evidence from a university-wide multi-disciplinary course that understanding how to avoid plagiarism in scientific writing is more difficult than it might appear, and that a failure to learn the rules of appropriate citation may cause dire consequences. We suggest that new strategies to provide training in avoiding plagiarism are required. PMID:24785995

  18. Active Collision Avoidance for Planetary Landers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advancements in radar technology have resulted in commercial, automotive collision avoidance radars. These radar systems typically use 37GHz or 77GHz interferometry...

  19. Conjecture on Avoidance of Big Crunch

    Institute of Scientific and Technical Information of China (English)

    SUN Cheng-Yi; ZHANG De-Hai

    2006-01-01

    By conjecturing the physics at the Planck scale, we modify the definition of the Hawking temperature and modify the Friedmann equation. It is found that we can avoid the singularity of the big crunch and obtain a bouncing cosmological model.

  20. Polymers as Self-Avoiding Walks

    OpenAIRE

    Freed, Karl F.

    1981-01-01

    A brief overview is presented of the relation of the properties of real polymers to the problem of self-avoiding random walks. The self-consistent field method is discussed wherein the non-Markovian continuous self-avoiding polymer is replaced by a self-consistent Markovian approximation. An outline is presented of the method of solution of the resultant nonlinear integrodifferential equations. A description is also presented of the scaling theories which provide a means for deducing some exp...

  1. Weakly prudent self-avoiding bridges

    OpenAIRE

    Bacher, Axel; Beaton, Nicholas,

    2014-01-01

    We define and enumerate a new class of self-avoiding walks on the square lattice, which we call \\emphweakly prudent bridges. Their definition is inspired by two previously-considered classes of self-avoiding walks, and can be viewed as a combination of those two models. We consider several methods for recursively generating these objects, each with its own advantages and disadvantages, and use these methods to solve the generating function, obtain very long series, and randomly generate walks...

  2. Scaling of Self-Avoiding Walks and Self-Avoiding Trails in Three Dimensions

    OpenAIRE

    Prellberg, T.

    2001-01-01

    Motivated by recent claims of a proof that the length scale exponent for the end-to-end distance scaling of self-avoiding walks is precisely $7/12=0.5833...$, we present results of large-scale simulations of self-avoiding walks and self-avoiding trails with repulsive contact interactions on the hypercubic lattice. We find no evidence to support this claim; our estimate $\

  3. Avoiding barriers in control of mowing robot

    Institute of Scientific and Technical Information of China (English)

    QIU Bai-jing; QIAN Guo-hong; XIANG Zhong-ping; LI Zuo-peng

    2006-01-01

    Due to complicated barriers,it is difficult to track the path of the mowing robot and to avoid barriers.In order to solve the problem,a method based on distance-measuring sensors and fuzzy control inputs was proposed.Its track was composed of beelines and was easy to tail.The fuzzy control inputs were based on the front barrier distance and the difference between the left and right barrier distance measured by ultrasonic sensors;the output was the direction angle.The infrared sensors around the robot improved its safety in avoiding barriers.The result of the method was feasible,agile,and stable.The distance between the robot and the barriers could be changed by altering the inputs and outputs of fuzzy control and the length of the beelines.The disposed sensors can fulfill the need of the robot in avoiding barriers.

  4. Avoidable deaths in Greenland 1968-1985

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Juel, K

    1990-01-01

    suicides and alcohol related diseases were high in the capital and East Greenland and low in West Greenlandic settlements. It is concluded that further studies on preventable diseases and causes of death, in particular certain infectious diseases, accidents and suicides, are needed.......The concept of avoidable deaths suggests that certain deaths ought not occur in a given society because it is possible to prevent or treat the disease or condition. A list of avoidable deaths is time and community specific as it reflects the socioeconomic conditions, professional medical capacity...... and political will of the society. A list of avoidable deaths is proposed for Greenland which includes, inter alia, meningitis, lung cancer, acute respiratory infections, suicides, boat accidents and alcohol related diseases and accidents. All were considerably more common in Greenland than in Denmark...

  5. Functional neuroimaging of avoidance habits in OCD

    Science.gov (United States)

    Gillan, Claire M; Apergis-Schoute, Annemieke M; Morein-Zamir, Sharon; Urcelay, Gonzalo P; Sule, Akeem; Fineberg, Naomi A; Sahakian, Barbara J; Robbins, Trevor W

    2016-01-01

    Objective The goal of this study was to determine the neural correlates of excessive habit formation in obsessive-compulsive disorder (OCD). We aimed to (i) test for neurobiological convergence with the known pathophysiology of OCD and (ii) infer, based on abnormalities in brain activation, whether these habits arise from dysfunction in the goal-directed or habit system. Method Thirty-seven OCD patients and 33 controls learned to avoid shocks while undergoing a functional Magnetic Resonance Imaging (fMRI) scan. Following 4 blocks of training, we tested if the avoidance response had become a habit by removing the threat of shock and measuring continued avoidance. We tested for task-related differences in brain activity in 3 ROIs, the caudate, putamen and medial orbitofrontal cortex at a statistical threshold of pdifferences in the build up of stimulus-response habits themselves. PMID:25526600

  6. Autonomous Collision avoidance for Unmanned aerial systems

    OpenAIRE

    Melega, Marco

    2014-01-01

    Unmanned Aerial System (UAS) applications are growing day by day and this will lead Unmanned Aerial Vehicle (UAV) in the close future to share the same airspace of manned aircraft.This implies the need for UAS to define precise safety standards compatible with operations standards for manned aviation. Among these standards the need for a Sense And Avoid (S&A) system to support and, when necessary, sub¬stitute the pilot in the detection and avoidance of hazardous situations (e.g. midair collis...

  7. A collision avoidance system for workpiece protection

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, D.J.; Weber, T.M.; Novak, J.L. [Sandia National Labs., Albuquerque, NM (United States); Maslakowski, J.E. [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.

    1995-04-01

    This paper describes an application of Sandia`s non-contact capacitive sensing technology for collision avoidance during the manufacturing of rocket engine thrust chambers. The collision avoidance system consists of an octagon shaped collar with a capacitive proximity sensor mounted on each face. The sensors produced electric fields which extend several inches from the face of the collar and detect potential collisions between the robot and the workpiece. A signal conditioning system processes the sensor output and provides varying voltage signals to the robot controller for stopping the robot.

  8. Self Organization and Self Avoiding Limit Cycles

    OpenAIRE

    Hexner, Daniel; Levine, Dov

    2014-01-01

    A simple periodically driven system displaying rich behavior is introduced and studied. The system self-organizes into a mosaic of static ordered regions with three possible patterns, which are threaded by one-dimensional paths on which a small number of mobile particles travel. These trajectories are self-avoiding and non-intersecting, and their relationship to self-avoiding random walks is explored. Near $\\rho=0.5$ the distribution of path lengths becomes power-law like up to some cutoff le...

  9. Self-Avoiding Walks with Writhe

    OpenAIRE

    Moroz, J. David; Kamien, Randall D.

    1997-01-01

    We map self-avoiding random walks with a chemical potential for writhe to the three-dimensional complex O(N) Chern-Simons theory as N -> 0. We argue that at the Wilson-Fisher fixed point which characterizes normal self-avoiding walks (with radius of gyration exponent nu = 0.588) a small chemical potential for writhe is irrelevant and the Chern-Simons field does not modify the monomer- monomer correlation function. For a large chemical potential the polymer collapses.

  10. Self-avoiding walks with writhe

    International Nuclear Information System (INIS)

    We map self-avoiding random walks with a chemical potential for writhe to the three-dimensional complex O(N) Chern-Simons theory as N→0. We argue that at the Wilson-Fisher fixed point which characterizes normal self-avoiding walks (with radius of gyration exponent ν∼0.588) a small chemical potential for writhe is irrelevant and the Chern-Simons field does not modify the monomer-monomer correlation function. For a large chemical potential the polymer collapses. (orig.)

  11. Benchmarking Collision Avoidance Schemes for Dynamic Environments

    OpenAIRE

    Martinez-Gomez, Luis; Fraichard, Thierry

    2009-01-01

    This paper evaluates and compare three state-of-the-art collision avoidance schemes designed to operate in dynamic environments. The first one is an extension of the popular Dynamic Window approach; it is henceforth called TVDW which stands for Time-Varying Dynamic Window. The second one called NLVO builds upon the concept of Non Linear Velocity Obstacle which is a generalization of the Velocity Obstacle concept. The last one is called ICS-Avoid, it draws upon the concept of Inevitable Collis...

  12. Beliefs, Anxiety, and Avoiding Failure in Mathematics

    OpenAIRE

    Steve Chinn

    2012-01-01

    Mathematics anxiety has been the subject of several books and numerous research papers, suggesting that it is a significant issue for many people. Children and adults develop strategies to cope with this anxiety, one of which is avoidance. This paper presents data taken from over 2500 mathematics test papers in order to compare the levels of accuracy and the frequency of the use of the “no attempt” strategy, that is, avoidance, for arithmetic problems given to children aged from 10 years to a...

  13. Complications to Avoid with Pre-Diabetes

    Science.gov (United States)

    ... Resources Stroke More Complications to Avoid with Pre-diabetes Updated:Nov 19,2015 If I ignore the ... This content was last reviewed August 2015. Pre-diabetes • Introduction • About Pre-diabetes • What's the Problem? Intro ...

  14. Avoidance Motivation and Conservation of Energy

    NARCIS (Netherlands)

    Roskes, Marieke; Elliot, Andrew J.; Nijstad, Bernard A.; De Dreu, Carsten K. W.

    2013-01-01

    Compared to approach motivation, avoidance motivation evokes vigilance, attention to detail, systematic information processing, and the recruitment of cognitive resources. From a conservation of energy perspective it follows that people would be reluctant to engage in the kind of effortful cognitive

  15. Teaching Preschool Children to Avoid Poison Hazards

    Science.gov (United States)

    Dancho, Kelly A.; Thompson, Rachel H.; Rhoades, Melissa M.

    2008-01-01

    We evaluated the effectiveness of group safety training and in situ feedback and response interruption to teach preschool children to avoid consuming potentially hazardous substances. Three children ingested ambiguous substances during a baited baseline assessment condition and continued to ingest these substances following group safety training.…

  16. Organising European technical documentation to avoid duplication.

    Science.gov (United States)

    Donawa, Maria

    2006-04-01

    The development of comprehensive accurate and well-organised technical documentation that demonstrates compliance with regulatory requirements is a resource-intensive, but critically important activity for medical device manufacturers. This article discusses guidance documents and method of organising technical documentation that may help avoid costly and time-consuming duplication. PMID:16736662

  17. Reasonable Avoidability, Responsibility and Lifestyle Diseases

    DEFF Research Database (Denmark)

    Andersen, Martin Marchman

    2012-01-01

    In “Health, Luck and Justice” Shlomi Segall argues for a luck egalitarian approach to justice in health care. As the basis for a just distribution he suggests a principle of Reasonable Avoidability, which he takes to imply that we do not have justice-based reasons to treat diseases brought about ...

  18. Your Adolescent: Anxiety and Avoidant Disorders

    Science.gov (United States)

    ... the problem manifests in school avoidance, the initial goal will be to get the youngster back to school as soon as possible. Cognitive-Behavioral Therapy In many cases, cognitive-behavioral psychotherapy techniques are effective in addressing adolescent anxiety disorders. ...

  19. Pathogen evolution under host avoidance plasticity.

    Science.gov (United States)

    McLeod, David V; Day, Troy

    2015-09-01

    Host resistance consists of defences that limit pathogen burden, and can be classified as either adaptations targeting recovery from infection or those focused upon infection avoidance. Conventional theory treats avoidance as a fixed strategy which does not vary from one interaction to the next. However, there is increasing empirical evidence that many avoidance strategies are triggered by external stimuli, and thus should be treated as phenotypically plastic responses. Here, we consider the implications of avoidance plasticity for host-pathogen coevolution. We uncover a number of predictions challenging current theory. First, in the absence of pathogen trade-offs, plasticity can restrain pathogen evolution; moreover, the pathogen exploits conditions in which the host would otherwise invest less in resistance, causing resistance escalation. Second, when transmission trades off with pathogen-induced mortality, plasticity encourages avirulence, resulting in a superior fitness outcome for both host and pathogen. Third, plasticity ensures the sterilizing effect of pathogens has consequences for pathogen evolution. When pathogens castrate hosts, selection forces them to minimize mortality virulence; moreover, when transmission trades off with sterility alone, resistance plasticity is sufficient to prevent pathogens from evolving to fully castrate. PMID:26336170

  20. Learn to Avoid or Overcome Leadership Obstacles

    Science.gov (United States)

    D'Auria, John

    2015-01-01

    Leadership is increasingly recognized as an important factor in moving schools forward, yet we have been relatively random in how we prepare and support them. Four obstacles often block or diminish their effectiveness. Avoiding or overcoming each of these requires an underlying set of skills and knowledge that we believe can be learned and…

  1. The Advocacy or Avoidance of Only Children.

    Science.gov (United States)

    Falbo, Toni

    A brief review of the psychological literature on the characteristics of only children is presented in order to determine if the one-child family should be avoided or advocated. The relevant literature is found to be limited in quantity and conceptualization of the only child. Previous literature is divided into three types of study: those with…

  2. Bilocal Dynamics for Self-Avoiding Walks

    CERN Document Server

    Caracciolo, Sergio; Ferraro, G; Papinutto, Mauro; Pelissetto, A; Caracciolo, Sergio; Causo, Maria Serena; Ferraro, Giovanni; Papinutto, Mauro; Pelissetto, Andrea

    2000-01-01

    We introduce several bilocal algorithms for lattice self-avoiding walks that provide reasonable models for the physical kinetics of polymers in the absence of hydrodynamic effects. We discuss their ergodicity in different confined geometries, for instance in strips and in slabs. A short discussion of the dynamical properties in the absence of interactions is given.

  3. Self-avoiding random walk in superspace

    International Nuclear Information System (INIS)

    The model is presented, where all the critical exponents are calculated exactly. It corresponds to a self-avoiding random walk in superspace of dimension D≤4. For the correlation length the validity of Flory's conjecture (ν=3/(D+2)) is confirmed. (orig.)

  4. Bilocal Dynamics for Self-Avoiding Walks

    OpenAIRE

    Caracciolo, Sergio; Causo, Maria Serena; Ferraro, Giovanni; Papinutto, Mauro; Pelissetto, Andrea

    1999-01-01

    We introduce several bilocal algorithms for lattice self-avoiding walks that provide reasonable models for the physical kinetics of polymers in the absence of hydrodynamic effects. We discuss their ergodicity in different confined geometries, for instance in strips and in slabs. A short discussion of the dynamical properties in the absence of interactions is given.

  5. Specific Language Impairment at Adolescence: Avoiding Complexity

    Science.gov (United States)

    Tuller, Laurice; Henry, Celia; Sizaret, Eva; Barthez, Marie-Anne

    2012-01-01

    This study explores complex language in adolescents with specific language impairment (SLI) with the aim of finding out how aspects of language characteristic of typical syntactic development after childhood fare and, in particular, whether there is evidence that individuals with SLI avoid using structures whose syntactic derivation involves…

  6. Working with Avoidant Children: A Clinical Challenge.

    Science.gov (United States)

    Berson, Nancy; Meisburger, Diana

    1998-01-01

    Presents strategies for interviewing and assisting highly avoidant children who may be victims of maltreatment. Discusses factors inhibiting their self-disclosure, the importance of managing child safety, and establishing and maintaining rapport. Describes strategies including pacing the interview, empowering the child, and using distancing…

  7. Obesity and Healthcare Avoidance: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Robert D McGuigan

    2015-03-01

    Full Text Available This review addresses the issue of health care avoidance and obesity. English language journal articles published between 1990 and 2012 that addressed the review question|“is being overweight or obese an unrecognized factor in healthcare avoidance?” were located using major databases. A modified JADAD scoring system was then used to assess papers. Ten papers were identified which directly addressed the review question. A positive relationship exists between obesity and healthcare avoidance. The major contributory factors were being female, have a diagnosed mental health problem and perceived or actual bias and discrimination by health professionals. The review also highlights the importance of the relationship between healthcare professionals and their patients, and the physical environment in which interactions occur as these may contribute to avoidance behaviors. Concern about obesity is rising and while there has been much discussion about strategies to reduce obesity this review highlights the need for thinking more broadly about the way in which overweight and obese individuals interact with preventative health strategies.

  8. Obsessive compulsive disorder with pervasive avoidance

    OpenAIRE

    Sharma Parul; Sharma Ravi; Kumar Ramesh; Sharma Dinesh

    2009-01-01

    Obsessive compulsive disorder (OCD) is a common disorder, but some of its atypical presentations are uncommon and difficult to diagnose. We report one such case which on initial presentation appeared to be psychotic protocol but after detailed workup was diagnosed as OCD with marked avoidance symptoms.

  9. Doppler micro sense and avoid radar

    Science.gov (United States)

    Gorwara, Ashok; Molchanov, Pavlo; Asmolova, Olga

    2015-10-01

    There is a need for small Sense and Avoid (SAA) systems for small and micro Unmanned Aerial Systems (UAS) to avoid collisions with obstacles and other aircraft. The proposed SAA systems will give drones the ability to "see" close up and give them the agility to maneuver through tight areas. Doppler radar is proposed for use in this sense and avoid system because in contrast to optical or infrared (IR) systems Doppler can work in more harsh conditions such as at dusk, and in rain and snow. And in contrast to ultrasound based systems, Doppler can better sense small sized obstacles such as wires and it can provide a sensing range from a few inches to several miles. An SAA systems comprised of Doppler radar modules and an array of directional antennas that are distributed around the perimeter of the drone can cover the entire sky. These modules are designed so that they can provide the direction to the obstacle and simultaneously generate an alarm signal if the obstacle enters within the SAA system's adjustable "Protection Border". The alarm signal alerts the drone's autopilot to automatically initiate an avoidance maneuver. A series of Doppler radar modules with different ranges, angles of view and transmitting power have been designed for drones of different sizes and applications. The proposed Doppler radar micro SAA system has simple circuitry, works from a 5 volt source and has low power consumption. It is light weight, inexpensive and it can be used for a variety of small unmanned aircraft.

  10. Measuring Patients’ Attachment Avoidance in Psychotherapy: Development of the Attachment Avoidance in Therapy Scale (AATS

    Directory of Open Access Journals (Sweden)

    András Láng

    2012-11-01

    Full Text Available A new scale measuring patient-therapist attachment avoidance was developed. Attachment Avoidance in Therapy Scale is a new measure based on the Bartholomew model of adult attachment (Bartholomew & Horowitz, 1991 and the Experience in Close Relationships Scale (Brennan, Clark, & Shaver, 1998 to measure patients’ attachment avoidance towards therapists. With 112 patient-therapist dyads participating in the study, validation of a preliminary scale – measuring both attachment anxiety and attachment avoidance in therapy – took place using therapists’ evaluations of patients’ relational behavior and patients’ self-reports about their attitude toward psychotherapy. Analysis of the data revealed six underlying scales. Results showed all six scales to be reliable. Validation of scales measuring attachment anxiety failed. The importance of Attachment Avoidance in Therapy Scale and its subscales is discussed.

  11. Bursting neurons and ultrasound avoidance in crickets

    Directory of Open Access Journals (Sweden)

    Gary eMarsat

    2012-07-01

    Full Text Available Decision making in invertebrates often relies on simple neural circuits composed of only a few identified neurons. The relative simplicity of these circuits makes it possible to identify the key computation and neural properties underlying decisions. In this review, we summarize recent research on the neural basis of ultrasound avoidance in crickets, a response that allows escape from echolocating bats. The key neural property shaping behavioral output is high-frequency bursting of an identified interneuron, AN2, which carries information about ultrasound stimuli from receptor neurons to the brain. AN2's spike train consists of clusters of spikes –bursts– that may be interspersed with isolated, non-burst spikes. AN2 firing is necessary and sufficient to trigger avoidance steering but only high-rate firing, such as occurs in bursts, evokes this response. AN2 bursts are therefore at the core of the computation involved in deciding whether or not to steer away from ultrasound. Bursts in AN2 are triggered by synaptic input from nearly synchronous bursts in ultrasound receptors. Thus the population response at the very first stage of sensory processing –the auditory receptor- already differentiates the features of the stimulus that will trigger a behavioral response from those that will not. Adaptation, both intrinsic to AN2 and within ultrasound receptors, scales the burst-generating features according to the stimulus statistics, thus filtering out background noise and ensuring that bursts occur selectively in response to salient peaks in ultrasound intensity. Furthermore AN2’s sensitivity to ultrasound varies adaptively with predation pressure, through both developmental and evolutionary mechanisms. We discuss how this key relationship between bursting and the triggering of avoidance behavior is also observed in other invertebrate systems such as the avoidance of looming visual stimuli in locusts or heat avoidance in beetles.

  12. The Feasibility of Avoiding Future Climate Impacts: Results from the AVOID Programmes

    Science.gov (United States)

    Lowe, J. A.; Warren, R.; Arnell, N.; Buckle, S.

    2014-12-01

    The AVOID programme and its successor, AVOID2, have focused on answering three core questions: how do we characterise potentially dangerous climate change and impacts, which emissions pathways can avoid at least some of these impacts, and how feasible are the future reductions needed to significantly deviate from a business-as-usual future emissions pathway. The first AVOID project succeeded in providing the UK Government with evidence to inform its position on climate change. A key part of the work involved developing a range of global emissions pathways and estimating and understanding the corresponding global impacts. This made use of a combination of complex general circulation models, simple climate models, pattern-scaling and state-of-the art impacts models. The results characterise the range of avoidable impacts across the globe in several key sectors including river and coastal flooding, cooling and heating energy demand, crop productivity and aspects of biodiversity. The avoided impacts between a scenario compatible with a 4ºC global warming and one with a 2ºC global warming were found to be highly sector dependent and avoided fractions typically ranged between 20% and 70%. A further key aspect was characterising the magnitude of the uncertainty involved, which is found to be very large in some impact sectors although the avoided fraction appears a more robust metric. The AVOID2 programme began in 2014 and will provide results in the run up to the Paris CoP in 2015. This includes new post-IPCC 5th assessment evidence to inform the long-term climate goal, a more comprehensive assessment of the uncertainty ranges of feasible emission pathways compatible with the long-term goal and enhanced estimates of global impacts using the latest generation of impact models and scenarios.

  13. UV Impacts Avoided by the Montreal Protocol

    Science.gov (United States)

    Newman, Paul; McKenzie, Richard

    2010-01-01

    Temporal and geographical variabilities in the future "World Expected" UV environment are compared with the "World Avoided", which would have occurred without the Montreal Protocol on protection of the ozone layer and its subsequent amendments and adjustments. Based on calculations of clear-sky UV irradiances, the effects of the Montreal Protocol have been hugely beneficial to avoid the health risks, such as skin cancer, which are associated with high UV, while there is only a small increase in health risks, such as vitamin D deficiency, that are associated with low UV. However, interactions with climate change may lead to changes in cloud and albedo, and possibly behavioural changes which could also be important.

  14. How to avoid deferred-compensation troubles.

    Science.gov (United States)

    Freeman, Todd I

    2005-06-01

    Executive compensation packages have long included stock options and deferred compensation plans in order to compete for talent. Last year, Congress passed a law in response to the Enron debacle, in which executives were perceived to be protecting their deferred compensation at the expense of employees, creditors, and investors. The new law is designed to protect companies and their shareholders from being raided by the very executives that guided the company to financial ruin. Physicians who are part owners of medical practices need to know about the changes in the law regarding deferred compensation and how to avoid costly tax penalties. This article discusses how the changes affect medical practices as well as steps physician-owned clinics can take to avoid the risk of penalty, such as freezing deferred compensation and creating a new deferred compensation plan. PMID:16050311

  15. Construction dispute research conceptualisation, avoidance and resolution

    CERN Document Server

    2014-01-01

    There are three specific purposes of Construction Dispute Research. First, this volume aims to summarise studies on construction dispute. Second, apart from the theoretical constructs, where appropriate empirical tests are also included. This approach serves to go beyond the commonly used anecdotal approach for the subject matters. Third, it is the sincere hope of the authors that this book will help shaping research agenda of construction dispute.  The studies are mostly framed from a management perspective drawing on methods and concepts in contract law, economics, psychology and management science.   The book has twenty chapters that are arranged in four parts covering conceptualisation, avoidance, negotiation and mediation. Part 1 is devoted for dispute conceptualisation. A building is only as strong as its foundation. Thus it is no better start to study construction dispute by conceptualisation. The theme of Part 2 is dispute avoidance. The conventional wisdom of ‘prevention is better than cure’ se...

  16. Obstacle Detection and Avoidance Autonomous Car

    OpenAIRE

    K.Vasavi; M.V.S.Praveen

    2014-01-01

    Driving models are needed by many researchers to improve traffic safety and to advance autonomous vehicle design. To be most useful, a driving model must state specifically what information is needed and how it is processed. So we developed an “Obstacle Avoidance and Detection Autonomous Car” based on sensor application. The essential part of this autonomous car is that it drives taking the energy from solar panel. This paper explains the method of interfacing the solar panel, relay circuit b...

  17. Anorexia nervosa and food avoidance emotional disorder.

    OpenAIRE

    Higgs, J F; Goodyer, I M; Birch, J.

    1989-01-01

    A retrospective and longitudinal study was carried out on all children and adolescents who presented to a child psychiatry service over a period of 26 years to identify the nature, course, and outcome of cases meeting criteria for anorexia nervosa (n = 27). Two groups of the same age were identified for comparison, firstly those with food avoidance and emotional disorders (n = 23), and secondly those with emotional disorders but no symptoms associated with eating (n = 22). The results confirm...

  18. Robot maps, robot moves, robot avoids

    OpenAIRE

    Farrugia, Claire; Duca, Edward

    2014-01-01

    Robotics is a cornerstone for this century’s innovations. From robot nurses to your own personal assistant, most robots need to know: ‘where is it?’ ‘Where should it go?’ And ‘how to get there?’ Without answers to these questions a robot cannot do much. http://www.um.edu.mt/think/robot-maps-robot-moves-robot-avoids/

  19. Can subjectivity be avoided in translation evaluation?

    OpenAIRE

    Segers, Winibert; Kockaert, Hendrik

    2015-01-01

    The didactics of translation and interpreting Testing and assessment criteria and methods Can subjectivity be avoided in translation evaluation? Winibert Segers & Hendrik J Kockaert, KU Leuven Camiel Paulusstraat 8, 2630 Aartselaar, België Is translation evaluation a subjective, personal matter? Is evaluating translations the same as beer tasting or listening to a piece of music? Is the judgment determined by personal taste? We will try to answe...

  20. Inhibited Sexual Desire and Sexual Avoidance

    OpenAIRE

    Morse, William I.

    1985-01-01

    Inhibited sexual desire (ISD) is one of the most common sexual dysfunctions, especially in women. Family physicians have an opportunity to recognize ISD before the associated problems become entrenched, and to guide couples toward satisfactory resolution. A summary is presented of current thinking on ISD and its causes. Case reports and observations about frequency of and treatment for ISD are included. Much less has been written about sexual avoidance in the presence of desire. A definition ...

  1. Normal coronary arteriogram. An avoidable test?

    OpenAIRE

    Ilsley, C; Stockley, A; Clitsakis, D; Layton, C

    1982-01-01

    Between 10 and 20% of coronary arteriograms in patients with chest pain show normal vessels, often in association with a history of "atypical" angina. Conventional non-invasive tests are inaccurate in this group of patients compared with those with classical angina. This study prospectively evaluates combined 12 lead exercise electrocardiography and thallium-201 scintigraphy as a screening test in patients with atypical angina in order to determine whether normal arteriograms are avoidable in...

  2. Airborne Collision Detection and Avoidance for Small UAS Sense and Avoid Systems

    Science.gov (United States)

    Sahawneh, Laith Rasmi

    The increasing demand to integrate unmanned aircraft systems (UAS) into the national airspace is motivated by the rapid growth of the UAS industry, especially small UAS weighing less than 55 pounds. Their use however has been limited by the Federal Aviation Administration regulations due to collision risk they pose, safety and regulatory concerns. Therefore, before civil aviation authorities can approve routine UAS flight operations, UAS must be equipped with sense-and-avoid technology comparable to the see-and-avoid requirements for manned aircraft. The sense-and-avoid problem includes several important aspects including regulatory and system-level requirements, design specifications and performance standards, intruder detecting and tracking, collision risk assessment, and finally path planning and collision avoidance. In this dissertation, our primary focus is on developing an collision detection, risk assessment and avoidance framework that is computationally affordable and suitable to run on-board small UAS. To begin with, we address the minimum sensing range for the sense-and-avoid (SAA) system. We present an approximate close form analytical solution to compute the minimum sensing range to safely avoid an imminent collision. The approach is then demonstrated using a radar sensor prototype that achieves the required minimum sensing range. In the area of collision risk assessment and collision prediction, we present two approaches to estimate the collision risk of an encounter scenario. The first is a deterministic approach similar to those been developed for Traffic Alert and Collision Avoidance (TCAS) in manned aviation. We extend the approach to account for uncertainties of state estimates by deriving an analytic expression to propagate the error variance using Taylor series approximation. To address unanticipated intruders maneuvers, we propose an innovative probabilistic approach to quantify likely intruder trajectories and estimate the probability of

  3. Urban water restrictions: Attitudes and avoidance

    Science.gov (United States)

    Cooper, Bethany; Burton, Michael; Crase, Lin

    2011-12-01

    In most urban cities across Australia, water restrictions remain the dominant policy mechanism to restrict urban water consumption. The extensive adoption of water restrictions as a means to limit demand, over several years, means that Australian urban water prices have consistently not reflected the opportunity cost of water. Given the generally strong political support for water restrictions and the likelihood that they will persist for some time, there is value in understanding households' attitudes in this context. More specifically, identifying the welfare gains associated with avoiding urban water restrictions entirely would be a nontrivial contribution to our knowledge and offer insights into the benefits of alternative policy responses. This paper describes the results from a contingent valuation study that investigates consumers' willingness to pay to avoid urban water restrictions. Importantly, the research also investigates the influence of cognitive and exogenous dimensions on the utility gain associated with avoiding water restrictions. The results provide insights into the impact of the current policy mechanism on economic welfare.

  4. Granting silence to avoid wireless collisions

    KAUST Repository

    Choi, Jung Il

    2010-10-01

    We describe grant-to-send, a novel collision avoidance algorithm for wireless mesh networks. Rather than announce packets it intends to send, a node using grant-to-send announces packets it expects to hear others send. We present evidence that inverting collision avoidance in this way greatly improves wireless mesh performance. Evaluating four protocols from 802.11 meshes and 802.15.4 sensor networks, we find that grant-to-send matches or outperforms CSMA and RTS/CTS in all cases. For example, in a 4-hop UDP flow, grantto- send can achieve 96% of the theoretical maximum throughput while maintaining a 99.9% packet delivery ratio. Grant-tosend is also general enough to replace protocol-specific collision avoidance mechanisms common to sensor network protocols. Grant-to-send is simple. For example, incorporating it into 802.11 requires only 11 lines of driver code and no hardware changes. Furthermore, as it reuses existing 802.11 mechanisms, grant-to-send inter-operates with current networks and can be incrementally deployed. © 2010 IEEE.

  5. Traffic jam driving with NMV avoidance

    Science.gov (United States)

    Milanés, Vicente; Alonso, Luciano; Villagrá, Jorge; Godoy, Jorge; de Pedro, Teresa; Oria, Juan P.

    2012-08-01

    In recent years, the development of advanced driver assistance systems (ADAS) - mainly based on lidar and cameras - has considerably improved the safety of driving in urban environments. These systems provide warning signals for the driver in the case that any unexpected traffic circumstance is detected. The next step is to develop systems capable not only of warning the driver but also of taking over control of the car to avoid a potential collision. In the present communication, a system capable of autonomously avoiding collisions in traffic jam situations is presented. First, a perception system was developed for urban situations—in which not only vehicles have to be considered, but also pedestrians and other non-motor-vehicles (NMV). It comprises a differential global positioning system (DGPS) and wireless communication for vehicle detection, and an ultrasound sensor for NMV detection. Then, the vehicle's actuators - brake and throttle pedals - were modified to permit autonomous control. Finally, a fuzzy logic controller was implemented capable of analyzing the information provided by the perception system and of sending control commands to the vehicle's actuators so as to avoid accidents. The feasibility of the integrated system was tested by mounting it in a commercial vehicle, with the results being encouraging.

  6. See-and-Avoid Collision Avoidance Using ADS-B Signal and Radar Sensing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — IAI proposes an innovative collision avoidance radar and communication technology to detect and track both cooperative and non-cooperative targets. The system...

  7. Avoiding Negative Outcomes: Tracking the Mechanisms of Avoidance Learning in Humans During Fear Conditioning

    OpenAIRE

    Delgado, Mauricio R.; Jou, Rita L.; Liz Phelps

    2009-01-01

    Previous research across species has shown that the amygdala is critical for learning about aversive outcomes, while the striatum is involved in reward-related processing. Less is known, however, about the role of the amygdala and the striatum in learning how to exert control over emotions and avoid negative outcomes. One potential mechanism for active avoidance of stressful situations is postulated to involve amygdala–striatal interactions. The goal of this study was to investigate the physi...

  8. Avoiding negative outcomes: tracking the mechanisms of avoidance learning in humans during fear conditioning

    Directory of Open Access Journals (Sweden)

    Mauricio R Delgado

    2009-11-01

    Full Text Available Previous research across species has shown that the amygdala is critical for learning about aversive outcomes, while the striatum is involved in reward-related processing. Less is known, however, about the role of the amygdala and the striatum in learning how to exert control over emotions and avoid negative outcomes. One potential mechanism for active avoidance of stressful situations is postulated to involve amygdala-striatal interactions. The goal of this study was to investigate the physiological and neural correlates underlying avoidance learning in humans. Specifically, we used a classical conditioning paradigm where three different conditioned stimuli (CS were presented. One stimulus predicted the delivery of a shock upon stimulus offset (CS+, while another predicted no negative consequences (CS-. A third conditioned cue also predicted delivery of a shock, but participants were instructed that upon seeing this stimulus, they could avoid the shock if they chose the correct action (AV +. After successful learning, participants could then easily terminate the shock during subsequent stimulus presentations (AV-. Physiological responses (as measured by SCRs confirmed a main effect of conditioning, particularly showing higher arousal responses during pre (AV+ compared to post (AV- learning of an avoidance response. Consistent with animal models, amygdala-striatal interactions were observed to underlie the acquisition of an avoidance response. These results support a mechanism of active coping with conditioned fear that allows for the control over emotional responses such as fears that can become maladaptive and influence our decision-making.

  9. The global cost of eliminating avoidable blindness

    Directory of Open Access Journals (Sweden)

    Kirsten L Armstrong

    2012-01-01

    Full Text Available Aims : To complete an initial estimate of the global cost of eliminating avoidable blindness, including the investment required to build ongoing primary and secondary health care systems, as well as to eliminate the ′backlog′ of avoidable blindness. This analysis also seeks to understand and articulate where key data limitations lie. Materials and Methods : Data were collected in line with a global estimation approach, including separate costing frameworks for the primary and secondary care sectors, and the treatment of backlog. Results : The global direct health cost to eliminate avoidable blindness over a 10-year period from 2011 to 2020 is estimated at $632 billion per year (2009 US$. As countries already spend $592 billion per annum on eye health, this represents additional investment of $397.8 billion over 10 years, which is $40 billion per year or $5.80 per person for each year between 2010 and 2020. This is concentrated in high-income nations, which require 68% of the investment but comprise 16% of the world′s inhabitants. For all other regions, the additional investment required is $127 billion. Conclusions : This costing estimate has identified that low- and middle-income countries require less than half the additional investment compared with high-income nations. Low- and middle-income countries comprise the greater investment proportion in secondary care whereas high-income countries require the majority of investment into the primary sector. However, there is a need to improve sector data. Investment in better data will have positive flow-on effects for the eye health sector.

  10. CORPORATE SOCIAL RESPONSIBILITY VERSUS TAX AVOIDANCE PRACTICES

    Directory of Open Access Journals (Sweden)

    Stoian Ciprian-Dumitru

    2012-07-01

    Full Text Available Worldwide crisis has made multinational companies that are engaged in corporate social responsibility actions to manage their businesses through the lens of various tax avoidance practices. The content of this paper is important due to the fact that tries to identify the impact in case of companies active in corporate social responsibility actions versus their tax structures orientation. Corporate social responsibility literature did not paid enough attention on the impact of the tax avoidance practices of companies. Tax, as a concept, brings in itself an important corporate financial impact with subsequent effects for the life of multiple citizens in countries where private entities are operating. Even though companies are usually expressing their ethical and responsible conduct in respect of the social environment, there are many cases when the business practices were not aligned with the declared corporate behavior. This paper seeks firstly to examine whether companies engaged in tax avoidance practices (ex. offshore tax havens consider that continue to act socially responsible. Secondly, the paper examines the influence on attending the stakeholders’ goals for those companies practicing tax avoidance and its implications on corporate social responsibility actions. Moreover, the paper focuses also on the aspects described before from the perspective of the corporate entities operating in Romania. This paper’s intention is to use and to develop the results of previous research carried out by Lutz Preus (University of London and, subsequently, by Senators Levin, Coleman and Obama in their “Stop Tax Haven Abuse Bill”. The implications and the objectives of this material are to highlight, to identify and to spot clearly the relations and the influences of the tax haven practices of corporations versus their undertaken social responsibility actions. Moreover, this paper brings a fresh perspective of this topic from the

  11. Wireless vehicular networks for car collision avoidance

    CERN Document Server

    2013-01-01

    Wireless Vehicular Networks for Car Collision Avoidance focuses on the development of the ITS (Intelligent Transportation Systems) in order to minimize vehicular accidents. The book presents and analyses a range of concrete accident scenarios while examining the causes of vehicular collision and proposing countermeasures based on wireless vehicular networks. The book also describes the vehicular network standards and quality of service mechanisms focusing on improving critical dissemination of safety information. With recommendations on techniques and protocols to consider when improving road safety policies in order to minimize crashes and collision risks.

  12. The International Double Taxation – Avoiding Methods

    Directory of Open Access Journals (Sweden)

    Nicoleta Barbuta-Misu

    2009-06-01

    Full Text Available The paper presents the main causes that determine double taxation, its forms, i.e. the economicdouble taxation and the international legal double taxation, the need for eliminating the double taxation andavoiding methods. In the presentation of the avoidance methods have been used practical examples forcomparison of the tax advantages for income beneficiary between: the total exemption method andprogressive exemption method, on the one hand, and total crediting method and ordinary crediting method,on the other hand, but the comparing of tax reduction between methods of exemption and crediting.

  13. Understanding, Avoiding, and Managing Severe Filler Complications.

    Science.gov (United States)

    Rzany, Berthold; DeLorenzi, Claudio

    2015-11-01

    Any injectable filler may elicit moderate-to-severe adverse events, ranging from nodules to abscesses to vascular occlusion. Fortunately, severe adverse events are uncommon for the majority of fillers currently on the market. Because these are rare events, it is difficult to identify the relevant risk factors and to design the most efficacious treatment strategies. Poor aesthetic outcomes are far more common than severe adverse events. These in contrast should be easily avoidable by ensuring that colleagues receive proper training and follow best practices. PMID:26441099

  14. Families of prudent self-avoiding walks

    OpenAIRE

    Bousquet-Mélou, Mireille

    2010-01-01

    A self-avoiding walk (SAW) on the square lattice is prudent if it never takes a step towards a vertex it has already visited. Prudent walks differ from most classes of SAW that have been counted so far in that they can wind around their starting point. Their enumeration was first addressed by Préa in 1997. He defined 4 classes of prudent walks, of increasing generality, and wrote a system of recurrence relations for each of them . However, these relations involve more and more parameters as t...

  15. How to avoid unnatural hierarchical thermal leptogenesis

    CERN Document Server

    Clarke, Jackson D

    2015-01-01

    A one-flavour naturalness argument suggests that the Type I seesaw model cannot naturally explain neutrino masses and the baryon asymmetry of the Universe via hierarchical thermal leptogenesis. We prove that there is no way to avoid this conclusion in a minimal three-flavour setup. We then comment on the simplest ways out. In particular, we focus on a resolution utilising a second Higgs doublet. Such models predict an automatically SM-like Higgs boson, (maximally) TeV-scale scalar states, and low- to intermediate-scale hierarchical leptogenesis with $10^3\\text{ GeV}\\lesssim M_{N_1}\\lesssim 10^7\\text{ GeV}$.

  16. Avoiding plagiarism: guidance for nursing students.

    Science.gov (United States)

    Price, Bob

    The pressures of study, diversity of source materials, past assumptions relating to good writing practice, ambiguous writing guidance on best practice and students' insecurity about their reasoning ability, can lead to plagiarism. With the use of source checking software, there is an increased chance that plagiarised work will be identified and investigated, and penalties given. In extreme cases, plagiarised work may be reported to the Nursing and Midwifery Council and professional as well as academic penalties may apply. This article provides information on how students can avoid plagiarism when preparing their coursework for submission. PMID:24568425

  17. Avoidance learning : a review of theoretical models and recent developments

    OpenAIRE

    Krypotos, Angelos-Miltiadis; Effting, Marieke; Kindt, Merel; Beckers, Tom

    2015-01-01

    Avoidance is a key characteristic of adaptive and maladaptive fear. Here, we review past and contemporary theories of avoidance learning. Based on the theories, experimental findings and clinical observations reviewed, we distill key principles of how adaptive and maladaptive avoidance behavior is acquired and maintained. We highlight clinical implications of avoidance learning theories and describe intervention strategies that could reduce maladaptive avoidance and prevent its return. We end...

  18. Avoidance Learning: A Review of Theoretical Models and Recent Developments

    OpenAIRE

    Angelos-Miltiadis Krypotos; Tom Beckers

    2015-01-01

    Avoidance is a key characteristic of adaptive and maladaptive fear. Here, we review past and contemporary theories of avoidance learning. Based on the theories, experimental findings and clinical observations reviewed, we distil key principles of how adaptive and maladaptive avoidance behavior is acquired and maintained. We highlight clinical implications of avoidance learning theories and describe intervention strategies that could reduce maladaptive avoidance and prevent its return. We e...

  19. Avoidance of strobe lights by zooplankton

    Science.gov (United States)

    Hamel, Martin J.; Richards, Nathan S.; Brown, Michael L.; Chipps, Steven R.

    2010-01-01

    Underwater strobe lights can influence the behavior and distribution of fishes and are increasingly used as a technique to divert fish away from water intake structures on dams. However, few studies examine how strobe lights may affect organisms other than targeted species. To gain insight on strobe lighting effects on nontarget invertebrates, we investigated whether underwater strobe lights influence zooplankton distributions and abundance in Lake Oahe, South Dakota. Zooplankton were collected using vertical tows at 3 discrete distances from an underwater strobe light to quantify the influence of light intensity on zooplankton density. Samples were collected from 3 different depth ranges (0–10 m, 10–20 m and 20–30 m) at zooplankton sampled from 17 August to 15 September 2004. Night time zooplankton densities significantly decreased in surface waters when strobe lights were activated. Copepods exhibited the greatest avoidance patterns, while Daphnia avoidance varied throughout sampling depths. These results indicate that zooplankton display negative phototaxic behavior to strobe lights and that researchers must be cognizant of potential effects to the ecosystem such as altering predator–prey interactions or affecting zooplankton distribution and growth.

  20. Shape optimization of self-avoiding curves

    Science.gov (United States)

    Walker, Shawn W.

    2016-04-01

    This paper presents a softened notion of proximity (or self-avoidance) for curves. We then derive a sensitivity result, based on shape differential calculus, for the proximity. This is combined with a gradient-based optimization approach to compute three-dimensional, parameterized curves that minimize the sum of an elastic (bending) energy and a proximity energy that maintains self-avoidance by a penalization technique. Minimizers are computed by a sequential-quadratic-programming (SQP) method where the bending energy and proximity energy are approximated by a finite element method. We then apply this method to two problems. First, we simulate adsorbed polymer strands that are constrained to be bound to a surface and be (locally) inextensible. This is a basic model of semi-flexible polymers adsorbed onto a surface (a current topic in material science). Several examples of minimizing curve shapes on a variety of surfaces are shown. An advantage of the method is that it can be much faster than using molecular dynamics for simulating polymer strands on surfaces. Second, we apply our proximity penalization to the computation of ideal knots. We present a heuristic scheme, utilizing the SQP method above, for minimizing rope-length and apply it in the case of the trefoil knot. Applications of this method could be for generating good initial guesses to a more accurate (but expensive) knot-tightening algorithm.

  1. Collision avoidance for CTV: Requirements and capabilities

    Science.gov (United States)

    Nosek, Thomas P.

    Cargo transfer vehicle (CTV) operations near Space Station Freedom will require positive collision avoidance maneuver (CAM) capability to preclude any change of collision, even in the event of CTV failures. The requirements for CAM are discussed, and the CAM design approach and design of the Orbiting Maneuvering Vehicle (OMV) are reviewed; this design met requirements for OMV operation near the Space Station, provided a redundant collision avoidance maneuver capability. Significant portions of the OMV CAM design should be applicable to CTV. The key features of the OMV design are summarized and related to the CTV mission design to that of OMV's. CAM is a defined sequence of events executed by the CTV to place the vehicle in a safe position relative to a target such as the Space Station. CAM can be performed through software commands to the propulsion system, or through commands pre-stored in hardware. Various techniques for triggering CAM are considered, and the risks associated with CAM enable and execution in phases are considered. OMV CAM design features both hardware and software CAM capability, with analyses conducted to assess the ability to meet the collision-free requirement during all phases of the mission.

  2. Ship Collision Avoidance by Distributed Tabu Search

    Directory of Open Access Journals (Sweden)

    Dong-Gyun Kim

    2015-03-01

    Full Text Available More than 90% of world trade is transported by sea. The size and speed of ships is rapidly increasing in order to boost economic efficiency. If ships collide, the damage and cost can be astronomical. It is very difficult for officers to ascertain routes that will avoid collisions, especially when multiple ships travel the same waters. There are several ways to prevent ship collisions, such as lookouts, radar, and VHF radio. More advanced methodologies, such as ship domain, fuzzy theory, and genetic algorithm, have been proposed. These methods work well in one-on-one situations, but are more difficult to apply in multiple-ship situations. Therefore, we proposed the Distributed Local Search Algorithm (DLSA to avoid ship collisions as a precedent study. DLSA is a distributed algorithm in which multiple ships communicate with each other within a certain area. DLSA computes collision risk based on the information received from neighboring ships. However, DLSA suffers from Quasi-Local Minimum (QLM, which prevents a ship from changing course even when a collision risk arises. In our study, we developed the Distributed Tabu Search Algorithm (DTSA. DTSA uses a tabu list to escape from QLM that also exploits a modified cost function and enlarged domain of next-intended courses to increase its efficiency. We conducted experiments to compare the performance of DLSA and DTSA. The results showed that DTSA outperformed DLSA.

  3. New pattern theorems for square lattice self-avoiding walks and self-avoiding polygons

    International Nuclear Information System (INIS)

    A general pattern theorem for weighted self-avoiding polygons (SAPs) and self-avoiding walks (SAWs) in Z2 is obtained. The pattern theorem for SAPs fits into the general framework of the pattern theorem for lattice clusters introduced by Madras (1999 Ann. Comb. 3 357-84). Note that, unlike other pattern theorems proved for SAPs, this pattern theorem does not rely on first establishing a relationship between SAPs and SAWs. These results are applied to obtain pattern theorems for self-interacting SAPs and self-interacting SAWs

  4. Avoiding Deontic Explosion by Contextually Restricting Aggregation

    Science.gov (United States)

    Meheus, Joke; Beirlaen, Mathieu; van de Putte, Frederik

    In this paper, we present an adaptive logic for deontic conflicts, called P2.1 r , that is based on Goble's logic SDL a P e - a bimodal extension of Goble's logic P that invalidates aggregation for all prima facie obligations. The logic P2.1 r has several advantages with respect to SDL a P e. For consistent sets of obligations it yields the same results as Standard Deontic Logic and for inconsistent sets of obligations, it validates aggregation "as much as possible". It thus leads to a richer consequence set than SDL a P e. The logic P2.1 r avoids Goble's criticisms against other non-adjunctive systems of deontic logic. Moreover, it can handle all the 'toy examples' from the literature as well as more complex ones.

  5. Mars Rover Local Navigation And Hazard Avoidance

    Science.gov (United States)

    Wilcox, B. H.; Gennery, D. B.; Mishkin, A. H.

    1989-03-01

    A Mars rover sample return mission has been proposed for the late 1990's. Due to the long speed-of-light delays between Earth and Mars, some autonomy on the rover is highly desirable. JPL has been conducting research in two possible modes of rover operation, Computer-Aided Remote Driving and Semiautonomous Navigation. A recently-completed research program used a half-scale testbed vehicle to explore several of the concepts in semiautonomous navigation. A new, full-scale vehicle with all computational and power resources on-board will be used in the coming year to demonstrate relatively fast semiautonomous navigation. The computational and power requirements for Mars rover local navigation and hazard avoidance are discussed.

  6. Avoidable cancers in the Nordic countries. Radiation

    DEFF Research Database (Denmark)

    Winther, J F; Ulbak, Kaare; Dreyer, L;

    1997-01-01

    countries occurs at an average effective dose per capita per year of about 3 mSv (Iceland, 1.1 mSv) from natural sources, and about 1 mSv from man-made sources. While the natural sources are primarily radon in indoor air, natural radionuclides in food, cosmic radiation and gamma radiation from soil and......Exposure to solar and ionizing radiation increases the risk for cancer in humans. Some 5% of solar radiation is within the ultraviolet spectrum and may cause both malignant melanoma and non-melanocytic skin cancer; the latter is regarded as a benign disease and is accordingly not included in our...... estimation of avoidable cancers. Under the assumption that the rate of occurrence of malignant melanoma of the buttocks of both men and women and of the scalp of women would apply to all parts of the body in people completely unexposed to solar radiation, it was estimated that approximately 95% of all...

  7. Avoidable cancers in the Nordic countries. Radiation

    DEFF Research Database (Denmark)

    Winther, J F; Ulbak, Kaare; Dreyer, L; Pukkala, E; Osterlind, A

    1997-01-01

    estimated that the exposure of the Nordic populations to natural sources of ionizing radiation other than radon and to medical sources will each give rise to an annual total of 2120 cancers at various sites. For all types of ionizing radiation, the annual total will be 4420 cancer cases, or 3.9% of all......Exposure to solar and ionizing radiation increases the risk for cancer in humans. Some 5% of solar radiation is within the ultraviolet spectrum and may cause both malignant melanoma and non-melanocytic skin cancer; the latter is regarded as a benign disease and is accordingly not included in our...... estimation of avoidable cancers. Under the assumption that the rate of occurrence of malignant melanoma of the buttocks of both men and women and of the scalp of women would apply to all parts of the body in people completely unexposed to solar radiation, it was estimated that approximately 95% of all...

  8. Weakly directed self-avoiding walks

    CERN Document Server

    Bacher, Axel

    2010-01-01

    We define a new family of self-avoiding walks (SAW) on the square lattice, called weakly directed walks. These walks have a simple characterization in terms of the irreducible bridges that compose them. We determine their generating function. This series has a complex singularity structure and in particular, is not D-finite. The growth constant is approximately 2.54 and is thus larger than that of all natural families of SAW enumerated so far (but smaller than that of general SAW, which is about 2.64). We also prove that the end-to-end distance of weakly directed walks grows linearly. Finally, we study a diagonal variant of this model.

  9. Collision Avoidance of Trains Using Arm7

    Directory of Open Access Journals (Sweden)

    Dr. K. R. R. Mohan Rao

    2015-11-01

    Full Text Available Railways are the popular mode of Transport in almost all major cities of the World. Railways are the most widely used and comfortable modes of transportation system. The major cause for railway accidents is collision of trains on the same track. The main aim of this anti collision system is to identify collision points and to report these error cases to main control room nearer to the station as well as grid control station. Majority of accidents occurred due to improper communication among the network between drivers and control room, due to wrong signaling, worst atmospheric condition, immediate change of route. The train driver doesn’t get proper information in time leading to hazardous situations. So this system by using zigbee protocol provides communication in between trains, which provide information or track id of one train to another train to avoid collision.

  10. Artifacts in CT: recognition and avoidance.

    Science.gov (United States)

    Barrett, Julia F; Keat, Nicholas

    2004-01-01

    Artifacts can seriously degrade the quality of computed tomographic (CT) images, sometimes to the point of making them diagnostically unusable. To optimize image quality, it is necessary to understand why artifacts occur and how they can be prevented or suppressed. CT artifacts originate from a range of sources. Physics-based artifacts result from the physical processes involved in the acquisition of CT data. Patient-based artifacts are caused by such factors as patient movement or the presence of metallic materials in or on the patient. Scanner-based artifacts result from imperfections in scanner function. Helical and multisection technique artifacts are produced by the image reconstruction process. Design features incorporated into modern CT scanners minimize some types of artifacts, and some can be partially corrected by the scanner software. However, in many instances, careful patient positioning and optimum selection of scanning parameters are the most important factors in avoiding CT artifacts. PMID:15537976

  11. Mars rover local navigation and hazard avoidance

    Science.gov (United States)

    Wilcox, B. H.; Gennery, D. B.; Mishkin, A. H.

    1989-01-01

    A Mars rover sample return mission has been proposed for the late 1990's. Due to the long speed-of-light delays between earth and Mars, some autonomy on the rover is highly desirable. JPL has been conducting research in two possible modes of rover operation, Computer-Aided Remote Driving and Semiautonomous Navigation. A recently-completed research program used a half-scale testbed vehicle to explore several of the concepts in semiautonomous navigation. A new, full-scale vehicle with all computational and power resources on-board will be used in the coming year to demonstrate relatively fast semiautonomous navigation. The computational and power requirements for Mars rover local navigation and hazard avoidance are discussed.

  12. Obstacle Avoiding Robot – A Promising One

    Directory of Open Access Journals (Sweden)

    RAKESH CHANDRA KUMAR

    2013-04-01

    Full Text Available In today’s world ROBOTICS is a fast growing and interesting field. ROBOT has sufficient intelligence to cover the maximum area of provided space. It has an infrared sensor which are used to sense the obstacles coming in between the path of ROBOT. It will move in a particular direction and avoid the obstacle which is coming in its path.Autonomous Intelligent Robots are robots that can perform desired tasks in unstructured environments without continuous human guidance. The minimum number of gearmotor allows the walking robot to minimize the power consumption while construct a program that can produce coordination of multi-degree of freedom for the movement of the robot. It is found that two gearmotors are sufficient to produce the basic walking robot and one voltage regulators are needed to control the load where it is capable of supplying enough current to drive two gearmotors for each wheel.

  13. Experiential Avoidance and Technological Addictions in Adolescents.

    Science.gov (United States)

    García-Oliva, Carlos; Piqueras, José A

    2016-06-01

    Background and aims This study focuses on the use of popular information and communication technologies (ICTs) by adolescents: the Internet, mobile phones, and video games. The relationship of ICT use and experiential avoidance (EA), a construct that has emerged as underlying and transdiagnostic to a wide variety of psychological problems, including behavioral addictions, is examined. EA refers to a self-regulatory strategy involving efforts to control or escape from negative stimuli such as thoughts, feelings, or sensations that generate strong distress. This strategy, which may be adaptive in the short term, is problematic if it becomes an inflexible pattern. Thus, the aim of this study was to explore whether EA patterns were associated with addictive or problematic use of ICT in adolescents. Methods A total of 317 students of the Spanish southeast between 12 and 18 years old were recruited to complete a questionnaire that included questions about general use of each ICTs, an experiential avoidance questionnaire, a brief inventory of the Big Five personality traits, and specific questionnaires on problematic use of the Internet, mobile phones, and video games. Results Correlation analysis and linear regression showed that EA largely explained results regarding the addictive use of the Internet, mobile phones, and video games, but not in the same way. As regards gender, boys showed a more problematic use of video games than girls. Concerning personality factors, conscientiousness was related to all addictive behaviors. Discussion and conclusions We conclude that EA is an important construct that should be considered in future models that attempt to explain addictive behaviors. PMID:27363463

  14. Avoidance orientation moderates the effect of threatening messages

    NARCIS (Netherlands)

    Riet, van 't J.P.; Ruiter, R.A.C.; Vries, de H.

    2012-01-01

    This study investigated the influence of individual differences in people's dispositional avoidance orientation on the persuasive effects of low- and high-threat messages promoting moderate drinking. First, participents (N = 99) individual differences in avoidance orientation were assessed, after wh

  15. US Forest Service Aerial Fire Retardant Hydrographic Avoidance Areas: Aquatic

    Data.gov (United States)

    US Forest Service, Department of Agriculture — A map services on the www depicting aerial retardant avoidance areas for hydrographic feature data. Aerial retardant avoidance area for hydrographic feature data...

  16. [What type of avoidance for peanut allergic children?].

    Science.gov (United States)

    Feuillet-Dassonval, C; Agne, P-S-A; Rancé, F; Bidat, E

    2006-09-01

    We analyzed, from the literature, the balance benefit/risk of a strict avoidance of peanut in children with peanut allergy. The benefits of a strict avoidance diet seem limited: reactions to the low doses and to the peanut oil refined are rare and most often slight. It is not proven that a strict avoidance facilitates the cure of allergy. On the other hand, strict avoidance could induce a worsening of allergy, with deterioration of quality of life, creation of food neophobia. In case of cure of allergy, it is difficult to normalize the diet after a strict avoidance. Outside of the rare sensitive patients to a very low dose of peanut, for which a strict avoidance is counseled, the report benefits risk is in favor of the prescription of adapted avoidance to the eliciting dose. For the majority of the peanut allergic children, it seems to us that the avoidance can and must be limited to the non hidden peanut. PMID:16828543

  17. Unobserved Tax Avoidance and the Tax Elasticity of FDI

    OpenAIRE

    Egger, Peter; Merlo, Valeria; Wamser, Georg

    2014-01-01

    This paper investigates the tax responsiveness of multinational firms’ investment decisions in foreign countries, distinguishing firms that are able to avoid taxes (avoiders) from those that are not (non-avoiders). From a theoretical point of view, the tax responsiveness of firms crucially depends on this distinction. Empirically, however, a firm’s ability to avoid profit taxes is inherently unobservable to the researcher. To address this problem, we use a finite mixture modeling approach whi...

  18. Effects of optimism on creativity under approach and avoidance motivation

    OpenAIRE

    Icekson, Tamar; Roskes, Marieke; Moran, Simone

    2014-01-01

    Focusing on avoiding failure or negative outcomes (avoidance motivation) can undermine creativity, due to cognitive (e.g., threat appraisals), affective (e.g., anxiety), and volitional processes (e.g., low intrinsic motivation). This can be problematic for people who are avoidance motivated by nature and in situations in which threats or potential losses are salient. Here, we review the relation between avoidance motivation and creativity, and the processes underlying this relation. We highli...

  19. Relative valuation of alternative methods of tax avoidance

    OpenAIRE

    Inger, Kerry Katharine

    2012-01-01

    This paper examines the relative valuation of alternative methods of tax avoidance. Prior studies find that firm value is positively associated with overall measures of tax avoidance; I extend this research by providing evidence that investors distinguish between methods of tax reduction in their valuation of tax avoidance. The impact of tax avoidance on firm value is a function of tax risk, permanence of tax savings, tax planning costs, implicit taxes and contrasts in disclosures of tax re...

  20. Avoidance Learning: A Review of Theoretical Models and Recent Developments

    Directory of Open Access Journals (Sweden)

    Angelos-Miltiadis Krypotos

    2015-07-01

    contemporary theories of avoidance learning. Based on the theories, experimental findings and clinical observations reviewed, we distil key principles of how adaptive and maladaptive avoidance behavior is acquired and maintained. We highlight clinical implications of avoidance learning theories and describe intervention strategies that could reduce maladaptive avoidance and prevent its return. We end with a brief overview of recent developments and avenues for further research.

  1. Conjunctions and Collision Avoidance with Electrodynamic Tethers

    Science.gov (United States)

    Levin, E.

    2013-09-01

    Electrodynamic propulsion technology is currently in development by NASA, ESA, and JAXA for the purpose of affordable removal of large debris objects from LEO. At the same time, the Naval Research Laboratory is preparing a 3U CubeSat with a 1-km electrodynamic tether for a flight demonstration of electrodynamic propulsion. This type of propulsion does not require fuel. The electrodynamic thrust is the Lorentz force acting on the electric current in a long conductor (tether) in the geomagnetic field. Electrons are collected from the ambient plasma on one end and emitted back into the plasma from the other end. The electric current loop is closed through the ionosphere, as demonstrated in two previous flights. The vehicle is solar powered. To support safe navigation of electrodynamic tethers, proper conjunction analysis and collision avoidance strategies are needed. The typical lengths of electrodynamic tethers for near-term applications are measured in kilometers, and the conjunction geometry is very different from the geometry of conjunctions between compact objects. It is commonly thought that the collision cross-section in a conjunction between a tether and a compact object is represented by the product of the tether length and the size of the object. However, rigorous analysis shows that this is not the case, and that the above assumption leads to grossly overestimated collision probabilities. The paper will present the results of a detailed mathematical analysis of the conjunction geometry and collision probabilities in close approaches between electrodynamic tethers and compact objects, such as satellites, rocket bodies, and debris fragments. Electrodynamic spacecraft will not require fuel, and therefore, can thrust constantly. Their orbit transfers can take many days, but can result in major orbit changes, including large rotations of the orbital plane, both in the inclination and the node. During these orbit transfers, the electrodynamic spacecraft will

  2. 47 CFR 51.609 - Determination of avoided retail costs.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Determination of avoided retail costs. 51.609... (CONTINUED) INTERCONNECTION Resale § 51.609 Determination of avoided retail costs. (a) Except as provided in § 51.611, the amount of avoided retail costs shall be determined on the basis of a cost study...

  3. Deforestation, leakage and avoided deforestation policies: a spatial analysis

    OpenAIRE

    DELACOTE, Philippe; Elizabeth J. Z. Robinson; Roussel, Sebastien

    2015-01-01

    This paper analyses the impact of several avoided deforestation policies within a patchy forested landscape. Central is the idea that deforestation choices in one area influence deforestation decisions in nearby patches. We explore the interplay between forest landscapes comprising heterogeneous patches, localised spatial displacement, and avoided deforestation policies. Avoided deforestation policies at a landscape level are respectively: two Payments for Environmental Services (PES) policie...

  4. A missed scalp laceration causing avoidable sequelae

    Science.gov (United States)

    Basyuni, Shadi; Panayi, Andreana; Sharma, Valmiki; Santhanam, Vijay

    2016-01-01

    Introduction We present the case of an overlooked scalp laceration in an 81-year-old lady who presented with polytrauma following a fall down stairs. Complications that developed required more extensive treatment compared to what would have sufficed with early identification. Presentation of case Imaging on admission to hospital showed multiple vertebrae and rib fractures as well as a large cranial subcutaneous haematoma with no intracerebral bleed. Before the laceration was identified, the patient developed acute anaemia requiring transfusion. Continued reduction in haemoglobin levels called for a more thorough examination of the scalp. Investigation, following copious irrigation, revealed a large laceration. The presence of infection and necrotic tissue necessitated a general anaesthetic for debridement and closure. Disscussion Diagnostic errors are more common in patients presenting with multiple or severe injuries. Initial management in trauma cases should focus on more evident or life threatening injuries However, it is important that reflections and recommendations are continually made to reduce diagnostic errors, which are higher in polytraumatised patients. Various factors including haemodynamic instability and patient positioning added to the elusive nature of this wound. Adequate examination of lacerations requires thorough cleaning as coagulated blood and other material may obscure findings. This is particularly important in scalp lacerations where the overlying hair can form a barrier that is effective at hiding the wound edges. Conclusion This case highlights the importance of a thorough secondary survey; an effective examination technique would have avoided the need for extensive treatment to manage the sequelae of the missed scalp laceration. PMID:27088847

  5. Avoidable cancers in the Nordic countries. Occupation

    DEFF Research Database (Denmark)

    Dreyer, L; Andersen, A; Pukkala, E

    1997-01-01

    around the year 2000, with 1,890 among men and fewer than 25 among women. The proportions that could be avoided if industrial carcinogens were eliminated would be 70% of mesotheliomas, 20% of cancers of the nasal cavity and sinuses, 12% of lung cancers, 5% of laryngeal cancers, 2% of urinary bladder...... million people (3.7 million men and 0.2 million women) in the Nordic countries were potentially exposed to above-average levels of one or more verified industrial carcinogens. It is expected that these exposures will result in a total of about 1,900 new cases of cancer every year in the Nordic countries...... cancers, 1% of the leukaemias, and 1% of renal cancers. Overall, it is estimated that verified industrial carcinogens will account for approximately 3% of all cancers in men and less than 0.1% of all cancers in women in the Nordic countries around the year 2000. No attempt was made to estimate the...

  6. Avoiding selection bias in gravitational wave astronomy

    International Nuclear Information System (INIS)

    When searching for gravitational waves in the data from ground-based gravitational wave detectors, it is common to use a detection threshold to reduce the number of background events which are unlikely to be the signals of interest. However, imposing such a threshold will also discard some real signals with low amplitude, which can potentially bias any inferences drawn from the population of detected signals. We show how this selection bias is naturally avoided by using the full information from the search, considering both the selected data and our ignorance of the data that are thrown away, and considering all relevant signal and noise models. This approach produces unbiased estimates of parameters even in the presence of false alarms and incomplete data. This can be seen as an extension of previous methods into the high false rate regime where we are able to show that the quality of parameter inference can be optimized by lowering thresholds and increasing the false alarm rate. (paper)

  7. Approach-avoidance activation without anterior asymmetry

    Directory of Open Access Journals (Sweden)

    AnderoUusberg

    2014-03-01

    Full Text Available Occasionally, the expected effects of approach-avoidance motivation on anterior EEG alpha asymmetry fail to emerge, particularly in studies using affective picture stimuli. These null findings have been explained by insufficient motivational intensity of, and/or overshadowing interindividual variability within the responses to emotional pictures. These explanations were systematically tested using data from 70 students watching 5 types of affective pictures ranging from very pleasant to unpleasant. The stimulus categories reliably modulated self-reports as well as the amplitude of late positive potential, an ERP component reflecting orienting towards motivationally significant stimuli. The stimuli did not, however, induce expected asymmetry effects either for the sample or individual participants. Even while systematic stimulus-dependent individual differences emerged in self-reports as well as LPP amplitudes, the asymmetry variability was dominated by stimulus-independent interindividual variability. Taken together with previous findings, these results suggest that under some circumstances anterior asymmetry may not be an inevitable consequence of core affect. Instead, state asymmetry shifts may be overpowered by stable trait asymmetry differences and/or stimulus-independent yet situation-dependent interindividual variability, possibly caused by processes such as emotion regulation or anxious apprehension.

  8. Self-avoiding walks crossing a square

    International Nuclear Information System (INIS)

    We study a restricted class of self-avoiding walks (SAWs) which start at the origin (0, 0), end at (L, L), and are entirely contained in the square [0, L] x [0, L] on the square lattice Z2. The number of distinct walks is known to grow as λL2+o(L2). We estimate λ = 1.744 550 ± 0.000 005 as well as obtaining strict upper and lower bounds, 1.628 1/3). We also consider the model in which a weight or fugacity x is associated with each step of the walk. This gives rise to a canonical model of a phase transition. For x 1/μ it grows as L2. Here μ is the growth constant of unconstrained SAWs in Z2. For x = 1/μ we provide numerical evidence, but no proof, that the average walk length grows as L4/3. Another problem we study is that of SAWs, as described above, that pass through the central vertex of the square. We estimate the proportion of such walks as a fraction of the total, and find it to be just below 80% of the total number of SAWs. We also consider Hamiltonian walks under the same restriction. They are known to grow as τL2+o(L2) on the same L x L lattice. We give precise estimates for τ as well as upper and lower bounds, and prove that τ < λ

  9. The amygdala: securing pleasure and avoiding pain

    Directory of Open Access Journals (Sweden)

    Anushka B P Fernando

    2013-12-01

    Full Text Available The amygdala has traditionally been associated with fear, mediating the impact of negative emotions on memory. However, this view does not fully encapsulate the function of the amygdala, nor the impact that processing in this structure has on the motivational limbic corticostriatal circuitry of which it is an important structure. Here we discuss the interactions between different amygdala nuclei with cortical and striatal regions involved in motivation; interconnections and parallel circuitries that have become increasingly understood in recent years. We review the evidence that the amygdala stores memories that allow initially motivationally neutral stimuli to become associated through pavlovian conditioning with motivationally relevant outcomes which, importantly, can be either appetitive (e.g. food or aversive (e.g. electric shock. We also consider how different psychological processes supported by the amygdala such as conditioned reinforcement and punishment, conditioned motivation and suppression, and conditioned approach and avoidance behavior, are not only psychologically but also neurobiologically dissociable, being mediated by distinct yet overlapping neural circuits within the limbic corticostriatal circuitry. Clearly the role of the amygdala goes beyond encoding aversive stimuli to also encode the appetitive, requiring an appreciation of the amygdala’s mediation of both appetitive and fearful behavior through diverse psychological processes.

  10. Avoided valence transition in a plutonium superconductor.

    Science.gov (United States)

    Ramshaw, B J; Shekhter, Arkady; McDonald, Ross D; Betts, Jon B; Mitchell, J N; Tobash, P H; Mielke, C H; Bauer, E D; Migliori, Albert

    2015-03-17

    The d and f electrons in correlated metals are often neither fully localized around their host nuclei nor fully itinerant. This localized/itinerant duality underlies the correlated electronic states of the high-Tc cuprate superconductors and the heavy-fermion intermetallics and is nowhere more apparent than in the 5f valence electrons of plutonium. Here, we report the full set of symmetry-resolved elastic moduli of PuCoGa5--the highest Tc superconductor of the heavy fermions (Tc = 18.5 K)--and find that the bulk modulus softens anomalously over a wide range in temperature above Tc. The elastic symmetry channel in which this softening occurs is characteristic of a valence instability--therefore, we identify the elastic softening with fluctuations of the plutonium 5f mixed-valence state. These valence fluctuations disappear when the superconducting gap opens at Tc, suggesting that electrons near the Fermi surface play an essential role in the mixed-valence physics of this system and that PuCoGa5 avoids a valence transition by entering the superconducting state. The lack of magnetism in PuCoGa5 has made it difficult to reconcile with most other heavy-fermion superconductors, where superconductivity is generally believed to be mediated by magnetic fluctuations. Our observations suggest that valence fluctuations play a critical role in the unusually high Tc of PuCoGa5. PMID:25737548

  11. Avoiding sexual harassment liability in veterinary practices.

    Science.gov (United States)

    Lacroix, C A; Wilson, J F

    1996-05-15

    Harassment based on gender violates the rule of workplace equality established by Title VII of the Civil Rights Act and enforced by the EEOC. In 1986, the US Supreme Court, in Meritor Savings Bank v Vinson, established the criteria that must be met for a claim of hostile environment sexual harassment to be considered valid. Plaintiffs must show that they were subjected to conduct based on their gender, that it was unwelcome, and that it was severe and pervasive enough to alter their condition of employment, resulting in an abusive working environment. There have been few sexual harassment cases involving veterinary professionals, and it is our goal to help keep the number of filed actions to a minimum. The most effective way to avoid hostile environment sexual harassment claims is to confront the issue openly and to adopt a sexual harassment policy for the practice. When it comes to sexual harassment, an ounce of prevention is unquestionably worth a pound of cure. PMID:8641947

  12. Why Do Consumers Avoid Certain Brands? : A Study of Brand Avoidance Within the Swedish Cosmetics Industry

    OpenAIRE

    Vong, Amy; Hellberg, Anna; Melander, Joanna

    2016-01-01

    Background - As of today, the positive forms of consumer-brand relationships have been intensively researched, whereas its counterpart has attained far less attention. Whilst current literature is focused on increasing positive brand equity, the knowledge of negative brand equity is sparse. When the brand-consumer relationship is negatively affected and the brand equity is unfavourable, rejection of a specific brand, namely brand avoidance might occur. This may affect companies negatively if ...

  13. How biological microtubules may avoid decoherence

    International Nuclear Information System (INIS)

    Full text: Entangled superpositions persisting for hundreds of milliseconds in protein assemblies such as microtubules (MTs) are proposed in biological functions, e.g. quantum computation relevant to consciousness in the Penrose-Hameroff 'Orch OR' model. Cylindrical polymers of the protein tubulin, MTs organize cell activities. The obvious question is how biological quantum states could avoid decoherence, e.g. in the brain at 37.6 degrees centigrade. Screening/sheelding: tubulin protein states/functions are governed by van der Waals London forces, quantum interactions among clouds of delocalizable electrons in nonpolar 'hydrophobic' intra-protein pockets screened from external van der Waals thermal interactions. Such pockets include amino acid resonance structures benzene and indole rings. (Anesthetic gases erase consciousness solely by interfering with London forces in hydrophobic pockets in various brain proteins). Hence tubulin states may act as superpositioned qubits also shielded at the MT level by counter-ion Debye plasma layers (due to charged C-termini tails on tubulin) and by water-ordering actin gels which embed MTs in a quasi-solid. Biological systems may also exploit thermodynamic gradients to give extremely low effective temperatures. Decoherence free subspaces: paradoxically, a system coupled strongly to its environment through certain degrees of freedom can effectively 'freeze' other degrees of freedom (quantum Zeno effect), enabling coherent superpositions and entanglement to persist. Metabolic energy supplied to MT collective dynamics (e.g. Froehlich coherence) can cause Bose-Einstein condenzation and counter decoherence as lasers avoid decoherence at room temperature. Topological quantum error correction: MT lattice structure reveals various helical winding paths through adjacent tubulins which follow the Fibonacci series. Propagation/interactions of quasi-particles along these paths may process information. As proposed by Kitaev (1997), various

  14. EDITORIAL AVOIDABLE MORTALITY OF SCIENTIFIC MANUSCRIPTS

    Directory of Open Access Journals (Sweden)

    Mauricio Palacios

    2010-06-01

    Full Text Available Colombia Médica publishes 64% of the original research articles submitted to editorial process, which highlights the rigor of the editorial review system; while at the same time, generating a reflection on the causes for rejecting material submitted for publication as an input for the Journal’s collaborators.The review of the file of articles rejected by the Journal leads us to arbitrarily discriminating the causes for rejecting scientific documents into two groups: A first group we will call «lost causes», which centers on the lack of ethical evaluation, research design flaws, and plagiarism. And the second group, «manuscripts with avoidable rejection», which includes deficiencies in following the editorial guidelines for authors, inadequate writing, and delays by authors in submitting answers to observations raised during an initial evaluation. Documents classifying in the latter group could have had an opportunity with a bit of joint effort between the authors and the editorial board; and in all cases, by correcting errors and seeking support from, among others, expert consultants, these could, potentially, be revived by submitting them to a journal with a lower impact than that in which they were rejected.Among the reasons for the lost causes, we find that faults in the structure of institutional research take up considerable space. Institutions considering scientific production as one of their assets, must invest on the conformation and growth of an ethics committee on research that reasonably provides researchers with social, environmental, and ethical reflection elements to enrich research proposals. With bioethics foundations, Colombian and international norms do not consider other forms of ethical evaluation of the projects, and; consequently, neither does the Editorial Committee. Furthermore, anyone seeking to conduct clinical trials must register the entity in any of the international data bases that permit inputting the

  15. EDITORIAL AVOIDABLE MORTALITY OF SCIENTIFIC MANUSCRIPTS

    Directory of Open Access Journals (Sweden)

    Mauricio Palacios

    2010-06-01

    Full Text Available Colombia Médica publishes 64% of the original research articles submitted to editorial process, which highlights the rigor of the editorial review system; while at the same time, generating a reflection on the causes for rejecting material submitted for publication as an input for the Journal’s collaborators. The review of the file of articles rejected by the Journal leads us to arbitrarily discriminating the causes for rejecting scientific documents into two groups: A first group we will call «lost causes», which centers on the lack of ethical evaluation, research design flaws, and plagiarism. And the second group, «manuscripts with avoidable rejection», which includes deficiencies in following the editorial guidelines for authors, inadequate writing, and delays by authors in submitting answers to observations raised during an initial evaluation. Documents classifying in the latter group could have had an opportunity with a bit of joint effort between the authors and the editorial board; and in all cases, by correcting errors and seeking support from, among others, expert consultants, these could, potentially, be revived by submitting them to a journal with a lower impact than that in which they were rejected. Among the reasons for the lost causes, we find that faults in the structure of institutional research take up considerable space. Institutions considering scientific production as one of their assets, must invest on the conformation and growth of an ethics committee on research that reasonably provides researchers with social, environmental, and ethical reflection elements to enrich research proposals. With bioethics foundations, Colombian and international norms do not consider other forms of ethical evaluation of the projects, and; consequently, neither does the Editorial Committee. Furthermore, anyone seeking to conduct clinical trials must register the entity in any of the international data bases that permit inputting the

  16. AVOID BECOMING A VICTIM OF COUNTERFEIT ITEMS

    Energy Technology Data Exchange (ETDEWEB)

    WARRINER RD

    2011-07-13

    In today's globalized economy, we cannot live without imported products. Most people do not realize how thin the safety net of regulation and inspection really is. Less than three percent of imported products receive any form of government inspection prior to sale. Avoid flea markets, street vendors and deep discount stores. The sellers of counterfeit wares know where to market their products. They look for individuals who are hungry for a brand name item but do not want to pay a brand name price for it. The internet provides anonymity to the sellers of counterfeit products. Unlike Europe, U.S. law does not hold internet-marketing organizations, responsible for the quality of the products sold on their websites. These organizations will remove an individual vendor when a sufficient number of complaints are lodged, but they will not take responsibility for the counterfeit products you may have purchased. EBay has a number of counterfeit product guides to help you avoid being a victim of the sellers of these products. Ten percent of all medications taken worldwide are counterfeit. If you do buy medications on-line, be sure that the National Association of Boards of Pharmacy Verified Internet Pharmacy Practice Sites (VIPPS) recommends the pharmacy you choose to use. Inspect all medication purchases and report any change in color, shape, imprinting or odor to your pharmacist. If you take generic medications these attributes may change from one manufacturer to another. Your pharmacist should inform you of any changes when you refill your prescription. If they do not, get clarification prior to taking the medication. Please note that the Federal Drug Administration (FDA) does not regulate supplements. The FDA only steps in when a specific supplement proves to cause physical harm or contains a regulated ingredient. Due to counterfeiting, Underwriters Laboratories (UL) changed their label design three times since 1996. The new gold label should be attached to the cord

  17. [PARTICIPANT OBSERVATION TO AVOID SUBJUGATING "OTHER" ETHICS].

    Science.gov (United States)

    Brelet, Claudine

    2015-10-01

    When we want to implant efficient, lasting healthcare programmes in order to improve the health conditions of a population, we have to be able to distance ourselves from our own conceptions of what is ethical or not, good or bad, better or worse. In fact, these notions can be conceived differently according to the sociocultural context. Thus, international aid has taught us how harmful it can be to impose changes which, a priori, may go against "other" ethics. The imbalances and misunderstandings that result always jeopardise the success of programmes which, otherwise, might have been accepted and even taken over by the populations concerned. Therefore the theoretical and methodological approaches of anthropology can contribute significantly to having certain programmes proposed which respect both so-called 'universal' values and the values of local populations who could benefit from them. In this article, by examining the history of the theoretical and methodological developments of participant observation, we will see how it could constitute an initiatory praxis to ethics in general and culturally enrich certain principles advocated by biomedical ethics. By enabling semantic bridges from one culture to another, and vice versa, this classic approach of anthropology makes it possible to integrate into the ways of implanting healthcare projects the manner in which a population perceives its own systems of reference and values. From the scientific point of view, it is essential to develop approaches which avoid having "other". ethics subjugated to Western concepts. Research on ethnomedicines could therefore contribute to their being taken into account in projects aiming at the common good. PMID:26911080

  18. Towards better patient care: drugs to avoid.

    Science.gov (United States)

    2013-04-01

    Common sense dictates that one should choose tried and tested drugs with proven, concrete benefits that outweigh their adverse effects. Many new drugs are approved each year, often despite a lack of solid evidence that they are any better than existing treatments. Worse, some are approved despite being less effective or more harmful than current options. Massive promotion is used to ensure that such drugs achieve a positive image in the eyes of healthcare professionals and patients. Renowned "opinion leaders" intervene in their favour at conferences and in specialist media, and their opinions are further propagated by specialists in the field. Finally, campaigns in the lay media are used to highlight the target illness, encouraging patients to request a prescription. New data sometimes show that older, initially promising drugs are less effective or more harmful than first thought. For all these reasons, many drugs that are now present on the market are more harmful than beneficial and should be avoided. Unfortunately, negative assessment data and warnings are often drowned in the flood of promotion and advertising. Front-line healthcare professionals who are determined to act in their patients' best interests can find themselves swimming against a tide of specialist opinion, marketing authorisation, and reimbursement decisions. By leaving drugs that are more harmful than beneficial on the market and contenting themselves with simple half-measures, healthcare authorities are failing in their duty to protect patients. Prescrire, a journal funded solely by its subscribers, does not seek to do the work of health authorities, and does not have the means to do so. Prescrire's goal is simply to help healthcare professionals provide better care. The following text lists the principal drugs that we consider more harmful than beneficial, based on our reviews published between 2010 and 2012 in our French edition. These drugs should not be used. Patients and healthcare

  19. A chance to avoid mistakes human error

    International Nuclear Information System (INIS)

    Trying to give an answer to the lack of public information in the industry, in relationship with the different tools that are managed in the nuclear industry for minimizing the human error, a group of workers from different sections of the St. Maria de Garona NPP (Quality Assurance/ Organization and Human Factors) decided to embark on a challenging and exciting project: 'Write a book collecting all the knowledge accumulated during their daily activities, very often during lecture time of external information received from different organizations within the nuclear industry (INPO, WANO...), but also visiting different NPP's, maintaining meetings and participating in training courses related de Human and Organizational Factors'. Main objective of the book is presenting to the industry in general, the different tools that are used and fostered in the nuclear industry, in a practical way. In this way, the assimilation and implementation in others industries could be possible and achievable in and efficient context. One year of work, and our project is a reality. We have presented and abstract during the last Spanish Nuclear Society meeting in Sevilla, last October...and the best, the book is into the market for everybody in web-site: www.bubok.com. The book is structured in the following areas: 'Errare humanum est': Trying to present what is the human error to the reader, its origin and the different barriers. The message is that the reader see the error like something continuously present in our lives... even more frequently than we think. Studying its origin can be established aimed at barriers to avoid or at least minimize it. 'Error's bitter face': Shows the possible consequences of human errors. What better that presenting real experiences that have occurred in the industry. In the book, accidents in the nuclear industry, like Tree Mile Island NPP, Chernobyl NPP, and incidents like Davis Besse NPP in the past, helps to the reader to make a reflection about the

  20. Adolescents' approach-avoidance behaviour in the context of pain.

    Science.gov (United States)

    Fisher, Emma; Keogh, Edmund; Eccleston, Christopher

    2016-02-01

    Adolescents who experience pain often face competing goals and have to choose whether to approach (confront) or avoid pain. This study investigates the decisions adolescents make when their pain conflicts with a valued goal. Adolescents between the ages of 15 and 18 years (N = 170) completed questionnaires on general and pain-specific anxiety, courage, and dispositional avoidance. Adolescents were presented with 16 vignettes (8 high pain intensity, 8 low pain intensity), which described pain conflicting with a goal (eg, doing well at school, seeing friends). Adolescents rated goals for importance and reported how likely they would be to approach or avoid each pain. Adolescents were more likely to avoid and were more fearful of high pain intensity than low pain intensity vignettes. Pain anxiety predicted higher levels of avoidance for both pain intensities. General anxiety was not a significant predictor of avoidance for either pain intensity. Goal importance promoted approach of goals, but only when pain was described as intense. However, pain anxiety predicted avoidance beyond the importance of goals for high pain intensity vignettes. In addition, we compared approach-avoidance of adolescents with and without chronic pain; analyses revealed no differences in approach-avoidance behaviour. We also found that behavioural endurance was predictive of approach and dispositional avoidance predicted higher avoidance, but courage was not predictive of behaviour in this task. We adopt a motivational perspective when interpreting the findings and consider whether the fear-avoidance model should be extended to include the function of avoidance or approach in the pursuit of a desired goal. PMID:26458091

  1. Self-avoiding walk enumeration via the lace expansion

    International Nuclear Information System (INIS)

    We introduce a new method for the enumeration of self-avoiding walks based on the lace expansion. We also introduce an algorithmic improvement, called the two-step method, for self-avoiding walk enumeration problems. We obtain significant extensions of existing series on the cubic and hypercubic lattices in all dimensions d ≥ 3: we enumerate 32-step self-avoiding polygons in d = 3, 26-step self-avoiding polygons in d = 4, 30-step self-avoiding walks in d = 3, and 24-step self-avoiding walks and polygons in all dimensions d ≥ 4. We analyze these series to obtain estimates for the connective constant and various critical exponents and amplitudes in dimensions 3 ≤ d ≤ 8. We also provide major extensions of 1/d expansions for the connective constant and for two critical amplitudes

  2. Individual differences in physiological flexibility predict spontaneous avoidance.

    Science.gov (United States)

    Aldao, Amelia; Dixon-Gordon, Katherine L; De Los Reyes, Andres

    2016-08-01

    People often regulate their emotions by resorting to avoidance, a putatively maladaptive strategy. Prior work suggests that increased psychopathology symptoms predict greater spontaneous utilisation of this strategy. Extending this work, we examined whether heightened resting cardiac vagal tone (which reflects a general ability to regulate emotions in line with contextual demands) predicts decreased spontaneous avoidance. In Study 1, greater resting vagal tone was associated with reduced spontaneous avoidance in response to disgust-eliciting pictures, beyond anxiety and depression symptoms and emotional reactivity. In Study 2, resting vagal tone interacted with anxiety and depression symptoms to predict spontaneous avoidance in response to disgust-eliciting film clips. The positive association between symptoms and spontaneous avoidance was more pronounced among participants with reduced resting vagal tone. Thus, increased resting vagal tone might protect against the use of avoidance. Our findings highlight the importance of assessing both subjective and biological processes when studying individual differences in emotion regulation. PMID:26147365

  3. Avoidance-related EEG asymmetry predicts circulating interleukin-6.

    Science.gov (United States)

    Shields, Grant S; Moons, Wesley G

    2016-03-01

    Recent research has linked avoidance-oriented motivational states to elevated pro-inflammatory cytokine levels. According to one of many theories regarding the association between avoidance and cytokine levels, because the evolutionarily basic avoidance system may be activated when an organism is threatened or overwhelmed, an associated inflammatory response may be adaptive for dealing with potential injury in such threatening situations. To examine this hypothesis, we tested whether the neural correlate of avoidance motivation associates with baseline levels of the circulating pro-inflammatory cytokine interleukin-6 (IL-6). Controlling for covariates, greater resting neural activity in the right frontal cortex relative to the left frontal cortex-the neural correlate of avoidance motivation-was associated with baseline IL-6. These results thus support the hypothesis that the avoidance motivational system may be closely linked to systemic inflammatory activity. PMID:26461246

  4. Generalisation of fear and avoidance along a semantic continuum.

    Science.gov (United States)

    Boyle, Sean; Roche, Bryan; Dymond, Simon; Hermans, Dirk

    2016-01-01

    Directly conditioned fear and avoidance readily generalises to dissimilar but conceptually related stimuli. Here, for the first time, we examined the conceptual/semantic generalisation of both fear and avoidance using real words (synonyms). Participants were first exposed to a differential fear conditioning procedure in which one word (e.g., "broth"; CS+) was followed with brief electric shock [unconditioned stimulus (US)] and another was not (e.g., "assist"; CS-). Next, an instrumental conditioning phase taught avoidance in the presence the CS+ but not the CS-. During generalisation testing, synonyms of the CS+ (e.g., "soup"; GCS+) and CS- (e.g., "help"; GCS-) were presented in the absence of shock. Conditioned fear and avoidance, measured via skin conductance responses, behavioural avoidance and US expectancy ratings, generalised to the semantically related, but not to the semantically unrelated, synonyms. Findings have implications for how natural language categories and concepts mediate the expansion of fear and avoidance repertoires in clinical contexts. PMID:25648156

  5. Avoidance and tolerance to avian herbivores in aquatic plants

    OpenAIRE

    Hidding, A.

    2009-01-01

    Tolerance and avoidance are the two contrasting strategies that plants may adopt to cope with herbivores. Tolerance traits define the degree to which communities remain unaffected by herbivory. Trade-offs between herbivore avoidance and competitive strength and between avoidance and colonization ability may shape population traits and communities under herbivory. In this thesis I present comparative and experimental studies on populations and communities of aquatic plants and how they deal wi...

  6. Universality of collapsing two-dimensional self-avoiding trails

    International Nuclear Information System (INIS)

    Results of a numerically exact transfer matrix calculation for the model of interacting self-avoiding trails are presented. The results lead to the conclusion that at the collapse transition, self-avoiding trails are in the same universality class as the O(n = 0) model of Bloete and Nienhuis (or vertex-interacting self-avoiding walk), which has thermal exponent ν = 12/23, contrary to previous conjectures. (fast track communication)

  7. Quantum walks with tuneable self-avoidance in one dimension

    OpenAIRE

    Elizabeth Camilleri; Rohde, Peter P.; Jason Twamley

    2014-01-01

    Quantum walks exhibit many unique characteristics compared to classical random walks. In the classical setting, self-avoiding random walks have been studied as a variation on the usual classical random walk. Here the walker has memory of its previous locations and preferentially avoids stepping back to locations where it has previously resided. Classical self-avoiding random walks have found numerous algorithmic applications, most notably in the modelling of protein folding. We consider the a...

  8. Multiobjective Optimization Based Vessel Collision Avoidance Strategy Optimization

    OpenAIRE

    Qingyang Xu; Chuang Zhang; Ning Wang

    2014-01-01

    The vessel collision accidents cause a great loss of lives and property. In order to reduce the human fault and greatly improve the safety of marine traffic, collision avoidance strategy optimization is proposed to achieve this. In the paper, a multiobjective optimization algorithm NSGA-II is adopted to search for the optimal collision avoidance strategy considering the safety as well as economy elements of collision avoidance. Ship domain and Arena are used to evaluate the collision risk in ...

  9. The mnemonic mover: nostalgia regulates avoidance and approach motivation

    OpenAIRE

    Stephan, Elena; Wildschut, Tim; Sedikides, Constantine; Zhou, X.; He, W.; Routledge, Clay; Cheung, Wing-Yee; Vingerhoets, A.

    2014-01-01

    In light of its role in maintaining psychological equanimity, we proposed that nostalgia—a self-relevant, social, and predominantly positive emotion—regulates avoidance and approach motivation. We advanced a model in which (a) avoidance motivation triggers nostalgia and (b) nostalgia, in turn, increases approach motivation. As a result, nostalgia counteracts the negative impact of avoidance motivation on approach motivation. Five methodologically diverse studies supported this regulatory mode...

  10. Exponents of intrachain correlation for self-avoiding walks and knotted self-avoiding polygons

    Science.gov (United States)

    Uehara, Erica; Deguchi, Tetsuo

    2013-08-01

    We show numerically that critical exponents for two-point intrachain correlation of an infinite chain characterize those of finite chains in self-avoiding walk (SAW) and self-avoiding polygon (SAP) under a topological constraint. We evaluate short-distance exponents θ(i, j) through the probability distribution functions of the distance between the ith and jth vertices of N-step SAW (or SAP with a knot) for all pairs (1 ⩽ i, j ⩽ N). We construct the contour plot of θ(i, j), and express it as a function of i and j. We suggest that it has quite a simple structure. Here exponents θ(i, j) generalize des Cloizeaux’s three critical exponents for short-distance intrachain correlation of SAW, and we show the crossover among them. We also evaluate the diffusion coefficient of knotted SAP for a few knot types, which can be calculated with the probability distribution functions of the distance between two nodes.

  11. Exponents of intrachain correlation for self-avoiding walks and knotted self-avoiding polygons

    International Nuclear Information System (INIS)

    We show numerically that critical exponents for two-point intrachain correlation of an infinite chain characterize those of finite chains in self-avoiding walk (SAW) and self-avoiding polygon (SAP) under a topological constraint. We evaluate short-distance exponents θ(i, j) through the probability distribution functions of the distance between the ith and jth vertices of N-step SAW (or SAP with a knot) for all pairs (1 ⩽ i, j ⩽ N). We construct the contour plot of θ(i, j), and express it as a function of i and j. We suggest that it has quite a simple structure. Here exponents θ(i, j) generalize des Cloizeaux’s three critical exponents for short-distance intrachain correlation of SAW, and we show the crossover among them. We also evaluate the diffusion coefficient of knotted SAP for a few knot types, which can be calculated with the probability distribution functions of the distance between two nodes. (paper)

  12. 31 CFR 800.104 - Transactions or devices for avoidance.

    Science.gov (United States)

    2010-07-01

    ... controlled by a foreign national. With a view towards avoiding possible application of section 721... (Continued) OFFICE OF INVESTMENT SECURITY, DEPARTMENT OF THE TREASURY REGULATIONS PERTAINING TO...

  13. Approach, avoidance, and affect: a meta-analysis of approach-avoidance tendencies in manual reaction time tasks

    OpenAIRE

    Phaf, R. Hans; Mohr, Sören E.; Rotteveel, Mark; Jelte M Wicherts

    2014-01-01

    Approach action tendencies toward positive stimuli and avoidance tendencies from negative stimuli are widely seen to foster survival. Many studies have shown that approach and avoidance arm movements are facilitated by positive and negative affect, respectively. There is considerable debate whether positively and negatively valenced stimuli prime approach and avoidance movements directly (i.e., immediate, unintentional, implicit, automatic, and stimulus-based), or indirectly (i.e., after cons...

  14. Approach, avoidance, and affect: A meta-analysis of approach-avoidance tendencies in manual reaction time tasks

    OpenAIRE

    Hans ePhaf; Sören Erik Mohr; Mark eRotteveel; Jelte M Wicherts

    2014-01-01

    Approach action tendencies towards positive stimuli and avoidance tendencies from negative stimuli are widely seen to foster survival. Many studies have shown that approach and avoidance arm movements are facilitated by positive and negative affect, respectively. There is considerable debate whether positively and negatively valenced stimuli prime approach and avoidance movements directly (i.e., immediate, unintentional, implicit, automatic, and stimulus-based), or indirectly (i.e., after con...

  15. The inhibitory avoidance discrimination task to investigate accuracy of memory

    NARCIS (Netherlands)

    Atucha Trevino, E.; Roozendaal, B.

    2015-01-01

    The present study was aimed at developing a new inhibitory avoidance task, based on training and/or testing rats in multiple contexts, to investigate accuracy of memory. In the first experiment, male Sprague-Dawley rats were given footshock in an inhibitory avoidance apparatus and, 48 h later, reten

  16. 78 FR 35262 - Detection and Avoidance of Counterfeit Electronic Parts

    Science.gov (United States)

    2013-06-12

    ... about the requirements for detection and avoidance of counterfeit electronic parts in DoD contracts. A proposed rule was published in the Federal Register at 78 FR 28780 on May 16, 2013. The public comment... Defense Acquisition Regulations System Detection and Avoidance of Counterfeit Electronic Parts...

  17. Panic disorder : A baseline period : predictability of agoraphobic avoidance behavior

    NARCIS (Netherlands)

    De Jong, G.Majella; Bouman, Theo K.

    1995-01-01

    This study addresses the relationship between panic symptomatology and situational avoidance behaviour. Eighty panic disordered patients were involved with various degrees of agoraphobia, ranging from nonavoidant to extremely avoidant. Subjects recorded panic attacks by means of a diary for a period

  18. Supercritical self-avoiding walks are space-filling

    CERN Document Server

    Duminil-Copin, Hugo; Yadin, Ariel

    2011-01-01

    We consider random self-avoiding walks between two points on the boundary of a finite subdomain of Z^d (the probability of a self-avoiding trajectory gamma is proportional to mu^{-length(gamma)}). We show that the random trajectory becomes space-filling in the scaling limit when the parameter mu is supercritical.

  19. Quantum walks with tuneable self-avoidance in one dimension

    Science.gov (United States)

    Camilleri, Elizabeth; Rohde, Peter P.; Twamley, Jason

    2014-04-01

    Quantum walks exhibit many unique characteristics compared to classical random walks. In the classical setting, self-avoiding random walks have been studied as a variation on the usual classical random walk. Here the walker has memory of its previous locations and preferentially avoids stepping back to locations where it has previously resided. Classical self-avoiding random walks have found numerous algorithmic applications, most notably in the modelling of protein folding. We consider the analogous problem in the quantum setting - a quantum walk in one dimension with tunable levels of self-avoidance. We complement a quantum walk with a memory register that records where the walker has previously resided. The walker is then able to avoid returning back to previously visited sites or apply more general memory conditioned operations to control the walk. We characterise this walk by examining the variance of the walker's distribution against time, the standard metric for quantifying how quantum or classical a walk is. We parameterise the strength of the memory recording and the strength of the memory back-action on the walker, and investigate their effect on the dynamics of the walk. We find that by manipulating these parameters, which dictate the degree of self-avoidance, the walk can be made to reproduce ideal quantum or classical random walk statistics, or a plethora of more elaborate diffusive phenomena. In some parameter regimes we observe a close correspondence between classical self-avoiding random walks and the quantum self-avoiding walk.

  20. The Infinite Self-Avoiding Walk in High Dimensions

    OpenAIRE

    Lawler, Gregory F.

    1989-01-01

    A measure on infinite self-avoiding walks is defined which is the natural limit of the uniform measure on finite self-avoiding walks. This limit is shown to exist in sufficiently large dimensions using the methods of Slade and Brydges and Spencer.

  1. Supercritical self-avoiding walks are space-filling

    OpenAIRE

    Duminil-Copin, Hugo; Kozma, Gady; Yadin, Ariel

    2014-01-01

    In this article, we consider the following model of self-avoiding walk: the probability of a self-avoiding trajectory $\\gamma$ between two points on the boundary of a finite subdomain of $\\mathbb{Z}^{d}$ is proportional to $\\mu^{-\\mbox{length}(\\gamma)}$. When $\\mu$ is supercritical (i.e. $\\mu

  2. Self-Avoiding Walk is Sub-Ballistic

    Science.gov (United States)

    Duminil-Copin, Hugo; Hammond, Alan

    2013-12-01

    We prove that self-avoiding walk on is sub-ballistic in any dimension d ≥ 2. That is, writing for the Euclidean norm of , and for the uniform measure on self-avoiding walks for which γ 0 = 0, we show that, for each v > 0, there exists such that, for each.

  3. 40 CFR 141.171 - Criteria for avoiding filtration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Criteria for avoiding filtration. 141... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.171 Criteria for avoiding filtration. In addition to...

  4. 40 CFR 141.71 - Criteria for avoiding filtration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Criteria for avoiding filtration. 141... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71 Criteria for avoiding filtration. A public water system that uses a surface water source must meet all...

  5. How to Avoid the ER If You Have Asthma

    Science.gov (United States)

    ... How to Avoid the ER if You Have Asthma KidsHealth > For Teens > How to Avoid the ER if You Have Asthma Print A A A Text Size What's in ... is the last resort for someone who has asthma. If a flare-up is really out of ...

  6. A Robust Obstacle Avoidance for Service Robot Using Bayesian Approach

    Directory of Open Access Journals (Sweden)

    Widodo Budiharto

    2011-03-01

    Full Text Available The objective of this paper is to propose a robust obstacle avoidance method for service robot in indoor environment. The method for obstacles avoidance uses information about static obstacles on the landmark using edge detection. Speed and direction of people that walks as moving obstacle obtained by single camera using tracking and recognition system and distance measurement using 3 ultrasonic sensors. A new geometrical model and maneuvering method for moving obstacle avoidance introduced and combined with Bayesian approach for state estimation. The obstacle avoidance problem is formulated using decision theory, prior and posterior distribution and loss function to determine an optimal response based on inaccurate sensor data. Algorithms for moving obstacles avoidance method proposed and experiment results implemented to service robot also presented. Various experiments show that our proposed method very fast, robust and successfully implemented to service robot called Srikandi II that equipped with 4 DOF arm robot developed in our laboratory.

  7. Multiobjective Optimization Based Vessel Collision Avoidance Strategy Optimization

    Directory of Open Access Journals (Sweden)

    Qingyang Xu

    2014-01-01

    Full Text Available The vessel collision accidents cause a great loss of lives and property. In order to reduce the human fault and greatly improve the safety of marine traffic, collision avoidance strategy optimization is proposed to achieve this. In the paper, a multiobjective optimization algorithm NSGA-II is adopted to search for the optimal collision avoidance strategy considering the safety as well as economy elements of collision avoidance. Ship domain and Arena are used to evaluate the collision risk in the simulation. Based on the optimization, an optimal rudder angle is recommended to navigator for collision avoidance. In the simulation example, a crossing encounter situation is simulated, and the NSGA-II searches for the optimal collision avoidance operation under the Convention on the International Regulations for Preventing Collisions at Sea (COLREGS. The simulation studies exhibit the validity of the method.

  8. Approach, avoidance, and affect: a meta-analysis of approach-avoidance tendencies in manual reaction time tasks

    NARCIS (Netherlands)

    R.H. Phaf; S.E. Mohr; M. Rotteveel; J.M. Wicherts

    2014-01-01

    Approach action tendencies toward positive stimuli and avoidance tendencies from negative stimuli are widely seen to foster survival. Many studies have shown that approach and avoidance arm movements are facilitated by positive and negative affect, respectively. There is considerable debate whether

  9. Reduction in Memory Specificity Following an Approach/Avoidance Scrambled Sentences Task Relates to Cognitive Avoidant Coping

    Science.gov (United States)

    Debeer, Elise; Raes, Filip; Williams, J. Mark G.; Hermans, Dirk

    2013-01-01

    "Overgeneral autobiographical memory" (OGM) refers to the tendency to retrieve less specific personal memories. According to the functional avoidance hypothesis, OGM might act as a cognitive strategy to avoid emotionally distressing details of negative memories. In the present study, we investigated the effect of an experimentally induced avoidant…

  10. Avoidance response of Enchytraeus albidus in relation to carbendazim ageing

    International Nuclear Information System (INIS)

    In this study, avoidance response of Enchytraeus albidus to LUFA 2.2 soil contaminated with pesticide carbendazim was investigated. The aim was to clarify minimal test duration and temporal changes in avoidance response due to contamination ageing. Firstly, the concentration causing 50% avoidance (EC50) was determined as 7.6 mg/kg. Then, test duration needed to reach this value (ET50 = approximately 18 h) was identified. Finally, the capability of E. albidus avoidance test to reflect the changes of pollutant bioavailability was tested. The soil was spiked with carbendazim at the EC50 concentration 1, 14, or 28 days before the test started and avoidance effects of fresh versus aged contamination were compared. The results indicated that enchytraeids preferred soil contaminated for 28 days prior to assay where carbendazim was probably less bioavailable than in freshly spiked soil. Our results open an interesting research area of potential use of avoidance tests for contaminant bioavailability assessment. - The results of this study show that avoidance response of Enchytraeus albidus might identify changes of contaminant bioavailability

  11. Avoidance response of Enchytraeus albidus in relation to carbendazim ageing

    Energy Technology Data Exchange (ETDEWEB)

    Kobeticova, Klara [Research Centre for Environmental Chemistry and Ecotoxicology (RECETOX), Faculty of Science, Masaryk University, Kamenice 126/3, Brno CZ-62500 (Czech Republic)], E-mail: kobeticova@recetox.muni.cz; Hofman, Jakub [Research Centre for Environmental Chemistry and Ecotoxicology (RECETOX), Faculty of Science, Masaryk University, Kamenice 126/3, Brno CZ-62500 (Czech Republic)], E-mail: hofman@recetox.muni.cz; Holoubek, Ivan [Research Centre for Environmental Chemistry and Ecotoxicology (RECETOX), Faculty of Science, Masaryk University, Kamenice 126/3, Brno CZ-62500 (Czech Republic)], E-mail: holoubek@recetox.muni.cz

    2009-02-15

    In this study, avoidance response of Enchytraeus albidus to LUFA 2.2 soil contaminated with pesticide carbendazim was investigated. The aim was to clarify minimal test duration and temporal changes in avoidance response due to contamination ageing. Firstly, the concentration causing 50% avoidance (EC{sub 50}) was determined as 7.6 mg/kg. Then, test duration needed to reach this value (ET{sub 50} = approximately 18 h) was identified. Finally, the capability of E. albidus avoidance test to reflect the changes of pollutant bioavailability was tested. The soil was spiked with carbendazim at the EC{sub 50} concentration 1, 14, or 28 days before the test started and avoidance effects of fresh versus aged contamination were compared. The results indicated that enchytraeids preferred soil contaminated for 28 days prior to assay where carbendazim was probably less bioavailable than in freshly spiked soil. Our results open an interesting research area of potential use of avoidance tests for contaminant bioavailability assessment. - The results of this study show that avoidance response of Enchytraeus albidus might identify changes of contaminant bioavailability.

  12. On the role of subsecond dopamine release in conditioned avoidance

    Directory of Open Access Journals (Sweden)

    Erik B Oleson

    2013-06-01

    Full Text Available Using shock avoidance procedures to study conditioned behavioral responses has a rich history within the field of experimental psychology. Such experiments led to the formulation of the general concept of negative reinforcement and specific theories attempting to explain escape and avoidance behavior, or why animals choose to either terminate or prevent the presentation of an aversive event. For example, the two-factor theory of avoidance holds that cues preceding an aversive event begin to evoke conditioned fear responses, and these conditioned fear responses reinforce the instrumental avoidance response. Current neuroscientific advances are providing new perspectives into this historical literature. Due to its well-established role in reinforcement processes and behavioral control, the mesolimbic dopamine system presented itself as a logical starting point in the search for neural correlates of avoidance and escape behavior. We recently demonstrated that phasic dopamine release events are inhibited by stimuli associated with aversive events but increased by stimuli preceding the successful avoidance of the aversive event. The latter observation is inconsistent with the second component of the two-factor theory of avoidance and; therefore, led us propose a new theoretical explanation of conditioned avoidance: 1 fear is initially conditioned to the warning signal and dopamine computes this fear association as a decrease in release, 2 the warning signal, now capable of producing a negative emotional state, suppresses dopamine release and behavior, 3 over repeated trials the warning signal becomes associated with safety rather than fear; dopaminergic neurons already compute safety as an increase in release and begin to encode the warning signal as the earliest predictor of safety 4 the warning signal now promotes conditioned avoidance via dopaminergic modulation of the brain’s incentive-motivational circuitry.

  13. Self-avoiding walks and polygons on the triangular lattice

    OpenAIRE

    Jensen, Iwan

    2004-01-01

    We use new algorithms, based on the finite lattice method of series expansion, to extend the enumeration of self-avoiding walks and polygons on the triangular lattice to length 40 and 60, respectively. For self-avoiding walks to length 40 we also calculate series for the metric properties of mean-square end-to-end distance, mean-square radius of gyration and the mean-square distance of a monomer from the end points. For self-avoiding polygons to length 58 we calculate series for the mean-squa...

  14. Self-avoiding walks and polygons on quasiperiodic tilings

    International Nuclear Information System (INIS)

    We enumerate self-avoiding walks and polygons, counted by perimeter, on the quasiperiodic rhombic Penrose and Ammann-Beenker tilings, thereby considerably extending previous results. In contrast to similar problems on regular lattices, these numbers depend on the chosen initial vertex. We compare different ways of counting and demonstrate that suitable averaging improves convergence to the asymptotic regime. This leads to improved estimates for critical points and exponents, which support the conjecture that self-avoiding walks on quasiperiodic tilings belong to the same universality class as self-avoiding walks on the square lattice. For polygons, the obtained enumeration data do not allow us to draw decisive conclusions about the exponent

  15. Obstacle-avoidance automatic guidance - A concept-development study

    Science.gov (United States)

    Cheng, Victor H. L.

    1988-01-01

    This paper studies the notion of obstacle-avoidance guidance, and investigates the issues in automating this function by considering helicopter nap-of-the-earth (NOE) flight as an example. In particular, it considers a hierarchy of guidance components, including mission planning and obstacle avoidance. Based on this hierarchical breakdown, the functional requirements of obstacle-avoidance guidance are identified. An effort in developing automatic guidance algorithms to meet these requirements is presented, along with the necesssary simulation tools for evaluation of these algorithms.

  16. ITI-signals and prelimbic cortex facilitate avoidance acquisition and reduce avoidance latencies, respectively, in male WKY rats

    Directory of Open Access Journals (Sweden)

    Kevin D Beck

    2014-11-01

    Full Text Available As a model of anxiety disorder vulnerability, male Wistar-Kyoto (WKY rats acquire lever-press avoidance behavior more readily than outbred Sprague Dawley rats, and their acquisition is enhanced by the presence of a discrete signal presented during the inter-trial intervals (ITIs, suggesting it is perceived as a safety signal. A series of experiments were conducted to determine if this is the case. Additional experiments investigated if the avoidance facilitation relies upon processing through medial prefrontal cortex (mPFC. The results suggest that the ITI-signal facilitates acquisition during the early stages of the avoidance acquisition process, when the rats are initially acquiring escape behavior and then transitioning to avoidance behavior. Post-avoidance introduction of the visual ITI-signal into other associative learning tasks failed to confirm that the visual stimulus had acquired the properties of a conditioned inhibitor. Shortening the signal from the entirety of the 3 min ITI to only the first 5 s of the 3 min ITI slowed acquisition during the first 4 sessions, suggesting the flashing light is not functioning as a feedback signal. The prelimbic (PL cortex showed greater activation during the period of training when the transition from escape responding to avoidance responding occurs. Only combined PL+infralimbic cortex lesions modestly slowed avoidance acquisition, but PL cortex lesions slowed avoidance response latencies. Thus, the flashing light ITI-signal is not likely perceived as a safety signal nor is it serving as a feedback signal. The functional role of the PL cortex appears to be to increase the drive towards responding to the threat of the warning signal. Hence, avoidance susceptibility displayed by male WKY rats may be driven, in part, both by external stimuli (ITI signal as well as by enhanced threat recognition to the warning signal via the PL cortex.

  17. Obstacle Avoidance for Unmanned Undersea Vehicle in Unknown Unstructured Environment

    Directory of Open Access Journals (Sweden)

    Zheping Yan

    2013-01-01

    Full Text Available To avoid obstacle in the unknown environment for unmanned undersea vehicle (UUV, an obstacle avoiding system based on improved vector field histogram (VFH is designed. Forward looking sonar is used to detect the environment, and the divisional sonar modal is applied to deal with the measure uncertainty. To adapt to the VFH, rolling occupancy grids are used for the map building, and high accuracy details of local environment are obtained. The threshold is adaptively adjusted by the statistic of obstacles to solve the problem that VFH is sensitive to threshold. To improve the environment adaptability, the hybrid-behaviors strategy is proposed, which selects the optimal avoidance command according to the motion status and environment character. The simulation shows that UUV could avoid the obstacles fast and escape from the U shape obstacles.

  18. Optical Obstacle Avoidance System for Lunar and Mars Landing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The systems developed at fibertek for Obstacle-Avoidance has so far all been operated at 1560nm. Such an operation is required due to the required eye-safety...

  19. Parents: Avoid Kids Foot Problems with the Right Shoes

    Science.gov (United States)

    ... Bookmark Parents: Avoid kids' foot problems with the right shoes Before you head to the store to ... College of Foot and Ankle Surgeons (ACFAS), All Rights Reserved. | Privacy Statement | Disclaimer | Terms and Conditions | Site ...

  20. AVOIDING RISK IN WORKING CAPITAL CREDIT DISTRIBUTION IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Aloysius Deno Hervino

    2011-09-01

    Full Text Available This research analyzes risk avoidance behaviour of banking institutions in distributing working capital loan in Indonesia. Using Autoregressive Distributed Lag Error Correction Model, this paper uncovers three findings. First, in the short run, risk avoidance in working capital loan distribution depends on inter-call banking money market and Sertifikat Bank Indonesia. Second, following banking regulation after 1997 crisis, banks have become more careful in distributing credits, with SBI as a substitution instrument and inter-call banking money market as a complement instrument to spread the risk. Third, all explanatory variables take an average of 6 days or 1 week to influence bank’s risk avoidance behaviour.Keywords:     Risk avoidance, working capital distribution, banking institutions JEL classification numbers: C32, C52, D81, E51

  1. Parents: Avoid Kids Foot Problems with the Right Shoes

    Science.gov (United States)

    ... Print | Share Avoid Kids Foot Problems with the Right Shoes Before you head to the store to ... College of Foot and Ankle Surgeons (ACFAS), All Rights Reserved. Privacy Statement | Disclaimer | Terms and Conditions | Site ...

  2. Monte Carlo methods for the self-avoiding walk

    Energy Technology Data Exchange (ETDEWEB)

    Janse van Rensburg, E J [Department of Mathematics and Statistics, York University, Toronto, ON M3J 1P3 (Canada)], E-mail: rensburg@yorku.ca

    2009-08-14

    The numerical simulation of self-avoiding walks remains a significant component in the study of random objects in lattices. In this review, I give a comprehensive overview of the current state of Monte Carlo simulations of models of self-avoiding walks. The self-avoiding walk model is revisited, and the motivations for Monte Carlo simulations of this model are discussed. Efficient sampling of self-avoiding walks remains an elusive objective, but significant progress has been made over the last three decades. The model still poses challenging numerical questions however, and I review specific Monte Carlo methods for improved sampling including general Monte Carlo techniques such as Metropolis sampling, umbrella sampling and multiple Markov Chain sampling. In addition, specific static and dynamic algorithms for walks are presented, and I give an overview of recent innovations in this field, including algorithms such as flatPERM, flatGARM and flatGAS. (topical review)

  3. Monte Carlo methods for the self-avoiding walk

    International Nuclear Information System (INIS)

    The numerical simulation of self-avoiding walks remains a significant component in the study of random objects in lattices. In this review, I give a comprehensive overview of the current state of Monte Carlo simulations of models of self-avoiding walks. The self-avoiding walk model is revisited, and the motivations for Monte Carlo simulations of this model are discussed. Efficient sampling of self-avoiding walks remains an elusive objective, but significant progress has been made over the last three decades. The model still poses challenging numerical questions however, and I review specific Monte Carlo methods for improved sampling including general Monte Carlo techniques such as Metropolis sampling, umbrella sampling and multiple Markov Chain sampling. In addition, specific static and dynamic algorithms for walks are presented, and I give an overview of recent innovations in this field, including algorithms such as flatPERM, flatGARM and flatGAS. (topical review)

  4. The Use of Arbitration to Avoid Litigation Under ERISA

    Science.gov (United States)

    Donaldson, Richard P.

    1975-01-01

    In this symposium report it is suggested that arbitration can be used to avoid litigation of ERISA pension and welfare benefit claims if the negotiated plan or related collective bargaining agreement provides for arbitration or benefit disputes. (Author/LBH)

  5. Optimal deadlock avoidance Petri net supervisors for automated manufacturing systems

    Institute of Scientific and Technical Information of China (English)

    Keyi XING; Feng TIAN; Xiaojun YANG

    2007-01-01

    Deadlock avoidance problems are investigated for automated manufacturing systems with flexible routings.Based on the Petri net models of the systems, this paper proposes, for the first time, the concept of perfect maximal resourcetransition circuits and their saturated states. The concept facilitates the development of system liveness characterization and deadlock avoidance Petri net supervisors. Deadlock is characterized as some perfect maximal resource-transition circuits reaching their saturated states. For a large class of manufacturing systems, which do not contain center resources, the optimal deadlock avoidance Petri net supervisors are presented. For a general manufacturing system, a method is proposed for reducing the system Petri net model so that the reduced model does not contain center resources and, hence, has optimal deadlock avoidance Petri net supervisor. The controlled reduced Petri net model can then be used as the liveness supervisor of the system.

  6. You Have Diabetes. How Can You Avoid Serious Eye Diseases?

    Science.gov (United States)

    ... You have diabetes. How can you avoid serious eye diseases? Did you know that diabetic retinopathy, an eye ... loss and other health problems associated with the disease. The National Eye Institute (NEI) offers a guide so you can “ ...

  7. Minding Your Metabolism: Can You Avoid Middle-Age Spread?

    Science.gov (United States)

    ... please review our exit disclaimer . Subscribe Minding Your Metabolism Can You Avoid Middle-Age Spread? As you age, you may notice you have less muscle and energy and more fat. Carrying those extra ...

  8. US Forest Service Aerial Fire Retardant Avoidance Areas: Terrestrial

    Data.gov (United States)

    US Forest Service, Department of Agriculture — A map service depicting aerial fire retardant avoidance areas delivered as part of the 2011 Nationwide Aerial Application of Fire Retardant on National Forest...

  9. Neurobehavioral Study on Social Transmission of Avoidance Behavior

    OpenAIRE

    Masuda, Akira

    2010-01-01

    CHAPTER 1INTRODUCTION||CHAPTER 2BEHAVIORAL STUDIES: BEHAVIORAL CHARACTERISTICS OF THE SOCIAL TRANSMISSION||CHAPTER 3LESION STUDIES: IDENTIFICATION OF IMPORTANT BRAIN AREAS FOR SOCIAL TRANSMISSION OF AVOIDANCE||CHAPTER 4CONCLUSION||Publication List

  10. Gene-culture translation in the avoidance of sibling incest

    OpenAIRE

    Lumsden, Charles J.; Edward O. Wilson

    1980-01-01

    A preliminary analysis is made of the relation between the epigenetic rules of brother-sister incest avoidance, which operate during individual development, and the frequency of occurrence of this form of incest among cultures.

  11. Plans and Measures for Avoiding Casting-Air-Pollution

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jian

    2003-01-01

    This article presents plans of preventing casting-air-pollution in practice, and some avoiding methods in detail. In modern times, environment protection is looked high upon day by day; green-casting thus becomes more and more important.

  12. You Have Diabetes. How Can You Avoid Serious Eye Diseases?

    Science.gov (United States)

    ... Day You have diabetes. How can you avoid serious eye diseases? Did you know that diabetic retinopathy, an eye ... Or that the number of people with this serious eye disease that damages the blood vessels inside the retina, ...

  13. Collision avoidance systems for UAS operating in civil airspace

    OpenAIRE

    Alturbeh, Hamid

    2014-01-01

    Operation of Unmanned Aerial Vehicles (UAVs) in civil airspace is restricted by the aviation authorities which require full compliance with regulations that apply for manned aircraft. This thesis proposes control algorithms for a collision avoidance system that can be used as an advisory system or a guidance system for UAVs that are flying in civil airspace under visual flight rules. An effective collision avoidance system for the UAV should be able to perform the different fun...

  14. Impact of Tactical and Strategic Weather Avoidance on Separation Assurance

    Science.gov (United States)

    Refai, Mohamad S.; Windhorst, Robert

    2011-01-01

    The ability to keep flights away from weather hazards while maintaining aircraft-to-aircraft separation is critically important. The Advanced Airspace Concept is an automation concept that implements a ground-based strategic conflict resolution algorithm for management of aircraft separation. The impact of dynamic and uncertain weather avoidance on this concept is investigated. A strategic weather rerouting system is integrated with the Advanced Airspace Concept, which also provides a tactical weather avoidance algorithm, in a fast time simulation of the Air Transportation System. Strategic weather rerouting is used to plan routes around weather in the 20 minute to two-hour time horizon. To address forecast uncertainty, flight routes are revised at 15 minute intervals. Tactical weather avoidance is used for short term trajectory adjustments (30 minute planning horizon) that are updated every minute to address any weather conflicts (instances where aircraft are predicted to pass through weather cells) that are left unresolved by strategic weather rerouting. The fast time simulation is used to assess the impact of tactical weather avoidance on the performance of automated conflict resolution as well as the impact of strategic weather rerouting on both conflict resolution and tactical weather avoidance. The results demonstrate that both tactical weather avoidance and strategic weather rerouting increase the algorithm complexity required to find aircraft conflict resolutions. Results also demonstrate that tactical weather avoidance is prone to higher airborne delay than strategic weather rerouting. Adding strategic weather rerouting to tactical weather avoidance reduces total airborne delays for the reported scenario by 18% and reduces the number of remaining weather violations by 13%. Finally, two features are identified that have proven important for strategic weather rerouting to realize these benefits; namely, the ability to revise reroutes and the use of maneuvers

  15. Neural correlates of cigarette health warning avoidance among smokers

    OpenAIRE

    Stothart, George; Maynard, Olivia M; Lavis, Rosie J; Munafo, Marcus R.

    2016-01-01

    BACKGROUND: Eye-tracking technology has indicated that daily smokers actively avoid pictorial cigarette package health warnings. Avoidance may be due to a pre-cognitive perceptual bias or a higher order cognitive bias, such as reduced emotional processing. Using electroencephalography (EEG), this study aimed to identify the temporal point at which smokers' responses to health warnings begin to differ.METHOD: Non-smokers (n=20) and daily smokers (n=20) viewed pictorial cigarette package health...

  16. Self-avoiding walks on finite graphs of large girth

    OpenAIRE

    Yadin, Ariel

    2014-01-01

    We consider self-avoiding walk on finite graphs with large girth. We study a few aspects of the model originally considered by Lawler, Schramm and Werner on finite balls in Z^d. The expected length of a random self avoiding path is considered. We also define a "critical exponent" $\\gamma$ for sequences of graphs of size tending to infinity, and show that $\\gamma = 1$ in the large girth case.

  17. Directed self-avoiding walks on a randomly dilute lattice

    OpenAIRE

    Nadal, J.P.; Vannimenus, J.

    1985-01-01

    We consider a model of Directed Self-Avoiding Walks (DSAW) on a dilute lattice, using various approaches (Cayley Tree, weak-disorder expansion, Monte-Carlo generation of walks up to 2 000 steps). This simple model appears to contain the essential features of the controversial problem of self-avoiding walks in a random medium. It is shown in particular that with any amount of disorder the mean value for the number of DSAW is different from its most probable value.

  18. Firm valuation and the uncertainty of future tax avoidance

    OpenAIRE

    Jacob, Martin; Schütt, Harm

    2013-01-01

    The paper studies the effect of uncertainty in tax avoidance on firm value. We first show in a clean surplus valuation model that expected tax rates interact with expectations about future profitability. This paper builds and tests a valuation framework that incorporates two outcome dimensions of corporate tax avoidance strategies: the stability and the level of expected tax rates. We develop a tax planning score that captures these two dimensions. The measure improves the prediction of futur...

  19. Autonomous Visual Navigation and Laser-based Moving Obstacle Avoidance

    OpenAIRE

    Cherubini, Andrea; Spindler, Fabien; Chaumette, François

    2014-01-01

    International audience Moving obstacle avoidance is a fundamental re- quirement for any robot operating in real environments, where pedestrians, bicycles and cars are present. In this paper, we propose and validate a framework for avoiding moving obstacles during visual navigation with a wheeled mobile robot. Visual navigation consists of following a path, represented as an ordered set of key images, which have been acquired by an on-board camera in a teaching phase. While following such p...

  20. Self-Avoiding Random Dynamics on Integer Complex Systems

    OpenAIRE

    Hamze, Firas; Wang, Ziyu; De Freitas, Nando

    2011-01-01

    This paper introduces a new specialized algorithm for equilibrium Monte Carlo sampling of binary-valued systems, which allows for large moves in the state space. This is achieved by constructing self-avoiding walks (SAWs) in the state space. As a consequence, many bits are flipped in a single MCMC step. We name the algorithm SARDONICS, an acronym for Self-Avoiding Random Dynamics on Integer Complex Systems. The algorithm has several free parameters, but we show that Bayesian optimization can ...

  1. The Dual Pathway to Information Avoidance in Information Systems Use

    OpenAIRE

    Neben, Tillmann; Heinzl, Armin; Trenck, Aliona von der

    2013-01-01

    This article develops an explanatory model of information avoidance behavior from extant theory and examines its hypotheses using psychophysiological methods. It integrates existing but partially conflicting explanations into a coherent positivist model based on Coping Theory. The existence of two distinct but interlinked causal pathways to information avoidance will be outlined. Both pathways are cause by defects in the information quality. The first pathway is grounded on being threatened b...

  2. Amygdala involvement in human avoidance, escape and approach behavior

    OpenAIRE

    Schlund, Michael W.; Cataldo, Michael F

    2010-01-01

    Many forms of psychopathology and substance abuse problems are characterized by chronic ritualized forms of avoidance and escape behavior that are designed to control or modify external or internal (i.e, thoughts, emotions, bodily sensations) threats. In this functional magnetic resonance imaging investigation, we examined amygdala reactivity to threatening cues when avoidance responding consistently prevented contact with an upcoming aversive event (money loss). In addition, we examined esca...

  3. Fuzzy Formation Control and Collision Avoidance for Multiagent Systems

    OpenAIRE

    Yeong-Hwa Chang; Chun-Lin Chen; Wei-Shou Chan; Hung-Wei Lin; Chia-Wen Chang

    2013-01-01

    This paper aims to investigate the formation control of leader-follower multiagent systems, where the problem of collision avoidance is considered. Based on the graph-theoretic concepts and locally distributed information, a neural fuzzy formation controller is designed with the capability of online learning. The learning rules of controller parameters can be derived from the gradient descent method. To avoid collisions between neighboring agents, a fuzzy separation controller is proposed suc...

  4. Identity brand avoidance: How is it manifested in social media?

    OpenAIRE

    CHAN KAO CHUNG, Cindy

    2011-01-01

    Existing research on brand symbolic consumption mainly focuses on brand approach; the phenomenon being explained by the theory of self congruity, i.e. consumers would approach brands whose image is congruent to their actual or ideal self. On the other hand, identity brand avoidance, has been object of less attention. The scarce research dedicated to this field essentially revolves around the causes of identity brand avoidance, i.e. when consumers have a positive image of themselves and a nega...

  5. Rouse modes of self-avoiding flexible polymers

    OpenAIRE

    Panja, D.; Barkema, G. T.

    2009-01-01

    Using a lattice-based Monte Carlo code for simulating self-avoiding flexible polymers in three dimensions in the absence of explicit hydrodynamics, we study their Rouse modes. For self-avoiding polymers, the Rouse modes are not expected to be statistically independent; nevertheless, we demonstrate that numerically these modes maintain a high degree of statistical independence. Based on high-precision simulation data we put forward an approximate analytical expression for the mode amplitude co...

  6. Probabilistic Decision Making for Collision Avoidance Systems: Postponing Decisions

    OpenAIRE

    Lefèvre, Stéphanie; Bajcsy, Ruzena; Laugier, Christian

    2013-01-01

    For collision avoidance systems to be accepted by human drivers, it is important to keep the rate of unnecessary interventions very low. This is challenging since the decision to intervene or not is based on incomplete and uncertain information. The contribution of this paper is a decision making strategy for collision avoidance systems which allows the system to occasionally postpone a decision in order to collect more information. The problem is formulated in the framework of statistical de...

  7. Avoidance from petroleum hydrocarbons by the cod (Gadus morhua)

    OpenAIRE

    Bøhle, Bjørn

    1982-01-01

    In laboratory experiments cod was presented a choice situation between different concentrations of petroleum hydrocarbons, appearing as "water soluble fraction" and emulsified droplets derived from Fuel Oil No. 2. In most experiments, the fishes seemed to avoid water containing hydrocarbons, though some fishes for periods was indifferent also to considerable contaminated water. The over all results indicates that a majority of the fishes avoided water containing total hyd...

  8. A bijection to count (1-23-4)-avoiding permutations

    OpenAIRE

    Callan, David

    2010-01-01

    A permutation is (1-23-4)-avoiding if it contains no four entries, increasing left to right, with the middle two adjacent in the permutation. Here we give a 2-variable recurrence for the number of such permutations, improving on the previously known 4-variable recurrence. At the heart of the proof is a bijection from (1-23-4)-avoiding permutations to increasing ordered trees whose leaves, taken in preorder, are also increasing.

  9. UNMANNED AERIAL VEHICLE COLLISION AVOIDANCE USING DIGITAL ELEVATION MODEL

    Directory of Open Access Journals (Sweden)

    Volodymyr Kharchenko

    2013-04-01

    Full Text Available  In the article the important role of Digital Elevation Models for Unmanned Aerial Vehicle collision avoidance and flight planning have been discussed. The web sources of Digital Elevation Models with their descriptions and data transformation procedure for the further processing were represented. The principle of the collision avoidance using Digital Elevation Model has been represented. An obstacle overfly in the vertical plane was shown.

  10. Global and local obstacle avoidance technique for an autonomous vehicle

    Science.gov (United States)

    Gray, Keith W.; Saunders, Kevin S.

    1999-07-01

    The Center for Self-Organizing and Intelligent Systems (CSOIS) is engaged in developing autonomous ground vehicles. A significant problem for such vehicles is obstacle detection and avoidance. After studying various methods of detection, a scanning laser system was chosen that can detect objects at a distance of up to thirty feet while traveling between five and ten miles per hour. Once an object is detected, the vehicle must avoid it. The project employs a mission-level path planner that predetermines the path of a vehicle. One avoidance scheme is to inform the path planner of the obstacle and then let it re-plan the path. This is the global approach to the problem, which allows the use of existing software for maneuvering the vehicle. However, replanning is time consuming and lacks knowledge of the entire obstacle. An alternative approach is to use local avoidance, whereby a vehicle determines how to get by an obstacle without help from the path planner. This approach offers faster response without requiring the computing resource of the path planner. The disadvantage is that during local avoidance the vehicle ignores the global map of known obstacles and does not know to turn control back to the path planner if mission efficiency is adversely affected. This paper will describe a method for combining the current global path planner with a local obstacle avoidance technique to efficiently complete required tasks in a partially unknown environment.

  11. Avoiding Colored Partitions of Lengths Two and Three

    CERN Document Server

    Goyt, Adam M

    2011-01-01

    Pattern avoidance in the symmetric group $S_n$ has provided a number of useful connections between seemingly unrelated problems from stack-sorting to Schubert varieties. Recent work has generalized these results to $S_n\\wr C_c$, the objects of which can be viewed as "colored permutations". Another body of research that has grown from the study of pattern avoidance in permutations is pattern avoidance in $\\Pi_n$, the set of set partitions of $[n]$. Pattern avoidance in set partitions is a generalization of the well-studied notion of noncrossing partitions. Motivated by recent results in pattern avoidance in $S_n \\wr C_c$ we provide a catalog of initial results for pattern avoidance in colored partitions, $\\Pi_n \\wr C_c$. We note that colored set partitions are not a completely new concept. \\emph{Signed} (2-colored) set partitions appear in the work of Bj\\"{o}rner and Wachs involving the homology of partition lattices. However, we seek to study these objects in a new enumerative context.

  12. Attachment avoidance predicts inflammatory responses to marital conflict.

    Science.gov (United States)

    Gouin, Jean-Philippe; Glaser, Ronald; Loving, Timothy J; Malarkey, William B; Stowell, Jeffrey; Houts, Carrie; Kiecolt-Glaser, Janice K

    2009-10-01

    Marital stress has been associated with immune dysregulation, including increased production of interleukin-6 (IL-6). Attachment style, one's expectations about the availability and responsiveness of others in intimate relationships, appears to influence physiological stress reactivity and thus could influence inflammatory responses to marital conflict. Thirty-five couples were invited for two 24-h admissions to a hospital research unit. The first visit included a structured social support interaction, while the second visit comprised the discussion of a marital disagreement. A mixed effect within-subject repeated measure model indicated that attachment avoidance significantly influenced IL-6 production during the conflict visit but not during the social support visit. Individuals with higher attachment avoidance had on average an 11% increase in total IL-6 production during the conflict visit as compared to the social support visit, while individuals with lower attachment avoidance had, on average, a 6% decrease in IL-6 production during the conflict visit as compared to the social support visit. Furthermore, greater attachment avoidance was associated with a higher frequency of negative behaviors and a lower frequency of positive behaviors during the marital interaction, providing a mechanism by which attachment avoidance may influence inflammatory responses to marital conflict. In sum, these results suggest that attachment avoidance modulates marital behavior and stress-induced immune dysregulation. PMID:18952163

  13. Approach, avoidance, and affect: A meta-analysis of approach-avoidance tendencies in manual reaction time tasks

    Directory of Open Access Journals (Sweden)

    Hans ePhaf

    2014-05-01

    Full Text Available Approach action tendencies towards positive stimuli and avoidance tendencies from negative stimuli are widely seen to foster survival. Many studies have shown that approach and avoidance arm movements are facilitated by positive and negative affect, respectively. There is considerable debate whether positively and negatively valenced stimuli prime approach and avoidance movements directly (i.e., immediate, unintentional, implicit, automatic, and stimulus-based, or indirectly (i.e., after conscious or nonconscious interpretation of the situation. The direction and size of these effects were often found to depend on the instructions referring to the stimulus object or the self, and on explicit vs. implicit stimulus evaluation. We present a meta-analysis of 29 studies included for their use of strongly positive and negative stimuli, with 81 effect sizes derived solely from the means and standard deviations (combined N = 1538, to examine the automaticity of the link between affective information processing and approach and avoidance, and to test whether it depends on instruction, type of approach-avoidance task, and stimulus type. Results show a significant small to medium-sized effect after correction for publication bias. The strongest arguments for an indirect link between affect and approach-avoidance were the absence of evidence for an effect with implicit evaluation, and the opposite directions of the effect with self and object-related interpretations. The link appears to be influenced by conscious or nonconscious intentions to deal with affective stimuli.

  14. Java Architecture for Detect and Avoid Extensibility and Modeling

    Science.gov (United States)

    Santiago, Confesor; Mueller, Eric Richard; Johnson, Marcus A.; Abramson, Michael; Snow, James William

    2015-01-01

    Unmanned aircraft will equip with a detect-and-avoid (DAA) system that enables them to comply with the requirement to "see and avoid" other aircraft, an important layer in the overall set of procedural, strategic and tactical separation methods designed to prevent mid-air collisions. This paper describes a capability called Java Architecture for Detect and Avoid Extensibility and Modeling (JADEM), developed to prototype and help evaluate various DAA technological requirements by providing a flexible and extensible software platform that models all major detect-and-avoid functions. Figure 1 illustrates JADEM's architecture. The surveillance module can be actual equipment on the unmanned aircraft or simulators that model the process by which sensors on-board detect other aircraft and provide track data to the traffic display. The track evaluation function evaluates each detected aircraft and decides whether to provide an alert to the pilot and its severity. Guidance is a combination of intruder track information, alerting, and avoidance/advisory algorithms behind the tools shown on the traffic display to aid the pilot in determining a maneuver to avoid a loss of well clear. All these functions are designed with a common interface and configurable implementation, which is critical in exploring DAA requirements. To date, JADEM has been utilized in three computer simulations of the National Airspace System, three pilot-in-the-loop experiments using a total of 37 professional UAS pilots, and two flight tests using NASA's Predator-B unmanned aircraft, named Ikhana. The data collected has directly informed the quantitative separation standard for "well clear", safety case, requirements development, and the operational environment for the DAA minimum operational performance standards. This work was performed by the Separation Assurance/Sense and Avoid Interoperability team under NASA's UAS Integration in the NAS project.

  15. Self-avoiding polygons and walks in slits

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, J; Whittington, S G [Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6 (Canada); Rensburg, E J Janse van [Department of Mathematics and Statistics, York University, Toronto, ON M3J 1P3 (Canada); Soteros, C E [Department of Mathematics and Statistics, University of Saskatchewan, Saskatoon, SK S7N 5E6 (Canada)], E-mail: jalvarez@chem.utoronto.ca, E-mail: rensburg@yorku.ca, E-mail: soteros@math.usask.ca, E-mail: swhittin@chem.utoronto.ca

    2008-05-09

    A polymer in a confined geometry may be modeled by a self-avoiding walk or a self-avoiding polygon confined between two parallel walls. In two dimensions, this model involves self-avoiding walks or self-avoiding polygons in the square lattice between two parallel confining lines. Interactions of the polymer with the confining walls are introduced by energy terms associated with edges in the walk or polygon which are at or near the confining lines. We use transfer-matrix methods to investigate the forces between the walk or polygon and the confining lines, as well as to investigate the effects of the confining slit's width and of the energy terms on the thermodynamic properties of the walks or polygons in several models. The phase diagram found for the self-avoiding walk models is qualitatively similar to the phase diagram of a directed walk model confined between two parallel lines, as was previously conjectured. However, the phase diagram of one of our polygon models is found to be significantly different and we present numerical data to support this. For that particular model we prove that, for any finite values of the energy terms, there are an infinite number of slit widths where a polygon will induce a steric repulsion between the confining lines.

  16. Self-avoiding polygons and walks in slits

    International Nuclear Information System (INIS)

    A polymer in a confined geometry may be modeled by a self-avoiding walk or a self-avoiding polygon confined between two parallel walls. In two dimensions, this model involves self-avoiding walks or self-avoiding polygons in the square lattice between two parallel confining lines. Interactions of the polymer with the confining walls are introduced by energy terms associated with edges in the walk or polygon which are at or near the confining lines. We use transfer-matrix methods to investigate the forces between the walk or polygon and the confining lines, as well as to investigate the effects of the confining slit's width and of the energy terms on the thermodynamic properties of the walks or polygons in several models. The phase diagram found for the self-avoiding walk models is qualitatively similar to the phase diagram of a directed walk model confined between two parallel lines, as was previously conjectured. However, the phase diagram of one of our polygon models is found to be significantly different and we present numerical data to support this. For that particular model we prove that, for any finite values of the energy terms, there are an infinite number of slit widths where a polygon will induce a steric repulsion between the confining lines

  17. Plant adaptation to dynamically changing environment: the shade avoidance response.

    Science.gov (United States)

    Ruberti, I; Sessa, G; Ciolfi, A; Possenti, M; Carabelli, M; Morelli, G

    2012-01-01

    The success of competitive interactions between plants determines the chance of survival of individuals and eventually of whole plant species. Shade-tolerant plants have adapted their photosynthesis to function optimally under low-light conditions. These plants are therefore capable of long-term survival under a canopy shade. In contrast, shade-avoiding plants adapt their growth to perceive maximum sunlight and therefore rapidly dominate gaps in a canopy. Daylight contains roughly equal proportions of red and far-red light, but within vegetation that ratio is lowered as a result of red absorption by photosynthetic pigments. This light quality change is perceived through the phytochrome system as an unambiguous signal of the proximity of neighbors resulting in a suite of developmental responses (termed the shade avoidance response) that, when successful, result in the overgrowth of those neighbors. Shoot elongation induced by low red/far-red light may confer high relative fitness in natural dense communities. However, since elongation is often achieved at the expense of leaf and root growth, shade avoidance may lead to reduction in crop plant productivity. Over the past decade, major progresses have been achieved in the understanding of the molecular basis of shade avoidance. However, uncovering the mechanisms underpinning plant response and adaptation to changes in the ratio of red to far-red light is key to design new strategies to precise modulate shade avoidance in time and space without impairing the overall crop ability to compete for light. PMID:21888962

  18. Providing a food reward reduces inhibitory avoidance learning in zebrafish.

    Science.gov (United States)

    Manuel, Remy; Zethof, Jan; Flik, Gert; van den Bos, Ruud

    2015-11-01

    As shown in male rats, prior history of subjects changes behavioural and stress-responses to challenges: a two-week history of exposure to rewards at fixed intervals led to slightly, but consistently, lower physiological stress-responses and anxiety-like behaviour. Here, we tested whether similar effects are present in zebrafish (Danio rerio). After two weeks of providing Artemia (brine shrimp; Artemia salina) as food reward or flake food (Tetramin) as control at fixed intervals, zebrafish were exposed to a fear-avoidance learning task using an inhibitory avoidance protocol. Half the number of fish received a 3V shock on day 1 and were tested and sacrificed on day 2; the other half received a second 3V shock on day 2 and were tested and sacrificed on day 3. The latter was done to assess whether effects are robust, as effects in rats have been shown to be modest. Zebrafish that were given Artemia showed less inhibitory avoidance after one shock, but not after two shocks, than zebrafish that were given flake-food. Reduced avoidance behaviour was associated with lower telencepahalic gene expression levels of cannabinoid receptor 1 (cnr1) and higher gene expression levels of corticotropin releasing factor (crf). These results suggest that providing rewards at fixed intervals alters fear avoidance behaviour, albeit modestly, in zebrafish. We discuss the data in the context of similar underlying brain structures in mammals and fish. PMID:26342856

  19. Braking news: link between crash severity and crash avoidance maneuvers

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2012-01-01

    This study focused on the link between crash severity and crash avoidance maneuvers. Various emergency lateral and speed control maneuvers were considered in response to different critical events that made the crash imminent. Partial proportional odds models that allowed for changes in effects...... across severity levels were estimated to accommodate the ordered-response nature of severity. The sample used for estimation consisted of data for single-vehicle crashes extracted from the General Estimates System crash database for the period from 2005 to 2009. Results showed the correlation between...... crash avoidance maneuvers and crash severity, with differences emerging for different critical events. Moreover, results showed two trends:(a) most drivers failed to act when facing critical events and (b) drivers rarely performed crash avoidance maneuvers that were correlated with a higher probability...

  20. Dynamic Obstacle Avoidance for an Omnidirectional Mobile Robot

    Directory of Open Access Journals (Sweden)

    Robert L. Williams

    2010-01-01

    Full Text Available We have established a novel method of obstacle-avoidance motion planning for mobile robots in dynamic environments, wherein the obstacles are moving with general velocities and accelerations, and their motion profiles are not preknown. A hybrid system is presented in which a global deliberate approach is applied to determine the motion in the desired path line (DPL, and a local reactive approach is used for moving obstacle avoidance. A machine vision system is required to sense obstacle motion. Through theoretical analysis, simulation, and experimental validation applied to the Ohio University RoboCup robot, we show the method is effective to avoid collisions with moving obstacles in a dynamic environment.

  1. Effective Congestion Avoidance Scheme for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Ramachandra.V.Pujeri

    2013-01-01

    Full Text Available Mobile nodes are organized randomly without any access point in Mobile Ad hoc Networks (MANETs. Due to the mobility of nodes, the network congestion occurs. So many congestion control mechanisms were proposed to avoid the congestion avoidance or reducing the congestion status. In this research work, we proposed to develop the Effective Congestion Avoidance Scheme (ECAS, which consists of congestion monitoring, effective routing establishment and congestionless based routing. The overall congestion status is measured in congestion monitoring. In routing establishment, we propose the contention metric in the particular channel in terms of, queue length of packet, overall congestion standard, packet loss rate and packet dropping ratio to monitor the congestion status. Based on the congestion standard, the congestionless based routing is established to reduce the packet loss, high overhead, long delay in the network. By extensive simulation, the proposed scheme achieves better throughput, packet delivery ratio, low end-to-end delay and overhead than the existing schemes.

  2. A neuro-collision avoidance strategy for robot manipulators

    Science.gov (United States)

    Onema, Joel P.; Maclaunchlan, Robert A.

    1992-01-01

    The area of collision avoidance and path planning in robotics has received much attention in the research community. Our study centers on a combination of an artificial neural network paradigm with a motion planning strategy that insures safe motion of the Articulated Two-Link Arm with Scissor Hand System relative to an object. Whenever an obstacle is encountered, the arm attempts to slide along the obstacle surface, thereby avoiding collision by means of the local tangent strategy and its artificial neural network implementation. This combination compensates the inverse kinematics of a robot manipulator. Simulation results indicate that a neuro-collision avoidance strategy can be achieved by means of a learning local tangent method.

  3. Generalized atmospheric sampling of self-avoiding walks

    International Nuclear Information System (INIS)

    In this paper, we introduce a new Monte Carlo method for sampling lattice self-avoiding walks. The method, which we call 'GAS' (generalized atmospheric sampling), samples walks along weighted sequences by implementing elementary moves generated by the positive, negative and neutral atmospheric statistics of the walks. A realized sequence is weighted such that the average weight of states of length n is proportional to the number of self-avoiding walks from the origin cn. In addition, the method also self-tunes to sample from uniform distributions over walks of lengths in an interval [0, nmax]. We show how to implement GAS using both generalized and endpoint atmospheres of walks and analyse our data to obtain estimates of the growth constant and entropic exponent of self-avoiding walks in the square and cubic lattices.

  4. Generalized atmospheric sampling of self-avoiding walks

    Energy Technology Data Exchange (ETDEWEB)

    Van Rensburg, E J Janse [Department of Mathematics and Statistics, York University Toronto, Ontario M3J 1P3 (Canada); Rechnitzer, A [Department of Mathematics, University of British Columbia, Vancouver, British Columbia V6T 1Z2 (Canada)], E-mail: rensburg@yorku.ca, E-mail: andrewr@math.ubc.ca

    2009-08-21

    In this paper, we introduce a new Monte Carlo method for sampling lattice self-avoiding walks. The method, which we call 'GAS' (generalized atmospheric sampling), samples walks along weighted sequences by implementing elementary moves generated by the positive, negative and neutral atmospheric statistics of the walks. A realized sequence is weighted such that the average weight of states of length n is proportional to the number of self-avoiding walks from the origin c{sub n}. In addition, the method also self-tunes to sample from uniform distributions over walks of lengths in an interval [0, n{sub max}]. We show how to implement GAS using both generalized and endpoint atmospheres of walks and analyse our data to obtain estimates of the growth constant and entropic exponent of self-avoiding walks in the square and cubic lattices.

  5. A robot arm controller with obstacle avoidance using fuzzy logic

    International Nuclear Information System (INIS)

    This study is devoted to the development of a lower level robot arm control system, which allows obstacles to be avoided using a relatively rough path and without precise map information. To achieve autonomous arm movements, the overall arm motion is divided into an obstacle avoidance component and a target point adjustment component, and movement is selected with regard to the distance between the arm and the obstacle by a higher control unit. A fuzzy rule is used for mode selection in order to maintain continuous change of control mode. The control method applied to two degrees of freedom in two dimensional space was examined by numerical simulations. The simulations verified the autonomous obstacle avoidance capability and the ability to continuously control joint angles using fuzzy logic. (author)

  6. Predictive Potential Field-Based Collision Avoidance for Multicopters

    Science.gov (United States)

    Nieuwenhuisen, M.; Schadler, M.; Behnke, S.

    2013-08-01

    Reliable obstacle avoidance is a key to navigating with UAVs in the close vicinity of static and dynamic obstacles. Wheel-based mobile robots are often equipped with 2D or 3D laser range finders that cover the 2D workspace sufficiently accurate and at a high rate. Micro UAV platforms operate in a 3D environment, but the restricted payload prohibits the use of fast state-of-the-art 3D sensors. Thus, perception of small obstacles is often only possible in the vicinity of the UAV and a fast collision avoidance system is necessary. We propose a reactive collision avoidance system based on artificial potential fields, that takes the special dynamics of UAVs into account by predicting the influence of obstacles on the estimated trajectory in the near future using a learned motion model. Experimental evaluation shows that the prediction leads to smoother trajectories and allows to navigate collision-free through passageways.

  7. Modeling and Simulation of an UAS Collision Avoidance Systems

    Science.gov (United States)

    Oliveros, Edgardo V.; Murray, A. Jennifer

    2010-01-01

    This paper describes a Modeling and Simulation of an Unmanned Aircraft Systems (UAS) Collision Avoidance System, capable of representing different types of scenarios for UAS collision avoidance. Commercial and military piloted aircraft currently utilize various systems for collision avoidance such as Traffic Alert and Collision A voidance System (TCAS), Automatic Dependent Surveillance-Broadcast (ADS-B), Radar and ElectroOptical and Infrared Sensors (EO-IR). The integration of information from these systems is done by the pilot in the aircraft to determine the best course of action. In order to operate optimally in the National Airspace System (NAS) UAS have to work in a similar or equivalent manner to a piloted aircraft by applying the principle of "detect-see and avoid" (DSA) to other air traffic. Hence, we have taken these existing sensor technologies into consideration in order to meet the challenge of researching the modeling and simulation of an approximated DSA system. A Schematic Model for a UAS Collision Avoidance System (CAS) has been developed ina closed loop block diagram for that purpose. We have found that the most suitable software to carry out this task is the Satellite Tool Kit (STK) from Analytical Graphics Inc. (AGI). We have used the Aircraft Mission Modeler (AMM) for modeling and simulation of a scenario where a UAS is placed on a possible collision path with an initial intruder and then with a second intruder, but is able to avoid them by executing a right tum maneuver and then climbing. Radars have also been modeled with specific characteristics for the UAS and both intruders. The software provides analytical, graphical user interfaces and data controlling tools which allow the operator to simulate different conditions. Extensive simulations have been carried out which returned excellent results.

  8. A Study of MMW Collision Avoidance Radar System for Trains

    Directory of Open Access Journals (Sweden)

    Liu Hai-bo

    2013-06-01

    Full Text Available Collision avoidance radar for trains is pregnant for safety transportation. In order to realize low cost and high performance of azimuth accuracy, we have developed MMW (Milli-Meter Wave radar, which employs switched phased array and frequency stepped technology. This paper analyses the radiation patterns of transmitting/receiving antennas and compensation method for amplitude/phase errors of synthetic wideband frequency stepped signal. To confirm the operation of the radar, low cost millimeter-wave collision avoidance radar was fabricated. Lots of experiments confirmed a high azimuth and range resolution.

  9. Formation and obstacle avoidance control for multiagent systems

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper considers the problems of formation and obstacle avoidance for multiagent systems.The objective is to design a term of agents that can reach a desired formation while avoiding collision with obstacles.To reduce the amount of information interaction between agents and target,we adopt the leader-follower formation strategy.By using the receding horizon control (RHC),an optimal problem is formulated in terms of cost minimization under constraints.Information on obstacles is incorporated online as se...

  10. Self-organization and self-avoiding limit cycles

    Science.gov (United States)

    Hexner, D.; Levine, D.

    2015-02-01

    A simple periodically driven system displaying rich behavior is introduced and studied. The system self-organizes into a mosaic of static ordered regions with three possible patterns, which are threaded by one-dimensional paths on which a small number of mobile particles travel. These trajectories are self-avoiding and non-intersecting, and their relationship to self-avoiding random walks is explored. Near ρ=0.5 the distribution of path lengths becomes power-law-like up to some cutoff length, suggesting a possible critical state.

  11. Structural characterization of ice polymorphs from self-avoiding walks

    OpenAIRE

    Herrero, Carlos P.

    2014-01-01

    Topological properties of crystalline ice structures are studied by means of self-avoiding walks on their H-bond networks. The number of self-avoiding walks, C_n, for eight ice polymorphs has been obtained by direct enumeration up to walk length n = 27. This has allowed us to determine the `connective constant' or effective coordination number `mu' of these structures as the limit of the ratio C_n/C_{n-1} for large n. This structure-dependent parameter `mu' is related with other topological c...

  12. Peculiar Scaling of Self-Avoiding Walk Contacts

    International Nuclear Information System (INIS)

    The nearest neighbor contacts between the two halves of an N -site lattice self-avoiding walk offer an unusual example of scaling random geometry: for N→∞ they are strictly finite in number but their radius of gyration Rc is power law distributed ∝R-τc, where τ>1 is a novel exponent characterizing universal behavior. A continuum of diverging length scales is associated with the Rc distribution. A possibly superuniversal τ=2 is also expected for the contacts of a self-avoiding or random walk with a confining wall

  13. Enumeration of self-avoiding walks on the square lattice

    OpenAIRE

    Jensen, Iwan

    2004-01-01

    We describe a new algorithm for the enumeration of self-avoiding walks on the square lattice. Using up to 128 processors on a HP Alpha server cluster we have enumerated the number of self-avoiding walks on the square lattice to length 71. Series for the metric properties of mean-square end-to-end distance, mean-square radius of gyration and mean-square distance of monomers from the end points have been derived to length 59. Analysis of the resulting series yields accurate estimates of the cri...

  14. The critical pulling force for self-avoiding walks

    OpenAIRE

    Beaton, Nicholas R.

    2014-01-01

    Self-avoiding walks are a simple and well-known model of long, flexible polymers in a good solvent. Polymers being pulled away from a surface by an external agent can be modelled with self-avoiding walks in a half-space, with a Boltzmann weight $y = e^f$ associated with the pulling force. This model is known to have a critical point at a certain value $y_c$ of this Boltzmann weight, which is the location of a transition between the so-called free and ballistic phases. The value $y_c=1$ has be...

  15. Multifractality of self-avoiding walks on percolation clusters.

    Science.gov (United States)

    Blavatska, Viktoria; Janke, Wolfhard

    2008-09-19

    We consider self-avoiding walks on the backbone of percolation clusters in space dimensions d=2,3,4. Applying numerical simulations, we show that the whole multifractal spectrum of singularities emerges in exploring the peculiarities of the model. We obtain estimates for the set of critical exponents that govern scaling laws of higher moments of the distribution of percolation cluster sites visited by self-avoiding walks, in a good correspondence with an appropriately summed field-theoretical epsilon=6-d expansion [H.-K. Janssen and O. Stenull, Phys. Rev. E 75, 020801(R) (2007)10.1103/PhysRevE.75.020801]. PMID:18851389

  16. Self-avoiding walk is sub-ballistic

    CERN Document Server

    Duminil-Copin, Hugo

    2012-01-01

    We prove that self-avoiding walk on Z^d is sub-ballistic in any dimension d at least two. That is, writing ||u|| for the Euclidean norm of u \\in Z^d, and SAW_n for the uniform measure on self-avoiding walks gamma:{0,...,n} \\to Z^d for which gamma_0 = 0, we show that, for each v > 0, there exists c > 0 such that, for each positive integer n, SAW_n (max {|| gamma_k || : k \\in {0,...,n}} > v n) < e^{- c n}.

  17. Managed care contracting and payment reform: avoiding a showdown.

    Science.gov (United States)

    Nugent, Michael E

    2010-07-01

    Health reform promises to fundamentally change what and how CMS and commercial payers reimburse providers. Providers need to transition from their traditionally adversarial, transactions-based payer relationships to ones that optimize purchaser and patient value for the dollar. To avoid negotiation table showdowns and to prepare for reform, commercial payers and providers should take three actions: Recognize the dead ends with their historical relationships. Formulate their road map to value-based contracting. Avoid operational pot-holes along the way. PMID:20608414

  18. OBSTACLE-AVOIDANCE NAVIGATION OF MULTIPLE MOBILE ROBOTS

    Institute of Scientific and Technical Information of China (English)

    罗青; 李智军; 吕恬生

    2002-01-01

    In the context of robot soccer, the robots have to select actions to achieve individual and team goals in the dynamic environment. It is important for a robot to acquire navigation behaviors for avoiding other robots and obstacles in the real-time environment. This paper suggested an efficient approach to collision-avoidance in multirobot system. This approach is based on velocity information of moving objects and the distance between robot and obstacle in three specified directions. The main contribution of this paper is that it provides a method for robots with decreased-computational cost and makes the robot navigate without collision with each other in a complicated environment.

  19. A Hands-Free Obstacle Detection and Avoidance System

    Directory of Open Access Journals (Sweden)

    M. Abdul-Niby

    2015-06-01

    Full Text Available In this paper, we present a low cost hands-free detection and avoidance system designed to provide mobility assistance for visually impaired people. An ultrasonic sensor is attached to the jacket of the user and detects the obstacles in front. The information obtained is transferred to the user through audio messages and also by a vibration. The range of the detection is user-defined. A text-to-speech module is employed for the voice signal. The proposed obstacle avoidance device is cost effective, easy to use and easily upgraded.

  20. The "Eye Avoidance" Hypothesis of Autism Face Processing.

    Science.gov (United States)

    Tanaka, James W; Sung, Andrew

    2016-05-01

    Although a growing body of research indicates that children with autism spectrum disorder (ASD) exhibit selective deficits in their ability to recognize facial identities and expressions, the source of their face impairment is, as yet, undetermined. In this paper, we consider three possible accounts of the autism face deficit: (1) the holistic hypothesis, (2) the local perceptual bias hypothesis and (3) the eye avoidance hypothesis. A review of the literature indicates that contrary to the holistic hypothesis, there is little evidence to suggest that individuals with autism do perceive faces holistically. The local perceptual bias account also fails to explain the selective advantage that ASD individuals demonstrate for objects and their selective disadvantage for faces. The eye avoidance hypothesis provides a plausible explanation of face recognition deficits where individuals with ASD avoid the eye region because it is perceived as socially threatening. Direct eye contact elicits a increased physiological response as indicated by heightened skin conductance and amygdala activity. For individuals with autism, avoiding the eyes is an adaptive strategy, however, this approach interferes with the ability to process facial cues of identity, expressions and intentions, exacerbating the social challenges for persons with ASD. PMID:24150885

  1. Nine Easy Steps to Avoiding Software Copyright Infringement.

    Science.gov (United States)

    Gamble, Lanny R.; Anderson, Larry S.

    1989-01-01

    To avoid microcomputer software copyright infringement, administrators must be aware of the law, read the software agreements, maintain good records, submit all software registration cards, provide secure storage, post warnings, be consistent when establishing and enforcing policies, consider a site license, and ensure the legality of currently…

  2. Time Pressure Undermines Performance More Under Avoidance Than Approach Motivation

    NARCIS (Netherlands)

    Roskes, Marieke; Elliot, Andrew J.; Nijstad, Bernard A.; De Dreu, Carsten K. W.

    2013-01-01

    Four experiments were designed to test the hypothesis that performance is particularly undermined by time pressure when people are avoidance motivated. The results supported this hypothesis across three different types of tasks, including those well suited and those ill suited to the type of informa

  3. Tax avoidance with cross-border hybrid instruments

    DEFF Research Database (Denmark)

    Johannesen, Niels

    2014-01-01

    The rules demarcating debt and equity for tax purposes differ between countries, hence the possibility that a hybrid financial instrument is treated as equity in one country and debt in another. This may create a scope for tax avoidance by allowing firms that invest in foreign countries to combine...

  4. Obstacle Avoidance in Groping Locomotion of a Humanoid Robot

    Directory of Open Access Journals (Sweden)

    Masahiro Ohka

    2008-11-01

    Full Text Available This paper describes the development of an autonomous obstacle-avoidance method that operates in conjunction with groping locomotion on the humanoid robot Bonten-Maru II. Present studies on groping locomotion consist of basic research in which humanoid robot recognizes its surroundings by touching and groping with its arm on the flat surface of a wall. The robot responds to the surroundings by performing corrections to its orientation and locomotion direction. During groping locomotion, however, the existence of obstacles within the correction area creates the possibility of collisions. The objective of this paper is to develop an autonomous method to avoid obstacles in the correction area by applying suitable algorithms to the humanoid robot's control system. In order to recognize its surroundings, six-axis force sensors were attached to both robotic arms as end effectors for force control. The proposed algorithm refers to the rotation angle of the humanoid robot's leg joints due to trajectory generation. The algorithm relates to the groping locomotion via the measured groping angle and motions of arms. Using Bonten-Maru II, groping experiments were conducted on a wall's surface to obtain wall orientation data. By employing these data, the humanoid robot performed the proposed method autonomously to avoid an obstacle present in the correction area. Results indicate that the humanoid robot can recognize the existence of an obstacle and avoid it by generating suitable trajectories in its legs.

  5. Conformal Invariance of the 3D Self-Avoiding Walk

    Science.gov (United States)

    Kennedy, Tom

    2013-10-01

    We show that if the three-dimensional self-avoiding walk (SAW) is conformally invariant, then one can compute the hitting densities for the SAW in a half-space and in a sphere. We test these predictions by Monte Carlo simulations and find excellent agreement, thus providing evidence that the SAW is conformally invariant in three dimensions.

  6. Self-Avoiding Walks (SAWs), Entanglement and Biomolecules

    DEFF Research Database (Denmark)

    Hansen, Mikael Sonne

    2006-01-01

    The Self-Avoiding Walk (SAW) on a lattice are often used to study properties of polymers in good solvents such as entanglement, knotting (ring polymers), and statistical mechanical properties of polymers. Recently it has been used to explain the increased probability of phage DNA being knotted when...

  7. Flory approximant for self-avoiding walks on fractals

    International Nuclear Information System (INIS)

    A Flory approximat for the exponent describing the end-to-end distance of a self-avoiding walk (SAW) on fractals is derived. The approximat involves the fractal dimensionalities of the backbone and of the minimal path, and the exponent describing the resistance of the fractal. The approximant yields values which are very close to those available from exact and numerical calculations

  8. Self Avoiding Walks in Four Dimensions: Logarithmic Corrections

    OpenAIRE

    Grassberger, Peter; Hegger, Rainer; Schaefer, Lothar

    1994-01-01

    We present simulation results for long ($N\\leq 4000$) self-avoiding walks in four dimensions. We find definite indications of logarithmic corrections, but the data are poorly described by the asymptotically leading terms. Detailed comparisons are presented with renormalization group flow equations derived in direct renormalization and with results of a field theoretic calculation.

  9. The persistence length of two dimensional self avoiding random walks

    OpenAIRE

    Eisenberg, E.; Baram, A.

    2002-01-01

    The decay of directional correlations in self-avoiding random walks on the square lattice is investigated. Analysis of exact enumerations and Monte Carlo data suggest that the correlation between the directions of the first step and the j-th step of the walk decays faster than 1/j, indicating that the persistence length of the walk is finite.

  10. The Fixed Irreducible Bridge Ensemble for Self-Avoiding Walks

    Science.gov (United States)

    Gilbert, Michael James

    2015-04-01

    We define a new ensemble for self-avoiding walks in the upper half-plane, the fixed irredicible bridge ensemble, by considering self-avoiding walks in the upper half-plane up to their -th bridge height, , and scaling the walk by to obtain a curve in the unit strip, and then taking . We then conjecture a relationship between this ensemble to in the unit strip from 0 to a fixed point along the upper boundary of the strip, integrated over the conjectured exit density of self-avoiding walk spanning a strip in the scaling limit. We conjecture that there exists a positive constant such that converges in distribution to that of a stable random variable as . Then the conjectured relationship between the fixed irreducible bridge scaling limit and can be described as follows: If one takes a SAW considered up to and scales by and then weights the walk by to an appropriate power, then in the limit , one should obtain a curve from the scaling limit of the self-avoiding walk spanning the unit strip. In addition to a heuristic derivation, we provide numerical evidence to support the conjecture and give estimates for the boundary scaling exponent.

  11. Improving Network Performance using ACO Based Redundant Link Avoidance Algorithm

    Directory of Open Access Journals (Sweden)

    B. Chandra Mohan

    2010-05-01

    Full Text Available In the wide spread internet, response time and pocket loss are inappropriate due to network traffic, as a result the network efficiency becomes worst and the system provides poor Quality of Service (QoS. An optimal routing protocol, especially multipath may avoid such traffic in the network. But existing routing protocols, both single path and multi path, concentrates only on finding the routes based on any one or some set of metrics, that not always suitable for dynamic, cloud natured network environment. Ant Colony Optimization (ACO based multipath routing protocol was suggested as an alternate to this problem by many researchers. The multipath ACO also provides same set of link(s for the source to destination, so that traffic merging again becomes a critical problem. This paper proposes an optimal solution to avoid the problem of traffic merging in the network by removing redundant link in the route. The Proposed algorithm, called 'Redundant Link Avoidance (RLA algorithm', is an ACO based multi path routing methodology, avoiding copious link in the suggested routes of ACO multipath protocol.

  12. Career Barriers: How People Experience, Overcome, and Avoid Failure.

    Science.gov (United States)

    London, Manuel

    This book defines career barriers, considers how people react to them, and offers ways to overcome and prevent them. It is geared towards people experiencing career barriers; for students at the start of their careers; for seasoned employees wanting to avoid or be prepared to deal with career barriers; and for managers, human resource…

  13. Enuresis Control through Fading, Escape, and Avoidance Training.

    Science.gov (United States)

    Hansen, Gordon D.

    1979-01-01

    A twin signal device that provides both escape and avoidance conditioning in enuresis control was documented with case studies of two enuretic children (eight and nine years old). In addition, a technique of fading as an adjunct to the process was utilized with one subject. (Author/SBH)

  14. Information Seeking and Avoidance Behavior in School Library Distance Learning

    Science.gov (United States)

    Du, Yunfei

    2010-01-01

    Library science students in school librarianship were surveyed to determine their information seeking and avoidance behaviors in Web-based online environments. Two coping styles were identified among students. Barriers to student online collaboration, such as individual preferences, concerns on efficiency, and lack of mutual trust, were observed.…

  15. Packet Drop Avoidance for High-speed network transmission protocol

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Guojun

    2004-05-01

    As network bandwidth continues to grow and longer paths are used to exchange large scientific data between storage systems and GRID computation, it has become increasingly obvious that there is a need to deploy a packet drop avoidance mechanism into network transmission protocols. Current end-to-end congestion avoidance mechanisms used in Transmission Control Protocol (TCP) have worked well on low bandwidth delay product networks, but with newer high-bandwidth delay networks they have shown to be inefficient and prone to unstable. This is largely due to increased network bandwidth coupled with changes in internet traffic patterns. These changes come from a variety of new network applications that are being developed to take advantage of the increased network bandwidth. This paper will examine the end-to-end congestion avoidance mechanism and perform a step-by-step analysis of its theory. In addition we will propose an alternative approach developed as part of a new network transmission protocol. Our alternative protocol uses a packet drop avoidance (PDA) mechanism built on top of the maximum burst size (MBS) theory combined with a real-time available bandwidth algorithm.

  16. 50 CFR 600.510 - Gear avoidance and disposal.

    Science.gov (United States)

    2010-10-01

    ... fishery in which the FFV is engaged. (b) Gear conflicts. The operator of each FFV that is involved in a... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear avoidance and disposal. 600.510 Section 600.510 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC...

  17. Accident Avoidance Skill Training and Performance Testing. Final Report.

    Science.gov (United States)

    Hatterick, G. Richard; Barthurst, James R.

    A two-phased study was conducted to determine the feasibility of training drivers to acquire skills needed to avoid critical conflict motor vehicle accidents, and to develop the procedures and materials necessary for such training. Basic data were derived from indepth accident investigations and task analyses of driver behavior. Principal…

  18. Binge Eating and Weight Control: The Role of Experiential Avoidance

    Science.gov (United States)

    Lillis, Jason; Hayes, Steven C.; Levin, Michael E.

    2011-01-01

    Two thirds of the adults in the United States are overweight or obese. Binge eating is a barrier to treatment adherence and sustained weight loss, and can be seen as a form of experiential avoidance. The current study analyzed the impact of binge eating on weight reduction in a previously published study of a 1-day acceptance and commitment…

  19. Concept development of automatic guidance for rotorcraft obstacle avoidance

    Science.gov (United States)

    Cheng, Victor H. L.

    1990-01-01

    The automatic guidance of rotorcraft for obstacle avoidance in nap-of-the-earth flight is studied. A hierarchical breakdown of the guidance components is used to identify the functional requirements. These requirements and anticipated sensor capabilities lead to a preliminary guidance concept, which has been evaluated via computer simulations.

  20. Robot vision: obstacle-avoidance techniques for unmanned aerial vehicles

    NARCIS (Netherlands)

    Carloni, Raffaella; Lippiello, Vincenzo; D'auria, Massimo; Fumagalli, Matteo; Mersha, Abeje Y.; Stramigioli, Stefano; Sicilano, Bruno

    2013-01-01

    In this article, a vision-based technique for obstacle avoidance and target identification is combined with haptic feedback to develop a new teleoperated navigation system for underactuated aerial vehicles in unknown environments. A three-dimensional (3-D) map of the surrounding environment is built

  1. Food aquisition and predator avoidance in a Neotropical rodent

    NARCIS (Netherlands)

    Suselbeek, L.; Emsens, W.J.; Hirsch, B.T.; Kays, R.; Rowcliffe, J.M.; Zamore-Gutierrez, V.; Jansen, P.A.

    2014-01-01

    Foraging activity in animals reflects a compromise between acquiring food and avoiding predation. The Risk Allocation Hypothesis predicts that prey animals optimize this balance by concentrating their foraging activity at times of relatively low predation risk, as much as their energy status permits

  2. Avoiding asymmetry-induced bias in longitudinal image processing

    OpenAIRE

    Reuter, Martin; Fischl, Bruce

    2011-01-01

    Longitudinal image processing procedures frequently transfer or pool information across time within subject, with the dual goals of reducing the variability and increasing the accuracy of the derived measures. In this note, we discuss common difficulties in longitudinal image processing, focusing on the introduction of bias, and describe the approaches we have taken to avoid them in the FreeSurfer longitudinal processing stream.

  3. Fish avoidance of acoustic survey boat in shallow waters

    Czech Academy of Sciences Publication Activity Database

    Draštík, Vladislav; Kubečka, Jan

    2005-01-01

    Roč. 72, 2-3 (2005), s. 219-228. ISSN 0165-7836 R&D Projects: GA AV ČR(CZ) IAA6017901; GA AV ČR(CZ) IBS6017004 Institutional research plan: CEZ:AV0Z6017912 Keywords : fish behaviour * avoidance * echogram slope Subject RIV: EH - Ecology, Behaviour Impact factor: 1.160, year: 2005

  4. Avoiding Childhood Obesity (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2013-01-31

    Maintaining a healthy weight in childhood can prevent many health-related problems later in life. In this podcast, Dr. Jackson Sekhobo discusses the importance of avoiding obesity in childhood.  Created: 1/31/2013 by MMWR.   Date Released: 1/31/2013.

  5. Avoiding School Management Conflicts and Crisis through Formal Communication

    Science.gov (United States)

    Nwogbaga, David M. E.; Nwankwo, Oliver U.; Onwa, Doris O.

    2015-01-01

    This paper examined how conflicts and crisis can be avoided through formal communication. It was necessitated by the observation that most of the conflicts and crisis which tend to mar school management today are functions of the inconsistencies arising from "grapevines, rumours, and gossips" generated through informal communication…

  6. A Simple Method for Thoracotomy Closure Avoiding Intercostal Nerve Damage

    OpenAIRE

    Ufuk Cagirici

    2014-01-01

    It is well known that intercostal nerve damage during thoracotomy closure causes severe postoperative pain. A simple closure technique is proposed for intercostal nerve-sparing during thoracotomy opening and closure. We think that this maneuver may avoid intercostal nerve compression.

  7. Avoid Vaccine Administration Errors with Seven Simple Steps

    Centers for Disease Control (CDC) Podcasts

    2012-02-16

    This podcast discusses seven simple ways to avoid vaccine administration errors in health care settings.  Created: 2/16/2012 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 2/16/2012.

  8. Summary of avoidable cancers in the Nordic countries

    DEFF Research Database (Denmark)

    Olsen, J H; Andersen, A; Dreyer, L;

    1997-01-01

    An overview is given of the most important known causes of cancer in the five Nordic countries and the resulting number of cancers that are potentially avoidable. The main causes include active and passive smoking, alcohol consumption, exposure to asbestos and other occupational carcinogens, solar...

  9. A Note on Risk Acceptance, Bankruptcy Avoidance and Riskiness Measures

    OpenAIRE

    Chamorro Elosua, Arritokieta; Usategui Díaz de Otalora, José María

    2013-01-01

    In this work we clarify the relationships between riskiness, risk acceptance and bankruptcy avoidance. We distinguish between the restriction on the current wealth required to make a gamble acceptable to the decision maker and the restriction on the current wealth required to guarantee no bankruptcy if a gamble is accepted. We focus on the measure of riskiness proposed by Foster and Hart.

  10. Fear-avoidance beliefs and pain avoidance in low back pain--translating research into clinical practice

    DEFF Research Database (Denmark)

    Rainville, James; Smeets, Rob J E M; Bendix, Tom; Tveito, Torill H; Poiraudeau, Serge; Indahl, Aage J

    2011-01-01

    For patients with low back pain, fear-avoidance beliefs (FABs) represent cognitions and emotions that underpin concerns and fears about the potential for physical activities to produce pain and further harm to the spine. Excessive FABs result in heightened disability and are an obstacle for recov...... recovery from acute, subacute, and chronic low back pain.......For patients with low back pain, fear-avoidance beliefs (FABs) represent cognitions and emotions that underpin concerns and fears about the potential for physical activities to produce pain and further harm to the spine. Excessive FABs result in heightened disability and are an obstacle for...

  11. Recurrent, robust and scalable patterns underlie human approach and avoidance.

    Directory of Open Access Journals (Sweden)

    Byoung Woo Kim

    Full Text Available BACKGROUND: Approach and avoidance behavior provide a means for assessing the rewarding or aversive value of stimuli, and can be quantified by a keypress procedure whereby subjects work to increase (approach, decrease (avoid, or do nothing about time of exposure to a rewarding/aversive stimulus. To investigate whether approach/avoidance behavior might be governed by quantitative principles that meet engineering criteria for lawfulness and that encode known features of reward/aversion function, we evaluated whether keypress responses toward pictures with potential motivational value produced any regular patterns, such as a trade-off between approach and avoidance, or recurrent lawful patterns as observed with prospect theory. METHODOLOGY/PRINCIPAL FINDINGS: Three sets of experiments employed this task with beautiful face images, a standardized set of affective photographs, and pictures of food during controlled states of hunger and satiety. An iterative modeling approach to data identified multiple law-like patterns, based on variables grounded in the individual. These patterns were consistent across stimulus types, robust to noise, describable by a simple power law, and scalable between individuals and groups. Patterns included: (i a preference trade-off counterbalancing approach and avoidance, (ii a value function linking preference intensity to uncertainty about preference, and (iii a saturation function linking preference intensity to its standard deviation, thereby setting limits to both. CONCLUSIONS/SIGNIFICANCE: These law-like patterns were compatible with critical features of prospect theory, the matching law, and alliesthesia. Furthermore, they appeared consistent with both mean-variance and expected utility approaches to the assessment of risk. Ordering of responses across categories of stimuli demonstrated three properties thought to be relevant for preference-based choice, suggesting these patterns might be grouped together as a

  12. A spatially explicit estimate of avoided forest loss.

    Science.gov (United States)

    Honey-Rosés, Jordi; Baylis, Kathy; Ramírez, M Isabel

    2011-10-01

    With the potential expansion of forest conservation programs spurred by climate-change agreements, there is a need to measure the extent to which such programs achieve their intended results. Conventional methods for evaluating conservation impact tend to be biased because they do not compare like areas or account for spatial relations. We assessed the effect of a conservation initiative that combined designation of protected areas with payments for environmental services to conserve over wintering habitat for the monarch butterfly (Danaus plexippus) in Mexico. To do so, we used a spatial-matching estimator that matches covariates among polygons and their neighbors. We measured avoided forest loss (avoided disturbance and deforestation) by comparing forest cover on protected and unprotected lands that were similar in terms of accessibility, governance, and forest type. Whereas conventional estimates of avoided forest loss suggest that conservation initiatives did not protect forest cover, we found evidence that the conservation measures are preserving forest cover. We found that the conservation measures protected between 200 ha and 710 ha (3-16%) of forest that is high-quality habitat for monarch butterflies, but had a smaller effect on total forest cover, preserving between 0 ha and 200 ha (0-2.5%) of forest with canopy cover >70%. We suggest that future estimates of avoided forest loss be analyzed spatially to account for how forest loss occurs across the landscape. Given the forthcoming demand from donors and carbon financiers for estimates of avoided forest loss, we anticipate our methods and results will contribute to future studies that estimate the outcome of conservation efforts. PMID:21902720

  13. Dynamics of the shade-avoidance response in Arabidopsis.

    Science.gov (United States)

    Ciolfi, Andrea; Sessa, Giovanna; Sassi, Massimiliano; Possenti, Marco; Salvucci, Samanta; Carabelli, Monica; Morelli, Giorgio; Ruberti, Ida

    2013-09-01

    Shade-intolerant plants perceive the reduction in the ratio of red light (R) to far-red light (FR) as a warning of competition with neighboring vegetation and display a suite of developmental responses known as shade avoidance. In recent years, major progress has been made in understanding the molecular mechanisms underlying shade avoidance. Despite this, little is known about the dynamics of this response and the cascade of molecular events leading to plant adaptation to a low-R/FR environment. By combining genome-wide expression profiling and computational analyses, we show highly significant overlap between shade avoidance and deetiolation transcript profiles in Arabidopsis (Arabidopsis thaliana). The direction of the response was dissimilar at the early stages of shade avoidance and congruent at the late ones. This latter regulation requires LONG HYPOCOTYL IN FAR RED1/SLENDER IN CANOPY SHADE1 and phytochrome A, which function largely independently to negatively control shade avoidance. Gene network analysis highlights a subnetwork containing ELONGATED HYPOCOTYL5 (HY5), a master regulator of deetiolation, in the wild type and not in phytochrome A mutant upon prolonged low R/FR. Network analysis also highlights a direct connection between HY5 and HY5 HOMOLOG (HYH), a gene functionally implicated in the inhibition of hypocotyl elongation and known to be a direct target of the HY5 transcription factor. Kinetics analysis show that the HYH gene is indeed late induced by low R/FR and that its up-regulation depends on the action of HY5, since it does not occur in hy5 mutant. Therefore, we propose that one way plants adapt to a low-R/FR environment is by enhancing HY5 function. PMID:23893169

  14. Sexual selection as a consequence of pathogen avoidance behaviors

    Energy Technology Data Exchange (ETDEWEB)

    Loehle, C. [Argonne National Lab., IL (United States); Logofet, D.O. [Russian Academy of Sciences, Moscow (Russian Federation). Laboratory of Mathematical Ecology

    1997-08-01

    The current theory that sexual selection results from female choice for good genes suffers from several problems. An alternative explanation is proposed. The pathogen avoidance hypothesis argues that the primary function of showy traits is to provide a reliable signal of current disease status so that sick individuals may be avoided during mating. Our studies shown that a significant risk of pathogen transmission occurs during mating and that showy traits are reliable indicators of current disease status. The origin of female choosiness is argued to lie in a general tendency to avoid sick individuals, even in the absence of showy traits. The showy traits are argued to originate as simple exaggerations of normal traits that are indicative of good health (bright feathers; vigorous movement; large size). Thus the origins of both showy traits and female choosiness are not problematic in this theory. A game theory analysis is employed to formalize the theory. Results of the game theory model support the theory. In particular, when the possession of male showy traits does not help reduce disease in the female, then showy traits are unlikely to occur. This case corresponds to the situation in large flocks or herds in which every animal is thoroughly exposed to all group pathogens on average. Such species do not exhibit showy traits. The good genes model does not make this prediction. The pathogen avoidance model can also lead to the evolution of showy traits even when selection is not effective against a given pathogen (e.g., when there is no heritable variation for resistance) but will lead to selection for resistance if such genes are present. Overall, the pathogen avoidance hypothesis provides a complete alternative to the good genes theory.

  15. 78 FR 28780 - Defense Federal Acquisition Regulation Supplement: Detection and Avoidance of Counterfeit...

    Science.gov (United States)

    2013-05-16

    ... Federal Acquisition Regulation Supplement: Detection and Avoidance of Counterfeit Electronic Parts (DFARS... detection and avoidance of counterfeit electronic parts. DATES: Comment Date: Comments on the proposed rule...-81, enacted December 31, 2011). Section 818 is entitled ``Detection and Avoidance of...

  16. Sex-specific positive and negative consequences of avoidance training during childhood on adult active avoidance learning in mice

    Directory of Open Access Journals (Sweden)

    Almuth Spröwitz

    2013-10-01

    The experiments revealed a clear sex difference in the group of late-adolescent mice: female mice showed better avoidance learning during late adolescence compared to males, and the beneficial impact of late-adolescent pretraining on adult learning was more pronounced in females compared to males.

  17. Fear-avoidance beliefs and pain avoidance in low back pain--translating research into clinical practice

    DEFF Research Database (Denmark)

    Rainville, James; Smeets, Rob J E M; Bendix, Tom; Tveito, Torill H; Poiraudeau, Serge; Indahl, Aage J

    2011-01-01

    For patients with low back pain, fear-avoidance beliefs (FABs) represent cognitions and emotions that underpin concerns and fears about the potential for physical activities to produce pain and further harm to the spine. Excessive FABs result in heightened disability and are an obstacle for...... recovery from acute, subacute, and chronic low back pain....

  18. Integrating Collision Avoidance, Lane Keeping, and Cruise Control With an Optimal Controller and Fuzzy Controller

    OpenAIRE

    Grefe, William Kevin

    2005-01-01

    This thesis presents collision avoidance integrated with lane keeping and adaptive cruise control for a car. Collision avoidance is the ability to avoid obstacles that are in the vehicleâ s path, without causing damage to the obstacle or car. There are three types of collision avoidance controllers, passive, active, and semi-active. This thesis is designed using active collision avoidance controllers. There are two controllers developed for collision avoidance in this paper. They are ...

  19. DAIDALUS: Detect and Avoid Alerting Logic for Unmanned Systems

    Science.gov (United States)

    Munoz, Cesar; Narkawicz, Anthony; Consiglio, Maria; Chamberlain, James; Hagen, George; Upchurch, Jason; Dutle, Aaron

    2015-01-01

    This paper presents DAIDALUS (Detect and Avoid Alerting Logic for Unmanned Systems), a reference implementation of a detect and avoid concept intended to support the integration of Unmanned Aircraft Systems into civil airspace. DAIDALUS consists of self-separation and alerting algorithms that provide situational awareness to UAS remote pilots. These algorithms have been formally specified in a mathematical notation and verified for correctness in an interactive theorem prover. The software implementation has been verified against the formal models and validated against multiple stressing cases jointly developed by the US Air Force Research Laboratory, MIT Lincoln Laboratory, and NASA. The DAIDALUS reference implementation is currently under consideration for inclusion in the appendices to the Minimum Operational Performance Standards for Unmanned Aircraft Systems presently being developed by RTCA Special Committee 228.

  20. Measuring the Willingness to Pay to Avoid Guilt

    DEFF Research Database (Denmark)

    Bellemare, Charles; Sebald, Alexander Christopher; Strobel, Martin

    We estimate structural models of guilt aversion to measure the population level of willingness to pay (WTP) to avoid feeling guilt by letting down another player. We compare estimates of WTP under the assumption that higher-order beliefs are in equilibrium (i.e. consistent with the choice distrib...... is substantially overestimated (by a factor of two) when correlation between preferences and beliefs is not controlled for. Finally, we find no evidence that WTP is significantly related to the observable socio-economic characteristics of players....... experiment of proposal and response conducted with a large and representative sample of the Dutch population. Our range of estimates suggests that responders are willing to pay between 0.40 and 0.80 Euro to avoid letting down proposers by 1 Euro. Furthermore, we find that WTP estimated using stated beliefs...

  1. Measuring the willingness to pay to avoid guilt

    DEFF Research Database (Denmark)

    Bellemare, Charles; Sebald, Alexander Christopher; Strobel, Martin

    2011-01-01

    We estimate structural models of guilt aversion to measure the population level of willingness to pay (WTP) to avoid feeling guilt by letting down another player. We compare estimates of WTP under the assumption that higher-order beliefs are in equilibrium (i.e., consistent with the choice distri...... substantially overestimated (by a factor of two) when correlation between preferences and beliefs is not controlled for. Finally, we find no evidence that WTP is significantly related to the observable socio-economic characteristics of players....... experiment of proposal and response conducted with a large and representative sample of the Dutch population. Our range of estimates suggests that responders are willing to pay between ¤0.40 and ¤0.80 to avoid letting down proposers by ¤1. Furthermore, we find that WTP estimated using stated beliefs is...

  2. Airborne Collision Avoidance System as a Cyber-Physical System

    Directory of Open Access Journals (Sweden)

    Andrei C. NAE

    2015-12-01

    Full Text Available In this paper the key concepts of ITS - Intelligent Transport Systems, CPS - Cyber-Physical Systems and SM - Smart Mobility are defined and correlated with the need for ACAS – Airborne Collision Avoidance System, as the last resort safety net and indispensable ingredient in civil aviation. Smart Mobility is addressed from a Cyber Physical-Systems perspective, detailing some of the elements that this entails. Here we consider the Air Transportations System of the future as a Cyber-Physical System and analyze the implications of doing so from different perspectives. The objective is to introduce a 4D collision avoidance shield technology which forms a last resort safety net technology for the next generation air transport (2050 and beyond. The new system will represent a step change over the performance of current technology. As conclusions, the benefits of implementing Transport Cyber-Physical Systems are discussed, as well as what this would require for future deployment.

  3. Avoiding climate change uncertainties in Strategic Environmental Assessment

    DEFF Research Database (Denmark)

    Larsen, Sanne Vammen; Kørnøv, Lone; Driscoll, Patrick Arthur

    2013-01-01

    This article is concerned with how Strategic Environmental Assessment (SEA) practice handles climate change uncertainties within the Danish planning system. First, a hypothetical model is set up for how uncertainty is handled and not handled in decision-making. The model incorporates the strategies...... ‘reduction’ and ‘resilience’, ‘denying’, ‘ignoring’ and ‘postponing’. Second, 151 Danish SEAs are analysed with a focus on the extent to which climate change uncertainties are acknowledged and presented, and the empirical findings are discussed in relation to the model. The findings indicate that despite...... incentives to do so, climate change uncertainties were systematically avoided or downplayed in all but 5 of the 151 SEAs that were reviewed. Finally, two possible explanatory mechanisms are proposed to explain this: conflict avoidance and a need to quantify uncertainty....

  4. PRIORITY BASED CONGESTION DETECTION AND AVOIDANCE IN WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    R. Beulah Jayakumari

    2013-01-01

    Full Text Available The primary objective of event driven wireless sensor networks is to route the detected or monitored data at the earliest to the base station depending on their degree of priority since the data generated in a sensor network has different importance. In order to avoid indiscriminate dropping of data during congestion we propose a novel congestion protocol named priority based congestion detection and avoidance in wireless sensor networks. It aims to provide differentiated data delivery during congestion which comprises of packet priority assignment based on data value, dual queue scheduler for scheduling the next packet to forward based on priority and finally a dynamic dual path congestion aware routing protocol is developed. Our simulation results and analysis shows that this new protocol provides better performance than existing protocols in terms of throughput, packet delivery ratio and packet loss.

  5. Robotic Path Finding with Collision Avoidance Using Expert System

    Institute of Scientific and Technical Information of China (English)

    蔡自兴

    1989-01-01

    A rule-based expert system has been developed and used into a robotic planning system with collision-avoidance,The world model is represented as the knowledge data and stored in the knowledge base with rules.The expert system can find a collision-avoidance path.Otherwise.it shows the collision secton in which the moved object is blocked,Several examples for the different objects to pass through the different channels and to find a collision-free path have been tested.The simulating results of the palnner give out the planning sequence or blocked section(s).The output information is useful for making decision of the robot motion and modifyting the technological parameters of the world.

  6. Robotic Path Finding with Collision Avoidance Using Expert System

    Institute of Scientific and Technical Information of China (English)

    蔡自兴

    1989-01-01

    A rule-based expert system has been developed and used into a robotic planning system with collision-avoidance, The world model is represented as the knowledge data and stored in the knowledge base with rules. The expert system can find a collision-avoidance path . Otherwise, it shows the collision secton in which the moved object is blocked . Several examples for the different objects to pass throngli the different channels and to find a collision-free path have been testnd. The simulating resuks of the planner give out the planning sequence or blocked section(s) . The output information is useful for making decision of the robot motion and modifying the technological parameters of the world .

  7. Target Tracking and Obstacle Avoidance for Multi-agent Systems

    Institute of Scientific and Technical Information of China (English)

    Jing Yan; Xin-Ping Guan; Fu-Xiao Tan

    2010-01-01

    This paper considers the problems of target tracking and obstacle avoidance for multi-agent systems.To solve the problem that multiple agents cannot effectively track the target while avoiding obstacle in dynamic environment,a novel control algorithm based on potential function and behavior rules is proposed.Meanwhile,the interactions among agents are also considered.According to the state whether an agent is within the area of its neighbors' influence,two kinds of potential functions are presented.Meanwhile,the distributed control input of each agent is determined by relative velocities as well as relative positions among agents,target and obstacle.The maximum linear speed of the agents is also discussed.Finally,simulation studies are given to demonstrate the performance of the proposed algorithm.

  8. Scaling of the atmosphere of self-avoiding walks

    Energy Technology Data Exchange (ETDEWEB)

    Owczarek, A L [Department of Mathematics and Statistics, The University of Melbourne, Victoria 3010 (Australia); Prellberg, T [School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)], E-mail: a.owczarek@ms.unimelb.edu.au, E-mail: t.prellberg@qmul.ac.uk

    2008-09-19

    The number of free sites next to the end of a self-avoiding walk is known as the atmosphere of the walk. The average atmosphere can be related to the number of configurations. Here we study the distribution of atmospheres as a function of length and how the number of walks of fixed atmosphere scale. Certain bounds on these numbers can be proved. We use Monte Carlo estimates to verify our conjectures in two dimensions. Of particular interest are walks that have zero atmosphere, which are known as trapped. We demonstrate that these walks scale in the same way as the full set of self-avoiding walks, barring an overall constant factor.

  9. Compressed self-avoiding walks, bridges and polygons

    Science.gov (United States)

    Beaton, Nicholas R.; Guttmann, Anthony J.; Jensen, Iwan; Lawler, Gregory F.

    2015-11-01

    We study various self-avoiding walks (SAWs) which are constrained to lie in the upper half-plane and are subjected to a compressive force. This force is applied to the vertex or vertices of the walk located at the maximum distance above the boundary of the half-space. In the case of bridges, this is the unique end-point. In the case of SAWs or self-avoiding polygons, this corresponds to all vertices of maximal height. We first use the conjectured relation with the Schramm-Loewner evolution to predict the form of the partition function including the values of the exponents, and then we use series analysis to test these predictions. Dedicated to R J Baxter, for his 75th birthday.

  10. Enumeration of self-avoiding walks on the square lattice

    International Nuclear Information System (INIS)

    We describe a new algorithm for the enumeration of self-avoiding walks on the square lattice. Using up to 128 processors on a HP Alpha server cluster we have enumerated the number of self-avoiding walks on the square lattice to length 71. Series for the metric properties of mean-square end-to-end distance, mean-square radius of gyration and mean-square distance of monomers from the end points have been derived to length 59. An analysis of the resulting series yields accurate estimates of the critical exponents γ and ν confirming predictions of their exact values. Likewise we obtain accurate amplitude estimates yielding precise values for certain universal amplitude combinations. Finally we report on an analysis giving compelling evidence that the leading non-analytic correction-to-scaling exponent Δ1 = 3/2

  11. Compressed self-avoiding walks, bridges and polygons

    International Nuclear Information System (INIS)

    We study various self-avoiding walks (SAWs) which are constrained to lie in the upper half-plane and are subjected to a compressive force. This force is applied to the vertex or vertices of the walk located at the maximum distance above the boundary of the half-space. In the case of bridges, this is the unique end-point. In the case of SAWs or self-avoiding polygons, this corresponds to all vertices of maximal height. We first use the conjectured relation with the Schramm–Loewner evolution to predict the form of the partition function including the values of the exponents, and then we use series analysis to test these predictions. (paper)

  12. Structural characterization of ice polymorphs from self-avoiding walks

    Science.gov (United States)

    Herrero, Carlos P.

    2014-08-01

    Topological properties of crystalline ice structures are studied by means of self-avoiding walks on their H-bond networks. The number of self-avoiding walks, Cn, for eight ice polymorphs has been obtained by direct enumeration up to walk length n=27. This has allowed us to determine the ‘connective constant' or effective coordination number μ of these structures as the limit of the ratio Cn/Cn-1 for large n. This structure-dependent parameter μ is related with other topological characteristics of ice polymorphs, such as the mean and minimum ring size, or the topological density of network sites. A correlation between the connective constant and the configurational entropy of hydrogen-disordered ice structures is discussed.

  13. Scaling of the atmosphere of self-avoiding walks

    International Nuclear Information System (INIS)

    The number of free sites next to the end of a self-avoiding walk is known as the atmosphere of the walk. The average atmosphere can be related to the number of configurations. Here we study the distribution of atmospheres as a function of length and how the number of walks of fixed atmosphere scale. Certain bounds on these numbers can be proved. We use Monte Carlo estimates to verify our conjectures in two dimensions. Of particular interest are walks that have zero atmosphere, which are known as trapped. We demonstrate that these walks scale in the same way as the full set of self-avoiding walks, barring an overall constant factor

  14. Real-Time Fuzzy Obstacle Avoidance Using Directional Visual Perception

    Institute of Scientific and Technical Information of China (English)

    Huang Guoquan(黄国权); Rad A. B.; Wong Y. K.

    2004-01-01

    This paper presents a novel vision-based obstacle avoidance approach for the Autonomous Mobile Robot (AMR) with a Pan- Tilt-Zoom (PTZ) camera as its only sensing modality. The approach combines the morphological closing operation based on Sobel Edge Detection Operation and the (μ-kσ) thresholding technique to detect obstacles to soften the various lighting and ground floor effects. Both the morphology method and thresholding technique are computationally simple. The processing speed of the algorithm is fast enough to avoid some active obstacles. In addition, this approach takes into account the history obstacle effects on the current state. Fuzzy logic is used to control the behaviors of AMR as it navigates in the environment. All behaviors run concurrently and generate motor response solely based on vision perception. A priority based on subsumption coordinator selects the most appropriate response to direct the AMR away from obstacles. Validation of the proposed approach is done on a Pioneer 1 mobile robot.

  15. Difficulties in avoiding exposure to allergens in cosmetics

    DEFF Research Database (Denmark)

    Larsen, Kristian

    2007-01-01

    The aim of the study is to describe the ability of patients with allergic contact dermatitis to avoid exposure to allergens in cosmetics. The study is a questionnaire survey among 382 patients with contact allergy to preservatives and fragrances, included from 3 dermatological clinics. The...... questionnaire included questions about the level of difficulty in reading labels of ingredients on cosmetics and about patients' strategies to avoid substances they were allergic to. It also included questions about eczema severity as well as about educational level. 46% of the patients found it difficult or...... extremely difficult to read the ingredient labelling of cosmetics, and this finding was significantly related to low educational level. Patients allergic to formaldehyde and methyldibromo glutaronitrile experienced the worst difficulties, while patients with fragrance allergy found ingredient label reading...

  16. Departures from optimality when pursuing multiple approach or avoidance goals.

    Science.gov (United States)

    Ballard, Timothy; Yeo, Gillian; Neal, Andrew; Farrell, Simon

    2016-07-01

    This article examines how people depart from optimality during multiple-goal pursuit. The authors operationalized optimality using dynamic programming, which is a mathematical model used to calculate expected value in multistage decisions. Drawing on prospect theory, they predicted that people are risk-averse when pursuing approach goals and are therefore more likely to prioritize the goal in the best position than the dynamic programming model suggests is optimal. The authors predicted that people are risk-seeking when pursuing avoidance goals and are therefore more likely to prioritize the goal in the worst position than is optimal. These predictions were supported by results from an experimental paradigm in which participants made a series of prioritization decisions while pursuing either 2 approach or 2 avoidance goals. This research demonstrates the usefulness of using decision-making theories and normative models to understand multiple-goal pursuit. (PsycINFO Database Record PMID:26963081

  17. Self-Avoiding Random Dynamics on Integer Complex Systems

    CERN Document Server

    Hamze, Firas; de Freitas, Nando

    2011-01-01

    This paper introduces a new specialized algorithm for equilibrium Monte Carlo sampling of binary-valued systems, which allows for large moves in the state space. This is achieved by constructing self-avoiding walks (SAWs) in the state space. As a consequence, many bits are flipped in a single MCMC step. We name the algorithm SARDONICS, an acronym for Self-Avoiding Random Dynamics on Integer Complex Systems. The algorithm has several free parameters, but we show that Bayesian optimization can be used to automatically tune them. SARDONICS performs remarkably well in a broad number of sampling tasks: toroidal ferromagnetic and frustrated Ising models, 3D Ising models, restricted Boltzmann machines and chimera graphs arising in the design of quantum computers.

  18. Complication avoidance and its management in endoscopic neurosurgery

    Directory of Open Access Journals (Sweden)

    Yad Ram Yadav

    2013-01-01

    Full Text Available Endoscopic techniques are increasingly being used in recent times for various spinal and brain pathologies. Although endoscopic neurosurgical technique holds the potential for reducing morbidity, it is also associated with limitations such as steep learning curve, obstruction in manipulation of instruments by telescope in an already limited exposure, proximal blind spot, visual obscuration, disorientation, loss of stereoscopic image and others. Neuroendoscopy is distinct from micro-surgery and a thorough understanding of the technique and its limitations is required to get maximal benefit. Difficulties in controlling bleeding, longer operative time are common obstacles with this technique, especially in early learning curve. Higher complication rate during initial learning curve can be reduced by attending live workshops, practice on models and hands on cadaveric workshops. Large vascular lesions should be avoided and a thorough knowledge of possible complications and techniques to avoid such complications can improve results in endoscopic surgery.

  19. Avoiding climate change uncertainties in Strategic Environmental Assessment

    International Nuclear Information System (INIS)

    This article is concerned with how Strategic Environmental Assessment (SEA) practice handles climate change uncertainties within the Danish planning system. First, a hypothetical model is set up for how uncertainty is handled and not handled in decision-making. The model incorporates the strategies ‘reduction’ and ‘resilience’, ‘denying’, ‘ignoring’ and ‘postponing’. Second, 151 Danish SEAs are analysed with a focus on the extent to which climate change uncertainties are acknowledged and presented, and the empirical findings are discussed in relation to the model. The findings indicate that despite incentives to do so, climate change uncertainties were systematically avoided or downplayed in all but 5 of the 151 SEAs that were reviewed. Finally, two possible explanatory mechanisms are proposed to explain this: conflict avoidance and a need to quantify uncertainty

  20. Avoidance within a changing assessment paradigm for Mediterranean Hake stocks

    Directory of Open Access Journals (Sweden)

    S. RAGONESE

    2012-12-01

    Full Text Available The Mediterranean hake Merluccius merluccius L., 1758, is the emblem of the so-called Mediterranean demersal fisheries paradox, showing a persistent, although stable, status of growth overexploitation and an impressive gap between current and any biological reference point. Almost full avoidance capability of large size females to bottom trawls, higher overall growth rates than previously believed and higher natural mortality in juveniles than adult, were considered among the most plausible explanation factors of such persistence. In the present note, arguments are illustrated to raise some concern about avoidance and highlight the important role of the other factors in improving assessments and launching a short term recovery plan for Mediterranean Hake stocks which is more acceptable to fishermen.

  1. [Big data, Roemer's law and avoidable hospital admissions].

    Science.gov (United States)

    van der Horst, H E

    2016-01-01

    From an analysis of data from 23 European countries to determine the impact of primary care on avoidable hospital admissions for uncontrolled diabetes it appeared that, contrary to expectation, countries with strong primary care did not have a lower rate of avoidable hospital admission. It is clear that Roemer's law, 'a bed built is a bed filled,' still applies. However, the validity of this sort of analysis can be questioned, as these data are highly aggregated, and registration quality differs between countries. It is also questionable if these datasets can be considered as 'big data' as there are relatively small numbers per country. Big data analyses are useful for discerning patterns and formulating hypotheses, but not for proving causality. An unwanted side effect of this kind of analysis might be that policymakers use these not so valid results to underpin their policy to their advantage. PMID:27484429

  2. Structural characterization of ice polymorphs from self-avoiding walks

    CERN Document Server

    Herrero, Carlos P

    2014-01-01

    Topological properties of crystalline ice structures are studied by means of self-avoiding walks on their H-bond networks. The number of self-avoiding walks, C_n, for eight ice polymorphs has been obtained by direct enumeration up to walk length n = 27. This has allowed us to determine the `connective constant' or effective coordination number `mu' of these structures as the limit of the ratio C_n/C_{n-1} for large n. This structure-dependent parameter `mu' is related with other topological characteristics of ice polymorphs, such as the mean and minimum ring size, or the topological density of network sites. A correlation between the connective constant and the configurational entropy of hydrogen-disordered ice structures is discussed.

  3. Line-bisectioning and obstacle avoidance: evidence for separate strategies.

    Science.gov (United States)

    Ross, Alasdair I; Schenk, Thomas; Hesse, Constanze

    2014-09-01

    Previous studies have frequently applied a combination of line-bisection tasks (in which participants indicate the middle of a line) and obstacle avoidance tasks (in which participants move their hand between two obstacles) with the aim of revealing perception-action dissociations in certain neurological disorders, such as visual form agnosia and optic ataxia. However, valid conclusions about the underlying processing pathways can only be drawn if participants apply the same strategy in both tasks (i.e. finding the middle between the obstacles). Yet, this assumption has never been tested directly. In this experiment, we investigated whether participants perform obstacle avoidance and line-bisectioning using similar strategies by manipulating the position of the obstacles and the start position of the hand relative to the obstacles. Our results indicate that the lateral hand position during obstacle avoidance does not only vary as a function of obstacle location but also strongly depends on the start position. Moreover, participants showed increased sensitivity to obstacle shifts occurring closer to the hand's start position. In contrast, during line-bisectioning the sensitivity to obstacles shifts was unaffected by the hand's start position. The findings suggest that during obstacle-avoidance the need to keep a safe distance from the obstacles is balanced with the requirement to minimise energetic demands. In contrast, the main intention during line-bisectioning is to move to the perceived midpoint as accurately as possible. The fact that very different constraints underlie trajectory planning in both tasks implies that caution has to be taken when interpreting differences in performance levels. PMID:24951918

  4. Avoidance motivation and choking under pressure in soccer penalty shootouts

    OpenAIRE

    Jordet, Geir; Hartman, Esther

    2008-01-01

    The purpose of this study was to examine the relationships between shot valence, avoidance behavior, and performance in soccer penalty shootouts. Video analyses were conducted with all penalty shootouts ever held in the World Cup, the European Championships, and the UEFA Champions League (n = 36 shootouts, 359 kicks). Shot valence was assessed from the potential consequences of a shot outcome as follows: Shots where a goal instantly leads to victory were classified as positive valence shots a...

  5. A Study of MMW Collision Avoidance Radar System for Trains

    OpenAIRE

    Liu Hai-bo; Sheng Meng-meng; Yang Xiao-qian

    2013-01-01

    Collision avoidance radar for trains is pregnant for safety transportation. In order to realize low cost and high performance of azimuth accuracy, we have developed MMW (Milli-Meter Wave) radar, which employs switched phased array and frequency stepped technology. This paper analyses the radiation patterns of transmitting/receiving antennas and compensation method for amplitude/phase errors of synthetic wideband frequency stepped signal. To confirm the operation of the radar, low cost millime...

  6. Platform Siphoning: Ad-Avoidance and Media Content

    OpenAIRE

    Simon P. Anderson; Joshua S. Gans

    2011-01-01

    Content providers rely on advertisers to pay for content. TiVo, remote controls, and pop-up ad blockers are examples of ad-avoidance technologies that allow consumers to view content without ads, and thereby siphon off the content without paying the "price." We examine the content provider's reaction to such technologies, demonstrating that their adoption increases advertising clutter (leading to a potential downward spiral), may reduce total welfare and content quality, and can lead to more ...

  7. Procrastination and counterfactual thinking: avoiding what might have been.

    OpenAIRE

    Sirois, F.M.

    2004-01-01

    The possible negative consequences of counterfactuals were explored in the current study by examining the relationship between counterfactual direction and trait procrastination, a self-defeating behavioural style. Eighty participants generated counterfactuals in response to two experimental anxiety inductions. Trait procrastination was overall related to avoiding thoughts about how things could have been better (making more downward and relatively fewer upward counterfactuals) in response to...

  8. Rumination, experiential avoidance, and dysfunctional thinking in eating disorders

    OpenAIRE

    Rawal, A.; Park, R J; Williams, J.M.G.

    2010-01-01

    The majority of research in eating disorders (ED) has investigated the content of disorder-specific thoughts, while few studies have addressed underlying cognitive-affective processes. A better understanding of processes underpinning ED may have important implications for treatment development. Two studies were conducted that investigated levels of rumination, beliefs about rumination, experiential avoidance, and aspects of schematic thinking in individuals with eating pathology. The latter w...

  9. Approach-Avoidance Behavior of Refugees in a Finnish School

    OpenAIRE

    Laasonen, Ed.D. Raimo J

    1991-01-01

    The purpose of the study was to research how the Vietnamese refugees (N was 9) behave with a Finnish school environment. Participating observation was applied because of the lack of public possibilities to study the phenomenon openly. The Markovian approach was the analysis of the data. The results indicate school environment, its interaction guides how the refugees behave in their approach-avoidance behavior. Principally, the behavior of the surrounding school environment p...

  10. Recognition of Threshold Dose Model: Avoiding Continued Excessive Regulation

    International Nuclear Information System (INIS)

    The purpose of this work is to examine the relationships between radiation dose-response models and associated regulations. It is concluded that recognition of the validity of a threshold model can be done on the basis of presently known data and that changes in regulations should be started at this time to avoid further unnecessary losses due to continued excessive regulation. As results from new research come in, refinement of interim values proposed in revised regulations can be incorporated

  11. Asymmetric learning to avoid heterospecific males in Mesocricetus hamsters

    OpenAIRE

    delBarco-Trillo, Javier; Johnston, Robert E.

    2012-01-01

    If a female mates with a male of a closely related species, her fitness is likely to decline. Consequently, females may develop behavioral mechanisms to avoid mating with heterospecific males. In some species, one such mechanism is for adult females to learn to discriminate against heterospecific males after exposure to such males. We have previously shown that adult, female Syrian hamsters (Mesocricetus auratus) learn to discriminate against male Turkish hamsters (Mesocricetus brandti) after...

  12. The pathogen transmission avoidance theory of sexual selection

    Energy Technology Data Exchange (ETDEWEB)

    Loehle, C.

    1997-08-01

    The current theory that sexual selection results from female preference for males with good genes suffers from several problems. An alternative explanation, the pathogen transmission avoidance hypothesis, argues that the primary function of showy traits is to provide a reliable signal of current disease status, so that sick individuals can be avoided during mating. This study shows that a significant risk of pathogen transmission occurs during mating and that showy traits are reliable indicators of current disease status. The origin of female choosiness is argued to lie in a general tendency to avoid sick individuals, even in the absence of showy traits, which originate as exaggerations of normal traits that are indicative of good health (bright feathers, vigorous movement, large size). Thus, in this new model the origins of both showy traits and female choosiness are not problematic and there is no threshold effect. This model predicts that when the possession of male showy traits does not help to reduce disease in the female, showy traits are unlikely to occur. This case corresponds to thorough exposure of every animal to all group pathogens, on average, in large groups. Such species are shown with a large data set on birds to be less likely to exhibit showy traits. The good-genes model does not make this prediction. The pathogen transmission avoidance model can also lead to the evolution of showy traits even when selection is not effective against a given pathogen (e.g., when there is no heritable variation for resistance), but can result in selection for resistance if such genes are present. Monogamy is argued to reduce selection pressures for showy traits; data show monogamous species to be both less parasitized and less showy. In the context of reduction of pathogen transmission rates in showy populations, selection pressure becomes inversely frequency-dependent, which makes showy traits likely to be self-limiting rather than runaway.

  13. Self-help Books on Avoiding Time Shortage

    OpenAIRE

    Larsson, Jörgen; Sanne, Christer

    2005-01-01

    Abstract Self-help books are tokens of our reflexive individualized society. The widespread experience of too high a pace in daily life and too little time for recovery and for social relations have resulted in books focusing on avoiding time shortage. In our analysis of the advice in such books we found time-management categories such as streamlining activities and buying services. Other identified categor...

  14. Obstacle avoidance for mobile robots using lidar sensors

    OpenAIRE

    Rodríguez Rosales, Juan Esteban

    2011-01-01

    This master thesis is aimed at developing a ROS compatible obstacle avoidance module for a Segway RMP400 platform using lidar sensors. The algorithm implemented supports different 3D scenarios, such as slopes and precipices. Given that the currently available navigation modules in the ROS stack work only for 2D, significant modification of the navigation stack was mandatory. The proposed solution does not take into account the non-holonomic constraints of the platform. An alter...

  15. Optimal self-avoiding paths in dilute random medium

    OpenAIRE

    Seno, F.; Stella, A.L.; Vanderzande, C.

    1995-01-01

    By a new type of finite size scaling analysis on the square lattice, and by renormalization group calculations on hierarchical lattices we investigate the effects of dilution on optimal undirected self-avoiding paths in a random environment. The behaviour of the optimal paths remains the same as for directed paths in undiluted medium, as long as forbidden bonds are not exceeding the percolation threshold. Thus, overhanging configurations do not alter the standard self-affine directed polymer ...

  16. An Analytical Approach to Avoid Obstacles in Mobile Robot Navigation

    OpenAIRE

    Alexandre Santos Brandão; Mário Sarcinelli-Filho; Ricardo Carelli

    2013-01-01

    A nonlinear supervised globally stable controller is proposed to reactively guide a mobile robot to avoid obstacles while seeking a goal. Whenever the robot detects an object nearby, its orientation is changed to be aligned with the tangent to the border of the obstacle. Then, the robot starts following it, looking for a feasible path to its goal. The supervisor is responsible for deciding which path to take when the robot faces some particular obstacle configurations that are quite difficult...

  17. Variable-interval schedules of timeout from avoidance

    OpenAIRE

    Perone, Michael; Galizio, Mark

    1987-01-01

    Rats were trained on concurrent schedules in which pressing one lever postponed shock and pressing the other occasionally produced a 2-min timeout during which the shock-postponement schedule was suspended and its correlated stimuli were removed. Throughout, the shock-postponement schedule maintained proficient levels of avoidance. Nevertheless, in Experiment 1 responding on the timeout lever was established rapidly, was maintained at stable levels on variable-interval schedules, was extingui...

  18. Dopamine Regulates Approach-Avoidance in Human Sensation-Seeking

    OpenAIRE

    Norbury, A.; Kurth-Nelson, Z.; Winston, J. S.; Roiser, J.P.; M. Husain

    2015-01-01

    Background: Sensation-seeking is a trait that constitutes an important vulnerability factor for a variety of psychopathologies with high social cost. However, little is understood either about the mechanisms underlying motivation for intense sensory experiences or their neuropharmacological modulation in humans. Methods: Here, we first evaluate a novel paradigm to investigate sensation-seeking in humans. This test probes the extent to which participants choose either to avoid or self-administ...

  19. Factors associated with healthcare avoidance among transgender women in Argentina

    OpenAIRE

    Socías, María Eugenia; Marshall, Brandon DL; Arístegui, Inés; Romero, Marcela; Cahn, Pedro; Kerr, Thomas; Sued, Omar

    2014-01-01

    Introduction Transgender (TG) women in many settings continue to contend with barriers to healthcare, including experiences of stigma and discrimination. Argentina has a universal health care system and laws designed to promote healthcare access among TG women. However, little is known about barriers to healthcare access among TG women in this setting. The aim of this study was to explore individual, social-structural and environmental factors associated with healthcare avoidance among TG wom...

  20. A new method to avoid PPP in data evaluation

    Institute of Scientific and Technical Information of China (English)

    Chen Zhen-Peng; Sun Ye-Ying

    2004-01-01

    The Peelle Pertinent Puzzle (PPP) has been studied systematically. The results obtained by using several proposed methods to deal with a sample of 6Li(n, t) are compared with each other. The cause of PPP occurrence has been found.error according to the relative extent of discrepancy'. The method is able to produce the best result and should be used to avoid the PPP at first.

  1. Obstacle Avoidance in Groping Locomotion of a Humanoid Robot

    OpenAIRE

    Masahiro Ohka; Kazuhisa Mitobe; Yasuo Nasu; Mitsuhiro Yamano; Hanafiah Yussof

    2005-01-01

    This paper describes the development of an autonomous obstacle-avoidance method that operates in conjunction with groping locomotion on the humanoid robot Bonten-Maru II. Present studies on groping locomotion consist of basic research in which humanoid robot recognizes its surroundings by touching and groping with its arm on the flat surface of a wall. The robot responds to the surroundings by performing corrections to its orientation and locomotion direction. During groping locomotion, howev...

  2. Continuous time `true' self-avoiding random walk on Z

    CERN Document Server

    Toth, Balint

    2009-01-01

    We consider the continuous time version of the `true' or `myopic' self-avoiding random walk with site repulsion in 1d. The Ray-Knight-type method which was applied to the discrete time and edge repulsion case, is applicable to this model with some modifications. We present a limit theorem for the local time of the walk and a local limit theorem for the displacement.

  3. Self-avoiding walks subject to a force

    Science.gov (United States)

    Janse van Rensburg, E. J.; Whittington, S. G.

    2016-03-01

    We prove some theorems about self-avoiding walks attached to an impenetrable surface (i.e. positive walks) and subject to a force. Specifically we show the force dependence of the free energy is identical when the force is applied at the last vertex or at the top (confining) plane. We discuss the relevance of this result to numerical results and to a recent result about convergence rates when the walk is being pushed towards the surface.

  4. Self-avoiding walks and polygons on quasiperiodic tilings

    OpenAIRE

    Rogers, A. N.; Richard, C.; Guttmann, A. J.

    2003-01-01

    We enumerate self-avoiding walks and polygons, counted by perimeter, on the quasiperiodic rhombic Penrose and Ammann-Beenker tilings, thereby considerably extending previous results. In contrast to similar problems on regular lattices, these numbers depend on the chosen start vertex. We compare different ways of counting and demonstrate that suitable averaging improves converge to the asymptotic regime. This leads to improved estimates for critical points and exponents, which support the conj...

  5. Multifractality of self-avoiding walks on percolation clusters

    OpenAIRE

    Blavatska, Viktoria; Janke, Wolfhard

    2008-01-01

    We consider self-avoiding walks (SAWs) on the backbone of percolation clusters in space dimensions d=2, 3, 4. Applying numerical simulations, we show that the whole multifractal spectrum of singularities emerges in exploring the peculiarities of the model. We obtain estimates for the set of critical exponents, that govern scaling laws of higher moments of the distribution of percolation cluster sites visited by SAWs, in a good correspondence with an appropriately summed field-theoretical \\var...

  6. Scaling behavior of self-avoiding walks on percolation clusters

    OpenAIRE

    Blavatska, Viktoria; Janke, Wolfhard

    2008-01-01

    The scaling behavior of self-avoiding walks (SAWs) on the backbone of percolation clusters in two, three and four dimensions is studied by Monte Carlo simulations. We apply the pruned-enriched Rosenbluth chain-growth method (PERM). Our numerical results bring about the estimates of critical exponents, governing the scaling laws of disorder averages of the end-to-end distance of SAW configurations. The effects of finite-size scaling are discussed as well.

  7. Self-avoiding walks subject to a force

    OpenAIRE

    van Rensburg, EJ Janse; Whittington, SG

    2015-01-01

    We prove some theorems about self-avoiding walks attached to an impenetrable surface (i.e. positive walks) and subject to a force. Specifically we show the force dependence of the free energy is identical when the force is applied at the last vertex or at the top (confining) plane. We discuss the relevance of this result to numerical results and to a recent result about convergence rates when the walk is being pushed towards the surface.

  8. Self-avoiding effective strings in lattice gauge theories

    CERN Document Server

    Caselle, M

    1992-01-01

    It is shown that the effective string recently introduced to describe the long distance dynamics of 3D gauge systems in the confining phase has an intriguing description in terms of models of 2D self-avoiding walks in the dense phase. The deconfinement point, where the effective string becomes N=2 supersymmetric, may then be interpreted as the tricritical Theta point where the polymer chain undergoes a collapse transition. As a consequence, a universal value of the deconfinement temperature is predicted.

  9. Continuously Varying Exponents for Oriented Self-Avoiding Walks

    OpenAIRE

    Cardy, John

    1993-01-01

    A two-dimensional conformal field theory with a conserved $U(1)$ current $\\vec J$, when perturbed by the operator ${\\vec J}^{\\,2}$, exhibits a line of fixed points along which the scaling dimensions of the operators with non-zero $U(1)$ charge vary continuously. This result is applied to the problem of oriented polymers (self-avoiding walks) in which the short-range repulsive interactions between two segments depend on their relative orientation. While the exponent $\

  10. Avoiding common problems during online submission of manuscripts.

    Science.gov (United States)

    Welch, Stephen J

    2007-05-01

    Online submission of manuscripts is normally fast, relatively easy, and timely. However, failure to follow journal instructions, omitting required aspects of manuscripts, and other problems can delay or stop the submission and peer-review process. This article discusses common problems encountered during online submission and advises authors on how to avoid those problems and maximize the efficiency of the online submission process. PMID:17494812

  11. Collision detection and avoidance system based on computer vision

    OpenAIRE

    Kalvå, Andreas

    2014-01-01

    A wide selection of stereo matching algorithms have been evaluated for the purpose ofcreating a collision avoidance module. Varying greatly in the accuracy, a few of thealgorithms were fast enough for further use.Two computer vision libraries, OpenCV and MRF, were evaluated for their implementationsof various stereo matching algorithms. In addition OpenCV provides a wide variety offunctions for creating sophisticated computer vision programs and were evaluated onthis basis as well.A stereo ca...

  12. Disgust: the disease-avoidance emotion and its dysfunctions

    OpenAIRE

    Davey, Graham C. L.

    2011-01-01

    This review analyses the accumulating evidence from psychological, psychophysiological, neurobiological and cognitive studies suggesting that the disease-avoidance emotion of disgust is a predominant emotion experienced in a number of psychopathologies. Current evidence suggests that disgust is significantly related to small animal phobias (particularly spider phobia), blood–injection–injury phobia and obsessive–compulsive disorder contamination fears, and these are all disorders that have pr...

  13. Socially dependent avoidance learning : mechanisms of adaptive behavior

    OpenAIRE

    Lindström, Björn

    2014-01-01

    Many aspects of human social behavior are likely to be shaped by punishment, threats of punishment, and avoidance of punishment. However, surprisingly little is known about the psychological mechanisms underpinning these influences. The goal of the research presented in this thesis was to investigate how basic reinforcement-based learning processes contribute to adaptive social behavior. To this end, we investigated how human behavior is shaped by punishment and threats of punishment in simpl...

  14. Indonesia - Avoiding the Trap : Development Policy Review 2014

    OpenAIRE

    World Bank

    2014-01-01

    Within the next two decades Indonesia aspires to generate prosperity, avoid a middle-income trap, and leave no one behind as it tries to catch up with high-income economies. Can Indonesia achieve them? This report argues that the country has the potential to rise and become more prosperous and equitable. But the risk of floating in the middle is real. Which pathway the economy will take de...

  15. Collision Avoidance for Satellite Orbits and Low Thrust Transitions

    OpenAIRE

    Assmann, Kaja

    2008-01-01

    This thesis presents a capacious collision avoidance method named COLA. The method has been designed to predict collisions for Earth orbiting spacecraft (S/C) with other space-born objects. The COLA method is able to detect the point of time and the probability of collisions for objects flying on all kinds of Earth orbits, including high impulse and low thrust transfers. To guarantee an effective solution of all tasks in the process of the collision prediction, the COLA method ...

  16. Self-avoiding walks subject to a force

    International Nuclear Information System (INIS)

    We prove some theorems about self-avoiding walks attached to an impenetrable surface (i.e. positive walks) and subject to a force. Specifically we show the force dependence of the free energy is identical when the force is applied at the last vertex or at the top (confining) plane. We discuss the relevance of this result to numerical results and to a recent result about convergence rates when the walk is being pushed towards the surface. (letter)

  17. Breast Positioning during Mammography: Mistakes to be Avoided

    OpenAIRE

    Manju Bala Popli; Rahul Teotia; Meenakshi Narang; Hare Krishna

    2014-01-01

    AIMS AND OBJECTIVES Breast positioning is the key factor affecting a mammogram. If care is taken during positioning, it maximizes the amount of breast tissue being imaged, eliminates most of the artifacts, and increases sensitivity of the mammogram. This retrospective study was carried out in our department to assess correctness, and also the incorrectness of breast positioning, which need to be avoided to obtain an ideal mammogram. MATERIAL AND METHODS A total of 1369 female patients were in...

  18. Earthworm (Eisenia andrei Avoidance of Soils Treated with Cypermethrin

    Directory of Open Access Journals (Sweden)

    Mara M. de Andréa

    2011-11-01

    Full Text Available The pyrethroid insecticide cypermethrin is used for agricultural and public health campaigns. Its residues may contaminate soils and the beneficial soil organisms, like the earthworms, that may ingest the contaminated soil particles. Due to its ecological relevance, earthworms Eisenia andrei/fetida have been used in different ecotoxicological tests. The avoidance of soils treated with cypermethrin by compost worms Eisenia andrei was studied here as a bioindicator of the influence of treatment dosage and the pesticide formulation in three different agricultural soils indicated by the Brazilian environmental authorities for ecotoxicological tests. This earthworms’ behavior was studied here as a first attempt to propose the test for regulation purposes. The two-compartment test systems, where the earthworms were placed for a two-day exposure period, contained samples of untreated soil alone or together with soil treated with technical grade or wettable powder formulation of cypermethrin. After 48 h, there was no mortality, but the avoidance was clear because all earthworms were found in the untreated section of each type of soil (p < 0.05. No differences were found by the Fisher’s exact test (p ≤ 1.000 for each soil and treatment, demonstrating that the different soil characteristics, the cypermethrin concentrations and formulation, as well as the smaller amounts of soil and earthworms did not influence the avoidance behavior of the earthworms to cypermethrin. The number and range of treatments used in this study do not allow a detailed recommendation of the conditions applied here, but to the best of our knowledge, this is the first reported attempt to identify the avoidance of pesticide treated tropical soils by earthworms.

  19. Earthworm (Eisenia andrei) Avoidance of Soils Treated with Cypermethrin

    OpenAIRE

    Mara M. de Andréa; Sousa, Ana Paula A. de

    2011-01-01

    The pyrethroid insecticide cypermethrin is used for agricultural and public health campaigns. Its residues may contaminate soils and the beneficial soil organisms, like the earthworms, that may ingest the contaminated soil particles. Due to its ecological relevance, earthworms Eisenia andrei/fetida have been used in different ecotoxicological tests. The avoidance of soils treated with cypermethrin by compost worms Eisenia andrei was studied here as a bioindicator of the influence of treatment...

  20. Earthworm (Eisenia andrei) Avoidance of Soils Treated with Cypermethrin

    Science.gov (United States)

    de Sousa, Ana Paula A.; de Andréa, Mara M.

    2011-01-01

    The pyrethroid insecticide cypermethrin is used for agricultural and public health campaigns. Its residues may contaminate soils and the beneficial soil organisms, like the earthworms, that may ingest the contaminated soil particles. Due to its ecological relevance, earthworms Eisenia andrei/fetida have been used in different ecotoxicological tests. The avoidance of soils treated with cypermethrin by compost worms Eisenia andrei was studied here as a bioindicator of the influence of treatment dosage and the pesticide formulation in three different agricultural soils indicated by the Brazilian environmental authorities for ecotoxicological tests. This earthworms’ behavior was studied here as a first attempt to propose the test for regulation purposes. The two-compartment test systems, where the earthworms were placed for a two-day exposure period, contained samples of untreated soil alone or together with soil treated with technical grade or wettable powder formulation of cypermethrin. After 48 h, there was no mortality, but the avoidance was clear because all earthworms were found in the untreated section of each type of soil (p < 0.05). No differences were found by the Fisher’s exact test (p ≤ 1.000) for each soil and treatment, demonstrating that the different soil characteristics, the cypermethrin concentrations and formulation, as well as the smaller amounts of soil and earthworms did not influence the avoidance behavior of the earthworms to cypermethrin. The number and range of treatments used in this study do not allow a detailed recommendation of the conditions applied here, but to the best of our knowledge, this is the first reported attempt to identify the avoidance of pesticide treated tropical soils by earthworms. PMID:22247652

  1. Design of an obstacle avoidance system for automated guided vehicles

    OpenAIRE

    Lockwood, Stephen

    1992-01-01

    Most Industrial Automated Guided Vehicles CAGV s) follow fixed guide paths embedded in the floor or bonded to the floor surface. Whilst reliable in their basic operation, these AGV systems fail if unexpected obstacles are placed in the vehicle path. This can be a problem particularly in semi-automated factories where men and AGVs share the same environment. The perfonnance of line-guided AGVs may therefore be enhanced with a capability to avoid unexpected obstructions in the guide path. Th...

  2. Avoidance of petroleum hydrocarbons by the cod (Gadus morhua)

    OpenAIRE

    Bøhle, Bjørn

    1986-01-01

    The experimental fish were held in two different aquaria, one with three and one with two compartments. Water containing "water soluble fraction" of Fuel Oil No. 2 was introduced in one of the compartments. By means of light- and sound-based detectors, the amount of time spent by the fish in the various compartments was recorded. Although the results were somewhat contradictory, it seems that the fish avoided water containing more than 100 µg/l of the petroleum hydrocarbons.

  3. Getting Obstacle Avoidance Trajectory of Mobile Beacon for Localization

    OpenAIRE

    Huan-Qing CUI; Ying-Long WANG; Guo, Qiang; Wei, Nuo

    2010-01-01

    Localization is one of the most important technologies in wireless sensor network, and mobile beacon assisted localization is a promising localization method. The mobile beacon trajectory planning is a basic and important problem in these methods. There are many obstacles in the real world, which obstruct the moving of mobile beacon. This paper focuses on the obstacle avoidance trajectory planning scheme. After partitioning the deployment area with fixed cell decomposition, the beacon traject...

  4. A new exponent in self-avoiding walks

    International Nuclear Information System (INIS)

    Existence of a new exponent is reported in the problem of nonintersecting self-avoiding random walks. It is connected with the asymptotic behaviour of the growth of number of such walks of larger and larger length. The value of the exponent is found to be nearly 0.90 for all two-dimensional and nearly 0.96 for all three-dimensional lattices studied here. (author)

  5. Do Forecasting Methods Reduce Avoidable Error? Evidence from Forecasting Competitions

    OpenAIRE

    Steve Morlidge

    2014-01-01

    The set of M-competitions Ð comparing the forecasting accuracy of two dozen common time series methods Ð is a landmark in our understanding of how different methods fare on a variety of data types. For example, one common procedure, the trend line extrapolation available in Excel, emerged as the least accurate of all, and probably should be considered a must to avoid. Yet, as Steve Morlidge tells us here, the implications for practitioners, especially demand forecasters, are not widely unders...

  6. Avoiding Dirty Air (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2014-05-01

    As summertime approaches and warmer weather moves in, air pollution will become an increasing problem across the U.S. People with asthma are especially impacted by deteriorating air quality. In this podcast, Dr. Suzanne Beavers discusses ways to avoid the negative impacts of air pollution.  Created: 5/1/2014 by MMWR.   Date Released: 5/1/2014.

  7. Odour avoidance learning in the larva of Drosophila melanogaster

    Indian Academy of Sciences (India)

    Sukant Khurana; Mohammed Bin AbuBaker; Obaid Siddiqi

    2009-10-01

    Drosophila larvae can be trained to avoid odours associated with electric shock. We describe here, an improved method of aversive conditioning and a procedure for decomposing learning retention curve that enables us to do a quantitative analysis of memory phases, short term (STM), middle term (MTM) and long term (LTM) as a function of training cycles. The same method of analysis when applied to learning mutants dunce, amnesiac, rutabaga and radish reveals memory deficits characteristic of the mutant strains.

  8. The role of uncertainty avoidance in foreign investment bias

    OpenAIRE

    Erdogan, Burcu

    2014-01-01

    In this paper, I explore the determinants of foreign bias in international portfolio investment focusing on a behavioral explanation. Specifically, I investigate whether investors having a stronger uncertainty aversion perceive a foreign country to be more unfamiliar than those with less such aversion. I exploit systematic differences in uncertainty avoidance across countries in my analysis using Hofstede's (1980, 2001) findings for this purpose. I show that less familiarity with the foreign ...

  9. Avoiding Invalid Instruments and Coping with Weak Instruments

    OpenAIRE

    Michael P. Murray

    2006-01-01

    Archimedes said, "Give me the place to stand, and a lever long enough, and I will move the Earth." Economists have their own powerful lever: the instrumental variable estimator. The instrumental variable estimator can avoid the bias that ordinary least squares suffers when an explanatory variable in a regression is correlated with the regression's disturbance term. But, like Archimedes lever, instrumental variable estimation requires both a valid instrument on which to stand and an instrument...

  10. Disgust as an adaptive system for disease avoidance behaviour.

    Science.gov (United States)

    Curtis, Valerie; de Barra, Mícheál; Aunger, Robert

    2011-02-12

    Disgust is an evolved psychological system for protecting organisms from infection through disease avoidant behaviour. This 'behavioural immune system', present in a diverse array of species, exhibits universal features that orchestrate hygienic behaviour in response to cues of risk of contact with pathogens. However, disgust is also a dynamic adaptive system. Individuals show variation in pathogen avoidance associated with psychological traits like having a neurotic personality, as well as a consequence of being in certain physiological states such as pregnancy or infancy. Three specialized learning mechanisms modify the disgust response: the Garcia effect, evaluative conditioning and the law of contagion. Hygiene behaviour is influenced at the group level through social learning heuristics such as 'copy the frequent'. Finally, group hygiene is extended symbolically to cultural rules about purity and pollution, which create social separations and are enforced as manners. Cooperative hygiene endeavours such as sanitation also reduce pathogen prevalence. Our model allows us to integrate perspectives from psychology, ecology and cultural evolution with those of epidemiology and anthropology. Understanding the nature of disease avoidance psychology at all levels of human organization can inform the design of programmes to improve public health. PMID:21199843

  11. Cavity Femtochemistry: Manipulating Nonadiabatic Dynamics at Avoided Crossings.

    Science.gov (United States)

    Kowalewski, Markus; Bennett, Kochise; Mukamel, Shaul

    2016-06-01

    Molecular potential energy surfaces can be actively manipulated by light. This is usually done by strong classical laser light but was recently demonstrated for the quantum field in an optical cavity. The photonic vacuum state of a localized cavity mode can be strongly mixed with the molecular degrees of freedom to create hybrid field-matter states known as polaritons. We simulate the avoided crossing of sodium iodide in a cavity by incorporating the quantized cavity field into the nuclear wave packet dynamics calculation. The quantized field is represented on a numerical grid in quadrature space, thus avoiding the limitations set by the rotating wave approximation (RWA) when the field is expanded in Fock space. This approach allows the investigation of cavity couplings in the vicinity of naturally occurring avoided crossings and conical intersections, which is too expensive in the fock space expansion when the RWA does not apply. Numerical results show how the branching ratio between the covalent and ionic dissociation channels can be strongly manipulated by the optical cavity. PMID:27186666

  12. Reinforcement learning for congestion-avoidance in packet flow

    Science.gov (United States)

    Horiguchi, Tsuyoshi; Hayashi, Keisuke; Tretiakov, Alexei

    2005-04-01

    Occurrence of congestion of packet flow in computer networks is one of the unfavorable problems in packet communication and hence its avoidance should be investigated. We use a neural network model for packet routing control in a computer network proposed in a previous paper by Horiguchi and Ishioka (Physica A 297 (2001) 521). If we assume that the packets are not sent to nodes whose buffers are already full of packets, then we find that traffic congestion occurs when the number of packets in the computer network is larger than some critical value. In order to avoid the congestion, we introduce reinforcement learning for a control parameter in the neural network model. We find that the congestion is avoided by the reinforcement learning and at the same time we have good performance for the throughput. We investigate the packet flow on computer networks of various types of topology such as a regular network, a network with fractal structure, a small-world network, a scale-free network and so on.

  13. The self-avoiding walk in a strip

    CERN Document Server

    Dyhr, Ben; Kennedy, Tom; Lawler, Gregory F; Passon, Shane

    2010-01-01

    We review the existence of the infinite length self-avoiding walk in the half plane and its relationship to bridges. We prove that this probability measure is also given by the limit as $\\beta \\rightarrow \\beta_c-$ of the probability measure on all finite length walks $\\omega$ with the probability of $\\omega$ proportional to $\\beta_c^{|\\omega|}$ where $|\\omega|$ is the number of steps in $\\omega$. The self-avoiding walk in a strip $\\{z : 0<\\Im(z)avoiding walks $\\omega$ in the strip which start at the origin and end somewhere on the top boundary with probability proportional to $\\beta_c^{|\\omega|}$ We prove that this probability measure may be obtained by conditioning the SAW in the half plane to have a bridge at height $y$. This observation is the basis for simulations to test conjectures on the distribution of the endpoint of the SAW in a strip and the relationship between the distribution of this strip SAW and SLE$_{8/3}$.

  14. A Robot Manipulator with Adaptive Fuzzy Controller in Obstacle Avoidance

    Science.gov (United States)

    Sreekumar, Muthuswamy

    2016-03-01

    Building robots and machines to act within a fuzzy environment is a problem featuring complexity and ambiguity. In order to avoid obstacles, or move away from it, the robot has to perform functions such as obstacle identification, finding the location of the obstacle, its velocity, direction of movement, size, shape, and so on. This paper presents about the design, and implementation of an adaptive fuzzy controller designed for a 3 degree of freedom spherical coordinate robotic manipulator interfaced with a microcontroller and an ultrasonic sensor. Distance between the obstacle and the sensor and its time rate are considered as inputs to the controller and how the manipulator to take diversion from its planned trajectory, in order to avoid collision with the obstacle, is treated as output from the controller. The obstacles are identified as stationary or moving objects and accordingly adaptive self tuning is accomplished with three set of linguistic rules. The prototype of the manipulator has been fabricated and tested for collision avoidance by placing stationary and moving obstacles in its planned trajectory. The performance of the adaptive control algorithm is analyzed in MATLAB by generating 3D fuzzy control surfaces.

  15. Hierarchical brain networks active in approach and avoidance goal pursuit

    Directory of Open Access Journals (Sweden)

    Jeffrey Martin Spielberg

    2013-06-01

    Full Text Available Effective approach/avoidance goal pursuit is critical for attaining long-term health and well-being. Research on the neural correlates of key goal pursuit processes (e.g., motivation has long been of interest, with lateralization in prefrontal cortex being a particularly fruitful target of investigation. However, this literature has often been limited by a lack of spatial specificity and has not delineated the precise aspects of approach/avoidance motivation involved. Additionally, the relationships among brain regions (i.e., network connectivity vital to goal pursuit remain largely unexplored. Specificity in location, process, and network relationship is vital for moving beyond gross characterizations of function and identifying the precise cortical mechanisms involved in motivation. The present paper integrates research using more spatially specific methodologies (e.g., functional magnetic resonance imaging with the rich psychological literature on approach/avoidance to propose an integrative network model that takes advantage of the strengths of each of these literatures.

  16. Autonomous obstacle avoidance using visual fixation and looming

    Science.gov (United States)

    Joarder, Kunal; Raviv, Daniel

    1992-11-01

    This paper describes a vision-based method for avoiding obstacles using the concepts of visual looming and fixating motion. Visual looming refers to the expansion of images of objects in the retina. Usually, this is due to the decreasing distance between the observer and the object. An increasing looming value signifies an increasing threat of collision with the object. The visual task of avoiding collision can be further simplified by purposive control of visual fixation at the objects in front of the moving camera. Using these two basic concepts real time obstacle avoidance in a tight perception-action loop is implemented. Three-dimensional space in front of the camera is divided into zones with various degrees of looming-based threat of collision. For each obstacle seen by a fixating camera, looming and its time derivative are calculated directly from the 2-D image. Depending on the threat posed by an obstacle, a course change is dictated. This looming based approach is simple, independent of the size of the 3-D object and its range and involves simple quantitative measurements. Results pertinent to a camera on a robot arm navigating between obstacles are presented.

  17. A Robot Manipulator with Adaptive Fuzzy Controller in Obstacle Avoidance

    Science.gov (United States)

    Sreekumar, Muthuswamy

    2016-07-01

    Building robots and machines to act within a fuzzy environment is a problem featuring complexity and ambiguity. In order to avoid obstacles, or move away from it, the robot has to perform functions such as obstacle identification, finding the location of the obstacle, its velocity, direction of movement, size, shape, and so on. This paper presents about the design, and implementation of an adaptive fuzzy controller designed for a 3 degree of freedom spherical coordinate robotic manipulator interfaced with a microcontroller and an ultrasonic sensor. Distance between the obstacle and the sensor and its time rate are considered as inputs to the controller and how the manipulator to take diversion from its planned trajectory, in order to avoid collision with the obstacle, is treated as output from the controller. The obstacles are identified as stationary or moving objects and accordingly adaptive self tuning is accomplished with three set of linguistic rules. The prototype of the manipulator has been fabricated and tested for collision avoidance by placing stationary and moving obstacles in its planned trajectory. The performance of the adaptive control algorithm is analyzed in MATLAB by generating 3D fuzzy control surfaces.

  18. Obstacle avoidance in social groups: new insights from asynchronous models.

    Science.gov (United States)

    Croft, Simon; Budgey, Richard; Pitchford, Jonathan W; Wood, A Jamie

    2015-05-01

    For moving animals, the successful avoidance of hazardous obstacles is an important capability. Despite this, few models of collective motion have addressed the relationship between behavioural and social features and obstacle avoidance. We develop an asynchronous individual-based model for social movement which allows social structure within groups to be included. We assess the dynamics of group navigation and resulting collision risk in the context of information transfer through the system. In agreement with previous work, we find that group size has a nonlinear effect on collision risk. We implement examples of possible network structures to explore the impact social preferences have on collision risk. We show that any social heterogeneity induces greater obstacle avoidance with further improvements corresponding to groups containing fewer influential individuals. The model provides a platform for both further theoretical investigation and practical application. In particular, we argue that the role of social structures within bird flocks may have an important role to play in assessing the risk of collisions with wind turbines, but that new methods of data analysis are needed to identify these social structures. PMID:25833245

  19. Hear no evil: The effect of auditory warning signals on avian innate avoidance, learned avoidance and memory

    Directory of Open Access Journals (Sweden)

    Emma C. SIDDALL, Nicola M. MARPLES

    2011-04-01

    Full Text Available Many aposematic insect species advertise their toxicity to potential predators using olfactory and auditory signals, in addition to visual signals, to produce a multimodal warning display. The olfactory signals in these displays may have interesting effects, such as eliciting innate avoidance against novel colored prey, or improving learning and memory of defended prey. However, little is known about the effects of such ancillary signals when they are auditory rather than olfactory. The few studies that have investigated this question have provided conflicting results. The current study sought to clarify and extend understanding of the effects of prey auditory signals on avian predator responses. The domestic chick Gallus gallus domesticus was used as a model avian predator to examine how the defensive buzzing sound of a bumblebee Bombus terrestris affected the chick’s innate avoidance behavior, and the learning and memory of prey avoidance. The results demonstrate that the buzzing sound had no effect on the predator’s responses to unpalatable aposematically colored crumbs, suggesting that the agitated buzzing of B. terrestris may provide no additional protection from avian predators [Current Zoology 57 (2: 197–207, 2011].

  20. Hear no evil:The effect of auditory warning signals on avian innate avoidance,learned avoidance and memory

    Institute of Scientific and Technical Information of China (English)

    Emma C.SIDDALL; Nicola M.MARPLES

    2011-01-01

    Many aposematic insect species advertise their toxicity to potential predators using olfactory and auditory signals,in addition to visual signals,to produce a multimodal warning display.The olfactory signals in these displays may have interesting effects,such as eliciting innate avoidance against novel colored prey,or improving learning and memory of defended prey.However,little is known about the effects of such ancillary signals when they are auditory rather than olfactory.The few studies that have investigated this question have provided confficting results.The current study sought to clarify and extend understanding of the effects of prey auditory signals on avian predator responses.The domestic chick Gallus gallus domesticus was used as a model avian predator to examine how the defensive buzzing sound of a bumblebee Bombus terrestris affected the chick's innate avoidance behavior,and the learning and memory of prey avoidance.The resuits demonstrate that the buzzing sound had no effect on the predator's responses to unpalalable aposematically colored crumbs,suggesting that the agitated buzzing of B.terrestris may provide no additional protection from avian predators.

  1. The Relationship among Student Basic Need Satisfaction, Approaches to Learning, Reporting of Avoidance Strategies and Achievement

    Science.gov (United States)

    Betoret, Fernando Domenech; Artiga, Amparo Gomez

    2011-01-01

    Introduction: This study examines the relationship between student basic need satisfaction (autonomy, competence, relatedness and belonging), their reporting of approaches to learning (deep and surface), their reporting of avoidance strategies (avoidance of effort and challenge, avoidance of help seeking and preference to avoid novelty) and…

  2. STRES DITINJAU DARI ACTIVE COPING, AVOIDANCE COPING DAN NEGATIVE COPING.

    Directory of Open Access Journals (Sweden)

    Triantoro Safaria

    2012-11-01

    Full Text Available AbstrakStres  merupakan bagian dari kehidupan dan  kehidupan tidak lepas dari stres. Stresbisa dialami siapa saja, dari kanak-kanak hingga  lanjut usia.  Stres bisa bersifat akut danbisa pula bersifat  kronis.  Banyak penelitian empiris yang membuktikan bahwa stres berdampaksecara negatif bagi kesehatan tubuh  dan  kesejahteraan psikologis. Namun banyak faktoryang berpengaruh terhadap stres. Diantara faktor  faktor tersebut adalah strategi  coping yangdigunakan individu.Penelitian ini menguji hubungan antara  tiga strategi coping yaitu active coping,avoidance coping  dan  negative coping  dengan  stres  pada mahasiswa. Subyekpenelitian berjumlah  41 orang yang merupakan mahasiswa psikologi Universitas AhmadDahlan Yogyakarta.Berdasarkan hasil  analisis regresi menunjukkan tidak ada hubungan  yang signifikanantara   active coping, negative coping dan  avoidance coping  secara bersama-sama dengan  stres R = 0.045 F = 1.631 p = 0.199. Hasil uji korelasi  product momentpearson antara  active coping  dengan stres menunjukkan adanya hubungan negatif yangtidak signifikan r = - 0.034 p =  0.417. Korelasi antara avoidance coping  dengan stresmenunjukkan adanya hubungan positif yang tidak signifikan r = 0.113 p = 0.241.  Korelasiantara  negative coping  dengan stres menunjukkan hubungan positif yang signifikan  r =0.340 p = 0.015. Negative  coping  menyumbang  9.3 %  terhadap  stres. Ini menunjukkanmasih terdapat  90.7 % pengaruh variabel lain yang terhadap stres.

  3. The Relationship Between Approach-Avoidance Behaviors and Hardiness

    Directory of Open Access Journals (Sweden)

    Ahmad Ali-Poor

    2012-10-01

    Full Text Available Background: Hardiness as a personality trait is an important factor in directing people to success. An explanation for this trait is the psychobiological explanation including the Gray’s theory of Brian/behavioral systems. This study has examined the relationship between the Brian/behavioral systems and hardiness in successful people.Materials and Methods: In this study, 60 successful students (medical students in their final two years of medical school and 60 ordinary subjects were studied using two personality questionnaires (Gary-Wilson and Hardiness Questionnaires as well as Pearson’s correlation statistical technique, regression, and independent t-test.Results: Data analysis showed that the activity level of behavioral activation system (p=0.002: active avoidance and p> 0.001: approach behavior and hardiness (p>0.001 is significantly higher in successful people than ordinary subjects and that there is a significant relationship between hardiness and two components of behavioral activation system and one component of behavioral inhibition system (i.e. active avoidance (p>0.01. Conclusion: According to the findings, only two components of approach behavior and active avoidance can predict the variable hardiness. However, these two components are considered as only one of the predictors of success and there are undoubtedly many other factors involved in this regard. Overall, this study can lead to the identification of new factors involved in the success occurrence that consideration of them can help understanding the individual differences in order to perform effective psychological interventions to improve the level of effort and success in people.

  4. A Global Obstacle-avoidance Map for Anthropomorphic Arms

    Directory of Open Access Journals (Sweden)

    Cheng Fang

    2014-07-01

    Full Text Available More and more humanoid robots are used in human society, and they face a wide variety of complicated manipulation tasks, which are mainly to be achieved by their anthropomorphic arms. Obstacle avoidance for the anthropomorphic arm must be a fundamental consideration to guarantee the successful implementation of these tasks. Different from traditional methods searching for feasible or optimal collision-free solutions for the anthropomorphic arm, a global obstacle- avoidance map for the whole arm is proposed to indicate the complete set of feasible solutions. In this map, the motion of the arm can be appropriately planned to intuitively control the configuration of the arm in motion. First, the cubic spline function is adopted to interpolate some well-chosen path points to generate a smooth collision-free path for the wrist of the anthropomorphic arm. Second, based on the path function of the wrist, the time and the self-rotation angle of the arm about the “shoulder-wrist” axis are used to parameterize all possible configurations of the arm so that a global two- dimensional map considering the obstacle avoidance can be established. Subsequently, a collision-free self-rotation angle profile of the arm can be well planned. Finally, the joint trajectories of a specific anthropomorphic arm, which correspond to the planned path of the wrist and self-rotation angle profile of the arm, can be solved on the basis of the general kinematic analysis of the anthropomorphic arm, and the specific structure. Several simulations are conducted to verify that the proposed collision-free motion planning method for anthropomorphic arms has some advantages and can be regarded as a convenient and intuitive tool to control the configuration of the anthropomorphic arm in motion, without collision with obstacles in its surroundings.

  5. Lunar Landing Trajectory Design for Onboard Hazard Detection and Avoidance

    Science.gov (United States)

    Paschall, Steve; Brady, Tye; Sostaric, Ron

    2009-01-01

    The Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project is developing the software and hardware technology needed to support a safe and precise landing for the next generation of lunar missions. ALHAT provides this capability through terrain-relative navigation measurements to enhance global-scale precision, an onboard hazard detection system to select safe landing locations, and an Autonomous Guidance, Navigation, and Control (AGNC) capability to process these measurements and safely direct the vehicle to a landing location. This paper focuses on the key trajectory design issues relevant to providing an onboard Hazard Detection and Avoidance (HDA) capability for the lander. Hazard detection can be accomplished by the crew visually scanning the terrain through a window, a sensor system imaging the terrain, or some combination of both. For ALHAT, this hazard detection activity is provided by a sensor system, which either augments the crew s perception or entirely replaces the crew in the case of a robotic landing. Detecting hazards influences the trajectory design by requiring the proper perspective, range to the landing site, and sufficient time to view the terrain. Following this, the trajectory design must provide additional time to process this information and make a decision about where to safely land. During the final part of the HDA process, the trajectory design must provide sufficient margin to enable a hazard avoidance maneuver. In order to demonstrate the effects of these constraints on the landing trajectory, a tradespace of trajectory designs was created for the initial ALHAT Design Analysis Cycle (ALDAC-1) and each case evaluated with these HDA constraints active. The ALHAT analysis process, described in this paper, narrows down this tradespace and subsequently better defines the trajectory design needed to support onboard HDA. Future ALDACs will enhance this trajectory design by balancing these issues and others in an overall system

  6. Avoiding maladaptation to climate change: towards guiding principles

    International Nuclear Information System (INIS)

    The recent publication of the Physical Science Basis volume of IPCC's Fifth Assessment Report reaffirms an already known conclusion: even drastic reductions of global greenhouse gas emissions will be insufficient to avoid some of the impacts of climate change, and is becoming increasingly clear that the temperature increase by the end of the century is likely to exceed the official target of +2 deg. C. Urgent efforts are thus more than ever needed to support socio-ecological systems threatened by climate change, but how to make adaptation happen on the ground remains vague. Consequently, there is a real risk that climate funding may support initiatives that are actually harmful for the socio-ecological systems, i.e. that foster adaptation in the short-term but insidiously affect systems' long-term vulnerability and/or adaptive capacity to climate change. This generally defines 'mal-adaptation', and this paper affirms that avoiding mal-adaptation is a first key concrete step towards adaptation in a broader sense. Focusing on coastal areas at a local scale and with the aim of providing insights to help avoiding mal-adaptation to climate change on the ground, this paper develops eleven practice-oriented guidelines that address the environmental, socio-cultural and economic dimensions of adaptation initiatives (policies, plans, projects). Based upon this, it affirms that the more guidelines an initiative addresses, the lower will be the risk of mal-adaptation. Together, these guidelines and this assumption constitute the 'Assessment framework' for approaching mal-adaptation to climate change at a local level. (author)

  7. Autonomous Navigation and Obstacle Avoidance of a Micro-bus

    Directory of Open Access Journals (Sweden)

    Carlos Fernández

    2013-04-01

    Full Text Available At present, the topic of automated vehicles is one of the most promising research areas in the field of Intelligent Transportation Systems (ITS. The use of automated vehicles for public transportation also contributes to reductions in congestion levels and to improvements in traffic flow. Moreover, electrical public autonomous vehicles are environmentally friendly, provide better air quality and contribute to energy conservation. The driverless public transportation systems, which are at present operating in some airports and train stations, are restricted to dedicated roads and exhibit serious trouble dynamically avoiding obstacles in the trajectory. In this paper, an electric autonomous mini-bus is presented. All datasets used in this article were collected during the experiments carried out in the demonstration event of the 2012 IEEE Intelligent Vehicles Symposium that took place in Alcalá de Henares (Spain. The demonstration consisted of a route 725 metres long containing a list of latitude-longitude points (waypoints. The mini-bus was capable of driving autonomously from one waypoint to another using a GPS sensor. Furthermore, the vehicle is provided with a multi-beam Laser Imaging Detection and Ranging (LIDAR sensor for surrounding reconstruction and obstacle detection. When an obstacle is detected in the planned path, the planned route is modified in order to avoid the obstacle and continue its way to the end of the mission. On the demonstration day, a total of 196 attendees had the opportunity to get a ride on the vehicles. A total of 28 laps were successfully completed in full autonomous mode in a private circuit located in the National Institute for Aerospace Research (INTA, Spain. In other words, the system completed 20.3 km of driverless navigation and obstacle avoidance.

  8. Avoiding tar formation in biocoke production from waste biomass

    International Nuclear Information System (INIS)

    This paper focuses in avoiding tar formation and in optimizing pyrolysis gas (maximizing H2 and CO) in the production of biocoke from waste lignocellulosic biomass. In order to obtain metallurgical grade biochar (biocoke) slow heating rate and high temperature are required. Under such conditions useless pyrolysis liquids, mainly composed of water together with some heavy-sticky tars, are obtained. In order to make biocoke a cost-effective process it is necessary to optimize pyrolysis vapors avoiding tar formation and maximizing the amount and quality of both coke and gases. With this objective, in this work different heating rates (3–20 °C min−1) and catalysts (zeolite, Ni/CeO2–Al2O3) have been tested in a two step pyrolysis process. Olive tree cuttings have been pyrolyzed in a 3.5 L batch reactor at 750 °C and the vapors generated have been thermally and catalytically treated at 900 °C in a second tubular reactor. About 25 wt.% biocoke useful as reducing agent in certain metallurgical processes, ≈57 wt.% gases with near 50 vol.% H2, and no tar production has been achieved when a heating rate of 3 °C min−1 and the homemade Ni/CeO2–Al2O3 catalyst were used. - Highlights: • Metallurgical grade biochar was obtained by olive waste pyrolysis. • Low heating rates avoid tar formation and increase gas and biochar yields. • Ni/CeO2–Al2O3 was better than HZSM5 zeolite for vapor upgrading in a second step. • Ni/CeO2–Al2O3 and 3 °C min−1 gave the maximum H2, gas and biochar yields

  9. Dyck Paths, Standard Young Tableaux, and Pattern Avoiding Permutations

    CERN Document Server

    Gudmundsson, Hilmar

    2009-01-01

    We present a generating function and a closed counting formula in two variables that enumerate a family of classes of permutations that avoid or contain an increasing pattern of length three and have a prescribed number of occurrences of another pattern of length three. This gives a refinement of some previously studied statistics, most notably one by Noonan. The formula is also shown to enumerate a family of classes of Dyck paths and Standard Young Tableaux, and a bijection is given between the corresponding classes of these two families of objects. Finally, the results obtained are used to solve an optimization problem for a certain card game.

  10. Conflict Detection Metrics for Aircraft Sense and Avoid Systems

    OpenAIRE

    Lindsten, Fredrik; Nordlund, Per-Johan; Gustafsson, Fredrik

    2009-01-01

    The task of an airborne collision avoidance system is to continuously evaluate the risk of collision and in the case of too high risk initiate an evasive action. The traditional way to assess risk is to focus on a critical point of time. A recently proposed alternative is to evaluate the cumulated risk over time. It is the purpose of this contribution to evaluate the difference between these two concepts and also to validate an approximate method for computing the cumulated risk, suitable for...

  11. Avoiding Intellectual Stagnation: The Starship as an Expander of Minds

    CERN Document Server

    Crawford, Ian A

    2015-01-01

    Interstellar exploration will advance human knowledge and culture in multiple ways. Scientifically, it will advance our understanding of the interstellar medium, stellar astrophysics, planetary science and astrobiology. In addition, significant societal and cultural benefits will result from a programme of interstellar exploration and colonisation. Most important will be the cultural stimuli resulting from expanding the horizons of human experience, and increased opportunities for the spread and diversification of life and culture through the Galaxy. Ultimately, a programme of interstellar exploration may be the only way for human (and post-human) societies to avoid the intellectual stagnation predicted for the "end of history".

  12. Intelligent Surveillance Robot with Obstacle Avoidance Capabilities Using Neural Network.

    Science.gov (United States)

    Budiharto, Widodo

    2015-01-01

    For specific purpose, vision-based surveillance robot that can be run autonomously and able to acquire images from its dynamic environment is very important, for example, in rescuing disaster victims in Indonesia. In this paper, we propose architecture for intelligent surveillance robot that is able to avoid obstacles using 3 ultrasonic distance sensors based on backpropagation neural network and a camera for face recognition. 2.4 GHz transmitter for transmitting video is used by the operator/user to direct the robot to the desired area. Results show the effectiveness of our method and we evaluate the performance of the system. PMID:26089863

  13. Sequential Probability Ratio Test for Collision Avoidance Maneuver Decisions

    Science.gov (United States)

    Carpenter, J. Russell; Markley, F. Landis

    2010-01-01

    When facing a conjunction between space objects, decision makers must chose whether to maneuver for collision avoidance or not. We apply a well-known decision procedure, the sequential probability ratio test, to this problem. We propose two approaches to the problem solution, one based on a frequentist method, and the other on a Bayesian method. The frequentist method does not require any prior knowledge concerning the conjunction, while the Bayesian method assumes knowledge of prior probability densities. Our results show that both methods achieve desired missed detection rates, but the frequentist method's false alarm performance is inferior to the Bayesian method's

  14. Essential Maths for Engineering and Construction How to Avoid Mistakes

    CERN Document Server

    Breach, Mark

    2011-01-01

    Don,t let your mathematical skills fail you! In Engineering, Construction, and Science examinations, marks are often lost through carelessness or from not properly understanding the mathematics involved. When there are only a few marks on offer for a part of a question, there may be full marks for a right answer and none for a wrong one, regardless of the thought that went into the answer. If you want to avoid losing these marks by improving the clarity both of your mathematical work and your mathematical understanding, then Essential Maths for Engineering and Construction is the book for you.

  15. Self-avoiding walks on scale-free networks

    OpenAIRE

    Herrero, Carlos P.

    2004-01-01

    Several kinds of walks on complex networks are currently used to analyze search and navigation in different systems. Many analytical and computational results are known for random walks on such networks. Self-avoiding walks (SAWs) are expected to be more suitable than unrestricted random walks to explore various kinds of real-life networks. Here we study long-range properties of random SAWs on scale-free networks, characterized by a degree distribution $P(k) \\sim k^{-\\gamma}$. In the limit of...

  16. Self-avoiding effective strings in lattice gauge theories

    International Nuclear Information System (INIS)

    It is shown that the effective string recently introduced to describe the long distance dynamics of 3D gauge systems in the confining phase has an intriguing description in terms of models of 2D self-avoiding walks in the dense phase. The deconfinement point, where the effective string becomes N=2 supersymmetric, may then be interpreted as the tricritical Θ point where the polymer chain undergoes a collapse transition. As a consequence, a universal value of the deconfinement temperature is predicted. (orig.)

  17. Self-Avoiding Walks Over Adaptive Triangular Grids

    Science.gov (United States)

    Heber, Gerd; Biswas, Rupak; Gao, Guang R.; Saini, Subhash (Technical Monitor)

    1999-01-01

    Space-filling curves is a popular approach based on a geometric embedding for linearizing computational meshes. We present a new O(n log n) combinatorial algorithm for constructing a self avoiding walk through a two dimensional mesh containing n triangles. We show that for hierarchical adaptive meshes, the algorithm can be locally adapted and easily parallelized by taking advantage of the regularity of the refinement rules. The proposed approach should be very useful in the runtime partitioning and load balancing of adaptive unstructured grids.

  18. Self-avoiding walks in a slab with attractive walls

    International Nuclear Information System (INIS)

    We consider a self-avoiding walk confined between two parallel planes (or lines), with an energy term associated with each vertex of the walk in the confining planes. We allow the energy terms to be different for the top and bottom planes. We use exact enumeration and Monte Carlo methods to investigate the force between the confining planes and how it depends on the width of the slab and on the interaction energy terms. The phase diagram is qualitatively similar to that found for a directed walk model. (letter to the editor)

  19. On the importance sampling of self-avoiding walks

    OpenAIRE

    Bousquet-Mélou, Mireille

    2014-01-01

    In a 1976 paper published in Science, Knuth presented an algorithm to sample (non-uniform) self-avoiding walks crossing a square of side k. From this sample, he constructed an estimator for the number of such walks. The quality of this estimator is directly related to the (relative) variance of a certain random variable X_k. From his experiments, Knuth suspected that this variance was extremely large (so that the estimator would not be very efficient). But how large? For the analogous Rosenbl...

  20. Scaling of the atmosphere of self-avoiding walks

    OpenAIRE

    Owczarek, A. L.; Prellberg, T.

    2008-01-01

    The number of free sites next to the end of a self-avoiding walk is known as the atmosphere. The average atmosphere can be related to the number of configurations. Here we study the distribution of atmospheres as a function of length and how the number of walks of fixed atmosphere scale. Certain bounds on these numbers can be proved. We use Monte Carlo estimates to verify our conjectures. Of particular interest are walks that have zero atmosphere, which are known as trapped. We demonstrate th...

  1. Counting self-avoiding walks on free products of graphs

    OpenAIRE

    Gilch, Lorenz A.; Müller, Sebastian

    2015-01-01

    The connective constant $\\mu(G)$ of a graph $G$ is the asymptotic growth rate of the number $\\sigma_{n}$ of self-avoiding walks of length $n$ in $G$ from a given vertex. We prove a formula for the connective constant for free products of quasi-transitive graphs and show that $\\sigma_{n}\\sim A_{G} \\mu(G)^{n}$ for some constant $A_{G}$ that depends on $G$. In the case of finite products $\\mu(G)$ can be calculated explicitly and is shown to be an algebraic number.

  2. Weakly directed self-avoiding walks (conference version)

    OpenAIRE

    Bacher, Axel; Bousquet-Mélou, Mireille

    2010-01-01

    We define a new family of self-avoiding walks (SAW) on the square lattice, called weakly directed walks. These walks have a simple characterization in terms of the irreducible bridges that compose them. We determine their generating function. This series has a complex singularity structure and in particular, is not D-finite. The growth constant is approximately 2.54 and is thus larger than that of all natural families of SAW enumerated so far (but smaller than that of general SAW, which is ab...

  3. Potential-based obstacle avoidance in formation control

    Institute of Scientific and Technical Information of China (English)

    Jia WANG; Xiaobei WU; Zhiliang XU

    2008-01-01

    Based on the double integrator mathematic model,a new kind of potential function is presented in this paper by referring to the concepts of the electric field;then a new formation control method is proposed,in which the potential functions are used between agent-agent and between agent-obstacle,while state feedback control is applied for the agent and its goal.This strategy makes the whole potential field simpler and helps avoid some local minima.The stability of this combination of potential functions and state feedback control is proven.Some simulations are presented to show the rationality of this control method.

  4. Indigenous knowledge in the science curriculum: avoiding neo-colonialism

    Science.gov (United States)

    Ryan, Ann

    2008-09-01

    Science education in Papua New Guinea has been influenced by neo-colonial practices that have significantly contributed to the silencing of the Papua New Guinea voice. This silencing has led to the production of science curriculum documents that are irrelevant to the students for whom they are written. To avoid being caught up in neo-colonial practices, Western science educators ought to consider the notion of cultural mediators. This position, I argue, infers an obligation to take responsibility for their actions and to consider postcolonial discourses as a way of understanding the relationships and dialogue between different ways of knowing.

  5. Book Review of How to avoid becoming a victim

    OpenAIRE

    Bowers, J. Jr.,

    2007-01-01

    The book, Cybercrime: How to avoid becoming a victim, written by H.  Thomas Milhorn, MD, Ph.D. sets out to educate its readers about the many different types of cyber crimes and ways in which internet users can protect themselves from becoming victims.  According to the author, cyber crime is identified as “any type of activity that uses the Internet to commit a crime (p.1)”.  A broad area of cyber crime is covered throughout the book with special emphasis given to ...

  6. How to Avoid the Pitfalls of Legal English

    OpenAIRE

    Chovancová Barbora; Hradilová Alena

    2012-01-01

    The present manual is intended for Czech students of law as well as other professionals interested in finding out more about legal English. This brief guide provides a few quick tips on improving one's legal English and helps users to avoid making the most common mistakes. It consists of four parts: (1) lawyers and the legal profession, (2) the meanings of 'law', (3) language and law, and (4) legal false friends. Tato příručka byla vytvořena pro české studenty práva a pro další odborníky, ...

  7. Intelligent Surveillance Robot with Obstacle Avoidance Capabilities Using Neural Network

    Science.gov (United States)

    2015-01-01

    For specific purpose, vision-based surveillance robot that can be run autonomously and able to acquire images from its dynamic environment is very important, for example, in rescuing disaster victims in Indonesia. In this paper, we propose architecture for intelligent surveillance robot that is able to avoid obstacles using 3 ultrasonic distance sensors based on backpropagation neural network and a camera for face recognition. 2.4 GHz transmitter for transmitting video is used by the operator/user to direct the robot to the desired area. Results show the effectiveness of our method and we evaluate the performance of the system. PMID:26089863

  8. Potentially avoidable perinatal deaths in Denmark and Sweden 1991

    DEFF Research Database (Denmark)

    Langhoff-Roos, J; Borch-Christensen, H; Larsen, S; Lindberg, B; Wennergren, M

    1996-01-01

    BACKGROUND: Since 1950 the perinatal mortality has been significantly higher in Denmark than in Sweden. In 1991 the rate in Denmark was 8.0/1000 deliveries compared to 6.5/1000 in Sweden. An international audit was designed to investigate whether the perinatal death rates in the two countries to...... some extent could reflect differences in the quality of care, indicated by the numbers of perinatal deaths in categories of potentially avoidable deaths. MATERIAL AND METHODS: Medical records of 97% of all perinatal deaths in 1991 in the two countries were analyzed. A new classification focusing on...

  9. Micro-Controller Based Obstacle Avoiding Autonomous Robot

    OpenAIRE

    Subhranil Som; Arjun Shome

    2014-01-01

    Main aim of this paperwork is to study development of the obstacle avoiding spy robot, which can be operated manually as per the operator wants to take control of the robot himself, it also can be autonomous in its actions while intelligently moving itself by detecting the obstacles in front of it by the help of the obstacle detectable circuit. The robot is in form of a vehicle mounted with a web cam, which acquires and sends video as per the robots eye view to a TV or PC via ...

  10. Detection and Avoidance of Collisions: the REACT Model

    OpenAIRE

    Sauer, Craig; Andersen, Goerge J.; Saidpour, Asad

    2004-01-01

    An important perceptual task during driving is the ability to detect and avoid collisions. Failure to accurately perform this task can have serious consequences for the driver and passengers. The present research developed and tested a model of car following by human drivers, as part of a general model under development of a human driver. Unlike other car following models that are based on 3D parameters (e.g., range or distance) the present model is based on the visual information available t...

  11. On infinite words avoiding a finite set of squares

    OpenAIRE

    Sanderson, Yasmine B.

    2013-01-01

    Building an infinite square-free word by appending one letter at a time while simultaneously avoiding the creation of squares is most likely to fail. When the alphabet has two letters this approach is impossible. When the alphabet has three or more letters, one will most probably create a word in which the addition of any letter invariably creates a square. When one restricts the set of undesired squares to a finite one, this can be possible. We study the constraints on the alphabet and the s...

  12. Must-Take Cards: Merchant Discounts and Avoided Costs

    OpenAIRE

    Rochet, Jean-Charles; Tirole, Jean

    2011-01-01

    Antitrust authorities often argue that merchants cannot reasonably turn down payment cards and therefore must accept excessively high merchant discounts. The paper attempts to shed light on this “must-take cards” view from two angles. First, the paper gives some operational content to the notion of “must-take card” through the “avoided-cost test” or “tourist test”: would the merchant want to refuse a card payment when a non-repeat customer with enough cash in her pocket is about to p...

  13. Implicit and explicit avoidance in sexual trauma victims suffering from posttraumatic stress disorder: a pilot study

    OpenAIRE

    Fleurkens, P.F.T.; Rinck, M.; Minnen, A. van

    2014-01-01

    Background: Avoidance of stimuli that are associated with the traumatic event is a key feature of posttraumatic stress disorder (PTSD). Thus far, studies on the role of avoidance in the development and maintenance of PTSD focused primarily on strategic or explicit avoidance. However, patients may also show implicit avoidance behavior, which may remain even when explicit avoidance is reduced. Objectives: The present pilot study was designed to test the hypothesis that PTSD patients show implic...

  14. European operative registry to avoid complications in operative gynecology.

    Science.gov (United States)

    Putz, Andreas; Bohlin, Tonje; Rakovan, Martin; Putz, Ariane Maria; De Wilde, Rudy Leon

    2016-08-01

    The aim of this study is to determine how complications can be avoided in gynecological minimally invasive surgery in Europe. The Norwegian Gynecological Endoscopic Registry (NGER) facilitates medical research over a long duration. Can experiences from the Norwegian registry be used to develop a European registry to avoid complications? To answer this question, we used the NGER data from February 2013 until March 2015 to analyze the complications of gynecological endoscopy. The registry includes sociodemographic factors, related comorbidity, previous surgery, present procedure, and intraoperative complications. Postoperative complications were identified with a questionnaire administered 4 weeks after surgery. The risk factors leading to complications in gynecological endoscopy were found to be obesity, diabetes mellitus, heart disease, hypertension, previous surgery due to cervical carcinoma in situ, and low educational level. Regional differences in the complication rate were noted. National web-based operation registries such as the NGER can identify the risk factors for complications of gynecological endoscopic surgery and can help improve the outcome after surgery. The experience from NGER can be used to establish a European register. PMID:26805611

  15. Tolerance and phenological avoidance of herbivory in tarweed species.

    Science.gov (United States)

    Krimmel, Billy; Pearse, Ian S

    2016-05-01

    Avoidance and tolerance of herbivory are important components of plant interactions with herbivores. Their relationship to each other and to plant defense is important in understanding how plants maximize fitness in the face of herbivore pressure. Various tarweed species have populations comprised of both early-season and late-season flowering individuals. Late-season flowering individuals employ a recently described indirect defense against herbivores in which the accumulation of dead insects on their sticky surfaces attracts predatory insects that eat herbivores. In two tarweed species (Hemizonia congesta and Madia elegans), we observed that key herbivores rarely interact with early-season individuals in the field, and early-season individuals did not invest in dense glandular trichomes that cause indirect defense. We conducted field and greenhouse bud-removal experiments to assess tolerance of M elegans to herbivore damage. We found that late-season individuals were more tolerant of simulated herbivory than early-season individuals in both the field and the greenhouse. Late-season individuals that were forced into an earlier phenology with a 24-h light cue lost their tolerance to simulated herbivory. One possible mechanism linking phenological avoidance of herbivores with decreased tolerance is that early-season individuals invested less in below-ground biomass than late-season individuals, which may accumulate belowground resources for regrowth at the expense of early flowering. PMID:27349109

  16. A Massive Spiral Galaxy in the Zone of Avoidance

    CERN Document Server

    Donley, J L; Koribalski, B S; Kraan-Korteweg, R C; Schröder, A; Staveley-Smith, L

    2006-01-01

    We report the discovery of a very HI-massive disk galaxy, HIZOA J0836-43, at a velocity of v_hel = 10689 km/s, corresponding to a distance of 148 Mpc (assuming H_0=75 km/s/Mpc). It was found during the course of a systematic HI survey of the southern Zone of Avoidance (|b| < 5 deg) with the multibeam system at the 64m Parkes radio telescope. Follow-up observations with the Australia Telescope Compact Array (ATCA) reveal an extended HI disk. We derive an HI mass of 7.5 x 10^10 Msun. Using the HI radius, we estimate a total dynamical mass of 1.4 x 10^12 Msun, similar to the most massive known disk galaxies such as Malin 1. HIZOA J0836-43 lies deep in the Zone of Avoidance (l, b = 262.48 deg, -1.64 deg) where the optical extinction is very high, A_B = 9.8. However, in the near-infrared wavebands, where the extinction is considerably lower, HIZOA J0836-43 is clearly detected by both DENIS and 2MASS. Deep AAT near-infrared (Ks and H-band) images show that HIZOA J0836-43 is an inclined disk galaxy with a promine...

  17. Neuroprotection by Radical Avoidance: Search for Suitable Agents

    Directory of Open Access Journals (Sweden)

    Rüdiger Hardeland

    2009-12-01

    Full Text Available Neurodegeneration is frequently associated with damage by free radicals. However, increases in reactive oxygen and nitrogen species, which may ultimately lead to neuronal cell death, do not necessarily reflect its primary cause, but can be a consequence of otherwise induced cellular dysfunction. Detrimental processes which promote free radical formation are initiated, e.g., by disturbances in calcium homeostasis, mitochondrial malfunction, and an age-related decline in the circadian oscillator system. Free radicals generated at high rates under pathophysiological conditions are insufficiently detoxified by scavengers. Interventions at the primary causes of dysfunction, which avoid secondary rises in radical formation, may be more efficient. The aim of such approaches should be to prevent calcium overload, to reduce mitochondrial electron dissipation, to support electron transport capacity, and to avoid circadian perturbations. l-Theanine and several amphiphilic nitrones are capable of counteracting excitotoxicity and/or mitochondrial radical formation. Resveratrol seems to promote mitochondrial biogenesis. Mitochondrial effects of leptin include attenuation of electron leakage. Melatonin combines all the requirements mentioned, additionally regulates anti- and pro-oxidant enzymes and is, with few exceptions, very well tolerated. In this review, the perspectives, problems and limits of drugs are compared which may be suitable for reducing the formation of free radicals.

  18. WORMHOLE ATTACK MITIGATION IN MANET: A CLUSTER BASED AVOIDANCE TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Subhashis Banerjee

    2014-01-01

    Full Text Available A Mobile Ad-Hoc Network (MANET is a self configuring, infrastructure less network of mobile devices connected by wireless links. Loopholes like wireless medium, lack of a fixed infrastructure, dynamic topology, rapid deployment practices, and the hostile environments in which they may be deployed, make MANET vulnerable to a wide range of security attacks and Wormhole attack is one of them. During this attack a malicious node captures packets from one location in the network, and tunnels them to another colluding malicious node at a distant point, which replays them locally. This paper presents a cluster based Wormhole attack avoidance technique. The concept of hierarchical clustering with a novel hierarchical 32- bit node addressing scheme is used for avoiding the attacking path during the route discovery phase of the DSR protocol, which is considered as the under lying routing protocol. Pinpointing the location of the wormhole nodes in the case of exposed attack is also given by using this method.

  19. Trust-based learning and behaviors for convoy obstacle avoidance

    Science.gov (United States)

    Mikulski, Dariusz G.; Karlsen, Robert E.

    2015-05-01

    In many multi-agent systems, robots within the same team are regarded as being fully trustworthy for cooperative tasks. However, the assumption of trustworthiness is not always justified, which may not only increase the risk of mission failure, but also endanger the lives of friendly forces. In prior work, we addressed this issue by using RoboTrust to dynamically adjust to observed behaviors or recommendations in order to mitigate the risks of illegitimate behaviors. However, in the simulations in prior work, all members of the convoy had knowledge of the convoy goal. In this paper, only the lead vehicle has knowledge of the convoy goals and the follow vehicles must infer trustworthiness strictly from lead vehicle performance. In addition, RoboTrust could only respond to observed performance and did not dynamically learn agent behavior. In this paper, we incorporate an adaptive agent-specific bias into the RoboTrust algorithm that modifies its trust dynamics. This bias is learned incrementally from agent interactions, allowing good agents to benefit from faster trust growth and slower trust decay and bad agents to be penalized with slower trust growth and faster trust decay. We then integrate this new trust model into a trust-based controller for decentralized autonomous convoy operations. We evaluate its performance in an obstacle avoidance mission, where the convoy attempts to learn the best speed and following distances combinations for an acceptable obstacle avoidance probability.

  20. Alcohol Detection and Automatic Drunken Drive Avoiding System

    Directory of Open Access Journals (Sweden)

    Prof. P. H. Kulkarni

    2014-04-01

    Full Text Available The main aim of this project is to design an embedded system for implementing a efficient alcohol detection system that will be useful to avoid accidents. There are many different types of accidents which occur in daily life. Accidents may cause due to many reasons it may be due to brake fail. Most often accidents occur due to over drunken person. Though there are laws to punish drunken drivers they cannot be fully implemented. Because traffic police cannot stand on every road to check each and every car driver whether he/she has drunk or not. This can be a major reason for accidents. So there is a need for a effective system to check drunken drivers. Therefore in order to avoid these accidents we have implemented a prototype project. In our project, Initially we check whether the person has drunken or not by using the MQ3 GAS sensor. In this system, sensor circuit is used to detect whether the alcohol was consumed by driver or not. To this end, we have designed such a system that when alcohol concentration is detected then car will be stopped and the related information will go to nearby location through GSM. This project is based on EMBEDDED C programming using AVR-AT mega 16 microcontroller.

  1. Future singularity avoidance in phantom dark energy models

    Energy Technology Data Exchange (ETDEWEB)

    Haro, Jaume de, E-mail: jaime.haro@upc.edu [Departament de Matemàtica Aplicada I, Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona (Spain)

    2012-07-01

    Different approaches to quantum cosmology are studied in order to deal with the future singularity avoidance problem. Our results show that these future singularities will persist but could take different forms. As an example we have studied the big rip which appear when one considers the state equation P = ωρ with ω < −1, showing that it does not disappear in modified gravity. On the other hand, it is well-known that quantum geometric effects (holonomy corrections) in loop quantum cosmology introduce a quadratic modification, namely proportional to ρ{sup 2}, in Friedmann's equation that replace the big rip by a non-singular bounce. However this modified Friedmann equation could have been obtained in an inconsistent way, what means that the obtained results from this equation, in particular singularity avoidance, would be incorrect. In fact, we will show that instead of a non-singular bounce, the big rip singularity would be replaced, in loop quantum cosmology, by other kind of singularity.

  2. On the importance sampling of self-avoiding walks

    CERN Document Server

    Bousquet-Mélou, Mireille

    2011-01-01

    In a 1976 paper published in Science, Knuth presented an algorithm to sample (non-uniform) self-avoiding walks crossing a square of side k. From this sample, he constructed an estimator for the number of such walks. The quality of this estimator is directly related to the (relative) variance of a certain random variable X_k. From his experiments, Knuth suspected that this variance was extremely large, so that the estimator would not be very efficient. A few years ago, Bassetti and Diaconis showed that, for a similar sampler that only generates walks consisting of North and East steps, the relative variance is O(\\sqrt k). In this note we go one step further by showing that, for walks consisting of North, South and East steps, the relative variance is of the order of 2^{k(k+1)}/(k+1)^{2k}, and thus much larger than exponential in k. We also obtain partial results for general self-avoiding walks, suggesting that the relative variance could be as large as \\mu^{k^2} for some \\mu>1. Knuth's algorithm is a basic exa...

  3. An Analytical Approach to Avoid Obstacles in Mobile Robot Navigation

    Directory of Open Access Journals (Sweden)

    Alexandre Santos Brandão

    2013-06-01

    Full Text Available A nonlinear supervised globally stable controller is proposed to reactively guide a mobile robot to avoid obstacles while seeking a goal. Whenever the robot detects an object nearby, its orientation is changed to be aligned with the tangent to the border of the obstacle. Then, the robot starts following it, looking for a feasible path to its goal. The supervisor is responsible for deciding which path to take when the robot faces some particular obstacle configurations that are quite difficult to deal with. Several simulations and experiments were run to validate the proposal, some of which are discussed here. To run the experiments, the proposed controller is programmed into the onboard computer of a real unicycle mobile platform, equipped with a laser range scanner. As for the simulations, the models of the same experimental setup were used. The final conclusion is that the nonlinear supervised controller proposed to solve the problem of avoiding obstacles during goal seeking has been validated, based on the theoretical analysis, and the simulated and experimental results.

  4. Cow's milk allergy in children, from avoidance to tolerance.

    Science.gov (United States)

    Calligaris, Lorenzo; Longo, Giorgio; Badina, Laura; Berti, Irene; Barbi, Egidio

    2014-03-01

    Food allergy is the primary cause of anaphylaxis in paediatric age affecting roughly 4% of children and their families worldwide, and requiring changes in dietary habits. The prognosis for food allergy in children has traditionally been regarded as good for the most frequent allergens, however the prognosis for cow's milk allergy in the pediatric age is currently considered to be worse than previously believed. There is now enough evidence that measures of avoidance for children at risk did not have any preventive effect whatsoever, but they still came to be counterproductive by avoiding the physiological interaction between food allergens and gastrointestinal mucosal immune system. Programs of specific oral tolerance induction (SOTI) have obtained interesting results in the treatment of food allergy supporting the idea that antigen exposure through gastrointestinal section is important to allow the development of tolerance. Nevertheless this approach is not yet considered "ready" for community recommendations. In this paper we describe our experience in the field of SOTI in children with cow's milk allergy. PMID:24450451

  5. Ondansetron blocks LiCl-induced conditioned place avoidance but not conditioned taste/flavor avoidance in rats

    OpenAIRE

    Rinaman, Linda; Saboury, Mitra; Litvina, Elizabeth

    2009-01-01

    The ability of an experimental agent to support conditioned taste/flavor avoidance (CT/FA) in rats often is interpreted as sufficient evidence that the agent produced a state of malaise or nausea. Paradoxically, however, CT/FA also is induced by certain drugs that support conditioned preferences in rats, suggesting that CT/FA is insufficient to reveal a negative hedonic state. The present study tested the hypothesis that the anti-nausea drug ondansetron (OND) would block the ability of nauseo...

  6. Implicit and explicit avoidance in sexual trauma victims suffering from posttraumatic stress disorder: a pilot study

    Directory of Open Access Journals (Sweden)

    Pascal Fleurkens

    2014-02-01

    Full Text Available Background: Avoidance of stimuli that are associated with the traumatic event is a key feature of posttraumatic stress disorder (PTSD. Thus far, studies on the role of avoidance in the development and maintenance of PTSD focused primarily on strategic or explicit avoidance. However, patients may also show implicit avoidance behavior, which may remain even when explicit avoidance is reduced. Objectives: The present pilot study was designed to test the hypothesis that PTSD patients show implicit avoidance of threatening, trauma-related stimuli. In addition, it was tested whether this avoidance behavior also occurs for other stimuli. Methods: The Approach-Avoidance Task was used as an indirect measure of avoidance. Participants were 16 women suffering from PTSD who had experienced a sexual trauma, and 23 healthy non-traumatized women. Using a joystick, they pulled pictures closer to themselves or pushed them away. The pictures varied in content, being either high-threat sexual, non-threat sexual, high-threat accident, or positive. Results: Compared to control participants, PTSD patients avoided high-threat sexual pictures, and the degree of avoidance was predicted by self-reported arousal level. Moreover, PTSD patients with high levels of self-reported explicit avoidance, depressive symptoms, and PTSD symptom severity also avoided high-threat accident pictures. Conclusions: These findings point to the possible importance of threat value instead of trauma-relatedness in explaining implicit avoidance. The results are discussed in light of cognitive-behavioral models of PTSD, and clinical implications are suggested.

  7. Implicit and explicit avoidance in sexual trauma victims suffering from posttraumatic stress disorder: a pilot study

    Science.gov (United States)

    Fleurkens, Pascal; Rinck, Mike; van Minnen, Agnes

    2014-01-01

    Background Avoidance of stimuli that are associated with the traumatic event is a key feature of posttraumatic stress disorder (PTSD). Thus far, studies on the role of avoidance in the development and maintenance of PTSD focused primarily on strategic or explicit avoidance. However, patients may also show implicit avoidance behavior, which may remain even when explicit avoidance is reduced. Objectives The present pilot study was designed to test the hypothesis that PTSD patients show implicit avoidance of threatening, trauma-related stimuli. In addition, it was tested whether this avoidance behavior also occurs for other stimuli. Methods The Approach-Avoidance Task was used as an indirect measure of avoidance. Participants were 16 women suffering from PTSD who had experienced a sexual trauma, and 23 healthy non-traumatized women. Using a joystick, they pulled pictures closer to themselves or pushed them away. The pictures varied in content, being either high-threat sexual, non-threat sexual, high-threat accident, or positive. Results Compared to control participants, PTSD patients avoided high-threat sexual pictures, and the degree of avoidance was predicted by self-reported arousal level. Moreover, PTSD patients with high levels of self-reported explicit avoidance, depressive symptoms, and PTSD symptom severity also avoided high-threat accident pictures. Conclusions These findings point to the possible importance of threat value instead of trauma-relatedness in explaining implicit avoidance. The results are discussed in light of cognitive-behavioral models of PTSD, and clinical implications are suggested. PMID:24563729

  8. Avoiding the pitfalls of adaptive management implementation in Swedish silviculture.

    Science.gov (United States)

    Rist, Lucy; Felton, Adam; Mårald, Erland; Samuelsson, Lars; Lundmark, Tomas; Rosvall, Ola

    2016-02-01

    There is a growing demand for alternatives to Sweden's current dominant silvicultural system, driven by a desire to raise biomass production, meet environmental goals and mitigate climate change. However, moving towards diversified forest management that deviates from well established silvicultural practices carries many uncertainties and risks. Adaptive management is often suggested as an effective means of managing in the context of such complexities. Yet there has been scepticism over its appropriateness in cases characterised by large spatial extents, extended temporal scales and complex land ownership-characteristics typical of Swedish forestry. Drawing on published research, including a new paradigm for adaptive management, we indicate how common pitfalls can be avoided during implementation. We indicate the investment, infrastructure, and considerations necessary to benefit from adaptive management. In doing so, we show how this approach could offer a pragmatic operational model for managing the uncertainties, risks and obstacles associated with new silvicultural systems and the challenges facing Swedish forestry. PMID:26744049

  9. Application of an ADS-B Sense and Avoid Algorithm

    Science.gov (United States)

    Arteaga, Ricardo; Kotcher, Robert; Cavalin, Moshe; Dandachy, Mohammed

    2016-01-01

    The National Aeronautics and Space Administration Armstrong Flight Research Center in Edwards, California is leading a program aimed towards integrating unmanned aircraft system into the national airspace system (UAS in the NAS). The overarching goal of the program is to reduce technical barriers associated with related safety issues as well as addressing challenges that will allow UAS routine access to the national airspace. This research paper focuses on three novel ideas: (1) A design of an integrated UAS equipped with Automatic Dependent Surveillance-Broadcast that constructs a more accurate state-based airspace model; (2) The use of Stratway Algorithm in a real-time environment; and (3) The verification and validation of sense and avoid performance and usability test results which provide a pilot's perspective on how our system will benefit the UAS in the NAS program for both piloted and unmanned aircraft.

  10. The International Double Taxation – causes and avoidance

    Directory of Open Access Journals (Sweden)

    Nicoleta Barbuta-Misu

    2009-10-01

    Full Text Available The politics and tax legislation being a manifestation of strict sovereignty of the State, the phenomenon of double taxation occursfrequently representing a difficult poison for the foreign trade activity, especially hindering investments abroad, technology transfer or proliferationoutside of the state of the companies’ branches. Therefore, international legal double taxation, by the repeated taxation of the income, it is anobstacle to the development of economic relations between states, reducing the revenue of the international operators and their interests in makinginvestment abroad. This paper presents the main causes that determine double taxation, its forms, i.e. the economic double taxation and theinternational legal double taxation, the need for eliminating the double taxation and avoidance methods.

  11. Adaptive Stress Testing of Airborne Collision Avoidance Systems

    Science.gov (United States)

    Lee, Ritchie; Kochenderfer, Mykel J.; Mengshoel, Ole J.; Brat, Guillaume P.; Owen, Michael P.

    2015-01-01

    This paper presents a scalable method to efficiently search for the most likely state trajectory leading to an event given only a simulator of a system. Our approach uses a reinforcement learning formulation and solves it using Monte Carlo Tree Search (MCTS). The approach places very few requirements on the underlying system, requiring only that the simulator provide some basic controls, the ability to evaluate certain conditions, and a mechanism to control the stochasticity in the system. Access to the system state is not required, allowing the method to support systems with hidden state. The method is applied to stress test a prototype aircraft collision avoidance system to identify trajectories that are likely to lead to near mid-air collisions. We present results for both single and multi-threat encounters and discuss their relevance. Compared with direct Monte Carlo search, this MCTS method performs significantly better both in finding events and in maximizing their likelihood.

  12. Nursing Home Resident Symptomatology Triggering Transfer: Avoiding Unnecessary Hospitalizations

    Directory of Open Access Journals (Sweden)

    Alyce S. Ashcraft

    2012-01-01

    Full Text Available The purpose of this study was to describe nursing home resident symptomatology and medical diagnoses associated with nursing home to hospital transfers. A retrospective chart review of documented transfers was conducted at a 120-bed, nonprofit urban Continuing Care Retirement Center nursing home facility located in the southwestern United States. The transferred residents (n=101 had seventy different medical diagnoses prior to hospital transfer with hypertension, coronary artery disease, and congestive heart failure most frequently reported. Most frequently reported symptomatology included fatigue, lethargy or weakness, shortness of breath, and change in level of consciousness. Multiple symptomatology was indicative of a wide variety of medical diagnoses. The diagnoses and symptomatology recorded in this paper identify the importance of strategic planning concerning assessment and communication of common nursing home resident symptomatology and the importance of basic nursing and diagnostic procedures for prevention of potentially avoidable hospitalizations.

  13. Directed self-avoiding walks in random media

    International Nuclear Information System (INIS)

    Two types of directed self-avoiding walks (SAW's), namely, three-choice directed SAW and outwardly directed SAW, have been studied on infinite percolation clusters on the square lattice in two dimensions. The walks on the percolation clusters are generated via a Monte Carlo technique. The longitudinal extension RN and the transverse fluctuation WN have been measured as a function of the number of steps N. Slight swelling is observed in the longitudinal direction on the random lattices. A crossover from shrinking to swelling of the transverse fluctuations is found at a certain length Nc of the walks. The exponents related to the transverse fluctuations are seen to be unchanged in the random media even as the percolation threshold is reached. The scaling function form of the extensions are verified

  14. Sequential Probability Ratio Test for Spacecraft Collision Avoidance Maneuver Decisions

    Science.gov (United States)

    Carpenter, J. Russell; Markley, F. Landis

    2013-01-01

    A document discusses sequential probability ratio tests that explicitly allow decision-makers to incorporate false alarm and missed detection risks, and are potentially less sensitive to modeling errors than a procedure that relies solely on a probability of collision threshold. Recent work on constrained Kalman filtering has suggested an approach to formulating such a test for collision avoidance maneuver decisions: a filter bank with two norm-inequality-constrained epoch-state extended Kalman filters. One filter models the null hypotheses that the miss distance is inside the combined hard body radius at the predicted time of closest approach, and one filter models the alternative hypothesis. The epoch-state filter developed for this method explicitly accounts for any process noise present in the system. The method appears to work well using a realistic example based on an upcoming, highly elliptical orbit formation flying mission.

  15. Session: Avoiding, minimizing, and mitigating avian and bat impacts

    International Nuclear Information System (INIS)

    This session at the Wind Energy and Birds/Bats workshop consisted of two presentations followed by a discussion/question answer period. The session addressed a variety of questions related to avoiding, minimizing, and mitigating the avian and bat impacts of wind power development including: what has been learned from operating turbines and mitigating impacts where they are unavoidable, such as at Altamont Pass WRA, and should there be mitigation measures such as habitat creation or land conservation where impacts occur. Other impact minimization and mitigation approaches discussed included: location and siting evaluations; options for construction and operation of wind facilities; turbine lighting; and the physical alignment/orientation. Titles and authors of the presentations were: 'Bird Fatalities in the Altamont Pass Wind Resource Area: A Case Study, Part II' by Carl Thelander and 'Prevention and Mitigation of Avian Impacts at Wind Power Facilities' by Paul Kerlinger

  16. Avoided level crossings in very highly charged ions

    Science.gov (United States)

    Beiersdorfer, P.; Scofield, J. H.; Brown, G. V.; Chen, M. H.; Hell, N.; Osterheld, A. L.; Vogel, D. A.; Wong, K. L.

    2016-05-01

    We report a systematic measurement of the (2p1/2 -13 d3/2) J =1 and (2s1/2 -13 p1/2) J =1 levels in 14 neonlike ions between Ba46 + and Pb72 + and document the effects of their avoided crossing near Z =68 . Strong mixing affects the oscillator strengths over a surprisingly wide range of atomic numbers and leads to the vanishing of one transition two atomic numbers below the crossing. The crossing voids the otherwise correct expectation that the (2p1/2 -13 d3/2) J =1 level energy is only weakly affected by quantum electrodynamics (QED). For about 10 atomic numbers surrounding the crossing, its QED contributions are anomalously large, attaining almost equality to those affecting the (2s1/2 -13 p1/2) J =1 level. As a result, the accuracy of energy level calculations appears compromised near the crossing.

  17. Escape and avoidance learning in the earthworm Eisenia hortensis

    Directory of Open Access Journals (Sweden)

    W. Jeffrey Wilson

    2014-01-01

    Full Text Available Interest in instrumental learning in earthworms dates back to 1912 when Yerkes concluded that they can learn a spatial discrimination in a T-maze. Rosenkoetter and Boice determined in the 1970s that the “learning” that Yerkes observed was probably chemotaxis and not learning at all. We examined a different form of instrumental learning: the ability to learn both to escape and to avoid an aversive stimulus. Freely moving “master” worms could turn off an aversive white light by increasing their movement; the behavior of yoked controls had no effect on the light. We demonstrate that in as few as 12 trials the behavior of the master worms comes under the control of this contingency.

  18. Simulating self-avoiding walks in bounded domains

    CERN Document Server

    Kennedy, Tom

    2011-01-01

    Let D be a domain in the plane containing the origin. We are interested in the ensemble of self-avoiding walks (SAW's) in D which start at the origin and end on the boundary of the domain. We introduce an ensemble of SAW's that we expect to have the same scaling limit. The advantage of our ensemble is that it can be simulated using the pivot algorithm. Our ensemble makes it possible to accurately study SLE predictions for the SAW in bounded simply connected domains. One such prediction is the distribution along the boundary of the endpoint of the SAW. We use the pivot algorithm to simulate our ensemble and study this density. In particular the lattice effects in this density that persist in the scaling limit are seen to be given by a purely local function.

  19. Adsorbed self-avoiding walks subject to a force

    International Nuclear Information System (INIS)

    We consider a self-avoiding walk model of polymer adsorption where the adsorbed polymer can be desorbed by the application of a force. In this paper the force is applied normal to the surface at the last vertex of the walk. We prove that the appropriate limiting free energy exists where there is an applied force and a surface potential term, and prove that this free energy is convex in appropriate variables. We then derive an expression for the limiting free energy in terms of the free energy without a force and the free energy with no surface interaction. Finally we show that there is a phase boundary between the adsorbed phase and the desorbed phase in the presence of a force, prove some qualitative properties of this boundary and derive bounds on the location of the boundary. (paper)

  20. Adsorbed self-avoiding walks subject to a force

    Science.gov (United States)

    Janse van Rensburg, E. J.; Whittington, S. G.

    2013-11-01

    We consider a self-avoiding walk model of polymer adsorption where the adsorbed polymer can be desorbed by the application of a force. In this paper the force is applied normal to the surface at the last vertex of the walk. We prove that the appropriate limiting free energy exists where there is an applied force and a surface potential term, and prove that this free energy is convex in appropriate variables. We then derive an expression for the limiting free energy in terms of the free energy without a force and the free energy with no surface interaction. Finally we show that there is a phase boundary between the adsorbed phase and the desorbed phase in the presence of a force, prove some qualitative properties of this boundary and derive bounds on the location of the boundary.

  1. Self-avoiding random walks on the hexagonal lattice

    International Nuclear Information System (INIS)

    The authors use the algorithm recently introduced by A. Berretti and A.D. Sokal to compute numerically the critical exponents for the self-avoiding random walk on the hexagonal lattice. They find γ = 1.3509 +/- 0.0057 +/- 0.0023; v = 0.7580 +/- 0.0049 +/- 0.0046; α = 0.519 +/- 0.082 +/- 0.077 where the first error is the systematic one due to corrections to scaling and the second is the statistical error. For the effective coordination number μ they find μ = 1.84779 +/- 0.00006 +/- 0.0017. The results support the Nienhuis conjecture γ = 43/32 and provide a rough numerical check of the hyperscaling relation dv = 2 - α. An additional analysis, taking the Nienhuis value of μ = (2 + 2/sup 1/2/)/sup 1/2/ for granted, gives γ = 1.3459 +/- 0.0040 +/- 0.0008

  2. Complex network classification using partially self-avoiding deterministic walks.

    Science.gov (United States)

    Gonçalves, Wesley Nunes; Martinez, Alexandre Souto; Bruno, Odemir Martinez

    2012-09-01

    Complex networks have attracted increasing interest from various fields of science. It has been demonstrated that each complex network model presents specific topological structures which characterize its connectivity and dynamics. Complex network classification relies on the use of representative measurements that describe topological structures. Although there are a large number of measurements, most of them are correlated. To overcome this limitation, this paper presents a new measurement for complex network classification based on partially self-avoiding walks. We validate the measurement on a data set composed by 40000 complex networks of four well-known models. Our results indicate that the proposed measurement improves correct classification of networks compared to the traditional ones. PMID:23020478

  3. The critical pulling force for self-avoiding walks

    Science.gov (United States)

    Beaton, Nicholas R.

    2015-04-01

    Self-avoiding walks (SAWs) are a simple and well-known model of long, flexible polymers in a good solvent. Polymers being pulled away from a surface by an external agent can be modelled with SAWs in a half-space, with a Boltzmann weight y={{e}f} associated with the pulling force. This model is known to have a critical point at a certain value yc of this Boltzmann weight, which is the location of a transition between the so-called free and ballistic phases. The value yc = 1 has been conjectured by several authors using numerical estimates. We provide a relatively simple proof of this result, and show that further properties of the free energy of this system can be determined by re-interpreting existing results about the two-point function of SAWs.

  4. Continuously varying exponents for oriented self-avoiding walks

    International Nuclear Information System (INIS)

    A two-dimensional conformal field theory with a conserved U(1) current vector J, when perturbed by the operator vector J 2, exhibits a line of fixed points along which the scaling dimensions of the operators with non-zero U(1) charge vary continuously. This result is applied to the problem of oriented polymers (self-avoiding walks) in which the short-range repulsive interactions between two segments depend on their relative orientation. While the exponent ν describing the fractal dimension of such walks remains fixed, the exponent γ, which gives the total number similar Nγ-1μN of such walks, is predicted to vary continuously with the energy difference. ((orig.))

  5. Complex network classification using partially self-avoiding deterministic walks

    CERN Document Server

    Gonçalves, Wesley Nunes; Bruno, Odemir Martinez

    2011-01-01

    Complex networks have attracted increasing interest from various fields of science. It has been demonstrated that each complex network model presents specific topological structures which characterize its connectivity and dynamics. Complex network classification rely on the use of representative measurements that model topological structures. Although there are a large number of measurements, most of them are correlated. To overcome this limitation, this paper presents a new measurement for complex network classification based on partially self-avoiding walks. We validate the measurement on a data set composed by 40.000 complex networks of four well-known models. Our results indicate that the proposed measurement improves correct classification of networks compared to the traditional ones.

  6. Efficient modularity optimization by self-avoiding walk

    CERN Document Server

    Bagnato, Guilherme de Guzzi; Travieso, Gonzalo

    2016-01-01

    Different kinds of random walks have showed to be useful in the study of the structural properties of complex networks. Among them, the restricted dynamics of the self-avoiding random walk (SAW), which reaches only unvisited vertices in the same walk, has been succesfully used in network exploration. SAWs are therefore a promising tool to investigate community structures in networks. Despite its importance, community detection remains an open problem due to the high computational complexity of the associated optimization problem and a lack of a unique formal definition of communities. In this work, we propose a SAW-based modularity optimization algorithm to extract the community distribution of a network that achieves high modularity scores. We combined SAW with principal component analyses to define the dissimilarity measure and use agglomerative hierarchical clustering. To evaluate the performance of this algorithm we compare it with three popular methods for community detection: Girvan-Newman, Fastgreedy a...

  7. Velocity Perception: Collision Handling Technique for Agent Avoidance Behavior

    Directory of Open Access Journals (Sweden)

    Nazreen Abdullasim

    2013-04-01

    Full Text Available Collision avoidance behavior is always about maintaining free collision between virtual objects. It is also about generating evasion routing for the agents in virtual environment such as in crowd simulation. It consists of three processes which are construction of Field of Vision, Collision handling and collision response. Constructing field of vision is always a daunting task and always in enigma for the designer because it is subjected towards agent’s perception which is varies to each of them. There are few attempts on designing field of vision based on the agent’s dynamic focus toward its surrounding. Therefore, we present a top down approach study from crowd simulation modeling until the collision handling level in order to identify the suitable crowd modeling for our approach. Hence, at the end of this paper we will be able to discuss the possible techniques for constructing agent’s field of vision and analyze its potential in crowd simulation environment.

  8. Avoiding failed reconstitution of ultradeformable liposomes upon dehydration.

    Science.gov (United States)

    Montanari, J; Roncaglia, D I; Lado, L A; Morilla, M J; Romero, E L

    2009-05-01

    Although freeze-drying is an ordinarily used technique to dehydrate conventional liposomes, we have found that ultradeformable liposomes (UDLs) suffered irreversible aggregation when rehydrated upon freeze-drying (99.4% water elimination), even in high sugar content (4/1 sucrose/lipid mass ratio). When dehydrated by speed vac and vacuum drying, two alternative techniques that rendered less pronounced dehydration (94.27 and 96.2% water elimination, respectively) and avoid ice formation, however, UDL could only be successfully rehydrated when vacuum dried in 4/1 sucrose/lipid mass ratios. Conventional liposomes, on the other hand, were successfully reconstituted upon dehydrated by the three methods in lower sugar content (2/1 sucrose/lipid mass ratio). These results indicated that the 27% mole sodium cholate within the UDL lipid matrix was responsible for a greater and differential mechanical sensitivity of the bilayers to the different dehydration stress, as compared to conventional liposomes. PMID:19429279

  9. Avoidable cancers in the Nordic countries. External environment

    DEFF Research Database (Denmark)

    Dreyer, L; Andersen, A; Pukkala, E

    1997-01-01

    , weak, and most of the available studies are limited by lack of adequate control of confounding factors and other methodological drawbacks. Limited evidence exists for a link between urban air pollution and lung cancer, with reported relative risks of 1.0-1.5. About one-third of the population of the...... Nordic countries, corresponding to 7.3 million people, lives in urban areas. If there is an excess risk associated with air pollution, the annual number of lung cancer cases around the year 2000 in the Nordic countries would range from 0 (no excess risk) to 1,800 (relative risk, 1.5). As the existence of...... a causal link between air pollution and cancer is not uncorroborated, measures for avoiding cancer from this source cannot be recommended....

  10. Avoidable cancers in the Nordic countries. Alcohol consumption

    DEFF Research Database (Denmark)

    Dreyer, L; Winther, J F; Andersen, A; Pukkala, E

    1997-01-01

    Alcohol intake is causally associated with cancers of the larynx, oral cavity, pharynx, oesophagus and liver. In all five Nordic countries, alcohol consumption increased substantially between 1965 (6.5 litres per adult per year) and 1975 (10 litres), but remained at about 10 litres between 1975 and...... alcohol drinking were eliminated. This corresponds to about 29% of all alcohol-related cancers, i.e. in the oesophagus (37%), oral cavity and pharynx (33%), larynx (29%) and liver (15%). About 2% of all cancers in men and 1% in women in the Nordic countries around the year 2000 will be caused by the...... 1985. The daily consumption of men during the period was substantially higher than that of women, and that of both men and women was higher in Denmark than in the other Nordic countries. In about 2000, an annual total of almost 1,300 cancer cases (1,000 in men and 300 in women) would be avoided if...

  11. Radar system on a large autonomous vehicle for personnel avoidance

    Science.gov (United States)

    Silvious, Jerry; Wellman, Ron; Tahmoush, Dave; Clark, John

    2010-04-01

    The US Army Research Laboratory designed, developed and tested a novel switched beam radar system operating at 76 GHz for use in a large autonomous vehicle to detect and identify roadway obstructions including slowly-moving personnel. This paper discusses the performance requirements for the system to operate in an early collision avoidance mode to a range of 150 meters and at speeds of over 20 m/s. We report the measured capabilities of the system to operate in these modes under various conditions, such as rural and urban environments, and on various terrains, such as asphalt and grass. Finally, we discuss the range-Doppler map processing capabilities that were developed to correct for platform motion and identify roadway vehicles and personnel moving at 1 m/s or more along the path of the system.

  12. Phase-space picture of resonance creation and avoided crossings

    International Nuclear Information System (INIS)

    Complex coordinate scaling (CCS) is used to calculate resonance eigenvalues and eigenstates for a system consisting of an inverted Gaussian potential and a monochromatic driving field. Floquet eigenvalues and Husimi distributions of resonance eigenfunctions are calculated using two different versions of CCS. The number of resonance states in this system increases as the strength of the driving field is increased, indicating that this system might have increased stability against ionization when the field strength is very high. We find that the newly created resonance states are scarred on unstable periodic orbits of the classical motion. The behavior of these periodic orbits as the field strength is increased may explain why there are more resonance states at high field strengths than at low field strengths. Close examination of an avoided crossing between resonance states shows that the two states exchange their structure, as in bound systems. This phenomenon might lead to interesting effects at certain field strengths

  13. Avoiding occlusal derangement in facial fractures: An evidence based approach

    Directory of Open Access Journals (Sweden)

    Derick Mendonca

    2013-01-01

    Full Text Available Facial fractures with occlusal derangement describe any fracture which directly or indirectly affects the occlusal relationship. Such fractures include dento-alveolar fractures in the maxilla and mandible, midface fractures - Le fort I, II, III and mandible fractures of the symphysis, parasymphysis, body, angle, and condyle. In some of these fractures, the fracture line runs through the dento-alveolar component whereas in others the fracture line is remote from the occlusal plane nevertheless altering the occlusion. The complications that could ensue from the management of maxillofacial fractures are predominantly iatrogenic, and therefore can be avoided if adequate care is exercised by the operating surgeon. This paper does not emphasize on complications arising from any particular technique in the management of maxillofacial fractures but rather discusses complications in general, irrespective of the technique used.

  14. Avoiding dual regulation of the Civilian Radioactive Waste Management Program

    International Nuclear Information System (INIS)

    The Office of Civilian Radioactive Waste Management (RW) has successfully negotiated the issuance of a Department of Energy (DOE) Headquarters Order that provides for exemption of RW from certain DOE directives. This exemption assures precedence of Nuclear Regulatory Commission (NRC) requirements in radiation protection, nuclear safety (including quality assurance), and safeguards and security of nuclear materials. This Order is necessary to avoid the unwarranted cost and potential confusion resulting from dual regulation of RW facilities and activities by DOE and NRC. Development of this Order involved a systematic review of applicable DOE directives and NRC requirements to identify potential overlaps and duplication when applied to the RW program. Following this review and extensive negotiations with appropriate DOE organizations responsible for directives development, this Order was issued as HQ 1321.1 on December 22, 1993

  15. Avoiding Loops and Packet Losses in Internet Service Protocol Networks

    Directory of Open Access Journals (Sweden)

    B. Priyanka

    2014-03-01

    Full Text Available Abstract - Even in well managed Large ISP networks, failures of links and routers are common. Due to these failures the routers update their routing tables. Transient loops can occur in the networks when the routers adapt their forwarding tables. In this paper, a new approach is proposed that lets the network converge to its optimal state without loops and the related packet lossless. The mechanism (OUTFC-Ordered Updating Technique with Fast Convergence is based on an ordering of the updates of the forwarding tables of the routers and fast convergence. Typically we have chosen a Network consisting of routers and Link costs for simulation. Link failures are simulated. Avoiding transient loops in each case is demonstrated, by constructing a Reverse Shortest Path Tree (RSPT.

  16. Trapping safety into rules how desirable or avoidable is proceduralization?

    CERN Document Server

    Bourrier, Mathilde

    2013-01-01

    Rules and procedures are key features for a modern organization to function. It is no surprise to see them to be paramount in safety management. As some sociologists argue, routine and rule following is not always socially resented. It can bring people comfort and reduce anxieties of newness and uncertainty. Facing constant unexpected events entails fatigue and exhaustion. There is also no doubt that proceduralization and documented activities have brought progress, avoided recurrent mistakes and allowed for 'best practices' to be adopted. However, it seems that the exclusive and intensive use of procedures today is in fact a threat to new progress in safety. There is an urgent need to consider this issue because there is doubt that the path chosen by many hazardous industries and activities is the most effective, safety wise, considering the safety level achieved today. As soon as safety is involved, there seems to be an irresistible push towards a wider scope of norms, procedures and processes, whatever the...

  17. How much climate change can be avoided by mitigation?

    Science.gov (United States)

    Washington, Warren M.; Knutti, Reto; Meehl, Gerald A.; Teng, Haiyan; Tebaldi, Claudia; Lawrence, David; Buja, Lawrence; Strand, Warren G.

    2009-04-01

    Avoiding the most serious climate change impacts will require informed policy decisions. This in turn will require information regarding the reduction of greenhouse gas emissions required to stabilize climate in a state not too much warmer than today. A new low emission scenario is simulated in a global climate model to show how some of the impacts from climate change can be averted through mitigation. Compared to a non-intervention reference scenario, emission reductions of about 70% by 2100 are required to prevent roughly half the change in temperature and precipitation that would otherwise occur. By 2100, the resulting stabilized global climate would ensure preservation of considerable Arctic sea ice and permafrost areas. Future heat waves would be 55% less intense, and sea level rise from thermal expansion would be about 57% lower than if a non-mitigation scenario was followed.

  18. Safe practice of cosmetic dermatology: Avoiding legal tangles

    Directory of Open Access Journals (Sweden)

    Sarvajnamurthy A Sacchidanand

    2012-01-01

    Full Text Available The present day dermatologists, in addition to conventional skin physicians, are also dermatologic-surgeons and cosmetologists in their practice. The cosmetic procedures have the inherent risk of malpractice litigations leaving an unsatisfied patient and a troublesome lawsuit against the doctor. A MEDLINE search was conducted for article with words such as legal issues and dermatology, malpractice in dermatology, safe practice of cosmetology etc. The selected articles are scrutinized and compiled so as to help the young dermatologists to have a comprehensive overview of safe cosmetology practice. This article aims at sensitizing the young dermatologists for the possible complications and provides an overview of safe practice. It also provides a list of simple routine precautions which helps the dermatologist to avoid unnecessary trips to the courthouse.

  19. Avoiding obstacles by using a proximity infrared sensor skin

    Institute of Scientific and Technical Information of China (English)

    Cao Zhengcai; Fu Yili; Wu Qidi; Wang Shuguo; Wang Guangguo

    2007-01-01

    Placement and wiring of vast amount of sensor elements on the 3-dimensionally configured robot surface to form soft sensor skin is very difficult with the traditional technology, hi this paper we propose a new method to realize such a skin. By implanting infrared sensors array in an elastic body, we obtain an elastic and tough sensor skin that can be shaped freely. The developed sensor skin is a large-area, flexible array of infrared sensors with data processing capabilities. Depending on the skin electronics, it endows its carrier with an ability to sense its surroundings. The structure, the method of infrared sensor signal processing, and basic experiments of sensor skin are presented. The validity of the infrared sensor skin is investigated by preliminary obstacle avoidance trial.

  20. Do Wild Great Tits Avoid Exposure to Light at Night?

    Directory of Open Access Journals (Sweden)

    Maaike de Jong

    Full Text Available Studies of wild populations have provided important insights into the effects of artificial light at night on organisms, populations and ecosystems. However, in most studies the exact amount of light at night individuals are exposed to remains unknown. Individuals can potentially control their nighttime light exposure by seeking dark spots within illuminated areas. This uncertainty makes it difficult to attribute effects to a direct effect of light at night, or to indirect effects, e.g., via an effect of light at night on food availability. In this study, we aim to quantify the nocturnal light exposure of wild birds in a previously dark forest-edge habitat, experimentally illuminated with three different colors of street lighting, in comparison to a dark control. During two consecutive breeding seasons, we deployed male great tits (Parus major with a light logger measuring light intensity every five minutes over a 24h period. We found that three males from pairs breeding in brightly illuminated nest boxes close to green and red lamp posts, were not exposed to more artificial light at night than males from pairs breeding further away. This suggests, based on our limited sample size, that these males could have been avoiding light at night by choosing a roosting place with a reduced light intensity. Therefore, effects of light at night previously reported for this species in our experimental set-up might be indirect. In contrast to urban areas where light is omnipresent, bird species in non-urban areas may evade exposure to nocturnal artificial light, thereby avoiding direct consequences of light at night.

  1. Whole-arm obstacle avoidance system conceptual design

    International Nuclear Information System (INIS)

    Whole-arm obstacle avoidance is needed for a variety of robotic applications in the Environmental Restoration and Waste Management (ER ampersand WM) Program. Typical industrial applications of robotics involve well-defined workspaces, allowing a predetermined knowledge of collision-free paths for manipulator motion. In the unstructured or poorly defined hazardous environments of the ER ampersand WM Program, the potential for significant problems resulting from collisions between manipulators and the environment in which they are utilized is great. The conceptual design for a sensing system that will provide protection against such collisions is described herein. The whole-arm obstacle avoidance system consists of a set of sensor ''bracelets,'' which cover the surface area of the manipulator links to the maximum extent practical, and a host processor. The host processor accepts commands from the robot control system, controls the operation of the sensors, manipulates data received from the bracelets, and makes the data available to the manipulator control system. The bracelets consist of a subset of the sensors, associated sensor interface electronics, and a bracelet interface. Redundant communications links between the host processor and the bracelets are provided, allowing single-point failure protection. The system allows reporting of 8-bit data from up to 1000 sensors at a minimum of 50 Hz. While the initial prototype implementation of the system utilizes capacitance proximity sensor, the system concept allows multiple types of sensors. These sensors are uniquely addressable, allowing remote calibration, thresholding at the bracelet, and correlation of a sensor measurement with the associated sensor and its location on the manipulator. Variable resolution allows high-speed, single-bit sensing as well as lower-speed higher-resolution sensing, which is necessary for sensor calibration and potentially useful in control

  2. Automated Conflict Resolution, Arrival Management and Weather Avoidance for ATM

    Science.gov (United States)

    Erzberger, H.; Lauderdale, Todd A.; Chu, Yung-Cheng

    2010-01-01

    The paper describes a unified solution to three types of separation assurance problems that occur in en-route airspace: separation conflicts, arrival sequencing, and weather-cell avoidance. Algorithms for solving these problems play a key role in the design of future air traffic management systems such as NextGen. Because these problems can arise simultaneously in any combination, it is necessary to develop integrated algorithms for solving them. A unified and comprehensive solution to these problems provides the foundation for a future air traffic management system that requires a high level of automation in separation assurance. The paper describes the three algorithms developed for solving each problem and then shows how they are used sequentially to solve any combination of these problems. The first algorithm resolves loss-of-separation conflicts and is an evolution of an algorithm described in an earlier paper. The new version generates multiple resolutions for each conflict and then selects the one giving the least delay. Two new algorithms, one for sequencing and merging of arrival traffic, referred to as the Arrival Manager, and the other for weather-cell avoidance are the major focus of the paper. Because these three problems constitute a substantial fraction of the workload of en-route controllers, integrated algorithms to solve them is a basic requirement for automated separation assurance. The paper also reviews the Advanced Airspace Concept, a proposed design for a ground-based system that postulates redundant systems for separation assurance in order to achieve both high levels of safety and airspace capacity. It is proposed that automated separation assurance be introduced operationally in several steps, each step reducing controller workload further while increasing airspace capacity. A fast time simulation was used to determine performance statistics of the algorithm at up to 3 times current traffic levels.

  3. Effect of Silver nanoparticles on Passive Avoidance learning in Rats

    Directory of Open Access Journals (Sweden)

    parvin khodarahmi

    2015-09-01

    Full Text Available Background & aim: Silver nanoparticles (Ag NPs have been widely used in many technologies to produce medical devices, food technology and textiles. Silver nanoparticles may be absorbed through the lungs and intestine into circulation and thus may reach such organs as the liver, kidney, spleen, heart and testes and brain. It has been demonstrated that silver nanoparticles may have toxic effects on mammalian cells. There are some alarming reports on the adverse effects of silver nanoparticles on reproduction of experimental animals. Exposure to silver nanoparticles may exert a neurotoxic effect and affect cognitive functions, causing the impairment of short-term and working memory. The purpose of this study was to investigate the possible protective role of Ag NP on the learning and memory of rats. Methods: The present experimental study was conducted on forty male Wistar rats weighing 200 to 250 g which were divided into five groups of eight as follows: control group and 4 groups of treatment. Control group rats received saline and treatment group’s rats received Ag NP at doses of 50, 250,500 and 1000 mg/ kg/ day using Intra Peritoneal injection (IP for 14 days. One day after the last injection, the learning and memory function in the rats was examined by the passive avoidance task. Measure of memory and learning were assessed using One-Way ANOVA by SPSS using the  Tukey s' test. Results: The results showed that Ag NP at dose of 50, 250, 500 mg/kg made no significant change in the STL (step-through latency and TDC (Time in Dark Compartment, compared to the control group in the passive avoidance task. Despite, Ag NP at dose of 1000 mg/kg significantly reduced the STL (p<0.01 and increased TDC (p0.05 compared to the control group. Conclusion: These data suggest that ip microinjection of Ag NP could impair learning and memory at high doses.

  4. Do Wild Great Tits Avoid Exposure to Light at Night?

    Science.gov (United States)

    de Jong, Maaike; Ouyang, Jenny Q.; van Grunsven, Roy H. A.; Visser, Marcel E.; Spoelstra, Kamiel

    2016-01-01

    Studies of wild populations have provided important insights into the effects of artificial light at night on organisms, populations and ecosystems. However, in most studies the exact amount of light at night individuals are exposed to remains unknown. Individuals can potentially control their nighttime light exposure by seeking dark spots within illuminated areas. This uncertainty makes it difficult to attribute effects to a direct effect of light at night, or to indirect effects, e.g., via an effect of light at night on food availability. In this study, we aim to quantify the nocturnal light exposure of wild birds in a previously dark forest-edge habitat, experimentally illuminated with three different colors of street lighting, in comparison to a dark control. During two consecutive breeding seasons, we deployed male great tits (Parus major) with a light logger measuring light intensity every five minutes over a 24h period. We found that three males from pairs breeding in brightly illuminated nest boxes close to green and red lamp posts, were not exposed to more artificial light at night than males from pairs breeding further away. This suggests, based on our limited sample size, that these males could have been avoiding light at night by choosing a roosting place with a reduced light intensity. Therefore, effects of light at night previously reported for this species in our experimental set-up might be indirect. In contrast to urban areas where light is omnipresent, bird species in non-urban areas may evade exposure to nocturnal artificial light, thereby avoiding direct consequences of light at night. PMID:27355354

  5. The first rapid assessment of avoidable blindness (RAAB in Thailand.

    Directory of Open Access Journals (Sweden)

    Saichin Isipradit

    Full Text Available BACKGROUND: The majority of vision loss is preventable or treatable. Population surveys are crucial for planning, implementation, and monitoring policies and interventions to eliminate avoidable blindness and visual impairments. This is the first rapid assessment of avoidable blindness (RAAB study in Thailand. METHODS: A cross-sectional study of a population in Thailand age 50 years old or over aimed to assess the prevalence and causes of blindness and visual impairments. Using the Thailand National Census 2010 as the sampling frame, a stratified four-stage cluster sampling based on a probability proportional to size was conducted in 176 enumeration areas from 11 provinces. Participants received comprehensive eye examination by ophthalmologists. RESULTS: The age and sex adjusted prevalence of blindness (presenting visual acuity (VA <20/400, severe visual impairment (VA <20/200 but ≥20/400, and moderate visual impairment (VA <20/70 but ≥20/200 were 0.6% (95% CI: 0.5-0.8, 1.3% (95% CI: 1.0-1.6, 12.6% (95% CI: 10.8-14.5. There was no significant difference among the four regions of Thailand. Cataract was the main cause of vision loss accounted for 69.7% of blindness. Cataract surgical coverage in persons was 95.1% for cut off VA of 20/400. Refractive errors, diabetic retinopathy, glaucoma, and corneal opacities were responsible for 6.0%, 5.1%, 4.0%, and 2.0% of blindness respectively. CONCLUSION: Thailand is on track to achieve the goal of VISION 2020. However, there is still much room for improvement. Policy refinements and innovative interventions are recommended to alleviate blindness and visual impairments especially regarding the backlog of blinding cataract, management of non-communicative, chronic, age-related eye diseases such as glaucoma, age-related macular degeneration, and diabetic retinopathy, prevention of childhood blindness, and establishment of a robust eye health information system.

  6. Alert System for High Speed Vehicles to Avoid Wildlife Accidents

    Directory of Open Access Journals (Sweden)

    Rana Biswas

    2016-01-01

    Full Text Available “Alert System for High Speed Vehicles to Avoid Wildlife Accidents” is an alert system used to safeguard our wildlife. We often hear of various accidents of wild animals like elephant, nilgai etc., who are trying to cross the railway track. So, an intelligent electronics system is necessary which can be affixed to avoid the possibilities of accidents. Regarding this, in our project we are using a Passive Infrared Sensor (PIR sensor which is an electronic sensor that measures infrared (IR light radiating from objects in its field of view and switches ON any electrical/electronic device to which it is connected to. The key component of the sensor module is the pyroelectric element. All objects with a temperature above absolute zero emit heat energy in the form of radiation. Usually this radiation is invisible to the human eye because it is radiated at infrared wavelengths, but it is detected by this PIR sensor. This sensor does not radiate any energy for detection purposes and thus, it has no harmful effects on living beings. In our project the PIR sensor is used as a part of a burglar alarm and the electronic in the PIR typically control a small relay. This relay completes the circuit across a pair of electrical contacts connected to a detection input zone of the burglar alarm control panel. The system is usually designed such that if no living creature is being detected, the relay contact is closed- a „normally closed‟ (NC relay. If energy emitted from any nearby creature is detected, the relay opens, triggering the alarm, a signal will be directly sent to the driver‟s chamber and it will create a message in the LED screen of his chamber also an alarm will be heard which we have implemented using an ultrasonic sensor hc-sr04.

  7. Reconstructive laparoscopic prolapse surgery to avoid mesh erosions

    Directory of Open Access Journals (Sweden)

    Devassy, Rajesh

    2013-09-01

    Full Text Available Introduction: The objective of the study is to examine the efficacy of the purely laparoscopic reconstructive management of cystocele and rectocele with mesh, to avoid the risk of erosion by the graft material, a well known complication in vaginal mesh surgery. Material and methods: We performed a prospective, single-case, non-randomized study in 325 patients who received laparoscopic reconstructive management of pelvic organe prolaps with mesh. The study was conducted between January 2004 and December 2012 in a private clinic in India. The most common prolapse symptoms were reducible vaginal lump, urinary stress incontinence, constipation and flatus incontinence, sexual dysfunction and dypareunia. The degree e of the prolaps was staged according to POPQ system. The approach was purely laparoscopic and involved the use of polypropylene (Prolene or polyurethane with activated regenerated cellulose coating (Parietex mesh. Results: The mean age was 55 (30–80 years and the most of the patients were multiparous (272/325. The patients received a plastic correction of the rectocele only (138 cases, a cystocele and rectocele (187 cases with mesh. 132 patients had a concomitant total hysterectomy; in 2 cases a laparoscopic supracervical hysterectomy was performed and 190 patients had a laparoscopic colposuspension. The mean operation time was 82.2 (60–210 minutes. The mean follow up was 3.4 (3–5 years. Urinary retention developed in 1 case, which required a new laparoscopical intervention. Bladder injury, observed in the same case was in one session closed with absorbable suture. There were four recurrences of the rectocele, receiving a posterior vaginal colporrhaphy. Erosions of the mesh were not reported or documented. Conclusion: The pure laparoscopic reconstructive management of the cystocele and rectocele with mesh seems to be a safe and effective surgical procedure potentially avoiding the risk of mesh erosions.

  8. Avoiding Drought Risks and Social Conflict Under Climate Change

    Science.gov (United States)

    Towler, E.; Lazrus, H.; Paimazumder, D.

    2014-12-01

    Traditional drought research has mainly focused on physical drought risks and less on the cultural processes that also contribute to how drought risks are perceived and managed. However, as society becomes more vulnerable to drought and climate change threatens to increase water scarcity, it is clear that drought research would benefit from a more interdisciplinary approach. To assess avoided drought impacts from reduced climate change, drought risks need to be assessed in the context of both climate prediction as well as improved understanding of socio-cultural processes. To this end, this study explores a risk-based framework to combine physical drought likelihoods with perceived risks from stakeholder interviews. Results are presented from a case study on how stakeholders in south-central Oklahoma perceive drought risks given diverse cultural beliefs, water uses, and uncertainties in future drought prediction. Stakeholder interviews (n=38) were conducted in 2012 to understand drought risks to various uses of water, as well as to measure worldviews from the cultural theory of risk - a theory that explains why people perceive risks differently, potentially leading to conflict over management decisions. For physical drought risk, drought projections are derived from a large ensemble of future climates generated from two RCPs that represent higher and lower emissions trajectories (i.e., RCP8.5 and RCP4.5). These are used to develop a Combined Drought Risk Matrix (CDRM) that characterizes drought risks for different water uses as the products of both physical likelihood (from the climate ensemble) and risk perception (from the interviews). We use the CRDM to explore the avoided drought risks posed to various water uses, as well as to investigate the potential for reduction of conflict over water management.

  9. Low-Cost Avoidance Behaviors Are Resistant To Fear Extinction In Humans

    OpenAIRE

    Bram eVervliet; Ellen eIndekeu

    2015-01-01

    Elevated levels of fear and avoidance are core symptoms across the anxiety disorders. It has long been known that fear serves to motivate avoidance. Consequently, fear extinction has been the primary focus in pre-clinical anxiety research for decades, under the implicit assumption that removing the motivator of avoidance (fear) would automatically mitigate the avoidance behaviors as well. Although this assumption has intuitive appeal, it has received little scientific scrutiny. The scarce evi...

  10. Low-Cost Avoidance Behaviors are Resistant to Fear Extinction in Humans

    OpenAIRE

    Vervliet, Bram; Indekeu, Ellen

    2015-01-01

    Elevated levels of fear and avoidance are core symptoms across the anxiety disorders. It has long been known that fear serves to motivate avoidance. Consequently, fear extinction has been the primary focus in pre-clinical anxiety research for decades, under the implicit assumption that removing the motivator of avoidance (fear) would automatically mitigate the avoidance behaviors as well. Although this assumption has intuitive appeal, it has received little scientific scrutiny. The scarce evi...

  11. Collapse transition of self-avoiding trails on the square lattice

    OpenAIRE

    Owczarek, A. L.; Prellberg, T.

    2006-01-01

    The collapse transition of an isolated polymer has been modelled by many different approaches, including lattice models based on self-avoiding walks and self-avoiding trails. In two dimensions, previous simulations of kinetic growth trails, which map to a particular temperature of interacting self-avoiding trails, showed markedly different behaviour for what was argued to be the collapse transition than that which has been verified for models based of self-avoiding walks. On the other hand, i...

  12. Adaptive Formation Control and Collision Avoidance Using a Priority Strategy for Nonholonomic Mobile Robots

    OpenAIRE

    Yanyan Dai; Kyung Sik Choi; Suk Gyu Lee

    2013-01-01

    This paper presents four novel collision avoidance processes for nonholonomic mobile robots to generate effective collision‐free trajectories when forming and maintaining a formation. A collision priority strategy integrates the static and dynamic collision priorities to avoid a collision efficiently and effectively. In addition, it minimizes the turning angle of the follower robot and decreases system computation time. When avoiding collisions between robots, a novel collision avoidance algo...

  13. Comparison and avoidance of toxicity of penetrating cryoprotectants.

    Directory of Open Access Journals (Sweden)

    Edyta A Szurek

    Full Text Available The objective of this study was to elucidate the toxicity of widely used penetrating cryoprotective agents (CPAs to mammalian oocytes. To this end, mouse metaphase II (M II oocytes were exposed to 1.5 M solutions of dimethylsulfoxide (DMSO, ethylene glycol (EG, or propanediol (PROH prepared in phosphate buffered saline (PBS containing 10% fetal bovine serum. To address the time- and temperature-dependence of the CPA toxicity, M II oocytes were exposed to the aforementioned CPAs at room temperature (RT, ∼23°C and 37°C for 15 or 30 minutes. Subsequently, the toxicity of each CPA was evaluated by examining post-exposure survival, fertilization, embryonic development, chromosomal abnormalities, and parthenogenetic activation of treated oocytes. Untreated oocytes served as controls. Exposure of MII oocytes to 1.5 M DMSO or 1.5 M EG at RT for 15 min did not adversely affect any of the evaluated criteria. In contrast, 1.5 M PROH induced a significant increase in oocyte degeneration (54.2% and parthenogenetic activation (16% under same conditions. When the CPA exposure was performed at 37°C, the toxic effect of PROH further increased, resulting in lower survival (15% and no fertilization while the toxicity of DMSO and EG was still insignificant. Nevertheless, it was possible to completely avoid the toxicity of PROH by decreasing its concentration to 0.75 M and combining it with 0.75 M DMSO to bring the total CPA concentration to a cryoprotective level. Moreover, combining lower concentrations (i.e., 0.75 M of PROH and DMSO significantly improved the cryosurvival of MII oocytes compared to the equivalent concentration of DMSO alone. Taken together, our results suggest that from the perspective of CPA toxicity, DMSO and EG are safer to use in slow cooling protocols while a lower concentration of PROH can be combined with another CPA to avoid its toxicity and to improve the cryosurvival as well.

  14. 50 CFR Table 19 to Part 679 - Seabird Avoidance Gear Codes

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Seabird Avoidance Gear Codes 19 Table 19... ALASKA Pt. 679, Table 19 Table 19 to Part 679—Seabird Avoidance Gear Codes VESSEL LOGBOOK CODE SEABIRD AVOIDANCE GEAR OR METHOD. 1 Paired Streamer Lines: Used during deployment of hook-and-line gear to...

  15. The Relation between Anxiety Disorder and Experiential Avoidance in Inpatient Adolescents

    Science.gov (United States)

    Venta, Amanda; Sharp, Carla; Hart, John

    2012-01-01

    The current study aimed to examine the relation between experiential avoidance and anxiety disorders, as well as the usefulness of the Avoidance and Fusion Questionnaire for Youth (AFQ-Y; Greco, Lambert, & Baer, 2008) in detecting anxiety disorder in a sample of adolescent inpatients. First, the relation between experiential avoidance and anxiety…

  16. Three-dimensional terminally attached self-avoiding walks and bridges

    OpenAIRE

    Clisby, Nathan; Conway, Andrew R; Guttmann, Anthony J.

    2015-01-01

    We study terminally attached self-avoiding walks and bridges on the simple cubic lattice, both by series analysis and Monte Carlo methods. We provide strong numerical evidence supporting a scaling relation between self-avoiding walks, bridges, and terminally attached self-avoiding walks, and posit that a corresponding amplitude ratio is a universal quantity.

  17. 22 CFR 40.105 - Former citizens who renounced citizenship to avoid taxation.

    Science.gov (United States)

    2010-04-01

    ... avoid taxation. 40.105 Section 40.105 Foreign Relations DEPARTMENT OF STATE VISAS REGULATIONS PERTAINING... Miscellaneous § 40.105 Former citizens who renounced citizenship to avoid taxation. An alien who is a former... avoid United States taxation, is ineligible for a visa under INA 212(a)(10)(E)....

  18. Lidar Sensors for Autonomous Landing and Hazard Avoidance

    Science.gov (United States)

    Amzajerdian, Farzin; Petway, Larry B.; Hines, Glenn D.; Roback, Vincent E.; Reisse, Robert A.; Pierrottet, Diego F.

    2013-01-01

    Lidar technology will play an important role in enabling highly ambitious missions being envisioned for exploration of solar system bodies. Currently, NASA is developing a set of advanced lidar sensors, under the Autonomous Landing and Hazard Avoidance (ALHAT) project, aimed at safe landing of robotic and manned vehicles at designated sites with a high degree of precision. These lidar sensors are an Imaging Flash Lidar capable of generating high resolution three-dimensional elevation maps of the terrain, a Doppler Lidar for providing precision vehicle velocity and altitude, and a Laser Altimeter for measuring distance to the ground and ground contours from high altitudes. The capabilities of these lidar sensors have been demonstrated through four helicopter and one fixed-wing aircraft flight test campaigns conducted from 2008 through 2012 during different phases of their development. Recently, prototype versions of these landing lidars have been completed for integration into a rocket-powered terrestrial free-flyer vehicle (Morpheus) being built by NASA Johnson Space Center. Operating in closed-loop with other ALHAT avionics, the viability of the lidars for future landing missions will be demonstrated. This paper describes the ALHAT lidar sensors and assesses their capabilities and impacts on future landing missions.

  19. Recycling Perovskite Solar Cells To Avoid Lead Waste.

    Science.gov (United States)

    Binek, Andreas; Petrus, Michiel L; Huber, Niklas; Bristow, Helen; Hu, Yinghong; Bein, Thomas; Docampo, Pablo

    2016-05-25

    Methylammonium lead iodide (MAPbI3) perovskite based solar cells have recently emerged as a serious competitor for large scale and low-cost photovoltaic technologies. However, since these solar cells contain toxic lead, a sustainable procedure for handling the cells after their operational lifetime is required to prevent exposure of the environment to lead and to comply with international electronic waste disposal regulations. Herein, we report a procedure to remove every layer of the solar cells separately, which gives the possibility to selectively isolate the different materials. Besides isolating the toxic lead iodide in high yield, we show that the PbI2 can be reused for the preparation of new solar cells with comparable performance and in this way avoid lead waste. Furthermore, we show that the most expensive part of the solar cell, the conductive glass (FTO), can be reused several times without any reduction in the performance of the devices. With our simple recycling procedure, we address both the risk of contamination and the waste disposal of perovskite based solar cells while further reducing the cost of the system. This brings perovskite solar cells one step closer to their introduction into commercial systems. PMID:27149009

  20. Tangent-point self-avoidance energies for curves

    CERN Document Server

    Strzelecki, Pawel

    2010-01-01

    We study a two-point self-avoidance energy $E_q$ which is defined for all rectifiable curves in $R^n$ as the double integral along the curve of $1/r^q$. Here $r$ stands for the radius of the (smallest) circle that is tangent to the curve at one point and passes through another point on the curve, with obvious natural modifications of this definition in the exceptional, non-generic cases. It turns out that finiteness of $E_q(\\gamma)$ for $q\\ge 2$ guarantees that $\\gamma$ has no self-intersections or triple junctions and therefore must be homeomorphic to the unit circle or to a closed interval. For $q>2$ the energy $E_q$ evaluated on curves in $R^3$ turns out to be a knot energy separating different knot types by infinite energy barriers and bounding the number of knot types below a given energy value. We also establish an explicit upper bound on the Hausdorff-distance of two curves in $R^3$ with finite $E_q$-energy that guarantees that these curves are ambient isotopic. This bound depends only on $q$ and the e...

  1. Avian Information Systems: Developing Web-Based Bird Avoidance Models

    Directory of Open Access Journals (Sweden)

    Jelmer van Belle

    2008-12-01

    Full Text Available Collisions between aircraft and birds, so-called “bird strikes,” can result in serious damage to aircraft and even in the loss of lives. Information about the distribution of birds in the air and on the ground can be used to reduce the risk of bird strikes and their impact on operations en route and in and around air fields. Although a wealth of bird distribution and density data is collected by numerous organizations, these data are not readily available nor interpretable by aviation. This paper presents two national efforts, one in the Netherlands and one in the United States, to develop bird avoidance nodels for aviation. These models integrate data and expert knowledge on bird distributions and migratory behavior to provide hazard maps in the form of GIS-enabled Web services. Both models are in operational use for flight planning and flight alteration and for airfield and airfield vicinity management. These models and their presentation on the Internet are examples of the type of service that would be very useful in other fields interested in species distribution and movement information, such as conservation, disease transmission and prevention, or assessment and mitigation of anthropogenic risks to nature. We expect that developments in cyber-technology, a transition toward an open source philosophy, and higher demand for accessible biological data will result in an increase in the number of biological information systems available on the Internet.

  2. Birds flush early and avoid the rush: an interspecific study.

    Directory of Open Access Journals (Sweden)

    Diogo S M Samia

    Full Text Available Since 1986, studies about the escape decisions made by prey are grounded in optimal escape theory (OET which states that prey will initiate escape when the risk of remaining and the costs of leaving are equal. However, a recent hypothesis, Flush Early and Avoid the Rush (FEAR, acknowledged that the cost of monitoring approaching predators might be a ubiquitous cost. The FEAR hypothesis predicts that prey will generally flee soon after they detect a predator so as to minimize the costs incurred by monitoring the predator. Knowing whether animals flee to reduce monitoring costs is of applied interest because wildlife managers use escape behavior to create set-back zones to reduce human-wildlife conflict. Here we provide the most comprehensive assessment of the FEAR hypothesis using data collected from 178 bird species representing 67 families from two continents. The FEAR hypothesis explains escape behavior in 79% of studied species. Because the FEAR hypothesis is a widespread phenomenon that drives escape behavior in birds, alert distance must be systematically incorporated into the design of set-back zones to protect vulnerable species.

  3. Avoiding Weight Gain in Cardiometabolic Disease: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Nisa M. Maruthur

    2014-01-01

    Full Text Available Patients with cardiometabolic disease are at higher risk for obesity-related adverse effects. Even without weight loss, weight maintenance may be beneficial. We performed a systematic review to identify the effect of nonweight loss-focused lifestyle interventions in adults with cardiometabolic disease. We searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials to identify comparative studies of lifestyle interventions (self-management, diet, exercise, or their combination without a weight loss focus in adults with or at risk for diabetes and cardiovascular disease. Weight, BMI, and waist circumference at ≥12 months were the primary outcomes. Of 24,870 citations, we included 12 trials (self-management, n=2; diet, n=2; exercise, n=2; combination, n=6 studying 4,206 participants. Self-management plus physical activity ± diet versus minimal/no intervention avoided meaningful weight (−0.65 to −1.3 kg and BMI (−0.4 to −0.7 kg/m2 increases. Self-management and/or physical activity prevented meaningful waist circumference increases versus control (−2 to −4 cm. In patients with cardiometabolic disease, self-management plus exercise may prevent weight and BMI increases and self-management and/or exercise may prevent waist circumference increases versus minimal/no intervention. Future studies should confirm these findings and evaluate additional risk factors and clinical outcomes.

  4. Recommendations to avoid gross errors of dose in radiotherapeutic treatments

    International Nuclear Information System (INIS)

    Human mistakes are an important source of errors in radiotherapy and may occur at every step of the radiotherapy planning and treatment. To reduce this level of uncertainties, several specialized organizations have recommended a comprehensive quality assurance program. In Brazil, the requirement for these programs has been strongly stressed, and most radiotherapy services have pursued this goal regarding radiation units and dosimetry equipment, as well as the verification of the calculations of the patient's dose and the revision of the plan charts. As a contribution to the improvement of quality control, we present some recommendations to avoid failure of treatment due to error in the delivered dose, such as redundant check of the manual or computer calculations, weekly check of the total dose for each patient, and prevention of inadvertent access to any safety system of the equipment by any staff member that is only supposed to operate the machine. Moreover, the use of a computerized treatment record and verification system should be considered in order to eliminate errors due to incorrect selection of the treatment parameters, in a daily basis. We report four radioactive incidents with patient injuries occurred throughout the world and some gross errors of dose. (author)

  5. Imidacloprid alters foraging and decreases bee avoidance of predators.

    Directory of Open Access Journals (Sweden)

    Ken Tan

    Full Text Available Concern is growing over the effects of neonicotinoid pesticides, which can impair honey bee cognition. We provide the first demonstration that sublethal concentrations of imidacloprid can harm honey bee decision-making about danger by significantly increasing the probability of a bee visiting a dangerous food source. Apis cerana is a native bee that is an important pollinator of agricultural crops and native plants in Asia. When foraging on nectar containing 40 µg/L (34 ppb imidacloprid, honey bees (Apis cerana showed no aversion to a feeder with a hornet predator, and 1.8 fold more bees chose the dangerous feeder as compared to control bees. Control bees exhibited significant predator avoidance. We also give the first evidence that foraging by A. cerana workers can be inhibited by sublethal concentrations of the pesticide, imidacloprid, which is widely used in Asia. Compared to bees collecting uncontaminated nectar, 23% fewer foragers returned to collect the nectar with 40 µg/L imidacloprid. Bees that did return respectively collected 46% and 63% less nectar containing 20 µg/L and 40 µg/L imidacloprid. These results suggest that the effects of neonicotinoids on honey bee decision-making and other advanced cognitive functions should be explored. Moreover, research should extend beyond the classic model, the European honey bee (A. mellifera, to other important bee species.

  6. Imidacloprid Alters Foraging and Decreases Bee Avoidance of Predators

    Science.gov (United States)

    Tan, Ken; Chen, Weiwen; Dong, Shihao; Liu, Xiwen; Wang, Yuchong; Nieh, James C.

    2014-01-01

    Concern is growing over the effects of neonicotinoid pesticides, which can impair honey bee cognition. We provide the first demonstration that sublethal concentrations of imidacloprid can harm honey bee decision-making about danger by significantly increasing the probability of a bee visiting a dangerous food source. Apis cerana is a native bee that is an important pollinator of agricultural crops and native plants in Asia. When foraging on nectar containing 40 µg/L (34 ppb) imidacloprid, honey bees (Apis cerana) showed no aversion to a feeder with a hornet predator, and 1.8 fold more bees chose the dangerous feeder as compared to control bees. Control bees exhibited significant predator avoidance. We also give the first evidence that foraging by A. cerana workers can be inhibited by sublethal concentrations of the pesticide, imidacloprid, which is widely used in Asia. Compared to bees collecting uncontaminated nectar, 23% fewer foragers returned to collect the nectar with 40 µg/L imidacloprid. Bees that did return respectively collected 46% and 63% less nectar containing 20 µg/L and 40 µg/L imidacloprid. These results suggest that the effects of neonicotinoids on honey bee decision-making and other advanced cognitive functions should be explored. Moreover, research should extend beyond the classic model, the European honey bee (A. mellifera), to other important bee species. PMID:25025334

  7. Galaxy peculiar velocities in the Zone of Avoidance

    CERN Document Server

    Said, K; Jarrett, T H

    2014-01-01

    Dust extinction and stellar confusion of the Milky Way hinder the detection of galaxies at low Galactic latitude, creating the so-called Zone of Avoidance (ZoA). This has hampered our understanding of the local dynamics, cosmic flow fields and the origin of the Cosmic Microwave Background dipole. The ZoA ($|b| \\le 5^\\circ$) is also excluded from the "whole-sky" Two Micron All-Sky Survey (2MASS) Redshift Survey (2MRS) and 2MASS Tully-Fisher Survey (2MTF). The latter aims to provide distances and peculiar velocities for all bright inclined 2MASS galaxies with $K_s^o$ $\\leq 11\\hbox{$.\\!\\!^{\\rm m}$}25$. Correspondingly, knowledge about the density distribution in the ZoA remains limited to statistical interpolations. To improve on this bias we pursued two different surveys to fill in the southern and northern ZoA. These data will allow a direct measurement of galaxy peculiar velocities. In this paper we will present a newly derived optimized Tully-Fisher (TF) relation that allow accurate measures of galaxy distan...

  8. 2MASS Extended Sources in the Zone of Avoidance

    CERN Document Server

    Jarrett, T H; Cutri, R M; Schneider, S; Rosenberg, J; Huchra, J P; Mader, J

    2000-01-01

    The Two Micron All Sky Survey (2MASS) is now underway and will provide a complete census of galaxies as faint as 13.5 mag (3 mJy) at 2.2 microns for most of the sky, and ~12.1 mag (10 mJy) for regions veiled by the Milky Way. This census has already discovered nearby galaxies previously hidden behind our Galaxy, and will allow delineation of large-scale structures in the distribution of galaxies across the whole sky. Here we report the detection and discovery of new extended sources from this survey for fields incorporating the Galactic plane at longitudes between 40 and 70 deg. The area-normalized detection rate is ~1-2 galaxies per deg^2 brighter than 12.1 mag (10 mJy), roughly constant with Galactic latitude throughout the "Zone of Avoidance", of which 85-95% are newly discovered sources. In conjunction with the deep HI surveys, 2MASS will greatly increase the current census of galaxies hidden behind the Milky Way.

  9. Avoiding Errors in the Management of Pediatric Polytrauma Patients.

    Science.gov (United States)

    Chin, Kenneth; Abzug, Joshua; Bae, Donald S; Horn, Bernard D; Herman, Martin; Eberson, Craig P

    2016-01-01

    Management of pediatric polytrauma patients is one of the most difficult challenges for orthopaedic surgeons. Multisystem injuries frequently include complex orthopaedic surgical problems that require intervention. The physiology and anatomy of children and adolescent trauma patients differ from the physiology and anatomy of an adult trauma patient, which alters the types of injuries sustained and the ideal methods for management. Errors of pediatric polytrauma care are included in two broad categories: missed injuries and inadequate fracture treatment. Diagnoses may be missed most frequently because of a surgeon's inability to reliably assess patients who have traumatic brain injuries and painful distracting injuries. Cervical spine injuries are particularly difficult to identify in a child with polytrauma and may have devastating consequences. In children who have multiple injuries, the stabilization of long bone fractures with pediatric fixation techniques, such as elastic nails and other implants, allows for easier care and more rapid mobilization compared with cast treatments. Adolescent polytrauma patients who are approaching skeletal maturity, however, are ideally treated as adults to avoid complications, such as loss of fixation, and to speed rehabilitation. PMID:27049202

  10. Characterizing socially avoidant and affiliative responses to social exclusion

    Directory of Open Access Journals (Sweden)

    Katherine Elizabeth Powers

    2012-07-01

    Full Text Available Humans have a fundamental need for social relationships. From an evolutionary standpoint, the drive to form social connections may have evolved as an adaptive mechanism to promote survival, as group membership afforded the benefits of shared resources and security. Thus, rejection from social groups is especially detrimental, rendering the ability to detect threats to social relationships and respond in adaptive ways critical. Previous research indicates that social exclusion alters cognition and behavior in specific ways that may initially appear contradictory. That is, although some studies have found that exclusionary social threats lead to withdrawal from the surrounding social world, other studies indicate that social exclusion motivates affiliative social behavior. Here, we review the existing evidence supporting accounts of avoidant and affiliative responses, and highlight the conditions under which both categories of responses may be simultaneously employed. Then, we review the neuroimaging research implicating specific brain regions underlying the ability to detect and adaptively respond to threats of social exclusion. Collectively, these findings are suggestive of neural system highly attuned to social context and capable of motivating flexible behavioral responses.

  11. Discovery of Highly Obscured Galaxies in the Zone of Avoidance

    CERN Document Server

    Marleau, F R; Paladini, R; Clancy, D; Carey, S; Shenoy, S; Kraemer, K E; Kuchar, T; Mizuno, D R; Price, S

    2008-01-01

    We report the discovery of twenty-five previously unknown galaxies in the Zone of Avoidance. Our systematic search for extended extra-galactic sources in the GLIMPSE and MIPSGAL mid-infrared surveys of the Galactic plane has revealed two overdensities of these sources, located around l ~ 47 and 55 degrees and |b| less than 1 degree in the Sagitta-Aquila region. These overdensities are consistent with the local large-scale structure found at similar Galactic longitude and extending from |b| ~ 4 to 40 degrees. We show that the infrared spectral energy distribution of these sources is indeed consistent with those of normal galaxies. Photometric estimates of their redshift indicate that the majority of these galaxies are found in the redshift range z = 0.01 - 0.05, with one source located at z = 0.07. Comparison with known sources in the local Universe reveals that these galaxies are located at similar overdensities in redshift space. These new galaxies are the first evidence of a bridge linking the large-scale s...

  12. SECONDARY PHYSICAL EDUCATION AVOIDANCE AND GENDER: PROBLEMS AND ANTIDOTES

    Directory of Open Access Journals (Sweden)

    Thomas Ryan

    2012-07-01

    Full Text Available Our goal was to locate and evaluate the barriers that impact and cause females to avoid secondary elective physical education courses. We sought to find answers to stop the further decline of female enrolment in secondary physical education by looking into curricula, program and instructional variables. Anecdotal evidence informed this study which was very much exploratory, building upon several key facts. First, Ontario (Canada secondary students are only required to take one credit (course in physical education in order to graduate and second, most students take the required physical education course in grade nine which is their first year of high school. Following this there is an average of 10% fewer females in every physical education class in the province of Ontario and only an average of 12% are enrolled in physical education each year. Several issues were identified and explored including self-confidence; motivation; perceived value of physical activity; opportunities for physical activity; marking scheme; competition; co-ed classes; teaching approach; and peers as possible problems and solutions.

  13. A Novel Modeling Approach for Collision Avoidance in Robotic Surgery

    Directory of Open Access Journals (Sweden)

    Reza Ramezanifard

    2007-01-01

    Full Text Available We present a new system that can be used in combination with an array of ultrasonic piezoelectric sensors and has application in surgical navigation procedures. Using the proposed assembly, the maneuverability of the surgical tools can be enhanced and the incidence of potentially damaging contact with non-target tissue can be reduced. The emphasis of our work was based on controlling the motion of the surgical tools so that they can readily move around a biological tissue. According to the results of the simulation performed, the direction of the tool can be monitored and controlled continuously and hence the outcome of the surgery can be improved. Another important parameter that incorporated in the simulation was the distance between the tool and the tissue. The simulation results show that the proper control of the tool movement can keep the distance between the two at a certain predetermined value while the tool passing by the tissue. In the collision avoidance scheme, the transducers located on the lateral side of the surgical tool mainly act as the distance detector to keep the distance between the lateral surface of the tool and the tissue surface at a constant value of 5 mm.

  14. Pulling adsorbed self-avoiding walks from a surface

    Science.gov (United States)

    Guttmann, Anthony J.; Jensen, I.; Whittington, S. G.

    2014-01-01

    We consider a self-avoiding walk model of polymer adsorption where the adsorbed polymer can be desorbed by the application of a force, concentrating on the case of the square lattice. Using series analysis methods we investigate the behaviour of the free energy of the system when there is an attractive potential ɛ with the surface and a force f applied at the last vertex, normal to the surface, and extract the phase boundary between the ballistic and adsorbed phases. We believe this to be exact to graphical accuracy. We give precise estimates of the location of the transition from the free phase to the ballistic phase, which we find to be at yc = exp (f/kBTc) = 1, and from the free phase to the adsorbed phase, which we estimate to be at ac = exp ( - ɛ/kBTc) = 1.775 615 ± 0.000 005. In addition we prove that the phase transition from the ballistic to the adsorbed phase is first order.

  15. Microcanonical simulations of adsorbing self-avoiding walks

    Science.gov (United States)

    Janse van Rensburg, E. J.

    2016-03-01

    Linear polymers adsorbing on a wall can be modelled by half-space self-avoiding walks adsorbing on a line in the square lattice, or on a surface in the cubic lattice. In this paper a numerical approach based on the GAS algorithm is used to approximately enumerate states in the partition function of this model. The data are used to approximate the free energy in the model, from which estimates of the location of the critical point and crossover exponents are made. The critical point is found to be located at \\begin{equation} a_c^+ = \\cases{ 1.779 \\pm 0.003, & \\hbox{in the square lattice}; \\\\ 1.306 \\pm 0.007, & \\hbox{in the cubic lattice}. } \\end{equation} These results are then used to estimate the crossover exponent $\\phi$ associated with the adsorption transition, giving \\begin{equation} \\phi = \\cases{ 0.496 \\pm 0.009, & \\hbox{in two dimensions}; \\\\ 0.505 \\pm 0.006, & \\hbox{in three dimensions}. } \\end{equation} In addition, the scaling of these thermodynamic quantities is examined using the numerical data, including the scaling of metric quantities, and the partition and generating functions. In all cases results and numerical values of exponents were obtained which are consistent with estimates in the literature.

  16. Self-avoiding walks in a slab: rigorous results

    International Nuclear Information System (INIS)

    A polymer in the confined spaces between colloid particles loses entropy and exerts a repulsive entropic force on the confining particles. This situation can be modelled by a self-avoiding walk confined in a slab between two parallel planes in the lattice. In this paper, we prove the existence of a limiting free energy for the general case that the walk is interacting with the parallel bounding planes. We also prove that the limiting free energy is strictly increasing with the distance between the bounding planes in some regions of the phase diagram. These results demonstrate the presence of a non-zero repulsive entropic force in the model. Finally, we also examine the relation between the limiting free energy in this model and the limiting free energy in a model of walks adsorbing onto a single plane. We prove that these limiting free energies are equal in some regions of the phase diagram in the limit that the width of the slab between the parallel bounding planes is taken to infinity

  17. Pulling adsorbed self-avoiding walks from a surface

    International Nuclear Information System (INIS)

    We consider a self-avoiding walk model of polymer adsorption where the adsorbed polymer can be desorbed by the application of a force, concentrating on the case of the square lattice. Using series analysis methods we investigate the behaviour of the free energy of the system when there is an attractive potential ϵ with the surface and a force f applied at the last vertex, normal to the surface, and extract the phase boundary between the ballistic and adsorbed phases. We believe this to be exact to graphical accuracy. We give precise estimates of the location of the transition from the free phase to the ballistic phase, which we find to be at yc = exp (f/kBTc) = 1, and from the free phase to the adsorbed phase, which we estimate to be at ac = exp ( − ϵ/kBTc) = 1.775 615 ± 0.000 005. In addition we prove that the phase transition from the ballistic to the adsorbed phase is first order. (paper)

  18. Self-avoiding walks on scale-free networks.

    Science.gov (United States)

    Herrero, Carlos P

    2005-01-01

    Several kinds of walks on complex networks are currently used to analyze search and navigation in different systems. Many analytical and computational results are known for random walks on such networks. Self-avoiding walks (SAW's) are expected to be more suitable than unrestricted random walks to explore various kinds of real-life networks. Here we study long-range properties of random SAW's on scale-free networks, characterized by a degree distribution P(k) approximately k(-gamma). In the limit of large networks (system size N-->infinity), the average number sn of SAW's starting from a generic site increases as mu(n) , with mu = k2/k-1 . For finite N, sn is reduced due to the presence of loops in the network, which causes the emergence of attrition of the paths. For kinetic growth walks, the average maximum length L increases as a power of the system size: L approximately Nalpha, with an exponent alpha increasing as the parameter gamma is raised. We discuss the dependence of alpha on the minimum allowed degree in the network. A similar power-law dependence is found for the mean self-intersection length of nonreversal random walks. Simulation results support our approximate analytical calculations. PMID:15697654

  19. Image Degradation in Microscopic Images: Avoidance, Artifacts, and Solutions.

    Science.gov (United States)

    Roels, Joris; Aelterman, Jan; De Vylder, Jonas; Lippens, Saskia; Luong, Hiêp Q; Guérin, Christopher J; Philips, Wilfried

    2016-01-01

    The goal of modern microscopy is to acquire high-quality image based data sets. A typical microscopy workflow is set up in order to address a specific biological question and involves different steps. The first step is to precisely define the biological question, in order to properly come to an experimental design for sample preparation and image acquisition. A better object representation allows biological users to draw more reliable scientific conclusions. Image restoration can manipulate the acquired data in an effort to reduce the impact of artifacts (spurious results) due to physical and technical limitations, resulting in a better representation of the object of interest. However, precise usage of these algorithms is necessary so as to avoid further artifacts that might influence the data analysis and bias the conclusions. It is essential to understand image acquisition, and how it introduces artifacts and degradations in the acquired data, so that their effects on subsequent analysis can be minimized. This paper provides an overview of the fundamental artifacts and degradations that affect many micrographs. We describe why artifacts appear, in what sense they impact overall image quality, and how to mitigate them by first improving the acquisition parameters and then applying proper image restoration techniques. PMID:27207362

  20. Personality and mood correlates of avoidant personality disorder.

    Science.gov (United States)

    Meyer, Björn

    2002-04-01

    Avoidant personality disorder (APD) has been recognized as prevalent and clinically important; however, it is not clear how APD maps onto established personality and mood dimensions. In this cross-sectional survey study, 365 college students completed questionnaires assessing APD features and theoretically relevant personality and mood dimensions. Based on these self-report data, 6.6% may meet DSM-IV criteria for APD. Hierarchical regression analyses showed that APD features were associated with introversion, neuroticism, low self-esteem, and pessimistic expectancies. Additionally, APD features were linked with self-reports of elevated emotional responsiveness to threats and reduced emotional responsiveness to incentives (the behavioral inhibition system and behavioral activation system scales). After controlling for the effects of other personality, temperament, and cognitive measures, affective distress (i.e., anger, anxiety, and depression) was no longer related to APD. Results are consistent with APD models that emphasize the joint influences of emotional vulnerability and social-cognitive triggering and sustaining factors. PMID:12004493